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Sample records for genetic linkage maps

  1. Constructing dense genetic linkage maps

    NARCIS (Netherlands)

    Jansen, J.; Jong, de A.G.; Ooijen, van J.W.

    2001-01-01

    This paper describes a novel combination of techniques for the construction of dense genetic linkage maps. The construction of such maps is hampered by the occurrence of even small proportions of typing errors. Simulated annealing is used to obtain the best map according to the optimality criterion:

  2. [MapDraw: a microsoft excel macro for drawing genetic linkage maps based on given genetic linkage data].

    Science.gov (United States)

    Liu, Ren-Hu; Meng, Jin-Ling

    2003-05-01

    MAPMAKER is one of the most widely used computer software package for constructing genetic linkage maps.However, the PC version, MAPMAKER 3.0 for PC, could not draw the genetic linkage maps that its Macintosh version, MAPMAKER 3.0 for Macintosh,was able to do. Especially in recent years, Macintosh computer is much less popular than PC. Most of the geneticists use PC to analyze their genetic linkage data. So a new computer software to draw the same genetic linkage maps on PC as the MAPMAKER for Macintosh to do on Macintosh has been crying for. Microsoft Excel,one component of Microsoft Office package, is one of the most popular software in laboratory data processing. Microsoft Visual Basic for Applications (VBA) is one of the most powerful functions of Microsoft Excel. Using this program language, we can take creative control of Excel, including genetic linkage map construction, automatic data processing and more. In this paper, a Microsoft Excel macro called MapDraw is constructed to draw genetic linkage maps on PC computer based on given genetic linkage data. Use this software,you can freely construct beautiful genetic linkage map in Excel and freely edit and copy it to Word or other application. This software is just an Excel format file. You can freely copy it from ftp://211.69.140.177 or ftp://brassica.hzau.edu.cn and the source code can be found in Excel's Visual Basic Editor.

  3. The first genetic linkage map of Eucommia ulmoides

    Indian Academy of Sciences (India)

    Dawei Wang; Yu Li; Long Li; Yongcheng Wei; Zhouqi Li

    2014-04-01

    In accordance with pseudo-testcross strategy, the first genetic linkage map of Eucommia ulmoides Oliv. was constructed by an F1 population of 122 plants using amplified fragment length polymorphism (AFLP) markers. A total of 22 AFLP primer combinations generated 363 polymorphic markers. We selected 289 markers segregating as 1:1 and used them for constructing the parent-specific linkage maps. Among the candidate markers, 127 markers were placed on the maternal map LF and 108 markers on the paternal map Q1. The maternal map LF spanned 1116.1 cM in 14 linkage groups with a mean map distance of 8.78 cM; the paternal map Q1 spanned 929.6 cM in 12 linkage groups with an average spacing of 8.61 cM. The estimated coverage of the genome through two methods was 78.5 and 73.9% for LF, and 76.8 and 71.2% for Q1, respectively. This map is the first linkage map of E. ulmoides and provides a basis for mapping quantitative-trait loci and breeding applications.

  4. A genetic linkage map for the saltwater crocodile (Crocodylus porosus

    Directory of Open Access Journals (Sweden)

    Lance Stacey L

    2009-07-01

    Full Text Available Abstract Background Genome elucidation is now in high gear for many organisms, and whilst genetic maps have been developed for a broad array of species, surprisingly, no such maps exist for a crocodilian, or indeed any other non-avian member of the Class Reptilia. Genetic linkage maps are essential tools for the mapping and dissection of complex quantitative trait loci (QTL, and in order to permit systematic genome scans for the identification of genes affecting economically important traits in farmed crocodilians, a comprehensive genetic linage map will be necessary. Results A first-generation genetic linkage map for the saltwater crocodile (Crocodylus porosus was constructed using 203 microsatellite markers amplified across a two-generation pedigree comprising ten full-sib families from a commercial population at Darwin Crocodile Farm, Northern Territory, Australia. Linkage analyses identified fourteen linkage groups comprising a total of 180 loci, with 23 loci remaining unlinked. Markers were ordered within linkage groups employing a heuristic approach using CRIMAP v3.0 software. The estimated female and male recombination map lengths were 1824.1 and 319.0 centimorgans (cM respectively, revealing an uncommonly large disparity in recombination map lengths between sexes (ratio of 5.7:1. Conclusion We have generated the first genetic linkage map for a crocodilian, or indeed any other non-avian reptile. The uncommonly large disparity in recombination map lengths confirms previous preliminary evidence of major differences in sex-specific recombination rates in a species that exhibits temperature-dependent sex determination (TSD. However, at this point the reason for this disparity in saltwater crocodiles remains unclear. This map will be a valuable resource for crocodilian researchers, facilitating the systematic genome scans necessary for identifying genes affecting complex traits of economic importance in the crocodile industry. In addition

  5. Genetic Linkage Map of the Edible Basidiomycete Pleurotus ostreatus

    Science.gov (United States)

    Larraya, Luis M.; Pérez, Gúmer; Ritter, Enrique; Pisabarro, Antonio G.; Ramírez, Lucía

    2000-01-01

    We have constructed a genetic linkage map of the edible basidiomycete Pleurotus ostreatus (var. Florida). The map is based on the segregation of 178 random amplified polymorphic DNA and 23 restriction fragment length polymorphism markers; four hydrophobin, two laccase, and two manganese peroxidase genes; both mating type loci; one isozyme locus (est1); the rRNA gene sequence; and a repetitive DNA sequence in a population of 80 sibling monokaryons. The map identifies 11 linkage groups corresponding to the chromosomes of P. ostreatus, and it has a total length of 1,000.7 centimorgans (cM) with an average of 35.1 kbp/cM. The map shows a high correlation (0.76) between physical and genetic chromosome sizes. The number of crossovers observed per chromosome per individual cell is 0.89. This map covers nearly the whole genome of P. ostreatus. PMID:11097904

  6. A genetic map of Peromyscus with chromosomal assignment of linkage groups (a Peromyscus genetic map).

    Science.gov (United States)

    Kenney-Hunt, Jane; Lewandowski, Adrienne; Glenn, Travis C; Glenn, Julie L; Tsyusko, Olga V; O'Neill, Rachel J; Brown, Judy; Ramsdell, Clifton M; Nguyen, Quang; Phan, Tony; Shorter, Kimberly R; Dewey, Michael J; Szalai, Gabor; Vrana, Paul B; Felder, Michael R

    2014-04-01

    The rodent genus Peromyscus is the most numerous and species-rich mammalian group in North America. The naturally occurring diversity within this genus allows opportunities to investigate the genetic basis of adaptation, monogamy, behavioral and physiological phenotypes, growth control, genomic imprinting, and disease processes. Increased genomic resources including a high quality genetic map are needed to capitalize on these opportunities. We produced interspecific hybrids between the prairie deer mouse (P. maniculatus bairdii) and the oldfield mouse (P. polionotus) and scored meiotic recombination events in backcross progeny. A genetic map was constructed by genotyping of backcross progeny at 185 gene-based and 155 microsatellite markers representing all autosomes and the X-chromosome. Comparison of the constructed genetic map with the molecular maps of Mus and Rattus and consideration of previous results from interspecific reciprocal whole chromosome painting allowed most linkage groups to be unambiguously assigned to specific Peromyscus chromosomes. Based on genomic comparisons, this Peromyscus genetic map covers ~83% of the Rattus genome and 79% of the Mus genome. This map supports previous results that the Peromyscus genome is more similar to Rattus than Mus. For example, coverage of the 20 Rattus autosomes and the X-chromosome is accomplished with only 28 segments of the Peromyscus map, but coverage of the 19 Mus autosomes and the X-chromosome requires 40 chromosomal segments of the Peromyscus map. Furthermore, a single Peromyscus linkage group corresponds to about 91% of the rat and only 76% of the mouse X-chromosomes.

  7. A genetic linkage map and comparative mapping of the prairie vole (Microtus ochrogaster genome

    Directory of Open Access Journals (Sweden)

    Young Larry J

    2011-07-01

    Full Text Available Abstract Background The prairie vole (Microtus ochrogaster is an emerging rodent model for investigating the genetics, evolution and molecular mechanisms of social behavior. Though a karyotype for the prairie vole has been reported and low-resolution comparative cytogenetic analyses have been done in this species, other basic genetic resources for this species, such as a genetic linkage map, are lacking. Results Here we report the construction of a genome-wide linkage map of the prairie vole. The linkage map consists of 406 markers that are spaced on average every 7 Mb and span an estimated ~90% of the genome. The sex average length of the linkage map is 1707 cM, which, like other Muroid rodent linkage maps, is on the lower end of the length distribution of linkage maps reported to date for placental mammals. Linkage groups were assigned to 19 out of the 26 prairie vole autosomes as well as the X chromosome. Comparative analyses of the prairie vole linkage map based on the location of 387 Type I markers identified 61 large blocks of synteny with the mouse genome. In addition, the results of the comparative analyses revealed a potential elevated rate of inversions in the prairie vole lineage compared to the laboratory mouse and rat. Conclusions A genetic linkage map of the prairie vole has been constructed and represents the fourth genome-wide high-resolution linkage map reported for Muroid rodents and the first for a member of the Arvicolinae sub-family. This resource will advance studies designed to dissect the genetic basis of a variety of social behaviors and other traits in the prairie vole as well as our understanding of genome evolution in the genus Microtus.

  8. Genetic linkage map and comparative genome analysis for the estuarine Atlantic killifish (Fundulus heteroclitus)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Genetic linkage maps are valuable tools in evolutionary biology; however, their availability for wild populations is extremely limited. Fundulus heteroclitus...

  9. Construction of Genetic Linkage Map and QTL Mapping for Fiber Quality in Upland Cotton

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zheng-sheng

    2008-01-01

    @@ A comprehensive genetic linkage map was constructed using 270 F2:7 recombinant inbred lines from a cross between two upland cotton cultivars Yumian 1 and T586.The linkage map comprised of 604 loci and 57 linkage groups ordered into 25 chromosomes,spanning 3106.9 cM,and approximately accounting for the 69.87~ of the whole cotton genome with an average genetic distance of 5.15 cM between two markers.Based on interval mapping,29 QTLs affecting fiber quality were identified,including 5 QTLs for fiber length,7 QTLs for fiber uniformity,10 QTLs for fiber strength,2 QTLs for fiber elongation,and 5 QTLs for fiber fineness.Seventeen QTLs were mapped on A sub-genome chromosomes,and 12 on D sub-genome.

  10. Genetic linkage maps of Japanese and European pears aligned to the apple consensus map

    NARCIS (Netherlands)

    Yamamoto, T.; Kimura, T.; Saito, T.; Kotobuki, K.; Matsuta, N.; Liebhard, R.; Gessler, C.; Weg, van de W.E.; Hayashi, T.

    2004-01-01

    Genetic linkage maps of the Japanese pear (Pyrus pyrifolia Nakai) cultivar `Housui¿ and the European pear (Pyrus communis L.) cultivar `Bartlett¿ were constructed based on Amplified Fragment Length Polymorphism markers (AFLPs), Simple Sequence Repeat markers (SSRs) (from pear, apple and Prunus),

  11. A genetic linkage map for Tribolium confusum based on random amplified polymorphic DNAs and recombinant inbred lines.

    Science.gov (United States)

    Yezerski, A; Stevens, L; Ametrano, J

    2003-10-01

    Tribolium beetles provide an excellent and easily manipulated model system for the study of genetics. However, despite significant increases in the availability of molecular markers for the study of genetics in recent years, a significant genetic linkage map for these beetles remains undeveloped. We present the first molecular genetic linkage map for Tribolium confusum using random amplified polymorphic DNA markers. The linkage map contains 137 loci mapped on to eight linkage groups totaling 968.5 cM.

  12. Preliminary genetic linkage map of Indian major carp, Labeo rohita (Hamilton 1822) based on microsatellite markers

    Indian Academy of Sciences (India)

    L. Sahoo; A. Patel; B. P. Sahu; S. Mitra; P. K. Meher; K. D. Mahapatra; S. K. Dash; P. Jayasankar; P. Das

    2015-06-01

    Linkage map with wide marker coverage is an essential resource for genetic improvement study for any species. Sex-averaged genetic linkage map of Labeo rohita, popularly known as ‘rohu’, widely cultured in the Indian subcontinent, was developed by placing 68 microsatellite markers generated by a simplified method. The parents and their F1 progeny (92 individuals) were used as segregating populations. The genetic linkage map spans a sex-averaged total length of 1462.2 cM, in 25 linkage groups. The genome length of rohu was estimated to be 3087.9 cM. This genetic linkage map may facilitate systematic searches of the genome to identify genes associated with commercially important characters and marker-assisted selection programmes of this species.

  13. SSR and EST-SSR-based genetic linkage map of cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Sraphet, Supajit; Boonchanawiwat, Athipong; Thanyasiriwat, Thanwanit; Boonseng, Opas; Tabata, Satoshi; Sasamoto, Shigemi; Shirasawa, Kenta; Isobe, Sachiko; Lightfoot, David A; Tangphatsornruang, Sithichoke; Triwitayakorn, Kanokporn

    2011-04-01

    Simple sequence repeat (SSR) markers provide a powerful tool for genetic linkage map construction that can be applied for identification of quantitative trait loci (QTL). In this study, a total of 640 new SSR markers were developed from an enriched genomic DNA library of the cassava variety 'Huay Bong 60' and 1,500 novel expressed sequence tag-simple sequence repeat (EST-SSR) loci were developed from the Genbank database. To construct a genetic linkage map of cassava, a 100 F(1) line mapping population was developed from the cross Huay Bong 60 by 'Hanatee'. Polymorphism screening between the parental lines revealed that 199 SSRs and 168 EST-SSRs were identified as novel polymorphic markers. Combining with previously developed SSRs, we report a linkage map consisted of 510 markers encompassing 1,420.3 cM, distributed on 23 linkage groups with a mean distance between markers of 4.54 cM. Comparison analysis of the SSR order on the cassava linkage map and the cassava genome sequences allowed us to locate 284 scaffolds on the genetic map. Although the number of linkage groups reported here revealed that this F(1) genetic linkage map is not yet a saturated map, it encompassed around 88% of the cassava genome indicating that the map was almost complete. Therefore, sufficient markers now exist to encompass most of the genomes and efficiently map traits in cassava.

  14. Mapping autism risk loci using genetic linkage and chromosomal rearrangements

    Science.gov (United States)

    Szatmari, Peter; Paterson, Andrew; Zwaigenbaum, Lonnie; Roberts, Wendy; Brian, Jessica; Liu, Xiao-Qing; Vincent, John; Skaug, Jennifer; Thompson, Ann; Senman, Lili; Feuk, Lars; Qian, Cheng; Bryson, Susan; Jones, Marshall; Marshall, Christian; Scherer, Stephen; Vieland, Veronica; Bartlett, Christopher; Mangin, La Vonne; Goedken, Rhinda; Segre, Alberto; Pericak-Vance, Margaret; Cuccaro, Michael; Gilbert, John; Wright, Harry; Abramson, Ruth; Betancur, Catalina; Bourgeron, Thomas; Gillberg, Christopher; Leboyer, Marion; Buxbaum, Joseph; Davis, Kenneth; Hollander, Eric; Silverman, Jeremy; Hallmayer, Joachim; Lotspeich, Linda; Sutcliffe, James; Haines, Jonathan; Folstein, Susan; Piven, Joseph; Wassink, Thomas; Sheffield, Val; Geschwind, Daniel; Bucan, Maja; Brown, Ted; Cantor, Rita; Constantino, John; Gilliam, Conrad; Herbert, Martha; Lajonchere, Clara; Ledbetter, David; Lese-Martin, Christa; Miller, Janet; Nelson, Stan; Samango-Sprouse, Carol; Spence, Sarah; State, Matthew; Tanzi, Rudolph; Coon, Hilary; Dawson, Geraldine; Devlin, Bernie; Estes, Annette; Flodman, Pamela; Klei, Lambertus; Mcmahon, William; Minshew, Nancy; Munson, Jeff; Korvatska, Elena; Rodier, Patricia; Schellenberg, Gerard; Smith, Moyra; Spence, Anne; Stodgell, Chris; Tepper, Ping Guo; Wijsman, Ellen; Yu, Chang-En; Rogé, Bernadette; Mantoulan, Carine; Wittemeyer, Kerstin; Poustka, Annemarie; Felder, Bärbel; Klauck, Sabine; Schuster, Claudia; Poustka, Fritz; Bölte, Sven; Feineis-Matthews, Sabine; Herbrecht, Evelyn; Schmötzer, Gabi; Tsiantis, John; Papanikolaou, Katerina; Maestrini, Elena; Bacchelli, Elena; Blasi, Francesca; Carone, Simona; Toma, Claudio; Van Engeland, Herman; De Jonge, Maretha; Kemner, Chantal; Koop, Frederieke; Langemeijer, Marjolein; Hijmans, Channa; Staal, Wouter; Baird, Gillian; Bolton, Patrick; Rutter, Michael; Weisblatt, Emma; Green, Jonathan; Aldred, Catherine; Wilkinson, Julie-Anne; Pickles, Andrew; Le Couteur, Ann; Berney, Tom; Mcconachie, Helen; Bailey, Anthony; Francis, Kostas; Honeyman, Gemma; Hutchinson, Aislinn; Parr, Jeremy; Wallace, Simon; Monaco, Anthony; Barnby, Gabrielle; Kobayashi, Kazuhiro; Lamb, Janine; Sousa, Ines; Sykes, Nuala; Cook, Edwin; Guter, Stephen; Leventhal, Bennett; Salt, Jeff; Lord, Catherine; Corsello, Christina; Hus, Vanessa; Weeks, Daniel; Volkmar, Fred; Tauber, Maïté; Fombonne, Eric; Shih, Andy; Meyer, Kacie

    2007-01-01

    Autism spectrum disorders (ASD) are common, heritable neurodevelopmental conditions. The genetic architecture of ASD is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASD by using Affymetrix 10K single nucleotide polymorphism (SNP) arrays and 1168 families with ≥ 2 affected individuals to perform the largest linkage scan to date, while also analyzing copy number variation (CNV) in these families. Linkage and CNV analyses implicate chromosome 11p12-p13 and neurexins, respectively, amongst other candidate loci. Neurexins team with previously-implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for ASD. PMID:17322880

  15. Genetic linkage mapping in fungi: current state, applications, and future trends.

    Science.gov (United States)

    Foulongne-Oriol, Marie

    2012-08-01

    Genetic mapping is a basic tool for eukaryotic genomic research. Linkage maps provide insights into genome organization and can be used for genetic studies of traits of interest. A genetic linkage map is a suitable support for the anchoring of whole genome sequences. It allows the localization of genes of interest or quantitative trait loci (QTL) and map-based cloning. While genetic mapping has been extensively used in plant or animal models, this discipline is more recent in fungi. The present article reviews the current status of genetic linkage map research in fungal species. The process of linkage mapping is detailed, from the development of mapping populations to the construction of the final linkage map, and illustrated based on practical examples. The range of specific applications in fungi is browsed, such as the mapping of virulence genes in pathogenic species or the mapping of agronomically relevant QTL in cultivated edible mushrooms. Future prospects are finally discussed in the context of the most recent advances in molecular techniques and the release of numerous fungal genome sequences.

  16. QTL IciMapping:Integrated software for genetic linkage map construction and quantitative trait locus mapping in biparental populations

    Institute of Scientific and Technical Information of China (English)

    Lei; Meng; Huihui; Li; Luyan; Zhang; Jiankang; Wang

    2015-01-01

    QTL Ici Mapping is freely available public software capable of building high-density linkage maps and mapping quantitative trait loci(QTL) in biparental populations. Eight functionalities are integrated in this software package:(1) BIN: binning of redundant markers;(2) MAP: construction of linkage maps in biparental populations;(3) CMP: consensus map construction from multiple linkage maps sharing common markers;(4) SDL: mapping of segregation distortion loci;(5) BIP: mapping of additive, dominant, and digenic epistasis genes;(6) MET: QTL-by-environment interaction analysis;(7) CSL: mapping of additive and digenic epistasis genes with chromosome segment substitution lines; and(8) NAM: QTL mapping in NAM populations. Input files can be arranged in plain text, MS Excel 2003, or MS Excel 2007 formats. Output files have the same prefix name as the input but with different extensions. As examples, there are two output files in BIN, one for summarizing the identified bin groups and deleted markers in each bin, and the other for using the MAP functionality. Eight output files are generated by MAP, including summary of the completed linkage maps, Mendelian ratio test of individual markers, estimates of recombination frequencies, LOD scores, and genetic distances, and the input files for using the BIP, SDL,and MET functionalities. More than 30 output files are generated by BIP, including results at all scanning positions, identified QTL, permutation tests, and detection powers for up to six mapping methods. Three supplementary tools have also been developed to display completed genetic linkage maps, to estimate recombination frequency between two loci,and to perform analysis of variance for multi-environmental trials.

  17. QTL IciMapping:Integrated software for genetic linkage map construction and quantitative trait locus mapping in biparental populations

    Institute of Scientific and Technical Information of China (English)

    Lei Meng; Huihui Li; Luyan Zhang; Jiankang Wang

    2015-01-01

    QTL IciMapping is freely available public software capable of building high-density linkage maps and mapping quantitative trait loci (QTL) in biparental populations. Eight func-tionalities are integrated in this software package: (1) BIN:binning of redundant markers;(2) MAP: construction of linkage maps in biparental populations; (3) CMP: consensus map construction from multiple linkage maps sharing common markers; (4) SDL: mapping of segregation distortion loci;(5) BIP:mapping of additive, dominant, and digenic epistasis genes;(6) MET:QTL-by-environment interaction analysis;(7) CSL:mapping of additive and digenic epistasis genes with chromosome segment substitution lines; and (8) NAM: QTL mapping in NAM populations. Input files can be arranged in plain text, MS Excel 2003, or MS Excel 2007 formats. Output files have the same prefix name as the input but with different extensions. As examples, there are two output files in BIN, one for summarizing the identified bin groups and deleted markers in each bin, and the other for using the MAP functionality. Eight output files are generated by MAP, including summary of the completed linkage maps, Mendelian ratio test of individual markers, estimates of recombination frequencies, LOD scores, and genetic distances, and the input files for using the BIP, SDL, and MET functionalities. More than 30 output files are generated by BIP, including results at all scanning positions, identified QTL, permutation tests, and detection powers for up to six mapping methods. Three supplementary tools have also been developed to display completed genetic linkage maps, to estimate recombination frequency between two loci, and to perform analysis of variance for multi-environmental trials.

  18. QTL IciMapping: Integrated software for genetic linkage map construction and quantitative trait locus mapping in biparental populations

    Directory of Open Access Journals (Sweden)

    Lei Meng

    2015-06-01

    Full Text Available QTL IciMapping is freely available public software capable of building high-density linkage maps and mapping quantitative trait loci (QTL in biparental populations. Eight functionalities are integrated in this software package: (1 BIN: binning of redundant markers; (2 MAP: construction of linkage maps in biparental populations; (3 CMP: consensus map construction from multiple linkage maps sharing common markers; (4 SDL: mapping of segregation distortion loci; (5 BIP: mapping of additive, dominant, and digenic epistasis genes; (6 MET: QTL-by-environment interaction analysis; (7 CSL: mapping of additive and digenic epistasis genes with chromosome segment substitution lines; and (8 NAM: QTL mapping in NAM populations. Input files can be arranged in plain text, MS Excel 2003, or MS Excel 2007 formats. Output files have the same prefix name as the input but with different extensions. As examples, there are two output files in BIN, one for summarizing the identified bin groups and deleted markers in each bin, and the other for using the MAP functionality. Eight output files are generated by MAP, including summary of the completed linkage maps, Mendelian ratio test of individual markers, estimates of recombination frequencies, LOD scores, and genetic distances, and the input files for using the BIP, SDL, and MET functionalities. More than 30 output files are generated by BIP, including results at all scanning positions, identified QTL, permutation tests, and detection powers for up to six mapping methods. Three supplementary tools have also been developed to display completed genetic linkage maps, to estimate recombination frequency between two loci, and to perform analysis of variance for multi-environmental trials.

  19. A genetic linkage map of hexaploid naked oat constructed with SSR markers

    Institute of Scientific and Technical Information of China (English)

    Gaoyuan; Song; Pengjie; Huo; Bin; Wu; Zongwen; Zhang

    2015-01-01

    Naked oat is a unique health food crop in China. Using 202 F2 individuals derived from a hybrid between the variety 578 and the landrace Sanfensan, we constructed a genetic linkage map consisting of 22 linkage groups covering 2070.50 c M and including 208 simple sequence repeat(SSR) markers. The minimum distance between adjacent markers was0.01 c M and the average was 9.95 c M. Each linkage group contained 2–22 markers. The largest linkage group covered 174.40 c M and the shortest one covered 36.80 c M, with an average of 94.11 c M. Thirty-six markers(17.3%) showing distorted segregation were distributed across linkage groups LG5 to LG22. This map complements published oat genetic maps and is applicable for quantitative trait locus analysis, gene cloning and molecular marker-assisted selection.

  20. Preliminary genetic linkage maps of Chinese herb Dendrobium nobile and D. moniliforme

    Indian Academy of Sciences (India)

    Shangguo Feng; Hongyan Zhao; Jiangjie Lu; Junjun Liu; Bo Shen; Huizhong Wang

    2013-08-01

    Dendrobium is an endangered genus in the orchid family with medicinal and horticultural value. Two preliminary genetic linkage maps were constructed using 90 F1 progeny individuals derived from an interspecific cross between D. nobile and D. moniliforme (both, $2n = 38$), using random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR). A total of 286 RAPD loci and 68 ISSR loci were identified and used for genetic linkage analysis. Maps were constructed by double pseudo-testcross mapping strategy using the software Mapmaker/EXP ver. 3.0, and Kosambi map distances were constructed using a LOD score ≥4 and a recombination threshold of 0.4. The resulting frame map of D. nobile was 1474 cM in total length with 116 loci distributed in 15 linkage groups; and the D. moniliforme linkage map had 117 loci placed in 16 linkage groups spanning 1326.5 cM. Both maps showed 76.91% and 73.59% genome coverage for D. nobile and D. moniliforme, respectively. These primary maps provide an important basis for genetic studies and further medicinal and horticultural traits mapping and marker-assisted selection in Dendrobium breeding programmes.

  1. Near-saturated and complete genetic linkage map of black spruce (Picea mariana).

    Science.gov (United States)

    Kang, Bum-Yong; Mann, Ishminder K; Major, John E; Rajora, Om P

    2010-09-24

    Genetic maps provide an important genomic resource for understanding genome organization and evolution, comparative genomics, mapping genes and quantitative trait loci, and associating genomic segments with phenotypic traits. Spruce (Picea) genomics work is quite challenging, mainly because of extremely large size and highly repetitive nature of its genome, unsequenced and poorly understood genome, and the general lack of advanced-generation pedigrees. Our goal was to construct a high-density genetic linkage map of black spruce (Picea mariana, 2n = 24), which is a predominant, transcontinental species of the North American boreal and temperate forests, with high ecological and economic importance. We have developed a near-saturated and complete genetic linkage map of black spruce using a three-generation outbred pedigree and amplified fragment length polymorphism (AFLP), selectively amplified microsatellite polymorphic loci (SAMPL), expressed sequence tag polymorphism (ESTP), and microsatellite (mostly cDNA based) markers. Maternal, paternal, and consensus genetic linkage maps were constructed. The maternal, paternal, and consensus maps in our study consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n = 1x = 12) of 12 in the genus Picea. The maternal map had 816 and the paternal map 743 markers distributed over 12 linkage groups each. The consensus map consisted of 1,111 markers distributed over 12 linkage groups, and covered almost the entire (> 97%) black spruce genome. The mapped markers included 809 AFLPs, 255 SAMPL, 42 microsatellites, and 5 ESTPs. Total estimated length of the genetic map was 1,770 cM, with an average of one marker every 1.6 cM. The maternal, paternal and consensus genetic maps aligned almost perfectly. We have constructed the first high density to near-saturated genetic linkage map of black spruce, with greater than 97% genome coverage. Also, this is the first genetic map based on a three

  2. Near-saturated and complete genetic linkage map of black spruce (Picea mariana

    Directory of Open Access Journals (Sweden)

    Mann Ishminder K

    2010-09-01

    Full Text Available Abstract Background Genetic maps provide an important genomic resource for understanding genome organization and evolution, comparative genomics, mapping genes and quantitative trait loci, and associating genomic segments with phenotypic traits. Spruce (Picea genomics work is quite challenging, mainly because of extremely large size and highly repetitive nature of its genome, unsequenced and poorly understood genome, and the general lack of advanced-generation pedigrees. Our goal was to construct a high-density genetic linkage map of black spruce (Picea mariana, 2n = 24, which is a predominant, transcontinental species of the North American boreal and temperate forests, with high ecological and economic importance. Results We have developed a near-saturated and complete genetic linkage map of black spruce using a three-generation outbred pedigree and amplified fragment length polymorphism (AFLP, selectively amplified microsatellite polymorphic loci (SAMPL, expressed sequence tag polymorphism (ESTP, and microsatellite (mostly cDNA based markers. Maternal, paternal, and consensus genetic linkage maps were constructed. The maternal, paternal, and consensus maps in our study consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n = 1x = 12 of 12 in the genus Picea. The maternal map had 816 and the paternal map 743 markers distributed over 12 linkage groups each. The consensus map consisted of 1,111 markers distributed over 12 linkage groups, and covered almost the entire (> 97% black spruce genome. The mapped markers included 809 AFLPs, 255 SAMPL, 42 microsatellites, and 5 ESTPs. Total estimated length of the genetic map was 1,770 cM, with an average of one marker every 1.6 cM. The maternal, paternal and consensus genetic maps aligned almost perfectly. Conclusion We have constructed the first high density to near-saturated genetic linkage map of black spruce, with greater than 97% genome coverage. Also, this

  3. High-Density Genetic Linkage Map Construction and Quantitative Trait Locus Mapping for Hawthorn (Crataegus pinnatifida Bunge).

    Science.gov (United States)

    Zhao, Yuhui; Su, Kai; Wang, Gang; Zhang, Liping; Zhang, Jijun; Li, Junpeng; Guo, Yinshan

    2017-07-14

    Genetic linkage maps are an important tool in genetic and genomic research. In this study, two hawthorn cultivars, Qiujinxing and Damianqiu, and 107 progenies from a cross between them were used for constructing a high-density genetic linkage map using the 2b-restriction site-associated DNA (2b-RAD) sequencing method, as well as for mapping quantitative trait loci (QTL) for flavonoid content. In total, 206,411,693 single-end reads were obtained, with an average sequencing depth of 57× in the parents and 23× in the progeny. After quality trimming, 117,896 high-quality 2b-RAD tags were retained, of which 42,279 were polymorphic; of these, 12,951 markers were used for constructing the genetic linkage map. The map contained 17 linkage groups and 3,894 markers, with a total map length of 1,551.97 cM and an average marker interval of 0.40 cM. QTL mapping identified 21 QTLs associated with flavonoid content in 10 linkage groups, which explained 16.30-59.00% of the variance. This is the first high-density linkage map for hawthorn, which will serve as a basis for fine-scale QTL mapping and marker-assisted selection of important traits in hawthorn germplasm and will facilitate chromosome assignment for hawthorn whole-genome assemblies in the future.

  4. Genetic linkage map of Brassica campestris L. Using AFLP and RAPD markers

    Institute of Scientific and Technical Information of China (English)

    卢钢; 曹家树; 陈杭

    2002-01-01

    A genetic linkage map comprised of 131 loci was constructed with an F2 population derived from an inter-subspecific cross between Brassica 'qisihai'. The genetic map included 93 RAPD loci, 36 AFLP loci and 2 morphological loci organized into 10 main linkage groups (LGs) and 2 small groups, covering 1810.9cM with average distance between adjacent markers being approximately 13.8cM. The map is suitable for identification of molecular markers linked to important agronomic traits, QTL analysis, and even for marker-assisted selection in breeding programs of Chinese cabbage and turnip.

  5. A genetic linkage map of Venturia inaequalis, the causal agent of apple scab

    Directory of Open Access Journals (Sweden)

    Harvey Nick G

    2009-08-01

    Full Text Available Abstract Background Venturia inaequalis is an economically-important disease of apple causing annual epidemics of scab worldwide. The pathogen is a heterothallic ascomycete with an annual cycle of sexual reproduction on infected apple leaf litter, followed by several cycles of asexual reproduction during the apple growing season. Current disease control is achieved mainly through scheduled applications of fungicides. Genetic linkage maps are essential for studying genome structure and organisation, and are a valuable tool for identifying the location of genes controlling important traits of interest such as avirulence, host specificity and mating type in V. inaequalis. In this study, we performed a wide cross under in vitro conditions between an isolate of V. inaequalis from China and one from the UK to obtain a genetically diverse mapping population of ascospore progeny isolates and produced a map using AFLP and microsatellite (SSR markers. Findings Eighty-three progeny were obtained from the cross between isolates C0154 (China × 01/213 (UK. The progeny was screened with 18 AFLP primer combinations and 31 SSRs, and scored for the mating type locus MAT. A linkage map was constructed consisting of 294 markers (283 AFLPs, ten SSRs and the MAT locus, spanning eleven linkage groups and with a total map length of 1106 cM. The length of individual linkage groups ranged from 30.4 cM (Vi-11 to 166 cM (Vi-1. The number of molecular markers per linkage group ranged from 7 on Vi-11 to 48 on Vi-3; the average distance between two loci within each group varied from 2.4 cM (Vi-4 to 7.5 cM (Vi-9. The maximum map length between two markers within a linkage group was 15.8 cM. The MAT locus was mapped to a small linkage group and was tightly linked to two AFLP markers. The map presented is over four times longer than the previously published map of V. inaequalis which had a total genetic distance of just 270 cM. Conclusion A genetic linkage map is an important

  6. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    DEFF Research Database (Denmark)

    Tomaszewski, Céline; Byrne, Stephen; Foito, Alexandra;

    2012-01-01

    T markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used...

  7. A second-generation anchored genetic linkage map of the tammar wallaby (Macropus eugenii

    Directory of Open Access Journals (Sweden)

    Patel Hardip R

    2011-08-01

    Full Text Available Abstract Background The tammar wallaby, Macropus eugenii, a small kangaroo used for decades for studies of reproduction and metabolism, is the model Australian marsupial for genome sequencing and genetic investigations. The production of a more comprehensive cytogenetically-anchored genetic linkage map will significantly contribute to the deciphering of the tammar wallaby genome. It has great value as a resource to identify novel genes and for comparative studies, and is vital for the ongoing genome sequence assembly and gene ordering in this species. Results A second-generation anchored tammar wallaby genetic linkage map has been constructed based on a total of 148 loci. The linkage map contains the original 64 loci included in the first-generation map, plus an additional 84 microsatellite loci that were chosen specifically to increase coverage and assist with the anchoring and orientation of linkage groups to chromosomes. These additional loci were derived from (a sequenced BAC clones that had been previously mapped to tammar wallaby chromosomes by fluorescence in situ hybridization (FISH, (b End sequence from BACs subsequently FISH-mapped to tammar wallaby chromosomes, and (c tammar wallaby genes orthologous to opossum genes predicted to fill gaps in the tammar wallaby linkage map as well as three X-linked markers from a published study. Based on these 148 loci, eight linkage groups were formed. These linkage groups were assigned (via FISH-mapped markers to all seven autosomes and the X chromosome. The sex-pooled map size is 1402.4 cM, which is estimated to provide 82.6% total coverage of the genome, with an average interval distance of 10.9 cM between adjacent markers. The overall ratio of female/male map length is 0.84, which is comparable to the ratio of 0.78 obtained for the first-generation map. Conclusions Construction of this second-generation genetic linkage map is a significant step towards complete coverage of the tammar wallaby

  8. Construction of Genetic Linkage Map Based on SSR Markers in Peanut(Arachis hypogaea L.)

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Molecular genetic maps of crop species can be used in a variety of ways in breeding and genomic research such as identification and mapping of genes and quantitative trait loci (QTLs) for morphological, physiological and economic traits of crop species. However, a comprehensive genetic linkage map for cultivated peanut has not yet been developed due to the extremely low frequency of DNA polymorphism in cultivated peanut. In this study, 142 recombinant inbred lines (RILs) derived from a cross between Yueyou 13 and Zhenzhuhei were used as mapping population in peanut (Arachis hypogaea L.). A total 652 pairs of genomic-SSR primer and 392 pairs of EST-SSR primer were used to detect the polymorphisms between the two parents. 141 SSR primer pairs, 127 genomic-SSR and 14 EST-SSR ones, which can be used to detect polymorphisms between the two parents, were selected to analyze the RILs population. Thus, a linkage genetic map which consists of 131 SSR loci in 20 linkage groups, with a coverage of 679 cM and an average of 6.12 cM of inter-maker distance was constructed. The putative functions of 12 EST-SSR markers located on the map were analyzed. Eleven showed homology to gene sequences deposited in GenBank. This is the first report of construction of a comprehensive genetic map with SSR markers in peanut (Arachis hypogaea L.). The map presented here will provide a genetic framework for mapping the qualitative and quantitative trait in peanut.

  9. Genetic Mapping in Xenopus Laevis: Eight Linkage Groups Established

    OpenAIRE

    Graf, J. D.

    1989-01-01

    Inheritance of alleles at 29 electrophoretically detected protein loci and one pigment locus (albinism) was analyzed in Xenopus laevis by backcrossing multiply heterozygous individuals generated by intersubspecies hybridization. Pairwise linkage tests revealed eight classical linkage groups. These groups have been provisionally numbered from 1 to 8 in an arbitrarily chosen order. Linkage group 1 includes ALB-2 (albumin), ADH-1 (alcohol dehydrogenase), NP (nucleoside phosphorylase), and a(p) (...

  10. Cosmopolitan linkage disequilibrium maps

    Directory of Open Access Journals (Sweden)

    Gibson Jane

    2005-03-01

    Full Text Available Abstract Linkage maps have been invaluable for the positional cloning of many genes involved in severe human diseases. Standard genetic linkage maps have been constructed for this purpose from the Centre d'Etude du Polymorphisme Humain and other panels, and have been widely used. Now that attention has shifted towards identifying genes predisposing to common disorders using linkage disequilibrium (LD and maps of single nucleotide polymorphisms (SNPs, it is of interest to consider a standard LD map which is somewhat analogous to the corresponding map for linkage. We have constructed and evaluated a cosmopolitan LD map by combining samples from a small number of populations using published data from a 10-megabase region on chromosome 20. In support of a pilot study, which examined a number of small genomic regions with a lower density of markers, we have found that a cosmopolitan map, which serves all populations when appropriately scaled, recovers 91 to 95 per cent of the information within population-specific maps. Recombination hot spots appear to have a dominant role in shaping patterns of LD. The success of the cosmopolitan map might be attributed to the co-localisation of hot spots in all populations. Although there must be finer scale differences between populations due to other processes (mutation, drift, selection, the results suggest that a whole-genome standard LD map would indeed be a useful resource for disease gene mapping.

  11. A dense genetic linkage map for common carp and its integration with a BAC-based physical map.

    Directory of Open Access Journals (Sweden)

    Lan Zhao

    Full Text Available BACKGROUND: Common carp (Cyprinus carpio is one of the most important aquaculture species with an annual global production of 3.4 million metric tons. It is also an important ornamental species as well as an important model species for aquaculture research. To improve the economically important traits of this fish, a number of genomic resources and genetic tools have been developed, including several genetic maps and a bacterial artificial chromosome (BAC-based physical map. However, integrated genetic and physical maps are not available to study quantitative trait loci (QTL and assist with fine mapping, positional cloning and whole genome sequencing and assembly. The objective of this study was to integrate the currently available BAC-based physical and genetic maps. RESULTS: The genetic map was updated with 592 novel markers, including 312 BAC-anchored microsatellites and 130 SNP markers, and contained 1,209 genetic markers on 50 linkage groups, spanning 3,565.9 cM in the common carp genome. An integrated genetic and physical map of the common carp genome was then constructed, which was composed of 463 physical map contigs and 88 single BACs. Combined lengths of the contigs and single BACs covered a physical length of 498.75 Mb, or around 30% of the common carp genome. Comparative analysis between common carp and zebrafish genomes was performed based on the integrated map, providing more insights into the common carp specific whole genome duplication and segmental rearrangements in the genome. CONCLUSION: We integrated a BAC-based physical map to a genetic linkage map of common carp by anchoring BAC-associated genetic markers. The density of the genetic linkage map was significantly increased. The integrated map provides a tool for both genetic and genomic studies of common carp, which will help us to understand the genomic architecture of common carp and facilitate fine mapping and positional cloning of economically important traits for

  12. A SSR-based composite genetic linkage map for the cultivated peanut (Arachis hypogaea L. genome

    Directory of Open Access Journals (Sweden)

    Li Shaoxiong

    2010-01-01

    Full Text Available Abstract Background The construction of genetic linkage maps for cultivated peanut (Arachis hypogaea L. has and continues to be an important research goal to facilitate quantitative trait locus (QTL analysis and gene tagging for use in a marker-assisted selection in breeding. Even though a few maps have been developed, they were constructed using diploid or interspecific tetraploid populations. The most recently published intra-specific map was constructed from the cross of cultivated peanuts, in which only 135 simple sequence repeat (SSR markers were sparsely populated in 22 linkage groups. The more detailed linkage map with sufficient markers is necessary to be feasible for QTL identification and marker-assisted selection. The objective of this study was to construct a genetic linkage map of cultivated peanut using simple sequence repeat (SSR markers derived primarily from peanut genomic sequences, expressed sequence tags (ESTs, and by "data mining" sequences released in GenBank. Results Three recombinant inbred lines (RILs populations were constructed from three crosses with one common female parental line Yueyou 13, a high yielding Spanish market type. The four parents were screened with 1044 primer pairs designed to amplify SSRs and 901 primer pairs produced clear PCR products. Of the 901 primer pairs, 146, 124 and 64 primer pairs (markers were polymorphic in these populations, respectively, and used in genotyping these RIL populations. Individual linkage maps were constructed from each of the three populations and a composite map based on 93 common loci were created using JoinMap. The composite linkage maps consist of 22 composite linkage groups (LG with 175 SSR markers (including 47 SSRs on the published AA genome maps, representing the 20 chromosomes of A. hypogaea. The total composite map length is 885.4 cM, with an average marker density of 5.8 cM. Segregation distortion in the 3 populations was 23.0%, 13.5% and 7.8% of the markers

  13. SSR-based genetic linkage map of Cucurbita moschata and its synteny with Cucurbita pepo.

    Science.gov (United States)

    Gong, L; Pachner, M; Kalai, K; Lelley, T

    2008-11-01

    The first SSR-based genetic linkage map of Cucurbita moschata was created by integrating the maps of two F2 populations with one common parent developed from the crosses Waltham Butternut (WB) x Nigerian Local (NL) and ZHOU (a hull-less type) x WB. The integrated C. moschata map comprises 205 SSR markers and two morphological traits (Gr and n). The map is composed of 27 linkage groups with a marker density of 7 cM. Comparing the C. moschata map with the published Cucurbita pepo map, we found a high level of macrosynteny. Seventy-two of 76 common SSR markers between C. moschata and C. pepo were located in homologous linkage groups. These markers in general have conserved orders and similar genetic distances; they represent orthologous loci. A reference map based on these SSRs was obtained. No major chromosomal rearrangement between the two species could be detected at present, although four SSR markers were mapped in nonhomologous linkage groups. The comparative alignment of SSR markers did not provide any indication of a possible ancient polyploid origin of the species. The comparative mapping of C. moschata and C. pepo reported here will be useful for further studies on Cucurbit evolution, gene isolation, and breeding work.

  14. An integrated genetic linkage map for white clover (Trifolium repens L.) with alignment to Medicago

    Science.gov (United States)

    2013-01-01

    Background White clover (Trifolium repens L.) is a temperate forage legume with an allotetraploid genome (2n=4×=32) estimated at 1093 Mb. Several linkage maps of various sizes, marker sources and completeness are available, however, no integrated map and marker set has explored consistency of linkage analysis among unrelated mapping populations. Such integrative analysis requires tools for homoeologue matching among populations. Development of these tools provides for a consistent framework map of the white clover genome, and facilitates in silico alignment with the model forage legume, Medicago truncatula. Results This is the first report of integration of independent linkage maps in white clover, and adds to the literature on methyl filtered GeneThresher®-derived microsatellite (simple sequence repeat; SSR) markers for linkage mapping. Gene-targeted SSR markers were discovered in a GeneThresher® (TrGT) methyl-filtered database of 364,539 sequences, which yielded 15,647 SSR arrays. Primers were designed for 4,038 arrays and of these, 465 TrGT-SSR markers were used for parental consensus genetic linkage analysis in an F1 mapping population (MP2). This was merged with an EST-SSR consensus genetic map of an independent population (MP1), using markers to match homoeologues and develop a multi-population integrated map of the white clover genome. This integrated map (IM) includes 1109 loci based on 804 SSRs over 1274 cM, covering 97% of the genome at a moderate density of one locus per 1.2 cM. Eighteen candidate genes and one morphological marker were also placed on the IM. Despite being derived from disparate populations and marker sources, the component maps and the derived IM had consistent representations of the white clover genome for marker order and genetic length. In silico analysis at an E-value threshold of 1e-20 revealed substantial co-linearity with the Medicago truncatula genome, and indicates a translocation between T. repens groups 2 and 6 relative to

  15. Second generation genetic linkage map for the gilthead sea bream Sparus aurata L.

    Science.gov (United States)

    Tsigenopoulos, Costas S; Louro, Bruno; Chatziplis, Dimitrios; Lagnel, Jacques; Vogiatzi, Emmanouella; Loukovitis, Dimitrios; Franch, Rafaella; Sarropoulou, Elena; Power, Deborah M; Patarnello, Tomaso; Mylonas, Constantinos C; Magoulas, Antonios; Bargelloni, Luca; Canario, Adelino; Kotoulas, Georgios

    2014-12-01

    An updated second linkage map was constructed for the gilthead sea bream, Sparus aurata L., a fish species of great economic importance for the Mediterranean aquaculture industry. In contrast to the first linkage map which mainly consisted of genomic microsatellites (SSRs), the new linkage map is highly enriched with SSRs found in Expressed Sequence Tags (EST-SSRs), which greatly facilitates comparative mapping with other teleosts. The new map consists of 321 genetic markers in 27 linkage groups (LGs): 232 genomic microsatellites, 85 EST-SSRs and 4 SNPs; of those, 13 markers were linked to LGs but were not ordered. Eleven markers (5 SSRs, 5 EST-SSRs and 1 SNP) are not assigned to any LG. The total length of the sex-averaged map is 1769.7cM, 42% longer than the previously published one, and the number of markers in each LG ranges from 2 to 30. The inter-marker distance varies from 0 to 75.6cM, with an average of 5.75cM. The male and female maps have a length of 1349.2 and 2172.1cM, respectively, and the average distance between markers is 4.38 and 7.05cM, respectively. Comparative mapping with the three-spined stickleback (Gasterosteus acuulatus) chromosomes and scaffolds showed conserved synteny with 132 S. aurata markers (42.9% of those mapped) having a hit on the stickleback genome.

  16. A genetic linkage map of quinoa ( Chenopodium quinoa) based on AFLP, RAPD, and SSR markers.

    Science.gov (United States)

    Maughan, P J; Bonifacio, A; Jellen, E N; Stevens, M R; Coleman, C E; Ricks, M; Mason, S L; Jarvis, D E; Gardunia, B W; Fairbanks, D J

    2004-10-01

    Quinoa ( Chenopodium quinoa Willd.) is an important seed crop for human consumption in the Andean region of South America. It is the primary staple in areas too arid or saline for the major cereal crops. The objective of this project was to build the first genetic linkage map of quinoa. Selection of the mapping population was based on a preliminary genetic similarity analysis of four potential mapping parents. Breeding lines 'Ku-2' and '0654', a Chilean lowland type and a Peruvian Altiplano type, respectively, showed a low similarity coefficient of 0.31 and were selected to form an F(2) mapping population. The genetic map is based on 80 F(2) individuals from this population and consists of 230 amplified length polymorphism (AFLP), 19 simple-sequence repeat (SSR), and six randomly amplified polymorphic DNA markers. The map spans 1,020 cM and contains 35 linkage groups with an average marker density of 4.0 cM per marker. Clustering of AFLP markers was not observed. Additionally, we report the primer sequences and map locations for 19 SSR markers that will be valuable tools for future quinoa genome analysis. This map provides a key starting point for genetic dissection of agronomically important characteristics of quinoa, including seed saponin content, grain yield, maturity, and resistance to disease, frost, and drought. Current efforts are geared towards the generation of more than 200 mapped SSR markers and the development of several recombinant-inbred mapping populations.

  17. Construction of a genetic linkage map in Lilium using a RIL mapping population based on SRAP marker

    Directory of Open Access Journals (Sweden)

    Chen Li-Jing

    2015-01-01

    Full Text Available A genetic linkage map of lily was constructed using RILs (recombinant inbred lines population of 180 individuals. This mapping population was developed by crossing Raizan No.1 (Formolongo and Gelria (Longiflomm cultivars through single-seed descent (SSD. SRAPs were generated by using restriction enzymes EcoRI in combination with either MseI. The resulting products were separated by electrophoresis on 6% denaturing polyacrylamide gel and visualized by silver staining. The segregation of each marker and linkage analysis was done using the program Mapmaker3.0. With 50 primer pairs, a total of 189 parental polymorphic bands were detected and 78 were used for mapping. The total map length was 2,135.5 cM consisted of 16 linkage groups. The number of markers in the linkage groups varied from 1 to 12. The length of linkage groups was range from 11.2 cM to 425.9 cM and mean marker interval distance range from 9.4 cM to 345.4 cM individually. The mean marker interval distance between markers was 27.4 cM. The map developed in the present study was the first sequence-related amplified polymorphism markers map of lily constructed with recombinant inbred lines, it could be used for genetic mapping and molecular marker assisted breeding and quantitative trait locus mapping of Lilium.

  18. Genetic linkage maps of Pinus koraiensis Sieb. et Zucc. based on ...

    African Journals Online (AJOL)

    USER

    2010-08-30

    Aug 30, 2010 ... Genetic linkage maps provide essential information for molecular breeding. ... to plants are: (1) basic knowledge of genomic structure, ... quantitative trait expression. ... 11. A-6. GAA. CTC. 126. 27. 20. A-7. GAA. CTG. 113. 19. 13. A-3 .... combinations) code (the first three letters correspond to the selective ...

  19. Record: a novel method for ordering loci on a genetic linkage map

    NARCIS (Netherlands)

    Os, van H.; Stam, P.; Visser, R.G.F.; Eck, van H.J.

    2005-01-01

    A new method, REcombination Counting and ORDering (RECORD) is presented for the ordering of loci on genetic linkage maps. The method minimizes the total number of recombination events. The search algorithm is a heuristic procedure, combining elements of branch-and-bound with local reshuffling. Since

  20. Simple Sequence Repeat Genetic Linkage Maps of A-genome Diploid Cotton (Gossypium arboreum)

    Institute of Scientific and Technical Information of China (English)

    Xue-Xia Ma; Bao-Liang Zhou; Yan-Hui Lü; Wang-Zhen Guo; Tian-Zhen Zhang

    2008-01-01

    This study introduces the construction of the first intraspacific genetic linkage map of the A-genome diploid cotton with newly developed simple sequence repeat (SSR) markers using 189 F2 plants derived from the cross of two Asiatic parents were detected using 6 092 pairs of SSR primers. Two-hundred and sixty-eight pairs of SSR pdmers with better polymorphisms were picked out to analyze the F2 population. In total, 320 polymorphic bands were generated and used to construct a linkage map with JoinMap3.0. Two-hundred and sixty-seven loci, Including three phenotypic traits were mapped at a logarithms of odds ratio (LOD) ≥ 3.0 on 13 linkage groups. The total length of the map was 2 508.71 cM, and the average distance between adjacent markers was 9.40 cM. Chromosome assignments were according to the association of linkages with our backbone tetraploid specific map using the 89 similar SSR loci. Comparisons among the 13 suites of orthologous linkage groups revealed that the A-genome chromosomes are largely collinear with the At and Dt sub-genome chromosomes. Chromosomes associated with inversions suggested that allopolyploidization was accompanied by homologous chromosomal rearrangement. The inter-chromosomal duplicated loci supply molecular evidence that the A-genome diploid Asiatic cotton is paleopolyploid.

  1. Efficient and accurate construction of genetic linkage maps from the minimum spanning tree of a graph.

    Directory of Open Access Journals (Sweden)

    Yonghui Wu

    2008-10-01

    Full Text Available Genetic linkage maps are cornerstones of a wide spectrum of biotechnology applications, including map-assisted breeding, association genetics, and map-assisted gene cloning. During the past several years, the adoption of high-throughput genotyping technologies has been paralleled by a substantial increase in the density and diversity of genetic markers. New genetic mapping algorithms are needed in order to efficiently process these large datasets and accurately construct high-density genetic maps. In this paper, we introduce a novel algorithm to order markers on a genetic linkage map. Our method is based on a simple yet fundamental mathematical property that we prove under rather general assumptions. The validity of this property allows one to determine efficiently the correct order of markers by computing the minimum spanning tree of an associated graph. Our empirical studies obtained on genotyping data for three mapping populations of barley (Hordeum vulgare, as well as extensive simulations on synthetic data, show that our algorithm consistently outperforms the best available methods in the literature, particularly when the input data are noisy or incomplete. The software implementing our algorithm is available in the public domain as a web tool under the name MSTmap.

  2. Dissecting the Genetics of Complex Inheritance: Linkage Disequilibrium Mapping Provides Insight into Crohn Disease

    OpenAIRE

    Elding, Heather; Lau, Winston; Swallow, Dallas M.; Maniatis, Nikolas

    2011-01-01

    Family studies for Crohn disease (CD) report extensive linkage on chromosome 16q and pinpoint NOD2 as a possible causative locus. However, linkage is also observed in families that do not bear the most frequent NOD2 causative mutations, but no other signals on 16q have been found so far in published genome-wide association studies. Our aim is to identify this missing genetic contribution. We apply a powerful genetic mapping approach to the Wellcome Trust Case-Control Consortium and the Nation...

  3. An ultra-dense SNP linkage map for the octoploid, cultivated strawberry and its application in genetic research

    Science.gov (United States)

    We will present an ultra-dense genetic linkage map for the octoploid, cultivated strawberry (Fragaria x ananassa) consisting of over 13K Axiom® based SNP markers and 150 previously mapped reference SSR loci. The high quality of the map is demonstrated by the short sizes of each of the 28 linkage gro...

  4. Annotated genetic linkage maps of Pinus pinaster Ait. from a Central Spain population using microsatellite and gene based markers

    Directory of Open Access Journals (Sweden)

    de Miguel Marina

    2012-10-01

    Full Text Available Abstract Background Pinus pinaster Ait. is a major resin producing species in Spain. Genetic linkage mapping can facilitate marker-assisted selection (MAS through the identification of Quantitative Trait Loci and selection of allelic variants of interest in breeding populations. In this study, we report annotated genetic linkage maps for two individuals (C14 and C15 belonging to a breeding program aiming to increase resin production. We use different types of DNA markers, including last-generation molecular markers. Results We obtained 13 and 14 linkage groups for C14 and C15 maps, respectively. A total of 211 and 215 markers were positioned on each map and estimated genome length was between 1,870 and 2,166 cM respectively, which represents near 65% of genome coverage. Comparative mapping with previously developed genetic linkage maps for P. pinaster based on about 60 common markers enabled aligning linkage groups to this reference map. The comparison of our annotated linkage maps and linkage maps reporting QTL information revealed 11 annotated SNPs in candidate genes that co-localized with previously reported QTLs for wood properties and water use efficiency. Conclusions This study provides genetic linkage maps from a Spanish population that shows high levels of genetic divergence with French populations from which segregating progenies have been previously mapped. These genetic maps will be of interest to construct a reliable consensus linkage map for the species. The importance of developing functional genetic linkage maps is highlighted, especially when working with breeding populations for its future application in MAS for traits of interest.

  5. SSR genetic linkage map construction of pea(Pisum sativum L.) based on Chinese native varieties

    Institute of Scientific and Technical Information of China (English)

    Xuelian; Sun; Tao; Yang; Junjie; Hao; Xiaoyan; Zhang; Rebecca; Ford; Junye; Jiang; Fang; Wang; Jianping; Guan; Xuxiao; Zong

    2014-01-01

    Simple sequence repeat(SSR)markers have previously been applied to linkage mapping of the pea(Pisum sativum L.)genome.However,the transferability of existing loci to the molecularly distinct Chinese winter pea gene pool was limited.A novel set of pea SSR markers was accordingly developed.Together with existing SSR sequences,the genome of the G0003973(winter hardy)×G0005527(cold sensitive)cross was mapped using 190 F2individuals.In total,157 SSR markers were placed in 11 linkage groups with an average interval of 9.7 cM and total coverage of 1518 cM.The novel markers and genetic linkage map will be useful for marker-assisted pea breeding.

  6. Construction of a genetic linkage map for cotton based on SRAP

    Institute of Scientific and Technical Information of China (English)

    LIN Zhongxu; ZHANG Xianlong; NIE Yichun; HE Daohua; WU Maoqing

    2003-01-01

    A genetic linkage map of cotton was con structed with a newly developed molecular marker-SRAP (sequence-related amplified polymorphism) using a population consisting of 129 F2 individuals derived from the interspecific cross of "Handan208" x "Pima90". A total of 136 primer pairs were used to detect polymorphisms between the two parents and 76 primer pairs with better polymorphisms were picked out to analyze the F2 population.285 polymorphic bands were generated in total with an average of 3.75 polymorphic bands per pair of primers. The primer pair showing most polymorphic bands was the combination of me3 and em2, which produced 13 polymorphic bands. The 285 loci were used to construct linkage map with MAPMAKER/EXP3.0 and 237 loci were mapped at a LOD≥3.0 on 39 linkage groups. The total length of the map is 3030.7 cM, covering 65.4% of the whole cotton genome, and the average distance between adjacent markers is 12.79 cM. All the markers are distributed evenly among the linkage groups without clustering of loci. This is the first linkage map of cotton comprised of SRAP markers.

  7. Construction of genetic linkage map of the medicinal and ornamental plant Catharanthus roseus

    Indian Academy of Sciences (India)

    Sarika Gupta; Sashi Pandey-Rai; Suchi Srivastava; Subhas Chandra Naithani; Manoj Prasad; Sushil Kumar

    2007-12-01

    An integrated genetic linkage map of the medicinal and ornamental plant Catharanthus roseus, based on different types of molecular and morphological markers was constructed, using a F2 population of 144 plants. The map defines 14 linkage groups (LGs) and consists of 131 marker loci, including 125 molecular DNA markers (76 RAPD, 3 RAPD combinations; 7 ISSR; 2 EST-SSR from Medicago truncatula and 37 other PCR based DNA markers), selected from a total of 472 primers or primer pairs, and six morphological markers (stem pigmentation, leaf lamina pigmentation and shape, leaf petiole and pod size, and petal colour). The total map length is 1131.9 cM (centiMorgans), giving an average map length and distance between two markers equal to 80.9 cM and 8.6 cM, respectively. The morphological markers/genes were found linked with nearest molecular or morphological markers at distances varying from 0.7 to 11.4 cM. Linkage was observed between the morphological markers concerned with lamina shape and petiole size of leaf on LG1 and leaf, stem and petiole pigmentation and pod size on LG8. This is the first genetic linkage map of C. roseus.

  8. An EST-derived SNP and SSR genetic linkage map of cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Rabbi, Ismail Yusuf; Kulembeka, Heneriko Philbert; Masumba, Esther; Marri, Pradeep Reddy; Ferguson, Morag

    2012-07-01

    Cassava (Manihot esculenta Crantz) is one of the most important food security crops in the tropics and increasingly being adopted for agro-industrial processing. Genetic improvement of cassava can be enhanced through marker-assisted breeding. For this, appropriate genomic tools are required to dissect the genetic architecture of economically important traits. Here, a genome-wide SNP-based genetic map of cassava anchored in SSRs is presented. An outbreeder full-sib (F1) family was genotyped on two independent SNP assay platforms: an array of 1,536 SNPs on Illumina's GoldenGate platform was used to genotype a first batch of 60 F1. Of the 1,358 successfully converted SNPs, 600 which were polymorphic in at least one of the parents and was subsequently converted to KBiosciences' KASPar assay platform for genotyping 70 additional F1. High-precision genotyping of 163 informative SSRs using capillary electrophoresis was also carried out. Linkage analysis resulted in a final linkage map of 1,837 centi-Morgans (cM) containing 568 markers (434 SNPs and 134 SSRs) distributed across 19 linkage groups. The average distance between adjacent markers was 3.4 cM. About 94.2% of the mapped SNPs and SSRs have also been localized on scaffolds of version 4.1 assembly of the cassava draft genome sequence. This more saturated genetic linkage map of cassava that combines SSR and SNP markers should find several applications in the improvement of cassava including aligning scaffolds of the cassava genome sequence, genetic analyses of important agro-morphological traits, studying the linkage disequilibrium landscape and comparative genomics.

  9. Construction of the High-Density Genetic Linkage Map and Chromosome Map of Large Yellow Croaker (Larimichthys crocea

    Directory of Open Access Journals (Sweden)

    Jingqun Ao

    2015-11-01

    Full Text Available High-density genetic maps are essential for genome assembly, comparative genomic analysis and fine mapping of complex traits. In this study, 31,191 single nucleotide polymorphisms (SNPs evenly distributed across the large yellow croaker (Larimichthys crocea genome were identified using restriction-site associated DNA sequencing (RAD-seq. Among them, 10,150 high-confidence SNPs were assigned to 24 consensus linkage groups (LGs. The total length of the genetic linkage map was 5451.3 cM with an average distance of 0.54 cM between loci. This represents the densest genetic map currently reported for large yellow croaker. Using 2889 SNPs to target specific scaffolds, we assigned 533 scaffolds, comprising 421.44 Mb (62.04% of the large yellow croaker assembled sequence, to the 24 linkage groups. The mapped assembly scaffolds in large yellow croaker were used for genome synteny analyses against the stickleback (Gasterosteus aculeatus and medaka (Oryzias latipes. Greater synteny was observed between large yellow croaker and stickleback. This supports the hypothesis that large yellow croaker is more closely related to stickleback than to medaka. Moreover, 1274 immunity-related genes and 195 hypoxia-related genes were mapped to the 24 chromosomes of large yellow croaker. The integration of the high-resolution genetic map and the assembled sequence provides a valuable resource for fine mapping and positional cloning of quantitative trait loci associated with economically important traits in large yellow croaker.

  10. Genetic linkage map of cowpea (Vigna unguiculata (L.) Walp) using ...

    African Journals Online (AJOL)

    DR.ADETUNMBI

    2016-05-18

    May 18, 2016 ... Single seed descent method of breeding was used to generate mapping population between IT-95K-193- ... world with an annual world production estimated at about .... Programme, Mexico for funding the genotyping of the.

  11. Dissecting the genetics of complex inheritance: linkage disequilibrium mapping provides insight into Crohn disease.

    Science.gov (United States)

    Elding, Heather; Lau, Winston; Swallow, Dallas M; Maniatis, Nikolas

    2011-12-09

    Family studies for Crohn disease (CD) report extensive linkage on chromosome 16q and pinpoint NOD2 as a possible causative locus. However, linkage is also observed in families that do not bear the most frequent NOD2 causative mutations, but no other signals on 16q have been found so far in published genome-wide association studies. Our aim is to identify this missing genetic contribution. We apply a powerful genetic mapping approach to the Wellcome Trust Case-Control Consortium and the National Institute of Diabetes and Digestive and Kidney Diseases genome-wide association data on CD. This method takes into account the underlying structure of linkage disequilibrium (LD) by using genetic distances from LD maps and provides a location for the causal agent. We find genetic heterogeneity within the NOD2 locus and also show an independent and unsuspected involvement of the neighboring gene, CYLD. We find associations with the IRF8 region and the region containing CDH1 and CDH3, as well as substantial phenotypic and genetic heterogeneity for CD itself. The genes are known to be involved in inflammation and immune dysregulation. These findings provide insight into the genetics of CD and suggest promising directions for understanding disease heterogeneity. The application of this method thus paves the way for understanding complex inheritance in general, leading to the dissection of different pathways and ultimately, personalized treatment. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  12. Genetic linkage map of Brassica campestris L.using AFLP and RAPD markers

    Institute of Scientific and Technical Information of China (English)

    卢钢; 陈杭; 等

    2002-01-01

    A genetic linkage map comprised of 131 loci was constructed with an F2 population derived from an inter-subspecific cross between Brassica campestris L.ssp.chinensis cv.aijiaohang” and ssp.rapifera cv.,”'isihai”.The genetic map included 93 RAPD loci,36 AFLP loci and 2 morphological loci organized into 10 main linkage groups(LGs) and 2 small groups,covering 1810.9cM with average distance between adjacent markers being approximately 13.8cM.The map is suitable for identification of molecular markers linked to important agronomic traits.QTL analysis,and even for marker-assisted selection in breeding programs of Chinese cabbage and turnip.

  13. Construction of a genetic linkage map and genetic analysis of domestication related traits in mungbean (Vigna radiata.

    Directory of Open Access Journals (Sweden)

    Takehisa Isemura

    Full Text Available The genetic differences between mungbean and its presumed wild ancestor were analyzed for domestication related traits by QTL mapping. A genetic linkage map of mungbean was constructed using 430 SSR and EST-SSR markers from mungbean and its related species, and all these markers were mapped onto 11 linkage groups spanning a total of 727.6 cM. The present mungbean map is the first map where the number of linkage groups coincided with the haploid chromosome number of mungbean. In total 105 QTLs and genes for 38 domestication related traits were identified. Compared with the situation in other Vigna crops, many linkage groups have played an important role in the domestication of mungbean. In particular the QTLs with high contribution were distributed on seven out of 11 linkage groups. In addition, a large number of QTLs with small contribution were found. The accumulation of many mutations with large and/or small contribution has contributed to the differentiation between wild and cultivated mungbean. The useful QTLs for seed size, pod dehiscence and pod maturity that have not been found in other Asian Vigna species were identified in mungbean, and these QTLs may play the important role as new gene resources for other Asian Vigna species. The results provide the foundation that will be useful for improvement of mungbean and related legumes.

  14. A new genetic linkage map of the zygomycete fungus Phycomyces blakesleeanus.

    Directory of Open Access Journals (Sweden)

    Suman Chaudhary

    Full Text Available Phycomyces blakesleeanus is a member of the subphylum Mucoromycotina. A genetic map was constructed from 121 progeny of a cross between two wild type isolates of P. blakesleeanus with 134 markers. The markers were mostly PCR-RFLPs. Markers were located on 46 scaffolds of the genome sequence, covering more than 97% of the genome. Analysis of the alleles in the progeny revealed nine or 12 linkage groups, depending on the log of the odds (LOD score, across 1583.4 cM at LOD 5. The linkage groups were overlaid on previous mapping data from crosses between mutants, aided by new identification of the mutations in primary metabolism mutant strains. The molecular marker map, the phenotype map and the genome sequence are overall congruent, with some exceptions. The new genetic map provides a genome-wide estimate for recombination, with the average of 33.2 kb per cM. This frequency is one piece of evidence for meiosis during zygospore development in Mucoromycotina species. At the same time as meiosis, transmission of non-recombinant chromosomes is also evident in the mating process in Phycomyces. The new map provides scaffold ordering for the genome sequence and a platform upon which to identify the genes in mutants that are affected in traits of interest, such as carotene biosynthesis, phototropism or gravitropism, using positional cloning.

  15. Diversity array technology markers: genetic diversity analyses and linkage map construction in rapeseed (Brassica napus L.).

    Science.gov (United States)

    Raman, Harsh; Raman, Rosy; Nelson, Matthew N; Aslam, M N; Rajasekaran, Ravikesavan; Wratten, Neil; Cowling, Wallace A; Kilian, A; Sharpe, Andrew G; Schondelmaier, Joerg

    2012-01-01

    We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines 'Lynx-037DH' and 'Monty-028DH'. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.

  16. Genetic mapping of X-linked ocular albinism: Linkage analysis in a large Newfoundland kindred

    Energy Technology Data Exchange (ETDEWEB)

    Charles, S.J.; Moore, A.T.; Barton, D.E.; Yates, J.R.W. (Addenbrooke' s Hospital, Cambridge (United Kingdom)); Green, J.S. (Memorial Univ. of Newfoundland, St. John' s (Canada))

    1993-04-01

    Genetic linkage studies in a large Newfoundland family affected by X-linked ocular albinism (OA1) showed linkage to markers from Xp22.3. One recombinant mapped the disease proximal to DXS143 (dic56) and two recombinants mapped the disease distal to DXS85 (782). Combining the data with that from 16 British families previously published confirmed close linkage between OA1 and DXS143 (dic56; Z[sub max] = 21.96 at [theta] = 0.01, confidence interval (CI) 0.0005--0.05) and linkage to DXS85 (782; Z[sub max] = 17.60 at [theta] = 0.07, CI = 0.03--0.13) and DXS237 (GMGX9; Z[sub max] = 15.20 at [theta] = 0.08, CI = 0.03--0.15). Multipoint analysis (LINKMAP) gave the most likely order as Xpter-XG-DXS237-DXS143-OA1-DXS85, with odds of 48:1 over the order Xpter-XG-DXS237-OA1-DXS143-DXS85, and odds exceeding 10[sup 10]:1 over other locations for the disease locus. 11 refs., 1 fig., 1 tab.

  17. Genetic Linkage Map Construction and QTL Analysis of Two Interspecific Reproductive Isolation Traits in Sponge Gourd

    Science.gov (United States)

    Wu, Haibin; He, Xiaoli; Gong, Hao; Luo, Shaobo; Li, Mingzhu; Chen, Junqiu; Zhang, Changyuan; Yu, Ting; Huang, Wangping; Luo, Jianning

    2016-01-01

    The hybrids between Luffa acutangula (L.) Roxb. and L.cylindrica (L.) Roem. have strong heterosis effects. However, some reproductive isolation traits hindered their normal hybridization and fructification, which was mainly caused by the flowering time and hybrid pollen sterility. In order to study the genetic basis of two interspecific reproductive isolation traits, we constructed a genetic linkage map using an F2 population derived from a cross between S1174 [L. acutangula (L.) Roxb.] and 93075 [L. cylindrica (L.) Roem.]. The map spans 1436.12 CentiMorgans (cM), with an average of 8.11 cM among markers, and consists of 177 EST-SSR markers distributed in 14 linkage groups (LG) with an average of 102.58 cM per LG. Meanwhile, we conducted colinearity analysis between the sequences of EST-SSR markers and the genomic sequences of cucumber, melon and watermelon. On the basis of genetic linkage map, we conducted QTL mapping of two reproductive isolation traits in sponge gourd, which were the flowering time and hybrid male sterility. Two putative QTLs associated with flowering time (FT) were both detected on LG 1. The accumulated contribution of these two QTLs explained 38.07% of the total phenotypic variance (PV), and each QTL explained 15.36 and 22.71% of the PV respectively. Four QTLs for pollen fertility (PF) were identified on LG 1 (qPF1.1 and qPF1.2), LG 3 (qPF3) and LG 7 (qPF7), respectively. The percentage of PF explained by these QTLs varied from 2.91 to 16.79%, and all together the four QTLs accounted for 39.98% of the total PV. Our newly developed EST-SSR markers and linkage map are very useful for gene mapping, comparative genomics and molecular marker-assisted breeding. These QTLs for interspecific reproductive isolation will also contribute to the cloning of genes relating to interspecific reproductive isolation and the utilization of interspecific heterosis in sponge gourd in further studies. PMID:27458467

  18. Genetic linkage map of a wild genome: genomic structure, recombination and sexual dimorphism in bighorn sheep

    Directory of Open Access Journals (Sweden)

    Miller Joshua M

    2010-09-01

    Full Text Available Abstract Background The construction of genetic linkage maps in free-living populations is a promising tool for the study of evolution. However, such maps are rare because it is difficult to develop both wild pedigrees and corresponding sets of molecular markers that are sufficiently large. We took advantage of two long-term field studies of pedigreed individuals and genomic resources originally developed for domestic sheep (Ovis aries to construct a linkage map for bighorn sheep, Ovis canadensis. We then assessed variability in genomic structure and recombination rates between bighorn sheep populations and sheep species. Results Bighorn sheep population-specific maps differed slightly in contiguity but were otherwise very similar in terms of genomic structure and recombination rates. The joint analysis of the two pedigrees resulted in a highly contiguous map composed of 247 microsatellite markers distributed along all 26 autosomes and the X chromosome. The map is estimated to cover about 84% of the bighorn sheep genome and contains 240 unique positions spanning a sex-averaged distance of 3051 cM with an average inter-marker distance of 14.3 cM. Marker synteny, order, sex-averaged interval lengths and sex-averaged total map lengths were all very similar between sheep species. However, in contrast to domestic sheep, but consistent with the usual pattern for a placental mammal, recombination rates in bighorn sheep were significantly greater in females than in males (~12% difference, resulting in an autosomal female map of 3166 cM and an autosomal male map of 2831 cM. Despite differing genome-wide patterns of heterochiasmy between the sheep species, sexual dimorphism in recombination rates was correlated between orthologous intervals. Conclusions We have developed a first-generation bighorn sheep linkage map that will facilitate future studies of the genetic architecture of trait variation in this species. While domestication has been hypothesized

  19. Genetic linkage maps for Asian and American lotus constructed using novel SSR markers derived from the genome of sequenced cultivar

    Directory of Open Access Journals (Sweden)

    Yang Mei

    2012-11-01

    Full Text Available Abstract Background The genus Nelumbo Adans. comprises two living species, N. nucifera Gaertan. (Asian lotus and N. lutea Pers. (American lotus. A genetic linkage map is an essential resource for plant genetic studies and crop improvement but has not been generated for Nelumbo. We aimed to develop genomic simple sequence repeat (SSR markers from the genome sequence and construct two genetic maps for Nelumbo to assist genome assembly and integration of a genetic map with the genome sequence. Results A total of 86,089 SSR motifs were identified from the genome sequences. Di- and tri-nucleotide repeat motifs were the most abundant, and accounted for 60.73% and 31.66% of all SSRs, respectively. AG/GA repeats constituted 51.17% of dinucleotide repeat motifs, followed by AT/TA (44.29%. Of 500 SSR primers tested, 386 (77.20% produced scorable alleles with an average of 2.59 per primer, and 185 (37.00% showed polymorphism among two parental genotypes, N. nucifera ‘Chinese Antique’ and N. lutea ‘AL1’, and six progenies of their F1 population. The normally segregating markers, which comprised 268 newly developed SSRs, 37 previously published SSRs and 53 sequence-related amplified polymorphism markers, were used for genetic map construction. The map for Asian lotus was 365.67 cM with 47 markers distributed in seven linkage groups. The map for American lotus was 524.51 cM, and contained 177 markers distributed in 11 genetic linkage groups. The number of markers per linkage group ranged from three to 34 with an average genetic distance of 3.97 cM between adjacent markers. Moreover, 171 SSR markers contained in linkage groups were anchored to 97 genomic DNA sequence contigs of ‘Chinese Antique’. The 97 contigs were merged into 60 scaffolds. Conclusion Genetic mapping of SSR markers derived from sequenced contigs in Nelumbo enabled the associated contigs to be anchored in the linkage map and facilitated assembly of the genome sequences of

  20. Construction of a microsatellite-based genetic linkage map for half-smooth tongue sole Cynoglossus semilaevis

    Institute of Scientific and Technical Information of China (English)

    Wentao SONG; Guidong MIAO; Yongwei ZHAO; Yuze NIU; Renyi PANG; Xiaolin LIAO; Changwei SHAO

    2013-01-01

    The half-smooth tongue sole Cynoglossus semilaevis is an important cultured marine fish and a promising model fish for the study of sex determination.Sex-specific genetic linkage maps of half-smooth tongue sole were developed with 567 markers (565 microsatellite markers and two SCAR markers).The parents and F1 progeny (92 individuals) were used as segregating populations.The female map was composed of 480 markers in 21 linkage groups,covering a total of 1388.1 cM,with an average interval 3.06 cM between markers.The male map consisted of 417 markers in 21 linkage groups,spanning 1480.9 cM,with an average interval of 3.75 cM.The female and male maps had 474 and 416 unique positions,respectively.The genome length of half-smooth tongue sole was estimated to be 1522.9 cM for females and 1649.1cM for males.Based on estimations of map length,the female and male maps covered 91.1% and 89.8% of the genome,respectively.Furthermore,two female-specific SCAR markers,f-382 and f-783,were mapped on LG15f (linkage group 15 in female maps).The present study presents a mid-density genetic linkage map for half-smooth tongue sole.These improved genetic linkage maps may facilitate systematic genome searches to identify quantitative trait loci (QTL),such as disease resistance,growth and sex-related traits,and are very useful for marker-assisted selection breeding programs for economically important traits in half-smooth tongue sole [Current Zoology 59 (1):31-52,2013].

  1. Genetic Linkage Mapping of Economically Important Traits in Cultivated Tetraploid Potato (Solanum tuberosum L.).

    Science.gov (United States)

    Massa, Alicia N; Manrique-Carpintero, Norma C; Coombs, Joseph J; Zarka, Daniel G; Boone, Anne E; Kirk, William W; Hackett, Christine A; Bryan, Glenn J; Douches, David S

    2015-09-14

    The objective of this study was to construct a single nucleotide polymorphism (SNP)-based genetic map at the cultivated tetraploid level to locate quantitative trait loci (QTL) contributing to economically important traits in potato (Solanum tuberosum L.). The 156 F1 progeny and parents of a cross (MSL603) between "Jacqueline Lee" and "MSG227-2" were genotyped using the Infinium 8303 Potato Array. Furthermore, the progeny and parents were evaluated for foliar late blight reaction to isolates of the US-8 genotype of Phytophthora infestans (Mont.) de Bary and vine maturity. Linkage analyses and QTL mapping were performed using a novel approach that incorporates allele dosage information. The resulting genetic maps contained 1972 SNP markers with an average density of 1.36 marker per cM. QTL mapping identified the major source of late blight resistance in "Jacqueline Lee." The best SNP marker mapped ~0.54 Mb from a resistance hotspot on the long arm of chromosome 9. For vine maturity, the major-effect QTL was located on chromosome 5 with allelic effects from both parents. A candidate SNP marker for this trait mapped ~0.25 Mb from the StCDF1 gene, which is a candidate gene for the maturity trait. The identification of markers for P. infestans resistance will enable the introgression of multiple sources of resistance through marker-assisted selection. Moreover, the discovery of a QTL for late blight resistance not linked to the QTL for vine maturity provides the opportunity to use marker-assisted selection for resistance independent of the selection for vine maturity classifications.

  2. Genetic recombination in Escherichia coli : I. Relation between linkage of unselected markers and map distance

    NARCIS (Netherlands)

    Verhoef, C.; Haan, P.G. de

    1966-01-01

    A relation between linkage frequency of an unselected marker and transfer time based on a physical exchange of genetic material was developed for Escherichia coli crosses. Crosses performed under standardised conditions have shown that the relation was valid. The linkage frequency is determined by t

  3. Physical mapping of 49 microsatellite markers on chromosome 19 and correlation with the genetic linkage map

    Energy Technology Data Exchange (ETDEWEB)

    Reguigne-Arnould, I.; Mollicone, R.; Candelier, J.J. [INSERM, Villejuif (France)] [and others

    1996-03-05

    We have regionally localized 49 microsatellite markers developed by Genethon using a panel of previously characterized somatic cell hybrids that retain fragments from chromosome 19. The tight correlation observed between the physical and the genetic orders of the microsatellites provide cytogenetic anchorages to the genetic map data. We propose a position for the centromere just above D19S415, from the study of two hybrids, each of which retains one of the two derivatives of a balanced translocation t(1;19)(q11;q11). Microsatellites, which can be identified by a standard PCR protocol, are useful tools for the localization of disease genes and for the establishment of YAC or cosmid contigs. These markers can also judiciously be used for the characterization of new hybrid cell line panels. We report such a characterization of 11 clones, 8 of which were obtained by irradiation-fusion. Using the whole hybrid panel, we were able to define the order of 12 pairs of genetically colocalized microsatellites. As examples of gene mapping by the combined use of microsatellites and hybrid cell lines, we regionally assigned the PVS locus between the 19q13.2 markers D19S417 and D19S423 and confirmed the locations of fucosyltransferase loci FUT1, FUT2, and FUT5. 13 refs., 1 fig.

  4. Construction of a genetic linkage map of black gram, Vigna mungo (L.) Hepper, based on molecular markers and comparative studies.

    Science.gov (United States)

    Gupta, S K; Souframanien, J; Gopalakrishna, T

    2008-08-01

    A genetic linkage map of black gram, Vigna mungo (L.) Hepper, was constructed with 428 molecular markers using an F9 recombinant inbred population of 104 individuals. The population was derived from an inter-subspecific cross between a black gram cultivar, TU94-2, and a wild genotype, V. mungo var. silvestris. The linkage analysis at a LOD score of 5.0 distributed all 428 markers (254 AFLP, 47 SSR, 86 RAPD, and 41 ISSR) into 11 linkage groups. The map spanned a total distance of 865.1 cM with an average marker density of 2 cM. The largest linkage group spanned 115 cM and the smallest linkage group was of 44.9 cM. The number of markers per linkage group ranged from 11 to 86 and the average distance between markers varied from 1.1 to 5.6 cM. Comparison of the map with other published azuki bean and black gram maps showed high colinearity of markers, with some inversions. The current map is the most saturated map for black gram to date and will provide a useful tool for identification of QTLs and for marker-assisted selection of agronomically important characters in black gram.

  5. A Genetic Linkage Map of Brassica rapa Based on AFLP Markers

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jian-jun; WANG Xiao-wu; Guusje Bonnema; SUN Ri-fei; XU Ze-yong; Dick Vreugdenhi; Maarten Koornneef

    2005-01-01

    A F2 mapping population was developed by crossing a Chinese cabbage-pe-tsai variety CC156 and an oil type Rapid cycling RC144 which were different from each other in morphology, maturity, self-compatibility, plant height, etc. Using 244 AFLP markers a map was constructed containing 10 main linkage groups covering a total distance of 857 cM,corresponding to 3.5 cM per marker. Length of linkage groups varied from 43 to 125 cM and the number of AFLP markers linkage to each group ranged from 7 to 41.

  6. Construction of Genetic Linkage Map of Bread Wheat (Triticum aestivum L.) Using an Intervarietal Cross and QTL Map for Spike Related Traits

    Institute of Scientific and Technical Information of China (English)

    E. Nalini; S.G. Bhagwat; N. Jawali

    2007-01-01

    @@ Most often a genetic linkage map is prepared using populations obtained from two highly diverse genotypes.However, the markers from such a map may not be useful in a breeding program as these markers may not be polymorphie among the varieties used in breeding.

  7. The first genetic linkage map of Primulina eburnea (Gesneriaceae) based on EST-derived SNP markers.

    Science.gov (United States)

    Feng, Chen; Feng, Chao; Kang, Ming

    2016-06-01

    Primulina eburnea is a promising candidate for domestication and floriculture, since it is easy to culture and has beautiful flowers. An F₂ population of 189 individuals was established for the construction of first-generation linkage maps based on expressed sequence tags-derived single-nucleotide polymorphism markers using the massARRAY genotyping platform. Of the 232 screened markers, 215 were assigned to 18 LG according to the haploid number of chromosomes in the species. The linkage map spanned a total of 3774.7 cM with an average distance of 17.6 cM between adjacent markers. This linkage map provides a framework for identification of important genes in breeding programmes.

  8. First genetic linkage map of Taraxacum koksaghyz Rodin based on AFLP, SSR, COS and EST-SSR markers

    Science.gov (United States)

    Arias, Marina; Hernandez, Monica; Remondegui, Naroa; Huvenaars, Koen; van Dijk, Peter; Ritter, Enrique

    2016-01-01

    Taraxacum koksaghyz Rodin (TKS) has been studied in many occasions as a possible alternative source for natural rubber production of good quality and for inulin production. Some tire companies are already testing TKS tire prototypes. There are also many investigations on the production of bio-fuels from inulin and inulin applications for health improvement and in the food industry. A limited amount of genomic resources exist for TKS and particularly no genetic linkage map is available in this species. We have constructed the first TKS genetic linkage map based on AFLP, COS, SSR and EST-SSR markers. The integrated linkage map with eight linkage groups (LG), representing the eight chromosomes of Russian dandelion, has 185 individual AFLP markers from parent 1, 188 individual AFLP markers from parent 2, 75 common AFLP markers and 6 COS, 1 SSR and 63 EST-SSR loci. Blasting the EST-SSR sequences against known sequences from lettuce allowed a partial alignment of our TKS map with a lettuce map. Blast searches against plant gene databases revealed some homologies with useful genes for downstream applications in the future. PMID:27488242

  9. First genetic linkage map of Taraxacum koksaghyz Rodin based on AFLP, SSR, COS and EST-SSR markers.

    Science.gov (United States)

    Arias, Marina; Hernandez, Monica; Remondegui, Naroa; Huvenaars, Koen; van Dijk, Peter; Ritter, Enrique

    2016-08-04

    Taraxacum koksaghyz Rodin (TKS) has been studied in many occasions as a possible alternative source for natural rubber production of good quality and for inulin production. Some tire companies are already testing TKS tire prototypes. There are also many investigations on the production of bio-fuels from inulin and inulin applications for health improvement and in the food industry. A limited amount of genomic resources exist for TKS and particularly no genetic linkage map is available in this species. We have constructed the first TKS genetic linkage map based on AFLP, COS, SSR and EST-SSR markers. The integrated linkage map with eight linkage groups (LG), representing the eight chromosomes of Russian dandelion, has 185 individual AFLP markers from parent 1, 188 individual AFLP markers from parent 2, 75 common AFLP markers and 6 COS, 1 SSR and 63 EST-SSR loci. Blasting the EST-SSR sequences against known sequences from lettuce allowed a partial alignment of our TKS map with a lettuce map. Blast searches against plant gene databases revealed some homologies with useful genes for downstream applications in the future.

  10. The Genetic Linkage Map of the Medicinal Mushroom Agaricus subrufescens Reveals Highly Conserved Macrosynteny with the Congeneric Species Agaricus bisporus

    Directory of Open Access Journals (Sweden)

    Marie Foulongne-Oriol

    2016-05-01

    Full Text Available Comparative linkage mapping can rapidly facilitate the transfer of genetic information from model species to orphan species. This macrosynteny analysis approach has been extensively used in plant species, but few example are available in fungi, and even fewer in mushroom crop species. Among the latter, the Agaricus genus comprises the most cultivable or potentially cultivable species. Agaricus bisporus, the button mushroom, is the model for edible and cultivable mushrooms. We have developed the first genetic linkage map for the basidiomycete A. subrufescens, an emerging mushroom crop known for its therapeutic properties and potential medicinal applications. The map includes 202 markers distributed over 16 linkage groups (LG, and covers a total length of 1701 cM, with an average marker spacing of 8.2 cM. Using 96 homologous loci, we also demonstrated the high level of macrosynteny with the genome of A. bisporus. The 13 main LG of A. subrufescens were syntenic to the 13 A. bisporus chromosomes. A disrupted synteny was observed for the three remaining A. subrufescens LG. Electronic mapping of a collection of A. subrufescens expressed sequence tags on A. bisporus genome showed that the homologous loci were evenly spread, with the exception of a few local hot or cold spots of homology. Our results were discussed in the light of Agaricus species evolution process. The map provides a framework for future genetic or genomic studies of the medicinal mushroom A. subrufescens.

  11. The Genetic Linkage Map of the Medicinal Mushroom Agaricus subrufescens Reveals Highly Conserved Macrosynteny with the Congeneric Species Agaricus bisporus

    Science.gov (United States)

    Foulongne-Oriol, Marie; Rocha de Brito, Manuela; Cabannes, Delphine; Clément, Aurélien; Spataro, Cathy; Moinard, Magalie; Dias, Eustáquio Souza; Callac, Philippe; Savoie, Jean-Michel

    2016-01-01

    Comparative linkage mapping can rapidly facilitate the transfer of genetic information from model species to orphan species. This macrosynteny analysis approach has been extensively used in plant species, but few example are available in fungi, and even fewer in mushroom crop species. Among the latter, the Agaricus genus comprises the most cultivable or potentially cultivable species. Agaricus bisporus, the button mushroom, is the model for edible and cultivable mushrooms. We have developed the first genetic linkage map for the basidiomycete A. subrufescens, an emerging mushroom crop known for its therapeutic properties and potential medicinal applications. The map includes 202 markers distributed over 16 linkage groups (LG), and covers a total length of 1701 cM, with an average marker spacing of 8.2 cM. Using 96 homologous loci, we also demonstrated the high level of macrosynteny with the genome of A. bisporus. The 13 main LG of A. subrufescens were syntenic to the 13 A. bisporus chromosomes. A disrupted synteny was observed for the three remaining A. subrufescens LG. Electronic mapping of a collection of A. subrufescens expressed sequence tags on A. bisporus genome showed that the homologous loci were evenly spread, with the exception of a few local hot or cold spots of homology. Our results were discussed in the light of Agaricus species evolution process. The map provides a framework for future genetic or genomic studies of the medicinal mushroom A. subrufescens. PMID:26921302

  12. Genetic linkage map and expression analysis of genes expressed in the lamellae of the edible basidiomycete Pleurotus ostreatus.

    Science.gov (United States)

    Park, Sang-Kyu; Peñas, María M; Ramírez, Lucía; Pisabarro, Antonio G

    2006-05-01

    Pleurotus ostreatus is an industrially cultivated basidiomycete with nutritional and environmental applications. Its genome contains 35 Mbp organized in 11 chromosomes. There is currently available a genetic linkage map based predominantly on anonymous molecular markers complemented with the mapping of QTLs controlling growth rate and industrial productivity. To increase the saturation of the existing linkage maps, we have identified and mapped 82 genes expressed in the lamellae. Their manual annotation revealed that 34.1% of the lamellae-expressed and 71.5% of the lamellae-specific genes correspond to previously unknown sequences or to hypothetical proteins without a clearly established function. Furthermore, the expression pattern of some genes provides an experimental basis for studying gene regulation during the change from vegetative to reproductive growth. Finally, the identification of various differentially regulated genes involved in protein metabolism suggests the relevance of these processes in fruit body formation and maturation.

  13. Construction of a genetic linkage map and QTL analysis for some leaf traits in pear (Pyrus L .)

    Institute of Scientific and Technical Information of China (English)

    Wenying SUN; Yuxing ZHANG; Wenquan LE; Hai'e ZHANG

    2009-01-01

    The major incompatibility barriers to specific inbred lines and the long generation duration in Pyrus L. May hinder the Pyrus breeding process. A genetic linkage map provides the foundation for quantitative trait loci (QTL) mapping and molecular marker-assisted breeding. In this study, we constructed a genetic map with 145 F1 populations from a cross of two cultivars, Yali and Jingbaili, using AFLP and SSR markers. The map consisted of 18 linkage groups which included 402 genetic markers and covered 1395.9 cM, with an average genetic distance of 3.8 cM. The interval mapping was used to identify quantitative trait loci associated with four leaf agronomic traits in the F1 population. The results indicated that four QTLs were associated with leaf length, two QTLs with leaf width, two with leaf length/leaf width, and three with petiole length. The eleven QTLs were associated with 9.9%-48.5% of the phenotypic variation in different traits. It is considered that the map covers almost the whole genome, and molecular markers will be greatly helpful to the related breeding.

  14. Advancing the STMS genomic resources for defining new locations on the intraspecific genetic linkage map of chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Gaur, Rashmi; Sethy, Niroj K; Choudhary, Shalu; Shokeen, Bhumika; Gupta, Varsha; Bhatia, Sabhyata

    2011-02-17

    Chickpea (Cicer arietinum L.) is an economically important cool season grain legume crop that is valued for its nutritive seeds having high protein content. However, several biotic and abiotic stresses and the low genetic variability in the chickpea genome have continuously hindered the chickpea molecular breeding programs. STMS (Sequence Tagged Microsatellite Sites) markers which are preferred for the construction of saturated linkage maps in several crop species, have also emerged as the most efficient and reliable source for detecting allelic diversity in chickpea. However, the number of STMS markers reported in chickpea is still limited and moreover exhibit low rates of both inter and intraspecific polymorphism, thereby limiting the positions of the SSR markers especially on the intraspecific linkage maps of chickpea. Hence, this study was undertaken with the aim of developing additional STMS markers and utilizing them for advancing the genetic linkage map of chickpea which would have applications in QTL identification, MAS and for de novo assembly of high throughput whole genome sequence data. A microsatellite enriched library of chickpea (enriched for (GT/CA)n and (GA/CT)n repeats) was constructed from which 387 putative microsatellite containing clones were identified. From these, 254 STMS primers were designed of which 181 were developed as functional markers. An intraspecific mapping population of chickpea, [ICCV-2 (single podded) × JG-62 (double podded)] and comprising of 126 RILs, was genotyped for mapping. Of the 522 chickpea STMS markers (including the double-podding trait, screened for parental polymorphism, 226 (43.3%) were polymorphic in the parents and were used to genotype the RILs. At a LOD score of 3.5, eight linkage groups defining the position of 138 markers were obtained that spanned 630.9 cM with an average marker density of 4.57 cM. Further, based on the common loci present between the current map and the previously published chickpea

  15. Development of a molecular genetic linkage map for Colletotrichum lindemuthianum and segregation analysis of two avirulence genes.

    Science.gov (United States)

    Luna-Martínez, Francisco; Rodríguez-Guerra, Raúl; Victoria-Campos, Mayra; Simpson, June

    2007-02-01

    A framework genetic map was developed for the fungal pathogen Colletotrichum lindemuthianum, the causal agent of anthracnose of common bean (Phaseolus vulgaris L.). This is the first genetic map for any species within the family Melanconiaceae and the genus Colletotrichum and provides the first estimate of genome length for C. lindemuthianum. The map was generated using 106 haploid F1 progeny derived from crossing two Mexican C. lindemuthianum isolates differing in two avirulence genes (AvrclMex and AvrclTO). The map comprises 165 AFLP markers covering 1,897 cM with an average spacing of 11.49 cM. The markers are distributed over 19 major linkage groups containing between 5 and 25 markers each and the genome length was estimated to be approximately 3,241 cM. The avirulence genes AvrclMex and AvrclTO segregate in a 1:1 ratio supporting the gene for gene hypothesis for the incompatible reaction between C. lindemuthianum and P. vulgaris, but could not be incorporated into the genetic map. This initial outline map forms the basis for the development of a more detailed C. lindemuthianum linkage map, which would include other types of molecular markers and allow the location of genes previously isolated and characterized in this species.

  16. Identification of QTLs associated with callogenesis and embryogenesis in oil palm using genetic linkage maps improved with SSR markers.

    Directory of Open Access Journals (Sweden)

    Ngoot-Chin Ting

    Full Text Available Clonal reproduction of oil palm by means of tissue culture is a very inefficient process. Tissue culturability is known to be genotype dependent with some genotypes being more amenable to tissue culture than others. In this study, genetic linkage maps enriched with simple sequence repeat (SSR markers were developed for dura (ENL48 and pisifera (ML161, the two fruit forms of oil palm, Elaeis guineensis. The SSR markers were mapped onto earlier reported parental maps based on amplified fragment length polymorphism (AFLP and restriction fragment length polymorphism (RFLP markers. The new linkage map of ENL48 contains 148 markers (33 AFLPs, 38 RFLPs and 77 SSRs in 23 linkage groups (LGs, covering a total map length of 798.0 cM. The ML161 map contains 240 markers (50 AFLPs, 71 RFLPs and 119 SSRs in 24 LGs covering a total of 1,328.1 cM. Using the improved maps, two quantitative trait loci (QTLs associated with tissue culturability were identified each for callusing rate and embryogenesis rate. A QTL for callogenesis was identified in LGD4b of ENL48 and explained 17.5% of the phenotypic variation. For embryogenesis rate, a QTL was detected on LGP16b in ML161 and explained 20.1% of the variation. This study is the first attempt to identify QTL associated with tissue culture amenity in oil palm which is an important step towards understanding the molecular processes underlying clonal regeneration of oil palm.

  17. A genetic linkage map for hazelnut (Corylus avellana L.) based on RAPD and SSR markers.

    Science.gov (United States)

    Mehlenbacher, Shawn A; Brown, Rebecca N; Nouhra, Eduardo R; Gökirmak, Tufan; Bassil, Nahla V; Kubisiak, Thomas L

    2006-02-01

    A linkage map for European hazelnut (Corylus avellana L.) was constructed using random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers and the 2-way pseudotestcross approach. A full-sib population of 144 seedlings from the cross OSU 252.146 x OSU 414.062 was used. RAPD markers in testcross configuration, segregating 1:1, were used to construct separate maps for each parent. Fifty additional RAPD loci were assigned to linkage groups as accessory markers whose exact location could not be determined. Markers in intercross configuration, segregating 3:1, were used to pair groups in one parent with their homologues in the other. Eleven groups were identified for each parent, corresponding to the haploid chromosome number of hazelnut (n = x = 11). Thirty of the 31 SSR loci were able to be assigned to a linkage group. The maternal map included 249 RAPD and 20 SSR markers and spanned a distance of 661 cM. The paternal map included 271 RAPD and 28 SSR markers and spanned a distance of 812 cM. The maps are quite dense, with an average of 2.6 cM between adjacent markers. The S-locus, which controls pollen-stigma incompatibility, was placed on chromosome 5S where 6 markers linked within a distance of 10 cM were identified. A locus for resistance to eastern filbert blight, caused by Anisogramma anomala, was placed on chromosome 6R for which two additional markers tightly linked to the dominant allele were identified and sequenced. These maps will serve as a starting point for future studies of the hazelnut genome, including map-based cloning of important genes. The inclusion of SSR loci on the map will make it useful in other populations.

  18. THREaD Mapper Studio: a novel, visual web server for the estimation of genetic linkage maps.

    Science.gov (United States)

    Cheema, Jitender; Ellis, T H Noel; Dicks, Jo

    2010-07-01

    The estimation of genetic linkage maps is a key component in plant and animal research, providing both an indication of the genetic structure of an organism and a mechanism for identifying candidate genes associated with traits of interest. Because of this importance, several computational solutions to genetic map estimation exist, mostly implemented as stand-alone software packages. However, the estimation process is often largely hidden from the user. Consequently, problems such as a program crashing may occur that leave a user baffled. THREaD Mapper Studio (http://cbr.jic.ac.uk/threadmapper) is a new web site that implements a novel, visual and interactive method for the estimation of genetic linkage maps from DNA markers. The rationale behind the web site is to make the estimation process as transparent and robust as possible, while also allowing users to use their expert knowledge during analysis. Indeed, the 3D visual nature of the tool allows users to spot features in a data set, such as outlying markers and potential structural rearrangements that could cause problems with the estimation procedure and to account for them in their analysis. Furthermore, THREaD Mapper Studio facilitates the visual comparison of genetic map solutions from third party software, aiding users in developing robust solutions for their data sets.

  19. High density genetic linkage map and bin mapping for disease resistance QTLs in peanut

    Science.gov (United States)

    Mapping and identification of QTLs are important for efficient marker-assisted breeding and for analysis of the molecular mechanisms regulating traits. Diseases, such as early and late leaf spots, Tomato spotted wilt virus (TSWV), cause significant loses to peanut growers. Our goal is to develop a h...

  20. The first genetic linkage map of Primulina eburnea (Gesneriaceae) based on EST-derived SNP marker

    Indian Academy of Sciences (India)

    CHEN FENG; CHAO FENG; MING KANG

    2016-06-01

    Primulina eburneais a promising candidate for domestication and floriculture, since it is easy to culture and has beautiful flow-ers. An F2population of 189 individuals was established for the construction of first-generation linkage maps based onexpressed sequence tags-derived single-nucleotide polymorphism markers using the massARRAY genotyping platform. Ofthe 232 screened markers, 215 were assigned to 18 LG according to the haploid number of chromosomes in the species. Thelinkage map spanned a total of 3774.7 cM with an average distance of 17.6 cM between adjacent markers. This linkage mapprovides a framework for identification of important genes in breeding programm

  1. Genetic mapping of the gene for Usher syndrome: Linkage analysis in a large Samaritan kindred

    Energy Technology Data Exchange (ETDEWEB)

    Bonne-Tamir, B.; Korostishevsky, M.; Kalinsky, H.; Seroussi, E.; Beker, R.; Weiss, S. (Sackler Faculty of Medicine, Ramat-Aviv (Israel)); Godel, V. (Ichilov Hospital, Tel-Aviv (Israel))

    1994-03-01

    Usher syndrome is a group of autosomal recessive disorders associated with congenital sensorineural deafness and progressive visual loss due to retinitis pigmentosa. Sixteen members of the small inbred Samaritan isolate with autosomal recessive deafness from 59 individuals including parents and affected and nonaffected sibs were typed for markers on chromosomes 1q and 11q for which linkage has recently been established for Usher syndrome types II and I. Statistically significant linkage was observed with four markers on 11q (D11S533, D11S527, OMP, and INT2) with a maximum six-point location score of 11.61 at the D11S533 locus. Analysis of haplotypes supports the notion that the mutation arose only once in an ancestral chromosome carrying a specific haplotype. The availability of markers closely linked to the disease locus allows indirect genotype analysis and identifies all carriers of the gene within the community. Furthermore, the detection of complete linkage disequilibrium between the D11S533 marker and the Usher gene suggests that these loci are either identical or adjacent and narrows the critical region to which physical mapping efforts are currently directed. 35 refs., 2 figs., 6 tabs.

  2. Development of di-nucleotide microsatellite markers and construction of genetic linkage map in mango (Mangifera indica L.

    Directory of Open Access Journals (Sweden)

    Chataporn Chunwongse

    2015-04-01

    Full Text Available Forty-two di-nucleotide microsatellite, or simple-sequence repeat (SSR, markers were developed using CA and CTenriched genomic libraries of Mangifera indica L. Six cultivated mangoes and two wild species were tested for primer amplifications. Most loci could amplify M. caloneura Kruz and M. foetida. The average number of alleles per locus was 4.4. The average expected heterozygosity and the maximum polymorphism information content value were 0.57 and 0.53, respectively. The SSRs developed in this study together with 65 SSRs and 145 restriction fragment length polymorphism (RFLP markers reported previously were used in the genetic linkage analysis. A partial genetic linkage map was constructed based on 31 F1 progenies from a cross between ‘Alphonso’ and ‘Palmer’. The map spanned a distance of 529.9 centiMorgan (cM and consisted of 9 microsatellite markers (6 from this study and 67 RFLP markers. The new SSR markers and the present map will be useful for mango genetic studies and breeding applications in the future.

  3. A genetic linkage map of the diplosporous chromosomal region in Taraxacum officinale (common dandelion; Asteracaea)

    NARCIS (Netherlands)

    Vijverberg, K.; Hulst, van der R.G.M.; Lindhout, W.H.; Dijk, P.J.

    2004-01-01

    In this study, we mapped the diplosporous chromosomal region in Taraxacum officinale, by using amplified fragment length polymorphism technology (AFLP) in 73 plants from a segregating population. Taraxacum serves as a model system to investigate the genetics, ecology, and evolution of apomixis. The

  4. A genetic linkage map of the diplosporous chromosomal region in Taraxacum officinale (common dandelion; Asteraceae)

    NARCIS (Netherlands)

    Vijverberg, Kitty; van der Hulst, R.G.M.; Lindhout, P.; Van Dijk, P.J.

    2004-01-01

    In this study, we mapped the diplosporous chromosomal region in Taraxacum officinale, by using amplified fragment length polymorphism technology (AFLP) in 73 plants from a segregating population. Taraxacum serves as a model system to investigate the genetics, ecology, and evolution of apomixis. The

  5. A genetic linkage map of the diplosporous chromosomal region in Taraxacum officinale (common dandelion; Asteracaea)

    NARCIS (Netherlands)

    Vijverberg, K.; Hulst, van der R.G.M.; Lindhout, W.H.; Dijk, P.J.

    2004-01-01

    In this study, we mapped the diplosporous chromosomal region in Taraxacum officinale, by using amplified fragment length polymorphism technology (AFLP) in 73 plants from a segregating population. Taraxacum serves as a model system to investigate the genetics, ecology, and evolution of apomixis. The

  6. A genetic linkage map of the diplosporous chromosomal region in Taraxacum officinale (common dandelion; Asteraceae)

    NARCIS (Netherlands)

    Vijverberg, Kitty; van der Hulst, R.G.M.; Lindhout, P.; Van Dijk, P.J.

    2004-01-01

    In this study, we mapped the diplosporous chromosomal region in Taraxacum officinale, by using amplified fragment length polymorphism technology (AFLP) in 73 plants from a segregating population. Taraxacum serves as a model system to investigate the genetics, ecology, and evolution of apomixis. The

  7. Construction of an integrated genetic linkage map for the A genome of Brassica napus using SSR markers derived from sequenced BACs in B. rapa

    Directory of Open Access Journals (Sweden)

    King Graham J

    2010-10-01

    Full Text Available Abstract Background The Multinational Brassica rapa Genome Sequencing Project (BrGSP has developed valuable genomic resources, including BAC libraries, BAC-end sequences, genetic and physical maps, and seed BAC sequences for Brassica rapa. An integrated linkage map between the amphidiploid B. napus and diploid B. rapa will facilitate the rapid transfer of these valuable resources from B. rapa to B. napus (Oilseed rape, Canola. Results In this study, we identified over 23,000 simple sequence repeats (SSRs from 536 sequenced BACs. 890 SSR markers (designated as BrGMS were developed and used for the construction of an integrated linkage map for the A genome in B. rapa and B. napus. Two hundred and nineteen BrGMS markers were integrated to an existing B. napus linkage map (BnaNZDH. Among these mapped BrGMS markers, 168 were only distributed on the A genome linkage groups (LGs, 18 distrubuted both on the A and C genome LGs, and 33 only distributed on the C genome LGs. Most of the A genome LGs in B. napus were collinear with the homoeologous LGs in B. rapa, although minor inversions or rearrangements occurred on A2 and A9. The mapping of these BAC-specific SSR markers enabled assignment of 161 sequenced B. rapa BACs, as well as the associated BAC contigs to the A genome LGs of B. napus. Conclusion The genetic mapping of SSR markers derived from sequenced BACs in B. rapa enabled direct links to be established between the B. napus linkage map and a B. rapa physical map, and thus the assignment of B. rapa BACs and the associated BAC contigs to the B. napus linkage map. This integrated genetic linkage map will facilitate exploitation of the B. rapa annotated genomic resources for gene tagging and map-based cloning in B. napus, and for comparative analysis of the A genome within Brassica species.

  8. Genetic mapping of horizontal stripes in Lake Victoria cichlid fishes: benefits and pitfalls of using RAD markers for dense linkage mapping.

    Science.gov (United States)

    Henning, Frederico; Lee, Hyuk Je; Franchini, Paolo; Meyer, Axel

    2014-11-01

    The genetic dissection of naturally occurring phenotypes sheds light on many fundamental and longstanding questions in speciation and adaptation and is a central research topic in evolutionary biology. Until recently, forward-genetic approaches were virtually impossible to apply to nonmodel organisms, but the development of next-generation sequencing techniques eases this difficulty. Here, we use the ddRAD-seq method to map a colour trait with a known adaptive function in cichlid fishes, well-known textbook examples for rapid rates of speciation and astonishing phenotypic diversification. A suite of phenotypic key innovations is related to speciation and adaptation in cichlids, among which body coloration features prominently. The focal trait of this study, horizontal stripes, evolved in parallel in several cichlid radiations and is associated with piscivorous foraging behaviour. We conducted interspecific crosses between Haplochromis sauvagei and H. nyererei and constructed a linkage map with 867 SNP markers distributed on 22 linkage groups and total size of 1130.63 cM. Lateral stripes are inherited as a Mendelian trait and map to a single genomic interval that harbours a paralog of a gene with known function in stripe patterning. Dorsolateral and mid-lateral stripes were always coinherited and are thus under the same genetic control. Additionally, we directly quantify the genotyping error rates in RAD markers and offer guidelines for identifying and dealing with errors. Uncritical marker selection was found to severely impact linkage map construction. Fortunately, by applying appropriate quality control steps, a genotyping accuracy of >99.9% can be reached, thus allowing for efficient linkage mapping of evolutionarily relevant traits.

  9. Linkage analysis and map construction in genetic populations of clonal F1 and double cross.

    Science.gov (United States)

    Zhang, Luyan; Li, Huihui; Wang, Jiankang

    2015-01-15

    In this study, we considered four categories of molecular markers based on the number of distinguishable alleles at the marker locus and the number of distinguishable genotypes in clonal F1 progenies. For two marker loci, there are nine scenarios that allow the estimation of female, male, and/or combined recombination frequencies. In a double cross population derived from four inbred lines, five categories of markers are classified and another five scenarios are present for recombination frequency estimation. Theoretical frequencies of identifiable genotypes were given for each scenario, from which the maximum likelihood estimates of one or more of the three recombination frequencies could be estimated. If there was no analytic solution, then Newton-Raphson method was used to acquire a numerical solution. We then proposed to use an algorithm in Traveling Salesman Problem to determine the marker order. Finally, we proposed a procedure to build the two haploids of the female parent and the two haploids of the male parent in clonal F1. Once the four haploids were built, clonal F1 hybrids could be exactly regarded as a double cross population. Efficiency of the proposed methods was demonstrated in simulated clonal F1 populations and one actual maize double cross. Extensive comparisons with software JoinMap4.1, OneMap, and R/qtl show that the methodology proposed in this article can build more accurate linkage maps in less time.

  10. Construction of two genetic linkage maps in cultivated tetraploid alfalfa (Medicago sativa using microsatellite and AFLP markers

    Directory of Open Access Journals (Sweden)

    Santoni Sylvain

    2003-12-01

    Full Text Available Abstract Background Alfalfa (Medicago sativa is a major forage crop. The genetic progress is slow in this legume species because of its autotetraploidy and allogamy. The genetic structure of this species makes the construction of genetic maps difficult. To reach this objective, and to be able to detect QTLs in segregating populations, we used the available codominant microsatellite markers (SSRs, most of them identified in the model legume Medicago truncatula from EST database. A genetic map was constructed with AFLP and SSR markers using specific mapping procedures for autotetraploids. The tetrasomic inheritance was analysed in an alfalfa mapping population. Results We have demonstrated that 80% of primer pairs defined on each side of SSR motifs in M. truncatula EST database amplify with the alfalfa DNA. Using a F1 mapping population of 168 individuals produced from the cross of 2 heterozygous parental plants from Magali and Mercedes cultivars, we obtained 599 AFLP markers and 107 SSR loci. All but 3 SSR loci showed a clear tetrasomic inheritance. For most of the SSR loci, the double-reduction was not significant. For the other loci no specific genotypes were produced, so the significant double-reduction could arise from segregation distortion. For each parent, the genetic map contained 8 groups of four homologous chromosomes. The lengths of the maps were 2649 and 3045 cM, with an average distance of 7.6 and 9.0 cM between markers, for Magali and Mercedes parents, respectively. Using only the SSR markers, we built a composite map covering 709 cM. Conclusions Compared to diploid alfalfa genetic maps, our maps cover about 88–100% of the genome and are close to saturation. The inheritance of the codominant markers (SSR and the pattern of linkage repulsions between markers within each homology group are consistent with the hypothesis of a tetrasomic meiosis in alfalfa. Except for 2 out of 107 SSR markers, we found a similar order of markers on

  11. High-density interspecific genetic linkage mapping provides insights into genomic incompatibility between channel catfish and blue catfish.

    Science.gov (United States)

    Liu, S; Li, Y; Qin, Z; Geng, X; Bao, L; Kaltenboeck, L; Kucuktas, H; Dunham, R; Liu, Z

    2016-02-01

    Catfish is the leading aquaculture species in the United States. The interspecific hybrid catfish produced by mating female channel catfish with male blue catfish outperform both of their parent species in a number of traits. However, mass production of the hybrids has been difficult because of reproductive isolation. Investigations of genome structure and organization of the hybrids provide insights into the genetic basis for maintenance of species divergence in the face of gene flow, thereby helping develop strategies for introgression and efficient production of the hybrids for aquaculture. In this study, we constructed a high-density genetic linkage map using the hybrid catfish system with the catfish 250K SNP array. A total of 26,238 SNPs were mapped to 29 linkage groups, with 12,776 unique marker positions. The linkage map spans approximately 3240 cM with an average intermarker distance of 0.25 cM. A fraction of markers (986 of 12,776) exhibited significant deviation from the expected Mendelian ratio of segregation, and they were clustered in major genomic blocks across 15 LGs, most notably LG9 and LG15. The distorted markers exhibited significant bias for maternal alleles among the backcross progenies, suggesting strong selection against the blue catfish alleles. The clustering of distorted markers within genomic blocks should lend insights into speciation as marked by incompatibilities between the two species. Such findings should also have profound implications for understanding the genomic evolution of closely related species as well as the introgression of hybrid production programs in aquaculture.

  12. Microsatellite isolation and marker development in carrot - genomic distribution, linkage mapping, genetic diversity analysis and marker transferability across Apiaceae

    Directory of Open Access Journals (Sweden)

    Yildiz Mehtap

    2011-08-01

    Full Text Available Abstract Background The Apiaceae family includes several vegetable and spice crop species among which carrot is the most economically important member, with ~21 million tons produced yearly worldwide. Despite its importance, molecular resources in this species are relatively underdeveloped. The availability of informative, polymorphic, and robust PCR-based markers, such as microsatellites (or SSRs, will facilitate genetics and breeding of carrot and other Apiaceae, including integration of linkage maps, tagging of phenotypic traits and assisting positional gene cloning. Thus, with the purpose of isolating carrot microsatellites, two different strategies were used; a hybridization-based library enrichment for SSRs, and bioinformatic mining of SSRs in BAC-end sequence and EST sequence databases. This work reports on the development of 300 carrot SSR markers and their characterization at various levels. Results Evaluation of microsatellites isolated from both DNA sources in subsets of 7 carrot F2 mapping populations revealed that SSRs from the hybridization-based method were longer, had more repeat units and were more polymorphic than SSRs isolated by sequence search. Overall, 196 SSRs (65.1% were polymorphic in at least one mapping population, and the percentage of polymophic SSRs across F2 populations ranged from 17.8 to 24.7. Polymorphic markers in one family were evaluated in the entire F2, allowing the genetic mapping of 55 SSRs (38 codominant onto the carrot reference map. The SSR loci were distributed throughout all 9 carrot linkage groups (LGs, with 2 to 9 SSRs/LG. In addition, SSR evaluations in carrot-related taxa indicated that a significant fraction of the carrot SSRs transfer successfully across Apiaceae, with heterologous amplification success rate decreasing with the target-species evolutionary distance from carrot. SSR diversity evaluated in a collection of 65 D. carota accessions revealed a high level of polymorphism for these

  13. Construction of a genetic linkage map of Thlaspi caerulescens and quantitative trait loci analysis of zinc accumulation.

    Science.gov (United States)

    Assunção, Ana G L; Pieper, Bjorn; Vromans, Jaap; Lindhout, Pim; Aarts, Mark G M; Schat, Henk

    2006-01-01

    Zinc (Zn) hyperaccumulation seems to be a constitutive species-level trait in Thlaspi caerulescens. When compared under conditions of equal Zn availability, considerable variation in the degree of hyperaccumulation is observed among accessions originating from different soil types. This variation offers an excellent opportunity for further dissection of the genetics of this trait. A T. caerulescens intraspecific cross was made between a plant from a nonmetallicolous accession [Lellingen (LE)], characterized by relatively high Zn accumulation, and a plant from a calamine accession [La Calamine (LC)], characterized by relatively low Zn accumulation. Zinc accumulation in roots and shoots segregated in the F3 population. This population was used to construct an LE/LC amplified fragment length polymorphism (AFLP)-based genetic linkage map and to map quantitative trait loci (QTL) for Zn accumulation. Two QTL were identified for root Zn accumulation, with the trait-enhancing alleles being derived from each of the parents, and explaining 21.7 and 16.6% of the phenotypic variation observed in the mapping population. Future development of more markers, based on Arabidopsis orthologous genes localized in the QTL regions, will allow fine-mapping and map-based cloning of the genes underlying the QTL.

  14. Genetic basis of agronomically important traits in sugar beet (Beta vulgaris L.) investigated with joint linkage association mapping.

    Science.gov (United States)

    Reif, Jochen C; Liu, Wenxin; Gowda, Manje; Maurer, Hans Peter; Möhring, Jens; Fischer, Sandra; Schechert, Axel; Würschum, Tobias

    2010-11-01

    Epistatic interactions may contribute substantially to the hybrid performance of sugar beet. The main goal of our study was to dissect the genetic basis of eight important physiological and agronomic traits using two different biometrical models for joint linkage association mapping. A total of 197 genotypes of an elite breeding population were evaluated in multi-location trials and fingerprinted with 194 SNP markers. Two different statistical models were used for the genome-wide scan for marker-trait associations: Model A, which corrects for the genetic background with markers as cofactors and Model B, which additionally models a population effect. Based on the extent of linkage disequilibrium in the parental population, we estimated that for a genome-wide scan at least 100 equally spaced markers are necessary. We mapped across the eight traits 39 QTL for Model A and 22 for Model B. Only 11% of the total number of QTL were identified based on Models A and B, which indicates that both models are complementary. Epistasis was detected only for two out of the eight traits, and contributed only to a minor extent to the genotypic variance. This low relevance of epistasis implies that in sugar beet breeding the prediction of performance of three-way hybrids is feasible with high accuracy based on the means of their single crosses.

  15. A sex-averaged genetic linkage map in coastal Douglas-fir (Pseudotsuga menziesii [Mirb] Franco var menziesii) based on RFLP and RAPD markers

    Science.gov (United States)

    K.D. Jermstad; D.L. Bassoni; N.C. Wheeler; D.B. Neale

    1998-01-01

    We have constructed a sex-averaged genetic linkage map in coastal Douglas-fir ( Pseudotsuga menziesii [Mirb.] Franco var menziesii) using a three-generation outcrossed pedigree and molecular markers. Our research objectives are to learn about genome organization and to identify markers associated with adaptive traits. The map...

  16. A genetic linkage map of the diplosporous chromosomal region in Taraxacum officinale (common dandelion; Asteraceae).

    Science.gov (United States)

    Vijverberg, K; Van Der Hulst, R G M; Lindhout, P; Van Dijk, P J

    2004-02-01

    In this study, we mapped the diplosporous chromosomal region in Taraxacum officinale, by using amplified fragment length polymorphism technology (AFLP) in 73 plants from a segregating population. Taraxacum serves as a model system to investigate the genetics, ecology, and evolution of apomixis. The genus includes sexual diploid as well as apomictic polyploid, mostly triploid, plants. Apomictic Taraxacum is diplosporous, parthenogenetic, and has autonomous endosperm formation. Previous studies have indicated that these three apomixis elements are controlled by more than one locus in Taraxacum and that diplospory inherits as a dominant, monogenic trait ( Ddd; DIP). A bulked segregant analysis provided 34 AFLP markers that were linked to DIP and were, together with two microsatellite markers, used for mapping the trait. The map length was 18.6 cM and markers were found on both sides of DIP, corresponding to 5.9 and 12.7 cM, respectively. None of the markers completely co-segregated with DIP. Eight markers were selected for PCR-based marker development, of which two were successfully converted. In contrast to all other mapping studies of apomeiosis to date, our results showed no evidence for suppression of recombination around the DIP locus in Taraxacum. No obvious evidence for sequence divergence between the DIP and non- DIP homologous loci was found, and no hemizygosity at the DIP locus was detected. These results may indicate that apomixis is relatively recent in Taraxacum.

  17. A saturated genetic linkage map of autotetraploid alfalfa (Medicago sativa L.) developed using genotyping-by-sequencing is highly syntenous with the Medicago truncatula genome.

    Science.gov (United States)

    Li, Xuehui; Wei, Yanling; Acharya, Ananta; Jiang, Qingzhen; Kang, Junmei; Brummer, E Charles

    2014-08-21

    A genetic linkage map is a valuable tool for quantitative trait locus mapping, map-based gene cloning, comparative mapping, and whole-genome assembly. Alfalfa, one of the most important forage crops in the world, is autotetraploid, allogamous, and highly heterozygous, characteristics that have impeded the construction of a high-density linkage map using traditional genetic marker systems. Using genotyping-by-sequencing (GBS), we constructed low-cost, reasonably high-density linkage maps for both maternal and paternal parental genomes of an autotetraploid alfalfa F1 population. The resulting maps contain 3591 single-nucleotide polymorphism markers on 64 linkage groups across both parents, with an average density of one marker per 1.5 and 1.0 cM for the maternal and paternal haplotype maps, respectively. Chromosome assignments were made based on homology of markers to the M. truncatula genome. Four linkage groups representing the four haplotypes of each alfalfa chromosome were assigned to each of the eight Medicago chromosomes in both the maternal and paternal parents. The alfalfa linkage groups were highly syntenous with M. truncatula, and clearly identified the known translocation between Chromosomes 4 and 8. In addition, a small inversion on Chromosome 1 was identified between M. truncatula and M. sativa. GBS enabled us to develop a saturated linkage map for alfalfa that greatly improved genome coverage relative to previous maps and that will facilitate investigation of genome structure. GBS could be used in breeding populations to accelerate molecular breeding in alfalfa. Copyright © 2014 Li et al.

  18. High-density linkage maps fail to detect any genetic component to sex determination in a Rana temporaria family.

    Science.gov (United States)

    Brelsford, A; Rodrigues, N; Perrin, N

    2016-01-01

    Sex chromosome differentiation in Rana temporaria varies strikingly among populations or families: whereas some males display well-differentiated Y haplotypes at microsatellite markers on linkage group 2 (LG2), others are genetically undistinguishable from females. We analysed with RADseq markers one family from a Swiss lowland population with no differentiated sex chromosomes, and where sibship analyses had failed to detect any association between the phenotypic sex of progeny and parental haplotypes. Offspring were reared in a common tank in outdoor conditions and sexed at the froglet stage. We could map a total of 2177 SNPs (1123 in the mother, 1054 in the father), recovering in both adults 13 linkage groups (= chromosome pairs) that were strongly syntenic to Xenopus tropicalis despite > 200 My divergence. Sexes differed strikingly in the localization of crossovers, which were uniformly distributed in the female but limited to chromosome ends in the male. None of the 2177 markers showed significant association with offspring sex. Considering the very high power of our analysis, we conclude that sex determination was not genetic in this family; which factors determined sex remain to be investigated.

  19. Genetic linkage mapping of the dehydroepiandrosterone sulfotransferase (STD) gene on the chromosome 19q13.3 region

    Energy Technology Data Exchange (ETDEWEB)

    Durocher, F.; Morissette, J.; Dufort, I.; Simard, J.; Luu-The, V. [Laval Univ. Quebec (Canada)

    1995-10-10

    In the human liver and adrenal, there is a single hydroxysteroid sulfotransferase, which catalyzes the transformation of dehydroepiandrosterone to dehydroepiandrosterone sulfate, the most abundantly circulating steroid in humans, and also catalyzes the sulfation of a series of other 3{beta}-hydroxysteroids as well as cholesterol. Dehydroepiandrosterone sulfate serves as precursor for the formation of active androgens and estrogens in several peripheral tissues, indicating that hydroxysteroid sulfotransferase plays a pivotal role in controlling the hormonal action of sex steroids by regulating their bioavailability. We recently elucidated the structure of the gene encoding hydroxysteroid sulfotransferase (STD), also designated dehydroepiandrosterone sulfotransferase, which spans 17 kb and contains six exons. The STD gene was preliminarily assigned to chromosome 19 by polymerase chain reaction (PCR) amplification of DNA from a panel of human/rodent somatic cell hybrids. To locate the STD gene, the novel biallelic polymorphism found in intron 2 was genotyped in eight CEPH reference families by direct sequencing of PCR products. Two-point linkage analysis was first performed between the latter polymorphism and chromosome 19 markers from Genethon and NIH/CEPH. The closest linkage was observed with D19S412 (Z{sub max} = 9.23; {theta}{sub max} 0.038) and HRC (Z{sub max} =5.95; {theta}{sub max}0.036), located on the 19q13.3 region. A framework map including six Genethon markers flanking the polymorphic STD gene was created by multipoint linkage analysis. Thereafter, a high-resolution genetic map of the region was constructed, yielding to the following order: qter-D19S414-D19S224-D19S420-D19S217-(APOC2-D19S412)-(STD-HRC)-KLK-D19S22-D19S180-PRKCG-D19S418-tel. 24 refs., 2 figs.

  20. Development and Integration of Genome-Wide Polymorphic Microsatellite Markers onto a Reference Linkage Map for Constructing a High-Density Genetic Map of Chickpea.

    Science.gov (United States)

    Khajuria, Yash Paul; Saxena, Maneesha S; Gaur, Rashmi; Chattopadhyay, Debasis; Jain, Mukesh; Parida, Swarup K; Bhatia, Sabhyata

    2015-01-01

    The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777) of an inter-specific reference mapping population. High amplification efficiency (87%), experimental validation success rate (81%) and polymorphic potential (55%) of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48%) detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than inter-specific polymorphic potential (59%). An advanced, high-density, integrated and inter-specific chickpea genetic map (ICC4958 x PI489777) having 1697 map positions spanning 1061.16 cM with an average inter-marker distance of 0.625 cM was constructed by assigning 634 novel informative transcript-derived and genomic microsatellite markers on eight linkage groups (LGs) of our prior documented, 1063 marker-based genetic map. The constructed genome map identified 88, including four major (7-23 cM) longest high-resolution genomic regions on LGs 3, 5 and 8, where the maximum number of novel genomic and genic microsatellite markers were specifically clustered within 1 cM genetic distance. It was for the first time in chickpea that in silico FLP analysis at genome-wide level was carried out and such a large number of microsatellite markers were identified, experimentally validated and further used in genetic mapping. To best of our knowledge, in the presently constructed genetic map, we mapped highest

  1. Development and Integration of Genome-Wide Polymorphic Microsatellite Markers onto a Reference Linkage Map for Constructing a High-Density Genetic Map of Chickpea.

    Directory of Open Access Journals (Sweden)

    Yash Paul Khajuria

    Full Text Available The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777 of an inter-specific reference mapping population. High amplification efficiency (87%, experimental validation success rate (81% and polymorphic potential (55% of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48% detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than inter-specific polymorphic potential (59%. An advanced, high-density, integrated and inter-specific chickpea genetic map (ICC4958 x PI489777 having 1697 map positions spanning 1061.16 cM with an average inter-marker distance of 0.625 cM was constructed by assigning 634 novel informative transcript-derived and genomic microsatellite markers on eight linkage groups (LGs of our prior documented, 1063 marker-based genetic map. The constructed genome map identified 88, including four major (7-23 cM longest high-resolution genomic regions on LGs 3, 5 and 8, where the maximum number of novel genomic and genic microsatellite markers were specifically clustered within 1 cM genetic distance. It was for the first time in chickpea that in silico FLP analysis at genome-wide level was carried out and such a large number of microsatellite markers were identified, experimentally validated and further used in genetic mapping. To best of our knowledge, in the presently constructed genetic map, we mapped

  2. Development and Integration of Genome-Wide Polymorphic Microsatellite Markers onto a Reference Linkage Map for Constructing a High-Density Genetic Map of Chickpea

    Science.gov (United States)

    Gaur, Rashmi; Chattopadhyay, Debasis; Jain, Mukesh; Parida, Swarup K.; Bhatia, Sabhyata

    2015-01-01

    The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777) of an inter-specific reference mapping population. High amplification efficiency (87%), experimental validation success rate (81%) and polymorphic potential (55%) of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48%) detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than inter-specific polymorphic potential (59%). An advanced, high-density, integrated and inter-specific chickpea genetic map (ICC4958 x PI489777) having 1697 map positions spanning 1061.16 cM with an average inter-marker distance of 0.625 cM was constructed by assigning 634 novel informative transcript-derived and genomic microsatellite markers on eight linkage groups (LGs) of our prior documented, 1063 marker-based genetic map. The constructed genome map identified 88, including four major (7–23 cM) longest high-resolution genomic regions on LGs 3, 5 and 8, where the maximum number of novel genomic and genic microsatellite markers were specifically clustered within 1 cM genetic distance. It was for the first time in chickpea that in silico FLP analysis at genome-wide level was carried out and such a large number of microsatellite markers were identified, experimentally validated and further used in genetic mapping. To best of our knowledge, in the presently constructed genetic map, we mapped highest

  3. Genetic Mapping

    Science.gov (United States)

    ... Fact Sheets Fact Sheets En Español: Mapeo Genético Genetic Mapping What is genetic mapping? How do researchers create ... genetic map? What are genetic markers? What is genetic mapping? Among the main goals of the Human Genome ...

  4. The molecular genetic linkage map of the model legume Medicago truncatula: an essential tool for comparative legume genomics and the isolation of agronomically important genes

    Directory of Open Access Journals (Sweden)

    Ané Jean-Michel

    2002-01-01

    Full Text Available Abstract Background The legume Medicago truncatula has emerged as a model plant for the molecular and genetic dissection of various plant processes involved in rhizobial, mycorrhizal and pathogenic plant-microbe interactions. Aiming to develop essential tools for such genetic approaches, we have established the first genetic map of this species. Two parental homozygous lines were selected from the cultivar Jemalong and from the Algerian natural population (DZA315 on the basis of their molecular and phenotypic polymorphism. Results An F2 segregating population of 124 individuals between these two lines was obtained using an efficient manual crossing technique established for M. truncatula and was used to construct a genetic map. This map spans 1225 cM (average 470 kb/cM and comprises 289 markers including RAPD, AFLP, known genes and isoenzymes arranged in 8 linkage groups (2n = 16. Markers are uniformly distributed throughout the map and segregation distortion is limited to only 3 linkage groups. By mapping a number of common markers, the eight linkage groups are shown to be homologous to those of diploid alfalfa (M. sativa, implying a good level of macrosynteny between the two genomes. Using this M. truncatula map and the derived F3 populations, we were able to map the Mtsym6 symbiotic gene on linkage group 8 and the SPC gene, responsible for the direction of pod coiling, on linkage group 7. Conclusions These results demonstrate that Medicago truncatula is amenable to diploid genetic analysis and they open the way to map-based cloning of symbiotic or other agronomically-important genes using this model plant.

  5. A genetic linkage map for watermelon derived from a testcross population: ( Citrullus lanatus var. citroides x C. lanatus var. lanatus) x Citrullus colocynthis.

    Science.gov (United States)

    Levi, A.; Thomas, E.; Joobeur, T.; Zhang, X.; Davis, A.

    2002-09-01

    A genetic linkage map was constructed for watermelon using a testcross population [Plant Accession Griffin 14113 ( Citrullus lanatus var. citroides) x New Hampshire Midget (NHM; C. lanatus var. lanatus)] x U.S. Plant Introduction (PI) 386015 ( Citrullus colocynthis). The map contains 141 randomly amplified polymorphic DNA (RAPD) markers produced by 78 primers, 27 inter-simple sequence repeat (ISSR) markers produced by 17 primers, and a sequence-characterized amplified region (SCAR) marker that was previously reported as linked (1.6 cM) to race-1 Fusarium wilt [incited by Fusarium oxysporum Schlechtend.:Fr. f. sp. niveum (E.F.Sm.) W.C. Synder & H.N. Hans] resistance in watermelon. The map consists of 25 linkage groups. Among them are a large linkage group that contains 22 markers covering a mapping distance of 225.6 cM and six large groups each with 10-20 markers covering a mapping distance of 68.8 to 110.8 cM. There are five additional linkage groups consisting of 3-7 markers per group, each covering a mapping distance of 36.5 to 57.2 cM. The 13 remaining linkage groups are small, each consisting of 2-11 markers covering a mapping distance of 3.5-29.9 cM. The entire map covers a total distance of 1,166.2 cM with an average distance of 8.1 cM between two markers. This map is useful for the further development of markers linked to disease resistance and watermelon fruit qualities.

  6. Cytogenetic characterization and AFLP-based genetic linkage mapping for the butterfly Bicyclus anynana, covering all 28 karyotyped chromosomes.

    Directory of Open Access Journals (Sweden)

    Arjen E Van't Hof

    Full Text Available BACKGROUND: The chromosome characteristics of the butterfly Bicyclus anynana, have received little attention, despite the scientific importance of this species. This study presents the characterization of chromosomes in this species by means of cytogenetic analysis and linkage mapping. METHODOLOGY/PRINCIPAL FINDINGS: Physical genomic features in the butterfly B. anynana were examined by karyotype analysis and construction of a linkage map. Lepidoptera possess a female heterogametic W-Z sex chromosome system. The WZ-bivalent in pachytene oocytes of B. anynana consists of an abnormally small, heterochromatic W-chromosome with the Z-chromosome wrapped around it. Accordingly, the W-body in interphase nuclei is much smaller than usual in Lepidoptera. This suggests an intermediate stage in the process of secondary loss of the W-chromosome to a ZZ/Z sex determination system. Two nucleoli are present in the pachytene stage associated with an autosome and the WZ-bivalent respectively. Chromosome counts confirmed a haploid number of n = 28. Linkage mapping had to take account of absence of crossing-over in females, and of our use of a full-sib crossing design. We developed a new method to determine and exclude the non-recombinant uninformative female inherited component in offspring. The linkage map was constructed using a novel approach that uses exclusively JOINMAP-software for Lepidoptera linkage mapping. This approach simplifies the mapping procedure, avoids over-estimation of mapping distance and increases the reliability of relative marker positions. A total of 347 AFLP markers, 9 microsatellites and one single-copy nuclear gene covered all 28 chromosomes, with a mapping distance of 1354 cM. Conserved synteny of Tpi on the Z-chromosome in Lepidoptera was confirmed for B. anynana. The results are discussed in relation to other mapping studies in Lepidoptera. CONCLUSIONS/SIGNIFICANCE: This study adds to the knowledge of chromosome structure and

  7. Construction of integrated genetic linkage maps of the tiger shrimp (Penaeus monodon) using microsatellite and AFLP markers.

    Science.gov (United States)

    You, E-M; Liu, K-F; Huang, S-W; Chen, M; Groumellec, M L; Fann, S-J; Yu, H-T

    2010-08-01

    The linkage maps of male and female tiger shrimp (P. monodon) were constructed based on 256 microsatellite and 85 amplified fragment length polymorphism (AFLP) markers. Microsatellite markers obtained from clone sequences of partial genomic libraries, tandem repeat sequences from databases and previous publications and fosmid end sequences were employed. Of 670 microsatellite and 158 AFLP markers tested for polymorphism, 341 (256 microsatellite and 85 AFLP markers) were used for genotyping with three F(1) mapping panels, each comprising two parents and more than 100 progeny. Chi-square goodness-of-fit test (chi(2)) revealed that only 19 microsatellite and 28 AFLP markers showed a highly significant segregation distortion (P every approximately 11.2 cM, with an observed genome length of 2033.4 cM. The female map consisted of 171 microsatellite and 36 AFLP markers spaced every approximately 13.8 cM, with an observed genome length of 2182 cM. Both maps shared 136 microsatellite markers, and the alignment between them indicated 38 homologous pairs of linkage groups including the linkage group representing the sex chromosome. The karyotype of P. monodon is also presented. The tentative assignment of the 44 pairs of P. monodon haploid chromosomes showed the composition of forty metacentric, one submetacentric and three acrocentric chromosomes. Our maps provided a solid foundation for gene and QTL mapping in the tiger shrimp.

  8. A genetic linkage map of willow (Salix viminalis) based on AFLP and microsatelite markers

    NARCIS (Netherlands)

    Hanley, S.; Barker, J.H.A.; Ooijen, van J.W.; Aldam, C.; Harris, S.L.; Ahman, I.; Larsson, S.; Karp, A.

    2002-01-01

    The genus Salix (willow) contains a number of species of great value as biomass crops. Efforts to breed varieties with improved biomass yields and resistances to pests and diseases are limited by the lack of knowledge on the genetic basis of the traits. We have used AFLP and microsatellite markers t

  9. A first AFLP-based genetic linkage map for brine shrimp Artemia franciscana and its application in mapping the sex locus.

    Science.gov (United States)

    De Vos, Stephanie; Bossier, Peter; Van Stappen, Gilbert; Vercauteren, Ilse; Sorgeloos, Patrick; Vuylsteke, Marnik

    2013-01-01

    We report on the construction of sex-specific linkage maps, the identification of sex-linked markers and the genome size estimation for the brine shrimp Artemia franciscana. Overall, from the analysis of 433 AFLP markers segregating in a 112 full-sib family we identified 21 male and 22 female linkage groups (2n = 42), covering 1,041 and 1,313 cM respectively. Fifteen putatively homologous linkage groups, including the sex linkage groups, were identified between the female and male linkage map. Eight sex-linked AFLP marker alleles were inherited from the female parent, supporting the hypothesis of a WZ-ZZ sex-determining system. The haploid Artemia genome size was estimated to 0.93 Gb by flow cytometry. The produced Artemia linkage maps provide the basis for further fine mapping and exploring of the sex-determining region and are a possible marker resource for mapping genomic loci underlying phenotypic differences among Artemia species.

  10. High-resolution genetic linkage mapping, high-temperature tolerance and growth-related quantitative trait locus (QTL) identification in Marsupenaeus japonicus.

    Science.gov (United States)

    Lu, Xia; Luan, Sheng; Hu, Long Yang; Mao, Yong; Tao, Ye; Zhong, Sheng Ping; Kong, Jie

    2016-06-01

    The Kuruma prawn, Marsupenaeus japonicus, is one of the most promising marine invertebrates in the industry in Asia, Europe and Australia. However, the increasing global temperatures result in considerable economic losses in M. japonicus farming. In the present study, to select genetically improved animals for the sustainable development of the Kuruma prawn industry, a high-resolution genetic linkage map and quantitative trait locus (QTL) identification were performed using the RAD technology. The maternal map contained 5849 SNP markers and spanned 3127.23 cM, with an average marker interval of 0.535 cM. Instead, the paternal map contained 3927 SNP markers and spanned 3326.19 cM, with an average marker interval of 0.847 cM. The consensus map contained 9289 SNP markers and spanned 3610.90 cM, with an average marker interval of 0.388 cM and coverage of 99.06 % of the genome. The markers were grouped into 41 linkage groups in the maps. Significantly, negative correlation was detected between high-temperature tolerance (UTT) and body weight (BW). The QTL mapping revealed 129 significant QTL loci for UTT and four significant QTL loci for BW at the genome-wide significance threshold. Among these QTLs, 129 overlapped with linked SNPs, and the remaining four were located in regions between contiguous SNPs. They explained the total phenotypic variance ranging from 8.9 to 12.4 %. Because of a significantly negative correlation between growth and high-temperature tolerance, we demonstrate that this high-resolution linkage map and QTLs would be useful for further marker-assisted selection in the genetic improvement of M. japonicus.

  11. A Linkage Learning Genetic Algorithm with Linkage Matrix

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The goal of linkage learning, or building block identification, is the creation of a more effective Genetic Algorithm (GA). This paper proposes a new Linkage Learning Genetic Algorithms, named m-LLGA. With the linkage learning module and the linkage-based genetic operation, m-LLGA is not only able to learn and record the linkage information among genes without any prior knowledge of the function being optimized. It also can use the linkage information stored in the linkage matrix to guide the selection of crossover point. The preliminary experiments on two kinds of bounded difficulty problems and a TSP problem validated the performance of m-LLGA. The m-LLGA learns the linkage of different building blocks parallel and therefore solves these problems effectively; it can also reasonably reduce the probability of building blocks being disrupted by crossover at the same time give attention to getting away from local minimum.

  12. Genetic structure, linkage disequilibrium and association mapping of Verticillium wilt resistance in elite cotton (Gossypium hirsutum L.) germplasm population.

    Science.gov (United States)

    Zhao, Yunlei; Wang, Hongmei; Chen, Wei; Li, Yunhai

    2014-01-01

    Understanding the population structure and linkage disequilibrium in an association panel can effectively avoid spurious associations and improve the accuracy in association mapping. In this study, one hundred and fifty eight elite cotton (Gossypium hirsutum L.) germplasm from all over the world, which were genotyped with 212 whole genome-wide marker loci and phenotyped with an disease nursery and greenhouse screening method, were assayed for population structure, linkage disequilibrium, and association mapping of Verticillium wilt resistance. A total of 480 alleles ranging from 2 to 4 per locus were identified from all collections. Model-based analysis identified two groups (G1 and G2) and seven subgroups (G1a-c, G2a-d), and differentiation analysis showed that subgroup having a single origin or pedigree was apt to differentiate with those having a mixed origin. Only 8.12% linked marker pairs showed significant LD (Pmapping, which widely were distributed among 15 chromosomes. Among which 10 marker loci were found to be consistent with previously identified QTLs and 32 were new unreported marker loci, and QTL clusters for Verticillium wilt resistanc on Chr.16 were also proved in our study, which was consistent with the strong linkage in this chromosome. Our results would contribute to association mapping and supply the marker candidates for marker-assisted selection of Verticillium wilt resistance in cotton.

  13. Construction of an intra-specific sweet cherry (Prunus avium L.) genetic linkage map and synteny analysis with the Prunus reference map

    Science.gov (United States)

    Linkage maps of the sweet cherry cultivar ‘Emperor Francis’ (EF) and the wild forest cherry ‘New York 54’ (NY) were constructed using primarily simple sequence repeat (SSR) markers and gene-derived markers with known positions on the Prunus reference map. The success rate for identifying SSR markers...

  14. A wheat intervarietal genetic linkage map based on microsatellite and target region amplified polymorphism markers and its utility for detecting quantitative trait loci.

    Science.gov (United States)

    Liu, Z H; Anderson, J A; Hu, J; Friesen, T L; Rasmussen, J B; Faris, J D

    2005-08-01

    Efficient user-friendly methods for mapping plant genomes are highly desirable for the identification of quantitative trait loci (QTLs), genotypic profiling, genomic studies, and marker-assisted selection. SSR (microsatellite) markers are user-friendly and efficient in detecting polymorphism, but they detect few loci. Target region amplification polymorphism (TRAP) is a relatively new PCR-based technique that detects a large number of loci from a single reaction without extensive pre-PCR processing of samples. In the investigation reported here, we used both SSRs and TRAPs to generate over 700 markers for the construction of a genetic linkage map in a hard red spring wheat intervarietal recombinant inbred population. A framework map consisting of 352 markers accounted for 3,045 cM with an average density of one marker per 8.7 cM. On average, SSRs detected 1.9 polymorphic loci per reaction, while TRAPs detected 24. Both marker systems were suitable for assigning linkage groups to chromosomes using wheat aneuploid stocks. We demonstrated the utility of the maps by identifying major QTLs for days to heading and reduced plant height on chromosomes 5A and 4B, respectively. Our results indicate that TRAPs are highly efficient for genetic mapping in wheat. The maps developed will be useful for the identification of quality and disease resistance QTLs that segregate in this population.

  15. The first-generation Daphnia magna linkage map

    Directory of Open Access Journals (Sweden)

    De Meester Luc

    2010-09-01

    Full Text Available Abstract Background Daphnia magna is a well-established model species in ecotoxicology, ecology and evolution. Several new genomics tools are presently under development for this species; among them, a linkage map is a first requirement for estimating the genetic background of phenotypic traits in quantitative trait loci (QTL studies and is also very useful in assembling the genome. It also enables comparative studies between D. magna and D. pulex, for which a linkage map already exists. Results Here we describe the first genetic linkage map of D. magna. We generated 214 F2 (intercross clonal lines as the foundation of the linkage analysis. The linkage map itself is based on 109 microsatellite markers, which produced ten major linkage groups ranging in size from 31.1 cM to 288.5 cM. The total size of this linkage map extends to 1211.6 Kosambi cM, and the average interval for the markers within linkage groups is 15.1 cM. The F2 clones can be used to map QTLs for traits that differ between the parental clones. We successfully mapped the location of two loci with infertility alleles, one inherited from the paternal clone (Iinb1 and the other from the maternal clone (Xinb3. Conclusions The D. magna linkage map presented here provides extensive coverage of the genome and a given density of markers that enable us to detect QTLs of moderate to strong effects. It is similar in size to the linkage map of D. pulex.

  16. Classical and molecular genetic mapping

    Science.gov (United States)

    A brief history of classical genetic mapping in soybean [Glycine max (L.) Merr.] is described. Detailed descriptions are given of the development of molecular genetic linkage maps based upon various types of DNA markers Like many plant and animal species, the first molecular map of soybean was bas...

  17. Microsatellites for the genus Cucurbita and an SSR-based genetic linkage map of Cucurbita pepo L.

    Science.gov (United States)

    Gong, L; Stift, G; Kofler, R; Pachner, M; Lelley, T

    2008-06-01

    Until recently, only a few microsatellites have been available for Cucurbita, thus their development is highly desirable. The Austrian oil-pumpkin variety Gleisdorfer Olkürbis (C. pepo subsp. pepo) and the C. moschata cultivar Soler (Puerto Rico) were used for SSR development. SSR-enriched partial genomic libraries were established and 2,400 clones were sequenced. Of these 1,058 (44%) contained an SSR at least four repeats long. Primers were designed for 532 SSRs; 500 primer pairs produced fragments of expected size. Of these, 405 (81%) amplified polymorphic fragments in a set of 12 genotypes: three C. moschata, one C. ecuadorensis, and eight C. pepo representing all eight cultivar groups. On an average, C. pepo and C. moschata produced 3.3 alleles per primer pair, showing high inter-species transferability. There were 187 SSR markers detecting polymorphism between the USA oil-pumpkin variety "Lady Godiva" (O5) and the Italian crookneck variety "Bianco Friulano" (CN), which are the parents of our previous F(2) mapping population. It has been used to construct the first published C. pepo map, containing mainly RAPD and AFLP markers. Now the updated map comprises 178 SSRs, 244 AFLPs, 230 RAPDs, five SCARs, and two morphological traits (h and B). It contains 20 linkage groups with a map density of 2.9 cM. The observed genome coverage (Co) is 86.8%.

  18. A new genetic linkage map of tomato based on a Solanum lycopersicum x S. pimpinellifolium RIL population displaying locations of candidate pathogen response genes.

    Science.gov (United States)

    Ashrafi, Hamid; Kinkade, Matthew; Foolad, Majid R

    2009-11-01

    The narrow genetic base of the cultivated tomato, Solanum lycopersicum L., necessitates introgression of new variation from related species. Wild tomato species represent a rich source of useful genes and traits. Exploitation of genetic variation within wild species can be facilitated by the use of molecular markers and genetic maps. Recently we identified an accession (LA2093) within the red-fruited wild tomato species Solanum pimpinellifolium L. with exceptionally desirable characteristics, including disease resistance, abiotic stress tolerance, and high fruit lycopene content. To facilitate genetic characterization of such traits and their exploitation in tomato crop improvement, we developed a new recombinant inbred line (RIL) population from a cross between LA2093 and an advanced tomato breeding line (NCEBR-1). Furthermore, we constructed a medium-density molecular linkage map of this population using 294 polymorphic markers, including standard RFLPs, EST sequences (used as RFLP probes), CAPS, and SSRs. The map spanned 1091 cM of the tomato genome with an average marker spacing of 3.7 cM. A majority of the EST sequences, which were mainly chosen based on the putative role of their unigenes in disease resistance, defense-related response, or fruit quality, were mapped onto the tomato chromosomes for the first time. Co-localizations of relevant EST sequences with known disease resistance genes in tomato were also examined. This map will facilitate identification, genetic exploitation, and positional cloning of important genes or quantitative trait loci in LA2093. It also will allow the elucidation of the molecular mechanism(s) underlying important traits segregating in the RIL population. The map may further facilitate characterization and exploitation of genetic variation in other S. pimpinellifolium accessions as well as in modern cultivars of tomato.

  19. Methods for genetic linkage analysis using trisomies

    Energy Technology Data Exchange (ETDEWEB)

    Feingold, E. [Emory Univ. School of Public Health, Atlanta, GA (United States); Lamb, N.E.; Sherman, S.L. [Emory Univ., Atlanta, GA (United States)

    1995-02-01

    Certain genetic disorders are rare in the general population, but more common in individuals with specific trisomies. Examples of this include leukemia and duodenal atresia in trisomy 21. This paper presents a linkage analysis method for using trisomic individuals to map genes for such traits. It is based on a very general gene-specific dosage model that posits that the trait is caused by specific effects of different alleles at one or a few loci and that duplicate copies of {open_quotes}susceptibility{close_quotes} alleles inherited from the nondisjoining parent give increased likelihood of having the trait. Our mapping method is similar to identity-by-descent-based mapping methods using affected relative pairs and also to methods for mapping recessive traits using inbred individuals by looking for markers with greater than expected homozygosity by descent. In the trisomy case, one would take trisomic individuals and look for markers with greater than expected homozygosity in the chromosomes inherited from the nondisjoining parent. We present statistical methods for performing such a linkage analysis, including a test for linkage to a marker, a method for estimating the distance from the marker to the trait gene, a confidence interval for that distance, and methods for computing power and sample sizes. We also resolve some practical issues involved in implementing the methods, including how to use partially informative markers and how to test candidate genes. 20 refs., 5 figs., 1 tab.

  20. A complete genetic linkage map and QTL analyses for bast fibre quality traits, yield and yield components in jute (Corchorus olitorius L.).

    Science.gov (United States)

    Topdar, N; Kundu, A; Sinha, M K; Sarkar, D; Das, M; Banerjee, S; Kar, C S; Satya, P; Balyan, H S; Mahapatra, B S; Gupta, P K

    2013-01-01

    We report the first complete microsatellite genetic map of jute (Corchorus olitorius L.; 2n = 2x = 14) using an F6 recombinant inbred population. Of the 403 microsatellite markers screened, 82 were mapped on the seven linkage groups (LGs) that covered a total genetic distance of 799.9 cM, with an average marker interval of 10.7 cM. LG5 had the longest and LG7 the shortest genetic lengths, whereas LG1 had the maximum and LG7 the minimum number of markers. Segregation distortion of microsatellite loci was high (61%), with the majority of them (76%) skewed towards the female parent. Genomewide non-parametric single-marker analysis in combination with multiple quantitative trait loci (QTL)-models (MQM) mapping detected 26 definitive QTLs for bast fibre quality, yield and yield-related traits. These were unevenly distributed on six LGs, as colocalized clusters, at genomic sectors marked by 15 microsatellite loci. LG1 was the QTL-richest map sector, with the densest colocalized clusters of QTLs governing fibre yield, yield-related traits and tensile strength. Expectedly, favorable QTLs were derived from the desirable parents, except for nearly all of those of fibre fineness, which might be due to the creation of new gene combinations. Our results will be a good starting point for further genome analyses in jute.

  1. Genetic Mapping in Human Disease

    OpenAIRE

    Altshuler, David; Daly, Mark J; Lander, Eric S.

    2008-01-01

    Genetic mapping provides a powerful approach to identify genes and biological processes underlying any trait influenced by inheritance, including human diseases. We discuss the intellectual foundations of genetic mapping of Mendelian and complex traits in humans, examine lessons emerging from linkage analysis of Mendelian diseases and genome-wide association studies of common diseases, and discuss questions and challenges that lie ahead.

  2. A genetic linkage map of Phaseolus vulgaris L. and localization of genes for specific resistance to six races of anthracnose (Colletotrichum lindemuthianum).

    Science.gov (United States)

    Rodríguez-Suárez, Cristina; Méndez-Vigo, Belén; Pañeda, Astrid; Ferreira, Juan José; Giraldez, Ramón

    2007-02-01

    A genetic map of common bean was constructed using 197 markers including 152 RAPDs, 32 RFLPs, 12 SCARs, and 1 morphological marker. The map was established by using a F(2) population of 85 individuals from the cross between a line derived from the Spanish landrace Andecha (Andean origin) and the Mesoamerican genotype A252. The resulting map covers about 1,401.9 cM, with an average marker distance of 7.1 cM and includes molecular markers linked to disease resistance genes for anthracnose, bean common mosaic virus, bean golden yellow mosaic virus, common bacterial blight, and rust. Resistance to races 6, 31, 38, 39, 65, and 357 of the pathogenic fungus Colletotrichum lindemuthianum (anthracnose) was evaluated in F(3) families derived from the corresponding F(2) individuals. The intermediate resistance to race 65 proceeding from Andecha can be explained by a single dominant gene located on linkage group B1, corresponding to the Co-1 gene. The recombination between the resistance specificities proceeding from A252 agrees with the assumption that total resistance to races 6, 31, 38, 39, 65, and 357, is organized in two clusters. One cluster, located on B4 linkage group, includes individual genes for specific resistance to races 6, 38, 39, and 357. The second cluster is located on linkage group B11 and includes individual genes for specific resistance to races 6, 31, 38, 39, and 65. These two clusters correspond to genes Co-3/Co-9 and Co-2, respectively. It is concluded that most anthracnose resistance Co- genes, previously described as single major genes conferring resistance to several races, could be organized as clusters of different genes conferring race-specific resistance.

  3. Structure, evolution, and comparative genomics of tetraploid cotton based on a high-density genetic linkage map.

    Science.gov (United States)

    Li, Ximei; Jin, Xin; Wang, Hantao; Zhang, Xianlong; Lin, Zhongxu

    2016-06-01

    A high-density linkage map was constructed using 1,885 newly obtained loci and 3,747 previously published loci, which included 5,152 loci with 4696.03 cM in total length and 0.91 cM in mean distance. Homology analysis in the cotton genome further confirmed the 13 expected homologous chromosome pairs and revealed an obvious inversion on Chr10 or Chr20 and repeated inversions on Chr07 or Chr16. In addition, two reciprocal translocations between Chr02 and Chr03 and between Chr04 and Chr05 were confirmed. Comparative genomics between the tetraploid cotton and the diploid cottons showed that no major structural changes exist between DT and D chromosomes but rather between AT and A chromosomes. Blast analysis between the tetraploid cotton genome and the mixed genome of two diploid cottons showed that most AD chromosomes, regardless of whether it is from the AT or DT genome, preferentially matched with the corresponding homologous chromosome in the diploid A genome, and then the corresponding homologous chromosome in the diploid D genome, indicating that the diploid D genome underwent converted evolution by the diploid A genome to form the DT genome during polyploidization. In addition, the results reflected that a series of chromosomal translocations occurred among Chr01/Chr15, Chr02/Chr14, Chr03/Chr17, Chr04/Chr22, and Chr05/Chr19.

  4. AFLP linkage map of the Japanese quail Coturnix japonica

    Directory of Open Access Journals (Sweden)

    Beaumont Catherine

    2003-09-01

    Full Text Available Abstract The quail is a valuable farm and laboratory animal. Yet molecular information about this species remains scarce. We present here the first genetic linkage map of the Japanese quail. This comprehensive map is based solely on amplified fragment length polymorphism (AFLP markers. These markers were developed and genotyped in an F2 progeny from a cross between two lines of quail differing in stress reactivity. A total of 432 polymorphic AFLP markers were detected with 24 TaqI/EcoRI primer combinations. On average, 18 markers were produced per primer combination. Two hundred and fifty eight of the polymorphic markers were assigned to 39 autosomal linkage groups plus the ZW sex chromosome linkage groups. The linkage groups range from 2 to 28 markers and from 0.0 to 195.5 cM. The AFLP map covers a total length of 1516 cM, with an average genetic distance between two consecutive markers of 7.6 cM. This AFLP map can be enriched with other marker types, especially mapped chicken genes that will enable to link the maps of both species and make use of the powerful comparative mapping approach. This AFLP map of the Japanese quail already provides an efficient tool for quantitative trait loci (QTL mapping.

  5. The Barley Chromosome 5 Linkage Map

    DEFF Research Database (Denmark)

    Jensen, J.; Jørgensen, Jørgen Helms

    1975-01-01

    : wst5 (white streaks), necl (necrotic leaf spots), Ml-nn (powdery mildew resistance), and Pa4 (leaf rust resistance). Further, the two sections of the map are united, and the precision of the map is improved. A system for designating the positions of the loci on the linkage map is proposed. A 0...

  6. An expanded genetic linkage map of an intervarietal Agaricus bisporus var. bisporusxA. bisporus var. burnettii hybrid based on AFLP, SSR and CAPS markers sheds light on the recombination behaviour of the species.

    Science.gov (United States)

    Foulongne-Oriol, Marie; Spataro, Cathy; Cathalot, Vincent; Monllor, Sarah; Savoie, Jean-Michel

    2010-03-01

    A genetic linkage map for the edible basidiomycete Agaricus bisporus was constructed from 118 haploid homokaryons derived from an intervarietal A. bisporus var. bisporus x A. bisporus var. burnettii hybrid. Two hundred and thirty-one AFLP, 21 SSR, 68 CAPS markers together with the MAT, BSN, PPC1 loci and one allozyme locus (ADH) were evenly spread over 13 linkage groups corresponding to the chromosomes of A. bisporus. The map covers 1156cM, with an average marker spacing of 3.9cM and encompasses nearly the whole genome. The average number of crossovers per chromosome per individual is 0.86. Normal recombination over the entire genome occurs in the heterothallic variety, burnettii, contrary to the homothallic variety, bisporus, which showed adaptive genome-wide suppressed recombination. This first comprehensive genetic linkage map for A. bisporus provides foundations for quantitative trait analyses and breeding programme monitoring, as well as genome organisation studies.

  7. Software for analysis and manipulation of genetic linkage data.

    Science.gov (United States)

    Weaver, R; Helms, C; Mishra, S K; Donis-Keller, H

    1992-06-01

    We present eight computer programs written in the C programming language that are designed to analyze genotypic data and to support existing software used to construct genetic linkage maps. Although each program has a unique purpose, they all share the common goals of affording a greater understanding of genetic linkage data and of automating tasks to make computers more effective tools for map building. The PIC/HET and FAMINFO programs automate calculation of relevant quantities such as heterozygosity, PIC, allele frequencies, and informativeness of markers and pedigrees. PREINPUT simplifies data submissions to the Centre d'Etude du Polymorphisme Humain (CEPH) data base by creating a file with genotype assignments that CEPH's INPUT program would otherwise require to be input manually. INHERIT is a program written specifically for mapping the X chromosome: by assigning a dummy allele to males, in the nonpseudoautosomal region, it eliminates falsely perceived noninheritances in the data set. The remaining four programs complement the previously published genetic linkage mapping software CRI-MAP and LINKAGE. TWOTABLE produces a more readable format for the output of CRI-MAP two-point calculations; UNMERGE is the converse to CRI-MAP's merge option; and GENLINK and LINKGEN automatically convert between the genotypic data file formats required by these packages. All eight applications read input from the same types of data files that are used by CRI-MAP and LINKAGE. Their use has simplified the management of data, has increased knowledge of the content of information in pedigrees, and has reduced the amount of time needed to construct genetic linkage maps of chromosomes.

  8. Duck (Anas platyrhynchos) linkage mapping by AFLP fingerprinting.

    Science.gov (United States)

    Huang, Chang-Wen; Cheng, Yu-Shin; Rouvier, Roger; Yang, Kuo-Tai; Wu, Chean-Ping; Huang, Hsiu-Lin; Huang, Mu-Chiou

    2009-03-17

    Amplified fragment length polymorphism (AFLP) with multicolored fluorescent molecular markers was used to analyze duck (Anas platyrhynchos) genomic DNA and to construct the first AFLP genetic linkage map. These markers were developed and genotyped in 766 F2 individuals from six families from a cross between two different selected duck lines, brown Tsaiya and Pekin. Two hundred and ninety-six polymorphic bands (64% of all bands) were detected using 18 pairs of fluorescent TaqI/EcoRI primer combinations. Each primer set produced a range of 7 to 29 fragments in the reactions, and generated on average 16.4 polymorphic bands. The AFLP linkage map included 260 co-dominant markers distributed in 32 linkage groups. Twenty-one co-dominant markers were not linked with any other marker. Each linkage group contained three to 63 molecular markers and their size ranged between 19.0 cM and 171.9 cM. This AFLP linkage map provides important information for establishing a duck chromosome map, for mapping quantitative trait loci (QTL mapping) and for breeding applications.

  9. Duck (Anas platyrhynchos linkage mapping by AFLP fingerprinting

    Directory of Open Access Journals (Sweden)

    Yang Kuo-Tai

    2009-03-01

    Full Text Available Abstract Amplified fragment length polymorphism (AFLP with multicolored fluorescent molecular markers was used to analyze duck (Anas platyrhynchos genomic DNA and to construct the first AFLP genetic linkage map. These markers were developed and genotyped in 766 F2 individuals from six families from a cross between two different selected duck lines, brown Tsaiya and Pekin. Two hundred and ninety-six polymorphic bands (64% of all bands were detected using 18 pairs of fluorescent TaqI/EcoRI primer combinations. Each primer set produced a range of 7 to 29 fragments in the reactions, and generated on average 16.4 polymorphic bands. The AFLP linkage map included 260 co-dominant markers distributed in 32 linkage groups. Twenty-one co-dominant markers were not linked with any other marker. Each linkage group contained three to 63 molecular markers and their size ranged between 19.0 cM and 171.9 cM. This AFLP linkage map provides important information for establishing a duck chromosome map, for mapping quantitative trait loci (QTL mapping and for breeding applications.

  10. Methods for genetic linkage analysis using trisomies

    Energy Technology Data Exchange (ETDEWEB)

    Feingold, E.; Lamb, N.E.; Sherman, S.L. [Emory Univ., Atlanta, GA (United States)

    1994-09-01

    Certain genetic disorders (e.g. congenital cataracts, duodenal atresia) are rare in the general population, but more common in people with Down`s syndrome. We present a method for using individuals with trisomy 21 to map genes for such traits. Our methods are analogous to methods for mapping autosomal dominant traits using affected relative pairs by looking for markers with greater than expected identity-by-descent. In the trisomy case, one would take trisomic individuals and look for markers with greater than expected reduction to homozygosity in the chromosomes inherited form the non-disjoining parent. We present statistical methods for performing such a linkage analysis, including a test for linkage to a marker, a method for estimating the distance from the marker to the gene, a confidence interval for that distance, and methods for computing power and sample sizes. The methods are described in the context of gene-dosage model for the etiology of the disorder, but can be extended to other models. We also resolve some practical issues involved in implementing the methods, including how to use partially informative markers, how to test candidate genes, and how to handle the effect of reduced recombination associated with maternal meiosis I non-disjunction.

  11. Genetic characterization and linkage disequilibrium mapping of resistance to gray leaf spot in maize(Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    Liyu; Shi; Xiangling; Lv; Jianfeng; Weng; Hanyong; Zhu; Changlin; Liu; Zhuanfang; Hao; Yu; Zhou; Degui; Zhang; Mingshun; Li; Xiaoke; Ci; Xinhai; Li; Shihuang; Zhang

    2014-01-01

    Gray leaf spot(GLS),caused by Cercospora zeae-maydis,is an important foliar disease of maize(Zea mays L.)worldwide,resistance to which is controlled by multiple quantitative trait loci(QTL).To gain insights into the genetic architecture underlying the resistance to this disease,an association mapping population consisting of 161 inbred lines was evaluated for resistance to GLS in a plant pathology nursery at Shenyang in 2010 and 2011.Subsequently,a genome-wide association study,using 41,101 single-nucleotide polymorphisms(SNPs),identified 51 SNPs significantly(P<0.001)associated with GLS resistance,which could be converted into 31 QTL.In addition,three candidate genes related to plant defense were identified,including nucleotidebinding-site/leucine-rich repeat,receptor-like kinase genes similar to those involved in basal defense.Two genic SNPs,PZE-103142893 and PZE-109119001,associated with GLS resistance in chromosome bins 3.07 and 9.07,can be used for marker-assisted selection(MAS)of GLS resistance.These results provide an important resource for developing molecular markers closely linked with the target trait,enhancing breeding efficiency.

  12. Saturation of an intra-gene pool linkage map: towards a unified consensus linkage map for fine mapping and synteny analysis in common bean.

    Science.gov (United States)

    Galeano, Carlos H; Fernandez, Andrea C; Franco-Herrera, Natalia; Cichy, Karen A; McClean, Phillip E; Vanderleyden, Jos; Blair, Matthew W

    2011-01-01

    Map-based cloning and fine mapping to find genes of interest and marker assisted selection (MAS) requires good genetic maps with reproducible markers. In this study, we saturated the linkage map of the intra-gene pool population of common bean DOR364 × BAT477 (DB) by evaluating 2,706 molecular markers including SSR, SNP, and gene-based markers. On average the polymorphism rate was 7.7% due to the narrow genetic base between the parents. The DB linkage map consisted of 291 markers with a total map length of 1,788 cM. A consensus map was built using the core mapping populations derived from inter-gene pool crosses: DOR364 × G19833 (DG) and BAT93 × JALO EEP558 (BJ). The consensus map consisted of a total of 1,010 markers mapped, with a total map length of 2,041 cM across 11 linkage groups. On average, each linkage group on the consensus map contained 91 markers of which 83% were single copy markers. Finally, a synteny analysis was carried out using our highly saturated consensus maps compared with the soybean pseudo-chromosome assembly. A total of 772 marker sequences were compared with the soybean genome. A total of 44 syntenic blocks were identified. The linkage group Pv6 presented the most diverse pattern of synteny with seven syntenic blocks, and Pv9 showed the most consistent relations with soybean with just two syntenic blocks. Additionally, a co-linear analysis using common bean transcript map information against soybean coding sequences (CDS) revealed the relationship with 787 soybean genes. The common bean consensus map has allowed us to map a larger number of markers, to obtain a more complete coverage of the common bean genome. Our results, combined with synteny relationships provide tools to increase marker density in selected genomic regions to identify closely linked polymorphic markers for indirect selection, fine mapping or for positional cloning.

  13. Assembly of the Genome of the Disease Vector Aedes aegypti onto a Genetic Linkage Map Allows Mapping of Genes Affecting Disease Transmission

    KAUST Repository

    Juneja, Punita

    2014-01-30

    The mosquito Aedes aegypti transmits some of the most important human arboviruses, including dengue, yellow fever and chikungunya viruses. It has a large genome containing many repetitive sequences, which has resulted in the genome being poorly assembled - there are 4,758 scaffolds, few of which have been assigned to a chromosome. To allow the mapping of genes affecting disease transmission, we have improved the genome assembly by scoring a large number of SNPs in recombinant progeny from a cross between two strains of Ae. aegypti, and used these to generate a genetic map. This revealed a high rate of misassemblies in the current genome, where, for example, sequences from different chromosomes were found on the same scaffold. Once these were corrected, we were able to assign 60% of the genome sequence to chromosomes and approximately order the scaffolds along the chromosome. We found that there are very large regions of suppressed recombination around the centromeres, which can extend to as much as 47% of the chromosome. To illustrate the utility of this new genome assembly, we mapped a gene that makes Ae. aegypti resistant to the human parasite Brugia malayi, and generated a list of candidate genes that could be affecting the trait. © 2014 Juneja et al.

  14. Conversion of chromosome-specific RAPDs into SCAR-based anchor markers for onion linkage maps and its application to genetic analyses inother Allium species

    NARCIS (Netherlands)

    Masuzaki, S.; Miyazaki, T.; McCallum, J.; Heusden, van A.W.; Kik, C.; Yamashita, K.; Tashiro, Y.

    2008-01-01

    Integration of previously developed Allium cepa linkage maps requires the availability of anchor markers for each of the eight chromosomes of shallot (A. cepa L. common group Aggregatum). To this end, eight RAPD markers originating from our previous research were converted into SCAR markers via clon

  15. Joint-linkage mapping and GWAS reveal extensive genetic loci that regulate male inflorescence size in maize

    Science.gov (United States)

    Both insufficient and excessive male inflorescence size leads to a reduction in maize yield. Knowledge of the genetic architecture of male inflorescence is essential to achieve the optimum inflorescence size for maize breeding. In this study, we used approximately eight thousand inbreds, including b...

  16. EBL-1, a putative erythrocyte binding protein of Plasmodium falciparum, maps within a favored linkage group in two genetic crosses.

    Science.gov (United States)

    Peterson, D S; Wellems, T E

    2000-01-05

    The Duffy binding-like (DBL) superfamily of Plasmodium falciparum encompasses genes which encode ligands for host cell receptors. This superfamily includes two distinct groups of genes, the var genes which encode antigenically variant cytoadherence proteins (PfEMP1), and the eba-175 gene which encodes a glycophorin A binding protein involved in erythrocyte invasion. Here we describe another DBL superfamily member related to eba-175, the ebl-1 gene. Like the eba-175 gene, ebl-1 is a single copy gene encoding DBL domains that have sequences and an overall arrangement distinct from var genes. The inheritance of ebl-1 was found to be strongly favored in two genetic crosses in which one parental clone lacked a chromosome segment carrying the gene. A proliferation phenotype has been previously linked to the same chromosome segment in the first genetic cross. These results suggest that ebl-1 and eba-175 are related members of a multigene family involved in the invasion of erythrocytes by P. falciparum.

  17. A molecular genetic linkage map of mouse chromosome 18, including spm, Grl-1, Fim-2/c-fms, and Mbp.

    Science.gov (United States)

    Sakai, Y; Miyawaki, S; Shimizu, A; Ohno, K; Watanabe, T

    1991-02-01

    Restriction endonuclease fragment length variations (RFLV) were detected in mice with DNA probes for myelin basic protein (Mbp), glucocorticoid receptor-1 (Grl-1), and Friend MuLV integration site-2 (Fim-2). RFLV of the Mbp gene were found in SacI restriction patterns, RFLV of the Grl-1 gene were found in EcoRV patterns, and RFLV of the Fim-2 were found in BglII patterns. A three-point backcross was carried out by the backcross mating (C57BL/KsJ-spm/spm x MOL-MIT)F1 males x C57BL/KsJ-spm/spm; spm is an autosomal recessive gene causing sphingomyelinosis. From the results, spm, Grl-1, Fim-2, and Mbp loci were mapped on chromosome 18, and the following order of genes is proposed, with distances between genes in parentheses: centromere--spm--(7.8 cM)--Grl-1--(7.8 cM)--Fim-2--(39.1 cM)--Mbp--telomere. All laboratory strains and two European subspecies (Mus mus domesticus and M. m. brevirostris) carry the Grl-1a, Fim-2a, and Mbpa alleles. In contrast, another wild subspecies from Europe (M. m. musculus) and some Asian subspecies (M. m. molossinus, Chinese mice of wild origin, and M. m. yamashinai) carry the Grl-1b, Fim-2b, and Mbpb alleles. Only castaneus strains carry the intermediate combination of the Grl-1b, Fim-2a, and Mbpb alleles.

  18. Construction of a Genetic Linkage Map in Mungbean%绿豆高密度分子遗传图谱的构建

    Institute of Scientific and Technical Information of China (English)

    吴传书; 王丽侠; 王素华; 陈红霖; 吴健新; 程须珍; 杨晓明

    2014-01-01

    amplification 97 pairs, the effective rate of 22.9%, obtained 6 pairs of polymorphic primers;Mungbean STS primers 13 pairs, effective amplification 9 pairs, the effective rate of 69.2%, obtained 2 pairs of polymorphic primers; These results indicated that different sources and types of SSR primers to amplify the effective rate of the parent were significantly different. Mungbean EST-SSR primers (84.6%) were the highest, mungbean STS primers (69.2%) and mungbean SSR primers (55.7%) followed, common bean SSR primers (22.9%) were the lowest. An integrated genetic linkage map of mungbean containing 585 markers was constructed (including 499 SSR markers, 74 RAPD markers, 9 STS markers and 3 RAPD markers). The total length of the map was 732.9 cM and covered 11 linkage groups. The average distance between markers was 1.25 cM. The average distance of each linkage group spanned 66.63 cM. The average number of markers was 53.18 for each of 11 chromosomes. The length of each linkage group ranged from 35 to 92 markers was from 45.2 cM to 112.8 cM. LG1 linkage group contained the largest number of 92 markers, the length was 112.8 cM. LG11 linkage group contained the minimum number of 35 markers, the length was 48.7 cM. Of the 585 markers loci mapping conductedχ2 tests under P<0.05 and P<0.01 conditions, respectively, 79 and 151 markers showed a segregation distortion, the total number of sites marked 39.3%.[Conclusion]A linkage map of mungbean with a maximum and the highest density genetic markers was constructed compared with that published at home and abroad at present.

  19. The Barley Chromosome 5 Linkage Map

    DEFF Research Database (Denmark)

    Jensen, J.; Jørgensen, Jørgen Helms

    1975-01-01

    The literature is surveyed for data on recombination between loci on chromosome 5 of barley; 13 loci fall into the category “mapped” loci, more than 20 into the category “associated” loci and nine into the category “loci once suggested to be on chromosome 5”. A procedure was developed...... for estimating a linkage map; it involves (1) transformation by the Kosambi mapping function of the available recombination percentages to additive map distances, (2) calculations of a set of map distances from the transformed recombination percentages by a maximum likelihood method in which all the available...... data are utilized jointly, and (3) omission of inconsistent data and determination of the most likely order of the loci. This procedure was applied to the 42 recombination percentages available for the 13 “mapped” loci. Due to inconsistencies 14 of the recombination percentages and, therefore, two...

  20. The CEPH consortium linkage map of human chromosome 13

    Energy Technology Data Exchange (ETDEWEB)

    Bowcock, A.M.; Barnes, R.I. [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States); Gerken, S.C.; Leppert, M. [Univ. of Utah School of Medicine, Salt Lake City, UT (United States); Shiang, R. [Univ. of Iowa, Iowa City, IA (United States); Jabs, E.W.; Warren, A.C.; Antonarakis, S. [Johns Hopkins School of Medicine, Baltimore, MD (United States); Retief, A.E. [Univ. of Stellenbosch, Tygerberg (South Africa); Vergnaud, G. [Centre d`Etudes du Bouchet, Vert le Petit (France)] [and others

    1993-05-01

    The CEPH consortium map of chromosome 13 is presented. This map contains 59 loci defined by genotypes generated from CEPH family DNAs with 94 different probe and restriction enzyme combinations contributed by 9 laboratories. A total of 25 loci have been placed on the map with likelihood support of at least 1000:1. The map extends from loci in the centromeric region of chromosome 13 to the terminal band of the long arm. Multipoint linkage analyses provided estimates that the male, female, and sex-averaged maps extend for 158, 203, and 178cM respectively. The largest interval is 24 cM and is between D13Z1 (alphaRI) and ATP1AL1. The mean genetic distance between the 25 uniquely placed loci is 7 cM. 76 refs., 3 figs., 5 tabs.

  1. Microsatellite loci for genetic mapping in the turkey (Meleagris gallopavo).

    Science.gov (United States)

    Reed, K M; Chaves, L D; Hall, M K; Knutson, T P; Rowe, J A; Torgerson, A J

    2003-11-01

    New microsatellite loci for the turkey (Meleagris gallopavo) were developed from two small insert DNA libraries. Polymorphism at these new loci was examined in domestic birds and two resource populations designed for genetic linkage mapping. The majority of loci (152 of 168) was polymorphic in domestic turkeys and informative in two mapping resource populations and thus will be useful for genetic linkage mapping.

  2. Development of cleaved amplified polymorphic sequence markers and a CAPS-based genetic linkage map in watermelon (Citrullus lanatus [Thunb.] Matsum. and Nakai) constructed using whole-genome re-sequencing data.

    Science.gov (United States)

    Liu, Shi; Gao, Peng; Zhu, Qianglong; Luan, Feishi; Davis, Angela R; Wang, Xiaolu

    2016-03-01

    Cleaved amplified polymorphic sequence (CAPS) markers are useful tools for detecting single nucleotide polymorphisms (SNPs). This study detected and converted SNP sites into CAPS markers based on high-throughput re-sequencing data in watermelon, for linkage map construction and quantitative trait locus (QTL) analysis. Two inbred lines, Cream of Saskatchewan (COS) and LSW-177 had been re-sequenced and analyzed by Perl self-compiled script for CAPS marker development. 88.7% and 78.5% of the assembled sequences of the two parental materials could map to the reference watermelon genome, respectively. Comparative assembled genome data analysis provided 225,693 and 19,268 SNPs and indels between the two materials. 532 pairs of CAPS markers were designed with 16 restriction enzymes, among which 271 pairs of primers gave distinct bands of the expected length and polymorphic bands, via PCR and enzyme digestion, with a polymorphic rate of 50.94%. Using the new CAPS markers, an initial CAPS-based genetic linkage map was constructed with the F2 population, spanning 1836.51 cM with 11 linkage groups and 301 markers. 12 QTLs were detected related to fruit flesh color, length, width, shape index, and brix content. These newly CAPS markers will be a valuable resource for breeding programs and genetic studies of watermelon.

  3. Generation of a Restriction Fragment Length Polymorphism Linkage Map for Toxoplasma Gondii

    Science.gov (United States)

    Sibley, L. D.; LeBlanc, A. J.; Pfefferkorn, E. R.; Boothroyd, J. C.

    1992-01-01

    We have constructed a genetic linkage map for the parasitic protozoan, Toxoplasma gondii, using randomly selected low copy number DNA markers that define restriction fragment length polymorphisms (RFLPs). The inheritance patterns of 64 RFLP markers and two phenotypic markers were analyzed among 19 recombinant haploid progeny selected from two parallel genetic crosses between PLK and CEP strains. In these first successful interstrain crosses, these RFLP markers segregated into 11 distinct genetic linkage groups that showed close correlation with physical linkage groups previously defined by molecular karyotype. Separate linkage maps, constructed for each of the 11 chromosomes, indicated recombination frequencies range from approximately 100 to 300 kb per centimorgan. Preliminary linkage assignments were made for the loci regulating sinefungin resistance (snf-1) on chromosome IX and adenine arabinoside (ara-1) on chromosome V by linkage to RFLP markers. Despite random segregation of separate chromosomes, the majority of chromosomes failed to demonstrate internal recombination events and in 3/19 recombinant progeny no intramolecular recombination events were detected. The relatively low rate of intrachromosomal recombination predicts that tight linkage for unknown genes can be established with a relatively small set of markers. This genetic linkage map should prove useful in mapping genes that regulate drug resistance and other biological phenotypes in this important opportunistic pathogen. PMID:1360931

  4. Molecular mapping and characterization of genes governing time to flowering, seed weight, and plant height in an intraspecific genetic linkage map of chickpea (Cicer arietinum).

    Science.gov (United States)

    Jamalabadi, Javad Ghorbani; Saidi, Abbas; Karami, Ezzat; Kharkesh, Mehrab; Talebi, Reza

    2013-06-01

    Drought is the major constraint to chickpea productivity worldwide. Utilizing early flowering genotypes and larger seed size have been suggested as strategies for breeding in drought zones. Therefore, this study aimed to identify potential markers linked to days-to-flowering, 100-seed weight, and plant height in a chickpea intraspecific F(2:3) population derived from the cross ILC3279 × ICCV2. A closely linked marker (TA117) on linkage group LG3 was identified for the days-to-flowering trait, explaining 33% of the variation. In relation to plant height, a quantitative trait loci (QTL) was located in LG3, close to the Ts5 marker, that explained 29% of phenotypic variation. A QTL for 100-seed weight located in LG4, close to TA176, explained 51% of variation. The identification of a locus linked both to high 100-seed weight and days-to-flowering may account for the correlation observed between these traits in this and other breeding attempts.

  5. A genetic linkage map of black raspberry (Rubus occidentalis) and the mapping of Ag4 conferring resistance to the aphid Amphorophora agathonica

    Science.gov (United States)

    Black raspberry (Rubus occidentalis L.) is a high-value crop in the Pacific Northwest of North America with an international marketplace. Few genetic resources are readily available and little improvement has been achieved through breeding efforts to address production challenges involved in growing...

  6. An integrated resource for barley linkage map and malting quality QTL alignment

    Science.gov (United States)

    Barley (Hordeum vulgare subsp. vulgare) is an economically important model plant for genetics research that is currently served by a comprehensive set of tools for genetic analysis. High density genetic linkage maps constructed from the inheritance of robust gene-based Single Nucleotide Polymorphism...

  7. The genetic differences with whole genome linkage disequilibrium mapping between responder and non-responder in interferon-alpha and ribavirin combined therapy for chronic hepatitis C patients.

    Science.gov (United States)

    Chen, P-J; Hwang, Y; Lin, C G-J; Wu, Y-J; Wu, L S-H

    2008-04-01

    Interferon-alpha and ribavirin combined therapy has been a mainstream treatment for hepatitis C infection. The efficacy of this combined treatment is around 30% to 60%, and the factors affecting the responsiveness are still poorly defined. Our study is intended to investigate the genetic differences between responder and non-responder patients. The genome-wide linkage disequilibrium screening for loci associated with genetic difference between two patient groups was conducted by using 382 autosomal short tandem repeat (STR) markers involving 92 patients. We have identified 19 STR markers displaying different allele frequencies between the two patient groups. In addition, based on their genomic location and biological function, we selected the CD81 and IL15 genes to perform single nucleotide polymorphism genotyping. In conclusion, this study may provide a new approach for identifying the associated polymorphisms and the susceptible loci for interferon-alpha and ribavirin combined therapy in patients with chronic hepatitis C.

  8. Development of a black gram [Vigna mungo (L.) Hepper] linkage map and its comparison with an azuki bean [Vigna angularis (Willd.) Ohwi and Ohashi] linkage map.

    Science.gov (United States)

    Chaitieng, B; Kaga, A; Tomooka, N; Isemura, T; Kuroda, Y; Vaughan, D A

    2006-11-01

    The Asian Vigna group of grain legumes consists of six domesticated species, among them black gram is widely grown in South Asia and to a lesser extent in Southeast Asia. We report the first genetic linkage map of black gram [Vigna mungo (L.) Hepper], constructed using a BC(1)F(1) population consisting of 180 individuals. The BC(1)F(1) population was analyzed in 61 SSR primer pairs, 56 RFLP probes, 27 AFLP loci and 1 morphological marker. About 148 marker loci could be assigned to the 11 linkage groups, which correspond to the haploid chromosome number of black gram. The linkage groups cover a total of 783 cM of the black gram genome. The number of markers per linkage group ranges from 6 to 23. The average distance between adjacent markers varied from 3.5 to 9.3 cM. The results of comparative genome mapping between black gram and azuki bean show that the linkage order of markers is highly conserved. However, inversions, insertions, deletions/duplications and a translocation were detected between the black gram and azuki bean linkage maps. The marker order on parts of linkage groups 1, 2 and 5 is reversed between the two species. One region on black gram linkage group 10 appears to correspond to part of azuki bean linkage group 1. The present study suggests that the azuki bean SSR markers can be widely used for Asian Vigna species and the black gram genetic linkage map will assist in improvement of this crop.

  9. Genetic Diversity, Population Structure, and Linkage Disequilibrium of an Association-Mapping Panel Revealed by Genome-Wide SNP Markers in Sesame

    Science.gov (United States)

    Cui, Chengqi; Mei, Hongxian; Liu, Yanyang; Zhang, Haiyang; Zheng, Yongzhan

    2017-01-01

    The characterization of genetic diversity and population structure can be used in tandem to detect reliable phenotype–genotype associations. In the present study, we genotyped a set of 366 sesame germplasm accessions by using 89,924 single-nucleotide polymorphisms (SNPs). The number of SNPs on each chromosome was consistent with the physical length of the respective chromosome, and the average marker density was approximately 2.67 kb/SNP. The genetic diversity analysis showed that the average nucleotide diversity of the panel was 1.1 × 10-3, with averages of 1.0 × 10-4, 2.7 × 10-4, and 3.6 × 10-4 obtained, respectively for three identified subgroups of the panel: Pop 1, Pop 2, and the Mixed. The genetic structure analysis revealed that these sesame germplasm accessions were structured primarily along the basis of their geographic collection, and that an extensive admixture occurred in the panel. The genome-wide linkage disequilibrium (LD) analysis showed that an average LD extended up to ∼99 kb. The genetic diversity and population structure revealed in this study should provide guidance to the future design of association studies and the systematic utilization of the genetic variation characterizing the sesame panel. PMID:28729877

  10. A first linkage map of pecan cultivars based on RAPD and AFLP markers.

    Science.gov (United States)

    Beedanagari, Sudheer R; Dove, Sue K; Wood, Bruce W; Conner, Patrick J

    2005-04-01

    We report here the first genetic linkage maps of pecan [Carya illinoinensis (Wangenh.) K. Koch], using random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers. Independent maps were constructed for the cultivars 'Pawnee' and 'Elliot' using the double pseudo-testcross mapping strategy and 120 F1 seedlings from a full-sib family. A total of 477 markers, including 217 RAPD, 258 AFLP, and two morphological markers were used in linkage analysis. The 'Pawnee' linkage map has 218 markers, comprising 176 testcross and 42 intercross markers placed in 16 major and 13 minor (doublets and triplets) linkage groups. The 'Pawnee' linkage map covered 2,227 cM with an average map distance of 12.7 cM between adjacent markers. The 'Elliot' linkage map has 174 markers comprising 150 testcross and 22 intercross markers placed in 17 major and nine minor linkage groups. The 'Elliot' map covered 1,698 cM with an average map distance of 11.2 cM between adjacent markers. Segregation ratios for dichogamy type and stigma color were not significantly different from 1:1, suggesting that both traits are controlled by single loci with protogyny and green stigmas dominant to protandry and red stigmas. These loci were tightly linked (1.9 cM) and were placed in 'Elliot' linkage group 16. These linkage maps are an important first step towards the detection of genes controlling horticulturally important traits such as nut size, nut maturity date, kernel quality, and disease resistance.

  11. Construction of a Genetic Linkage Map and Identification of QTLs for Seed Weight and Seed Size Traits in Lentil (Lens culinaris Medik..

    Directory of Open Access Journals (Sweden)

    Priyanka Verma

    Full Text Available Seed weight and seed size both are quantitative traits and have been considered as important components of grain yield, thus identification of quantitative trait loci (QTL for seed traits in lentil (Lens culinaris would be beneficial for the improvement of grain yield. Hence the main objective of this study was to identify QTLs for seed traits using an intraspecific mapping population derived from a cross between L. culinaris cv. Precoz (seed weight-5.1g, seed size-5.7mm and L. culinaris cv. L830 (seed weight-2.2g, seed size-4mm comprising 126 F8-RILs. For this, two microsatellite genomic libraries enriched for (GA/CT and (GAA/CTT motif were constructed which resulted in the development of 501 new genomic SSR markers. Six hundred forty seven SSR markers (including 146 previously published were screened for parental polymorphism and 219 (33.8% were found to be polymorphic among the parents. Of these 216 were mapped on seven linkage groups at LOD4.0 spanning 1183.7cM with an average marker density of 5.48cM. Phenotypic data from the RILs was used to identify QTLs for the seed weight and seed size traits by single marker analysis (SMA followed by composite interval mapping (CIM which resulted in one QTL each for the 2 traits (qSW and qSS that were co-localized on LG4 and explained 48.4% and 27.5% of phenotypic variance respectively. The current study would serve as a strong foundation for further validation and fine mapping for utilization in lentil breeding programs.

  12. Genetic Analysis and Linkage Mapping in a Resource Pig Population Using Microsatellite Markers%微卫星标记对资源猪群的遗传分析和连锁图谱构建

    Institute of Scientific and Technical Information of China (English)

    张敬虎; 熊远著; 左波; 雷明刚; 蒋思文; 李凤娥; 郑嵘; 李家连

    2007-01-01

    The use of markers and linkage map construction are important for QTL mapping in pigs.In this article, the genetic characteristics were studied and the linkage map was constructed in a pig resource population including 214 individuals by typing 39 microsatellite marker loci on Sus scrofa chromosomes, SSC4, SSC6, SSC7, SSC8, and SSC13.Results indicated that the average allele number, the average observed heterozygosity (Ho), and the average polymorphism information content (PIC) in F1 and F2population were 3.2, 0.528, 0.463 and 3.2, 0.496, 0.447, respectively.In the pig resource population, the average informative meiosis (IM) was 217.4 (44-316), and the average linkage map length between the two sexes on the five chromosomes were 172.3 cM (SSC4), 168.7 cM (SSC6), 191.7 cM (SSC7), 197.3 cM (SSC8), and 178.3 cM (SSC13).The orders of microsatellite marker loci in the linkage maps were identical to, but the length was greater than, those of USDA-MARC reference map.The results of this research showed the genetic relationship and genetic characteristics of the microsatellite markers in the pig resource family population,and the linkage map could be used to for QTL mapping in the subsequent study.%在猪数量性状位点的定位研究中,标记的使用和图谱的构建是很重要的.本研究从猪的第4、6、7、8和13染色体上选取39个微卫星标记,在来源于约克夏和梅山214头猪组成的资源群中,分析了遗传特征并构建了图谱.研究表明,平均等位基因数、平均观察杂合度(Ho)和平均多态信息含量(PIC)在F1和F2代中分别为:3.2,0.528,0.463和3.2,0.496,0.447.结果表明大多数微卫星标记位点表现为中高度杂合性.在资源群体中,平均有信息减数分裂数是217.4(44-316),而各染色体上两性平均图谱的长度分别是:172.3 cM(SSC4),168.7 cM(SSC6),191.7 cM(SSC7),197.3 cM(SSC8),178.3 cM(SSC13).与USDA-MARC的参考图谱相比,标记位点的顺序相同,但长度均较

  13. Construction of a SNP and SSR linkage map in autotetraploid blueberry using genotyping by sequencing

    Science.gov (United States)

    A mapping population developed from a cross between two key highbush blueberry cultivars, Draper × Jewel (Vaccinium corymbosum), segregating for a number of important phenotypic traits, has been utilized to produce a genetic linkage map. Data on 233 single sequence repeat (SSR) markers and 1794 sing...

  14. The construction of genetic linkage frame map in tetraploid Medicago using RAPD markers%利用RAPD技术构建四倍体苜蓿遗传连锁图谱

    Institute of Scientific and Technical Information of China (English)

    刘曙娜; 于林清; 周延林; 吉仁花; 陈世茹; 孙娟娟; 么婷婷

    2012-01-01

    Using random amplified polymorphic DNA (RAPD) molecular genetic markers analyze the F2 population of 94 plant individuals. The F2 segregating population derived from a self-pollinated F1 hybrid individual of the cross Medicago sativa ×Medicago falcata. The genetic analyses were performed by using maximum-likelihood equations and related computer programs. The genetic map comprises 74 markers, and contains 8 linkage groups covering 1 261. 5 cM, with an average distance of 24. 73 cM between markers. This genetic linkage map provides an entry point for the construction of saturated tetraploid alfalfa molecular genetic map and further development of alfalfa molecular genetic research.%利用随机扩增DNA多态性分子遗传标记(RAPD)对F2群体进行分析.F2群体由F1群体(高产紫花苜蓿×高抗黄花苜蓿得到F1代)自交获得.应用MAPMAKER/EXP(3.0)与JionMap 4.0并结合MapDrawV 2.1软件构建四倍体苜蓿的遗传连锁图谱.从192个随机引物中筛选出72个引物,对94个F2个体及F1双亲DNA样本进行了RAPD扩增,共获得51个RAPD标记,构建了四倍体苜蓿分子遗传连锁框架图,其中包含8个连锁群,标记覆盖的基因组总长度约为1 261.5 cM,标记间平均距离为24.73 cM.本图谱为构建饱和的四倍体苜蓿分子遗传图谱提供了框架结构,为进一步开展苜蓿分子遗传方面的研究奠定了基础.

  15. Fine mapping quantitative trait loci under selective phenotyping strategies based on linkage and linkage disequilibrium criteria

    DEFF Research Database (Denmark)

    Ansari-Mahyari, S; Berg, P; Lund, M S

    2009-01-01

    In fine mapping of a large-scale experimental population where collection of phenotypes are very expensive, difficult to record or time-demanding, selective phenotyping could be used to phenotype the most informative individuals. Linkage analyses based sampling criteria (LAC) and linkage...... disequilibrium-based sampling criteria (LDC) for selecting individuals to phenotype are compared to random phenotyping in a quantitative trait loci (QTL) verification experiment using stochastic simulation. Several strategies based on LAC and LDC for selecting the most informative 30%, 40% or 50% of individuals...... for phenotyping to extract maximum power and precision in a QTL fine mapping experiment were developed and assessed. Linkage analyses for the mapping was performed for individuals sampled on LAC within families and combined linkage disequilibrium and linkage analyses was performed for individuals sampled across...

  16. A RAD-based linkage map and comparative genomics in the gudgeons (genus Gnathopogon, Cyprinidae

    Directory of Open Access Journals (Sweden)

    Kakioka Ryo

    2013-01-01

    Full Text Available Abstract Background The construction of linkage maps is a first step in exploring the genetic basis for adaptive phenotypic divergence in closely related species by quantitative trait locus (QTL analysis. Linkage maps are also useful for comparative genomics in non-model organisms. Advances in genomics technologies make it more feasible than ever to study the genetics of adaptation in natural populations. Restriction-site associated DNA (RAD sequencing in next-generation sequencers facilitates the development of many genetic markers and genotyping. We aimed to construct a linkage map of the gudgeons of the genus Gnathopogon (Cyprinidae for comparative genomics with the zebrafish Danio rerio (a member of the same family as gudgeons and for the future QTL analysis of the genetic architecture underlying adaptive phenotypic evolution of Gnathopogon. Results We constructed the first genetic linkage map of Gnathopogon using a 198 F2 interspecific cross between two closely related species in Japan: river-dwelling Gnathopogon elongatus and lake-dwelling Gnathopogon caerulescens. Based on 1,622 RAD-tag markers, a linkage map spanning 1,390.9 cM with 25 linkage groups and an average marker interval of 0.87 cM was constructed. We also identified a region involving female-specific transmission ratio distortion (TRD. Synteny and collinearity were extensively conserved between Gnathopogon and zebrafish. Conclusions The dense SNP-based linkage map presented here provides a basis for future QTL analysis. It will also be useful for transferring genomic information from a “traditional” model fish species, zebrafish, to screen candidate genes underlying ecologically important traits of the gudgeons.

  17. A RAD-based linkage map and comparative genomics in the gudgeons (genus Gnathopogon, Cyprinidae)

    Science.gov (United States)

    2013-01-01

    Background The construction of linkage maps is a first step in exploring the genetic basis for adaptive phenotypic divergence in closely related species by quantitative trait locus (QTL) analysis. Linkage maps are also useful for comparative genomics in non-model organisms. Advances in genomics technologies make it more feasible than ever to study the genetics of adaptation in natural populations. Restriction-site associated DNA (RAD) sequencing in next-generation sequencers facilitates the development of many genetic markers and genotyping. We aimed to construct a linkage map of the gudgeons of the genus Gnathopogon (Cyprinidae) for comparative genomics with the zebrafish Danio rerio (a member of the same family as gudgeons) and for the future QTL analysis of the genetic architecture underlying adaptive phenotypic evolution of Gnathopogon. Results We constructed the first genetic linkage map of Gnathopogon using a 198 F2 interspecific cross between two closely related species in Japan: river-dwelling Gnathopogon elongatus and lake-dwelling Gnathopogon caerulescens. Based on 1,622 RAD-tag markers, a linkage map spanning 1,390.9 cM with 25 linkage groups and an average marker interval of 0.87 cM was constructed. We also identified a region involving female-specific transmission ratio distortion (TRD). Synteny and collinearity were extensively conserved between Gnathopogon and zebrafish. Conclusions The dense SNP-based linkage map presented here provides a basis for future QTL analysis. It will also be useful for transferring genomic information from a “traditional” model fish species, zebrafish, to screen candidate genes underlying ecologically important traits of the gudgeons. PMID:23324215

  18. Recombination patterns reveal information about centromere location on linkage maps

    DEFF Research Database (Denmark)

    Limborg, Morten T.; McKinney, Garrett J.; Seeb, Lisa W.

    2016-01-01

    , approximate centromere placement is possible by phasing the same data used to generate linkage maps. Assuming one obligate crossover per chromosome arm, information about centromere location can be revealed by tracking the accumulated recombination frequency along linkage groups, similar to half....... mykiss) characterized by low and unevenly distributed recombination – a general feature of male meiosis in many species. Further, a high frequency of double crossovers along chromosome arms in barley reduced resolution for locating centromeric regions on most linkage groups. Despite these limitations......, our method should work well for high‐density maps in species with strong recombination interference and will enrich many existing and future mapping resources....

  19. A male linkage map constructed for QTL mapping in Spanish Churra sheep.

    Science.gov (United States)

    Gutiérrez-Gil, B; Arranz, J J; El-Zarei, M F; Alvarez, L; Pedrosa, S; San Primitivo, F; Bayón, Y

    2008-06-01

    A male ovine linkage map has been constructed on the basis of 11 half-sib families of a commercial population of Spanish Churra sheep as part of a genome scan for quantitative trait loci mapping. A total of 1421 daughters and their sires were genotyped for 182 microsatellite markers evenly distributed along the ovine autosomes. A total of 259,192 genotypes were obtained, generating an average of 669 informative meioses per marker. An autosomal genome length of 3262 cM was estimated for the Churra population with a mean marker interval of 17.86 cM. Our map represents an approximate 90% coverage of the autosomal ovine genome and constitutes a useful tool for the genetic dissection of complex traits in this breed. General agreement was found between the Churra map and other published maps for sheep, despite certain length discrepancies.

  20. A Genetic Linkage Map for Naked Oat (Avena nuda L.)%大粒裸燕麦(Avena nuda L.)遗传连锁图谱的构建

    Institute of Scientific and Technical Information of China (English)

    徐微; 张宗文; 张恩来; 吴斌

    2013-01-01

    Based on 281 individual plants of F2 population derived from a cross "Yuan Naked Oat"x"555",a genetic linkage map for naked oat (Avena nuda L.) was constructed by 20 AFLP primer pairs,3 SSR primer pairs,and 1 panicle type character.The map was 1544.8 cM in total length with 20.1 cM for the average distance between neighboring markers.92 AFLP markers,3 SSR markers,and 1 morphological trait were mapped on 19 linkage groups,which contained 2-14 markers and varied in size from 23.7 cM to 276.3 cM with an average of 81.3 cM.The segregation ratio of panicle type fitted to 3:1,and 11 AFLP markers demonstrated distorted segregation with the percentage of 11.5%.The results provided a framework of genetic linkage map for naked oat (Avena nuda L.),which was the theoretical basis for QTL mapping,molecular breeding,and comparative genomics in naked oat research.%以元莜麦和555杂交得到的281个F2单株为作图群体,利用20对AFLP引物、3对SSR引物和1个穗型性状构建了一张大粒裸燕麦遗传连锁图.该图谱全长1544.8 cM,包含19个连锁群,其上分布有92个AFLP标记、3个SSR标记和1个穗型形态标记,不同连锁群标记数为2 ~14个,长度在23.7 ~276.3 cM之间,平均长度为81.3 cM,标记间平均距离为20.1 cM.穗型标记分离比符合3:1,11个AFLP标记表现为偏分离,偏分离比为11.5%.该图谱符合遗传连锁框架图的要求,为今后大粒裸燕麦的QTL定位、分子标记辅助育种和比较基因组学等研究奠定基础.

  1. A first generation microsatellite- and SNP-based linkage map of Jatropha.

    Directory of Open Access Journals (Sweden)

    Chun Ming Wang

    Full Text Available Jatropha curcas is a potential plant species for biodiesel production. However, its seed yield is too low for profitable production of biodiesel. To improve the productivity, genetic improvement through breeding is essential. A linkage map is an important component in molecular breeding. We established a first-generation linkage map using a mapping panel containing two backcross populations with 93 progeny. We mapped 506 markers (216 microsatellites and 290 SNPs from ESTs onto 11 linkage groups. The total length of the map was 1440.9 cM with an average marker space of 2.8 cM. Blasting of 222 Jatropha ESTs containing polymorphic SSR or SNP markers against EST-databases revealed that 91.0%, 86.5% and 79.2% of Jatropha ESTs were homologous to counterparts in castor bean, poplar and Arabidopsis respectively. Mapping 192 orthologous markers to the assembled whole genome sequence of Arabidopsis thaliana identified 38 syntenic blocks and revealed that small linkage blocks were well conserved, but often shuffled. The first generation linkage map and the data of comparative mapping could lay a solid foundation for QTL mapping of agronomic traits, marker-assisted breeding and cloning genes responsible for phenotypic variation.

  2. Principles, requirements and prospects of genetic mapping in plants

    African Journals Online (AJOL)

    AJB SERVER

    Genetic mapping (also known as linkage mapping or meiotic mapping) refers to the determination of the relative ..... F2 is more powerful for detecting QTLs of additive effect, and can also be .... In general, cross pollinating ..... chromosome deletion stocks (Fox et al., 2001). ..... The cytological basis of genetical interference.

  3. Formal genetic maps

    African Journals Online (AJOL)

    Mohammad Saad Zaghloul Salem

    2014-12-24

    Dec 24, 2014 ... Abstract Formal genetic maps are databases, represented as text or graphic figures, that can be ..... cantly, to our current vague and scanty knowledge of many, ...... similar to reverse engineering techniques, might be worthy of.

  4. A population genetics model of linkage disequilibrium in admixed populations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Understanding linkage disequilibrium (LD) created in admixed population and the rate of decay in the disequilibrium over evolution is an important subject in population genetics theory and in disease gene mapping in human populations. The present study represents the theoretical investigation of effects of gene frequencies, levels of LD and admixture proportions of donor populations on the evolutionary dynamics of the LD of the admixed population. We examined the conditions under which the admixed population reached linkage equilibrium or the peak level of the LD. The study reveals the inappropriateness in approximating the dynamics of the LD generated by population admixture by the commonly used formula in literature. An appropriate equation for the dynamics is proposed. The distinct feature of the newly suggested formula is that the value of the nonlinear component of the LD remains constant in the first generation of the population evolution. Comparison between the predicted disequilibrium dynamics shows that the error will be caused by using the old formula, and thus resulting in a misguidance in using the evolutionary information of the admixed population in gene mapping.

  5. A consensus linkage map of the chicken genome

    NARCIS (Netherlands)

    Groenen, M.A.M.; Cheng, H.H.; Bumstead, N.; Benkel, B.; Briles, E.; Burt, D.W.; Burke, T.; Dodgson, J.; Hillel, J.; Lamont, S.; Ponce, de F.A.; Soller, M.

    2000-01-01

    A consensus linkage map has been developed in the chicken that combines all of the genotyping data from the three available chicken mapping populations. Genotyping data were contributed by the laboratories that have been using the East Lansing and Compton reference populations and from the Animal Br

  6. A consensus linkage map of the chicken genome

    NARCIS (Netherlands)

    Groenen, M.A.M.; Cheng, H.H.; Bumstead, N.; Benkel, B.; Briles, E.; Burt, D.W.; Burke, T.; Dodgson, J.; Hillel, J.; Lamont, S.; Ponce, de F.A.; Soller, M.

    2000-01-01

    A consensus linkage map has been developed in the chicken that combines all of the genotyping data from the three available chicken mapping populations. Genotyping data were contributed by the laboratories that have been using the East Lansing and Compton reference populations and from the Animal

  7. Linkage disequilibrium fine mapping of quantitative trait loci: A simulation study

    Directory of Open Access Journals (Sweden)

    Pérez-Enciso Miguel

    2003-09-01

    Full Text Available Abstract Recently, the use of linkage disequilibrium (LD to locate genes which affect quantitative traits (QTL has received an increasing interest, but the plausibility of fine mapping using linkage disequilibrium techniques for QTL has not been well studied. The main objectives of this work were to (1 measure the extent and pattern of LD between a putative QTL and nearby markers in finite populations and (2 investigate the usefulness of LD in fine mapping QTL in simulated populations using a dense map of multiallelic or biallelic marker loci. The test of association between a marker and QTL and the power of the test were calculated based on single-marker regression analysis. The results show the presence of substantial linkage disequilibrium with closely linked marker loci after 100 to 200 generations of random mating. Although the power to test the association with a frequent QTL of large effect was satisfactory, the power was low for the QTL with a small effect and/or low frequency. More powerful, multi-locus methods may be required to map low frequent QTL with small genetic effects, as well as combining both linkage and linkage disequilibrium information. The results also showed that multiallelic markers are more useful than biallelic markers to detect linkage disequilibrium and association at an equal distance.

  8. An Integrated Resource for Barley Linkage Map and Malting Quality QTL Alignment

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    Péter Szűcs

    2009-07-01

    Full Text Available Barley ( L. is an economically important model plant for genetics research. Barley is currently served by an increasingly comprehensive set of tools for genetic analysis that have recently been augmented by high-density genetic linkage maps built with gene-based single nucleotide polymorphisms (SNPs. These SNP-based maps need to be aligned with earlier generation maps, which were used for quantitative trait locus (QTL detection, by integrating multiple types of markers into a single map. A 2383 locus linkage map was developed using the Oregon Wolfe Barley (OWB Mapping Population to allow such alignments. The map is based on 1472 SNP, 722 DArT, and 189 prior markers which include morphological, simple sequence repeat (SSR, Restriction Fragment Length Polymorphism (RFLP, and sequence tagged site (STS loci. This new OWB map forms, therefore, a useful bridge between high-density SNP-only maps and prior QTL reports. The application of this bridge concept is shown using malting-quality QTLs from multiple mapping populations, as reported in the literature. This is the first step toward developing a Barley QTL Community Curation workbook for all types of QTLs and maps, on the GrainGenes website. The OWB-related resources are available at OWB Data and GrainGenes Tools (OWB-DGGT (.

  9. A molecular marker-based linkage map of diploid bananas (Musa acuminata).

    Science.gov (United States)

    Fauré, S; Noyer, J L; Horry, J P; Bakry, F; Lanaud, C; Gońzalez de León, D

    1993-12-01

    A partial molecular linkage map of the Musa acuminata diploid genome is presented. This map is based on 58 RFLP, four isozyme and 28 RAPD markers segregating in an F2 population of 92 individuals. A total of 90 loci was detected, 77 of which were placed on 15 linkage groups while 13 segregated independently. Segregation distortions were shown by 36% of all loci, mostly favoring the male parent. Chromosome structural rearrangements were believed to be one of the main causes of these distortions. The use of genetic linkage data to further the genetic and evolutionary knowledge of the genus Musa, as well as to help improve the design of breeding strategies, is discussed.

  10. A saturated SSR/DArT linkage map of Musa acuminata addressing genome rearrangements among bananas

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    Matsumoto Takashi

    2010-04-01

    Full Text Available Abstract Background The genus Musa is a large species complex which includes cultivars at diploid and triploid levels. These sterile and vegetatively propagated cultivars are based on the A genome from Musa acuminata, exclusively for sweet bananas such as Cavendish, or associated with the B genome (Musa balbisiana in cooking bananas such as Plantain varieties. In M. acuminata cultivars, structural heterozygosity is thought to be one of the main causes of sterility, which is essential for obtaining seedless fruits but hampers breeding. Only partial genetic maps are presently available due to chromosomal rearrangements within the parents of the mapping populations. This causes large segregation distortions inducing pseudo-linkages and difficulties in ordering markers in the linkage groups. The present study aims at producing a saturated linkage map of M. acuminata, taking into account hypotheses on the structural heterozygosity of the parents. Results An F1 progeny of 180 individuals was obtained from a cross between two genetically distant accessions of M. acuminata, 'Borneo' and 'Pisang Lilin' (P. Lilin. Based on the gametic recombination of each parent, two parental maps composed of SSR and DArT markers were established. A significant proportion of the markers (21.7% deviated (p Conclusions We propose a synthetic map with 11 linkage groups containing 489 markers (167 SSRs and 322 DArTs covering 1197 cM. This first saturated map is proposed as a "reference Musa map" for further analyses. We also propose two complete parental maps with interpretations of structural rearrangements localized on the linkage groups. The structural heterozygosity in P. Lilin is hypothesized to result from a duplication likely accompanied by an inversion on another chromosome. This paper also illustrates a methodological approach, transferable to other species, to investigate the mapping of structural rearrangements and determine their consequences on marker

  11. Integration of linkage maps for the Amphidiploid Brassica napus and comparative mapping with Arabidopsis and Brassica rapa

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    Delourme Régine

    2011-02-01

    Full Text Available Abstract Background The large number of genetic linkage maps representing Brassica chromosomes constitute a potential platform for studying crop traits and genome evolution within Brassicaceae. However, the alignment of existing maps remains a major challenge. The integration of these genetic maps will enhance genetic resolution, and provide a means to navigate between sequence-tagged loci, and with contiguous genome sequences as these become available. Results We report the first genome-wide integration of Brassica maps based on an automated pipeline which involved collation of genome-wide genotype data for sequence-tagged markers scored on three extensively used amphidiploid Brassica napus (2n = 38 populations. Representative markers were selected from consolidated maps for each population, and skeleton bin maps were generated. The skeleton maps for the three populations were then combined to generate an integrated map for each LG, comparing two different approaches, one encapsulated in JoinMap and the other in MergeMap. The BnaWAIT_01_2010a integrated genetic map was generated using JoinMap, and includes 5,162 genetic markers mapped onto 2,196 loci, with a total genetic length of 1,792 cM. The map density of one locus every 0.82 cM, corresponding to 515 Kbp, increases by at least three-fold the locus and marker density within the original maps. Within the B. napus integrated map we identified 103 conserved collinearity blocks relative to Arabidopsis, including five previously unreported blocks. The BnaWAIT_01_2010a map was used to investigate the integrity and conservation of order proposed for genome sequence scaffolds generated from the constituent A genome of Brassica rapa. Conclusions Our results provide a comprehensive genetic integration of the B. napus genome from a range of sources, which we anticipate will provide valuable information for rapeseed and Canola research.

  12. Construction of a genetic linkage map for tetraploid hybrid wheatgrass using a SSR molecular marker%利用 SSR 分子标记构建四倍体杂交冰草的遗传连锁图谱

    Institute of Scientific and Technical Information of China (English)

    姜志艳; 于肖夏; 于卓; 张志成; 石悦; 姜超

    2016-01-01

    为构建四倍体杂交冰草分子遗传连锁图谱,对深入开展冰草产量、抗性等重要性状的 QTL 定位及分子标记辅助育种提供依据,以四倍体杂种 F2分离群体的347个单株及亲本蒙古冰草和航道冰草为材料,采用 SSR 分子标记技术和 Joinmap 4.0软件进行了遗传作图研究。试验从256对 SSR 引物中筛选出条带清晰稳定、多态性丰富的适宜引物30对,PCR 扩增得到224个 SSR 标记位点,平均每对引物扩增出7.47个位点,其中多态性标记位点185个,占82.6%。偏分离分析显示,在185个 SSR 多态性标记位点中有24个标记产生偏分离,占13.0%,符合植物遗传作图时通常偏分离标记比率<30%的要求,可用于遗传作图。构建了1张四倍体杂交冰草的分子遗传连锁框架图谱,该图谱包含14个连锁群、185个标记,其长度范围在123.0~202.6 cM 之间,连锁群 LG4最长、LG12最短,各连锁群的平均长度167.32 cM,覆盖基因组总长度2342.5 cM,标记间的平均距离12.66 cM。%To establish a genetic linkage map in tetraploid hybrid wheatgrass genetic mapping was conducted u-sing a simple sequence repeats (SSR)molecular marker technique with ‘Joinmap’4.0 software.347 individu-als from the F2 segregating population and their parents were utilized,this helped lay the foundation for further study of marker-assisted breeding,and quantitative trait locus (QTL)location of important traits in wheat-grass,such as disease resistance and yield.Thirty optimal primers with clear,stable and high polymorphic bands were screened from 256 tested SSR primers.A total of 224 SSR loci were obtained from polymerase chain reaction (PCR)amplification with an average of 7.47 loci per primer,of which 185 were polymorphic lo-ci,accounting for 82.6% of all loci.Segregation distortion analysis showed that a total of 24 loci were distort-ed,accounted for 13.0% of all (185)polymorphic

  13. A SNP based high-density linkage map of Apis cerana reveals a high recombination rate similar to Apis mellifera.

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    Yuan Yuan Shi

    Full Text Available BACKGROUND: The Eastern honey bee, Apis cerana Fabricius, is distributed in southern and eastern Asia, from India and China to Korea and Japan and southeast to the Moluccas. This species is also widely kept for honey production besides Apis mellifera. Apis cerana is also a model organism for studying social behavior, caste determination, mating biology, sexual selection, and host-parasite interactions. Few resources are available for molecular research in this species, and a linkage map was never constructed. A linkage map is a prerequisite for quantitative trait loci mapping and for analyzing genome structure. We used the Chinese honey bee, Apis cerana cerana to construct the first linkage map in the Eastern honey bee. RESULTS: F2 workers (N = 103 were genotyped for 126,990 single nucleotide polymorphisms (SNPs. After filtering low quality and those not passing the Mendel test, we obtained 3,000 SNPs, 1,535 of these were informative and used to construct a linkage map. The preliminary map contains 19 linkage groups, we then mapped the 19 linkage groups to 16 chromosomes by comparing the markers to the genome of A. mellfiera. The final map contains 16 linkage groups with a total of 1,535 markers. The total genetic distance is 3,942.7 centimorgans (cM with the largest linkage group (180 loci measuring 574.5 cM. Average marker interval for all markers across the 16 linkage groups is 2.6 cM. CONCLUSION: We constructed a high density linkage map for A. c. cerana with 1,535 markers. Because the map is based on SNP markers, it will enable easier and faster genotyping assays than randomly amplified polymorphic DNA or microsatellite based maps used in A. mellifera.

  14. A gene-based SNP resource and linkage map for the copepod Tigriopus californicus

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    Foley Brad R

    2011-11-01

    Full Text Available Abstract Background As yet, few genomic resources have been developed in crustaceans. This lack is particularly evident in Copepoda, given the extraordinary numerical abundance, and taxonomic and ecological diversity of this group. Tigriopus californicus is ideally suited to serve as a genetic model copepod and has been the subject of extensive work in environmental stress and reproductive isolation. Accordingly, we set out to develop a broadly-useful panel of genetic markers and to construct a linkage map dense enough for quantitative trait locus detection in an interval mapping framework for T. californicus--a first for copepods. Results One hundred and ninety Single Nucleotide Polymorphisms (SNPs were used to genotype our mapping population of 250 F2 larvae. We were able to construct a linkage map with an average intermarker distance of 1.8 cM, and a maximum intermarker distance of 10.3 cM. All markers were assembled into linkage groups, and the 12 linkage groups corresponded to the 12 known chromosomes of T. californicus. We estimate a total genome size of 401.0 cM, and a total coverage of 73.7%. Seventy five percent of the mapped markers were detected in 9 additional populations of T. californicus. Of available model arthropod genomes, we were able to show more colocalized pairs of homologues between T. californicus and the honeybee Apis mellifera, than expected by chance, suggesting preserved macrosynteny between Hymenoptera and Copepoda. Conclusions Our study provides an abundance of linked markers spanning all chromosomes. Many of these markers are also found in multiple populations of T. californicus, and in two other species in the genus. The genomic resource we have developed will enable mapping throughout the geographical range of this species and in closely related species. This linkage map will facilitate genome sequencing, mapping and assembly in an ecologically and taxonomically interesting group for which genomic resources are

  15. A ddRAD Based Linkage Map of the Cultivated Strawberry, Fragaria xananassa.

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    Jahn Davik

    Full Text Available The cultivated strawberry (Fragaria ×ananassa Duch. is an allo-octoploid considered difficult to disentangle genetically due to its four relatively similar sub-genomic chromosome sets. This has been alleviated by the recent release of the strawberry IStraw90 whole genome genotyping array. However, array resolution relies on the genotypes used in the array construction and may be of limited general use. SNP detection based on reduced genomic sequencing approaches has the potential of providing better coverage in cases where the studied genotypes are only distantly related from the SNP array's construction foundation. Here we have used double digest restriction-associated DNA sequencing (ddRAD to identify SNPs in a 145 seedling F1 hybrid population raised from the cross between the cultivars Sonata (♀ and Babette (♂. A linkage map containing 907 markers which spanned 1,581.5 cM across 31 linkage groups representing the 28 chromosomes of the species. Comparing the physical span of the SNP markers with the F. vesca genome sequence, the linkage groups resolved covered 79% of the estimated 830 Mb of the F. × ananassa genome. Here, we have developed the first linkage map for F. × ananassa using ddRAD and show that this technique and other related techniques are useful tools for linkage map development and downstream genetic studies in the octoploid strawberry.

  16. A ddRAD Based Linkage Map of the Cultivated Strawberry, Fragaria xananassa.

    Science.gov (United States)

    Davik, Jahn; Sargent, Daniel James; Brurberg, May Bente; Lien, Sigbjørn; Kent, Matthew; Alsheikh, Muath

    2015-01-01

    The cultivated strawberry (Fragaria ×ananassa Duch.) is an allo-octoploid considered difficult to disentangle genetically due to its four relatively similar sub-genomic chromosome sets. This has been alleviated by the recent release of the strawberry IStraw90 whole genome genotyping array. However, array resolution relies on the genotypes used in the array construction and may be of limited general use. SNP detection based on reduced genomic sequencing approaches has the potential of providing better coverage in cases where the studied genotypes are only distantly related from the SNP array's construction foundation. Here we have used double digest restriction-associated DNA sequencing (ddRAD) to identify SNPs in a 145 seedling F1 hybrid population raised from the cross between the cultivars Sonata (♀) and Babette (♂). A linkage map containing 907 markers which spanned 1,581.5 cM across 31 linkage groups representing the 28 chromosomes of the species. Comparing the physical span of the SNP markers with the F. vesca genome sequence, the linkage groups resolved covered 79% of the estimated 830 Mb of the F. × ananassa genome. Here, we have developed the first linkage map for F. × ananassa using ddRAD and show that this technique and other related techniques are useful tools for linkage map development and downstream genetic studies in the octoploid strawberry.

  17. 利用重组自交系群体构建番茄AFLP遗传连锁图谱%Construction AFLP Genetic Linkage Map of Tomato Using Recombinant Inbred Lines (RILs) Population

    Institute of Scientific and Technical Information of China (English)

    陈丽静; 王利; 王玉坤; 陶承光; 李君明; 王晓武; 李天来

    2012-01-01

    以普通栽培番茄(Solanum lycopersicum)99165.30为母本,野生多毛番茄(Solanumhabrochaites)LAl777为父本进行杂交,通过单粒传得到了含有80个F5:6家系的重组自交系分离群体,利用荧光AFLP分子标记技术构建番茄分子遗传连锁图谱。AFLP标记采用MseI和EcoRI两种内切酶及荧光标记(IRD.700或IRD.800)的E+3和非荧光标记的M+3引物组合进行选择性扩增,扩增结果经95℃预变性后在6%变性聚丙烯酰胺凝胶上电泳2.5h,运用LICOR公司的NENGlobal Edition IR2 DNA Analyzer(Model 5200 LI-COR Biosciences,Lincoln,NE)荧光扫描检测DNA多态性。对RILs群体中产生分离的274个AFLP标记运用Join Map3.0软件分析,得到一张番茄分子遗传连锁图谱,图谱总长度为662cM,共包括18个主要连锁群,125个多态性分子标记。每条连锁群上的标记数在3~22个之间,连锁群的长度在14.0~58.0cM的范围内,平均图距在2-27~13-3cM。总平均距离5.3cM,本研究中构建的番茄永久遗传图谱,为番茄分子辅助育种及重要农艺性状的定位奠定了基础。%A genetic linkage map of tomato was constructed using a RILs (recombinant inbred lines) population of 80 individuals which was developed by crossing Solanum lycopersicum 99165-30 and Solanum habrochaites LA1777 through single-seed descent (SSD) . AFLPs were generated by the use of restriction enzymes EcoR I in combination with either Mse I. Pre-amplification was carded out using primers corresponding to EcoR I and Mse I adaptors with no selective base. Selective amplifications were performed using IRD700 or IRD800 labeled EcoR I primers and non-labeled Mse I primers. The resulting products were denatured in formamide at 95℃ and separated by electrophoresis 2.5 h on 6% polyacrylamide gel using IR2 DNA Analyzer (Model 5200 LI-COR Biosciences, Lincoln, NE) . The segregation of each marker and linkage analysis was done

  18. A SNP based linkage map of the turkey genome reveals multiple intrachromosomal rearrangements between the Turkey and Chicken genomes

    Directory of Open Access Journals (Sweden)

    Vereijken Addie

    2010-11-01

    Full Text Available Abstract Background The turkey (Meleagris gallopavo is an important agricultural species that is the second largest contributor to the world's poultry meat production. The genomic resources of turkey provide turkey breeders with tools needed for the genetic improvement of commercial breeds of turkey for economically important traits. A linkage map of turkey is essential not only for the mapping of quantitative trait loci, but also as a framework to enable the assignment of sequence contigs to specific chromosomes. Comparative genomics with chicken provides insight into mechanisms of genome evolution and helps in identifying rare genomic events such as genomic rearrangements and duplications/deletions. Results Eighteen full sib families, comprising 1008 (35 F1 and 973 F2 birds, were genotyped for 775 single nucleotide polymorphisms (SNPs. Of the 775 SNPs, 570 were informative and used to construct a linkage map in turkey. The final map contains 531 markers in 28 linkage groups. The total genetic distance covered by these linkage groups is 2,324 centimorgans (cM with the largest linkage group (81 loci measuring 326 cM. Average marker interval for all markers across the 28 linkage groups is 4.6 cM. Comparative mapping of turkey and chicken revealed two inter-, and 57 intrachromosomal rearrangements between these two species. Conclusion Our turkey genetic map of 531 markers reveals a genome length of 2,324 cM. Our linkage map provides an improvement of previously published maps because of the more even distribution of the markers and because the map is completely based on SNP markers enabling easier and faster genotyping assays than the microsatellitemarkers used in previous linkage maps. Turkey and chicken are shown to have a highly conserved genomic structure with a relatively low number of inter-, and intrachromosomal rearrangements.

  19. Linkage maps of the Atlantic salmon (Salmo salar) genome derived from RAD sequencing.

    Science.gov (United States)

    Gonen, Serap; Lowe, Natalie R; Cezard, Timothé; Gharbi, Karim; Bishop, Stephen C; Houston, Ross D

    2014-02-27

    Genetic linkage maps are useful tools for mapping quantitative trait loci (QTL) influencing variation in traits of interest in a population. Genotyping-by-sequencing approaches such as Restriction-site Associated DNA sequencing (RAD-Seq) now enable the rapid discovery and genotyping of genome-wide SNP markers suitable for the development of dense SNP linkage maps, including in non-model organisms such as Atlantic salmon (Salmo salar). This paper describes the development and characterisation of a high density SNP linkage map based on SbfI RAD-Seq SNP markers from two Atlantic salmon reference families. Approximately 6,000 SNPs were assigned to 29 linkage groups, utilising markers from known genomic locations as anchors. Linkage maps were then constructed for the four mapping parents separately. Overall map lengths were comparable between male and female parents, but the distribution of the SNPs showed sex-specific patterns with a greater degree of clustering of sire-segregating SNPs to single chromosome regions. The maps were integrated with the Atlantic salmon draft reference genome contigs, allowing the unique assignment of ~4,000 contigs to a linkage group. 112 genome contigs mapped to two or more linkage groups, highlighting regions of putative homeology within the salmon genome. A comparative genomics analysis with the stickleback reference genome identified putative genes closely linked to approximately half of the ordered SNPs and demonstrated blocks of orthology between the Atlantic salmon and stickleback genomes. A subset of 47 RAD-Seq SNPs were successfully validated using a high-throughput genotyping assay, with a correspondence of 97% between the two assays. This Atlantic salmon RAD-Seq linkage map is a resource for salmonid genomics research as genotyping-by-sequencing becomes increasingly common. This is aided by the integration of the SbfI RAD-Seq SNPs with existing reference maps and the draft reference genome, as well as the identification of

  20. Cytogenetical anchoring of sheep linkage map and syntenic groups using a sheep BAC library

    Directory of Open Access Journals (Sweden)

    Cribiu Edmond-Paul

    2000-07-01

    Full Text Available Abstract In order to simultaneously integrate linkage and syntenic groups to the ovine chromosomal map, a sheep bacterial artificial chromosome (BAC library was screened with previously assigned microsatellites using a sheep-hamster hybrid panel and genetic linkage. Thirty-three BACs were obtained, fluorescently labelled and hybridised on sheep-goat hybrid metaphases (2n = 57. This study allowed us, (i, to anchor all linkage groups on sheep chromosomes, (ii, to give information on the probable position of the centromere on the linkage map for the centromeric chromosomes, (iii, to contradict the previous orientation of the ovine × linkage group by the mapping of BMS1008 on OARXq38. Concerning our somatic cell hybrid panel, this study resulted in the assignment of all the previously unassigned groups to ovine chromosomes and a complete characterisation of the hybrid panel. In addition, since hybridisations were performed on a sheep-goat hybrid, new marker/anchoring points were added to the caprine cytogenetic map.

  1. 西瓜遗传图谱构建及果实相关性状QTL分析%Construction of a Genetic Linkage Map and QTL Analysis of Fruit-Associated Traits in Watermelon

    Institute of Scientific and Technical Information of China (English)

    刘传奇; 高鹏; 栾非时

    2014-01-01

    electrophoresis was used to detect the digestion products. SSR markers in this experiment were come from the published literature. The products of SSR-PCR were detected by polyacrylamid gel electrophoresis. All the molecular data were tested by chi-square. Markers which were confirmed the proportion 1﹕2﹕1 were chosen for the genetic linkage map. The genetic linkage map was constructed by Mapmaker/Exp version 3.0. The markers were grouped with the order ‘Group’. The number of the markers in the group which was less than 8 was sequenced faultlessly with the order ‘Compare’, which was more than 8 was ordered with the order ‘Try’. Map Chart 2.1 was used for drawing this genetic linkage map. QTL Network 2.0 was used for QTL analysis. 1 000 times repeats were done with the replacement testing, the critical threshold was P=0.005, and the method of constructing the map was composite interval mapping. The whole genome was scanned on every chromosome with 1 cM walking speed. QTL additive effect and epistatic effect were analyzed by the software.[Result]This genetic linkage map contained 16 linkage groups and included 87 CAPS markers and SSR markers. The map was 1 484.3 cM and the average distance between two makers was 15.46 cM. Mapping the QTL of the fruit-associated traits and analyzed by software QTL Network 2.0, and a total of 8 additive QTL and one pair of epistatic QTL were detected. Among the additive loci, 1 is for fruit shape index(QFSI 1), 1 for center brix (QCBR), 1 for center flesh firmness(QCFF), 1 for edge flesh firmness(QEFF), 1 for seed length(QSL), and 3 for seed width(QSWD 1,QSWD 2,QSWD 3). The epistatic loci,FSI 2 andFSI 3arefor fruit shape index. Phenotypic contribution rate of 10% or more have six QTL, which explained 11.7% -18.8% of the genetic variation. All of the QTL explained 7.12%-18.8% of the phenotypic variation.[Conclusion]A molecular genetic linkage map composed mainly of CAPS markers was constructed. Eight additive QTL and one pair of

  2. Genetic Algoritm Eclipse Mapping

    Science.gov (United States)

    Halevin, A. V.

    In this paper we analyse capabilities of eclipse mapping technique, based on genetic algorithm optimization. To model of accretion disk we used the "fire-flies" conception. This model allows us to reconstruct the distribution of radiating medium in the disk using less number of free parameters than in other methods. Test models show that we can achieve good approximation without optimizing techniques.

  3. Integrating haplotype-specific linkage maps in tetraploid species using SNP markers

    NARCIS (Netherlands)

    Bourke, Peter M.; Voorrips, Roeland E.; Kranenburg, Twan; Jansen, Hans; Visser, Richard G.F.; Maliepaard, Chris

    2016-01-01

    Key message: Linkage mapping can help unravel the complexities of polyploid genomes. Here, we integrate haplotype-specific linkage maps in autotetraploid potato and explore the possibilities for mapping in other polyploid species.Abstract: High-density linkage mapping in autopolyploid species has

  4. Construction of Commercial Sweet Cherry Linkage Maps and QTL Analysis for Trunk Diameter.

    Science.gov (United States)

    Wang, Jing; Zhang, Kaichun; Zhang, Xiaoming; Yan, Guohua; Zhou, Yu; Feng, Laibao; Ni, Yang; Duan, Xuwei

    2015-01-01

    A cross between the sweet cherry (Prunus avium) cultivars 'Wanhongzhu' and 'Lapins' was performed to create a mapping population suitable for the construction of a linkage map. The specific-locus amplified fragment (SLAF) sequencing technique used as a single nucleotide polymorphism (SNP) discovery platform and generated 701 informative genotypic assays; these, along with 16 microsatellites (SSRs) and the incompatibility (S) gene, were used to build a map which comprised 8 linkage groups (LGs) and covered a genetic distance of 849.0 cM. The mean inter-marker distance was 1.18 cM and there were few gaps > 5 cM in length. Marker collinearity was maintained with the established peach genomic sequence. The map was used to show that trunk diameter (TD) is under the control of 4 loci, mapping to 3 different LGs. Different locus influenced TD at a varying stage of the tree's development. The high density 'W×L' genetic linkage map has the potential to enable high-resolution identification of QTLs of agronomically relevant traits, and accelerate sweet cherry breeding.

  5. Construction of Commercial Sweet Cherry Linkage Maps and QTL Analysis for Trunk Diameter.

    Directory of Open Access Journals (Sweden)

    Jing Wang

    Full Text Available A cross between the sweet cherry (Prunus avium cultivars 'Wanhongzhu' and 'Lapins' was performed to create a mapping population suitable for the construction of a linkage map. The specific-locus amplified fragment (SLAF sequencing technique used as a single nucleotide polymorphism (SNP discovery platform and generated 701 informative genotypic assays; these, along with 16 microsatellites (SSRs and the incompatibility (S gene, were used to build a map which comprised 8 linkage groups (LGs and covered a genetic distance of 849.0 cM. The mean inter-marker distance was 1.18 cM and there were few gaps > 5 cM in length. Marker collinearity was maintained with the established peach genomic sequence. The map was used to show that trunk diameter (TD is under the control of 4 loci, mapping to 3 different LGs. Different locus influenced TD at a varying stage of the tree's development. The high density 'W×L' genetic linkage map has the potential to enable high-resolution identification of QTLs of agronomically relevant traits, and accelerate sweet cherry breeding.

  6. A robust linkage map of the porcine autosome based on gene-associated SNPs

    DEFF Research Database (Denmark)

    Vingborg, Rikke K K; Gregersen, Vivi R; Zhan, Bujie;

    2009-01-01

    Background Genetic linkage maps are necessary for mapping of mendelian traits and quantitative trait loci (QTLs). To identify the actual genes, which control these traits, a map based on gene-associated single nucleotide polymorphism (SNP) markers is highly valuable. In this study, the SNPs were...... genotyped in a large family material comprising more than 5,000 piglets derived from 12 Duroc boars crossed with 236 Danish Landrace/Danish Large White sows. The SNPs were identified in sequence alignments of 4,600 different amplicons obtained from the 12 boars and containing coding regions of genes derived...... from expressed sequence tags (ESTs) and genomic shotgun sequences. Results Linkage maps of all 18 porcine autosomes were constructed based on 456 gene-associated and six porcine EST-based SNPs. The total length of the averaged-sex whole porcine autosome was estimated to 1,711.8 cM resulting...

  7. An integrated restriction fragment length polymorphism--amplified fragment length polymorphism linkage map for cultivated sunflower.

    Science.gov (United States)

    Gedil, M A; Wye, C; Berry, S; Segers, B; Peleman, J; Jones, R; Leon, A; Slabaugh, M B; Knapp, S J

    2001-04-01

    Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflower (Helianthus annuus L.) using three independent sets of RFLP probes. The aim of this research was to integrate RFLP markers from two sets with RFLP markers for resistance gene candidate (RGC) and amplified fragment length polymorphism (AFLP) markers. Genomic DNA samples of HA370 and HA372, the parents of the F2 population used to build the map, were screened for AFLPs using 42 primer combinations and RFLPs using 136 cDNA probes (RFLP analyses were performed on DNA digested with EcoRI, HindIII, EcoRV, or DraI). The AFLP primers produced 446 polymorphic and 1101 monomorphic bands between HA370 and HA372. The integrated map was built by genotyping 296 AFLP and 104 RFLP markers on 180 HA370 x HA372 F2 progeny (the AFLP marker assays were performed using 18 primer combinations). The HA370 x HA372 map comprised 17 linkage groups, presumably corresponding to the 17 haploid chromosomes of sunflower, had a mean density of 3.3 cM, and was 1326 cM long. Six RGC RFLP loci were polymorphic and mapped to three linkage groups (LG8, LG13, and LG15). AFLP markers were densely clustered on several linkage groups, and presumably reside in centromeric regions where recombination is reduced and the ratio of genetic to physical distance is low. Strategies for targeting markers to euchromatic DNA need to be tested in sunflower. The HA370 x HA372 map integrated 14 of 17 linkage groups from two independent RFLP maps. Three linkage groups were devoid of RFLP markers from one of the two maps.

  8. Identifying trait clusters by linkage profiles: application in genetical genomics.

    Science.gov (United States)

    Sampson, Joshua N; Self, Steven G

    2008-04-01

    Genes often regulate multiple traits. Identifying clusters of traits influenced by a common group of genes helps elucidate regulatory networks and can improve linkage mapping. We show that the Pearson correlation coefficient, rho L, between two LOD score profiles can, with high specificity and sensitivity, identify pairs of genes that have their transcription regulated by shared quantitative trait loci (QTL). Furthermore, using theoretical and/or empirical methods, we can approximate the distribution of rho L under the null hypothesis of no common QTL. Therefore, it is possible to calculate P-values and false discovery rates for testing whether two traits share common QTL. We then examine the properties of rho L through simulation and use rho L to cluster genes in a genetical genomics experiment examining Saccharomyces cerevisiae. Simulations show that rho L can have more power than the clustering methods currently used in genetical genomics. Combining experimental results with Gene Ontology (GO) annotations show that genes within a purported cluster often share similar function. R-code included in online Supplementary Material.

  9. Fine mapping of multiple interacting quantitative trait loci using combined linkage disequilibrium and linkage information

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Quantitative trait loci (QTL) and their additive, dominance and epistatic effects play a critical role in complex trait variation. It is often infeasible to detect multiple interacting QTL due to main effects often being confounded by interaction effects.Positioning interacting QTL within a small region is even more difficult. We present a variance component approach nested in an empirical Bayesian method, which simultaneously takes into account additive, dominance and epistatic effects due to multiple interacting QTL. The covariance structure used in the variance component approach is based on combined linkage disequilibrium and linkage (LDL) information. In a simulation study where there are complex epistatic interactions between QTL, it is possible to simultaneously fine map interacting QTL using the proposed approach. The present method combined with LDL information can efficiently detect QTL and their dominance and epistatic effects, making it possible to simultaneously fine map main and epistatic QTL.

  10. Indication of Genetic Linkage Map for Sunflower by SSR Markers%SSR分子标记丰富向日葵(Helianthus annuus L.)遗传图谱的研究

    Institute of Scientific and Technical Information of China (English)

    黄先群; Genzbitelle L.; Fabre F.; Saraffi A.

    2012-01-01

    为了提高向日葵遗传图谱的密度和实用性,以125个来源于PAC-2和RHA-266杂交的F(8)代重组自交系(RIIs)群体为材料,利用筒单序列重复(Simple sequence repeat,SSR)标记,采用MAPMARKER软件对向日英遗传图谱进行标注,并从300对SSR引物中筛选出51对多态性引物对群体进行标记.结果表明:①51对多态性引物中有19对引物无多态性或条带不清晰,32对引物表现多态性;②共检测到35个多态性位点,分布在图谱的15条连锁群上.③标记后的图谱总长度为2914.5 Cm,比原来的图谱增长7.5 Cm.④标记间平均距离由9.0 Cm缩短为8.1 Cm.%This study aimed to improve density and practicality of the genetic map of sunflower baaed on a 125 Fs RILa population derived from a cross between PAC-2 and RHA-266 by adding some SSR markers. A total of 300 pairs of SSR primers were used to screen polymorphic markers between the parents and some of their RILs, of which 51 pain of the primers showed polymorphism. The results of screening the RILs population revealed that 19 SSR primer without polymorphism or non-reading, 32 SSR pairs showed polymorphism with 35 alleles added into the map. They were distributed in the 15 linkage groups of the maps. The new map covered a total length of 2914.5 cM, 7.5 cM longer than the original map. The average distance between adjacent markers was 8.1 cM instead of original 9.0 cM.

  11. Unidimensional nonnegative scaling for genome-wide linkage disequilibrium maps.

    Science.gov (United States)

    Liao, Haiyong; Ng, Michael; Fung, Eric; Sham, Pak C

    2008-01-01

    The main aim of this paper is to propose and develop a unidimensional nonnegative scaling model to construct Linkage Disequilibrium (LD) maps. The proposed constrained scaling model can be efficiently solved by transforming it to an unconstrained model. The method is implemented in PC Clusters at Hong Kong Baptist University. The LD maps are constructed for four populations from Hapmap data sets with chromosomes of several ten thousand Single Nucleotide Polymorphisms (SNPs). The similarities and dissimilarities of the LD maps are studied and analysed. Computational results are also reported to show the effectiveness of the method using parallel computation.

  12. A sequencing-based linkage map of cucumber

    Science.gov (United States)

    Genetic maps are important tools for molecular breeding, gene cloning, and study of meiotic recombination. In cucumber (Cucumis sativus L.), the marker density, resolution and genome coverage of previously developed genetic maps using PCR-based molecular markers are relatively low. In this study we ...

  13. Construction of an SSR and RAD-Marker Based Molecular Linkage Map of Vigna vexillata (L.) A. Rich.

    Science.gov (United States)

    Marubodee, Rusama; Ogiso-Tanaka, Eri; Isemura, Takehisa; Chankaew, Sompong; Kaga, Akito; Naito, Ken; Ehara, Hiroshi; Tomooka, Norihiko

    2015-01-01

    Vigna vexillata (L.) A. Rich. (tuber cowpea) is an underutilized crop for consuming its tuber and mature seeds. Wild form of V. vexillata is a pan-tropical perennial herbaceous plant which has been used by local people as a food. Wild V. vexillata has also been considered as useful gene(s) source for V. unguiculata (cowpea), since it was reported to have various resistance gene(s) for insects and diseases of cowpea. To exploit the potential of V. vexillata, an SSR-based linkage map of V. vexillata was developed. A total of 874 SSR markers successfully amplified single DNA fragment in V. vexillata among 1,336 SSR markers developed from Vigna angularis (azuki bean), V. unguiculata and Phaseolus vulgaris (common bean). An F2 population of 300 plants derived from a cross between salt resistant (V1) and susceptible (V5) accessions was used for mapping. A genetic linkage map was constructed using 82 polymorphic SSR markers loci, which could be assigned to 11 linkage groups spanning 511.5 cM in length with a mean distance of 7.2 cM between adjacent markers. To develop higher density molecular linkage map and to confirm SSR markers position in a linkage map, RAD markers were developed and a combined SSR and RAD markers linkage map of V. vexillata was constructed. A total of 559 (84 SSR and 475 RAD) markers loci could be assigned to 11 linkage groups spanning 973.9 cM in length with a mean distance of 1.8 cM between adjacent markers. Linkage and genetic position of all SSR markers in an SSR linkage map were confirmed. When an SSR genetic linkage map of V. vexillata was compared with those of V. radiata and V. unguiculata, it was suggested that the structure of V. vexillata chromosome was considerably differentiated. This map is the first SSR and RAD marker-based V. vexillata linkage map which can be used for the mapping of useful traits.

  14. Construction of an SSR and RAD-Marker Based Molecular Linkage Map of Vigna vexillata (L. A. Rich.

    Directory of Open Access Journals (Sweden)

    Rusama Marubodee

    Full Text Available Vigna vexillata (L. A. Rich. (tuber cowpea is an underutilized crop for consuming its tuber and mature seeds. Wild form of V. vexillata is a pan-tropical perennial herbaceous plant which has been used by local people as a food. Wild V. vexillata has also been considered as useful gene(s source for V. unguiculata (cowpea, since it was reported to have various resistance gene(s for insects and diseases of cowpea. To exploit the potential of V. vexillata, an SSR-based linkage map of V. vexillata was developed. A total of 874 SSR markers successfully amplified single DNA fragment in V. vexillata among 1,336 SSR markers developed from Vigna angularis (azuki bean, V. unguiculata and Phaseolus vulgaris (common bean. An F2 population of 300 plants derived from a cross between salt resistant (V1 and susceptible (V5 accessions was used for mapping. A genetic linkage map was constructed using 82 polymorphic SSR markers loci, which could be assigned to 11 linkage groups spanning 511.5 cM in length with a mean distance of 7.2 cM between adjacent markers. To develop higher density molecular linkage map and to confirm SSR markers position in a linkage map, RAD markers were developed and a combined SSR and RAD markers linkage map of V. vexillata was constructed. A total of 559 (84 SSR and 475 RAD markers loci could be assigned to 11 linkage groups spanning 973.9 cM in length with a mean distance of 1.8 cM between adjacent markers. Linkage and genetic position of all SSR markers in an SSR linkage map were confirmed. When an SSR genetic linkage map of V. vexillata was compared with those of V. radiata and V. unguiculata, it was suggested that the structure of V. vexillata chromosome was considerably differentiated. This map is the first SSR and RAD marker-based V. vexillata linkage map which can be used for the mapping of useful traits.

  15. A Linkage Map and QTL Analysis for Pyrethroid Resistance in the Bed Bug Cimex lectularius.

    Science.gov (United States)

    Fountain, Toby; Ravinet, Mark; Naylor, Richard; Reinhardt, Klaus; Butlin, Roger K

    2016-12-07

    The rapid evolution of insecticide resistance remains one of the biggest challenges in the control of medically and economically important pests. Insects have evolved a diverse range of mechanisms to reduce the efficacy of the commonly used classes of insecticides, and finding the genetic basis of resistance is a major aid to management. In a previously unstudied population, we performed an F2 resistance mapping cross for the common bed bug, Cimex lectularius, for which insecticide resistance is increasingly widespread. Using 334 SNP markers obtained through RAD-sequencing, we constructed the first linkage map for the species, consisting of 14 putative linkage groups (LG), with a length of 407 cM and an average marker spacing of 1.3 cM. The linkage map was used to reassemble the recently published reference genome, facilitating refinement and validation of the current genome assembly. We detected a major QTL on LG12 associated with insecticide resistance, occurring in close proximity (1.2 Mb) to a carboxylesterase encoding candidate gene for pyrethroid resistance. This provides another example of this candidate gene playing a major role in determining survival in a bed bug population following pesticide resistance evolution. The recent availability of the bed bug genome, complete with a full list of potential candidate genes related to insecticide resistance, in addition to the linkage map generated here, provides an excellent resource for future research on the development and spread of insecticide resistance in this resurging pest species. Copyright © 2016 Fountain et al.

  16. A Linkage Map and QTL Analysis for Pyrethroid Resistance in the Bed Bug Cimex lectularius

    Directory of Open Access Journals (Sweden)

    Toby Fountain

    2016-12-01

    Full Text Available The rapid evolution of insecticide resistance remains one of the biggest challenges in the control of medically and economically important pests. Insects have evolved a diverse range of mechanisms to reduce the efficacy of the commonly used classes of insecticides, and finding the genetic basis of resistance is a major aid to management. In a previously unstudied population, we performed an F2 resistance mapping cross for the common bed bug, Cimex lectularius, for which insecticide resistance is increasingly widespread. Using 334 SNP markers obtained through RAD-sequencing, we constructed the first linkage map for the species, consisting of 14 putative linkage groups (LG, with a length of 407 cM and an average marker spacing of 1.3 cM. The linkage map was used to reassemble the recently published reference genome, facilitating refinement and validation of the current genome assembly. We detected a major QTL on LG12 associated with insecticide resistance, occurring in close proximity (1.2 Mb to a carboxylesterase encoding candidate gene for pyrethroid resistance. This provides another example of this candidate gene playing a major role in determining survival in a bed bug population following pesticide resistance evolution. The recent availability of the bed bug genome, complete with a full list of potential candidate genes related to insecticide resistance, in addition to the linkage map generated here, provides an excellent resource for future research on the development and spread of insecticide resistance in this resurging pest species.

  17. A Linkage Map and QTL Analysis for Pyrethroid Resistance in the Bed Bug Cimex lectularius

    Science.gov (United States)

    Fountain, Toby; Ravinet, Mark; Naylor, Richard; Reinhardt, Klaus; Butlin, Roger K.

    2016-01-01

    The rapid evolution of insecticide resistance remains one of the biggest challenges in the control of medically and economically important pests. Insects have evolved a diverse range of mechanisms to reduce the efficacy of the commonly used classes of insecticides, and finding the genetic basis of resistance is a major aid to management. In a previously unstudied population, we performed an F2 resistance mapping cross for the common bed bug, Cimex lectularius, for which insecticide resistance is increasingly widespread. Using 334 SNP markers obtained through RAD-sequencing, we constructed the first linkage map for the species, consisting of 14 putative linkage groups (LG), with a length of 407 cM and an average marker spacing of 1.3 cM. The linkage map was used to reassemble the recently published reference genome, facilitating refinement and validation of the current genome assembly. We detected a major QTL on LG12 associated with insecticide resistance, occurring in close proximity (1.2 Mb) to a carboxylesterase encoding candidate gene for pyrethroid resistance. This provides another example of this candidate gene playing a major role in determining survival in a bed bug population following pesticide resistance evolution. The recent availability of the bed bug genome, complete with a full list of potential candidate genes related to insecticide resistance, in addition to the linkage map generated here, provides an excellent resource for future research on the development and spread of insecticide resistance in this resurging pest species. PMID:27733453

  18. High-resolution gene mapping using admixture linkage disequilibrium

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This note reports simulation study on the rate of decay in linkage dis equilibrium (LD) in mixed populations over multiple discrete generations and explores the usefulness of the LD analysis in high-resolution gene mapping. The results indicate that the smaller the recombination fraction and the fewer generati ons since admixtureevent, the higher power of the approach in gene mapping. The expected estimate of recombination fraction would give an estimate that is slig htly biased upwards, if relevant genes are in tight linkage. The estimated recom bination fraction is usually larger than the true value within 2-5 generations. From generations 10-20, the mean estimates are in good agreement with the true value. The method presented here enables estimation of means and corresponding confidence intervals of the recombination fraction at any number of generations.

  19. Linear models for joint association and linkage QTL mapping

    Directory of Open Access Journals (Sweden)

    Fernando Rohan L

    2009-09-01

    Full Text Available Abstract Background Populational linkage disequilibrium and within-family linkage are commonly used for QTL mapping and marker assisted selection. The combination of both results in more robust and accurate locations of the QTL, but models proposed so far have been either single marker, complex in practice or well fit to a particular family structure. Results We herein present linear model theory to come up with additive effects of the QTL alleles in any member of a general pedigree, conditional to observed markers and pedigree, accounting for possible linkage disequilibrium among QTLs and markers. The model is based on association analysis in the founders; further, the additive effect of the QTLs transmitted to the descendants is a weighted (by the probabilities of transmission average of the substitution effects of founders' haplotypes. The model allows for non-complete linkage disequilibrium QTL-markers in the founders. Two submodels are presented: a simple and easy to implement Haley-Knott type regression for half-sib families, and a general mixed (variance component model for general pedigrees. The model can use information from all markers. The performance of the regression method is compared by simulation with a more complex IBD method by Meuwissen and Goddard. Numerical examples are provided. Conclusion The linear model theory provides a useful framework for QTL mapping with dense marker maps. Results show similar accuracies but a bias of the IBD method towards the center of the region. Computations for the linear regression model are extremely simple, in contrast with IBD methods. Extensions of the model to genomic selection and multi-QTL mapping are straightforward.

  20. Development of gene-based markers for use in construction of the chickpea (Cicer arietinum L.) genetic linkage map and identification of QTLs associated with seed weight and plant height.

    Science.gov (United States)

    Gupta, Shefali; Kumar, Tapan; Verma, Subodh; Bharadwaj, Chellapilla; Bhatia, Sabhyata

    2015-11-01

    Seed weight and plant height are important agronomic traits and contribute to seed yield. The objective of this study was to identify QTLs underlying these traits using an intra-specific mapping population of chickpea. A F11 population of 177 recombinant inbred lines derived from a cross between SBD377 (100-seed weight--48 g and plant height--53 cm) and BGD112 (100-seed weight--15 g and plant height--65 cm) was used. A total of 367 novel EST-derived functional markers were developed which included 187 EST-SSRs, 130 potential intron polymorphisms (PIPs) and 50 expressed sequence tag polymorphisms (ESTPs). Along with these, 590 previously published markers including 385 EST-based markers and 205 genomic SSRs were utilized. Of the 957 markers tested for analysis of parental polymorphism between the two parents of the mapping population, 135 (14.64%) were found to be polymorphic. Of these, 131 polymorphic markers could be mapped to the 8 linkage groups. The linkage map had a total length of 1140.54 cM with an average marker density of 8.7 cM. The map was further used for QTL identification using composite interval mapping method (CIM). Two QTLs each for seed weight, qSW-1 and qSW-2 (explaining 11.54 and 19.24% of phenotypic variance, respectively) and plant height, qPH-1 and qPH-2 (explaining 13.98 and 12.17% of phenotypic variance, respectively) were detected. The novel set of genic markers, the intra-specific linkage map and the QTLs identified in the present study will serve as valuable genomic resources in improving the chickpea seed yield using marker-assisted selection (MAS) strategies.

  1. Exploring a Nonmodel Teleost Genome Through RAD Sequencing—Linkage Mapping in Common Pandora, Pagellus erythrinus and Comparative Genomic Analysis

    OpenAIRE

    Tereza Manousaki; Alexandros Tsakogiannis; Taggart, John B.; Christos Palaiokostas; Dimitris Tsaparis; Jacques Lagnel; Dimitrios Chatziplis; Antonios Magoulas; Nikos Papandroulakis; Mylonas, Constantinos C.; Tsigenopoulos, Costas S

    2016-01-01

    Common pandora (Pagellus erythrinus) is a benthopelagic marine fish belonging to the teleost family Sparidae, and a newly recruited species in Mediterranean aquaculture. The paucity of genetic information relating to sparids, despite their growing economic value for aquaculture, provides the impetus for exploring the genomics of this fish group. Genomic tool development, such as genetic linkage maps provision, lays the groundwork for linking the genotype to phenotype allowing fine-mapping of ...

  2. Mapping multiple QTL using linkage disequilibrium and linkage analysis information and multitrait data

    Directory of Open Access Journals (Sweden)

    Goddard Mike E

    2004-05-01

    Full Text Available Abstract A multi-locus QTL mapping method is presented, which combines linkage and linkage disequilibrium (LD information and uses multitrait data. The method assumed a putative QTL at the midpoint of each marker bracket. Whether the putative QTL had an effect or not was sampled using Markov chain Monte Carlo (MCMC methods. The method was tested in dairy cattle data on chromosome 14 where the DGAT1 gene was known to be segregating. The DGAT1 gene was mapped to a region of 0.04 cM, and the effects of the gene were accurately estimated. The fitting of multiple QTL gave a much sharper indication of the QTL position than a single QTL model using multitrait data, probably because the multi-locus QTL mapping reduced the carry over effect of the large DGAT1 gene to adjacent putative QTL positions. This suggests that the method could detect secondary QTL that would, in single point analyses, remain hidden under the broad peak of the dominant QTL. However, no indications for a second QTL affecting dairy traits were found on chromosome 14.

  3. Saturated linkage map construction in Rubus idaeus using genotyping by sequencing and genome-independent imputation

    Directory of Open Access Journals (Sweden)

    Ward Judson A

    2013-01-01

    Full Text Available Abstract Background Rapid development of highly saturated genetic maps aids molecular breeding, which can accelerate gain per breeding cycle in woody perennial plants such as Rubus idaeus (red raspberry. Recently, robust genotyping methods based on high-throughput sequencing were developed, which provide high marker density, but result in some genotype errors and a large number of missing genotype values. Imputation can reduce the number of missing values and can correct genotyping errors, but current methods of imputation require a reference genome and thus are not an option for most species. Results Genotyping by Sequencing (GBS was used to produce highly saturated maps for a R. idaeus pseudo-testcross progeny. While low coverage and high variance in sequencing resulted in a large number of missing values for some individuals, a novel method of imputation based on maximum likelihood marker ordering from initial marker segregation overcame the challenge of missing values, and made map construction computationally tractable. The two resulting parental maps contained 4521 and 2391 molecular markers spanning 462.7 and 376.6 cM respectively over seven linkage groups. Detection of precise genomic regions with segregation distortion was possible because of map saturation. Microsatellites (SSRs linked these results to published maps for cross-validation and map comparison. Conclusions GBS together with genome-independent imputation provides a rapid method for genetic map construction in any pseudo-testcross progeny. Our method of imputation estimates the correct genotype call of missing values and corrects genotyping errors that lead to inflated map size and reduced precision in marker placement. Comparison of SSRs to published R. idaeus maps showed that the linkage maps constructed with GBS and our method of imputation were robust, and marker positioning reliable. The high marker density allowed identification of genomic regions with segregation

  4. Linkage mapping of the human CSF2 and IL3 genes

    Energy Technology Data Exchange (ETDEWEB)

    Frolova, E.I.; Dolganov, G.M.; Mazo, I.A.; Smirnov, D.V. (M.M. Shemyakin Inst. of Bio-organic Chemistry, Moscow (USSR)); Copeland, P.; Stewart, C.; Dean, M. (Program Resources, Inc./DynCorp., Research Triangle Park, NC (United States)); O' Brien, S.J. (National Cancer Inst., Frederick, MD (United States))

    1991-06-01

    Interleukin 3 (encoded by the IL3 gene) and granulocyte-macrophage colony-stimulating factor (encoded by the CSF2 gene) are small secreted polypeptides that bind to specific cell surface receptors and regulate the growth, gene expression, and differentiation of many of the hematopoietic cell lineages, particularly nonlymphoid cells. The IL3 and CSF2 genes have been cloned and mapped to human chromosome bands 5q23-31. Only 10 kilobases of dna separates the two genes, suggesting that they have a common origin and/or regulation. The authors have cloned 70 kilobases of genomic DNA that includes the IL3 and CSF2 genes, as well as flanking sequences, and report a physical map of this region. Several unique-sequence DNA segments have been identified in this region, and one of these fragments detects two restriction fragment length polymorphisms in DNA from unrelated Caucasians. Segregation of these DNA polymorphisms was followed in the Centre Etude du Polymorphisme Humaine (CEPH) panel of 40 large three-generation pedigrees, and linkage was detected with 17 genetic markers previously typed in these families. Multipoint linkage analysis permits the placement of the region containing the IL3 and CSF2 structural genes on the recombination-genetic linkage map of chromosome 5q and thereby allows the role of these genes in leukemogenesis to be more critically examined.

  5. Linkage intensity learning approach with genetic algorithm for causality diagram

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng-liang; CHEN Juan-juan

    2007-01-01

    The causality diagram theory, which adopts graphical expression of knowledge and direct intensity of causality, overcomes some shortages in belief network and has evolved into a mixed causality diagram methodology for discrete and continuous variable. But to give linkage intensity of causality diagram is difficult, particularly in many working conditions in which sampling data are limited or noisy. The classic learning algorithm is hard to be adopted. We used genetic algorithm to learn linkage intensity from limited data. The simulation results demonstrate that this algorithm is more suitable than the classic algorithm in the condition of sample shortage such as space shuttle's fault diagnoisis.

  6. The first linkage map of the American mink (Mustela vison)

    DEFF Research Database (Denmark)

    Anistoroaei, Razvan Marian; Menzorov, A.; Serov, O.

    2007-01-01

    Described herein, the first microsatellite linkage map for the American mink consists of 85 microsatellite markers resolved into 17 linkage groups. The map was constructed using 92 F1 progeny from five sire families created by crossing mink with different colour types. The linkage groups ranged...

  7. Joint QTL linkage mapping for multiple-cross mating design sharing one common parent.

    Directory of Open Access Journals (Sweden)

    Huihui Li

    Full Text Available BACKGROUND: Nested association mapping (NAM is a novel genetic mating design that combines the advantages of linkage analysis and association mapping. This design provides opportunities to study the inheritance of complex traits, but also requires more advanced statistical methods. In this paper, we present the detailed algorithm of a QTL linkage mapping method suitable for genetic populations derived from NAM designs. This method is called joint inclusive composite interval mapping (JICIM. Simulations were designed on the detected QTL in a maize NAM population and an Arabidopsis NAM population so as to evaluate the efficiency of the NAM design and the JICIM method. PRINCIPAL FINDINGS: Fifty-two QTL were identified in the maize population, explaining 89% of the phenotypic variance of days to silking, and nine QTL were identified in the Arabidopsis population, explaining 83% of the phenotypic variance of flowering time. Simulations indicated that the detection power of these identified QTL was consistently high, especially for large-effect QTL. For rare QTL having significant effects in only one family, the power of correct detection within the 5 cM support interval was around 80% for 1-day effect QTL in the maize population, and for 3-day effect QTL in the Arabidopsis population. For smaller-effect QTL, the power diminished, e.g., it was around 50% for maize QTL with an effect of 0.5 day. When QTL were linked at a distance of 5 cM, the likelihood of mapping them as two distinct QTL was about 70% in the maize population. When the linkage distance was 1 cM, they were more likely mapped as one single QTL at an intermediary position. CONCLUSIONS: Because it takes advantage of the large genetic variation among parental lines and the large population size, NAM is a powerful multiple-cross design for complex trait dissection. JICIM is an efficient and specialty method for the joint QTL linkage mapping of genetic populations derived from the NAM design.

  8. Estimation of recombination frequency in genetic linkage studies.

    Science.gov (United States)

    Nordheim, E V; O'Malley, D M; Guries, R P

    1983-09-01

    A binomial-like model is developed that may be used in genetic linkage studies when data are generated by a testcross with parental phase unknown. Four methods of estimation for the recombination frequency are compared for data from a single group and also from several groups; these methods are maximum likelihood, two Bayesian procedures, and an ad hoc technique. The Bayes estimator using a noninformative prior usually has a lower mean squared error than the other estimators and because of this it is the recommended estimator. This estimator appears particularly useful for estimation of recombination frequencies indicative of weak linkage from samples of moderate size. Interval estimates corresponding to this estimator can be obtained numerically by discretizing the posterior distribution, thereby providing researchers with a range of plausible recombination values. Data from a linkage study on pitch pine are used as an example.

  9. Construction of microsatellite-based linkage map and mapping of nectarilessness and hairiness genes in Gossypium tomentosum

    Indian Academy of Sciences (India)

    Meiying Hou; Caiping Cai; Shuwen Zhang; Wangzhen Guo; Tianzhen Zhang; Baoliang Zhou

    2013-12-01

    Gossypium tomentosum, a wild tetraploid cotton species with AD genomes, possesses genes conferring strong fibers and high heat tolerance. To effectively transfer these genes into Gossypium hirsutum, an entire microsatellite (simple sequence repeat, SSR)-based genetic map was constructed using the interspecific cross of G. hirsutum × G. tomentosum (HT). We detected 1800 loci from 1347 pairs of polymorphic primers. Of these, 1204 loci were grouped into 35 linkage groups at LOD ≥4. The map covers 3320.8 cM, with a mean density of 2.76 cM per locus. We detected 420 common loci (186 in the At subgenome and 234 in Dt) between the HT map and the map of TM-1 (G. hirsutum) and Hai 7124 (G. barbadense; HB map). The linkage groups were assigned chromosome numbers based on location of common loci and the HB map as reference. A comparison of common markers revealed that no significant chromosomal rearrangement exist between G. tomentosum and G. barbadense. Interestingly, however, we detected numerous (33.7%) segregation loci deviating from 3:1 ratio ($P \\lt 0.05$) in HT, mostly clustering on eight chromosomes in the Dt subgenome, with some on three chromosomes in At. Two morphological traits, leaf hairiness and leaf nectarilessness were mapped on chromosomes 6 (A6) and 26 (D12), respectively. The SSR-based map constructed in this study will be useful for further genetic studies on cotton breeding, including mapping loci controlling quantitative traits associated with fiber quality, stress tolerance and developing chromosome segment specific introgression lines from G. tomentosum into G. hirsutum using marker-assisted selection.

  10. An EST-SSR linkage map of Raphanus sativus and comparative genomics of the Brassicaceae.

    Science.gov (United States)

    Shirasawa, Kenta; Oyama, Maki; Hirakawa, Hideki; Sato, Shusei; Tabata, Satoshi; Fujioka, Takashi; Kimizuka-Takagi, Chiaki; Sasamoto, Shigemi; Watanabe, Akiko; Kato, Midori; Kishida, Yoshie; Kohara, Mitsuyo; Takahashi, Chika; Tsuruoka, Hisano; Wada, Tsuyuko; Sakai, Takako; Isobe, Sachiko

    2011-08-01

    Raphanus sativus (2n = 2x = 18) is a widely cultivated member of the family Brassicaceae, for which genomic resources are available only to a limited extent in comparison to many other members of the family. To promote more genetic and genomic studies and to enhance breeding programmes of R. sativus, we have prepared genetic resources such as complementary DNA libraries, expressed sequences tags (ESTs), simple sequence repeat (SSR) markers and a genetic linkage map. A total of 26 606 ESTs have been collected from seedlings, roots, leaves, and flowers, and clustered into 10 381 unigenes. Similarities were observed between the expression patterns of transcripts from R. sativus and those from representative members of the genera Arabidopsis and Brassica, indicating their functional relatedness. The EST sequence data were used to design 3800 SSR markers and consequently 630 polymorphic SSR loci and 213 reported marker loci have been mapped onto nine linkage groups, covering 1129.2 cM with an average distance of 1.3 cM between loci. Comparison of the mapped EST-SSR marker positions in R. sativus with the genome sequence of A. thaliana indicated that the Brassicaceae members have evolved from a common ancestor. It appears that genomic fragments corresponding to those of A. thaliana have been doubled and tripled in R. sativus. The genetic map developed here is expected to provide a standard map for the genetics, genomics, and molecular breeding of R. sativus as well as of related species. The resources are available at http://marker.kazusa.or.jp/Daikon.

  11. An integrated genetic and cytogenetic map of the cucumber genome.

    Directory of Open Access Journals (Sweden)

    Yi Ren

    Full Text Available The Cucurbitaceae includes important crops such as cucumber, melon, watermelon, squash and pumpkin. However, few genetic and genomic resources are available for plant improvement. Some cucurbit species such as cucumber have a narrow genetic base, which impedes construction of saturated molecular linkage maps. We report herein the development of highly polymorphic simple sequence repeat (SSR markers originated from whole genome shotgun sequencing and the subsequent construction of a high-density genetic linkage map. This map includes 995 SSRs in seven linkage groups which spans in total 573 cM, and defines approximately 680 recombination breakpoints with an average of 0.58 cM between two markers. These linkage groups were then assigned to seven corresponding chromosomes using fluorescent in situ hybridization (FISH. FISH assays also revealed a chromosomal inversion between Cucumis subspecies [C. sativus var. sativus L. and var. hardwickii (R. Alef], which resulted in marker clustering on the genetic map. A quarter of the mapped markers showed relatively high polymorphism levels among 11 inbred lines of cucumber. Among the 995 markers, 49%, 26% and 22% were conserved in melon, watermelon and pumpkin, respectively. This map will facilitate whole genome sequencing, positional cloning, and molecular breeding in cucumber, and enable the integration of knowledge of gene and trait in cucurbits.

  12. Rapid genotyping with DNA micro-arrays for high-density linkage mapping and QTL mapping in common buckwheat (Fagopyrum esculentum Moench).

    Science.gov (United States)

    Yabe, Shiori; Hara, Takashi; Ueno, Mariko; Enoki, Hiroyuki; Kimura, Tatsuro; Nishimura, Satoru; Yasui, Yasuo; Ohsawa, Ryo; Iwata, Hiroyoshi

    2014-12-01

    For genetic studies and genomics-assisted breeding, particularly of minor crops, a genotyping system that does not require a priori genomic information is preferable. Here, we demonstrated the potential of a novel array-based genotyping system for the rapid construction of high-density linkage map and quantitative trait loci (QTL) mapping. By using the system, we successfully constructed an accurate, high-density linkage map for common buckwheat (Fagopyrum esculentum Moench); the map was composed of 756 loci and included 8,884 markers. The number of linkage groups converged to eight, which is the basic number of chromosomes in common buckwheat. The sizes of the linkage groups of the P1 and P2 maps were 773.8 and 800.4 cM, respectively. The average interval between adjacent loci was 2.13 cM. The linkage map constructed here will be useful for the analysis of other common buckwheat populations. We also performed QTL mapping for main stem length and detected four QTL. It took 37 days to process 178 samples from DNA extraction to genotyping, indicating the system enables genotyping of genome-wide markers for a few hundred buckwheat plants before the plants mature. The novel system will be useful for genomics-assisted breeding in minor crops without a priori genomic information.

  13. Integrated genome sequence and linkage map of physic nut (Jatropha curcas L.), a biodiesel plant.

    Science.gov (United States)

    Wu, Pingzhi; Zhou, Changpin; Cheng, Shifeng; Wu, Zhenying; Lu, Wenjia; Han, Jinli; Chen, Yanbo; Chen, Yan; Ni, Peixiang; Wang, Ying; Xu, Xun; Huang, Ying; Song, Chi; Wang, Zhiwen; Shi, Nan; Zhang, Xudong; Fang, Xiaohua; Yang, Qing; Jiang, Huawu; Chen, Yaping; Li, Meiru; Wang, Ying; Chen, Fan; Wang, Jun; Wu, Guojiang

    2015-03-01

    The family Euphorbiaceae includes some of the most efficient biomass accumulators. Whole genome sequencing and the development of genetic maps of these species are important components in molecular breeding and genetic improvement. Here we report the draft genome of physic nut (Jatropha curcas L.), a biodiesel plant. The assembled genome has a total length of 320.5 Mbp and contains 27,172 putative protein-coding genes. We established a linkage map containing 1208 markers and anchored the genome assembly (81.7%) to this map to produce 11 pseudochromosomes. After gene family clustering, 15,268 families were identified, of which 13,887 existed in the castor bean genome. Analysis of the genome highlighted specific expansion and contraction of a number of gene families during the evolution of this species, including the ribosome-inactivating proteins and oil biosynthesis pathway enzymes. The genomic sequence and linkage map provide a valuable resource not only for fundamental and applied research on physic nut but also for evolutionary and comparative genomics analysis, particularly in the Euphorbiaceae.

  14. An Integrated Map of Soybean Physical Map and Genetic Map

    Institute of Scientific and Technical Information of China (English)

    QI Zhaoming; LI Hui; WU Qiong; SUN Yanan; LIU Chunyan; HU Guohua; CHEN Qingshan

    2009-01-01

    Soybean is a major crop in the world, and it is a main source of plant proteins and oil. A lot of soybean genetic maps and physical maps have been constructed, but there are no integrated map between soybean physical map and genetic map. In this study, soybean genome sequence data, released by JGI (US Department of Energy's Joint Genome Institute), had been downloaded. With the software Blast 2.2.16, a total of 161 super sequences were mapped on the soybean public genetic map to construct an integrated map. The length of these super sequences accounted for 73.08% of all the genome sequence. This integrated map could be used for gene cloning, gene mining, and comparative genome of legume.

  15. Complete the Blank Section with SSR Markers on Linkage Group C1 of Public Genetic Map in Soybean%大豆公共遗传图谱C1连锁群SSR标记空白区段的填补

    Institute of Scientific and Technical Information of China (English)

    雷雅坤; 闫龙; 杨春燕; 宋晓昆; 张孟臣; 黄占景

    2012-01-01

    为进一步饱和大豆公共图谱SSR标记,以大豆育成品种冀豆12×地方品种ZDD03651组合的211个F6株系为作图群体,以Kosambi作图函数构建SSR标记遗传连锁图谱.结果表明,栽培大豆冀豆12与大豆地方品种ZDD03651间SSR标记多态率为44.6%,遗传图谱包含21个连锁群,117个SSR标记,遗传距离总长度1 501 cM,标记间平均距离15.6 cM,其中包含8个偏分离标记.与公共遗传图谱相比,位点间排列顺序、遗传距离和偏分离位点比例基本相同.将SSR新标记Barcsoyssr_4_1181、Barcsoyssr_4_1201、Barcsoyssr_4_1235和Barcsoyssr_5_1266整合到C1连锁群上,填补了国际大豆公共遗传图谱中C1连锁群94.62 ~120.12 cM之间的SSR标记空白区段.%Cross was made using bred varieties Jidou 12 × landrace soybean ZDD03651 ,get F6 RIL population with 211 single plants as the mapping population, construction of a SSR genetic linkage map with Kosambi mapping function, In order to saturate with SSR markers on public genetic map in the further. The polymorphic ratio was 44. 6% of SSR markers between Jidou 12 and ZDD03651. A total of 117 pairs of SSR markers on genetic linkage map,including 8 pairs distorted SSR markers,The resulting genetic linkage map covered 1 501 cM,with an average inter-marker distance of 15.6 cM, including 21 linkage groups. Compared with public genetic map, the order between points, genetic distance and the proportion of distorted markers basically the same. And eventually the development of new molecular markers Barcsoyssr_4_l 181 , Barcsoyssr_4_1201, Barcsoyssr_4_1235 , Barcsoyssr_5_1266 linked to the Cl linkage map,in order to complete the blank section on linkage group Cl between 94.62 cM and 120. 12 cM in the international.

  16. An extended anchored linkage map and virtual mapping for the american mink genome based on homology to human and dog

    DEFF Research Database (Denmark)

    Anistoroaei, Razvan Marian; Ansari, S.; Farid, A.;

    2009-01-01

    In this report we present an extended linkage map of the American mink (Neovison vison) consisting of 157 microsatellite markers and comprising at least one linkage group for each of the autosomes. Each linkage group has been assigned to a chromosome and oriented by fluorescence in situ hybridiza......In this report we present an extended linkage map of the American mink (Neovison vison) consisting of 157 microsatellite markers and comprising at least one linkage group for each of the autosomes. Each linkage group has been assigned to a chromosome and oriented by fluorescence in situ...... comparative human/dog/mink data, these assignments represent useful virtual maps for the American mink genome. Comparison of the current human/dog assembled sequential map with the existing Zoo-FISH-based human/dog/mink maps helped to refine the human/dog/mink comparative map. Furthermore, comparison...

  17. Linkage disequilibrium interval mapping of quantitative trait loci

    Directory of Open Access Journals (Sweden)

    de Rochambeau Hubert

    2006-03-01

    Full Text Available Abstract Background For many years gene mapping studies have been performed through linkage analyses based on pedigree data. Recently, linkage disequilibrium methods based on unrelated individuals have been advocated as powerful tools to refine estimates of gene location. Many strategies have been proposed to deal with simply inherited disease traits. However, locating quantitative trait loci is statistically more challenging and considerable research is needed to provide robust and computationally efficient methods. Results Under a three-locus Wright-Fisher model, we derived approximate expressions for the expected haplotype frequencies in a population. We considered haplotypes comprising one trait locus and two flanking markers. Using these theoretical expressions, we built a likelihood-maximization method, called HAPim, for estimating the location of a quantitative trait locus. For each postulated position, the method only requires information from the two flanking markers. Over a wide range of simulation scenarios it was found to be more accurate than a two-marker composite likelihood method. It also performed as well as identity by descent methods, whilst being valuable in a wider range of populations. Conclusion Our method makes efficient use of marker information, and can be valuable for fine mapping purposes. Its performance is increased if multiallelic markers are available. Several improvements can be developed to account for more complex evolution scenarios or provide robust confidence intervals for the location estimates.

  18. HaploSNP affinities and linkage map positions illuminate subgenome composition in the octoploid, cultivated strawberry (Fragaria×ananassa).

    Science.gov (United States)

    Sargent, D J; Yang, Y; Šurbanovski, N; Bianco, L; Buti, M; Velasco, R; Giongo, L; Davis, T M

    2016-01-01

    The cultivated strawberry, Fragaria×ananassa possesses a genetically complex allo-octoploid genome. Advances in genomics research in Fragaria, including the release of a genome sequence for F. vesca, have permitted the development of a high throughput whole genome genotyping array for strawberry, which promises to facilitate genetics and genomics research. In this investigation, we used the Axiom® IStraw90®)array for linkage map development, and produced a linkage map containing 8,407 SNP markers spanning 1,820cM. Whilst the linkage map provides good coverage of the genome of both parental genotypes, the map of 'Monterey' contained significantly fewer mapped markers than did that of 'Darselect'. The array contains a novel marker class known as haploSNPs, which exploit homoeologous sequence variants as probe destabilization sites to effectively reduce marker ploidy. We examined these sites as potential indicators of subgenomic identities by using comparisons to allele states in two ancestral diploids. On this basis, haploSNP loci could be inferred to be derived from F. vesca, F. iinumae, or from an unknown source. When the identity classifications of haploSNPs were considered in conjunction with their respective linkage map positions, it was possible to define two discrete subgenomes, while the remaining homoeologues of each chromosome could not be partitioned into two discrete subgenomic groupings. These findings suggested a novel hypothesis regarding octoploid strawberry subgenome structure and evolutionary origins.

  19. A linkage map of mouse chromosome 8: further definition of homologous linkage relationships between mouse chromosome 8 and human chromosomes 8, 16, and 19.

    Science.gov (United States)

    Howard, T A; Rochelle, J M; Saunders, A M; Seldin, M F

    1991-05-01

    Using an interspecific cross, a mouse chromosome 8 linkage map spanning 72 cM has been defined by the segregation of restriction fragment length variants. Linkage and genetic distance were established for 10 loci by analysis of 114 meiotic events and indicated the following gene order: (centromere)-Insr-3.5 cM-Plat-26.3 cM-Crryps/Mel/Jund-3.5 cM-Junb/Ucp-10.5 cM-Mt-1-27.2 cM-Acta2-0.9 cM-Aprt. These data provide further definition of mouse chromosome 8 linkage relationships and the relationship between segments of this chromosome and human chromosomes 8, 16, and 19.

  20. EST-derived SSR markers used as anchor loci for the construction of a consensus linkage map in ryegrass (Lolium spp.)

    DEFF Research Database (Denmark)

    Studer, Bruno; Kölliker, Roland; Muylle, Hilde;

    2010-01-01

    of publicly available Lolium EST-SSRs mapped for the first time together with previously mapped SSR markers will allow for consolidating existing mapping and QTL information in ryegrass. Map and markers presented here will prove to be an asset in the development for both molecular breeding of ryegrass as well......Background Genetic markers and linkage mapping are basic prerequisites for marker-assisted selection and map-based cloning. In the case of the key grassland species Lolium spp., numerous mapping populations have been developed and characterised for various traits. Although some genetic linkage maps...... of these populations have been aligned with each other using publicly available DNA markers, the number of common markers among genetic maps is still low, limiting the ability to compare candidate gene and QTL locations across germplasm. Results A set of 204 expressed sequence tag (EST)-derived simple sequence repeat...

  1. High-Density Genetic Map Construction and Gene Mapping of Basal Branching Habit and Flowers per Leaf Axil in Sesame

    Science.gov (United States)

    Mei, Hongxian; Liu, Yanyang; Du, Zhenwei; Wu, Ke; Cui, Chengqi; Jiang, Xiaolin; Zhang, Haiyang; Zheng, Yongzhan

    2017-01-01

    A good genetic map can provide the framework for quantitative trait loci (QTL) analysis, map-based gene cloning, and genome sequence assembling. The main objectives of this study were to develop a high-density genetic linkage map using specific length amplified fragment sequencing (SLAF-seq) in sesame. In the result, a high-resolution genetic map with 9,378 SLAF markers and 13 linkage groups (LGs) was constructed. The map spanned a total genetic distance of 1,974.23 cM, and the mean LG length was 151.86 cM, with an average genetic distance of 0.22 cM between adjacent markers. Based on the newly constructed genetic map, genes for basal branching habit (SiBH) and flowers per leaf axil (SiFA) were mapped to LG5 and LG11, respectively. PMID:28496450

  2. Mapping of panda plumage color locus on the microsatellite linkage map of the Japanese quail

    Directory of Open Access Journals (Sweden)

    Mizutani Makoto

    2006-01-01

    Full Text Available Abstract Background Panda (s is an autosomal recessive mutation, which displays overall white plumage color with spots of wild-type plumage in the Japanese quail (Coturnix japonica. In a previous study, the s locus was included in the same linkage group as serum albumin (Alb and vitamin-D binding protein (GC which are mapped on chicken (Gallus gallus chromosome 4 (GGA4. In this study, we mapped the s locus on the microsatellite linkage map of the Japanese quail by linkage analysis. Results Segregation data on the s locus were obtained from three-generation families (n = 106. Two microsatellite markers derived from the Japanese quail chromosome 4 (CJA04 and three microsatellite markers derived from GGA4 were genotyped in the three-generation families. We mapped the s locus between GUJ0026 and ABR0544 on CJA04. By comparative mapping with chicken, this locus was mapped between 10.0 Mb and 14.5 Mb region on GGA4. In this region, the endothelin receptor B subtype 2 gene (EDNRB2, an avian-specific paralog of the mammalian endothelin receptor B gene (EDNRB, is located. Because EDNRB is responsible for aganglionic megacolon and spot coat color in mouse, rat and equine, EDNRB2 is suggested to be a candidate gene for the s locus. Conclusion The s locus and the five microsatellite markers were mapped on CJA04 of the Japanese quail. EDNRB2 was suggested to be a candidate gene for the s locus.

  3. Development of SSR markers and construction of a linkage map in jute

    Indian Academy of Sciences (India)

    Maumita Das; Sumana Banerjee; Raman Dhariwal; Shailendra Vyas; Reyazul R. Mir; Niladri Topdar; Avijit Kundu; Jitendra P. Khurana; Akhilesh K. Tyagi; Debabrata Sarkar; Mohit K. Sinha; Harindra S. Balyan; Pushpendra K. Gupta

    2011-04-01

    Jute is an important natural fibre crop, which is only second to cotton in its importance at the global level. It is mostly grown in Indian subcontinent and has been recently used for the development of genomics resources.We recently initiated a programme to develop simple sequence repeat markers and reported a set of 2469 SSR that were developed using four SSR-enriched libraries (Mir et al. 2009). In this communication, we report an additional set of 607 novel SSR in 393 SSR containing sequences. However, primers could be designed for only 417 potentially useful SSR. Polymorphism survey was carried out for 374 primer pairs using two parental genotypes (JRO 524 and PPO4) of a mapping population developed for fibre fineness; only 66 SSR were polymorphic. Owing to a low level of polymorphism between the parental genotypes and a high degree of segregation distortion in recombinant inbred lines, genotypic data of only 53 polymorphic SSR on the mapping population consisting of 120 RIL could be used for the construction of a linkage map; 36 SSR loci were mapped on six linkage groups that covered a total genetic distance of 784.3 cM. Hopefully, this map will be enriched with more SSR loci in future and will prove useful for identification of quantitative trait loci/genes for molecular breeding involving improvement of fibre fineness and other related traits in jute.

  4. Development of SSR markers and construction of a linkage map in jute.

    Science.gov (United States)

    Das, Moumita; Banerjee, Sumana; Dhariwal, Raman; Vyas, Shailendra; Mir, Reyazul R; Topdar, Niladri; Kundu, Avijit; Khurana, Jitendra P; Tyagi, Akhilesh K; Sarkar, Debabrata; Sinha, Mohit K; Balyan, Harindra S; Gupta, Pushpendra K

    2012-01-01

    Jute is an important natural fibre crop, which is only second to cotton in its importance at the global level. It is mostly grown in Indian subcontinent and has been recently used for the development of genomics resources.We recently initiated a programme to develop simple sequence repeat markers and reported a set of 2469 SSR that were developed using four SSR-enriched libraries (Mir et al. 2009). In this communication, we report an additional set of 607 novel SSR in 393 SSR containing sequences. However, primers could be designed for only 417 potentially useful SSR. Polymorphism survey was carried out for 374 primer pairs using two parental genotypes (JRO 524 and PPO4) of a mapping population developed for fibre fineness; only 66 SSR were polymorphic. Owing to a low level of polymorphism between the parental genotypes and a high degree of segregation distortion in recombinant inbred lines, genotypic data of only 53 polymorphic SSR on the mapping population consisting of 120 RIL could be used for the construction of a linkage map; 36 SSR loci were mapped on six linkage groups that covered a total genetic distance of 784.3 cM. Hopefully, this map will be enriched with more SSR loci in future and will prove useful for identification of quantitative trait loci/genes for molecular breeding involving improvement of fibre fineness and other related traits in jute.

  5. Linkage mapping of putative regulator genes of barley grain development characterized by expression profiling

    Directory of Open Access Journals (Sweden)

    Wobus Ulrich

    2009-01-01

    Full Text Available Abstract Background Barley (Hordeum vulgare L. seed development is a highly regulated process with fine-tuned interaction of various tissues controlling distinct physiological events during prestorage, storage and dessication phase. As potential regulators involved within this process we studied 172 transcription factors and 204 kinases for their expression behaviour and anchored a subset of them to the barley linkage map to promote marker-assisted studies on barley grains. Results By a hierachical clustering of the expression profiles of 376 potential regulatory genes expressed in 37 different tissues, we found 50 regulators preferentially expressed in one of the three grain tissue fractions pericarp, endosperm and embryo during seed development. In addition, 27 regulators found to be expressed during both seed development and germination and 32 additional regulators are characteristically expressed in multiple tissues undergoing cell differentiation events during barley plant ontogeny. Another 96 regulators were, beside in the developing seed, ubiquitously expressed among all tissues of germinating seedlings as well as in reproductive tissues. SNP-marker development for those regulators resulted in anchoring 61 markers on the genetic linkage map of barley and the chromosomal assignment of another 12 loci by using wheat-barley addition lines. The SNP frequency ranged from 0.5 to 1.0 SNP/kb in the parents of the various mapping populations and was 2.3 SNP/kb over all eight lines tested. Exploration of macrosynteny to rice revealed that the chromosomal orders of the mapped putative regulatory factors were predominantly conserved during evolution. Conclusion We identified expression patterns of major transcription factors and signaling related genes expressed during barley ontogeny and further assigned possible functions based on likely orthologs functionally well characterized in model plant species. The combined linkage map and reference

  6. SNP-based linkage mapping for validation of QTLs for resistance to ascochyta blight in lentil

    Directory of Open Access Journals (Sweden)

    Shimna Sudheesh

    2016-11-01

    Full Text Available Lentil (Lens culinaris Medik. is a self-pollinating, diploid, annual, cool-season, food legume crop that is cultivated throughout the world. Ascochyta blight (AB, caused by Ascochyta lentis Vassilievsky, is an economically important and widespread disease of lentil. Development of cultivars with high levels of durable resistance provides an environmentally acceptable and economically feasible method for AB control. A detailed understanding of the genetic basis of AB resistance is hence highly desirable, in order to obtain insight into the number and influence of resistance genes. Genetic linkage maps based on single nucleotide polymorphisms (SNP and simple sequence repeat (SSR markers have been developed from three recombinant inbred line (RIL populations. The IH x NF map contained 460 loci across 1461.6 cM, while the IH x DIG map contained 329 loci across 1302.5 cM and the third map, NF x DIG contained 330 loci across 1914.1 cM. Data from these maps were combined with a map from a previously published study through use of bridging markers to generate a consensus linkage map containing 689 loci distributed across 7 linkage groups (LGs, with a cumulative length of 2429.61 cM at an average density of one marker per 3.5 cM. Trait dissection of AB resistance was performed for the RIL populations, identifying totals of two and three quantitative trait loci (QTLs explaining 52% and 69% of phenotypic variation for resistance to infection in the IH x DIG and IH x NF populations, respectively. Presence of common markers in the vicinity of the AB_IH1- and AB_IH2.1/AB_IH2.2-containing regions on both maps supports the inference that a common genomic region is responsible for conferring resistance and is associated with the resistant parent, Indianhead. The third QTL was derived from Northfield. Evaluation of markers associated with AB resistance across a diverse lentil germplasm panel revealed that the identity of alleles associated with AB_IH1 predicted

  7. EST-derived SSR markers used as anchor loci for the construction of a consensus linkage map in ryegrass (Lolium spp.

    Directory of Open Access Journals (Sweden)

    Studer Bruno

    2010-08-01

    Full Text Available Abstract Background Genetic markers and linkage mapping are basic prerequisites for marker-assisted selection and map-based cloning. In the case of the key grassland species Lolium spp., numerous mapping populations have been developed and characterised for various traits. Although some genetic linkage maps of these populations have been aligned with each other using publicly available DNA markers, the number of common markers among genetic maps is still low, limiting the ability to compare candidate gene and QTL locations across germplasm. Results A set of 204 expressed sequence tag (EST-derived simple sequence repeat (SSR markers has been assigned to map positions using eight different ryegrass mapping populations. Marker properties of a subset of 64 EST-SSRs were assessed in six to eight individuals of each mapping population and revealed 83% of the markers to be polymorphic in at least one population and an average number of alleles of 4.88. EST-SSR markers polymorphic in multiple populations served as anchor markers and allowed the construction of the first comprehensive consensus map for ryegrass. The integrated map was complemented with 97 SSRs from previously published linkage maps and finally contained 284 EST-derived and genomic SSR markers. The total map length was 742 centiMorgan (cM, ranging for individual chromosomes from 70 cM of linkage group (LG 6 to 171 cM of LG 2. Conclusions The consensus linkage map for ryegrass based on eight mapping populations and constructed using a large set of publicly available Lolium EST-SSRs mapped for the first time together with previously mapped SSR markers will allow for consolidating existing mapping and QTL information in ryegrass. Map and markers presented here will prove to be an asset in the development for both molecular breeding of ryegrass as well as comparative genetics and genomics within grass species.

  8. Genomewide Linkage Disequilibrium Mapping of Severe Bipolar Disorder in a Population Isolate

    Science.gov (United States)

    Ophoff, Roel A.; Escamilla, Michael A.; Service, Susan K.; Spesny, Mitzi; Meshi, Dar B.; Poon, Wingman; Molina, Julio; Fournier, Eduardo; Gallegos, Alvaro; Mathews, Carol; Neylan, Thomas; Batki, Steven L.; Roche, Erin; Ramirez, Margarita; Silva, Sandra; De Mille, Melissa C.; Dong, Penny; Leon, Pedro E.; Reus, Victor I.; Sandkuijl, Lodewijk A.; Freimer, Nelson B.

    2002-01-01

    Genomewide association studies may offer the best promise for genetic mapping of complex traits. Such studies in outbred populations require very densely spaced single-nucleotide polymorphisms. In recently founded population isolates, however, extensive linkage disequilibrium (LD) may make these studies feasible with currently available sets of short tandem repeat markers, spaced at intervals as large as a few centimorgans. We report the results of a genomewide association study of severe bipolar disorder (BP-I), using patients from the isolated population of the central valley of Costa Rica. We observed LD with BP-I on several chromosomes; the most striking results were in proximal 8p, a region that has previously shown linkage to schizophrenia. This region could be important for severe psychiatric disorders, rather than for a specific phenotype. PMID:12119601

  9. Genetic linkage heterogeneity in the fragile X syndrome.

    Science.gov (United States)

    Brown, W T; Gross, A C; Chan, C B; Jenkins, E C

    1985-01-01

    Genetic linkage between a factor IX DNA restriction fragment length polymorphism (RFLP) and the fragile X chromosome marker was analyzed in eight fragile X pedigrees and compared to eight previously reported pedigrees. A large pedigree with apparently full penetrance in all male members showed a high frequency of recombination. A lod score of -7.39 at theta = 0 and a maximum score of 0.26 at theta = 0.32 were calculated. A second large pedigree with a nonpenetrant male showed tight linkage with a maximum lod score of 3.13 at theta = 0, a result similar to one large pedigree with a nonpenetrant male previously reported. The differences in lod scores seen in these large pedigrees suggested there was genetic heterogeneity in linkage between families which appeared to relate to the presence of nonpenetrant males. The combined lod score for the three pedigrees with nonpenetrant males was 6.84 at theta = 0. For the 13 other pedigrees without nonpenetrant males the combined lod score was -21.81 at theta = 0, with a peak of 0.98 at theta = 0.28. When lod scores from all 16 families were combined, the value was -15.14 at theta = 0 and the overall maximum was 5.13 at theta = 0.17. To determine whether genetic heterogeneity was present, three statistical tests for heterogeneity were employed. First, a "predivided-sample" test was used. The 16 pedigrees were divided into two classes, NP and P, based upon whether or not any nonpenetrant males were detected in the pedigree. This test gave evidence for significant genetic heterogeneity whether the three large pedigrees with seven or more informative males (P less than 0.005), the eight pedigrees with three informative males (P less than 0.001), or all 16 pedigrees (P less than 0.001) were included in the analysis. Second, Morton's large sample test was employed. Significant heterogeneity was present when the analysis was restricted to the three large pedigrees (P less than 0.025), or to the eight pedigrees with informative males

  10. Linkage mapping of the locus for inherited ovine arthrogryposis (IOA) to sheep chromosome 5.

    Science.gov (United States)

    Murphy, Angela M; MacHugh, David E; Park, Stephen D E; Scraggs, Erik; Haley, Chris S; Lynn, David J; Boland, Maurice P; Doherty, Michael L

    2007-01-01

    Arthrogryposis is a congenital malformation affecting the limbs of newborn animals and infants. Previous work has demonstrated that inherited ovine arthrogryposis (IOA) has an autosomal recessive mode of inheritance. Two affected homozygous recessive (art/art) Suffolk rams were used as founders for a backcross pedigree of half-sib families segregating the IOA trait. A genome scan was performed using 187 microsatellite genetic markers and all backcross animals were phenotyped at birth for the presence and severity of arthrogryposis. Pairwise LOD scores of 1.86, 1.35, and 1.32 were detected for three microsatellites, BM741, JAZ, and RM006, that are located on sheep Chr 5 (OAR5). Additional markers in the region were identified from the genetic linkage map of BTA7 and by in silico analyses of the draft bovine genome sequence, three of which were informative. Interval mapping of all autosomes produced an F value of 21.97 (p < 0.01) for a causative locus in the region of OAR5 previously flagged by pairwise linkage analysis. Inspection of the orthologous region of HSA5 highlighted a previously fine-mapped locus for human arthrogryposis multiplex congenita neurogenic type (AMCN). A survey of the HSA5 genome sequence identified plausible candidate genes for both IOA and human AMCN.

  11. Linkage Map Construction and Quantitative Trait Locus Analysis of Agronomic and Fiber Quality Traits in Cotton

    Directory of Open Access Journals (Sweden)

    Michael A. Gore

    2014-03-01

    Full Text Available The superior fiber properties of L. serve as a source of novel variation for improving fiber quality in Upland cotton ( L., but introgression from has been largely unsuccessful due to hybrid breakdown and a lack of genetic and genomic resources. In an effort to overcome these limitations, we constructed a linkage map and conducted a quantitative trait locus (QTL analysis of 10 agronomic and fiber quality traits in a recombinant inbred mapping population derived from a cross between TM-1, an Upland cotton line, and NM24016, an elite line with stabilized introgression from . The linkage map consisted of 429 simple-sequence repeat (SSR and 412 genotyping-by-sequencing (GBS-based single-nucleotide polymorphism (SNP marker loci that covered half of the tetraploid cotton genome. Notably, the 841 marker loci were unevenly distributed among the 26 chromosomes of tetraploid cotton. The 10 traits evaluated on the TM-1 × NM24016 population in a multienvironment trial were highly heritable, and most of the fiber traits showed considerable transgressive variation. Through the QTL analysis, we identified a total of 28 QTLs associated with the 10 traits. Our study provides a novel resource that can be used by breeders and geneticists for the genetic improvement of agronomic and fiber quality traits in Upland cotton.

  12. An enhanced linkage map of the sheep genome comprising more than 1000 loci.

    Science.gov (United States)

    Maddox, J F; Davies, K P; Crawford, A M; Hulme, D J; Vaiman, D; Cribiu, E P; Freking, B A; Beh, K J; Cockett, N E; Kang, N; Riffkin, C D; Drinkwater, R; Moore, S S; Dodds, K G; Lumsden, J M; van Stijn, T C; Phua, S H; Adelson, D L; Burkin, H R; Broom, J E; Buitkamp, J; Cambridge, L; Cushwa, W T; Gerard, E; Galloway, S M; Harrison, B; Hawken, R J; Hiendleder, S; Henry, H M; Medrano, J F; Paterson, K A; Schibler, L; Stone, R T; van Hest, B

    2001-07-01

    A medium-density linkage map of the ovine genome has been developed. Marker data for 550 new loci were generated and merged with the previous sheep linkage map. The new map comprises 1093 markers representing 1062 unique loci (941 anonymous loci, 121 genes) and spans 3500 cM (sex-averaged) for the autosomes and 132 cM (female) on the X chromosome. There is an average spacing of 3.4 cM between autosomal loci and 8.3 cM between highly polymorphic [polymorphic information content (PIC) > or = 0.7] autosomal loci. The largest gap between markers is 32.5 cM, and the number of gaps of > 20 cM between loci, or regions where loci are missing from chromosome ends, has been reduced from 40 in the previous map to 6. Five hundred and seventy-three of the loci can be ordered on a framework map with odds of > 1000 : 1. The sheep linkage map contains strong links to both the cattle and goat maps. Five hundred and seventy-two of the loci positioned on the sheep linkage map have also been mapped by linkage analysis in cattle, and 209 of the loci mapped on the sheep linkage map have also been placed on the goat linkage map. Inspection of ruminant linkage maps indicates that the genomic coverage by the current sheep linkage map is comparable to that of the available cattle maps. The sheep map provides a valuable resource to the international sheep, cattle, and goat gene mapping community.

  13. High-density linkage mapping and evolution of paralogs and orthologs in Salix and Populus

    Directory of Open Access Journals (Sweden)

    Öst Torbjörn

    2010-02-01

    Full Text Available Abstract Background Salix (willow and Populus (poplar are members of the Salicaceae family and they share many ecological as well as genetic and genomic characteristics. The interest of using willow for biomass production is growing, which has resulted in increased pressure on breeding of high yielding and resistant clones adapted to different environments. The main purpose of this work was to develop dense genetic linkage maps for mapping of traits related to yield and resistance in willow. We used the Populus trichocarpa genome to extract evenly spaced markers and mapped the orthologous loci in the willow genome. The marker positions in the two genomes were used to study genome evolution since the divergence of the two lineages some 45 mya. Results We constructed two linkage maps covering the 19 linkage groups in willow. The most detailed consensus map, S1, contains 495 markers with a total genetic distance of 2477 cM and an average distance of 5.0 cM between the markers. The S3 consensus map contains 221 markers and has a total genetic distance of 1793 cM and an average distance of 8.1 cM between the markers. We found high degree of synteny and gene order conservation between willow and poplar. There is however evidence for two major interchromosomal rearrangements involving poplar LG I and XVI and willow LG Ib, suggesting a fission or a fusion in one of the lineages, as well as five intrachromosomal inversions. The number of silent substitutions were three times lower (median: 0.12 between orthologs than between paralogs (median: 0.37 - 0.41. Conclusions The relatively slow rates of genomic change between willow and poplar mean that the genomic resources in poplar will be most useful in genomic research in willow, such as identifying genes underlying QTLs of important traits. Our data suggest that the whole-genome duplication occurred long before the divergence of the two genera, events which have until now been regarded as contemporary

  14. High-resolution mapping of the gene for cystinosis, using combined biochemical and linkage analysis.

    Science.gov (United States)

    Jean, G; Fuchshuber, A; Town, M M; Gribouval, O; Schneider, J A; Broyer, M; van't Hoff, W; Niaudet, P; Antignac, C

    1996-03-01

    Infantile nephropathic cystinosis is an autosomal recessive disorder characterized biochemically by an abnormally high intracellular content of free cystine in different organs and tissues due to a transport defect of cystine through the lysosomal membrane. Affected children present with the Fanconi syndrome and usually develop progressive renal failure within the 1st decade of life. Measurement of free cystine in purified polymorphonuclear leukocytes provides an accurate method for diagnosis and detection of heterozygous carriers. In order to localize the gene locus for cystinosis we performed linkage analysis in 18 cystinosis families. However, since 17 of these were simplex families, we decided to include the phenotypes of the heterozygous carriers previously determined by their leukocyte cystine content in the linkage analysis. This approach allowed us to obtain highly significant results, confirming the localization of the cystinosis gene locus recently mapped to the short arm of chromosome 17 by the Cystinosis Collaborative Research Group. Crucial recombination events allowed us to refine the interval of the cystinosis gene to a genetic distance of 1 cM. No evidence of genetic heterogeneity was found. Our results demonstrate that the use of the previously determined phenotypes of heterozygous carriers in linkage analysis provides a reliable method for the investigation of simplex families in autosomal recessive traits.

  15. Genetic variation and linkage disequilibrium in Bacillus anthracis.

    Science.gov (United States)

    Zwick, Michael E; Thomason, Maureen Kiley; Chen, Peter E; Johnson, Henry R; Sozhamannan, Shanmuga; Mateczun, Alfred; Read, Timothy D

    2011-01-01

    We performed whole-genome amplification followed by hybridization of custom-designed resequencing arrays to resequence 303 kb of genomic sequence from a worldwide panel of 39 Bacillus anthracis strains. We used an efficient algorithm contained within a custom software program, UniqueMER, to identify and mask repetitive sequences on the resequencing array to reduce false-positive identification of genetic variation, which can arise from cross-hybridization. We discovered a total of 240 single nucleotide variants (SNVs) and showed that B. anthracis strains have an average of 2.25 differences per 10,000 bases in the region we resequenced. Common SNVs in this region are found to be in complete linkage disequilibrium. These patterns of variation suggest there has been little if any historical recombination among B. anthracis strains since the origin of the pathogen. This pattern of common genetic variation suggests a framework for recognizing new or genetically engineered strains.

  16. Construction of an integrated high density simple sequence repeat linkage map in cultivated strawberry (Fragaria × ananassa) and its applicability.

    Science.gov (United States)

    Isobe, Sachiko N; Hirakawa, Hideki; Sato, Shusei; Maeda, Fumi; Ishikawa, Masami; Mori, Toshiki; Yamamoto, Yuko; Shirasawa, Kenta; Kimura, Mitsuhiro; Fukami, Masanobu; Hashizume, Fujio; Tsuji, Tomoko; Sasamoto, Shigemi; Kato, Midori; Nanri, Keiko; Tsuruoka, Hisano; Minami, Chiharu; Takahashi, Chika; Wada, Tsuyuko; Ono, Akiko; Kawashima, Kumiko; Nakazaki, Naomi; Kishida, Yoshie; Kohara, Mitsuyo; Nakayama, Shinobu; Yamada, Manabu; Fujishiro, Tsunakazu; Watanabe, Akiko; Tabata, Satoshi

    2013-02-01

    The cultivated strawberry (Fragaria × ananassa) is an octoploid (2n = 8x = 56) of the Rosaceae family whose genomic architecture is still controversial. Several recent studies support the AAA'A'BBB'B' model, but its complexity has hindered genetic and genomic analysis of this important crop. To overcome this difficulty and to assist genome-wide analysis of F. × ananassa, we constructed an integrated linkage map by organizing a total of 4474 of simple sequence repeat (SSR) markers collected from published Fragaria sequences, including 3746 SSR markers [Fragaria vesca expressed sequence tag (EST)-derived SSR markers] derived from F. vesca ESTs, 603 markers (F. × ananassa EST-derived SSR markers) from F. × ananassa ESTs, and 125 markers (F. × ananassa transcriptome-derived SSR markers) from F. × ananassa transcripts. Along with the previously published SSR markers, these markers were mapped onto five parent-specific linkage maps derived from three mapping populations, which were then assembled into an integrated linkage map. The constructed map consists of 1856 loci in 28 linkage groups (LGs) that total 2364.1 cM in length. Macrosynteny at the chromosome level was observed between the LGs of F. × ananassa and the genome of F. vesca. Variety distinction on 129 F. × ananassa lines was demonstrated using 45 selected SSR markers.

  17. Prioritizing tiger conservation through landscape genetics and habitat linkages.

    Science.gov (United States)

    Yumnam, Bibek; Jhala, Yadvendradev V; Qureshi, Qamar; Maldonado, Jesus E; Gopal, Rajesh; Saini, Swati; Srinivas, Y; Fleischer, Robert C

    2014-01-01

    Even with global support for tiger (Panthera tigris) conservation their survival is threatened by poaching, habitat loss and isolation. Currently about 3,000 wild tigers persist in small fragmented populations within seven percent of their historic range. Identifying and securing habitat linkages that connect source populations for maintaining landscape-level gene flow is an important long-term conservation strategy for endangered carnivores. However, habitat corridors that link regional tiger populations are often lost to development projects due to lack of objective evidence on their importance. Here, we use individual based genetic analysis in combination with landscape permeability models to identify and prioritize movement corridors across seven tiger populations within the Central Indian Landscape. By using a panel of 11 microsatellites we identified 169 individual tigers from 587 scat and 17 tissue samples. We detected four genetic clusters within Central India with limited gene flow among three of them. Bayesian and likelihood analyses identified 17 tigers as having recent immigrant ancestry. Spatially explicit tiger occupancy obtained from extensive landscape-scale surveys across 76,913 km(2) of forest habitat was found to be only 21,290 km(2). After accounting for detection bias, the covariates that best explained tiger occupancy were large, remote, dense forest patches; large ungulate abundance, and low human footprint. We used tiger occupancy probability to parameterize habitat permeability for modeling habitat linkages using least-cost and circuit theory pathway analyses. Pairwise genetic differences (FST) between populations were better explained by modeled linkage costs (r>0.5, p<0.05) compared to Euclidean distances, which was in consonance with observed habitat fragmentation. The results of our study highlight that many corridors may still be functional as there is evidence of contemporary migration. Conservation efforts should provide legal status

  18. Prioritizing tiger conservation through landscape genetics and habitat linkages.

    Directory of Open Access Journals (Sweden)

    Bibek Yumnam

    Full Text Available Even with global support for tiger (Panthera tigris conservation their survival is threatened by poaching, habitat loss and isolation. Currently about 3,000 wild tigers persist in small fragmented populations within seven percent of their historic range. Identifying and securing habitat linkages that connect source populations for maintaining landscape-level gene flow is an important long-term conservation strategy for endangered carnivores. However, habitat corridors that link regional tiger populations are often lost to development projects due to lack of objective evidence on their importance. Here, we use individual based genetic analysis in combination with landscape permeability models to identify and prioritize movement corridors across seven tiger populations within the Central Indian Landscape. By using a panel of 11 microsatellites we identified 169 individual tigers from 587 scat and 17 tissue samples. We detected four genetic clusters within Central India with limited gene flow among three of them. Bayesian and likelihood analyses identified 17 tigers as having recent immigrant ancestry. Spatially explicit tiger occupancy obtained from extensive landscape-scale surveys across 76,913 km(2 of forest habitat was found to be only 21,290 km(2. After accounting for detection bias, the covariates that best explained tiger occupancy were large, remote, dense forest patches; large ungulate abundance, and low human footprint. We used tiger occupancy probability to parameterize habitat permeability for modeling habitat linkages using least-cost and circuit theory pathway analyses. Pairwise genetic differences (FST between populations were better explained by modeled linkage costs (r>0.5, p<0.05 compared to Euclidean distances, which was in consonance with observed habitat fragmentation. The results of our study highlight that many corridors may still be functional as there is evidence of contemporary migration. Conservation efforts should

  19. Linkage disequilibrium based association mapping of fiber quality traits in G. hirsutum L. variety germplasm.

    Science.gov (United States)

    Abdurakhmonov, Ibrokhim Y; Saha, Sukumar; Jenkins, Jonnie N; Buriev, Zabardast T; Shermatov, Shukhrat E; Scheffler, Brain E; Pepper, Alan E; Yu, John Z; Kohel, Russell J; Abdukarimov, Abdusattor

    2009-07-01

    Cotton is the world's leading cash crop, but it lags behind other major crops for marker-assisted breeding due to limited polymorphisms and a genetic bottleneck through historic domestication. This underlies a need for characterization, tagging, and utilization of existing natural polymorphisms in cotton germplasm collections. Here we report genetic diversity, population characteristics, the extent of linkage disequilibrium (LD), and association mapping of fiber quality traits using 202 microsatellite marker primer pairs in 335 G. hirsutum germplasm grown in two diverse environments, Uzbekistan and Mexico. At the significance threshold (r (2) >or= 0.1), a genome-wide average of LD extended up to genetic distance of 25 cM in assayed cotton variety accessions. Genome wide LD at r (2) >or= 0.2 was reduced to approximately 5-6 cM, providing evidence of the potential for association mapping of agronomically important traits in cotton. Results suggest linkage, selection, inbreeding, population stratification, and genetic drift as the potential LD-generating factors in cotton. In two environments, an average of ~20 SSR markers was associated with each main fiber quality traits using a unified mixed liner model (MLM) incorporating population structure and kinship. These MLM-derived significant associations were confirmed in general linear model and structured association test, accounting for population structure and permutation-based multiple testing. Several common markers, showing the significant associations in both Uzbekistan and Mexican environments, were determined. Between 7 and 43% of the MLM-derived significant associations were supported by a minimum Bayes factor at 'moderate to strong' and 'strong to very strong' evidence levels, suggesting their usefulness for marker-assisted breeding programs and overall effectiveness of association mapping using cotton germplasm resources.

  20. A microsatellite marker linkage map of the housefly, Musca domestica : Evidence for male recombination

    NARCIS (Netherlands)

    Feldmeyer, B.; Pen, I.; Beukeboom, L. W.

    2010-01-01

    We present the first molecular marker linkage map for Musca domestica containing 35 microsatellite plus six visible markers. We report the development of 33 new microsatellite markers of which 19 are included in the linkage map. Two hundred and thirty-six F2 individuals were genotyped from three cro

  1. The Double-Reduction Landscape in Tetraploid Potato as Revealed by a High-Density Linkage Map.

    Science.gov (United States)

    Bourke, Peter M; Voorrips, Roeland E; Visser, Richard G F; Maliepaard, Chris

    2015-11-01

    The creation of genetic linkage maps in polyploid species has been a long-standing problem for which various approaches have been proposed. In the case of autopolyploids, a commonly used simplification is that random bivalents form during meiosis. This leads to relatively straightforward estimation of recombination frequencies using maximum likelihood, from which a genetic map can be derived. However, autopolyploids such as tetraploid potato (Solanum tuberosum L.) may exhibit additional features, such as double reduction, not normally encountered in diploid or allopolyploid species. In this study, we produced a high-density linkage map of tetraploid potato and used it to identify regions of double reduction in a biparental mapping population. The frequency of multivalents required to produce this degree of double reduction was determined through simulation. We also determined the effect that multivalents or preferential pairing between homologous chromosomes has on linkage mapping. Low levels of multivalents or preferential pairing do not adversely affect map construction when highly informative marker types and phases are used. We reveal the double-reduction landscape in tetraploid potato, clearly showing that this phenomenon increases with distance from the centromeres.

  2. Construction of Soybean Genetic Map with RIL Population by Charleston ×Dongnong 594

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    F2:10 RIL population with 154 lines, crossed by Charleston as female parent and Dongnong 594 as male parent were used.164 SSR primers were screened with the two parents and amplified on the 154 lines. A new soybean molecular genetics map, named NEAUSRI-GMS, was constructed by Mapmaker. The total length of the soybean genetic map is 1 913.5 cM,and the average distance among markers is 11.89 cM. The length of linkage group varied from 0.4 to 309.5 cM, and the markers on the linkage group varied from 2 to 28. The distribution of SSR markers on every linkage group is not even. High density region of markers existed on linkage group Al, C2, and Dla. Compared with 5 soybean genetic maps constructed at home and abroad, NEAUSRI-GMS has high homologous with the public genetic map abroad.

  3. Natural Allelic Diversity, Genetic Structure and Linkage Disequilibrium Pattern in Wild Chickpea

    Science.gov (United States)

    Kujur, Alice; Das, Shouvik; Badoni, Saurabh; Kumar, Vinod; Singh, Mohar; Bansal, Kailash C.; Tyagi, Akhilesh K.; Parida, Swarup K.

    2014-01-01

    Characterization of natural allelic diversity and understanding the genetic structure and linkage disequilibrium (LD) pattern in wild germplasm accessions by large-scale genotyping of informative microsatellite and single nucleotide polymorphism (SNP) markers is requisite to facilitate chickpea genetic improvement. Large-scale validation and high-throughput genotyping of genome-wide physically mapped 478 genic and genomic microsatellite markers and 380 transcription factor gene-derived SNP markers using gel-based assay, fluorescent dye-labelled automated fragment analyser and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass array have been performed. Outcome revealed their high genotyping success rate (97.5%) and existence of a high level of natural allelic diversity among 94 wild and cultivated Cicer accessions. High intra- and inter-specific polymorphic potential and wider molecular diversity (11–94%) along with a broader genetic base (13–78%) specifically in the functional genic regions of wild accessions was assayed by mapped markers. It suggested their utility in monitoring introgression and transferring target trait-specific genomic (gene) regions from wild to cultivated gene pool for the genetic enhancement. Distinct species/gene pool-wise differentiation, admixed domestication pattern, and differential genome-wide recombination and LD estimates/decay observed in a six structured population of wild and cultivated accessions using mapped markers further signifies their usefulness in chickpea genetics, genomics and breeding. PMID:25222488

  4. Linkage mapping in tetraploid willows: segregation of molecular markers and estimation of linkage phases support an allotetraploid structure for Salix alba x Salix fragilis interspecific hybrids.

    Science.gov (United States)

    Barcaccia, G; Meneghetti, S; Albertini, E; Triest, L; Lucchin, M

    2003-02-01

    Salix alba-Salix fragilis complex includes closely related dioecious polyploid species, which are obligate outcrossers. Natural populations of these willows and their hybrids are represented by a mixture of highly heterozygous genotypes sharing a common gene pool. Since nothing is known about their genomic constitution, tetraploidy (2n=4x=76) in willow species makes basic and applied genetic studies difficult. We have used a two-way pseudotestcross strategy and single-dose markers (SDMs) to construct the first linkage maps for both pistillate and staminate willows. A total of 242 amplified fragment length polymorphisms (AFLPs) and 50 selective amplifications of microsatellite polymorphic loci (SAMPL) markers, which showed 1:1 segregation in the F(1) mapping populations, were used in linkage analysis. In S. alba, 73 maternal and 48 paternal SDMs were mapped to 19 and 16 linkage groups covering 708 and 339 cM, respectively. In S. fragilis, 13 maternal and 33 paternal SDMs were mapped in six and 14 linkage groups covering 98 and 321 cM, respectively. For most cosegregation groups, a comparable number of markers linked in coupling and repulsion was identified. This finding suggests that most of chromosomes pair preferentially as occurs in allotetraploid species exhibiting disomic inheritance. The detection of 10 pairs of marker alleles from single parents showing codominant inheritance strengthens this hypothesis. The fact that, of the 1122 marker loci identified in the two male and female parents, the vast majority (77.5%) were polymorphic and as few as 22.5% were shared between parental species highlight that S. alba and S. fragilis genotypes are differentiated. The highly difference between S. alba- and S. fragilis-specific markers found in both parental combinations (on average, 65.3 vs 34.7%, respectively) supports the (phylogenetic) hypothesis that S. fragilis is derived from S. alba-like progenitors.

  5. Evolutionary origins and dynamics of octoploid strawberry subgenomes revealed by dense targeted capture linkage maps.

    Science.gov (United States)

    Tennessen, Jacob A; Govindarajulu, Rajanikanth; Ashman, Tia-Lynn; Liston, Aaron

    2014-12-04

    Whole-genome duplications are radical evolutionary events that have driven speciation and adaptation in many taxa. Higher-order polyploids have complex histories often including interspecific hybridization and dynamic genomic changes. This chromosomal reshuffling is poorly understood for most polyploid species, despite their evolutionary and agricultural importance, due to the challenge of distinguishing homologous sequences from each other. Here, we use dense linkage maps generated with targeted sequence capture to improve the diploid strawberry (Fragaria vesca) reference genome and to disentangle the subgenomes of the wild octoploid progenitors of cultivated strawberry, Fragaria virginiana and Fragaria chiloensis. Our novel approach, POLiMAPS (Phylogenetics Of Linkage-Map-Anchored Polyploid Subgenomes), leverages sequence reads to associate informative interhomeolog phylogenetic markers with linkage groups and reference genome positions. In contrast to a widely accepted model, we find that one of the four subgenomes originates with the diploid cytoplasm donor F. vesca, one with the diploid Fragaria iinumae, and two with an unknown ancestor close to F. iinumae. Extensive unidirectional introgression has converted F. iinumae-like subgenomes to be more F. vesca-like, but never the reverse, due either to homoploid hybridization in the F. iinumae-like diploid ancestors or else strong selection spreading F. vesca-like sequence among subgenomes through homeologous exchange. In addition, divergence between homeologous chromosomes has been substantially augmented by interchromosomal rearrangements. Our phylogenetic approach reveals novel aspects of the complicated web of genetic exchanges that occur during polyploid evolution and suggests a path forward for unraveling other agriculturally and ecologically important polyploid genomes.

  6. Genome-wide linkage meta-analysis identifies susceptibility loci at 2q34 and 13q31.3 for genetic generalized epilepsies

    DEFF Research Database (Denmark)

    Leu, Costin; de Kovel, Carolien G F; Zara, Federico

    2012-01-01

    Purpose: Genetic generalized epilepsies (GGEs) have a lifetime prevalence of 0.3% with heritability estimates of 80%. A considerable proportion of families with siblings affected by GGEs presumably display an oligogenic inheritance. The present genome-wide linkage meta-analysis aimed to map: (1...... ancestry including 982 relatives with GGEs. To dissect out seizure type-related susceptibility genes, two family subgroups were stratified comprising 235 families with predominantly genetic absence epilepsies (GAEs) and 118 families with an aggregation of juvenile myoclonic epilepsy (JME). To map shared...... Findings: For the entire set of 379 GGE-multiplex families, linkage analysis revealed six loci achieving suggestive evidence for linkage at 1p36.22, 3p14.2, 5q34, 13q12.12, 13q31.3, and 19q13.42. The linkage finding at 5q34 was consistently supported by both NPL and parametric linkage results across all...

  7. High-throughput SNP discovery and genotyping for constructing a saturated linkage map of chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Gaur, Rashmi; Azam, Sarwar; Jeena, Ganga; Khan, Aamir Waseem; Choudhary, Shalu; Jain, Mukesh; Yadav, Gitanjali; Tyagi, Akhilesh K; Chattopadhyay, Debasis; Bhatia, Sabhyata

    2012-10-01

    The present study reports the large-scale discovery of genome-wide single-nucleotide polymorphisms (SNPs) in chickpea, identified mainly through the next generation sequencing of two genotypes, i.e. Cicer arietinum ICC4958 and its wild progenitor C. reticulatum PI489777, parents of an inter-specific reference mapping population of chickpea. Development and validation of a high-throughput SNP genotyping assay based on Illumina's GoldenGate Genotyping Technology and its application in building a high-resolution genetic linkage map of chickpea is described for the first time. In this study, 1022 SNPs were identified, of which 768 high-confidence SNPs were selected for designing the custom Oligo Pool All (CpOPA-I) for genotyping. Of these, 697 SNPs could be successfully used for genotyping, demonstrating a high success rate of 90.75%. Genotyping data of the 697 SNPs were compiled along with those of 368 co-dominant markers mapped in an earlier study, and a saturated genetic linkage map of chickpea was constructed. One thousand and sixty-three markers were mapped onto eight linkage groups spanning 1808.7 cM (centiMorgans) with an average inter-marker distance of 1.70 cM, thereby representing one of the most advanced maps of chickpea. The map was used for the synteny analysis of chickpea, which revealed a higher degree of synteny with the phylogenetically close Medicago than with soybean. The first set of validated SNPs and map resources developed in this study will not only facilitate QTL mapping, genome-wide association analysis and comparative mapping in legumes but also help anchor scaffolds arising out of the whole-genome sequencing of chickpea.

  8. Ultrahigh-density linkage map for cultivated cucumber (Cucumis sativus L. using a single-nucleotide polymorphism genotyping array.

    Directory of Open Access Journals (Sweden)

    Mor Rubinstein

    Full Text Available Genotyping arrays are tools for high-throughput genotyping, which is beneficial in constructing saturated genetic maps and therefore high-resolution mapping of complex traits. Since the report of the first cucumber genome draft, genetic maps have been constructed mainly based on simple-sequence repeats (SSRs or on combinations of SSRs and sequence-related amplified polymorphism (SRAP. In this study, we developed the first cucumber genotyping array consisting of 32,864 single-nucleotide polymorphisms (SNPs. These markers cover the cucumber genome with a median interval of ~2 Kb and have expected genotype calls in parents/F1 hybridizations as a training set. The training set was validated with Fluidigm technology and showed 96% concordance with the genotype calls in the parents/F1 hybridizations. Application of the genotyping array was illustrated by constructing a 598.7 cM genetic map based on a '9930' × 'Gy14' recombinant inbred line (RIL population comprised of 11,156 SNPs. Marker collinearity between the genetic map and reference genomes of the two parents was estimated at R2 = 0.97. We also used the array-derived genetic map to investigate chromosomal rearrangements, regional recombination rate, and specific regions with segregation distortions. Finally, 82% of the linkage-map bins were polymorphic in other cucumber variants, suggesting that the array can be applied for genotyping in other lines. The genotyping array presented here, together with the genotype calls of the parents/F1 hybridizations as a training set, should be a powerful tool in future studies with high-throughput cucumber genotyping. An ultrahigh-density linkage map constructed by this genotyping array on RIL population may be invaluable for assembly improvement, and for mapping important cucumber QTLs.

  9. Molecular characterization of Blau syndrome: Genetic linkage to chromosome 16

    Energy Technology Data Exchange (ETDEWEB)

    Tromp, G.; Duivaniemi, H.; Christiano, A. [Thomas Jefferson Univ., Philadelphia, PA (United States)] [and others

    1994-09-01

    The Blau syndrome is an autosomal, dominantly-inherited disease characterized by multi-organ, tissue-specific inflammation. Its clinical phenotype includes granulomatous uveitis, arthritis and skin rash. The syndrome is unique in that it is the sole human model for a variety of multi-system inflammatory diseases that afflict a significant percentage of the population. Karyotypic analysis of the large, three generation kindred whose disease originally characterized the syndrome was unremarkable. Following exclusion of a number of extracellular matrix candidates genes, a genome-wide search was undertaken of the Blau susceptibility locus. Fifty-seven members of the family were genotyped for about 200 highly polymorphic dinucleotide repeat markers. Linkage analysis was performed using the LINKAGE package of programs under a model of dominant inheritance with reduced penetrance. Five liability classes were used to specify penetrances and phenocopy rates for those affected the arthritis, uveitis, skin rash and combinations thererof. In addition, five age-dependent penetrance classes were used for unaffected individuals. The marker D16S298 gave a maximum lod score of 3.6 at {theta} = 0.05 with two-point analysis. Lod scores for flanking markers were consistent. These data provide convincing evidence that the Blau susceptibility locus is situated within the 16p12-q21 interval. Fine mapping of the candidate interval with additional families exhibiting the Blau phenotype, as well as with more polymorphic markers, is underway.

  10. Construction and comparative analyses of highly dense linkage maps of two sweet cherry intra-specific progenies of commercial cultivars.

    Directory of Open Access Journals (Sweden)

    Carolina Klagges

    Full Text Available Despite the agronomical importance and high synteny with other Prunus species, breeding improvements for cherry have been slow compared to other temperate fruits, such as apple or peach. However, the recent release of the peach genome v1.0 by the International Peach Genome Initiative and the sequencing of cherry accessions to identify Single Nucleotide Polymorphisms (SNPs provide an excellent basis for the advancement of cherry genetic and genomic studies. The availability of dense genetic linkage maps in phenotyped segregating progenies would be a valuable tool for breeders and geneticists. Using two sweet cherry (Prunus avium L. intra-specific progenies derived from crosses between 'Black Tartarian' × 'Kordia' (BT×K and 'Regina' × 'Lapins'(R×L, high-density genetic maps of the four parental lines and the two segregating populations were constructed. For BT×K and R×L, 89 and 121 F(1 plants were used for linkage mapping, respectively. A total of 5,696 SNP markers were tested in each progeny. As a result of these analyses, 723 and 687 markers were mapped into eight linkage groups (LGs in BT×K and R×L, respectively. The resulting maps spanned 752.9 and 639.9 cM with an average distance of 1.1 and 0.9 cM between adjacent markers in BT×K and R×L, respectively. The maps displayed high synteny and co-linearity between each other, with the Prunus bin map, and with the peach genome v1.0 for all eight LGs (LG1-LG8. These maps provide a useful tool for investigating traits of interest in sweet cherry and represent a qualitative advance in the understanding of the cherry genome and its synteny with other members of the Rosaceae family.

  11. Construction and Comparative Analyses of Highly Dense Linkage Maps of Two Sweet Cherry Intra-Specific Progenies of Commercial Cultivars

    Science.gov (United States)

    Quero-García, José; Guzmán, Alejandra; Mansur, Levi; Gratacós, Eduardo; Silva, Herman; Rosyara, Umesh R.; Iezzoni, Amy; Meisel, Lee A.; Dirlewanger, Elisabeth

    2013-01-01

    Despite the agronomical importance and high synteny with other Prunus species, breeding improvements for cherry have been slow compared to other temperate fruits, such as apple or peach. However, the recent release of the peach genome v1.0 by the International Peach Genome Initiative and the sequencing of cherry accessions to identify Single Nucleotide Polymorphisms (SNPs) provide an excellent basis for the advancement of cherry genetic and genomic studies. The availability of dense genetic linkage maps in phenotyped segregating progenies would be a valuable tool for breeders and geneticists. Using two sweet cherry (Prunus avium L.) intra-specific progenies derived from crosses between ‘Black Tartarian’ × ‘Kordia’ (BT×K) and ‘Regina’ × ‘Lapins’(R×L), high-density genetic maps of the four parental lines and the two segregating populations were constructed. For BT×K and R×L, 89 and 121 F1 plants were used for linkage mapping, respectively. A total of 5,696 SNP markers were tested in each progeny. As a result of these analyses, 723 and 687 markers were mapped into eight linkage groups (LGs) in BT×K and R×L, respectively. The resulting maps spanned 752.9 and 639.9 cM with an average distance of 1.1 and 0.9 cM between adjacent markers in BT×K and R×L, respectively. The maps displayed high synteny and co-linearity between each other, with the Prunus bin map, and with the peach genome v1.0 for all eight LGs (LG1–LG8). These maps provide a useful tool for investigating traits of interest in sweet cherry and represent a qualitative advance in the understanding of the cherry genome and its synteny with other members of the Rosaceae family. PMID:23382953

  12. Linkage mapping and comparative genomics using next-generation RAD sequencing of a non-model organism.

    Directory of Open Access Journals (Sweden)

    Simon W Baxter

    Full Text Available Restriction-site associated DNA (RAD sequencing is a powerful new method for targeted sequencing across the genomes of many individuals. This approach has broad potential for genetic analysis of non-model organisms including genotype-phenotype association mapping, phylogeography, population genetics and scaffolding genome assemblies through linkage mapping. We constructed a RAD library using genomic DNA from a Plutella xylostella (diamondback moth backcross that segregated for resistance to the insecticide spinosad. Sequencing of 24 individuals was performed on a single Illumina GAIIx lane (51 base paired-end reads. Taking advantage of the lack of crossing over in homologous chromosomes in female Lepidoptera, 3,177 maternally inherited RAD alleles were assigned to the 31 chromosomes, enabling identification of the spinosad resistance and W/Z sex chromosomes. Paired-end reads for each RAD allele were assembled into contigs and compared to the genome of Bombyx mori (n = 28 using BLAST, revealing 28 homologous matches plus 3 expected fusion/breakage events which account for the difference in chromosome number. A genome-wide linkage map (1292 cM was inferred with 2,878 segregating RAD alleles inherited from the backcross father, producing chromosome and location specific sequenced RAD markers. Here we have used RAD sequencing to construct a genetic linkage map de novo for an organism that has no previous genome data. Comparative analysis of P. xyloxtella linkage groups with B. mori chromosomes shows for the first time, genetic synteny appears common beyond the Macrolepidoptera. RAD sequencing is a powerful system capable of rapidly generating chromosome specific data for non-model organisms.

  13. Construction of a High-Density Genetic Map and Quantitative Trait Locus Mapping in the Sea Cucumber Apostichopus japonicus.

    Science.gov (United States)

    Tian, Meilin; Li, Yangping; Jing, Jing; Mu, Chuang; Du, Huixia; Dou, Jinzhuang; Mao, Junxia; Li, Xue; Jiao, Wenqian; Wang, Yangfan; Hu, Xiaoli; Wang, Shi; Wang, Ruijia; Bao, Zhenmin

    2015-10-06

    Genetic linkage maps are critical and indispensable tools in a wide range of genetic and genomic research. With the advancement of genotyping-by-sequencing (GBS) methods, the construction of a high-density and high-resolution linkage maps has become achievable in marine organisms lacking sufficient genomic resources, such as echinoderms. In this study, high-density, high-resolution genetic map was constructed for a sea cucumber species, Apostichopus japonicus, utilizing the 2b-restriction site-associated DNA (2b-RAD) method. A total of 7839 markers were anchored to the linkage map with the map coverage of 99.57%, to our knowledge, this is the highest marker density among echinoderm species. QTL mapping and association analysis consistently captured one growth-related QTL located in a 5 cM region of linkage group (LG) 5. An annotated candidate gene, retinoblastoma-binding protein 5 (RbBP5), which has been reported to be an important regulator of cell proliferation, was recognized in the QTL region. This linkage map represents a powerful tool for research involving both fine-scale QTL mapping and marker assisted selection (MAS), and will facilitate chromosome assignment and improve the whole-genome assembly of sea cucumber in the future.

  14. An autotetraploid linkage map of rose (Rosa hybrida) validated using the strawberry (Fragaria vesca) genome sequence.

    Science.gov (United States)

    Gar, Oron; Sargent, Daniel J; Tsai, Ching-Jung; Pleban, Tzili; Shalev, Gil; Byrne, David H; Zamir, Dani

    2011-01-01

    Polyploidy is a pivotal process in plant evolution as it increase gene redundancy and morphological intricacy but due to the complexity of polysomic inheritance we have only few genetic maps of autopolyploid organisms. A robust mapping framework is particularly important in polyploid crop species, rose included (2n = 4x = 28), where the objective is to study multiallelic interactions that control traits of value for plant breeding. From a cross between the garden, peach red and fragrant cultivar Fragrant Cloud (FC) and a cut-rose yellow cultivar Golden Gate (GG), we generated an autotetraploid GGFC mapping population consisting of 132 individuals. For the map we used 128 sequence-based markers, 141 AFLP, 86 SSR and three morphological markers. Seven linkage groups were resolved for FC (Total 632 cM) and GG (616 cM) which were validated by markers that segregated in both parents as well as the diploid integrated consensus map.The release of the Fragaria vesca genome, which also belongs to the Rosoideae, allowed us to place 70 rose sequenced markers on the seven strawberry pseudo-chromosomes. Synteny between Rosa and Fragaria was high with an estimated four major translocations and six inversions required to place the 17 non-collinear markers in the same order. Based on a verified linear order of the rose markers, we could further partition each of the parents into its four homologous groups, thus providing an essential framework to aid the sequencing of an autotetraploid genome.

  15. Genome-wide distribution of genetic diversity and linkage disequilibrium in elite sugar beet germplasm

    Directory of Open Access Journals (Sweden)

    Weißleder Knuth

    2011-10-01

    Full Text Available Abstract Background Characterization of population structure and genetic diversity of germplasm is essential for the efficient organization and utilization of breeding material. The objectives of this study were to (i explore the patterns of population structure in the pollen parent heterotic pool using different methods, (ii investigate the genome-wide distribution of genetic diversity, and (iii assess the extent and genome-wide distribution of linkage disequilibrium (LD in elite sugar beet germplasm. Results A total of 264 and 238 inbred lines from the yield type and sugar type inbreds of the pollen parent heterotic gene pools, respectively, which had been genotyped with 328 SNP markers, were used in this study. Two distinct subgroups were detected based on different statistical methods within the elite sugar beet germplasm set, which was in accordance with its breeding history. MCLUST based on principal components, principal coordinates, or lapvectors had high correspondence with the germplasm type information as well as the assignment by STRUCTURE, which indicated that these methods might be alternatives to STRUCTURE for population structure analysis. Gene diversity and modified Roger's distance between the examined germplasm types varied considerably across the genome, which might be due to artificial selection. This observation indicates that population genetic approaches could be used to identify candidate genes for the traits under selection. Due to the fact that r2 >0.8 is required to detect marker-phenotype association explaining less than 1% of the phenotypic variance, our observation of a low proportion of SNP loci pairs showing such levels of LD suggests that the number of markers has to be dramatically increased for powerful genome-wide association mapping. Conclusions We provided a genome-wide distribution map of genetic diversity and linkage disequilibrium for the elite sugar beet germplasm, which is useful for the application of

  16. High density linkage mapping of genomic and transcriptomic SNPs for synteny analysis and anchoring the genome sequence of chickpea

    Science.gov (United States)

    Gaur, Rashmi; Jeena, Ganga; Shah, Niraj; Gupta, Shefali; Pradhan, Seema; Tyagi, Akhilesh K; Jain, Mukesh; Chattopadhyay, Debasis; Bhatia, Sabhyata

    2015-01-01

    This study presents genome-wide discovery of SNPs through next generation sequencing of the genome of Cicer reticulatum. Mapping of the C. reticulatum sequenced reads onto the draft genome assembly of C. arietinum (desi chickpea) resulted in identification of 842,104 genomic SNPs which were utilized along with an additional 36,446 genic SNPs identified from transcriptome sequences of the aforementioned varieties. Two new chickpea Oligo Pool All (OPAs) each having 3,072 SNPs were designed and utilized for SNP genotyping of 129 Recombinant Inbred Lines (RILs). Using Illumina GoldenGate Technology genotyping data of 5,041 SNPs were generated and combined with the 1,673 marker data from previously published studies, to generate a high resolution linkage map. The map comprised of 6698 markers distributed on eight linkage groups spanning 1083.93 cM with an average inter-marker distance of 0.16 cM. Utility of the present map was demonstrated for improving the anchoring of the earlier reported draft genome sequence of desi chickpea by ~30% and that of kabuli chickpea by 18%. The genetic map reported in this study represents the most dense linkage map of chickpea , with the potential to facilitate efficient anchoring of the draft genome sequences of desi as well as kabuli chickpea varieties. PMID:26303721

  17. Construction of High Density Sweet Cherry (Prunus avium L.) Linkage Maps Using Microsatellite Markers and SNPs Detected by Genotyping-by-Sequencing (GBS).

    Science.gov (United States)

    Guajardo, Verónica; Solís, Simón; Sagredo, Boris; Gainza, Felipe; Muñoz, Carlos; Gasic, Ksenija; Hinrichsen, Patricio

    2015-01-01

    Linkage maps are valuable tools in genetic and genomic studies. For sweet cherry, linkage maps have been constructed using mainly microsatellite markers (SSRs) and, recently, using single nucleotide polymorphism markers (SNPs) from a cherry 6K SNP array. Genotyping-by-sequencing (GBS), a new methodology based on high-throughput sequencing, holds great promise for identification of high number of SNPs and construction of high density linkage maps. In this study, GBS was used to identify SNPs from an intra-specific sweet cherry cross. A total of 8,476 high quality SNPs were selected for mapping. The physical position for each SNP was determined using the peach genome, Peach v1.0, as reference, and a homogeneous distribution of markers along the eight peach scaffolds was obtained. On average, 65.6% of the SNPs were present in genic regions and 49.8% were located in exonic regions. In addition to the SNPs, a group of SSRs was also used for construction of linkage maps. Parental and consensus high density maps were constructed by genotyping 166 siblings from a 'Rainier' x 'Rivedel' (Ra x Ri) cross. Using Ra x Ri population, 462, 489 and 985 markers were mapped into eight linkage groups in 'Rainier', 'Rivedel' and the Ra x Ri map, respectively, with 80% of mapped SNPs located in genic regions. Obtained maps spanned 549.5, 582.6 and 731.3 cM for 'Rainier', 'Rivedel' and consensus maps, respectively, with an average distance of 1.2 cM between adjacent markers for both 'Rainier' and 'Rivedel' maps and of 0.7 cM for Ra x Ri map. High synteny and co-linearity was observed between obtained maps and with Peach v1.0. These new high density linkage maps provide valuable information on the sweet cherry genome, and serve as the basis for identification of QTLs and genes relevant for the breeding of the species.

  18. Linkage and association mapping of Arabidopsis thaliana flowering time in nature.

    Directory of Open Access Journals (Sweden)

    Benjamin Brachi

    2010-05-01

    Full Text Available Flowering time is a key life-history trait in the plant life cycle. Most studies to unravel the genetics of flowering time in Arabidopsis thaliana have been performed under greenhouse conditions. Here, we describe a study about the genetics of flowering time that differs from previous studies in two important ways: first, we measure flowering time in a more complex and ecologically realistic environment; and, second, we combine the advantages of genome-wide association (GWA and traditional linkage (QTL mapping. Our experiments involved phenotyping nearly 20,000 plants over 2 winters under field conditions, including 184 worldwide natural accessions genotyped for 216,509 SNPs and 4,366 RILs derived from 13 independent crosses chosen to maximize genetic and phenotypic diversity. Based on a photothermal time model, the flowering time variation scored in our field experiment was poorly correlated with the flowering time variation previously obtained under greenhouse conditions, reinforcing previous demonstrations of the importance of genotype by environment interactions in A. thaliana and the need to study adaptive variation under natural conditions. The use of 4,366 RILs provides great power for dissecting the genetic architecture of flowering time in A. thaliana under our specific field conditions. We describe more than 60 additive QTLs, all with relatively small to medium effects and organized in 5 major clusters. We show that QTL mapping increases our power to distinguish true from false associations in GWA mapping. QTL mapping also permits the identification of false negatives, that is, causative SNPs that are lost when applying GWA methods that control for population structure. Major genes underpinning flowering time in the greenhouse were not associated with flowering time in this study. Instead, we found a prevalence of genes involved in the regulation of the plant circadian clock. Furthermore, we identified new genomic regions lacking

  19. Construction of a high-density linkage map and fine mapping of QTLs for growth and gonad related traits in blunt snout bream

    OpenAIRE

    Shi-Ming Wan; Hong Liu; Bo-Wen Zhao; Chun-Hong Nie; Wei-Min Wang; Ze-Xia Gao

    2017-01-01

    High-density genetic maps based on SNPs are essential for fine mapping loci controlling specific traits for fish species. Using restriction-site associated DNA tag sequencing (RAD-Seq) technology, we identified 42,784 SNPs evenly distributed across the Megalobrama amblycephala genome. Based on 2 parents and 187 intra-specific hybridization progenies, a total of 14,648 high-confidence SNPs were assigned to 24 consensus linkage groups (LGs) of maternal and paternal map. The total length of the ...

  20. Exploring a Nonmodel Teleost Genome Through RAD Sequencing-Linkage Mapping in Common Pandora, Pagellus erythrinus and Comparative Genomic Analysis.

    Science.gov (United States)

    Manousaki, Tereza; Tsakogiannis, Alexandros; Taggart, John B; Palaiokostas, Christos; Tsaparis, Dimitris; Lagnel, Jacques; Chatziplis, Dimitrios; Magoulas, Antonios; Papandroulakis, Nikos; Mylonas, Constantinos C; Tsigenopoulos, Costas S

    2015-12-29

    Common pandora (Pagellus erythrinus) is a benthopelagic marine fish belonging to the teleost family Sparidae, and a newly recruited species in Mediterranean aquaculture. The paucity of genetic information relating to sparids, despite their growing economic value for aquaculture, provides the impetus for exploring the genomics of this fish group. Genomic tool development, such as genetic linkage maps provision, lays the groundwork for linking genotype to phenotype, allowing fine-mapping of loci responsible for beneficial traits. In this study, we applied ddRAD methodology to identify polymorphic markers in a full-sib family of common pandora. Employing the Illumina MiSeq platform, we sampled and sequenced a size-selected genomic fraction of 99 individuals, which led to the identification of 920 polymorphic loci. Downstream mapping analysis resulted in the construction of 24 robust linkage groups, corresponding to the karyotype of the species. The common pandora linkage map showed varying degrees of conserved synteny with four other teleost genomes, namely the European seabass (Dicentrarchus labrax), Nile tilapia (Oreochromis niloticus), stickleback (Gasterosteus aculeatus), and medaka (Oryzias latipes), suggesting a conserved genomic evolution in Sparidae. Our work exploits the possibilities of genotyping by sequencing to gain novel insights into genome structure and evolution. Such information will boost the study of cultured species and will set the foundation for a deeper understanding of the complex evolutionary history of teleosts.

  1. Exploring a Nonmodel Teleost Genome Through RAD Sequencing—Linkage Mapping in Common Pandora, Pagellus erythrinus and Comparative Genomic Analysis

    Directory of Open Access Journals (Sweden)

    Tereza Manousaki

    2016-03-01

    Full Text Available Common pandora (Pagellus erythrinus is a benthopelagic marine fish belonging to the teleost family Sparidae, and a newly recruited species in Mediterranean aquaculture. The paucity of genetic information relating to sparids, despite their growing economic value for aquaculture, provides the impetus for exploring the genomics of this fish group. Genomic tool development, such as genetic linkage maps provision, lays the groundwork for linking genotype to phenotype, allowing fine-mapping of loci responsible for beneficial traits. In this study, we applied ddRAD methodology to identify polymorphic markers in a full-sib family of common pandora. Employing the Illumina MiSeq platform, we sampled and sequenced a size-selected genomic fraction of 99 individuals, which led to the identification of 920 polymorphic loci. Downstream mapping analysis resulted in the construction of 24 robust linkage groups, corresponding to the karyotype of the species. The common pandora linkage map showed varying degrees of conserved synteny with four other teleost genomes, namely the European seabass (Dicentrarchus labrax, Nile tilapia (Oreochromis niloticus, stickleback (Gasterosteus aculeatus, and medaka (Oryzias latipes, suggesting a conserved genomic evolution in Sparidae. Our work exploits the possibilities of genotyping by sequencing to gain novel insights into genome structure and evolution. Such information will boost the study of cultured species and will set the foundation for a deeper understanding of the complex evolutionary history of teleosts.

  2. Exploring a Nonmodel Teleost Genome Through RAD Sequencing—Linkage Mapping in Common Pandora, Pagellus erythrinus and Comparative Genomic Analysis

    Science.gov (United States)

    Manousaki, Tereza; Tsakogiannis, Alexandros; Taggart, John B.; Palaiokostas, Christos; Tsaparis, Dimitris; Lagnel, Jacques; Chatziplis, Dimitrios; Magoulas, Antonios; Papandroulakis, Nikos; Mylonas, Constantinos C.; Tsigenopoulos, Costas S.

    2015-01-01

    Common pandora (Pagellus erythrinus) is a benthopelagic marine fish belonging to the teleost family Sparidae, and a newly recruited species in Mediterranean aquaculture. The paucity of genetic information relating to sparids, despite their growing economic value for aquaculture, provides the impetus for exploring the genomics of this fish group. Genomic tool development, such as genetic linkage maps provision, lays the groundwork for linking genotype to phenotype, allowing fine-mapping of loci responsible for beneficial traits. In this study, we applied ddRAD methodology to identify polymorphic markers in a full-sib family of common pandora. Employing the Illumina MiSeq platform, we sampled and sequenced a size-selected genomic fraction of 99 individuals, which led to the identification of 920 polymorphic loci. Downstream mapping analysis resulted in the construction of 24 robust linkage groups, corresponding to the karyotype of the species. The common pandora linkage map showed varying degrees of conserved synteny with four other teleost genomes, namely the European seabass (Dicentrarchus labrax), Nile tilapia (Oreochromis niloticus), stickleback (Gasterosteus aculeatus), and medaka (Oryzias latipes), suggesting a conserved genomic evolution in Sparidae. Our work exploits the possibilities of genotyping by sequencing to gain novel insights into genome structure and evolution. Such information will boost the study of cultured species and will set the foundation for a deeper understanding of the complex evolutionary history of teleosts. PMID:26715088

  3. The use of SNP markers for linkage mapping in diploid and tetraploid peanuts.

    Science.gov (United States)

    Bertioli, David J; Ozias-Akins, Peggy; Chu, Ye; Dantas, Karinne M; Santos, Silvio P; Gouvea, Ediene; Guimarães, Patricia M; Leal-Bertioli, Soraya C M; Knapp, Steven J; Moretzsohn, Marcio C

    2014-01-10

    Single nucleotide polymorphic markers (SNPs) are attractive for use in genetic mapping and marker-assisted breeding because they can be scored in parallel assays at favorable costs. However, scoring SNP markers in polyploid plants like the peanut is problematic because of interfering signal generated from the DNA bases that are homeologous to those being assayed. The present study used a previously constructed 1536 GoldenGate SNP assay developed using SNPs identified between two A. duranensis accessions. In this study, the performance of this assay was tested on two RIL mapping populations, one diploid (A. duranensis × A. stenosperma) and one tetraploid [A. hypogaea cv. Runner IAC 886 × synthetic tetraploid (A. ipaënsis × A. duranensis)(4×)]. The scoring was performed using the software GenomeStudio version 2011.1. For the diploid, polymorphic markers provided excellent genotyping scores with default software parameters. In the tetraploid, as expected, most of the polymorphic markers provided signal intensity plots that were distorted compared to diploid patterns and that were incorrectly scored using default parameters. However, these scorings were easily corrected using the GenomeStudio software. The degree of distortion was highly variable. Of the polymorphic markers, approximately 10% showed no distortion at all behaving as expected for single-dose markers, and another 30% showed low distortion and could be considered high-quality. The genotyped markers were incorporated into diploid and tetraploid genetic maps of Arachis and, in the latter case, were located almost entirely on A genome linkage groups.

  4. Aligning male and female linkage maps of apple (Malus pumila Mill.) using multi-allelic markers

    NARCIS (Netherlands)

    Maliepaard, C.A.; Alston, F.H.; Arkel, van G.; Brown, L.M.; Chevreau, E.; Dünemann, F.; Evans, K.M.; Gardiner, S.; Guilford, P.; Heusden, van A.W.; Janse, J.; Laurens, F.; Lynn, J.R.; Manganaris, A.G.; Nijs, den A.P.M.; Periam, N.; Rikkerink, E.; Roche, P.; Ryder, C.; Sansavini, S.; Schmidt, H.; Tartarini, S.; Verhaegh, J.J.; Vrielink-van Ginkel, M.; King, G.J.

    1998-01-01

    Linkage maps for the apple cultivars ‘Prima’ and ‘Fiesta’ were constructed using RFLP, RAPD, isozyme, AFLP, SCAR and microsatellite markers in a ‘Prima’בFiesta’ progeny of 152 individuals. Seventeen linkage groups, putatively corresponding to the seventeen haploid apple chromosomes, were obtained

  5. Genetic linkage maps, synteny and map based cloning

    DEFF Research Database (Denmark)

    Sandal, Niels Nørgaard; Sato, Shusei

    2014-01-01

    Nitrogen fixation is a very important trait in agriculture and nature. It is made possible through symbiosis between plants, mainly legumes, and microorganisms such as rhizobia. Like most plants, legumes have symbiosis with mycorrhizal fungi. In order to isolate the plant genes that are important...

  6. Evaluation of algorithms used to order markers on genetic maps.

    Science.gov (United States)

    Mollinari, M; Margarido, G R A; Vencovsky, R; Garcia, A A F

    2009-12-01

    When building genetic maps, it is necessary to choose from several marker ordering algorithms and criteria, and the choice is not always simple. In this study, we evaluate the efficiency of algorithms try (TRY), seriation (SER), rapid chain delineation (RCD), recombination counting and ordering (RECORD) and unidirectional growth (UG), as well as the criteria PARF (product of adjacent recombination fractions), SARF (sum of adjacent recombination fractions), SALOD (sum of adjacent LOD scores) and LHMC (likelihood through hidden Markov chains), used with the RIPPLE algorithm for error verification, in the construction of genetic linkage maps. A linkage map of a hypothetical diploid and monoecious plant species was simulated containing one linkage group and 21 markers with fixed distance of 3 cM between them. In all, 700 F(2) populations were randomly simulated with 100 and 400 individuals with different combinations of dominant and co-dominant markers, as well as 10 and 20% of missing data. The simulations showed that, in the presence of co-dominant markers only, any combination of algorithm and criteria may be used, even for a reduced population size. In the case of a smaller proportion of dominant markers, any of the algorithms and criteria (except SALOD) investigated may be used. In the presence of high proportions of dominant markers and smaller samples (around 100), the probability of repulsion linkage increases between them and, in this case, use of the algorithms TRY and SER associated to RIPPLE with criterion LHMC would provide better results.

  7. Fine mapping of quantitative trait loci using linkage disequilibria with closely linked marker loci

    NARCIS (Netherlands)

    Meuwissen, T.H.E.; Goddard, M.E.

    2000-01-01

    A multimarker linkage disequilibrium mapping method was developed for the fine mapping of quantitative trait loci (QTL) using a dense marker map. The method compares the expected covariances between haplotype effects given a postulated QTL position to the covariances that are found in the data. The

  8. Linkage disequilibrium and genome-wide association mapping in tetraploid wheat (Triticum turgidum L.).

    Science.gov (United States)

    Laidò, Giovanni; Marone, Daniela; Russo, Maria A; Colecchia, Salvatore A; Mastrangelo, Anna M; De Vita, Pasquale; Papa, Roberto

    2014-01-01

    Association mapping is a powerful tool for the identification of quantitative trait loci through the exploitation of the differential decay of linkage disequilibrium (LD) between marker loci and genes of interest in natural and domesticated populations. Using a sample of 230 tetraploid wheat lines (Triticum turgidum ssp), which included naked and hulled accessions, we analysed the pattern of LD considering 26 simple sequence repeats and 970 mostly mapped diversity array technology loci. In addition, to validate the potential for association mapping in durum wheat, we evaluated the same genotypes for plant height, heading date, protein content, and thousand-kernel weight. Molecular and phenotypic data were used to: (i) investigate the genetic and phenotypic diversity; (ii) study the dynamics of LD across the durum wheat genome, by investigating the patterns of LD decay; and (iii) test the potential of our panel to identify marker-trait associations through the analysis of four quantitative traits of major agronomic importance. Moreover, we compared and validated the association mapping results with outlier detection analysis based on population divergence. Overall, in tetraploid wheat, the pattern of LD is extremely population dependent and is related to the domestication and breeding history of durum wheat. Comparing our data with several other studies in wheat, we confirm the position of many major genes and quantitative trait loci for the traits considered. Finally, the analysis of the selection signature represents a very useful complement to validate marker-trait associations.

  9. An integrated linkage map reveals candidate genes underlying adaptive variation in Chinook salmon (Oncorhynchus tshawytscha)

    DEFF Research Database (Denmark)

    Mckinney, G. J.; Seeb, L. W.; Larson, W. A.

    2016-01-01

    Salmonids are an important cultural and ecological resource exhibiting near worldwide distribution between their native and introduced range. Previous research has generated linkage maps and genomic resources for several species as well as genome assemblies for two species. We first leveraged...... improvements in mapping and genotyping methods to create a dense linkage map for Chinook salmon Oncorhynchus tshawytscha by assembling family data from different sources. We successfully mapped 14 620 SNP loci including 2336 paralogs in subtelomeric regions. This improved map was then used as a foundation...... to integrate genomic resources for gene annotation and population genomic analyses. We anchored a total of 286 scaffolds from the Atlantic salmon genome to the linkage map to provide a framework for the placement 11 728 Chinook salmon ESTs. Previously identified thermotolerance QTL were found to colocalize...

  10. A genome-wide Asian genetic map and ethnic comparison: The GENDISCAN study

    Directory of Open Access Journals (Sweden)

    Sung Joohon

    2008-11-01

    Full Text Available Abstract Background Genetic maps provide specific positions of genetic markers, which are required for performing genetic studies. Linkage analyses of Asian families have been performed with Caucasian genetic maps, since appropriate genetic maps of Asians were not available. Different ethnic groups may have different recombination rates as a result of genomic variations, which would generate misspecification of the genetic map and reduce the power of linkage analyses. Results We constructed the genetic map of a Mongolian population in Asia with CRIMAP software. This new map, called the GENDISCAN map, is based on genotype data collected from 1026 individuals of 73 large Mongolian families, and includes 1790 total and 1500 observable meioses. The GENDISCAN map provides sex-averaged and sex-specific genetic positions of 1039 microsatellite markers in Kosambi centimorgans (cM with physical positions. We also determined 95% confidence intervals of genetic distances of the adjacent marker intervals. Genetic lengths of the whole genome, chromosomes and adjacent marker intervals are compared with those of Rutgers Map v.2, which was constructed based on Caucasian populations (Centre d'Etudes du Polymorphisme Humain (CEPH and Icelandic families by mapping methods identical to those of the GENDISCAN map, CRIMAP software and the Kosambi map function. Mongolians showed approximately 1.9 fewer recombinations per meiosis than Caucasians. As a result, genetic lengths of the whole genome and chromosomes of the GENDISCAN map are shorter than those of Rutgers Map v.2. Thirty-eight marker intervals differed significantly between the Mongolian and Caucasian genetic maps. Conclusion The new GENDISCAN map is applicable to the genetic study of Asian populations. Differences in the genetic distances between the GENDISCAN and Caucasian maps could facilitate elucidation of genomic variations between different ethnic groups.

  11. Construction of a linkage map and QTL analysis of horticultural traits for watermelon [Citrullus lanatus (THUNB.) MATSUM & NAKAI] using RAPD, RFLP and ISSR markers.

    Science.gov (United States)

    Hashizume, T; Shimamoto, I; Hirai, M

    2003-03-01

    We have been constructing linkage maps for watermelon ( Citrullus lanatus) on the basis of random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), inter-simple sequence repeats (ISSRs) and isozymes using an F(2) population derived from a crossing between a cultivated inbred line (H-7; C. lanatus) and an African wild form (SA-1; C. lanatus). A total of 120 F(2) plants was used for construction of a linkage map using 477 RAPDs, 53 RFLPs, 23 ISSRs and one isozyme markers. Linkage analysis revealed that 554 loci could be mapped to 11 linkage groups that extended for 2,384 centimorgans (cM). While a BC(1) population [(H-7 x SA-1) x H-7] consisting of 60 individuals was grown and scored for quantitative traits. Another linkage map with a total length of 1,729 cM was constructed in the BC(1) using genetic markers found to segregate in the F(2) population. A QTL analysis was applied by means of interval mapping for locating such agronomic traits as hardness of rind, Brix of flesh juice, flesh color (red and yellow) and rind color. The relative order of markers in the BC(1) map was essentially the same as that on the linkage map in the F(2). A total of five QTLs for four agronomic traits was detected. The QTL for hardness of rind was mapped on group 4. The linkage group 8 contained the QTL for sugar content of the flesh as expressed in Brix of the juice. The QTL for red flesh color was detected on groups 2 and 8. The QTL for rind color mapped on the group 3. The present map and QTL analysis may provide a useful tool for breeders by introducing valuable wild watermelon genes to cultivars.

  12. Genome survey and high-density genetic map construction provide genomic and genetic resources for the Pacific White Shrimp Litopenaeus vannamei.

    Science.gov (United States)

    Yu, Yang; Zhang, Xiaojun; Yuan, Jianbo; Li, Fuhua; Chen, Xiaohan; Zhao, Yongzhen; Huang, Long; Zheng, Hongkun; Xiang, Jianhai

    2015-10-27

    The Pacific white shrimp Litopenaeus vannamei is the dominant crustacean species in global seafood mariculture. Understanding the genome and genetic architecture is useful for deciphering complex traits and accelerating the breeding program in shrimp. In this study, a genome survey was conducted and a high-density linkage map was constructed using a next-generation sequencing approach. The genome survey was used to identify preliminary genome characteristics and to generate a rough reference for linkage map construction. De novo SNP discovery resulted in 25,140 polymorphic markers. A total of 6,359 high-quality markers were selected for linkage map construction based on marker coverage among individuals and read depths. For the linkage map, a total of 6,146 markers spanning 4,271.43 cM were mapped to 44 sex-averaged linkage groups, with an average marker distance of 0.7 cM. An integration analysis linked 5,885 genome scaffolds and 1,504 BAC clones to the linkage map. Based on the high-density linkage map, several QTLs for body weight and body length were detected. This high-density genetic linkage map reveals basic genomic architecture and will be useful for comparative genomics research, genome assembly and genetic improvement of L. vannamei and other penaeid shrimp species.

  13. Genome-wide linkage and association mapping identify susceptibility alleles in ABCC4 for Kawasaki disease

    NARCIS (Netherlands)

    Khor, Chiea Chuen; Davila, Sonia; Shimizu, Chisato; Sheng, Stephanie; Matsubara, Tomoyo; Suzuki, Yasuo; Newburger, Jane W.; Baker, Annette; Burgner, David; Breunis, Willemijn; Kuijpers, Taco; Wright, Victoria J.; Levin, Michael; Hibberd, Martin L.; Burns, Jane C.

    Background Kawasaki disease (KD) is a self limited vasculitis in which host genetics plays a prominent role. To further the understanding of the role of host genetics in KD, a three-stage genetic study was conducted that began with a family linkage study and ultimately involved more than 3000

  14. Genome-wide linkage and association mapping identify susceptibility alleles in ABCC4 for Kawasaki disease

    NARCIS (Netherlands)

    Khor, C.C.; Davila, S.; Shimizu, C.; Sheng, S.; Matsubara, T.; Suzuki, Y.; Newburger, J.W.; Baker, A.; Burgner, D.; Breunis, W.; Kuijpers, T.; Wright, V.J.; Levin, M.; Hibberd, M.L.; Burns, J.C.

    2011-01-01

    Kawasaki disease (KD) is a self limited vasculitis in which host genetics plays a prominent role. To further the understanding of the role of host genetics in KD, a three-stage genetic study was conducted that began with a family linkage study and ultimately involved more than 3000 individuals to

  15. Genome-wide linkage and association mapping identify susceptibility alleles in ABCC4 for Kawasaki disease

    NARCIS (Netherlands)

    Khor, C.C.; Davila, S.; Shimizu, C.; Sheng, S.; Matsubara, T.; Suzuki, Y.; Newburger, J.W.; Baker, A.; Burgner, D.; Breunis, W.; Kuijpers, T.; Wright, V.J.; Levin, M.; Hibberd, M.L.; Burns, J.C.

    2011-01-01

    Kawasaki disease (KD) is a self limited vasculitis in which host genetics plays a prominent role. To further the understanding of the role of host genetics in KD, a three-stage genetic study was conducted that began with a family linkage study and ultimately involved more than 3000 individuals to id

  16. Genome-wide linkage and association mapping identify susceptibility alleles in ABCC4 for Kawasaki disease

    NARCIS (Netherlands)

    Khor, Chiea Chuen; Davila, Sonia; Shimizu, Chisato; Sheng, Stephanie; Matsubara, Tomoyo; Suzuki, Yasuo; Newburger, Jane W.; Baker, Annette; Burgner, David; Breunis, Willemijn; Kuijpers, Taco; Wright, Victoria J.; Levin, Michael; Hibberd, Martin L.; Burns, Jane C.

    2011-01-01

    Background Kawasaki disease (KD) is a self limited vasculitis in which host genetics plays a prominent role. To further the understanding of the role of host genetics in KD, a three-stage genetic study was conducted that began with a family linkage study and ultimately involved more than 3000 indivi

  17. RAPD linkage mapping in a longleaf pine x slash pine F1 family.

    Science.gov (United States)

    Kubisiak, T L; Nelson, C D; Nance, W L; Stine, M

    1995-06-01

    Random amplified polymorphic DNAs (RAPDs) were used to construct linkage maps of the parent of a longleaf pine (Pinus palustris Mill.) slash pine (Pinus elliottii Englm.) F1 family. A total of 247 segregating loci [233 (1∶1), 14 (3∶1)] and 87 polymorphic (between parents), but non-segregating, loci were identified. The 233 loci segregating 1∶1 (testcross configuration) were used to construct parent-specific linkage maps, 132 for the longleaf-pine parent and 101 for the slash-pine parent. The resulting linkage maps consisted of 122 marker loci in 18 groups (three or more loci) and three pairs (1367.5 cM) for longleaf pine, and 91 marker loci in 13 groups and six pairs for slash pine (952.9 cM). Genome size estimates based on two-point linkage data ranged from 2348 to 2392 cM for longleaf pine, and from 2292 to 2372 cM for slash pine. Linkage of 3∶1 loci to testcross loci in each of the parental maps was used to infer further linkages within maps, as well as potentially homologous counterparts between maps. Three of the longleaf-pine linkage groups appear to be potentially homologous counterparts to four different slash-pine linkage groups. The number of heterozygous loci (previously testcross in parents) per F1 individual, ranged from 96 to 130. With the 87 polymorphic, but non-segregating, loci that should also be heterozygous in the F1 progeny, a maximum of 183-217 heterozygous loci could be available for mapping early height growth (EHG) loci and for applying genomic selection in backcross populations.

  18. Construction of SSR Genetic Linkage Map and Analysis of QTLs Related toβ-glucan Content of Naked Oat (Avena nuda L.)%裸燕麦SSR标记连锁群图谱的构建及β-葡聚糖含量QTL的定位

    Institute of Scientific and Technical Information of China (English)

    吴斌; 张茜; 宋高原; 陈新; 张宗文

    2014-01-01

    Objective]A molecular genetic linkage map for cultivated naked oat based on SSR markers was developed and Quantitative Trait Loci influencingβ-glucan content were identified, in order to facilitate the utilization of highβ-glucan content oat germplasm resources and provide a theoretical basis for oat molecular marker-assisted selection.[Method] Taken a segregation population of 215 F2:3 lines which originated from the cross with the highβ-glucan content local cultivar Xiayoumai was used as the male parent and improved cultivar Chi38 Youmai as the female as mapping population, a molecular genetic linkage map of oats with SSR markers was developed. The β-glucan content of segregation population was determined by the standard β-glucan measure method (AACC Method 32-23) which was published by American Association of Cereal Chemists and the QTLs for β-glucan content of oat were analyzed and identified by Composite Interval Mapping method. [Result] After detection of F2 progenies with 231 pairs of SSR primers, a total of 261 polymorphic markers were obtained. The polymorphic markers mentioned above were analyzed for their genetic linkage relationship by JoinMap 4.0 and finally the oat genetic linkage map was constructed. The map included 26 linkage group, 182 SSR markers and covers 1869.7cM of the whole genome. The average space between markers was 10.6 cM. The number of markers in each linkage group varied from 2 to 14 and the length of the linkage group varied from 10.6 to 235.1 cM. The results of the measurement of the parents and segregation population’sβ-glucan content showed thatβ-glucan content in the offspring groups presented as significant separation and continuous variation with variation coefficient of 18.72%, which indicated thatβ-glucan content traits are controlled by multiple genes of quantitative traits and the segregation population meets the requirements of QTL mapping. The SSR data were analyzed by QTL analysis software WinQTL Cart 2.5 and

  19. Refined mapping of the gene causing Familial Mediterranean fever, by linkage and homozygosity studies

    Energy Technology Data Exchange (ETDEWEB)

    Aksentijevich, I.; Pras, E.; Gruberg, L.; Helling, S.; Prosen, L.; Pras, M.; Kastner, D.L. (National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD (United States)); Shen, Y.; Holman, K.; Sutherland, G.R.; Richards, R.I. (Adelaide Children' s Hospital (Australia)); Ramsburg, M.; Dean, M. (Laboratory of Viral Carcinogenesis, Frederick, MD (United States)); Amos, C.I. (Laboratory of Skin Biology, Bethesda, MD (United States))

    1993-08-01

    Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by attacks of fever and serosal inflammation; the biochemical basis is unknown. The authors recently reported linkage of the gene causing FMF (designated [open quotes]MEF[close quotes]) to two markers on chromosome 16p. To map MEF more precisely, they have now tested nine 16p markers. Two-point and multipoint linkage analysis, as well as a study of recombinant haplotypes, placed MEF between D16S94 and D16S80, a genetic interval of about 9 cM. They also examined rates of homozygosity for markers in this region, among offspring of consanguineous marriages. For eight of nine markers, the rate of homozygosity among 26 affected inbred individuals was higher than that among their 20 unaffected sibs. Localizing MEF more precisely on the basis of homozygosity rates alone would be difficult, for two reasons: First, the FMF carrier frequency increases the chance that inbred offspring could have the disease without being homozygous by descent at MEF. Second, several of the markers in this region are relatively nonpolymorphic, with a high rate of homozygosity, regardless of their chromosomal location. 30 refs., 6 figs., 2 tabs.

  20. Linkage disequilibrium mapping places the gene causing familial Mediterranean fever close to D16S246

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. N.; Aksentijevich, I.; Pras, E. [National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD (United States)] [and others

    1996-03-01

    This report presents refined genetic mapping data for the gene causing familial Mediterranean fever (FMF), a recessively inherited disorder of inflammation. We sampled 65 Jewish, Armenian, and Arab families and typed them for eight markers from chromosome 16p. Using a new algorithm that permits multipoint calculations for a dense map of markers in consanguineous families, we obtained a maximal LOD score of 49.2 at a location 1.6 cM centromeric to D16S246. A specific haplotype at D16S283-D16S94-D16S246 was found in 76% of Moroccan and 32% of non-Moroccan Jewish carrier chromosomes, but this haplotype was not overrepresented in Armenian or Arab FMF carriers. Moreover, the 2.5-kb allele at D16S246 was significantly associated with FMF in Moroccan and non-Moroccan Jews but not in Armenians or Arabs. Since the Moroccan Jewish community represents a relatively recently established and genetically isolated founder population, we analyzed the Moroccan linkage-disequilibrium data by using Luria-Delbruck formulas and simulations based on a Poisson branching process. These methods place the FMF susceptibility gene within 0.305 cM of D16S246 (2-LOD-unit range 0.02-0.64 cM). 41 refs., 3 figs., 5 tabs.

  1. A gene-rich linkage map in the dioecious species Actinidia chinensis (kiwifruit reveals putative X/Y sex-determining chromosomes

    Directory of Open Access Journals (Sweden)

    Gill Geoffrey P

    2009-03-01

    Full Text Available Abstract Background The genus Actinidia (kiwifruit consists of woody, scrambling vines, native to China, and only recently propagated as a commercial crop. All species described are dioecious, but the genetic mechanism for sex-determination is unknown, as is the genetic basis for many of the cluster of characteristics making up the unique fruit. It is, however, an important crop in the New Zealand economy, and a classical breeding program would benefit greatly by knowledge of the trait alleles carried by both female and male parents. The application of marker assisted selection (MAS in seedling populations would also aid the accurate and efficient development of novel fruit types for the market. Results Gene-rich female, male and consensus linkage maps of the diploid species A. chinensis have been constructed with 644 microsatellite markers. The maps consist of twenty-nine linkage groups corresponding to the haploid number n = 29. We found that sex-linked sequence characterized amplified region (SCAR markers and the 'Flower-sex' phenotype consistently mapped to a single linkage group, in a subtelomeric region, in a section of inconsistent marker order. The region also contained markers of expressed genes, some of unknown function. Recombination, assessed by allelic distribution and marker order stability, was, in the remainder of the linkage group, in accordance with other linkage groups. Fully informative markers to other genes in this linkage group identified the comparative linkage group in the female map, where recombination ratios determining marker order were similar to the autosomes. Conclusion We have created genetic linkage maps that define the 29 linkage groups of the haploid genome, and have revealed the position and extent of the sex-determining locus in A. chinensis. As all Actinidia species are dioecious, we suggest that the sex-determining loci of other Actinidia species will be similar to that region defined in our maps. As the

  2. Viral Genetic Linkage Analysis in the Presence of Missing Data.

    Directory of Open Access Journals (Sweden)

    Shelley H Liu

    Full Text Available Analyses of viral genetic linkage can provide insight into HIV transmission dynamics and the impact of prevention interventions. For example, such analyses have the potential to determine whether recently-infected individuals have acquired viruses circulating within or outside a given community. In addition, they have the potential to identify characteristics of chronically infected individuals that make their viruses likely to cluster with others circulating within a community. Such clustering can be related to the potential of such individuals to contribute to the spread of the virus, either directly through transmission to their partners or indirectly through further spread of HIV from those partners. Assessment of the extent to which individual (incident or prevalent viruses are clustered within a community will be biased if only a subset of subjects are observed, especially if that subset is not representative of the entire HIV infected population. To address this concern, we develop a multiple imputation framework in which missing sequences are imputed based on a model for the diversification of viral genomes. The imputation method decreases the bias in clustering that arises from informative missingness. Data from a household survey conducted in a village in Botswana are used to illustrate these methods. We demonstrate that the multiple imputation approach reduces bias in the overall proportion of clustering due to the presence of missing observations.

  3. Constructing a high-density linkage map for Gossypium hirsutum ? Gossypium barbadense and identifying QTLs for lint percentage

    Institute of Scientific and Technical Information of China (English)

    Yuzhen Shi; Haihong Shang; Juwu Gong; Wankui Gong; Zemao Yang; Feiy Tang; Zhi Liu; Weiping Zhu; Jianxiong Jiang; Xiaonan Yu; Tao Wang; Wentan Li; Wei Wang; Tingting Chen; Kunbo Wang; Zhengsheng Zhang; Youlu Yuan; Aiguo Li; Ruihua Ge; Baocai Zhang; Junzhi Li; Guangping Liu; Junwen Li; Aiying Liu

    2015-01-01

    To introgress the good fiber quality and yield from Gossypium barbadense into a commercial Upland cotton variety, a high‐density simple sequence repeat (SSR) genetic linkage map was developed from a BC1F1 population of Gossypium hirsutum ? Gossypium barbadense. The map com-prised 2,292 loci and covered 5115.16 centiMorgan (cM) of the cotton AD genome, with an average marker interval of 2.23 cM. Of the marker order for 1,577 common loci on this new map, 90.36% agrees well with the marker order on the D genome sequence genetic map. Compared with five pub-lished high‐density SSR genetic maps, 53.14% of marker loci were newly discovered in this map. Twenty‐six quantitative trait loci (QTLs) for lint percentage (LP) were identified on nine chromosomes. Nine stable or common QTLs could be used for marker‐assisted selection. Fifty percent of the QTLs were from G. barbadense and increased LP by 1.07%–2.41%. These results indicated that the map could be used for screening chromosome substitution segments from G. barbadense in the Upland cotton background, identifying QTLs or genes from G. barbadense, and further developing the gene pyramiding effect for improving fiber yield and quality.

  4. Recombination patterns reveal information about centromere location on linkage maps

    DEFF Research Database (Denmark)

    Limborg, Morten T.; McKinney, Garrett J.; Seeb, Lisa W.

    2016-01-01

    . mykiss) characterized by low and unevenly distributed recombination – a general feature of male meiosis in many species. Further, a high frequency of double crossovers along chromosome arms in barley reduced resolution for locating centromeric regions on most linkage groups. Despite these limitations...

  5. The optimal design for hypothesis test and its application in genetic linkage analysis

    Institute of Scientific and Technical Information of China (English)

    XIE; Minyu(谢民育); LI; Zhaohai(李照海)

    2003-01-01

    This paper proposes a class of linear models with inequable variance, based on background in genetic linkage analysis, and considers the optimal design problem for the hypothesis test of the parameters in such models. To assess a design for the test, a frame of decision theory is established. Under this frame, an admissible minimax design is obtained. It is shown to be not only admissible and minimax in genetic linkage analysis, but best among a reasonable subclass of designs. The power of the test in genetic linkage analysis is substantially improved by using this optimal design.

  6. The sumLINK statistic for genetic linkage analysis in the presence of heterogeneity.

    Science.gov (United States)

    Christensen, G B; Knight, S; Camp, N J

    2009-11-01

    We present the "sumLINK" statistic--the sum of multipoint LOD scores for the subset of pedigrees with nominally significant linkage evidence at a given locus--as an alternative to common methods to identify susceptibility loci in the presence of heterogeneity. We also suggest the "sumLOD" statistic (the sum of positive multipoint LOD scores) as a companion to the sumLINK. sumLINK analysis identifies genetic regions of extreme consistency across pedigrees without regard to negative evidence from unlinked or uninformative pedigrees. Significance is determined by an innovative permutation procedure based on genome shuffling that randomizes linkage information across pedigrees. This procedure for generating the empirical null distribution may be useful for other linkage-based statistics as well. Using 500 genome-wide analyses of simulated null data, we show that the genome shuffling procedure results in the correct type 1 error rates for both the sumLINK and sumLOD. The power of the statistics was tested using 100 sets of simulated genome-wide data from the alternative hypothesis from GAW13. Finally, we illustrate the statistics in an analysis of 190 aggressive prostate cancer pedigrees from the International Consortium for Prostate Cancer Genetics, where we identified a new susceptibility locus. We propose that the sumLINK and sumLOD are ideal for collaborative projects and meta-analyses, as they do not require any sharing of identifiable data between contributing institutions. Further, loci identified with the sumLINK have good potential for gene localization via statistical recombinant mapping, as, by definition, several linked pedigrees contribute to each peak.

  7. Linkage mapping of the Mediterranean cypress, Cupressus sempervirens, based on molecular and morphological markers.

    Science.gov (United States)

    Manescu, C; Hamamouch, N; Maios, C; Harfouche, A; Doulis, A G; Aravanopoulos, F A

    2011-08-30

    Gene mapping for a Cupressus species is presented for the first time. Two linkage maps for the Mediterranean cypress (Cupressus sempervirens) varieties, C. sempervirens var. horizontalis and C. sempervirens var. pyramidalis, were constructed following the pseudo-testcross mapping strategy and employing RAPD, SCAR and morphological markers. A total of 427 loci (425 RAPDs, two SCARs) representing parents and F(1) progeny were screened for polymorphism with 32 random decamer and two SCAR primers. A morphological marker defined as "crown form" was also included. Of 274 polymorphic loci, the 188 that presented Mendelian inheritance formed the mapping dataset. Of these loci, 30% were mapped into seven linkage groups for the horizontalis (maternal) and four linkage groups for the pyramidalis (paternal) map. The putative "crown form" locus was included in a linkage group of both maps. The horizontalis and the pyramidalis maps covered 160.1 and 144.5 cM, respectively, while genome length was estimated to be 1696 cM for the former variety and 1373 cM for the latter. The four RAPD markers most tightly linked to crown form were cloned and converted to SCARs. Each of the cloned RAPD markers yielded two to three different sequences behaving as co-migrating fragments. Two SCAR markers, SC-D05(432) and SC-D09(667), produced amplified bands of the expected sizes and maintained linkage with the appropriate phenotype, but to a lesser extent compared to their original RAPD counterparts. These linkage maps represent a first step towards the localization of QTLs and genes controlling crown form and other polygenic traits in cypress.

  8. An autotetraploid linkage map of rose (Rosa hybrida validated using the strawberry (Fragaria vesca genome sequence.

    Directory of Open Access Journals (Sweden)

    Oron Gar

    Full Text Available Polyploidy is a pivotal process in plant evolution as it increase gene redundancy and morphological intricacy but due to the complexity of polysomic inheritance we have only few genetic maps of autopolyploid organisms. A robust mapping framework is particularly important in polyploid crop species, rose included (2n = 4x = 28, where the objective is to study multiallelic interactions that control traits of value for plant breeding. From a cross between the garden, peach red and fragrant cultivar Fragrant Cloud (FC and a cut-rose yellow cultivar Golden Gate (GG, we generated an autotetraploid GGFC mapping population consisting of 132 individuals. For the map we used 128 sequence-based markers, 141 AFLP, 86 SSR and three morphological markers. Seven linkage groups were resolved for FC (Total 632 cM and GG (616 cM which were validated by markers that segregated in both parents as well as the diploid integrated consensus map.The release of the Fragaria vesca genome, which also belongs to the Rosoideae, allowed us to place 70 rose sequenced markers on the seven strawberry pseudo-chromosomes. Synteny between Rosa and Fragaria was high with an estimated four major translocations and six inversions required to place the 17 non-collinear markers in the same order. Based on a verified linear order of the rose markers, we could further partition each of the parents into its four homologous groups, thus providing an essential framework to aid the sequencing of an autotetraploid genome.

  9. Chromosomal assignment of chicken clone contigs by extending the consensus linkage map

    NARCIS (Netherlands)

    Aerts, J.; Veenendaal, T.; Poel, van der J.J.; Crooijmans, R.P.M.A.; Groenen, M.A.M.

    2005-01-01

    The bacterial artificial clone-based physical map for chicken plays an important role in the integration of the consensus linkage map and the whole-genome shotgun sequence. It also provides a valuable resource for clone selection within applications such as fluorescent in situ hybridization and posi

  10. Genetic linkage between melanism and winglessness in the ladybird beetle Adalia bipunctata

    NARCIS (Netherlands)

    Lommen, S.T.E.; Jong, de P.W.; Koops, K.G.; Brakefield, P.M.

    2012-01-01

    We report a case of genetic linkage between the two major loci underlying different wing traits in the two-spot ladybird beetle, Adalia bipunctata (L.) (Coleoptera: Coccinellidae): melanism and winglessness. The loci are estimated to be 38.8 cM apart on one of the nine autosomes. This linkage is lik

  11. High-density Linkage Map of Cultivated Allotetraploid Cotton Based on SSR, TRAP, SRAP and AFLP Markers

    Institute of Scientific and Technical Information of China (English)

    Jiwen Yu; Shuxun Yu; Cairui Lu; Wu Wang; Shuli Fan; Meizhen Song; Zhongxu Lin; Xianlong Zhang; Jinfa Zhang

    2007-01-01

    A high-density linkage map was constructed for an F2 population derived from an interspecific cross of cultivated allotetraploid species between Gossyplum hirsutum L. and G. barbadense L. A total of 186 F2 individuals from the interspecific cross of "CRI 36 × Hai 7124" were genotyped at 1 252 polymorphic loci including a novel marker system,target region amplification polymorphism (TRAP). The map consists of 1 097 markers, including 697 simple sequence repeats (SSRs), 171 TRAPs, 129 sequence-related amplified polymorphisms, 98 amplified fragment length polymorphisms, and two morphological markers, and spanned 4 536.7 cM with an average genetic distance of 4.1 cM per marker. Using 45 duplicated SSR loci among chromosomes, 11 of the 13 pairs of homologous chromosomes were identified in tetraplold cotton. This map will provide an essential resource for high resolution mapping of quantitative trait loci and molecular breeding in cotton.

  12. Linkage mapping in the oilseed crop Jatropha curcas L. reveals a locus controlling the biosynthesis of phorbol esters which cause seed toxicity.

    Science.gov (United States)

    King, Andrew J; Montes, Luis R; Clarke, Jasper G; Affleck, Julie; Li, Yi; Witsenboer, Hanneke; van der Vossen, Edwin; van der Linde, Piet; Tripathi, Yogendra; Tavares, Evanilda; Shukla, Parul; Rajasekaran, Thirunavukkarasu; van Loo, Eibertus N; Graham, Ian A

    2013-10-01

    Current efforts to grow the tropical oilseed crop Jatropha curcas L. economically are hampered by the lack of cultivars and the presence of toxic phorbol esters (PE) within the seeds of most provenances. These PE restrict the conversion of seed cake into animal feed, although naturally occurring 'nontoxic' provenances exist which produce seed lacking PE. As an important step towards the development of genetically improved varieties of J. curcas, we constructed a linkage map from four F₂ mapping populations. The consensus linkage map contains 502 codominant markers, distributed over 11 linkage groups, with a mean marker density of 1.8 cM per unique locus. Analysis of the inheritance of PE biosynthesis indicated that this is a maternally controlled dominant monogenic trait. This maternal control is due to biosynthesis of the PE occurring only within maternal tissues. The trait segregated 3 : 1 within seeds collected from F₂ plants, and QTL analysis revealed that a locus on linkage group 8 was responsible for phorbol ester biosynthesis. By taking advantage of the draft genome assemblies of J. curcas and Ricinus communis (castor), a comparative mapping approach was used to develop additional markers to fine map this mutation within 2.3 cM. The linkage map provides a framework for the dissection of agronomic traits in J. curcas, and the development of improved varieties by marker-assisted breeding. The identification of the locus responsible for PE biosynthesis means that it is now possible to rapidly breed new nontoxic varieties.

  13. Expanding the genetic map of maize with the intermated B73 x Mo17 (IBM) population.

    Science.gov (United States)

    Lee, Michael; Sharopova, Natalya; Beavis, William D; Grant, David; Katt, Maria; Blair, Deborah; Hallauer, Arnel

    2002-01-01

    The effects of intermating on recombination and the development of linkage maps were assessed in maize. Progeny derived from a common population (B73 x Mo17) before and after five generations of intermating were genotyped at the same set of 190 RFLP loci. Intermating resulted in nearly a four-fold increase in the genetic map distance and increased the potential for improved genetic resolution in 91% of the intervals evaluated. This mapping population and related information should connect research involving dense genetic maps, physical mapping, gene isolation, comparative genomics, analysis of quantitative trait loci and investigations of heterosis.

  14. Combined linkage and association mapping of flowering time in Sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Cadic, Elena; Coque, Marie; Vear, Felicity; Grezes-Besset, Bruno; Pauquet, Jerôme; Piquemal, Joël; Lippi, Yannick; Blanchard, Philippe; Romestant, Michel; Pouilly, Nicolas; Rengel, David; Gouzy, Jerôme; Langlade, Nicolas; Mangin, Brigitte; Vincourt, Patrick

    2013-05-01

    Association mapping and linkage mapping were used to identify quantitative trait loci (QTL) and/or causative mutations involved in the control of flowering time in cultivated sunflower Helianthus annuus. A panel of 384 inbred lines was phenotyped through testcrosses with two tester inbred lines across 15 location × year combinations. A recombinant inbred line (RIL) population comprising 273 lines was phenotyped both per se and through testcrosses with one or two testers in 16 location × year combinations. In the association mapping approach, kinship estimation using 5,923 single nucleotide polymorphisms was found to be the best covariate to correct for effects of panel structure. Linkage disequilibrium decay ranged from 0.08 to 0.26 cM for a threshold of 0.20, after correcting for structure effects, depending on the linkage group (LG) and the ancestry of inbred lines. A possible hitchhiking effect is hypothesized for LG10 and LG08. A total of 11 regions across 10 LGs were found to be associated with flowering time, and QTLs were mapped on 11 LGs in the RIL population. Whereas eight regions were demonstrated to be common between the two approaches, the linkage disequilibrium approach did not detect a documented QTL that was confirmed using the linkage mapping approach.

  15. Indication of Genetic Linkage Map for Sunflower (Helianthus annuus L.) by SSR Markers%转Bt基因水稻与非转基因水稻在虫压下的适合度差异

    Institute of Scientific and Technical Information of China (English)

    张富丽; 雷绍荣; 刘勇; 郭灵安; 尹全; 宋君; 王东; 常丽娟; 刘文娟; 周西全

    2012-01-01

    以转胁抗虫水稻Bt63、R1、R2和非转基因常规水稻Ⅱ优838为试材,采用高、低两个不同虫害胁迫水平和转基因与非转基凶水稻相间种植方式,通过观察水稻植株营养生长、结实以及对螟虫危害的抗性表现等差异,研究比较晚外源基因插入后对水稻植株适合度的影响,以解转基因水稻的基因扩散效率和潜在生态风险。结果表明:在低虫害胁迫条件下,转胁基因水稻在植株分蘖数、生物量鲜重等营养生长指标方面与非转基因对照品系间无明显差异,但株高、穗长、穗重等指标不及对照,且R2和Bt63与对照间差异显著;在高虫害胁迫条件下,3个转胁基凶水稻品系的分蘖数、穗长、穗重等指标明显高于对照。而不同转基因品系株高适合度效应不同,这可能与受体品系本身的特性相关。3种转基因水稻的单株结实粒数、千粒重与对照在两种虫害胁迫条件下均无显著性差异,Bt基因对受体植株的结实影响不明显。在高虫害胁迫条件下,3种转&基因水稻的抗虫能力均显著优于非转基因水稻,表明髓基因对受体植株的抗虫性影响显著。本研究结果还表明转Bt基因水稻的适合度代价较小,预示了抗虫转基因水稻外源胁基因在一定环境条件下具有逃逸的可能,但这种风险比较小。%[Objective] This study aimed to improve density and practicality of the ge- netic map of sunflower (Helianthus annuus L.) by adding some SSR markers. [Method] A total of 123 F8 RILs populations derived from a cross between PAC-2 and RHA-266 were selected as the materials, and a total of 300 pairs of SSR primers were used to screen polymorphic markers between the parents and some of their RILs, and finally 51 pairs of the primers producing polymorphic patterns were selected to construct the genetic map of the RILs populations. [Result] Nineteen pairs of SSR primers did not generate

  16. Correlation of physical and genetic maps of human chromosome 16

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, G.R.

    1991-01-01

    This project aimed to divide chromosome 16 into approximately 50 intervals of {approximately}2Mb in size by constructing a series of mouse/human somatic cell hybrids each containing a rearranged chromosome 16. Using these hybrids, DNA probes would be regionally mapped by Southern blot or PCR analysis. Preference would be given to mapping probes which demonstrated polymorphisms for which the CEPH panel of families had been typed. This would allow a correlation of the physical and linkage maps of this chromosome. The aims have been substantially achieved. 49 somatic cell hybrids have been constructed which have allowed definition of 46, and potentially 57, different physical intervals on the chromosome. 164 loci have been fully mapped into these intervals. A correlation of the physical and genetic maps of the chromosome is in an advanced stage of preparation. The somatic cell hybrids constructed have been widely distributed to groups working on chromosome 16 and other genome projects.

  17. CRISPR-directed mitotic recombination enables genetic mapping without crosses.

    Science.gov (United States)

    Sadhu, Meru J; Bloom, Joshua S; Day, Laura; Kruglyak, Leonid

    2016-05-27

    Linkage and association studies have mapped thousands of genomic regions that contribute to phenotypic variation, but narrowing these regions to the underlying causal genes and variants has proven much more challenging. Resolution of genetic mapping is limited by the recombination rate. We developed a method that uses CRISPR (clustered, regularly interspaced, short palindromic repeats) to build mapping panels with targeted recombination events. We tested the method by generating a panel with recombination events spaced along a yeast chromosome arm, mapping trait variation, and then targeting a high density of recombination events to the region of interest. Using this approach, we fine-mapped manganese sensitivity to a single polymorphism in the transporter Pmr1. Targeting recombination events to regions of interest allows us to rapidly and systematically identify causal variants underlying trait differences.

  18. Construction of an EST-SSR-based interspecific transcriptome linkage map of fibre development in cotton

    Indian Academy of Sciences (India)

    Chuanxiang Liu; Daojun Yuan; Zhongxu Lin

    2014-12-01

    Quantitative trait locus (QTL) mapping is an important method in marker-assisted selection breeding. Many studies on the QTLs focus on cotton fibre yield and quality; however, most are conducted at the DNA level, which may reveal null QTLs. Hence, QTL mapping based on transcriptome maps at the cDNA level is often more reliable. In this study, an interspecific transcriptome map of allotetraploid cotton was developed based on an F2 population (Emian22 × 3-79) by amplifying cDNA using EST-SSRs. The map was constructed using cDNA obtained from developing fibres at five days post anthesis (DPA). A total of 1270 EST-SSRs were screened for polymorphisms between the mapping parents. The resulting transcriptome linkage map contained 242 markers that were distributed in 32 linkage groups (26 chromosomes). The full length of this map is 1938.72 cM with a mean marker distance of 8.01 cM. The functions of some ESTs have been annotated by exploring homologous sequences. Some markers were related to the differentiation and elongation of cotton fibre, while most were related to the basic metabolism. This study demonstrates that constructing a transcriptome linkage map by amplifying cDNAs using EST-SSRs is a simple and practical method as well as a powerful tool to map eQTLs for fibre quality and other traits in cotton.

  19. Marker-based linkage map of Andean common bean (Phaseolus vulgaris L. and mapping of QTLs underlying popping ability traits

    Directory of Open Access Journals (Sweden)

    Yuste-Lisbona Fernando J

    2012-08-01

    Full Text Available Abstract Background Nuña bean is a type of ancient common bean (Phaseolus vulgaris L. native to the Andean region of South America, whose seeds possess the unusual property of popping. The nutritional features of popped seeds make them a healthy low fat and high protein snack. However, flowering of nuña bean only takes place under short-day photoperiod conditions, which means a difficulty to extend production to areas where such conditions do not prevail. Therefore, breeding programs of adaptation traits will facilitate the diversification of the bean crops and the development of new varieties with enhanced healthy properties. Although the popping trait has been profusely studied in maize (popcorn, little is known about the biology and genetic basis of the popping ability in common bean. To obtain insights into the genetics of popping ability related traits of nuña bean, a comprehensive quantitative trait loci (QTL analysis was performed to detect single-locus and epistatic QTLs responsible for the phenotypic variance observed in these traits. Results A mapping population of 185 recombinant inbred lines (RILs derived from a cross between two Andean common bean genotypes was evaluated for three popping related traits, popping dimension index (PDI, expansion coefficient (EC, and percentage of unpopped seeds (PUS, in five different environmental conditions. The genetic map constructed included 193 loci across 12 linkage groups (LGs, covering a genetic distance of 822.1 cM, with an average of 4.3 cM per marker. Individual and multi-environment QTL analyses detected a total of nineteen single-locus QTLs, highlighting among them the co-localized QTLs for the three popping ability traits placed on LGs 3, 5, 6, and 7, which together explained 24.9, 14.5, and 25.3% of the phenotypic variance for PDI, EC, and PUS, respectively. Interestingly, epistatic interactions among QTLs have been detected, which could have a key role in the genetic control of

  20. Integration of microsatellite-based genetic maps for the turkey (Meleagris gallopavo).

    Science.gov (United States)

    Reed, K M; Chaves, L D; Knutson, T P; Krueth, S B; Ashwell, C M; Burt, D W

    2006-10-01

    Integration of turkey genetic maps and their associated markers is essential to increase marker density in support of map-based genetic studies. The objectives of this study were to integrate 2 microsatellite-based turkey genetic maps--the Roslin map and the University of Minnesota (UMN) map--by genotyping markers from the Roslin study on the mapping families of the UMN study. A total of 279 markers was tested, and 240 were subsequently screened for polymorphisms in the UMN/Nicholas Turkey Breeding Farms (NTBF) mapping families. Of the 240 markers, 89 were genetically informative and were used for genotyping the F2 offspring. Significant genetic linkages (log of odds > 3.0) were found for 84 markers from the Roslin study. BLASTn comparison of marker sequences with the draft assembly of the chicken genome found 263 significant matches. The combination of genetic and in silico mapping allowed for the alignment of all linkage groups of the Roslin map with those of the UMN map. With the addition of the markers from the Roslin map, 438 markers are now genetically linked in the UMN/NTBF families, and more than 1700 turkey sequences have now been assigned to likely positions in the chicken-genome sequence.

  1. High density SNP and SSR-based genetic maps of two independent oil palm hybrids

    NARCIS (Netherlands)

    Ting, N.C.; Jansen, J.; Mayes, S.; Massawe, F.; Sambanthamurthi, R.; Cheng-Li Ooi, L.; Chin, C.W.; Arulandoo, X.; Seng, T.Y.; Alwee, S.S.R.S.; Ithnin, M.; Singh, R.

    2014-01-01

    BACKGROUND: Oil palm is an important perennial oil crop with an extremely long selection cycle of 10 to 12 years. As such, any tool that speeds up its genetic improvement process, such as marker-assisted breeding is invaluable. Previously, genetic linkage maps based on AFLP, RFLP and SSR markers

  2. A High-Resolution SNP Array-Based Linkage Map Anchors a New Domestic Cat Draft Genome Assembly and Provides Detailed Patterns of Recombination.

    Science.gov (United States)

    Li, Gang; Hillier, LaDeana W; Grahn, Robert A; Zimin, Aleksey V; David, Victor A; Menotti-Raymond, Marilyn; Middleton, Rondo; Hannah, Steven; Hendrickson, Sher; Makunin, Alex; O'Brien, Stephen J; Minx, Pat; Wilson, Richard K; Lyons, Leslie A; Warren, Wesley C; Murphy, William J

    2016-06-01

    High-resolution genetic and physical maps are invaluable tools for building accurate genome assemblies, and interpreting results of genome-wide association studies (GWAS). Previous genetic and physical maps anchored good quality draft assemblies of the domestic cat genome, enabling the discovery of numerous genes underlying hereditary disease and phenotypes of interest to the biomedical science and breeding communities. However, these maps lacked sufficient marker density to order thousands of shorter scaffolds in earlier assemblies, which instead relied heavily on comparative mapping with related species. A high-resolution map would aid in validating and ordering chromosome scaffolds from existing and new genome assemblies. Here, we describe a high-resolution genetic linkage map of the domestic cat genome based on genotyping 453 domestic cats from several multi-generational pedigrees on the Illumina 63K SNP array. The final maps include 58,055 SNP markers placed relative to 6637 markers with unique positions, distributed across all autosomes and the X chromosome. Our final sex-averaged maps span a total autosomal length of 4464 cM, the longest described linkage map for any mammal, confirming length estimates from a previous microsatellite-based map. The linkage map was used to order and orient the scaffolds from a substantially more contiguous domestic cat genome assembly (Felis catus v8.0), which incorporated ∼20 × coverage of Illumina fragment reads. The new genome assembly shows substantial improvements in contiguity, with a nearly fourfold increase in N50 scaffold size to 18 Mb. We use this map to report probable structural errors in previous maps and assemblies, and to describe features of the recombination landscape, including a massive (∼50 Mb) recombination desert (of virtually zero recombination) on the X chromosome that parallels a similar desert on the porcine X chromosome in both size and physical location.

  3. The first genetic map of pigeon pea based on diversity arrays technology (DArT) markers

    Indian Academy of Sciences (India)

    Shi Ying Yang; Rachit A. Saxena; Pawan L. Kulwal; Gavin J. Ash; Anuja Dubey; John D. I. Harper; Hari D. Upadhyaya; Ragini Gothalwal; Andrzej Kilian; Rajeev K. Varshney

    2011-04-01

    With an objective to develop a genetic map in pigeon pea (Cajanus spp.), a total of 554 diversity arrays technology (DArT) markers showed polymorphism in a pigeon pea F2 mapping population of 72 progenies derived from an interspecific cross of ICP 28 (Cajanus cajan) and ICPW 94 (Cajanus scarabaeoides). Approximately 13% of markers did not conform to expected segregation ratio. The total number of DArT marker loci segregating in Mendelian manner was 405 with 73.1% ($P \\gt 0.001$) of DArT markers having unique segregation patterns. Two groups of genetic maps were generated using DArT markers. While the maternal genetic linkage map had 122 unique DArT maternal marker loci, the paternal genetic linkage map has a total of 172 unique DArT paternal marker loci. The length of these two maps covered 270.0 cM and 451.6 cM, respectively. These are the first genetic linkage maps developed for pigeon pea, and this is the first report of genetic mapping in any grain legume using diversity arrays technology.

  4. Linkage Map Construction and Quantitative Trait Loci Analysis for Bolting Based on a Double Haploid Population of Brassica rapa

    Institute of Scientific and Technical Information of China (English)

    Xu Yang; Yang-Jun Yu; Feng-Lan Zhang; Zhi-Rong Zou; Xiu-Yun Zhao; De-Shuang Zhang; Jia-Bing Xu

    2007-01-01

    Early bolting of Chinese cabbage (Brassica rapa L.) during spring cultivation often has detrimental effects on the yield and quality of the harvested products. Breeding late bolting varieties is a major objective of Chinese cabbage breeding programs. in order to analyze the genetic basis of bolting traits, a genetic map of B. rapa was constructed based on amplified fragment-length polymorphism (AFLP), sequence-related amplified polymorphism (SRAP), simple sequence repeat (SSR), random amplification of polymorphic DNA (RAPD), and isozyme markers. Marker analysis was carried out on 81 double haploid (DH) lines obtained by mlcrospore culture from F1 progeny of two homozygous parents: B. rapa L. ssp. pekinensis (BY) (an extra-early bolting Chinese cabbage line) and B. rapa L. ssp. rapifera (MM) (an extra-late bolting European turnip line). A total of 326 markers including 130 AFLPs, 123 SRAPs, 16 SSRs, 43RAPDs and 14 isozymes were used to construct a linkage map with 10 linkage groups covering 882 cM with an average distance of 2.71 cM between loci. The bolting trait of each DH line was evaluated by the bolting index under controlled conditions. Quantitative trait loci (QTL) analysis was conducted using multiple QTL model mapping with MapQTL5.0 software. Eight QTLs controlling bolting resistance were identified. These QTLs, accounting for 14.1% to 25.2% of the phenotyplc variation with positive additive effects, were distributed into three linkage groups. These results provide useful information for molecular marker-assisted selection of late bolting traits in Chinese cabbage breeding programs.

  5. Genome-wide characterization and linkage mapping of simple sequence repeats in mei (Prunus mume Sieb. et Zucc..

    Directory of Open Access Journals (Sweden)

    Lidan Sun

    Full Text Available Because of its popularity as an ornamental plant in East Asia, mei (Prunus mume Sieb. et Zucc. has received increasing attention in genetic and genomic research with the recent shotgun sequencing of its genome. Here, we performed the genome-wide characterization of simple sequence repeats (SSRs in the mei genome and detected a total of 188,149 SSRs occurring at a frequency of 794 SSR/Mb. Mononucleotide repeats were the most common type of SSR in genomic regions, followed by di- and tetranucleotide repeats. Most of the SSRs in coding sequences (CDS were composed of tri- or hexanucleotide repeat motifs, but mononucleotide repeats were always the most common in intergenic regions. Genome-wide comparison of SSR patterns among the mei, strawberry (Fragaria vesca, and apple (Malus×domestica genomes showed mei to have the highest density of SSRs, slightly higher than that of strawberry (608 SSR/Mb and almost twice as high as that of apple (398 SSR/Mb. Mononucleotide repeats were the dominant SSR motifs in the three Rosaceae species. Using 144 SSR markers, we constructed a 670 cM-long linkage map of mei delimited into eight linkage groups (LGs, with an average marker distance of 5 cM. Seventy one scaffolds covering about 27.9% of the assembled mei genome were anchored to the genetic map, depending on which the macro-colinearity between the mei genome and Prunus T×E reference map was identified. The framework map of mei constructed provides a first step into subsequent high-resolution genetic mapping and marker-assisted selection for this ornamental species.

  6. Linkage analysis and physical mapping near the gene for x-linked agammaglobulinemia at Xq22

    Energy Technology Data Exchange (ETDEWEB)

    Parolini, O.; Lassiter, G.L.; Henry, M.J.; Conley, M.E. (Univ. of Tennessee College of Medicine, Memphis (United States) St. Jude Children' s Research Hospital, Memphis, TN (United States)); Hejtmancik, J.F. (National Inst. of Health, Bethesda, MD (United States)); Allen, R.C.; Belmont, J.W. (Baylor College of Medicine, Houston, TX (United States)); Barker, D.F. (Univ. of Utah, Salt Lake City (United States))

    1993-02-01

    The gene for x-linked agammaglobulinemia (XLA) has been mapped to Xq22. No recombinations have been reported between the gene and the prob p212 at DXS178; however, this probe is informative in only 30-40% of women and the reported flanking markers, DXS3 and DXS94, and 10-15 cM apart. To identify additional probes that might be useful in genetic counseling, we examined 11 polymorphisms that have been mapped to the Xq21.3-q22 region in 13 families with XLA. In addition, pulsed-field gel electrophoresis and yeast artificial chromosomes (YACs) were used to further characterize the segman of DNA within which the gene for SLA must lie. The results demonstrated that DXS366 and DXS442, which share a 430-kb pulsed-field fragment, could replace DXS3 as proximal flanking markers. Probes at DXS178 and DXS265 identified the same 145-kb pulsed-field fragment, and both loci were contained within a 200-kb YAC identified with the probe p212. A highly polymorphic CA repeat (DCS178CA) was isolated from one end of this YAC and used in linkage analysis. Probes at DXS101 and DXS328 shared several pulsed-field fragments, the smallest of which was 250 kb. No recombinations were seen between XLA and the DXS178-DXS265-DXS178CA complex, DXS101, DXS328, DXS87, or the gene for proteolipid protein (PLP). Key crossovers, when combined with the linkage data from families with Alport syndrome, suggested the following order of loci: cen-DXS3-DXS366-DXS442-(PLP, DXS101, DXS328, DXS178-DXS265-DXS178CA complex, XL)-(DXS87, DXS94)-DXS327-(DXS350, DXS362)-tel. Our studies also limit the segment of DNA within which the XLA gene must lie to the 3- to 4-cM distance between DCS442 and DXS94 and they identify and orient polymorphisms that can be used in genetic counseling not only for XLA but also for Pelizaeus-Merzbacher disease (PLP deficiency), Alport syndrome (COL4A5 deficiency), and Fabry disease ([alpha]-galactosidase A difficiency). 31 refs., 5 figs., 2 tabs.

  7. High-density linkage map construction and mapping of seed trait QTLs in chickpea (Cicer arietinum L.) using Genotyping-by-Sequencing (GBS).

    Science.gov (United States)

    Verma, Subodh; Gupta, Shefali; Bandhiwal, Nitesh; Kumar, Tapan; Bharadwaj, Chellapilla; Bhatia, Sabhyata

    2015-12-03

    This study reports the use of Genotyping-by-Sequencing (GBS) for large-scale SNP discovery and simultaneous genotyping of recombinant inbred lines (RILs) of an intra-specific mapping population of chickpea contrasting for seed traits. A total of 119,672 raw SNPs were discovered, which after stringent filtering revealed 3,977 high quality SNPs of which 39.5% were present in genic regions. Comparative analysis using physically mapped marker loci revealed a higher degree of synteny with Medicago in comparison to soybean. The SNP genotyping data was utilized to construct one of the most saturated intra-specific genetic linkage maps of chickpea having 3,363 mapped positions including 3,228 SNPs on 8 linkage groups spanning 1006.98 cM at an average inter marker distance of 0.33 cM. The map was utilized to identify 20 quantitative trait loci (QTLs) associated with seed traits accounting for phenotypic variations ranging from 9.97% to 29.71%. Analysis of the genomic sequence corresponding to five robust QTLs led to the identification of 684 putative candidate genes whose expression profiling revealed that 101 genes exhibited seed specific expression. The integrated approach utilizing the identified QTLs along with the available genome and transcriptome could serve as a platform for candidate gene identification for molecular breeding of chickpea.

  8. A consensus linkage map for molecular markers and Quantitative Trait Loci associated with economically important traits in melon (Cucumis melo L.

    Directory of Open Access Journals (Sweden)

    Schaffer Arthur

    2011-07-01

    Full Text Available Abstract Background A number of molecular marker linkage maps have been developed for melon (Cucumis melo L. over the last two decades. However, these maps were constructed using different marker sets, thus, making comparative analysis among maps difficult. In order to solve this problem, a consensus genetic map in melon was constructed using primarily highly transferable anchor markers that have broad potential use for mapping, synteny, and comparative quantitative trait loci (QTL analysis, increasing breeding effectiveness and efficiency via marker-assisted selection (MAS. Results Under the framework of the International Cucurbit Genomics Initiative (ICuGI, http://www.icugi.org, an integrated genetic map has been constructed by merging data from eight independent mapping experiments using a genetically diverse array of parental lines. The consensus map spans 1150 cM across the 12 melon linkage groups and is composed of 1592 markers (640 SSRs, 330 SNPs, 252 AFLPs, 239 RFLPs, 89 RAPDs, 15 IMAs, 16 indels and 11 morphological traits with a mean marker density of 0.72 cM/marker. One hundred and ninety-six of these markers (157 SSRs, 32 SNPs, 6 indels and 1 RAPD were newly developed, mapped or provided by industry representatives as released markers, including 27 SNPs and 5 indels from genes involved in the organic acid metabolism and transport, and 58 EST-SSRs. Additionally, 85 of 822 SSR markers contributed by Syngenta Seeds were included in the integrated map. In addition, 370 QTL controlling 62 traits from 18 previously reported mapping experiments using genetically diverse parental genotypes were also integrated into the consensus map. Some QTL associated with economically important traits detected in separate studies mapped to similar genomic positions. For example, independently identified QTL controlling fruit shape were mapped on similar genomic positions, suggesting that such QTL are possibly responsible for the phenotypic variability

  9. A consensus linkage map for molecular markers and Quantitative Trait Loci associated with economically important traits in melon (Cucumis melo L.)

    Science.gov (United States)

    2011-01-01

    Background A number of molecular marker linkage maps have been developed for melon (Cucumis melo L.) over the last two decades. However, these maps were constructed using different marker sets, thus, making comparative analysis among maps difficult. In order to solve this problem, a consensus genetic map in melon was constructed using primarily highly transferable anchor markers that have broad potential use for mapping, synteny, and comparative quantitative trait loci (QTL) analysis, increasing breeding effectiveness and efficiency via marker-assisted selection (MAS). Results Under the framework of the International Cucurbit Genomics Initiative (ICuGI, http://www.icugi.org), an integrated genetic map has been constructed by merging data from eight independent mapping experiments using a genetically diverse array of parental lines. The consensus map spans 1150 cM across the 12 melon linkage groups and is composed of 1592 markers (640 SSRs, 330 SNPs, 252 AFLPs, 239 RFLPs, 89 RAPDs, 15 IMAs, 16 indels and 11 morphological traits) with a mean marker density of 0.72 cM/marker. One hundred and ninety-six of these markers (157 SSRs, 32 SNPs, 6 indels and 1 RAPD) were newly developed, mapped or provided by industry representatives as released markers, including 27 SNPs and 5 indels from genes involved in the organic acid metabolism and transport, and 58 EST-SSRs. Additionally, 85 of 822 SSR markers contributed by Syngenta Seeds were included in the integrated map. In addition, 370 QTL controlling 62 traits from 18 previously reported mapping experiments using genetically diverse parental genotypes were also integrated into the consensus map. Some QTL associated with economically important traits detected in separate studies mapped to similar genomic positions. For example, independently identified QTL controlling fruit shape were mapped on similar genomic positions, suggesting that such QTL are possibly responsible for the phenotypic variability observed for this trait in

  10. Joint multi-population analysis for genetic linkage of bipolar disorder or "wellness" to chromosome 4p.

    Science.gov (United States)

    Visscher, P M; Haley, C S; Ewald, H; Mors, O; Egeland, J; Thiel, B; Ginns, E; Muir, W; Blackwood, D H

    2005-02-05

    To test the hypothesis that the same genetic loci confer susceptibility to, or protection from, disease in different populations, and that a combined analysis would improve the map resolution of a common susceptibility locus, we analyzed data from three studies that had reported linkage to bipolar disorder in a small region on chromosome 4p. Data sets comprised phenotypic information and genetic marker data on Scottish, Danish, and USA extended pedigrees. Across the three data sets, 913 individuals appeared in the pedigrees, 462 were classified, either as unaffected (323) or affected (139) with unipolar or bipolar disorder. A consensus linkage map was created from 14 microsatellite markers in a 33 cM region. Phenotypic and genetic data were analyzed using a variance component (VC) and allele sharing method. All previously reported elevated test statistics in the region were confirmed with one or both analysis methods, indicating the presence of one or more susceptibility genes to bipolar disorder in the three populations in the studied chromosome segment. When the results from both the VC and allele sharing method were considered, there was strong evidence for a susceptibility locus in the data from Scotland, some evidence in the data from Denmark and relatively less evidence in the data from the USA. The test statistics from the Scottish data set dominated the test statistics from the other studies, and no improved map resolution for a putative genetic locus underlying susceptibility in all three studies was obtained. Studies reporting linkage to the same region require careful scrutiny and preferably joint or meta analysis on the same basis in order to ensure that the results are truly comparable. (c) 2004 Wiley-Liss, Inc.

  11. Pseudovitamin D deficient rickets (PDDR). Linkage disequilibrium mapping in young populations

    Energy Technology Data Exchange (ETDEWEB)

    Labuda, M.; Korab-Laskowska, M.; Labuda, D. [McGill Univ. (Canada)] [and others

    1994-09-01

    PDDR is an autosomal recessive disorder with elevated prevalence in French Canadians. The condition is believed to be due to a deficient renal 25(OH)-vitamin D 1-alpha hydroxylase, but its underlying molecular defect is unknown. By linkage analysis we have earlier mapped PDDR to human chromosome 12q14. Using recently developed microsatellite markers we narrowed down the disease locus to a 5.6 cM interval between two clusters of loci: 234tf12, 207yh10, 249vf9, 329zh9, on proximal, and 259zc9 and 184yf2 on the distal side. Further refinement of the PDDR locus was obtained from analysis of those markers on 85 French Canadian PDDR chromosomes by linkage disequilibrium (LD). Ten-marker haplotype analysis for all chromosomes allowed to divide this sample into two groups, one of Saguenay-Lac St. Jean-Charlevoix (SLSJ-Ch), the other from Nova Scotia and New Brunswick (NS, NB). All SLSJ-Ch PDDR chromosomes shared an identical haplotype for markers 172x38, 184yf2, 259zc9, pointing to a single founder in this population. In the NS, NB group, the founder effect was also pronounced; however, the link of 2 PDDR chromosomes to either of these groups remains to be elucidated. In the absence of recombination in 12 generations of the SLSJ-Ch population, the genetic distance between PDDR and markers 172xd8, 184yf2, 259zc9 was estimated to be less than 0.4 cM. Finally the marker 207va9 was found to be the closest proximal one based on one recombination in a Polish PDDR family, its CEPH map position as well as its localization on the same YAC together with the distal markers 184yf2, 309xh1 and the marker 172xd8, probably the closest to the PDDR gene. Our study clearly shows the potential of LD for mapping human disorders in populations as young as 10-12 generations. Here it allowed narrowing PDDR position down to a single YAC.

  12. Genetic mapping of the dentinogenesis imperfecta type II locus

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, A.H.; Dixon, M.J. [Univ. of Manchester (United Kingdom); Scherpbier-Heddema, T. [Fox Chase Cancer Center, Philadelphia, PA (United States)] [and others

    1995-10-01

    Dentinogenesis imperfecta type II (DGI-II) is an autosomal dominant disorder of dentin formation, which has previously been mapped to chromosome 4q12-21. In the current study, six novel short tandem-repeat polymorphisms (STRPs) have been isolated, five of which show significant evidence of linkage to DGI-II. To determine the order of the STRPs and define the genetic distance between them, nine loci (including polymorphisms for two known genes) were mapped through the CEPH reference pedigrees. The resulting genetic map encompasses 16.3 cM on the sex-averaged map. To combine this map with a physical map of the region, all of the STRPs were mapped through a somatic cell hybrid panel. The most likely location for the DGI-II locus within the fixed marker map is in the D4S2691-D4S2692 interval of 6.6 cM. The presence of a marker that shows no recombination with the DGI-II phenotype between the flanking markers provides an important anchor point for the creation of physical continuity across the DGI-II candidate region. 38 refs., 4 figs., 2 tabs.

  13. Construction of AFLP-based genetic linkase maps for the Chinese shrimp Fenneropaeneus chinensis

    Institute of Scientific and Technical Information of China (English)

    TIAN Yi; KONG Jie; WANG WeiJi

    2008-01-01

    Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in China. A genetic linkage map is essential for improving the efficiency of its breeding by marker-as-sisted selection and identifying commercially important genes. Linkage maps of F. Chinensis were constructed with an F2 mapping population (110 progenies) using amplified fragment length polymor-phic (AFLP) marker in this study. Fifty-five AFLP primer combinations produced 532 AFLP markers fitting for map strategy in mapping family. The markers with 3:1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1:1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103 markers that formed 28 linkage groups, covering a total length of 1090 cM. All mark-ers were linked with the linkage groups. Segregation distortion was observed for 6 of 103 markers in the female map. The average distance between markers was 14.53 cM and ranged from 4.4 to 24.8 cM. The male map included 144 markers that formed 35 linkage groups. Ten markers remained unlinked in male map. Segregation distortion was observed for 7 of 144 markers in the male map. The total dis-tance of male map covered 1617 cM. The average distance between markers was 16.36 cM. The male map was 32.6% longer than the female map, which may reflect sex-specific recombination rates in Chinese shrimp. The common map was composed of 216 markers, including in 44 linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.42 cM. An average estimated genome size for the Chinese shrimp was 2420 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chi-nese shrimp maps. The linkage analysis

  14. A microsatellite-based consensus linkage map for species of Eucalyptus and a novel set of 230 microsatellite markers for the genus

    Directory of Open Access Journals (Sweden)

    Williams Emlyn R

    2006-09-01

    Full Text Available Abstract Background Eucalypts are the most widely planted hardwood trees in the world occupying globally more than 18 million hectares as an important source of carbon neutral renewable energy and raw material for pulp, paper and solid wood. Quantitative Trait Loci (QTLs in Eucalyptus have been localized on pedigree-specific RAPD or AFLP maps seriously limiting the value of such QTL mapping efforts for molecular breeding. The availability of a genus-wide genetic map with transferable microsatellite markers has become a must for the effective advancement of genomic undertakings. This report describes the development of a novel set of 230 EMBRA microsatellites, the construction of the first comprehensive microsatellite-based consensus linkage map for Eucalyptus and the consolidation of existing linkage information for other microsatellites and candidate genes mapped in other species of the genus. Results The consensus map covers ~90% of the recombining genome of Eucalyptus, involves 234 mapped EMBRA loci on 11 linkage groups, an observed length of 1,568 cM and a mean distance between markers of 8.4 cM. A compilation of all microsatellite linkage information published in Eucalyptus allowed us to establish the homology among linkage groups between this consensus map and other maps published for E. globulus. Comparative mapping analyses also resulted in the linkage group assignment of other 41 microsatellites derived from other Eucalyptus species as well as candidate genes and QTLs for wood and flowering traits published in the literature. This report significantly increases the availability of microsatellite markers and mapping information for species of Eucalyptus and corroborates the high conservation of microsatellite flanking sequences and locus ordering between species of the genus. Conclusion This work represents an important step forward for Eucalyptus comparative genomics, opening stimulating perspectives for evolutionary studies and

  15. Fine mapping of multiple QTL using combined linkage and linkage disequilibrium mapping – A comparison of single QTL and multi QTL methods

    Directory of Open Access Journals (Sweden)

    Meuwissen Theo HE

    2007-04-01

    Full Text Available Abstract Two previously described QTL mapping methods, which combine linkage analysis (LA and linkage disequilibrium analysis (LD, were compared for their ability to detect and map multiple QTL. The methods were tested on five different simulated data sets in which the exact QTL positions were known. Every simulated data set contained two QTL, but the distances between these QTL were varied from 15 to 150 cM. The results show that the single QTL mapping method (LDLA gave good results as long as the distance between the QTL was large (> 90 cM. When the distance between the QTL was reduced, the single QTL method had problems positioning the two QTL and tended to position only one QTL, i.e. a "ghost" QTL, in between the two real QTL positions. The multi QTL mapping method (MP-LDLA gave good results for all evaluated distances between the QTL. For the large distances between the QTL (> 90 cM the single QTL method more often positioned the QTL in the correct marker bracket, but considering the broader likelihood peaks of the single point method it could be argued that the multi QTL method was more precise. Since the distances were reduced the multi QTL method was clearly more accurate than the single QTL method. The two methods combine well, and together provide a good tool to position single or multiple QTL in practical situations, where the number of QTL and their positions are unknown.

  16. Use of linkage disequilibrium approaches to map genes for bipolar disorder in the Costa Rican population

    NARCIS (Netherlands)

    Escamilla, MA; Spesny, M; Reus, [No Value; Gallegos, A; Meza, L; Molina, J; Sandkuijl, LA; Fournier, E; Leon, PE; Smith, LB; Freimer, NB

    1996-01-01

    Linkage disequilibrium (LD) analysis provides a powerful means for screening the genome to map the location of disease genes, such as those for bipolar disorder (BP), As described in this paper, the population of the Central Valley of Costa Rica, which is descended from a small number of founders, s

  17. Construction of Molecular Genetic Linkage Map Based on an RIL Population of Rice and Detection of QTLs for Tiller Angle%水稻重组自交系分子遗传图谱构建及分蘖角的QTL检测

    Institute of Scientific and Technical Information of China (English)

    张亚东; 董少玲; 张颖慧; 陈涛; 赵庆勇; 朱镇; 周丽慧; 姚姝; 赵凌

    2013-01-01

    In this study,an RIL (recombinant inbred line) population containing 240 lines was developed by single seed descent method (SSD) based on a parent combination of small-grain indica cultivar Kasalath and large-grain japanica cultivar TD70 with significant differences in plant type traits,to construct the molecular genetic linkage map.Totally 838 SSR (Simple Sequence Repeat) markers were used for polymorphism screening between parents,302 SSR markers with polymorphism were detected,with a frequency of 36.04%; 141 SSR markers with clear amplified bands and uniform distribution in the genome were finally used for genotype analysis of the RIL population.According to the experimental results,the frequency of male and female genotype in this RIL population was respectively 53% and 47%,suggesting good balance in population structure.A molecular genetic linkage map of rice was constructed by 141 markers based on a RIL population of 240 lines,with a total genetic distance of about 1 832.47 cM covering all 12 chromosomes,an average genetic distance between markers of 12.70 cM and a range of genetic distance between markers of 0.43-36.11 cM,which is consistent with basic requirements of quantitative trait locus (QTL) mapping.Except for few markers on chromosomes 1 and 8,the order and location of markers is similar to the published sequences of Nipponbare.QTL analysis for the tiller angle was conducted with this RIL population of 240 lines,and results showed that three QTLs controlling tiller angle were detected on chromosome 8,9 and 11,which were named qTA8,qTA9 and qTA11,with a contribution rate of 4.10%,26.08% and 4.35%,respectively.To be specific,qTA9 contained Tiller Angle Controlling (TAC1) gene.The construction of this molecular genetic linkage map laid the foundation for genetic analysis and QTL mapping of various traits in the progeny of indica and japonica.%利用株型差异显著的特大粒粳稻品系TD70和籼稻小粒品种Kasalath为亲本配制组

  18. Construction of High Density Sweet Cherry (Prunus avium L. Linkage Maps Using Microsatellite Markers and SNPs Detected by Genotyping-by-Sequencing (GBS.

    Directory of Open Access Journals (Sweden)

    Verónica Guajardo

    Full Text Available Linkage maps are valuable tools in genetic and genomic studies. For sweet cherry, linkage maps have been constructed using mainly microsatellite markers (SSRs and, recently, using single nucleotide polymorphism markers (SNPs from a cherry 6K SNP array. Genotyping-by-sequencing (GBS, a new methodology based on high-throughput sequencing, holds great promise for identification of high number of SNPs and construction of high density linkage maps. In this study, GBS was used to identify SNPs from an intra-specific sweet cherry cross. A total of 8,476 high quality SNPs were selected for mapping. The physical position for each SNP was determined using the peach genome, Peach v1.0, as reference, and a homogeneous distribution of markers along the eight peach scaffolds was obtained. On average, 65.6% of the SNPs were present in genic regions and 49.8% were located in exonic regions. In addition to the SNPs, a group of SSRs was also used for construction of linkage maps. Parental and consensus high density maps were constructed by genotyping 166 siblings from a 'Rainier' x 'Rivedel' (Ra x Ri cross. Using Ra x Ri population, 462, 489 and 985 markers were mapped into eight linkage groups in 'Rainier', 'Rivedel' and the Ra x Ri map, respectively, with 80% of mapped SNPs located in genic regions. Obtained maps spanned 549.5, 582.6 and 731.3 cM for 'Rainier', 'Rivedel' and consensus maps, respectively, with an average distance of 1.2 cM between adjacent markers for both 'Rainier' and 'Rivedel' maps and of 0.7 cM for Ra x Ri map. High synteny and co-linearity was observed between obtained maps and with Peach v1.0. These new high density linkage maps provide valuable information on the sweet cherry genome, and serve as the basis for identification of QTLs and genes relevant for the breeding of the species.

  19. Assessing microsatellite linkage disequilibrium in wild, cultivated, and mapping populations of Theobroma cacao L and its impact on association mapping

    Science.gov (United States)

    Linkage disequilibrium (LD) is the nonrandom association of alleles and loci within sets of genetic data and when measured over the genomes of a species can provide important indications for how future association analyses should proceed. This information can be advantageous especially for slow-gro...

  20. Linkage disequilibrium and the genetic distance in livestock populations: the impact of inbreeding

    Directory of Open Access Journals (Sweden)

    Baret Philippe V

    2004-05-01

    Full Text Available Abstract Genome-wide linkage disequilibrium (LD is subject to intensive investigation in human and livestock populations since it can potentially reveal aspects of a population history, permit to date them and help in fine-gene mapping. The most commonly used measure of LD between multiallelic loci is the coefficient D'. Data based on D' were recently published in humans, livestock and model animals. However, the properties of this coefficient are not well understood. Its sampling distribution and variance has received recent attention, but its expected behaviour with respect to genetic or physical distance remains unknown. Using stochastic simulations of populations having a finite size, we show that D' fits an exponential function having two parameters of simple biological interpretation: the residual value (rs towards which D' tends as the genetic distance increases and the distance R at which this value is reached. Properties of this model are evaluated as a function of the inbreeding coefficient (F. It was found that R and rs increase when F increases. The proposed model offers opportunities to better understand the patterns and the origins of LD in different populations and along different chromosomes.

  1. Linkage disequilibrium-based quality control for large-scale genetic studies.

    Directory of Open Access Journals (Sweden)

    Paul Scheet

    2008-08-01

    Full Text Available Quality control (QC is a critical step in large-scale studies of genetic variation. While, on average, high-throughput single nucleotide polymorphism (SNP genotyping assays are now very accurate, the errors that remain tend to cluster into a small percentage of "problem" SNPs, which exhibit unusually high error rates. Because most large-scale studies of genetic variation are searching for phenomena that are rare (e.g., SNPs associated with a phenotype, even this small percentage of problem SNPs can cause important practical problems. Here we describe and illustrate how patterns of linkage disequilibrium (LD can be used to improve QC in large-scale, population-based studies. This approach has the advantage over existing filters (e.g., HWE or call rate that it can actually reduce genotyping error rates by automatically correcting some genotyping errors. Applying this LD-based QC procedure to data from The International HapMap Project, we identify over 1,500 SNPs that likely have high error rates in the CHB and JPT samples and estimate corrected genotypes. Our method is implemented in the software package fastPHASE, available from the Stephens Lab website (http://stephenslab.uchicago.edu/software.html.

  2. Construction of black (Rubus occidentalis) and red (R. idaeus) raspberry linkage maps and their comparison to the genomes of strawberry, apple, and peach.

    Science.gov (United States)

    Bushakra, J M; Stephens, M J; Atmadjaja, A N; Lewers, K S; Symonds, V V; Udall, J A; Chagné, D; Buck, E J; Gardiner, S E

    2012-07-01

    The genus Rubus belongs to the Rosaceae and is comprised of 600-800 species distributed world-wide. To date, genetic maps of the genus consist largely of non-transferable markers such as amplified fragment length polymorphisms. An F(1) population developed from a cross between an advanced breeding selection of Rubus occidentalis (96395S1) and R. idaeus 'Latham' was used to construct a new genetic map consisting of DNA sequence-based markers. The genetic linkage maps presented here are constructed of 131 markers on at least one of the two parental maps. The majority of the markers are orthologous, including 14 Rosaceae conserved orthologous set markers, and 60 new gene-based markers developed for raspberry. Thirty-four published raspberry simple sequence repeat markers were used to align the new maps to published raspberry maps. The 96395S1 genetic map consists of six linkage groups (LG) and covers 309 cM with an average of 10 cM between markers; the 'Latham' genetic map consists of seven LG and covers 561 cM with an average of 5 cM between markers. We used BLAST analysis to align the orthologous sequences used to design primer pairs for Rubus genetic mapping with the genome sequences of Fragaria vesca 'Hawaii 4', Malus × domestica 'Golden Delicious', and Prunus 'Lovell'. The alignment of the orthologous markers designed here suggests that the genomes of Rubus and Fragaria have a high degree of synteny and that synteny decreases with phylogenetic distance. Our results give unprecedented insights into the genome evolution of raspberry from the putative ancestral genome of the single ancestor common to Rosaceae.

  3. The genetic population structure of northern Sweden and its implications for mapping genetic diseases.

    Science.gov (United States)

    Einarsdottir, Elisabet; Egerbladh, Inez; Beckman, Lars; Holmberg, Dan; Escher, Stefan A

    2007-11-01

    The northern Swedish population has a history of admixture of three ethnic groups and a dramatic population growth from a relatively small founder population. This has resulted in founder effects that together with unique resources for genealogical analyses provide excellent conditions for genetic mapping of monogenic diseases. Several recent examples of successful mapping of genetic factors underlying susceptibility to complex diseases have suggested that the population of northern Sweden may also be an important tool for efficient mapping of more complex phenotypes. A potential factor contributing to these effects may be population sub-isolates within the large river valleys, constituting a central geographic characteristic of this region. We here provide evidence that marriage patterns as well as the distribution of gene frequencies in a set of marker loci are compatible with this notion. The possible implications of this population structure on linkage- and association based strategies for identifying genes contributing risk to complex diseases are discussed.

  4. Linkage Maps of a Mediterranean × Continental Tall Fescue Population and their Comparative Analysis with Other Poaceae Species

    Directory of Open Access Journals (Sweden)

    Ryan Dierking

    2015-03-01

    Full Text Available Temperate grasses belonging to the complex are important throughout the world in pasture and grassland agriculture. Tall fescue ( Schreb. is the predominant species in the United States, covering approximately 15 million ha. Tall fescue has distinctive morphotypes, two of which are Continental (summer active and Mediterranean (summer semidormant. This is the first report of a linkage map created for Mediterranean tall fescue, while updating the Continental map with additional simple sequence repeat and sequence-tagged site markers. Additionally, this is the first time that diversity arrays technology (DArT markers were used in the construction of a tall fescue map. The male parent (Continental, R43-64, map consisted of 594 markers arranged in 22 linkage groups (LGs and covered a total of 1577 cM. The female parent (Mediterranean, 103-2, map was shorter (1258 cM and consisted of only 208 markers arranged in 29 LGs. Marker densities for R43-64 and 103-2 were 2.65 and 6.08 cM per marker, respectively. When compared with the other Poaceae species, meadow fescue ( Huds., annual ryegrass ( Lam., perennial ryegrass ( L., (L. Beauv., and barley ( L., a total of 171 and 98 orthologous or homologous sequences, identified by DArT analysis, were identified in R43-64 and 103-2, respectively. By using genomic in situ hybridization, we aimed to identify potential progenitors of both morphotypes. However, no clear conclusion on genomic constitution was reached. These maps will aid in the search for quantitative trait loci of various traits as well as help define and distinguish genetic differences between the two morphotypes.

  5. A high-density linkage map of the RN region in pigs.

    Science.gov (United States)

    Looft, C; Milan, D; Jeon, J T; Paul, S; Reinsch, N; Rogel-Gaillard, C; Rey, V; Amarger, V; Robic, A; Kalm, E; Chardon, P; Andersson, L

    2000-01-01

    The porcine RN locus affects muscle glycogen content and meat quality. We previously mapped the RN locus to chromosome 15. This study describes the identification of polymorphisms for four class I and four class II markers located in the RN region. Resource families were genotyped with F-SSCP markers (fluorescent single strand conformation polymorphism) and microsatellite markers. Subsequent multipoint linkage analysis revealed the order FN1-IGFBP5-S1000-S1001-IL8RB-VIL1-RN-Sw936-Sw906. The gene order is identical to the previously reported porcine RH map of the same region. The described map will facilitate positional cloning of the RN gene.

  6. An AFLP-based linkage map of Japanese red pine (Pinus densiflora) using haploid DNA samples of megagametophytes from a single maternal tree.

    Science.gov (United States)

    Kim, Yong-Yul; Choi, Hyung-Soon; Kang, Bum-Yong

    2005-10-31

    We have constructed an AFLP-based linkage map of Japanese red pine (Pinus densiflora Siebold et Zucc.) using haploid DNA samples of 96 megagametophytes from a single maternal tree, selection clone Kyungbuk 4. Twenty-eight primer pairs generated a total of 5,780 AFLP fragments. Five hundreds and thirteen fragments were verified as genetic markers with two alleles by their Mendelian segregation. At the linkage criteria LOD 4.0 and maximum recombination fraction 0.25(theta), a total of 152 markers constituted 25 framework maps for 19 major linkage groups. The maps spanned a total length of 2,341 cM with an average framework marker spacing of 18.4 cM. The estimated genome size was 2,662 cM. With an assumption of equal marker density, 82.2% of the estimated genome would be within 10 cM of one of the 230 linked markers, and 68.1% would be within 10 cM of one of the 152 framework markers. We evaluated map completeness in terms of LOD value, marker density, genome length, and map coverage. The resulting map will provide crucial information for future genomic studies of the Japanese red pine, in particular for QTL mapping of economically important breeding target traits.

  7. Saccharomyces cerevisiae FLO1 Gene Demonstrates Genetic Linkage to Increased Fermentation Rate at Low Temperatures

    Science.gov (United States)

    Deed, Rebecca C.; Fedrizzi, Bruno; Gardner, Richard C.

    2017-01-01

    Low fermentation temperatures are of importance to food and beverage industries working with Saccharomyces cerevisiae. Therefore, the identification of genes demonstrating a positive impact on fermentation kinetics is of significant interest. A set of 121 mapped F1 progeny, derived from a cross between haploid strains BY4716 (a derivative of the laboratory yeast S288C) and wine yeast RM11-1a, were fermented in New Zealand Sauvignon Blanc grape juice at 12.5°. Analyses of five key fermentation kinetic parameters among the F1 progeny identified a quantitative trait locus (QTL) on chromosome I with a significant degree of linkage to maximal fermentation rate (Vmax) at low temperature. Independent deletions of two candidate genes within the region, FLO1 and SWH1, were constructed in the parental strains (with S288C representing BY4716). Fermentation of wild-type and deletion strains at 12.5 and 25° confirmed that the genetic linkage to Vmax corresponds to the S288C version of the FLO1 allele, as the absence of this allele reduced Vmax by ∼50% at 12.5°, but not at 25°. Reciprocal hemizygosity analysis (RHA) between S288C and RM11-1a FLO1 alleles did not confirm the prediction that the S288C version of FLO1 was promoting more rapid fermentation in the opposing strain background, suggesting that the positive effect on Vmax derived from S288C FLO1 may only provide an advantage in haploids, or is dependent on strain-specific cis or trans effects. This research adds to the growing body of evidence demonstrating the role of FLO1 in providing stress tolerance to S. cerevisiae during fermentation. PMID:28143947

  8. Saccharomyces cerevisiae FLO1 Gene Demonstrates Genetic Linkage to Increased Fermentation Rate at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Rebecca C. Deed

    2017-03-01

    Full Text Available Low fermentation temperatures are of importance to food and beverage industries working with Saccharomyces cerevisiae. Therefore, the identification of genes demonstrating a positive impact on fermentation kinetics is of significant interest. A set of 121 mapped F1 progeny, derived from a cross between haploid strains BY4716 (a derivative of the laboratory yeast S288C and wine yeast RM11-1a, were fermented in New Zealand Sauvignon Blanc grape juice at 12.5°. Analyses of five key fermentation kinetic parameters among the F1 progeny identified a quantitative trait locus (QTL on chromosome I with a significant degree of linkage to maximal fermentation rate (Vmax at low temperature. Independent deletions of two candidate genes within the region, FLO1 and SWH1, were constructed in the parental strains (with S288C representing BY4716. Fermentation of wild-type and deletion strains at 12.5 and 25° confirmed that the genetic linkage to Vmax corresponds to the S288C version of the FLO1 allele, as the absence of this allele reduced Vmax by ∼50% at 12.5°, but not at 25°. Reciprocal hemizygosity analysis (RHA between S288C and RM11-1a FLO1 alleles did not confirm the prediction that the S288C version of FLO1 was promoting more rapid fermentation in the opposing strain background, suggesting that the positive effect on Vmax derived from S288C FLO1 may only provide an advantage in haploids, or is dependent on strain-specific cis or trans effects. This research adds to the growing body of evidence demonstrating the role of FLO1 in providing stress tolerance to S. cerevisiae during fermentation.

  9. Whole-genome linkage analysis in mapping alcoholism genes using single-nucleotide polymorphisms and microsatellites.

    Science.gov (United States)

    Wang, Shuang; Huang, Song; Liu, Nianjun; Chen, Liang; Oh, Cheongeun; Zhao, Hongyu

    2005-12-30

    There is currently a great interest in using single-nucleotide polymorphisms (SNPs) in genetic linkage and association studies because of the abundance of SNPs as well as the availability of high-throughput genotyping technologies. In this study, we compared the performance of whole-genome scans using SNPs with microsatellites on 143 pedigrees from the Collaborative Studies on Genetics of Alcoholism provided by Genetic Analysis Workshop 14. A total of 315 microsatellites and 10,081 SNPs from Affymetrix on 22 autosomal chromosomes were used in our analyses. We found that the results from the two scans had good overall concordance. One region on chromosome 2 and two regions on chromosome 7 showed significant linkage signals (i.e., NPL >or= 2) for alcoholism from both the SNP and microsatellite scans. The different results observed between the two scans may be explained by the difference observed in information content between the SNPs and the microsatellites.

  10. [Recent progress in gene mapping through high-throughput sequencing technology and forward genetic approaches].

    Science.gov (United States)

    Lu, Cairui; Zou, Changsong; Song, Guoli

    2015-08-01

    Traditional gene mapping using forward genetic approaches is conducted primarily through construction of a genetic linkage map, the process of which is tedious and time-consuming, and often results in low accuracy of mapping and large mapping intervals. With the rapid development of high-throughput sequencing technology and decreasing cost of sequencing, a variety of simple and quick methods of gene mapping through sequencing have been developed, including direct sequencing of the mutant genome, sequencing of selective mutant DNA pooling, genetic map construction through sequencing of individuals in population, as well as sequencing of transcriptome and partial genome. These methods can be used to identify mutations at the nucleotide level and has been applied in complex genetic background. Recent reports have shown that sequencing mapping could be even done without the reference of genome sequence, hybridization, and genetic linkage information, which made it possible to perform forward genetic study in many non-model species. In this review, we summarized these new technologies and their application in gene mapping.

  11. Perspectives on human genetic variation from the HapMap Project.

    Science.gov (United States)

    McVean, Gil; Spencer, Chris C A; Chaix, Raphaelle

    2005-10-01

    The completion of the International HapMap Project marks the start of a new phase in human genetics. The aim of the project was to provide a resource that facilitates the design of efficient genome-wide association studies, through characterising patterns of genetic variation and linkage disequilibrium in a sample of 270 individuals across four geographical populations. In total, over one million SNPs have been typed across these genomes, providing an unprecedented view of human genetic diversity. In this review we focus on what the HapMap Project has taught us about the structure of human genetic variation and the fundamental molecular and evolutionary processes that shape it.

  12. Identifying plausible genetic models based on association and linkage results: application to type 2 diabetes.

    Science.gov (United States)

    Guan, Weihua; Boehnke, Michael; Pluzhnikov, Anna; Cox, Nancy J; Scott, Laura J

    2012-12-01

    When planning resequencing studies for complex diseases, previous association and linkage studies can constrain the range of plausible genetic models for a given locus. Here, we explore the combinations of causal risk allele frequency (RAFC ) and genotype relative risk (GRRC ) consistent with no or limited evidence for affected sibling pair (ASP) linkage and strong evidence for case-control association. We find that significant evidence for case-control association combined with no or moderate evidence for ASP linkage can define a lower bound for the plausible RAFC . Using data from large type 2 diabetes (T2D) linkage and genome-wide association study meta-analyses, we find that under reasonable model assumptions, 23 of 36 autosomal T2D risk loci are unlikely to be due to causal variants with combined RAFC < 0.005, and four of the 23 are unlikely to be due to causal variants with combined RAFC < 0.05.

  13. A sugar beet (Beta vulgaris L.) reference FISH karyotype for chromosome and chromosome-arm identification, integration of genetic linkage groups and analysis of major repeat family distribution.

    Science.gov (United States)

    Paesold, Susanne; Borchardt, Dietrich; Schmidt, Thomas; Dechyeva, Daryna

    2012-11-01

    We developed a reference karyotype for B. vulgaris which is applicable to all beet cultivars and provides a consistent numbering of chromosomes and genetic linkage groups. Linkage groups of sugar beet were assigned to physical chromosome arms by FISH (fluorescent in situ hybridization) using a set of 18 genetically anchored BAC (bacterial artificial chromosome) markers. Genetic maps of sugar beet were correlated to chromosome arms, and North-South orientation of linkage groups was established. The FISH karyotype provides a technical platform for genome studies and can be applied for numbering and identification of chromosomes in related wild beet species. The discrimination of all nine chromosomes by BAC probes enabled the study of chromosome-specific distribution of the major repetitive components of sugar beet genome comprising pericentromeric, intercalary and subtelomeric satellites and 18S-5.8S-25S and 5S rRNA gene arrays. We developed a multicolor FISH procedure allowing the identification of all nine sugar beet chromosome pairs in a single hybridization using a pool of satellite DNA probes. Fiber-FISH was applied to analyse five chromosome arms in which the furthermost genetic marker of the linkage group was mapped adjacently to terminal repetitive sequences on pachytene chromosomes. Only on two arms telomere arrays and the markers are physically linked, hence these linkage groups can be considered as terminally closed making the further identification of distal informative markers difficult. The results support genetic mapping by marker localization, the anchoring of contigs and scaffolds for the annotation of the sugar beet genome sequence and the analysis of the chromosomal distribution patterns of major families of repetitive DNA.

  14. Linkage mapping in the oilseed cropJatropha curcasL. reveals a locus controlling the biosynthesis of phorbol esters which cause seed toxicity

    OpenAIRE

    2013-01-01

    Current efforts to grow the tropical oilseed crop Jatropha curcas L. economically are hampered by the lack of cultivars and the presence of toxic phorbol esters (PE) within the seeds of most provenances. These PE restrict the conversion of seed cake into animal feed, although naturally occurring ‘nontoxic’ provenances exist which produce seed lacking PE. As an important step towards the development of genetically improved varieties of J. curcas, we constructed a linkage map from four F2 mappi...

  15. Genetic mapping of complex discrete human diseases by discriminant analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The objective of the present study is to propose and evaluate a novel multivariate approach for genetic mapping of complex categorical diseases. This approach results from an application of standard stepwise discriminant analysis to detect linkage based on the differential marker identity-by-descent (IBD) distributions among the different groups of sib pairs. Two major advantages of this method are that it allows for simultaneously testing all markers, together with other genetic and environmental factors in a single multivariate setting and it avoids explicitly modeling the complex relationship between the affection status of sib pairs and the underlying genetic determinants. The efficiency and properties of the method are demonstrated via simulations. The proposed multivariate approach has successfully located the true position(s) under various genetic scenarios. The more important finding is that using highly densely spaced markers (1~2 cM) leads to only a marginal loss of statistical efficiency of the proposed methods in terms of gene localization and statistical power. These results have well established its utility and advantages as a fine-mapping tool. A unique property of the proposed method is the ability to map multiple linked trait loci to their precise positions due to its sequential nature, as demonstrated via simulations.

  16. A high resolution genetic map anchoring scaffolds of the sequenced watermelon genome.

    Science.gov (United States)

    Ren, Yi; Zhao, Hong; Kou, Qinghe; Jiang, Jiao; Guo, Shaogui; Zhang, Haiying; Hou, Wenju; Zou, Xiaohua; Sun, Honghe; Gong, Guoyi; Levi, Amnon; Xu, Yong

    2012-01-01

    As part of our ongoing efforts to sequence and map the watermelon (Citrullus spp.) genome, we have constructed a high density genetic linkage map. The map positioned 234 watermelon genome sequence scaffolds (an average size of 1.41 Mb) that cover about 330 Mb and account for 93.5% of the 353 Mb of the assembled genomic sequences of the elite Chinese watermelon line 97103 (Citrullus lanatus var. lanatus). The genetic map was constructed using an F(8) population of 103 recombinant inbred lines (RILs). The RILs are derived from a cross between the line 97103 and the United States Plant Introduction (PI) 296341-FR (C. lanatus var. citroides) that contains resistance to fusarium wilt (races 0, 1, and 2). The genetic map consists of eleven linkage groups that include 698 simple sequence repeat (SSR), 219 insertion-deletion (InDel) and 36 structure variation (SV) markers and spans ∼800 cM with a mean marker interval of 0.8 cM. Using fluorescent in situ hybridization (FISH) with 11 BACs that produced chromosome-specifc signals, we have depicted watermelon chromosomes that correspond to the eleven linkage groups constructed in this study. The high resolution genetic map developed here should be a useful platform for the assembly of the watermelon genome, for the development of sequence-based markers used in breeding programs, and for the identification of genes associated with important agricultural traits.

  17. Genetic structure and linkage disequilibrium in landrace populations of barley in Sardinia.

    Science.gov (United States)

    Rodriguez, Monica; Rau, Domenico; O'Sullivan, Donal; Brown, Anthony H D; Papa, Roberto; Attene, Giovanna

    2012-06-01

    Multilocus digenic linkage disequilibria (LD) and their population structure were investigated in eleven landrace populations of barley (Hordeum vulgare ssp. vulgare L.) in Sardinia, using 134 dominant simple-sequence amplified polymorphism markers. The analysis of molecular variance for these markers indicated that the populations were partially differentiated (F(ST) = 0.18), and clustered into three geographic areas. Consistent with this population pattern, STRUCTURE analysis allocated individuals from a bulk of all populations into four genetic groups, and these groups also showed geographic patterns. In agreement with other molecular studies in barley, the general level of LD was low (13% of locus pairs, with P landrace populations, but that epistatic homogenising or diversifying selection was also present. Notably, the variance of the disequilibrium component was relatively high, which implies caution in the pooling of barley lines for association studies. Finally, we compared the analyses of multilocus structure in barley landrace populations with parallel analyses in both composite crosses of barley on the one hand and in natural populations of wild barley on the other. Neither of these serves as suitable mimics of landraces in barley, which require their own study. Overall, the results suggest that these populations can be exploited for LD mapping if population structure is controlled.

  18. A genome-wide screen and linkage mapping for a large pedigree with episodic ataxia.

    Science.gov (United States)

    Cader, M Z; Steckley, J L; Dyment, D A; McLachlan, R S; Ebers, G C

    2005-07-12

    Episodic ataxias are ion channel disorders characterized by attacks of incoordination. The authors performed a genome-wide screen in a large pedigree segregating a novel episodic ataxia and found significant linkage on 1q42 with a multipoint lod score of 3.65. Haplotype analysis and fine mapping yielded a peak 2-point lod score of 4.14 and indicated a 4-cM region on 1q42 that is likely to harbor an episodic ataxia gene.

  19. Inheritance and Linkage Map Positions of Genes Conferring Agromorphological Traits in Lens culinaris Medik.

    Directory of Open Access Journals (Sweden)

    Gopesh C. Saha

    2013-01-01

    Full Text Available Agromorphological traits have immense importance in breeding lentils for higher yield and stability. We studied the genetics and identified map positions of some important agro-morphological traits including days to 50% flowering, plant height, seed diameter, 100 seed weight, cotyledon color, and growth habit in Lens culinaris. Earlier developed RILs for stemphylium blight resistance (ILL-5888 × ILL-6002, contrasted for those agro-morphological traits, were used in our study. Three QTLs for days to 50% flowering were detected with additive and epistatic effects. One QTL for days to 50% flowering, QLG483 (QTL at linkage group 4 at 83 cM position, accounted for an estimated 20.2% of the variation, while QLG124 × QLG1352 and QLG484 × QLG138 accounted for 15.6% and 24.2% of the variation, respectively. Epistatic effects accounted for most of the variation in plant height, but the main effect of one QTL, QLG84, accounted for 15.3%. For seed diameter, three QTLs were detected, and one QTL, QLG482, accounted for 32.6% of the variation. For 100 seed weight, five QTLs were identified with significant additive effects and four with significant interaction effects. The main effect of one QTL, QLG482, also accounted for 17.5% of the variation in seed diameter. QLG482-83 which appears to affect days to 50% flowering, seed diameter, and 100 seed weight is flanked by RAPD markers, UBC 34 and UBC1. Growth habit and cotyledon color are controlled by single genes with prostrate dominant to erect and red cotyledon dominant to yellow. The QTL information presented here will assist in the selection of breeding lines for early maturity, upright growth habit, and improved seed quality.

  20. Genetic Linkage Analysis of the Natural Colored Fiber and Fuzzless Traits in Cotton

    Institute of Scientific and Technical Information of China (English)

    LI Fu-zhen; QIU Xin-mian; WANG Ju-qin; LU Yan-tin; BAO Li-sheng

    2008-01-01

    @@ Genetic linkage relationship of the natural colored fiber and six fuzzless seed germplasms in obsolete backgrounds of Gossypium hirsutum (AD genome) and G.barbadense were analyzed in the past two years.Three lines of natural brown fiber that were controlled by single dominant genes and two lines of green fiber controlled by another single dominant gene.

  1. A Genetic Map for the Only Self-Fertilizing Vertebrate.

    Science.gov (United States)

    Kanamori, Akira; Sugita, Yosuke; Yuasa, Yasufumi; Suzuki, Takamasa; Kawamura, Kouichi; Uno, Yoshinobu; Kamimura, Katsuyasu; Matsuda, Yoichi; Wilson, Catherine A; Amores, Angel; Postlethwait, John H; Suga, Koushirou; Sakakura, Yoshitaka

    2016-04-07

    The mangrove killifish Kryptolebias marmoratus, and its close relative Kryptolebias hermaphroditus, are the only vertebrate species known to reproduce by self-fertilization due to functional ovotestis development. To improve our understanding of their genomes, we constructed a genetic map. First, a single F1 fish was made by artificial fertilization between K. marmoratus and K. hermaphroditus strains. F2 progeny were then obtained by self-fertilization of the F1 fish. We used RAD-seq to query genomic DNAs from the two parental strains, the F1 individual and 49 F2 progeny. Results identified 9904 polymorphic RAD-tags (DNA markers) that mapped to 24 linkage groups, corresponding to the haploid chromosome number of these species. The total length of the map was 1248 cM, indicating that about one recombination occurred for each of the 24 homologous chromosome pairs in each meiosis. Markers were not evenly distributed along the chromosomes: in all chromosomes, many markers (> 8% of the total markers for each chromosome) mapped to chromosome tips. Centromeres suppress recombination, and this uneven distribution is probably due to the species' acrocentric chromosomes. Mapped marker sequences were compared to genomic sequences of medaka and platyfish, the next most closely related species with sequenced genomes that are anchored to genetic maps. Results showed that each mangrove killifish chromosome corresponds to a single chromosome of both platyfish and medaka, suggesting strong conservation of chromosomes over 100 million years of evolution. Our genetic map provides a framework for the K. marmoratus/K. hermaphroditus genome sequence and an important resource for understanding the biology of hermaphroditism.

  2. A Genetic Map for the Only Self-Fertilizing Vertebrate

    Directory of Open Access Journals (Sweden)

    Akira Kanamori

    2016-04-01

    Full Text Available The mangrove killifish Kryptolebias marmoratus, and its close relative Kryptolebias hermaphroditus, are the only vertebrate species known to reproduce by self-fertilization due to functional ovotestis development. To improve our understanding of their genomes, we constructed a genetic map. First, a single F1 fish was made by artificial fertilization between K. marmoratus and K. hermaphroditus strains. F2 progeny were then obtained by self-fertilization of the F1 fish. We used RAD-seq to query genomic DNAs from the two parental strains, the F1 individual and 49 F2 progeny. Results identified 9904 polymorphic RAD-tags (DNA markers that mapped to 24 linkage groups, corresponding to the haploid chromosome number of these species. The total length of the map was 1248 cM, indicating that about one recombination occurred for each of the 24 homologous chromosome pairs in each meiosis. Markers were not evenly distributed along the chromosomes: in all chromosomes, many markers (> 8% of the total markers for each chromosome mapped to chromosome tips. Centromeres suppress recombination, and this uneven distribution is probably due to the species’ acrocentric chromosomes. Mapped marker sequences were compared to genomic sequences of medaka and platyfish, the next most closely related species with sequenced genomes that are anchored to genetic maps. Results showed that each mangrove killifish chromosome corresponds to a single chromosome of both platyfish and medaka, suggesting strong conservation of chromosomes over 100 million years of evolution. Our genetic map provides a framework for the K. marmoratus/K. hermaphroditus genome sequence and an important resource for understanding the biology of hermaphroditism.

  3. Genetic overlap of schizophrenia and bipolar disorder in a high-density linkage survey in the Portuguese Island population.

    Science.gov (United States)

    Fanous, Ayman H; Middleton, Frank A; Gentile, Karen; Amdur, Richard L; Maher, Brion S; Zhao, Zhongming; Sun, Jingchun; Medeiros, Helena; Carvalho, Celia; Ferreira, Susana R; Macedo, Antonio; Knowles, James A; Azevedo, Maria H; Pato, Michele T; Pato, Carlos N

    2012-06-01

    Recent family and genome-wide association studies strongly suggest shared genetic risk factors for schizophrenia (SZ) and bipolar disorder (BP). However, linkage studies have not been used to test for statistically significant genome-wide overlap between them. Forty-seven Portuguese families with sibpairs concordant for SZ, BP, or psychosis (PSY, which includes either SZ or psychotic BP) were genotyped for over 57,000 markers using the Affymetrix 50K Xba SNP array. NPL and Kong and Cox LOD scores were calculated in Merlin for all three phenotypes. Empirical significance was determined using 1,000 gene-dropping simulations. Significance of genome-wide genetic overlap between SZ and BP was determined by the number of simulated BP scans having the same number of loci jointly linked with the real SZ scan, and vice versa. For all three phenotypes, a number of regions previously linked in this sample remained so. For BP, chromosome 1p36 achieved significance (11.54-15.71 MB, LOD = 3.51), whereas it was not even suggestively linked at lower marker densities, as did chromosome 11q14.1 (89.32-90.15 MB, NPL = 4.15). Four chromosomes had loci at which both SZ and BP had NPL ≥ 1.98, which was more than would be expected by chance (empirical P = 0.01 using simulated SZ scans; 0.07 using simulated BP scans), although they did not necessarily meet criteria for suggestive linkage individually. These results suggest that high-density marker maps may provide greater power and precision in linkage studies than lower density maps. They also further support the hypothesis that SZ and BP share at least some risk alleles. Copyright © 2012 Wiley Periodicals, Inc.

  4. Utilizing linkage disequilibrium information from Indian Genome Variation Database for mapping mutations: SCA12 case study

    Indian Academy of Sciences (India)

    Samira Bahl; Ikhlak Ahmed; The Indian Genome Variation Consortium; Mitali Mukerji

    2009-04-01

    Stratification in heterogeneous populations poses an enormous challenge in linkage disequilibrium (LD) based identification of causal loci using surrogate markers. In this study, we demonstrate the enormous potential of endogamous Indian populations for mapping mutations in candidate genes using minimal SNPs, mainly due to larger regions of LD. We show this by a case study of the PPP2R2B gene (∼400 kb) that harbours a CAG repeat, expansion of which has been implicated in spinocerebellar ataxia type 12 (SCA12). Using LD information derived from Indian Genome Variation database (IGVdb) on populations which share similar ethnic and linguistic backgrounds as the SCA12 study population, we could map the causal loci using a minimal set of three SNPs, without the generation of additional basal data from the ethnically matched population. We could also demonstrate transferability of tagSNPs from a related HapMap population for mapping the mutation.

  5. A high-density SNP-based linkage map of the chicken genome reveals sequence features correlated with recombination rate

    NARCIS (Netherlands)

    Groenen, M.A.M.; Wahlberg, O.; Foglio, M.; Cheng, H.H.; Megens, H.J.W.C.; Crooijmans, R.P.M.A.; Besnier, F.; Lathrop, A.; Muir, W.M.; Wong, G.K.; Gut, I.; Andersson, L.

    2009-01-01

    The resolution of the chicken consensus linkage map has been dramatically improved in this study by genotyping 12,945 single nucleotide polymorphisms (SNPs) on three existing mapping populations in chicken: the Wageningen (WU), East Lansing (EL), and Uppsala (UPP) mapping populations. As many as 859

  6. Genetic mapping and genomic selection using recombination breakpoint data.

    Science.gov (United States)

    Xu, Shizhong

    2013-11-01

    The correct models for quantitative trait locus mapping are the ones that simultaneously include all significant genetic effects. Such models are difficult to handle for high marker density. Improving statistical methods for high-dimensional data appears to have reached a plateau. Alternative approaches must be explored to break the bottleneck of genomic data analysis. The fact that all markers are located in a few chromosomes of the genome leads to linkage disequilibrium among markers. This suggests that dimension reduction can also be achieved through data manipulation. High-density markers are used to infer recombination breakpoints, which then facilitate construction of bins. The bins are treated as new synthetic markers. The number of bins is always a manageable number, on the order of a few thousand. Using the bin data of a recombinant inbred line population of rice, we demonstrated genetic mapping, using all bins in a simultaneous manner. To facilitate genomic selection, we developed a method to create user-defined (artificial) bins, in which breakpoints are allowed within bins. Using eight traits of rice, we showed that artificial bin data analysis often improves the predictability compared with natural bin data analysis. Of the eight traits, three showed high predictability, two had intermediate predictability, and two had low predictability. A binary trait with a known gene had predictability near perfect. Genetic mapping using bin data points to a new direction of genomic data analysis.

  7. Polymorphism analysis of microsatellites and construction of linkage map in part regions of four chromosomes in chicken

    Institute of Scientific and Technical Information of China (English)

    WANG Shouzhi; LI Hui; LI Ning; GAO Yu; DU Zhiqiang; GU Zhiliang; WANG Qigui; LI Zhihui; WANG Ying

    2007-01-01

    Based on chicken' consensus map issued in 2000, 17 microsatellites near 4 candidate genes such as IGF2, OBR, GDFS and APOA1 in 4 chromosomes (chromosome 5, 7, 8 and 24) were chosen for polymorphism analysis and construction of linkage map. Combining the technique of PCR and the fluorescent semi-automated detection, genome scanning was performed for 440 chickens, which was derived from China Agricultural University chicken resource families within three generations. The individuals of this resource families were genotyped. The results showed that the number of alleles ranged from 4 to 14; heterozygosity (H) of markers was between 0.3116 and 0.9148. Polymorphic information content (PIC) varied from 0.2672 to 0.8679. Microsatellites along with above-mentioned 4 candidate genes doing as general markers were used to construct linkage map. The spans of 4 linkage maps constructed in the part region of chromosome 5, 7, 8 and 24 were 263.5, 79.9, 206.2 and 104.2 cM, respectively. The order of markers was consistent with that of counterpart of reported consensus map. However, The spans of linkage map were larger than that of consensus map. The constructed linkage maps laid the foundation for mapping quantitative trait loci (QTL) responsible for economically important traits in chicken.

  8. Genetic mapping and QTL analysis of disease resistance traits in peanut population Tifrunner x GT-C20

    Science.gov (United States)

    A genetic map of peanut (Arachis hypogaea L.) with 426 SSR markers was constructed using a population of 162 recombinant inbred lines (RILs) from a cross between ‘Tifrunner’ and ‘GT-C20’. Linkage groups (LGs) were assigned to chromosomes using published peanut reference maps. The total length of the...

  9. An ultra-high-density map as a community resource for discerning the genetic basis of quantitative traits in maize

    Science.gov (United States)

    In this study, we generated a linkage map containing 1,151,856 high quality SNPs between Mo17 and B73, which were verified in the maize intermated B73'×'Mo17 (IBM) Syn10 population. This resource is an excellent complement to existing maize genetic maps available in an online database (iPlant, http:...

  10. Perspectives on human genetic variation from the HapMap Project.

    OpenAIRE

    2005-01-01

    ABSTRACT The completion of the International HapMap Project marks the start of a new phase in human genetics. The aim of the project was to provide a resource that facilitates the design of efficient genome-wide association studies, through characterising patterns of genetic variation and linkage disequilibrium in a sample of 270 individuals across four geographical populations. In total, over one million SNPs have been typed across these genomes, providing an unprecedented view of human gene...

  11. The genetic basis of familial hypercholesterolemia: inheritance, linkage, and mutations

    Directory of Open Access Journals (Sweden)

    Isabel De Castro-Orós

    2010-08-01

    Full Text Available Isabel De Castro-Orós1, Miguel Pocoví2, Fernando Civeira11Lipid Unit and Laboratorio de Investigación Molecular, Hospital Universitario Miguel Servet, Instituto Aragonés de Ciencias de la Salud (I+CS, Zaragoza, Spain; 2Departamento. Bioquímica y Biología Molecular y Celular. Universidad de Zaragoza, Instituto Aragonés de Ciencias de la Salud (I+CS, Zaragoza, Spain and Ciber de Enfermedades Raras (CIBERER, Instituto de Salud Carlos III, SpainAbstract: Familial hypercholesterolemia (FH is a genetic disorder of lipoprotein metabolism characterized by high plasma concentrations of low-density lipoprotein cholesterol (LDLc, tendon xanthomas, and increased risk of premature coronary heart disease. FH is one of the most common inherited disorders; there are 10,000,000 people with FH worldwide, mainly heterozygotes. The most common FH cause is mutations along the entire gene that encode for LDL receptor (LDLR protein, but it has been also described that mutations in apolipoprotein B (APOB and proprotein convertase subtilisin/kexin type 9 genes produce this phenotype. About 17%–33% of patients with a clinical diagnosis of monogenic hypercholesterolemia do not harbor any genetic cause in the known loci. Because FH has been considered as a public health problem, it is very important for an early diagnosis and treatment. Recent studies have ­demonstrated the influence of the LDLR mutation type in the FH phenotype, associating a more severe clinical phenotype and worse advanced carotid artherosclerosis in patients with null than those with receptor-defective mutations. Since 2004, a molecular FH diagnosis based on a genetic ­diagnostic platform (Lipochip®; Progenika-Biopharma, Derio, Spain has been developed. This analysis completes the adequate clinical diagnosis made by physicians. Our group has recently proposed new FH guidelines with the intention to facilitate the FH diagnosis. The treatment for this disease is based on the benefit of

  12. LD-Spline: Mapping SNPs on genotyping platforms to genomic regions using patterns of linkage disequilibrium

    Directory of Open Access Journals (Sweden)

    Bush William S

    2009-12-01

    Full Text Available Abstract Background Gene-centric analysis tools for genome-wide association study data are being developed both to annotate single locus statistics and to prioritize or group single nucleotide polymorphisms (SNPs prior to analysis. These approaches require knowledge about the relationships between SNPs on a genotyping platform and genes in the human genome. SNPs in the genome can represent broader genomic regions via linkage disequilibrium (LD, and population-specific patterns of LD can be exploited to generate a data-driven map of SNPs to genes. Methods In this study, we implemented LD-Spline, a database routine that defines the genomic boundaries a particular SNP represents using linkage disequilibrium statistics from the International HapMap Project. We compared the LD-Spline haplotype block partitioning approach to that of the four gamete rule and the Gabriel et al. approach using simulated data; in addition, we processed two commonly used genome-wide association study platforms. Results We illustrate that LD-Spline performs comparably to the four-gamete rule and the Gabriel et al. approach; however as a SNP-centric approach LD-Spline has the added benefit of systematically identifying a genomic boundary for each SNP, where the global block partitioning approaches may falter due to sampling variation in LD statistics. Conclusion LD-Spline is an integrated database routine that quickly and effectively defines the genomic region marked by a SNP using linkage disequilibrium, with a SNP-centric block definition algorithm.

  13. High-Resolution Genome-Wide Linkage Mapping Identifies Susceptibility Loci for BMI in the Chinese Population

    DEFF Research Database (Denmark)

    Zhang, Dong Feng; Pang, Zengchang; Li, Shuxia

    2012-01-01

    The genetic loci affecting the commonly used BMI have been intensively investigated using linkage approaches in multiple populations. This study aims at performing the first genome-wide linkage scan on BMI in the Chinese population in mainland China with hypothesis that heterogeneity in genetic...... in western countries. Multiple loci showing suggestive linkage were found on chromosome 1 (lod score 2.38 at 242 cM), chromosome 8 (2.48 at 95 cM), and chromosome 14 (2.2 at 89.4 cM). The strong linkage identified in the Chinese subjects that is consistent with that found in populations of European origin...... could suggest the existence of evolutionarily preserved genetic mechanisms for BMI whereas the multiple suggestive loci could represent genetic effect from gene-environment interaction as a result of population-specific environmental adaptation....

  14. Genetic mapping of telomere-associated sequences in soybean ( Glycine max )

    Institute of Scientific and Technical Information of China (English)

    刘峰; 张德水; 张劲松; 陈受宜

    2001-01-01

    Two telomere-associated sequences (TAS), named STAS8 and STAS10, were cloned from soybean genomic DNA using polymerase chain reaction (PCR) amplification. Southern analysis showed that they were sequences with moderate copy number in soybean genome. Sequence analysis demonstrated that STAS10 had tandemly arrayed con sensus sequences of TTTAGGG and TIAGGG . The mapping of these two TAS was performed with a population of F8 re combinant inbred line using restriction fragment length polymorphisms(RFLP). Seven out of nine polymorphic fragments were mapped to the most distal position of five linkage groups, Dla, F, G2, H and Q of soybean, and the other two loci were closely linked and mapped to two interstitial positions within linkage group D1a. The mapping of TAS in soybean is essential for completeness of a molecular genetic map of soybean.`

  15. An EST-SSR based linkage map for Persea americana Mill. (avocado)

    Science.gov (United States)

    Recent enhancement of the pool of known molecular markers for avocado has allowed the construction of the first moderate density genetic map for this species. Over 300 microsatellite markers have been characterized and 163 of these were used to construct a map from the cross of two Florida cultivar...

  16. Influence of genotyping error in linkage mapping for complex traits – an analytic study

    Directory of Open Access Journals (Sweden)

    van Houwelingen Hans C

    2008-08-01

    Full Text Available Abstract Background Despite the current trend towards large epidemiological studies of unrelated individuals, linkage studies in families are still thoroughly being utilized as tools for disease gene mapping. The use of the single-nucleotide-polymorphisms (SNP array technology in genotyping of family data has the potential to provide more informative linkage data. Nevertheless, SNP array data are not immune to genotyping error which, as has been suggested in the past, could dramatically affect the evidence for linkage especially in selective designs such as affected sib pair (ASP designs. The influence of genotyping error on selective designs for continuous traits has not been assessed yet. Results We use the identity-by-descent (IBD regression-based paradigm for linkage testing to analytically quantify the effect of simple genotyping error models under specific selection schemes for sibling pairs. We show, for example, that in extremely concordant (EC designs, genotyping error leads to decreased power whereas it leads to increased type I error in extremely discordant (ED designs. Perhaps surprisingly, the effect of genotyping error on inference is most severe in designs where selection is least extreme. We suggest a genomic control for genotyping errors via a simple modification of the intercept in the regression for linkage. Conclusion This study extends earlier findings: genotyping error can substantially affect type I error and power in selective designs for continuous traits. Designs involving both EC and ED sib pairs are fairly immune to genotyping error. When those designs are not feasible the simple genomic control strategy that we suggest offers the potential to deliver more robust inference, especially if genotyping is carried out by SNP array technology.

  17. Definition of arthritis candidate risk genes by combining rat linkage-mapping results with human case-control association data.

    Science.gov (United States)

    Bäckdahl, L; Guo, J P; Jagodic, M; Becanovic, K; Ding, B; Olsson, T; Lorentzen, J C

    2009-12-01

    To define genomic regions that link to rat arthritis and to determine the potential association with rheumatoid arthritis (RA) of the corresponding human genomic regions. Advanced intercross lines (AIL) between arthritis susceptible DA rats and arthritis resistant PVG.1AV1 rats were injected with differently arthritogenic oils to achieve an experimental situation with substantial phenotypic variation in the rat study population. Genotyping of microsatellite markers was performed over genomic regions with documented impact on arthritis, located on rat chromosomes 4, 10 and 12. Linkage between genotypes and phenotypes were determined by R/quantitative trait loci (QTL). Potential association with RA of single nucleotide polymorphisms (SNPs) in homologous human chromosome regions was evaluated from public Wellcome Trust Case Control Consortium (WTCCC) data derived from 2000 cases and 3000 controls. A high frequency of arthritis (57%) was recorded in 422 rats injected with pristane. Maximum linkage to pristane-induced arthritis occurred less than 130 kb from the known genetic arthritis determinants Ncf1 and APLEC, demonstrating remarkable mapping precision. Five novel quantitative trait loci were mapped on rat chromosomes 4 and 10, with narrow confidence intervals. Some exerted sex-biased effects and some were linked to chronic arthritis. Human homologous genomic regions contain loci where multiple nearby SNPs associate nominally with RA (eg, at the genes encoding protein kinase Calpha and interleukin 17 receptor alpha). High-resolution mapping in AIL populations defines limited sets of candidate risk genes, some of which appear also to associate with RA and thus may give clues to evolutionarily conserved pathways that lead to arthritis.

  18. Genetic map of triticale compiling DArT, SSR, and AFLP markers.

    Science.gov (United States)

    Tyrka, M; Bednarek, P T; Kilian, A; Wędzony, M; Hura, T; Bauer, E

    2011-05-01

    A set of 90 doubled haploid (DH) lines derived from F(1) plants that originated from a cross between × Triticosecale Wittm. 'Saka3006' and ×Triticosecale Wittm. 'Modus', via wide crossing with maize, were used to create a genetic linkage map of triticale. The map has 21 linkage groups assigned to the A, B, and R genomes including 155 simple sequence repeat (SSR), 1385 diversity array technology (DArT), and 28 amplified fragment length polymorphism (AFLP) markers covering 2397 cM with a mean distance between two markers of 4.1 cM. Comparative analysis with wheat consensus maps revealed that triticale chromosomes of the A and B genomes were represented by 15 chromosomes, including combinations of 2AS.2AL#, 2AL#2BL, 6AS.6AL#, and 2BS.6AL# instead of 2A, 2B, and 6A. In respect to published maps of rye, substantial rearrangements were found also for chromosomes 1R, 2R, and 3R of the rye genome. Chromosomes 1R and 2R were truncated and the latter was linked with 3R. A nonhomogeneous distribution of markers across the triticale genome was observed with evident bias (48%) towards the rye genome. This genetic map may serve as a reference linkage map of triticale for efficient studies of structural rearrangements, gene mapping, and marker-assisted selection.

  19. Linkage disequilibrium and population-structure analysis among Capsicum annuum L. cultivars for use in association mapping.

    Science.gov (United States)

    Nimmakayala, Padma; Abburi, Venkata L; Abburi, Lavanya; Alaparthi, Suresh Babu; Cantrell, Robert; Park, Minkyu; Choi, Doil; Hankins, Gerald; Malkaram, Sridhar; Reddy, Umesh K

    2014-08-01

    Knowledge of population structure and linkage disequilibrium among the worldwide collections of peppers currently classified as hot, mild, sweet and ornamental types is indispensable for applying association mapping and genomic selection to improve pepper. The current study aimed to resolve the genetic diversity and relatedness of Capsicum annuum germplasm by use of simple sequence repeat (SSR) loci across all chromosomes in samples collected in 2011 and 2012. The physical distance covered by the entire set of SSRs used was 2,265.9 Mb from the 3.48-Gb hot-pepper genome size. The model-based program STRUCTURE was used to infer five clusters, which was further confirmed by classical molecular-genetic diversity analysis. Mean heterozygosity of various loci was estimated to be 0.15. Linkage disequilibrium (LD) was used to identify 17 LD blocks across various chromosomes with sizes from 0.154 Kb to 126.28 Mb. CAMS-142 of chromosome 1 was significantly associated with both capsaicin (CA) and dihydrocapsaicin (DCA) levels. Further, CAMS-142 was located in an LD block of 98.18 Mb. CAMS-142 amplified bands of 244, 268, 283 and 326 bp. Alleles 268 and 283 bp had positive effects on both CA and DCA levels, with an average R(2) of 12.15 % (CA) and 12.3 % (DCA). Eight markers from seven different chromosomes were significantly associated with fruit weight, contributing an average effect of 15 %. CAMS-199, HpmsE082 and CAMS-190 are the three major quantitative trait loci located on chromosomes 8, 9, and 10, respectively, and were associated with fruit weight in samples from both years of the study. This research demonstrates the effectiveness of using genome-wide SSR-based markers to assess features of LD and genetic diversity within C. annuum.

  20. Linkage analysis of five Chinese families with arrhythmogenic right ventricular cardiomyopathy using microsatellite genetic markers

    Institute of Scientific and Technical Information of China (English)

    黄峻; 杨春梅; 马立隽; 单其俊; 许迪; 华子春; 曹克将

    2003-01-01

    Objective To explore the linkage relationship between specific genetic markers and arrhythmogenic right ventricular cardiomyopathy (ARVC) in Chinese pedigrees.Methods The microsatellite genetic markers D2S152, D14S252, and D10S1664 were studied for their linkages to ARVC in five Chinese ARVC pedigrees and a normal population of 121 Chinese individuals. Genomic DNA of the pedigrees and normal population was amplified using PCR techniques. Denaturing polyacrylamide sequencing gel (4%) electrophoresis was used to detect microsatellite repeat polymorphisms. Gels were silver-stained. A classical linkage analysis program was used assuming models of autosomal dominance and recession. Results The logarithm of the odds (LOD) scores of D2S152 with ARVC in LW, WD, DS, LC and TY pedigrees were 2.174, -0.589, -∞, - (indicating that linkage is not supported in this mode), and -∞ respectively in autosomal dominant model (recombination fraction=0.000 respectively)and were -∞, -∞, -∞, -∞, and 0.182 respectively in the autosomal recessive model. The LOD scores of D14S252 with ARVC in LW, WD, DS, LC and TY pedigrees were -, -, -∞, -, and 0 respectively in autosomal dominant model, and were -∞, -0.812, -∞, -∞, and 0.087 respectively in autosomal recessive model. The LOD scores of D2S152 with ARVC in LW, WD, DS, LC and TY pedigrees were -, -0.539, -, and 0.602 respectively in autosomal dominant model and were -, -∞, -∞, -∞, and -∞ respectively in autosomal recessive model. Conclusions The LOD score for D2S152 in the LW pedigree was 2.174, indicating that the chance of linkage is about 150∶ 1. This suggests that there is a possible ARVC-related gene near this marker. There were no clear linkage relationships between ARVC and D10S1664 and D14S252 in this family, and no linkages between ARVC and any of the three genetic markers in the other four families. These results also suggest that there is genetic heterogeneity in LW and in the other pedigrees.

  1. A high-density linkage map of the RN region in pigs

    Directory of Open Access Journals (Sweden)

    Chardon Patrick

    2000-05-01

    Full Text Available Abstract The porcine RN locus affects muscle glycogen content and meat quality. We previously mapped the RN locus to chromosome 15. This study describes the identification of polymorphisms for four class I and four class II markers located in the RN region. Resource families were genotyped with F-SSCP markers (fluorescent single strand conformation polymorphism and microsatellite markers. Subsequent multipoint linkage analysis revealed the order FN1-IGFBP5-S1000-S1001-IL8RB-VIL1-RN-Sw936-Sw906. The gene order is identical to the previously reported porcine RH map of the same region. The described map will facilitate positional cloning of the RN gene.

  2. Examination of X chromosome markers in Rett syndrome: Exclusion mapping with a novel variation on multilocus linkage analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, K.A.; Fill, C.P. (Baylor College of Medicine, Houston, TX (United States)); Terwililger, J.; Percy, A.K.; Zobhbi, H. (Columbia University, NY (United States)); DeGennaro, L.J.; Ott, J. (University of Massachusetts Medical School, Worcester (United States)); Anvret, M.; Martin-Gallardo, A. (National Institutes of Health, Bethesda, MD (United States))

    1992-02-01

    Rett syndrome is a neurologic disorder characterized by early normal development followed by regression, acquired deceleration of head growth, autism, ataxia, and sterotypic hand movements. The exclusive occurrence of the syndrome in females and the occurrence of a few familial cases with inheritance through maternal lines suggest that this disorder is most likely secondary to a mutation on the X chromosome. To address this hypothesis and to identify candidate regions for the Rett syndrome gene locus, genotypic analysis was performed in two families with maternally related affected half-sisters by using 63 DNA markers from the X chromosome. Nineteen of the loci studied were chosen for multipoint linkage analysis because they have been previously genetically mapped using a large number of meioses from reference families. Using the exclusion criterion of a lod score less than [minus]2, the authors were able to exclude the region between the Duchenne muscular dystrophy locus and the DXS456 locus. This region extends from Xp21.2 to Xq21-q23. The use of the multipoint linkage analysis approach outlined in this study should allow the exclusion of additional regions of the X chromosome as new markers are analyzed.

  3. On the Consequences of Purging and Linkage on Fitness and Genetic Diversity

    Directory of Open Access Journals (Sweden)

    Diego Bersabé

    2016-01-01

    Full Text Available Using computer simulation we explore the consequences of linkage on the inbreeding load of an equilibrium population, and on the efficiency of purging and the loss of genetic diversity after a reduction in population size. We find that linkage tends to cause increased inbreeding load due to the build up of coupling groups of (partially recessive deleterious alleles. It also induces associative overdominance at neutral sites but rarely causes increased neutral genetic diversity in equilibrium populations. After a reduction in population size, linkage can cause some delay both for the expression of the inbreeding load and the corresponding purging. However, reasonable predictions can be obtained for the evolution of fitness under inbreeding and purging by using empirical estimates of the inbreeding depression rate. Purging selection against homozygotes for deleterious alleles affects the population’s pedigree. Furthermore, it can slow the loss of genetic diversity compared to that expected from the variance of gametic contributions to the breeding group and even from pedigree inbreeding. Under some conditions, this can lead to a smaller loss of genetic diversity, even below that expected from population size in the absence of selection.

  4. Identification of quantitative trait locus (QTL) linked to dorsal fin length from preliminary linkage map of molly fish, Poecilia sp.

    Science.gov (United States)

    Keong, Bun Poh; Siraj, Siti Shapor; Daud, Siti Khalijah; Panandam, Jothi Malar; Rahman, Arina Nadia Abdul

    2014-02-15

    A preliminary linkage map was constructed by applying backcross and testcross strategy using microsatellite (SSR) markers developed for Xiphophorus and Poecilia reticulata in ornamental fish, molly Poecilia sp. The linkage map having 18 SSR loci consisted of four linkage groups that spanned a map size of 516.1cM. Association between genotypes and phenotypes was tested in a random fashion and QTL for dorsal fin length was found to be linked to locus Msb069 on linkage group 2. Coincidentally, locus Msb069 was also reported as putative homologue primer pairs containing SSRs repeat motif which encoded hSMP-1, a sex determining locus. Dorsal fin length particularly in males of Poecilia latipinna is an important feature during courtship display. Therefore, we speculate that both dorsal fin length and putative hSMP-1 gene formed a close proximity to male sexual characteristics.

  5. Genetic mapping of resistance factors to Phytophthora palmivora in cocoa.

    Science.gov (United States)

    Flament, M H; Kebe, I; Clément, D; Pieretti, I; Risterucci, A M; N'Goran, J A; Cilas, C; Despréaux, D; Lanaud, C

    2001-02-01

    Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in C te d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.

  6. Construction of molecular genetic linkage map based on a rice RIL population and detection of QTL for tiller angle%水稻重组自交系分子遗传图谱构建及分蘖角的QTL检测

    Institute of Scientific and Technical Information of China (English)

    董少玲; 王才林; 张颖慧; 张亚东; 陈涛; 赵庆勇; 朱镇; 周丽慧; 姚姝; 赵凌

    2012-01-01

    利用株型差异显著的特大粒粳稻品系TD70和籼稻小粒品种Kasalath为亲本配制组合,以单粒传方法构建含240个株系的重组自交系( RIL)群体.选用838对SSR引物进行亲本多态性筛选,共检测到302对具有多态性的引物,频率为36.04%.从中选择带型清晰且在基因组中均匀分布的141个SSR标记对RIL群体进行基因型分析,结果表明:群体中父母本基因频率分别为53%和47%,群体结构平衡性好.构建的水稻分子连锁图谱共包含141个标记座位,总图距约1 832.47 cM,标记间平均图距为12.7 cM,标记间图距范围为0.43 ~36.11 cM,符合QTL作图的基本要求.除第1、第8染色体个别标记位置外,其他染色体上标记顺序和位置与已公布的日本晴遗传图谱序列基本一致.以该群体为材料,对分蘖角度进行了QTL检测,共检测到控制分蘖角度的3个QTL位点,分别是qTA8、qTA9和qTA11,贡献率分别为4.10%、26.08%和4.35%,其中qTA9包含控制水稻分蘖角度基因TACI.该图谱的构建为研究籼粳交后代各种性状的遗传规律及QTL定位打下了基础.%In this study, 240 RILs (recombination inbred lines) were developed by single-seed-descent method (SSD) from a cross between Kasalath (Indka) with small grains and TD70 (Japanica) with large grains as parents, which had significant differences in plant type traits, and were used to construct a molecular linkage map. Totally 302 polymorphic SSR (simple sequence repeat) markers were detected, accounting for 36. 04% of the total markers. 141 SSR markers with clear band type and distributing uniformly in the genome were finally used to genotype analysis in a population of 240 lines. Frequencies of male and female genotype in this RIL population respectively were 53% and 47% , indicating the good balance in population structure. A genetic linkage map constructed by 141 markers based on the RIL population spanned 1 832.47 cM length covering all 12

  7. Genetic linkage studies in non-epidermolytic palmoplantar keratoderma: evidence for heterogeneity.

    Science.gov (United States)

    Kelsell, D P; Stevens, H P; Ratnavel, R; Bryant, S P; Bishop, D T; Leigh, I M; Spurr, N K

    1995-06-01

    The palmoplantar keratodermas (PPK) are a group of skin diseases characterized by thickening of the skin of the palms and soles due to abnormal keratinization. We have performed linkage analysis on families affected with three distinct forms of non-epidermolytic PPK (NEPPK): focal, diffuse and punctate. Genetic heterogeneity was demonstrated, with focal NEPPK linked to the region on chromosome 17 harbouring the type I keratin cluster, diffuse NEPPK linked to the region on chromosome 12 containing the type II keratin cluster, and in the punctate NEPPK pedigrees, linkage was excluded to both of these keratin clusters. This study provides evidence for genetic differences between these forms of NEPPK and also between NEPPK and epidermolytic PPK (EPPK) in which mutations in keratin 9 have been demonstrated.

  8. Tight genetic linkage of prezygotic barrier loci creates a multifunctional speciation island in Petunia.

    Science.gov (United States)

    Hermann, Katrin; Klahre, Ulrich; Moser, Michel; Sheehan, Hester; Mandel, Therese; Kuhlemeier, Cris

    2013-05-20

    Most flowering plants depend on animal vectors for pollination and seed dispersal. Differential pollinator preferences lead to premating isolation and thus reduced gene flow between interbreeding plant populations. Sets of floral traits, adapted to attract specific pollinator guilds, are called pollination syndromes. Shifts in pollination syndromes have occurred surprisingly frequently, considering that they must involve coordinated changes in multiple genes affecting multiple floral traits. Although the identification of individual genes specifying single pollination syndrome traits is in progress in many species, little is known about the genetic architecture of coadapted pollination syndrome traits and how they are embedded within the genome. Here we describe the tight genetic linkage of loci specifying five major pollination syndrome traits in the genus Petunia: visible color, UV absorption, floral scent production, pistil length, and stamen length. Comparison with other Solanaceae indicates that, in P. exserta and P. axillaris, loci specifying these floral traits have specifically become clustered into a multifunctional "speciation island". Such an arrangement promotes linkage disequilibrium and avoids the dissolution of pollination syndromes by recombination. We suggest that tight genetic linkage provides a mechanism for rapid switches between distinct pollination syndromes in response to changes in pollinator availabilities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. The genetics of colored sequence synesthesia: Suggestive evidence of linkage to 16q and genetic heterogeneity for the condition

    Science.gov (United States)

    Tomson, Steffie N.; Avidan, Nili; Lee, Kwanghyuk; Sarma, Anand K.; Tushe, Rejnal; Milewicz, Dianna M.; Bray, Molly; Leal, Suzanne M.; Eagleman, David M.

    2014-01-01

    Synesthesia is a perceptual condition in which sensory stimulation triggers anomalous sensory experiences. In colored sequence synesthesia (CSS), color experiences are triggered by sequences such as letters or numbers. We performed a family based linkage analysis to identify genetic loci responsible for the increased neural crosstalk underlying CSS. Our results implicate a 23 MB region at 16q12.2-23.1, providing the first step in understanding the molecular basis of CSS. PMID:21504763

  10. Comparison of molecular linkage maps and QTLs for morphological traits in two reciprocal backcross populations of rice.

    Science.gov (United States)

    Qiao, Yongli; Jiang, Wenzhu; Rahman, Md Lutfor; Chu, Sang-Ho; Piao, Rihua; Han, Longzhi; Koh, Hee-Jong

    2008-05-31

    Comparison of maps and QTLs between populations may provide us with a better understanding of molecular maps and the inheritance of traits. We developed and used two reciprocal BC1F1 populations, IP/DS//IP and IP/DS//DS, for QTL analysis. DS (Dasanbyeo) is a Korean tongil-type cultivar (derived from an indica x japonica cross and similar to indica in its genetic make-up) and IP (Ilpumbyeo) is a Korean japonica cultivar. We constructed two molecular linkage maps corresponding to each backcross population using 196 markers for each map. The length of each chromosome was longer in the IP/DS//IP population than in the IP/DS//DS population, indicating that more recombinants were produced in the IP/DS//IP population. Distorted segregation was observed for 44 and 19 marker loci for the IP/DS//IP and IP/DS//DS populations, respectively; these were mostly skewed in favor of the indica alleles. A total of 36 main effect QTLs (M-QTLs) and 15 digenic epistatic interactions (E-QTLs) were detected for the seven traits investigated. The phenotypic variation explained (PVE) by M-QTLs ranged from 3.4% to 88.2%. Total PVE of the M-QTLs for each trait was significantly higher than that of the E-QTLs. The total number of M-QTLs identified in the IP/DS//IP population was higher than in the IP/DS//DS population. However, the total PVE by the M-QTLs and E-QTLs together for each trait was similar in the two populations, suggesting that the two BC1F1 populations are equally useful for QTL analysis. Maps and QTLs in the two populations were compared. Eleven new QTLs were identified for SN, SF, GL, and GW in this study, and they will be valuable in marker-assisted selection, particularly for improving grain traits in tongil-type varieties.

  11. Global similarity with local differences in linkage disequilibrium between the Dutch and HapMap-CEU populations

    NARCIS (Netherlands)

    Pardo, Luba; Bochdanovits, Zoltan; de Geus, Eco; Hottenga, Jouke J.; Sullivan, Patrick; Posthuma, Danielle; Penninx, Brenda W. J. H.; Boomsma, Dorret; Heutink, Peter

    2009-01-01

    The HapMap project has facilitated the selection of tagging single nucleotide polymorphisms (tagSNPs) for genome-wide association studies (GWAS) under the assumption that linkage disequilibrium (LD) in the HapMap populations is similar to the populations under investigation. Earlier reports support

  12. A High-Density Genetic Map for Cucumber (Cucumis Sativus L. Based on Specific Length Amplified Fragment (SLAF Sequencing and QTL Analysis of Fruit Traits in Cucumber

    Directory of Open Access Journals (Sweden)

    Wenying eZhu

    2016-04-01

    Full Text Available High-density genetic linkage map plays an important role in genome assembly and QTL fine mapping. Since the coming of next-generation sequencing (NGS, makes the structure of high-density linkage maps much more convenient and practical, which simplifies SNP discovery and high-throughput genotyping. In this research, a high-density linkage map of cucumber was structured using specific length amplified fragment sequencing, using 153 F2 populations of S1000×S1002. The high-density genetic map composed 3,057 SLAFs, including 4,475 SNP markers on 7 chromosomes, and spanned 1061.19cM. The average genetic distance is 0.35cM. Based on this high-density genome map, QTL analysis was performed on two cucumber fruit traits, fruit length and fruit diameter. There are 15 QTLs for the two fruit traits were detected.

  13. Quantitative genetics theory for non-inbred populations in linkage disequilibrium

    Directory of Open Access Journals (Sweden)

    José Marcelo Soriano Viana

    2004-01-01

    Full Text Available Although linkage disequilibrium, epistasis and inbreeding are common phenomena in genetic systems that control quantitative traits, theory development and analysis are very complex, especially when they are considered together. The objective of this study is to offer additional quantitative genetics theory to define and analyze, in relation to non-inbred cross pollinating populations, components of genotypic variance, heritabilities and predicted gains, assuming linkage disequilibrium and absence of epistasis. The genotypic variance and its components, additive and due to dominance genetic variances, are invariant over the generations only in regard to completely linked genes and to those in equilibrium. When the population is structured in half-sib families, the additive variance in the parents' generation and the genotypic variance in the population can be estimated. When the population is structured in full-sib families, none of the components of genotypic variance can be estimated. The narrow sense heritability level at plant level can be estimated from the parent-offspring or mid parent-offspring regression. When there is dominance, the narrow sense heritability estimate in the in F2 is biased due to linkage disequilibrium when estimated by the Warner method, but not when estimated by means of the plant F2-family F3 regression. The bias is proportional to the number of pairs of linked genes, without independent assortment, and to the degree of dominance, and tends to be positive when genes in the coupling phase predominate or negative and of higher value when genes in the repulsion phase predominate. Linkage disequilibrium is also cause of bias in estimates of the narrow sense heritabilities at full-sib family mean and at plant within half-sib and full-sib families levels. Generally, the magnitude of the bias is proportional to the number of pairs of genes in disequilibrium and to the frequency of recombining gametes.

  14. Short communication. An improved intersubspecific genetic map in Lens including functional markers

    Directory of Open Access Journals (Sweden)

    R. de la Puente

    2012-12-01

    Full Text Available A previous Lens genetic map was improved by adding 31 molecular genetic markers, reaching a total of 190 markers with undistorted segregation. Data were obtained from the segregational analysis of 113 F2 plants generated from a single hybrid of Lens culinaris ssp. culinaris × L. c. ssp. orientalis. The added markers are predominantly codominant (15 SSRs, five CAPSs, four presence-absence polymorphisms, three length polymorphisms, two RAPDs, and two SRAPs. At a LOD score of 3.0, the 190 markers were grouped into eight linkage groups (LG covering 2,234.4 cM, with an average distance between markers of 12.28 cM. This linkage map has reduced the numbers of linkage groups from ten in the previous map to eight. Most of the added markers must be functional markers since primers were mostly designed to amplify transcribed sequences. Some of the amplicons were sequenced to test if they were functional markers. One of the sequences showed homology with the Pisum TFL1a gene, involved in the transition from vegetative to flowering stages. This lentil gene was located in the LG 1 thanks to the presence of a polymorphic microsatellite in the first intron of the gene. Since L. culinaris ssp. orientalis is the primary source of additional genetic variability for lentil, this improved map could help in the use of such variability in lentil breeding programs.

  15. A comprehensive expressed sequence tag linkage map for tiger salamander and Mexican axolotl: enabling gene mapping and comparative genomics in Ambystoma.

    Science.gov (United States)

    Smith, J J; Kump, D K; Walker, J A; Parichy, D M; Voss, S R

    2005-11-01

    Expressed sequence tag (EST) markers were developed for Ambystoma tigrinum tigrinum (Eastern tiger salamander) and for A. mexicanum (Mexican axolotl) to generate the first comprehensive linkage map for these model amphibians. We identified 14 large linkage groups (125.5-836.7 cM) that presumably correspond to the 14 haploid chromosomes in the Ambystoma genome. The extent of genome coverage for these linkage groups is apparently high because the total map size (5251 cM) falls within the range of theoretical estimates and is consistent with independent empirical estimates. Unlike most vertebrate species, linkage map size in Ambystoma is not strongly correlated with chromosome arm number. Presumably, the large physical genome size ( approximately 30 Gbp) is a major determinant of map size in Ambystoma. To demonstrate the utility of this resource, we mapped the position of two historically significant A. mexicanum mutants, white and melanoid, and also met, a quantitative trait locus (QTL) that contributes to variation in metamorphic timing. This new collection of EST-based PCR markers will better enable the Ambystoma system by facilitating development of new molecular probes, and the linkage map will allow comparative studies of this important vertebrate group.

  16. A genomic perspective on protein tyrosine phosphatases: gene structure, pseudogenes, and genetic disease linkage

    DEFF Research Database (Denmark)

    Andersen, Jannik N; Jansen, Peter G; Echwald, Søren M;

    2004-01-01

    and provide predicted amino acid sequences for four human PTPs that are currently defined by fragments only. Finally, we correlated each PTP locus with genetic disease markers and identified 4 PTPs that map to known susceptibility loci for type 2 diabetes and 19 PTPs that map to regions frequently deleted...

  17. Linkage disequilibrium mapping identifies a 390 kb region associated with CYP2D6 poor drug metabolising activity.

    Science.gov (United States)

    Hosking, L K; Boyd, P R; Xu, C F; Nissum, M; Cantone, K; Purvis, I J; Khakhar, R; Barnes, M R; Liberwirth, U; Hagen-Mann, K; Ehm, M G; Riley, J H

    2002-01-01

    The cytochrome p450 enzyme, CYP2D6, metabolises approximately 20% of marketed drugs. CYP2D6 multiple variants are associated with altered enzyme activities. Genotyping 1018 Caucasians for CYP2D6 polymorphisms (G1846A, delT1707, delA2549 and A2935C), known to result in the recessive CYP2D6 poor drug metaboliser (PM) phenotype, identified 41 individuals with predicted PM phenotype. These 41 individuals were classified as 'cases'. Single nucleotide polymorphisms (SNPs) mapping within an 880 kb region flanking CYP2D6, were identified to evaluate potential association between genetic variation and the CYP2D6 PM phenotype. The 41 PM cases and 977 controls were genotyped and analysed for 27 SNPs. Associations were observed across a 390 kb region between 14 SNPs and the PM phenotype (P values from 6.20 x 10(-4) to 4.54 x 10(-35)). Haplotype analysis revealed more significant levels of association (P = 3.54 x 10(-56)). Strong (D' > 0.7) linkage disequilibrium (LD) between SNPs was observed across the same 390 kb region associated with the CYP2D6 phenotype. The observed phenotype:genotype association reached genome-wide levels of significance, and supports the strategy for potential application of LD mapping and whole genome association scans to pharmacogenetic studies.

  18. Reconstruction of linkage maps in the distorted segregation populations of backcross,doubled haploid and recombinant inbred lines

    Institute of Scientific and Technical Information of China (English)

    ZHU ChengSong; WANG FuHua; WANG JianFei; LI GuangJun; ZHANG HongSheng; ZHANG YuanMing

    2007-01-01

    Non-Mendelian segregation of markers,known as distorted segregation,is a common biological phenomenon.Although segregation distortion affects the estimation of map distances and the results of quantitative trait loci(QTL)mapping,the effects of distorted markers are often ignored in the construction of linkage maps and in QTL mapping.Recently,we have developed a multipoint method via a Hidden Markov chain method to reconstruct linkage maps in an F2 population that corrects for bias of map distances between distorted markers.In this article,the method is extended to cover backcross,doubled haploid and recombinant inbred line(RIL)populations.The results from simulated experiments show that:(1)the degree that two linked segregation distortion loci(SDL)affect the estimation of map distances increases as SDL heritability and interval length between adjacent markers increase,whereas sample size has little effect on the bias;(2)two linked SDL result in the underestimation of linkage distances for most cases,overestimation for an additive model with opposite additive effects,and unbiased estimation for an epistatic model with negative additive-by-additive effects;(3)the proposed method can obtain the unbiased estimation of linkage distance.This new method was applied to a rice RIL population with severely distorted segregation to reconstruct the linkage maps,and a bootstrap method was used to Obtain 95% confidence intervals of map distances.The results from real data analysis further demonstrate the utility of our method,which provides a foundation for the inheritance analysis of quantitative and viability traits.

  19. Genotyping-by-Sequencing derived High-Density Linkage Map and its Application to QTL Mapping of Flag Leaf Traits in Bread Wheat

    Science.gov (United States)

    Hard red winter wheat parents ‘Harry’ (drought tolerant) and ‘Wesley’ (drought susceptible) was used to develop a recombinant inbred population to identify genomic regions associated with drought and adaptation. To precisely map genomic regions high-density linkage maps are a prerequisite. In this s...

  20. Localisation of morphological traits on the genetic map of potato using RFLP and isozyme markers = [Localisatie van morfologische eigenschappen op de genetische kaart van de aardappel door middel van RFLP en isozym merkers

    NARCIS (Netherlands)

    Eck, van H.J.

    1995-01-01


    The thesis describes the construction of a genetic linkage map of the potato genome, comprising molecular, isozyme and morphological markers. The linkage map is based on the offspring from non-inbred parents. The computer program JOINM

  1. Genetic linkage analysis of familial amyotrophic lateral sclerosis using human chromosome 21 microsatellite DNA markers

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, D.R.; Sapp, P.; O`Regan, J.; McKenna-Yasek, D.; Schlumpf, K.S.; Haines, J.L.; Gusella, J.F.; Horvitz, H.R.; Brown, R.H. Jr. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1994-05-15

    Amyotrophic lateral sclerosis (ALS; Lou Gehrig`s Disease) is a lethal neurodegenerative disease of upper and lower motorneurons in the brain and spinal cord. We previously reported linkage of a gene for familial ALS (FALS) to human chromosome 21 using 4 restriction fragment length polymorphism DNA markers and identified disease-associated mutations in the superoxide dismutase (SOD)-1 gene in some ALS families. We report here the genetic linkage data that led us to examine the SOD-1 gene for mutations. We also report a new microsatellite DNA marker for D21S63, derived from the cosmid PW517. Ten microsatellite DNA markers, including the new marker D21S63, were used to reinvestigate linkage of FALS to chromosome 21. Genetic linkage analysis performed with 13 ALS familes for these 10 DNA markers confirmed the presence of a FALS gene on chromosome 21. The highest total 2-point LOD score for all families was 4.33, obtained at a distance of 10 cM from the marker D21S223. For 5 ALS families linked to chromosome 21, a peak 2-point LOD score of 5.94 was obtained at the DNA marker D21S223. A multipoint score of 6.50 was obtained with the markers D21S213, D21S223, D21S167, and FALS for 5 chromosome 21-linked ALS families. The haplotypes of these families for the 10 DNA markers reveal recombination events that further refined the location of the FALS gene to a segment of approximately 5 megabases (Mb) between D21S213 and D21S219. The only characterized gene within this segment was SOD-1, the structural gene for Cu, Zn SOD. 30 refs., 4 figs., 4 tabs.

  2. Genetic crossovers are predicted accurately by the computed human recombination map.

    Directory of Open Access Journals (Sweden)

    Pavel P Khil

    2010-01-01

    Full Text Available Hotspots of meiotic recombination can change rapidly over time. This instability and the reported high level of inter-individual variation in meiotic recombination puts in question the accuracy of the calculated hotspot map, which is based on the summation of past genetic crossovers. To estimate the accuracy of the computed recombination rate map, we have mapped genetic crossovers to a median resolution of 70 Kb in 10 CEPH pedigrees. We then compared the positions of crossovers with the hotspots computed from HapMap data and performed extensive computer simulations to compare the observed distributions of crossovers with the distributions expected from the calculated recombination rate maps. Here we show that a population-averaged hotspot map computed from linkage disequilibrium data predicts well present-day genetic crossovers. We find that computed hotspot maps accurately estimate both the strength and the position of meiotic hotspots. An in-depth examination of not-predicted crossovers shows that they are preferentially located in regions where hotspots are found in other populations. In summary, we find that by combining several computed population-specific maps we can capture the variation in individual hotspots to generate a hotspot map that can predict almost all present-day genetic crossovers.

  3. Genome-wide evaluation of genetic diversity and linkage disequilibrium in winter and spring triticale (x Triticosecale Wittmack

    Directory of Open Access Journals (Sweden)

    Alheit Katharina V

    2012-06-01

    Full Text Available Abstract Background Recent advances in genotyping with high-density markers nowadays enable genome-wide genomic analyses in crops. A detailed characterisation of the population structure and linkage disequilibrium (LD is essential for the application of genomic approaches and consequently for knowledge-based breeding. In this study we used the triticale-specific DArT array to analyze population structure, genetic diversity, and LD in a worldwide set of 161 winter and spring triticale lines. Results The principal coordinate analysis revealed that the first principal coordinate divides the triticale population into two clusters according to their growth habit. The density distributions of the first ten principal coordinates revealed that several show a distribution indicative of population structure. In addition, we observed relatedness within growth habits which was higher among the spring types than among the winter types. The genome-wide analysis of polymorphic information content (PIC showed that the PIC is variable among and along chromosomes and that especially the R genome of spring types possesses a reduced genetic diversity. We also found that several chromosomes showed regions of high genetic distance between the two growth habits, indicative of divergent selection. Regarding linkage disequilibrium, the A and B genomes showed a similar LD of 0.24 for closely linked markers and a decay within approximately 12 cM. LD in the R genome was lower with 0.19 and decayed within a shorter map distance of approximately 5 cM. The extent of LD was generally higher for the spring types compared to the winter types. In addition, we observed strong variability of LD along the chromosomes. Conclusions Our results confirm winter and spring growth habit are the major contributors to population structure in triticale, and a family structure exists in both growth types. The specific patterns of genetic diversity observed within these types, such as the

  4. Preimplantation genetic diagnosis of X-linked Charcot-Marie-Tooth disease by indirect linkage analysis.

    Science.gov (United States)

    Borgulová, Irena; Putzová, Martina; Soldatova, Inna; Stejskal, David

    2017-08-07

    To present methodical approach of preimplantation genetic diagnosis (PGD) as an option for an unaffected pregnancy in reproductive-age couples who have a genetic risk of the X-linked dominant peripheral neuropathy Charcot-Marie-Tooth type 1 disease. We performed PGD of X-linked Charcot-Marie-Tooth type 1 disease using haplotyping/indirect linkage analysis, when during analysis we reach to exclude embryos that carry a high-risk haplotype linked to the causal mutation p.Leu9Phe in the GJB1 gene. Within the PGD cycle, we examined 4 blastomeres biopsied from cleavage-stage embryos and recommended 3 embryos for transfer. Two embryos were implanted into the uterus; however, it resulted in a singleton pregnancy with a male descendant. Three years later, the couple returned again with spontaneous gravidity. A chorionic biopsy examination of this gravidity ascertained the female sex and a pericentric inversion of chromosome 5 in 70% of the cultivated foetal cells. Using indirect linkage analysis, PGD may help to identify genetic X-linked defects within embryos during screening, thereby circumventing the potential problems with abortion. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  5. Association mapping of insecticide resistance in wild Anopheles gambiae populations: major variants identified in a low-linkage disequilbrium genome.

    Directory of Open Access Journals (Sweden)

    David Weetman

    Full Text Available BACKGROUND: Association studies are a promising way to uncover the genetic basis of complex traits in wild populations. Data on population stratification, linkage disequilibrium and distribution of variant effect-sizes for different trait-types are required to predict study success but are lacking for most taxa. We quantified and investigated the impacts of these key variables in a large-scale association study of a strongly selected trait of medical importance: pyrethroid resistance in the African malaria vector Anopheles gambiae. METHODOLOGY/PRINCIPAL FINDINGS: We genotyped ≈1500 resistance-phenotyped wild mosquitoes from Ghana and Cameroon using a 1536-SNP array enriched for candidate insecticide resistance gene SNPs. Three factors greatly impacted study power. (1 Population stratification, which was attributable to co-occurrence of molecular forms (M and S, and cryptic within-form stratification necessitating both a partitioned analysis and genomic control. (2 All SNPs of substantial effect (odds ratio, OR>2 were rare (minor allele frequency, MAF<0.05. (3 Linkage disequilibrium (LD was very low throughout most of the genome. Nevertheless, locally high LD, consistent with a recent selective sweep, and uniformly high ORs in each subsample facilitated significant direct and indirect detection of the known insecticide target site mutation kdr L1014F (OR≈6; P<10(-6, but with resistance level modified by local haplotypic background. CONCLUSION: Primarily as a result of very low LD in wild A. Gambiae, LD-based association mapping is challenging, but is feasible at least for major effect variants, especially where LD is enhanced by selective sweeps. Such variants will be of greatest importance for predictive diagnostic screening.

  6. Development of a 690 K SNP array in catfish and its application for genetic mapping and validation of the reference genome sequence

    Science.gov (United States)

    Zeng, Qifan; Fu, Qiang; Li, Yun; Waldbieser, Geoff; Bosworth, Brian; Liu, Shikai; Yang, Yujia; Bao, Lisui; Yuan, Zihao; Li, Ning; Liu, Zhanjiang

    2017-01-01

    Single nucleotide polymorphisms (SNPs) are capable of providing the highest level of genome coverage for genomic and genetic analysis because of their abundance and relatively even distribution in the genome. Such a capacity, however, cannot be achieved without an efficient genotyping platform such as SNP arrays. In this work, we developed a high-density SNP array with 690,662 unique SNPs (herein 690 K array) that were relatively evenly distributed across the entire genome, and covered 98.6% of the reference genome sequence. Here we also report linkage mapping using the 690 K array, which allowed mapping of over 250,000 SNPs on the linkage map, the highest marker density among all the constructed linkage maps. These markers were mapped to 29 linkage groups (LGs) with 30,591 unique marker positions. This linkage map anchored 1,602 scaffolds of the reference genome sequence to LGs, accounting for over 97% of the total genome assembly. A total of 1,007 previously unmapped scaffolds were placed to LGs, allowing validation and in few instances correction of the reference genome sequence assembly. This linkage map should serve as a valuable resource for various genetic and genomic analyses, especially for GWAS and QTL mapping for genes associated with economically important traits. PMID:28079141

  7. A Solanum lycopersicum × Solanum pimpinellifolium Linkage Map of Tomato Displaying Genomic Locations of R-Genes, RGAs, and Candidate Resistance/Defense-Response ESTs

    Science.gov (United States)

    Sharma, Arun; Zhang, Liping; Niño-Liu, David; Ashrafi, Hamid; Foolad, Majid R.

    2008-01-01

    We have identified an accession (LA2093) within the tomato wild species Solanum pimpinellifolium with many desirable characteristics, including biotic and abiotic stress tolerance and good fruit quality. To utilize the full genetic potential of LA2093 in tomato breeding, we have developed a linkage map based on an F2 population of a cross between LA2093 and a tomato breeding line, using 115 RFLP, 94 EST, and 41 RGA markers. The map spanned 1002.4 cM of the 12 tomato chromosomes with an average marker distance of 4.0 cM. The length of the map and linear order of the markers were in good agreement with the published maps of tomato. The ESTs were chosen based on their sequence similarities with known resistance or defense-response genes, signal-transduction factors, transcriptional regulators, and genes encoding pathogenesis-related proteins. Locations of several ESTs and RGAs coincided with locations of several known tomato resistance genes and quantitative resistance loci (QRLs), suggesting that candidate-gene approach may be effective in identifying and mapping new R genes. This map will be useful for marker-assisted exploitation of desirable traits in LA2093 and other S. pimpinellifolium accessions, and possibly for utilization of genetic variation within S. lycopersicum. PMID:19223983

  8. Enhanced genetic maps from family-based disease studies: population-specific comparisons

    Directory of Open Access Journals (Sweden)

    Buyske Steven

    2011-01-01

    Full Text Available Abstract Background Accurate genetic maps are required for successful and efficient linkage mapping of disease genes. However, most available genome-wide genetic maps were built using only small collections of pedigrees, and therefore have large sampling errors. A large set of genetic studies genotyped by the NHLBI Mammalian Genotyping Service (MGS provide appropriate data for generating more accurate maps. Results We collected a large sample of uncleaned genotype data for 461 markers generated by the MGS using the Weber screening sets 9 and 10. This collection includes genotypes for over 4,400 pedigrees containing over 17,000 genotyped individuals from different populations. We identified and cleaned numerous relationship and genotyping errors, as well as verified the marker orders. We used this dataset to test for population-specific genetic maps, and to re-estimate the genetic map distances with greater precision; standard errors for all intervals are provided. The map-interval sizes from the European (or European descent, Chinese, and Hispanic samples are in quite good agreement with each other. We found one map interval on chromosome 8p with a statistically significant size difference between the European and Chinese samples, and several map intervals with significant size differences between the African American and Chinese samples. When comparing Palauan with European samples, a statistically significant difference was detected at the telomeric region of chromosome 11p. Several significant differences were also identified between populations in chromosomal and genome lengths. Conclusions Our new population-specific screening set maps can be used to improve the accuracy of disease-mapping studies. As a result of the large sample size, the average length of the 95% confidence interval (CI for a 10 cM map interval is only 2.4 cM, which is considerably smaller than on previously published maps.

  9. Gene-based SNP discovery and genetic mapping in pea.

    Science.gov (United States)

    Sindhu, Anoop; Ramsay, Larissa; Sanderson, Lacey-Anne; Stonehouse, Robert; Li, Rong; Condie, Janet; Shunmugam, Arun S K; Liu, Yong; Jha, Ambuj B; Diapari, Marwan; Burstin, Judith; Aubert, Gregoire; Tar'an, Bunyamin; Bett, Kirstin E; Warkentin, Thomas D; Sharpe, Andrew G

    2014-10-01

    Gene-based SNPs were identified and mapped in pea using five recombinant inbred line populations segregating for traits of agronomic importance. Pea (Pisum sativum L.) is one of the world's oldest domesticated crops and has been a model system in plant biology and genetics since the work of Gregor Mendel. Pea is the second most widely grown pulse crop in the world following common bean. The importance of pea as a food crop is growing due to its combination of moderate protein concentration, slowly digestible starch, high dietary fiber concentration, and its richness in micronutrients; however, pea has lagged behind other major crops in harnessing recent advances in molecular biology, genomics and bioinformatics, partly due to its large genome size with a large proportion of repetitive sequence, and to the relatively limited investment in research in this crop globally. The objective of this research was the development of a genome-wide transcriptome-based pea single-nucleotide polymorphism (SNP) marker platform using next-generation sequencing technology. A total of 1,536 polymorphic SNP loci selected from over 20,000 non-redundant SNPs identified using deep transcriptome sequencing of eight diverse Pisum accessions were used for genotyping in five RIL populations using an Illumina GoldenGate assay. The first high-density pea SNP map defining all seven linkage groups was generated by integrating with previously published anchor markers. Syntenic relationships of this map with the model legume Medicago truncatula and lentil (Lens culinaris Medik.) maps were established. The genic SNP map establishes a foundation for future molecular breeding efforts by enabling both the identification and tracking of introgression of genomic regions harbouring QTLs related to agronomic and seed quality traits.

  10. CMap3D: a 3D visualization tool for comparative genetic maps.

    Science.gov (United States)

    Duran, Chris; Boskovic, Zoran; Imelfort, Michael; Batley, Jacqueline; Hamilton, Nicholas A; Edwards, David

    2010-01-15

    Genetic linkage mapping enables the study of genome organization and the association of heritable traits with regions of sequenced genomes. Comparative genetic mapping is particularly powerful as it allows translation of information between related genomes and gives an insight into genome evolution. A common tool for the storage, comparison and visualization of genetic maps is CMap. However, current visualization in CMap is limited to the comparison of adjacent aligned maps. To overcome this limitation, we have developed CMap3D, a tool to compare multiple genetic maps in three-dimensional space. CMap3D is based on a client/server model ensuring operability with current CMap data repositories. This tool can be applied to any species where genetic map information is available and enables rapid, direct comparison between multiple aligned maps. The software is a stand-alone application written in Processing and Java. Binaries are available for Windows, OSX and Linux, and require Sun Microsystems Java Runtime Environment 1.6 or later. The software is freely available for non-commercial use from http://flora.acpfg.com.au/.

  11. A Microsatellite Genetic Map of the Turbot (Scophthalmus maximus)

    Science.gov (United States)

    Bouza, Carmen; Hermida, Miguel; Pardo, Belén G.; Fernández, Carlos; Fortes, Gloria G.; Castro, Jaime; Sánchez, Laura; Presa, Pablo; Pérez, Montse; Sanjuán, Andrés; de Carlos, Alejandro; Álvarez-Dios, José Antonio; Ezcurra, Susana; Cal, Rosa M.; Piferrer, Francesc; Martínez, Paulino

    2007-01-01

    A consensus microsatellite-based linkage map of the turbot (Scophthalmus maximus) was constructed from two unrelated families. The mapping panel was derived from a gynogenetic family of 96 haploid embryos and a biparental diploid family of 85 full-sib progeny with known linkage phase. A total of 242 microsatellites were mapped in 26 linkage groups, six markers remaining unlinked. The consensus map length was 1343.2 cM, with an average distance between markers of 6.5 ± 0.5 cM. Similar length of female and male maps was evidenced. However, the mean recombination at common intervals throughout the genome revealed significant differences between sexes, ∼1.6 times higher in the female than in the male. The comparison of turbot microsatellite flanking sequences against the Tetraodon nigroviridis genome revealed 55 significant matches, with a mean length of 102 bp and high sequence similarity (81–100%). The comparative mapping revealed significant syntenic regions among fish species. This study represents the first linkage map in the turbot, one of the most important flatfish in European aquaculture. This map will be suitable for QTL identification of productive traits in this species and for further evolutionary studies in fish and vertebrate species. PMID:18073440

  12. Genome-wide linkage mapping of QTL for black point reaction in bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Liu, Jindong; He, Zhonghu; Wu, Ling; Bai, Bin; Wen, Weie; Xie, Chaojie; Xia, Xianchun

    2016-11-01

    Nine QTL for black point resistance in wheat were identified using a RIL population derived from a Linmai 2/Zhong 892 cross and 90K SNP assay. Black point, discoloration of the embryo end of the grain, downgrades wheat grain quality leading to significant economic losses to the wheat industry. The availability of molecular markers will accelerate improvement of black point resistance in wheat breeding. The aims of this study were to identify quantitative trait loci (QTL) for black point resistance and tightly linked molecular markers, and to search for candidate genes using a high-density genetic linkage map of wheat. A recombinant inbred line (RIL) population derived from the cross Linmai 2/Zhong 892 was evaluated for black point reaction during the 2011-2012, 2012-2013 and 2013-2014 cropping seasons, providing data for seven environments. A high-density linkage map was constructed by genotyping the RILs with the wheat 90K single nucleotide polymorphism (SNP) chip. Composite interval mapping detected nine QTL on chromosomes 2AL, 2BL, 3AL, 3BL, 5AS, 6A, 7AL (2) and 7BS, designated as QBp.caas-2AL, QBp.caas-2BL, QBp.caas-3AL, QBp.caas-3BL, QBp.caas-5AS, QBp.caas-6A, QBp.caas-7AL.1, QBp.caas-7AL.2 and QBp.caas-7BS, respectively. All resistance alleles, except for QBp.caas-7AL.1 from Linmai 2, were contributed by Zhong 892. QBp.caas-3BL, QBp.caas-5AS, QBp.caas-7AL.1, QBp.caas-7AL.2 and QBp.caas-7BS probably represent new loci for black point resistance. Sequences of tightly linked SNPs were used to survey wheat and related cereal genomes identifying three candidate genes for black point resistance. The tightly linked SNP markers can be used in marker-assisted breeding in combination with the kompetitive allele specific PCR technique to improve black point resistance.

  13. Genetic Map of Triticale Integrating Microsatellite, DArT and SNP Markers.

    Science.gov (United States)

    Tyrka, Mirosław; Tyrka, Dorota; Wędzony, Maria

    2015-01-01

    Triticale (×Triticosecale Wittm) is an economically important crop for fodder and biomass production. To facilitate the identification of markers for agronomically important traits and for genetic and genomic characteristics of this species, a new high-density genetic linkage map of triticale was constructed using doubled haploid (DH) population derived from a cross between cultivars 'Hewo' and 'Magnat'. The map consists of 1615 bin markers, that represent 50 simple sequence repeat (SSR), 842 diversity array technology (DArT), and 16888 DArTseq markers mapped onto 20 linkage groups assigned to the A, B, and R genomes of triticale. No markers specific to chromosome 7R were found, instead mosaic linkage group composed of 1880 highly distorted markers (116 bins) from 10 wheat chromosomes was identified. The genetic map covers 4907 cM with a mean distance between two bins of 3.0 cM. Comparative analysis in respect to published maps of wheat, rye and triticale revealed possible deletions in chromosomes 4B, 5A, and 6A, as well as inversion in chromosome 7B. The number of bin markers in each chromosome varied from 24 in chromosome 3R to 147 in chromosome 6R. The length of individual chromosomes ranged between 50.7 cM for chromosome 2R and 386.2 cM for chromosome 7B. A total of 512 (31.7%) bin markers showed significant (P triticale will facilitate fine mapping of quantitative trait loci, the identification of candidate genes and map-based cloning.

  14. SNP identification from RNA sequencing and linkage map construction of rubber tree for anchoring the draft genome.

    Directory of Open Access Journals (Sweden)

    Jeremy R Shearman

    Full Text Available Hevea brasiliensis, or rubber tree, is an important crop species that accounts for the majority of natural latex production. The rubber tree nuclear genome consists of 18 chromosomes and is roughly 2.15 Gb. The current rubber tree reference genome assembly consists of 1,150,326 scaffolds ranging from 200 to 531,465 bp and totalling 1.1 Gb. Only 143 scaffolds, totalling 7.6 Mb, have been placed into linkage groups. We have performed RNA-seq on 6 varieties of rubber tree to identify SNPs and InDels and used this information to perform target sequence enrichment and high throughput sequencing to genotype a set of SNPs in 149 rubber tree offspring from a cross between RRIM 600 and RRII 105 rubber tree varieties. We used this information to generate a linkage map allowing for the anchoring of 24,424 contigs from 3,009 scaffolds, totalling 115 Mb or 10.4% of the published sequence, into 18 linkage groups. Each linkage group contains between 319 and 1367 SNPs, or 60 to 194 non-redundant marker positions, and ranges from 156 to 336 cM in length. This linkage map includes 20,143 of the 69,300 predicted genes from rubber tree and will be useful for mapping studies and improving the reference genome assembly.

  15. SNP identification from RNA sequencing and linkage map construction of rubber tree for anchoring the draft genome.

    Science.gov (United States)

    Shearman, Jeremy R; Sangsrakru, Duangjai; Jomchai, Nukoon; Ruang-Areerate, Panthita; Sonthirod, Chutima; Naktang, Chaiwat; Theerawattanasuk, Kanikar; Tragoonrung, Somvong; Tangphatsornruang, Sithichoke

    2015-01-01

    Hevea brasiliensis, or rubber tree, is an important crop species that accounts for the majority of natural latex production. The rubber tree nuclear genome consists of 18 chromosomes and is roughly 2.15 Gb. The current rubber tree reference genome assembly consists of 1,150,326 scaffolds ranging from 200 to 531,465 bp and totalling 1.1 Gb. Only 143 scaffolds, totalling 7.6 Mb, have been placed into linkage groups. We have performed RNA-seq on 6 varieties of rubber tree to identify SNPs and InDels and used this information to perform target sequence enrichment and high throughput sequencing to genotype a set of SNPs in 149 rubber tree offspring from a cross between RRIM 600 and RRII 105 rubber tree varieties. We used this information to generate a linkage map allowing for the anchoring of 24,424 contigs from 3,009 scaffolds, totalling 115 Mb or 10.4% of the published sequence, into 18 linkage groups. Each linkage group contains between 319 and 1367 SNPs, or 60 to 194 non-redundant marker positions, and ranges from 156 to 336 cM in length. This linkage map includes 20,143 of the 69,300 predicted genes from rubber tree and will be useful for mapping studies and improving the reference genome assembly.

  16. Physical and linkage mapping of the human and murine genes for the [alpha]1 chain of type IX collagen (COL9A1)

    Energy Technology Data Exchange (ETDEWEB)

    Warman, M.L. (Harvard Medical School, Boston, MA (United States) Children' s Hospital/Harvard Medical School, Boston, MA (United States)); Tiller, G.E.; Polumbo, P.A. (Vanderbilt Univ. Medical Center, Nashville, TN (United States)); Seldin, M.F.; Rochelle, J.M. (Duke Univ. Medical Center, Durham, NC (United States)); Knoll, J.H.M.; Cheng, Sou De (Children' s Hospital/Harvard Medical School, Boston, MA (United States)); Olsen, B.R. (Harvard Medical School, Boston, MA (United States))

    1993-09-01

    The IX collagen, a member of the FACIT family of extracellular matrix proteins, is a heterotrimer composed of three genetically distinct [alpha] chains. The cDNAs for the human and mouse [alpha]1(IX) chains have been cloned. In this paper the authors confirm the mapping of the human COL9A1 gene to chromosome 6q12-q13 by fluorescence in situ hybridization utilizing two genomic clones which also contain short tandem repeat polymorphisms. They also report the characterization of these repeats and their incorporation into the chromosome 6 linkage map. The COL9A1 locus shows no recombination with the marker D6Z1 (Z = 27.61 at [theta] = 0) and identifies the most likely locus order of KRAS1P-[D6Z1-COL9A1]-D6S30. In addition, using an interspecific backcross panel, they have mapped murine Col9a1 to mouse chromosome 1. Together with other comparative mapping results, these data suggest that the pericentric region of human chromosome 6 is homologous to the most proximal segment of mouse chromosome 1. These data may facilitate linkage studies with COL9A1 (or col9a1) as a candidate gene for hereditary chondrodysplasias and osteoarthritis. 35 refs., 2 figs., 2 tabs.

  17. Analysis of Xq27-28 linkage in the international consortium for prostate cancer genetics (ICPCG families

    Directory of Open Access Journals (Sweden)

    Bailey-Wilson Joan E

    2012-06-01

    Full Text Available Abstract Background Genetic variants are likely to contribute to a portion of prostate cancer risk. Full elucidation of the genetic etiology of prostate cancer is difficult because of incomplete penetrance and genetic and phenotypic heterogeneity. Current evidence suggests that genetic linkage to prostate cancer has been found on several chromosomes including the X; however, identification of causative genes has been elusive. Methods Parametric and non-parametric linkage analyses were performed using 26 microsatellite markers in each of 11 groups of multiple-case prostate cancer families from the International Consortium for Prostate Cancer Genetics (ICPCG. Meta-analyses of the resultant family-specific linkage statistics across the entire 1,323 families and in several predefined subsets were then performed. Results Meta-analyses of linkage statistics resulted in a maximum parametric heterogeneity lod score (HLOD of 1.28, and an allele-sharing lod score (LOD of 2.0 in favor of linkage to Xq27-q28 at 138 cM. In subset analyses, families with average age at onset less than 65 years exhibited a maximum HLOD of 1.8 (at 138 cM versus a maximum regional HLOD of only 0.32 in families with average age at onset of 65 years or older. Surprisingly, the subset of families with only 2–3 affected men and some evidence of male-to-male transmission of prostate cancer gave the strongest evidence of linkage to the region (HLOD = 3.24, 134 cM. For this subset, the HLOD was slightly increased (HLOD = 3.47 at 134 cM when families used in the original published report of linkage to Xq27-28 were excluded. Conclusions Although there was not strong support for linkage to the Xq27-28 region in the complete set of families, the subset of families with earlier age at onset exhibited more evidence of linkage than families with later onset of disease. A subset of families with 2–3 affected individuals and with some evidence of male to male disease transmission

  18. Fine mapping of susceptibility genes by Lewontin's linkage disequilibrium measure with application to Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objectives To formulate an equation for fine mapping of disease loci under complex conditions and determine the marker-disease distance in a specific case using this equation. Methods Lewontin's linkage disequilibrium (LD) measure D' was used to formulate an equation for mapping disease genes in the presence of phenocopies, locus heterogeneity, gene-gene and gene-environment interactions, incomplete penetrance, uncertain liability and threshold, incomplete initial LD, natural selection, recurrent mutation, high disease allele frequency and unknown mode of inheritance. This equation was then used to determine the distance between a marker (ε4 within the apolipoprotein E gene, APOE) and Alzheimer's disease (AD) loci using published data.Results An equation was formulated for mapping disease genes under the above conditions. If these conditions are present but ignored, then recombination fraction θ between marker and disease loci will be either overestimated or estimated with little bias. Therefore, an upper limit of θ can be obtained. AD has been found to be associated with the marker allele ε4 in Africans, Asians, and Caucasians. This suggests that the AD-ε4 allelic LD predates the divergence of peoples occurring 100·!000 years ago. With the age of AD-ε4 allelic LD so estimated, the maximal distance was calculated to be 23.2 kb (mean 5.8 kb).Conclusions (1) A method is developed for LD mapping of susceptibility genes. (2) A mutation within the APOE gene itself, among others, is responsible for the susceptibility to AD, which is supported by recent evidence from studies using transgenic mice.

  19. Genetic linkage maps of chicken chromosomes 6, 7, 8, 11 and 13 from a Brazilian resource population Mapas de ligação dos cromossomos 6, 7, 8, 11 e 13 de uma população brasileira de galinha

    Directory of Open Access Journals (Sweden)

    Marcel Ambo

    2008-01-01

    Full Text Available A linkage map is essential not only for quantitative trait loci (QTL mapping, but also for the organization and location of genes along the chromosomes. The present study is part of a project whose major objective is, besides from construction the linkage maps, the whole genome scan for mapping QTL for performance traits in the Brazilian experimental chicken population. Linkage maps of chicken chromosomes 6 to 8, 11 and 13 were constructed based on this population. The population was developed from two generations of crossbreeding between a broiler and a layer line. Fifty-one microsatellite markers were tested, from which 28 were informative: 4, 8, 7, 4 and 5 for chromosomes 6, 7, 8, 11 and 13, respectively. A SNP located in the leptin receptor gene was included for chromosome 8. Ten parental, 8 F1 and 459 F2 chickens from five full-sib families were genotyped with these markers. The number of total informative meioses per locus varied from 232 to 862, and the number of phase-known informative meioses from 0 to 764. Marker orders in the chromosomes coincided with those of the chicken consensus map, except for markers ADL0147 and MCW0213, on chromosome 13, which were inverted. The reduced number of phase-known informative meioses for ADL0147 (150 may be pointed out as a possible cause for this inversion, apart from the relative short distance between the two markers involved in the inversion (10.5 cM.O mapa de ligação além de ser fundamental no mapeamento de locos de características quantitativas (QTLs é importante na organização e localização de genes distribuídos ao longo dos cromossomos. O presente estudo é parte de um trabalho cujo objetivo maior, é a análise de mapeamento de QTLs para características de desempenho no genoma de uma população experimental desenvolvida no Brasil. Com base nesta população foram construídos os mapas de ligação dos cromossomos 6 a 8, 11 e 13 da galinha. A população foi desenvolvida a partir

  20. BATTEN-DISEASE GENE, CLN3 - LINKAGE DISEQUILIBRIUM MAPPING IN THE FINNISH POPULATION, AND ANALYSIS OF EUROPEAN HAPLOTYPES

    NARCIS (Netherlands)

    MITCHISON, HM; ORAWE, AM; TASCHNER, PEM; SANDKUIJL, LA; SANTAVUORI, P; DEVOS, N; BREUNING, MH; MOLE, SE; GARDINER, RM; JARVELA, IE

    The gene for Batten disease (juvenile-onset neuronal ceroid lipofuscinosis, or Spielmeyer-Sjogren disease), CLN3, maps to 16p11.2-12.1. Four microsatellite markers-D16S288, D16S299, D16S298, and SPN-are in strong linkage disequilibrium with CLN3 in 142 families from 16 different countries. These

  1. Construction of intersubspecific molecular genetic map of lentil based on ISSR, RAPD and SSR markers

    Indian Academy of Sciences (India)

    Mamta Gupta; Bhawna Verma; Naresh Kumar; Rakesh K. Chahota; Rajeev Rathour; Shyam K. Sharma; Sabhyata Bhatia; Tilak R. Sharma

    2012-12-01

    Lentil (Lens culinaris ssp. culinaris), is a self-pollinating diploid ($2n = 2x = 14$), cool-season legume crop and is consumed worldwide as a rich source of protein (∼24.0%), largely in vegetarian diets. Here we report development of a genetic linkage map of Lens using 114 F2 plants derived from the intersubspecific cross between L 830 and ILWL 77. RAPD (random amplified polymorphic DNA) primers revealed more polymorphism than ISSR (intersimple sequence repeat) and SSR (simple sequence repeat) markers. The highest proportion (30.72%) of segregation distortion was observed in RAPD markers. Of the 235 markers (34 SSR, 9 ISSR and 192 RAPD) used in the mapping study, 199 (28 SSRs, 9 ISSRs and 162 RAPDs) were mapped into 11 linkage groups (LGs), varying between 17.3 and 433.8 cM and covering 3843.4 cM, with an average marker spacing of 19.3 cM. Linkage analysis revealed nine major groups with 15 or more markers each and two small LGs with two markers each, and 36 unlinked markers. The study reported assigning of 11 new SSRs on the linkage map. Of the 66 markers with aberrant segregation, 14 were unlinked and the remaining 52 were mapped. ISSR and RAPD markers were found to be useful in map construction and saturation. The current map represents maximum coverage of lentil genome and could be used for identification of QTL regions linked to agronomic traits, and for marker-assisted selection in lentil.

  2. Genetic linkage studies in familial partial epilepsy: Exclusion of the human chromosome regions syntenic to the El-1 mouse locus

    Energy Technology Data Exchange (ETDEWEB)

    Lopes-Cendes, I. [Montreal General Hospital (Canada); Mulley, J.C. [Alelaide Children`s Hospital (Canada); Andermann, E. [Montreal Neurological Institute and Hospital, Quebec (Canada)] [and others

    1994-09-01

    Recently, six families with a familial form of partial epilepsy were described. All pedigrees showed autosomal dominant inheritance with incomplete penetrance. Affected individuals present with predominantly nocturnal seizures with frontal lobe semiology. In 1959, a genetic mouse model for partial epilepsy, the El mouse, was reported. In the El mouse, a major seizure susceptibility gene, El-1, segregates in an autosomal dominant fashion and has been localized to a region distal to the centromere of mouse chromosome 9. Comparative genetic maps between man and mouse have been used for prediction of localization of several human disease genes. Because the region of mouse chromosome 9 that is the most likely to contain the El-1 locus is syntenic to regions on human chromosomes 3q21-p22, 3q21-q23.3, 6q12 and 15q24, we adopted the candidate gene approach as an initial linkage strategy. Twenty-two polymorphic microsatellite markers covering these regions were used for genotyping individuals in the three larger families ascertained, two of which are Australian and one French-Canadian. Negative two-point lod scores were obtained separately for each family. The analysis of all three families combined significantly excludes the candidate regions on chromosomes 3, 6 and 15.

  3. An SSR-based linkage map of yardlong bean (Vigna unguiculata (L.) Walp. subsp. unguiculata Sesquipedalis Group) and QTL analysis of pod length.

    Science.gov (United States)

    Kongjaimun, Alisa; Kaga, Akito; Tomooka, Norihiko; Somta, Prakit; Shimizu, Takehiko; Shu, Yujian; Isemura, Takehisa; Vaughan, Duncan A; Srinives, Peerasak

    2012-02-01

    Yardlong bean (Vigna unguiculata (L.) Walp. subsp. unguiculata Sesquipedalis Group) (2n = 2x = 22) is one of the most important vegetable legumes of Asia. The objectives of this study were to develop a genetic linkage map of yardlong bean using SSR makers from related Vigna species and to identify QTLs for pod length. The map was constructed from 226 simple sequence repeat (SSR) markers from cowpea (Vigna unguiculata (L.) Walp. subsp. unguiculata Unguiculata Group), azuki bean (Vigna angularis (Willd.) Ohwi & Ohashi), and mungbean (Vigna radiata (L.) Wilczek) in a BC(1)F(1) ((JP81610 × TVnu457) × JP81610) population derived from the cross between yardlong bean accession JP81610 and wild cowpea (Vigna unguiculata subsp. unguiculata var. spontanea) accession TVnu457. The markers were clustered into 11 linkage groups (LGs) spanning 852.4 cM in total length with a mean distance between adjacent markers of 3.96 cM. All markers on LG11 showed segregation distortion towards the homozygous yardlong bean JP81610 genotype. The markers on LG11 were also distorted in the rice bean (Vigna umbellata (Thunb.) Ohwi & Ohashi) map, suggesting the presence of common segregation distortion factors in Vigna species on this LG. One major and six minor QTLs were identified for pod length variation between yardlong bean and wild cowpea. Using flanking markers, six of the seven QTLs were confirmed in an F(2) population of JP81610 × TVnu457. The molecular linkage map developed and markers linked to pod length QTLs would be potentially useful for yardlong bean and cowpea breeding.

  4. Rate of decay in admixture linkage disequilibrium and its implication in gene mapping

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Modeling linkage disequilibria (LD) between genes usually observed in admixed natural populations has been shown an effective approach in high-resolution mapping of disease genes in humans. A prerequisite to obtain accurate estimation of recombination fraction between genes at a marker locus and the disease locus using the approach is a reliable prediction of the proportion of the admixture populations. The present study suggested the use of gene frequencies to predict the estimate of the admixture propor-tion based on the observation that the gene frequencies are much more stable quantities than the haplotype frequencies over evolution of the population. In this paper, we advanced the theory and methods by which the decay rate of nonlinear term of LD in admixed population may be used to estimate the recombination fraction between the genes. Theoretical analysis and simulation study indicate that, the larger the difference of gene frequencies between parental populations and the more closely the admixture proportion approaches 0.5, the more important the nonlinear term of the LD in the admixed population, and hence the more informative such admixed populations in the high-resolution gene mapping practice.

  5. Genetic linkage of bipolar disorder to chromosome 6q22 is a consistent finding in Portuguese subpopulations and may generalize to broader populations.

    Science.gov (United States)

    Pato, Carlos N; Middleton, Frank A; Gentile, Karen L; Morley, Christopher P; Medeiros, Helena; Macedo, Antonio; Azevedo, M Helena; Pato, Michele T

    2005-04-05

    We recently reported genome-wide significant linkage to chromosome 6q for bipolar disorder, in a study of 25 Portuguese families, using the Human Mapping Assay Xba 131 (HMA10K). To explore the generalizability of this finding, we reanalyzed our SNP linkage data according to the families' geographic origin. Specifically, the 25 families included 20 families from the Portuguese island collection (PIC; 15 families from the Azores Islands and 5 from the Madeira Islands) and 5 families from continental Portugal. Non-parametric linkage analysis (NPL) was performed as previously described and indicated that each of these subpopulations showed evidence of linkage for the same region. To further address the potential generalizability of these findings to other populations, we have also examined allelic heterozygosity in our subpopulations and in three reference populations (Caucasian, East Asian, and African-American). This analysis indicated that the PIC population is highly correlated to the Caucasian reference population (R = 0.86) for all of chromosome 6. In contrast allelic heterozygosity was more weakly correlated between PIC and both East Asian (R = 0.37) and African-American (R = 0.32) reference populations. Taken together these observations suggest a shared genetic liability among Portuguese populations for bipolar disorder on chromosome 6q, and that the PIC population is likely representative of Caucasians in general. Copyright 2005 Wiley-Liss, Inc.

  6. Construction of high-quality recombination maps with low-coverage genomic sequencing for joint linkage analysis in maize

    Science.gov (United States)

    A genome-wide association study (GWAS) is the foremost strategy used for finding genes that control human diseases and agriculturally important traits, but it often reports false positives. In contrast, its complementary method, linkage analysis, provides direct genetic confirmation, but with limite...

  7. Genetic mapping and identification of QTL for earliness in the globe artichoke/cultivated cardoon complex

    Directory of Open Access Journals (Sweden)

    Portis Ezio

    2012-05-01

    Full Text Available Abstract Background The Asteraceae species Cynara cardunculus (2n = 2x = 34 includes the two fully cross-compatible domesticated taxa globe artichoke (var. scolymus L. and cultivated cardoon (var. altilis DC. As both are out-pollinators and suffer from marked inbreeding depression, linkage analysis has focussed on the use of a two way pseudo-test cross approach. Results A set of 172 microsatellite (SSR loci derived from expressed sequence tag DNA sequence were integrated into the reference C. cardunculus genetic maps, based on segregation among the F1 progeny of a cross between a globe artichoke and a cultivated cardoon. The resulting maps each detected 17 major linkage groups, corresponding to the species’ haploid chromosome number. A consensus map based on 66 co-dominant shared loci (64 SSRs and two SNPs assembled 694 loci, with a mean inter-marker spacing of 2.5 cM. When the maps were used to elucidate the pattern of inheritance of head production earliness, a key commercial trait, seven regions were shown to harbour relevant quantitative trait loci (QTL. Together, these QTL accounted for up to 74% of the overall phenotypic variance. Conclusion The newly developed consensus as well as the parental genetic maps can accelerate the process of tagging and eventually isolating the genes underlying earliness in both the domesticated C. cardunculus forms. The largest single effect mapped to the same linkage group in each parental maps, and explained about one half of the phenotypic variance, thus representing a good candidate for marker assisted selection.

  8. Linkage effects and analysis of finite sample errors in the HapMap.

    Science.gov (United States)

    Zaitlen, Noah; Kang, Hyun Min; Eskin, Eleazar

    2009-01-01

    The HapMap provides a valuable resource to help uncover genetic variants of important complex phenotypes such as disease risk and outcome. Using the HapMap we can infer the patterns of LD within different human populations. This is a critical step for determining which SNPs to genotype as part of a study, estimating study power, designing a follow-up study to identify the causal variants, 'imputing' untyped SNPs, and estimating recombination rates along the genome. Despite its tremendous importance, the HapMap suffers from the fundamental limitation that at most 60 unrelated individuals are available per population. We present an analytical framework for analyzing the implications of a finite sample HapMap. We present and justify simple approximations for deriving analytical estimates of important statistics such as the square of the correlation coefficient r(2) between two SNPs. Finally, we use this framework to show that current HapMap based estimates of r(2) and power have significant errors, and that tag sets highly overestimate their coverage. We show that a reasonable increase in the number of individuals, such as that proposed by the 1000 genomes project, greatly reduces the errors due to finite sample size for a large proportion of SNPs.

  9. Immune Genetic Learning of Fuzzy Cognitive Map

    Institute of Scientific and Technical Information of China (English)

    LIN Chun-mei; HE Yue; TANG Bing-yong

    2006-01-01

    This paper presents a hybrid methodology of automatically constructing fuzzy cognitive map (FCM). The method uses immune genetic algorithm to learn the connection matrix of FCM. In the algorithm, the DNA coding method is used and an immune operator based on immune mechanism is constructed. The characteristics of the system and the experts' knowledge are abstracted as vaccine for restraining the degenerative phenomena during evolution so as to improve the algorithmic efficiency. Finally, an illustrative example is provided, and its results suggest that the method is capable of automatically generating FCM model.

  10. Linkage study of nonsyndromic cleft lip with or without cleft palate using candidate genes and mapped polymorphic markers

    Energy Technology Data Exchange (ETDEWEB)

    Stein, J.D.; Nelson, L.D.; Conner, B.J. [Univ. of Texas, Houston (United States)] [and others

    1994-09-01

    Nonsyndromic cleft lip with or without cleft palate (CL(P)) involves fusion or growth failure of facial primordia during development. Complex segregation analysis of clefting populations suggest that an autosomal dominant gene may play a role in this common craniofacial disorder. We have ascertained 16 multigenerational families with CL(P) and tested linkage to 29 candidate genes and 139 mapped short tandem repeat markers. The candidate genes were selected based on their expression in craniofacial development or were identified through murine models. These include: TGF{alpha}, TGF{beta}1, TGF{beta}2, TGF{beta}3, EGF, EGFR, GRAS, cMyc, FGFR, Jun, JunB, PDFG{alpha}, PDGF{beta}, IGF2R, GCR Hox7, Hox8, Hox2B, twirler, 5 collagen and 3 extracellular matrix genes. Linkage was tested assuming an autosomal dominant model with sex-specific decreased penetrance. Linkage to all of the candidate loci was excluded in 11 families. RARA was tested and was not informative. However, haplotype analysis of markers flanking RARA on 17q allowed exclusion of this candidate locus. We have previously excluded linkage to 61 STR markers in 11 families. Seventy-eight mapped short tandem repeat markers have recently been tested in 16 families and 30 have been excluded. The remaining are being analyzed and an exclusion map is being developed based on the entire study results.

  11. Genome-wide linkage scan identifies two novel genetic loci for coronary artery disease: in GeneQuest families.

    Science.gov (United States)

    Gao, Hanxiang; Li, Lin; Rao, Shaoqi; Shen, Gongqing; Xi, Quansheng; Chen, Shenghan; Zhang, Zheng; Wang, Kai; Ellis, Stephen G; Chen, Qiuyun; Topol, Eric J; Wang, Qing K

    2014-01-01

    Coronary artery disease (CAD) is the leading cause of death worldwide. Recent genome-wide association studies (GWAS) identified >50 common variants associated with CAD or its complication myocardial infarction (MI), but collectively they account for missing heritability". Rare variants with large effects may account for a large portion of missing heritability. Genome-wide linkage studies of large families and follow-up fine mapping and deep sequencing are particularly effective in identifying rare variants with large effects. Here we show results from a genome-wide linkage scan for CAD in multiplex GeneQuest families with early onset CAD and MI. Whole genome genotyping was carried out with 408 markers that span the human genome by every 10 cM and linkage analyses were performed using the affected relative pair analysis implemented in GENEHUNTER. Affected only nonparametric linkage (NPL) analysis identified two novel CAD loci with highly significant evidence of linkage on chromosome 3p25.1 (peak NPL  = 5.49) and 3q29 (NPL  = 6.84). We also identified four loci with suggestive linkage on 9q22.33, 9q34.11, 17p12, and 21q22.3 (NPL  = 3.18-4.07). These results identify novel loci for CAD and provide a framework for fine mapping and deep sequencing to identify new susceptibility genes and novel variants associated with risk of CAD.

  12. Genetic analysis and QTL mapping of seed coat color in sesame (Sesamum indicum L.).

    Science.gov (United States)

    Zhang, Haiyang; Miao, Hongmei; Wei, Libin; Li, Chun; Zhao, Ruihong; Wang, Cuiying

    2013-01-01

    Seed coat color is an important agronomic trait in sesame, as it is associated with seed biochemical properties, antioxidant content and activity and even disease resistance of sesame. Here, using a high-density linkage map, we analyzed genetic segregation and quantitative trait loci (QTL) for sesame seed coat color in six generations (P1, P2, F1, BC1, BC2 and F2). Results showed that two major genes with additive-dominant-epistatic effects and polygenes with additive-dominant-epistatic effects were responsible for controlling the seed coat color trait. Average heritability of the major genes in the BC1, BC2 and F2 populations was 89.30%, 24.00%, and 91.11% respectively, while the heritability of polygenes was low in the BC1 (5.43%), in BC2 (0.00%) and in F2 (0.89%) populations. A high-density map was constructed using 724 polymorphic markers. 653 SSR, AFLP and RSAMPL loci were anchored in 14 linkage groups (LG) spanning a total of 1,216.00 cM. The average length of each LG was 86.86 cM and the marker density was 1.86 cM per marker interval. Four QTLs for seed coat color, QTL1-1, QTL11-1, QTL11-2 and QTL13-1, whose heritability ranged from 59.33%-69.89%, were detected in F3 populations using CIM and MCIM methods. Alleles at all QTLs from the black-seeded parent tended to increase the seed coat color. Results from QTLs mapping and classical genetic analysis among the P1, P2, F1, BC1, BC2 and F2 populations were comparatively consistent. This first QTL analysis and high-density genetic linkage map for sesame provided a good foundation for further research on sesame genetics and molecular marker-assisted selection (MAS).

  13. A consensus microsatellite-based linkage map for the hermaphroditic bay scallop (Argopecten irradians and its application in size-related QTL analysis.

    Directory of Open Access Journals (Sweden)

    Hongjun Li

    Full Text Available Bay scallop (Argopecten irradians is one of the most economically important aquaculture species in China. In this study, we constructed a consensus microsatellite-based genetic linkage map with a mapping panel containing two hybrid backcross-like families involving two subspecies of bay scallop, A. i. irradians and A. i. concentricus. One hundred sixty-one microsatellite and one phenotypic (shell color markers were mapped to 16 linkage groups (LGs, which corresponds to the haploid chromosome number of bay scallop. The sex-specific map was 779.2 cM and 781.6 cM long in female and male, respectively, whereas the sex-averaged map spanned 849.3 cM. The average resolution of integrated map was 5.9 cM/locus and the estimated coverage was 81.3%. The proportion of distorted markers occurred more in the hybrid parents, suggesting that the segregation distortion was possibly resulted from heterospecific interaction between genomes of two subspecies of bay scallop. The overall female-to-male recombination rate was 1.13:1 across all linked markers in common to both parents, and considerable differences in recombination also existed among different parents in both families. Four size-related traits, including shell length (SL, shell height (SH, shell width (SW and total weight (TW were measured for quantitative trait loci (QTL analysis. Three significant and six suggestive QTL were detected on five LGs. Among the three significant QTL, two (qSW-10 and qTW-10, controlling SW and TW, respectively were mapped on the same region near marker AiAD121 on LG10 and explained 20.5% and 27.7% of the phenotypic variance, while the third (qSH-7, controlling SH was located on LG7 and accounted for 15.8% of the phenotypic variance. Six suggestive QTL were detected on four different LGs. The linkage map and size-related QTL obtained in this study may facilitate marker-assisted selection (MAS in bay scallop.

  14. Mapping genetic factors controlling potato/cyst nematode interactions.

    NARCIS (Netherlands)

    Rouppe van der Voort, J.N.A.M.

    1998-01-01

    The thesis describes strategies for genetic mapping of the genomes of the potato cyst nematode and potato. Mapping in cyst nematodes was achieved by AFLP genotyping of single cysts and subsequent segregation analysis in a family of sibling populations. The genetic map of Globodera rostochiensis comp

  15. Development of a 10,000 locus genetic map of the sunflower genome based on multiple crosses.

    Science.gov (United States)

    Bowers, John E; Bachlava, Eleni; Brunick, Robert L; Rieseberg, Loren H; Knapp, Steven J; Burke, John M

    2012-07-01

    Genetic linkage maps have the potential to facilitate the genetic dissection of complex traits and comparative analyses of genome structure, as well as molecular breeding efforts in species of agronomic importance. Until recently, the majority of such maps was based on relatively low-throughput marker technologies, which limited marker density across the genome. The availability of high-throughput genotyping technologies has, however, made possible the efficient development of high-density genetic maps. Here, we describe the analysis and integration of genotypic data from four sunflower (Helianthus annuus L.) mapping populations to produce a consensus linkage map of the sunflower genome. Although the individual maps (which contained 3500-5500 loci each) were highly colinear, we observed localized variation in recombination rates in several genomic regions. We also observed several gaps up to 26 cM in length that completely lacked mappable markers in individual crosses, presumably due to regions of identity by descent in the mapping parents. Because these regions differed by cross, the consensus map of 10,080 loci contained no such gaps, clearly illustrating the value of simultaneously analyzing multiple mapping populations.

  16. Effect of Co-segregating Markers on High-Density Genetic Maps and Prediction of Map Expansion Using Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Amidou N’Diaye

    2017-08-01

    Full Text Available Advances in sequencing and genotyping methods have enable cost-effective production of high throughput single nucleotide polymorphism (SNP markers, making them the choice for linkage mapping. As a result, many laboratories have developed high-throughput SNP assays and built high-density genetic maps. However, the number of markers may, by orders of magnitude, exceed the resolution of recombination for a given population size so that only a minority of markers can accurately be ordered. Another issue attached to the so-called ‘large p, small n’ problem is that high-density genetic maps inevitably result in many markers clustering at the same position (co-segregating markers. While there are a number of related papers, none have addressed the impact of co-segregating markers on genetic maps. In the present study, we investigated the effects of co-segregating markers on high-density genetic map length and marker order using empirical data from two populations of wheat, Mohawk × Cocorit (durum wheat and Norstar × Cappelle Desprez (bread wheat. The maps of both populations consisted of 85% co-segregating markers. Our study clearly showed that excess of co-segregating markers can lead to map expansion, but has little effect on markers order. To estimate the inflation factor (IF, we generated a total of 24,473 linkage maps (8,203 maps for Mohawk × Cocorit and 16,270 maps for Norstar × Cappelle Desprez. Using seven machine learning algorithms, we were able to predict with an accuracy of 0.7 the map expansion due to the proportion of co-segregating markers. For example in Mohawk × Cocorit, with 10 and 80% co-segregating markers the length of the map inflated by 4.5 and 16.6%, respectively. Similarly, the map of Norstar × Cappelle Desprez expanded by 3.8 and 11.7% with 10 and 80% co-segregating markers. With the increasing number of markers on SNP-chips, the proportion of co-segregating markers in high-density maps will continue to increase

  17. Oat Anther Culture and Use of DH-Lines for Genetic Mapping.

    Science.gov (United States)

    Kiviharju, Elina; Moisander, Sirpa; Tanhuanpää, Pirjo

    2017-01-01

    Possibility to make doubled haploids (DHs) from varying crossing populations is a useful tool for enhancing cultivar breeding, and a source of valuable material for genetic research. Oats is reported to be recalcitrant in anther culture with low response and genotype dependency. However, the best recoveries reported have reached up to 30 green regenerants per 100 isolated anthers, which clearly addresses the potential of this technique. In this chapter, one successful oat anther culture protocol is described in detail. Due to the total homozygosity reached in one generation, DH-lines are also an excellent material for genetic mapping. In this chapter, the use of DH-mapping population for marker analyses and linkage mapping is presented.

  18. Comparative mapping in the Fagaceae and beyond with EST-SSRs

    NARCIS (Netherlands)

    Bodenes, C.; Chancerel, E.; Gailing, O.; Vendramin, G.G.; Bagnoli, F.; Durand, J.; Goicoechea, P.G.; Soliani, C.; Villani, F.; Mattioni, C.; Koelewijn, H.P.; Murat, F.; Salse, J.; Roussel, G.; Boury, C.; Alberto, F.; Kremer, A.; Plomion, C.

    2012-01-01

    Background: Genetic markers and linkage mapping are basic prerequisites for comparative genetic analyses, QTL detection and map-based cloning. A large number of mapping populations have been developed for oak, but few gene-based markers are available for constructing integrated genetic linkage maps

  19. Conserved synteny between pig chromosome 8 and human chromosome 4 but rearranged and distorted linkage maps

    Energy Technology Data Exchange (ETDEWEB)

    Ellegren, H.; Edfors-Lilja, I.; Anderson, L. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)); Wintero, A.K. (Royal Veterinary and Agricultural Univ., Fredriksberg (Denmark))

    1993-09-01

    The porcine genes encoding interleukin 2, alcohol dehydrogenase (class I) gamma polypeptide, and osteopontin were mapped to chromosome 8 by linkage analysis. Together with previous assignments to this chromosome (the albumin, platelet-derived growth factor receptor A, and fibrinogen genes), an extensive syntenic homology with human chromosome 4 was discovered. Loci from about three-quarters of the q arm of human chromosome 4 are on pig chromosome 8. However, the linear order of the markers is not identical in the two species, and there are several examples of interspecific differences in the recombination fractions between adjacent markers. The conserved synteny between man and the pig gives strong support to a previous suggestion that a synteny group present in the ancestor of mammalian species has been retained on human chromosome 4q. Since loci from this synteny group are found on two cattle chromosomes, the bovine rearrangement must have occurred after the split of Suidae and Bovidae within Artiodactyla. 29 refs., 3 figs., 1 tab.

  20. Genetic linkage of distinct adaptive traits in sympatrically speciating crater lake cichlid fish

    Science.gov (United States)

    Fruciano, Carmelo; Franchini, Paolo; Kovacova, Viera; Elmer, Kathryn R.; Henning, Frederico; Meyer, Axel

    2016-01-01

    Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow. Here we investigate the genomic basis of adaptive traits, focusing on a sympatrically diverging species pair of crater lake cichlid fishes. We identify the main quantitative trait loci (QTL) for two eco-morphological traits: body shape and pharyngeal jaw morphology. These traits diverge in parallel between benthic and limnetic species in the repeated adaptive radiations of this and other fish lineages. Remarkably, a single chromosomal region contains the highest effect size QTL for both traits. Transcriptomic data show that the QTL regions contain genes putatively under selection. Independent population genomic data corroborate QTL regions as areas of high differentiation between the sympatric sister species. Our results provide empirical support for current theoretical models that emphasize the importance of genetic linkage and pleiotropy in facilitating rapid divergence in sympatry. PMID:27597183

  1. Genetic linkage of mild pseudoachondroplasia (PSACH) to markers in the pericentromeric region of chromosome 19

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, M.D.; Rasmussen, M.; Garber, P.; Rimoin, D.L.; Cohn, D.H. (Steven Spielberg Pediatric Research Center, Los Angeles, CA (United States)); Weber, J.L. (Marshfield Medical Research Foundation, WI (United States)); Yuen, J.; Reinker, K. (Univ. of Hawaii, Honolulu, HI (United States))

    1993-12-01

    Pseudoachondroplasia (PSACH) is a dominantly inherited form of short-limb dwarfism characterized by dysplastic changes in the spine, epiphyses, and metaphyses and early onset osteoarthropathy. Chondrocytes from affected individuals accumulate an unusual appearing material in the rough endoplasmic reticulum, which has led to the hypothesis that a structural abnormality in a cartilage-specific protein produces the phenotype. The authors recently identified a large family with a mild form of pseudoachondroplasia. By genetic linkage to a dinucleotide repeat polymorphic marker (D19S199), they have localized the disease gene to chromosome 19 (maximum lod score of 7.09 at a recombination fraction of 0.03). Analysis of additional markers and recombinations between the linked markers and the phenotype suggests that the disease gene resides within a 6.3-cM interval in the immediate pericentromeric region of the chromosome. 39 refs., 2 figs., 1 tab.

  2. Setting up Multiplex Panels for Genetic Testing of Familial Hy¬pertrophic Cardiomyopathy Based on Linkage Analysis

    Directory of Open Access Journals (Sweden)

    Hoorieh SAGHAFI

    2016-03-01

    Full Text Available Background: Familial hypertrophic cardiomyopathy (HCM is caused by mutations in genes encoding cardiac sarcomere proteins. Nowadays genetic testing of HCM plays an important role in clinical practice by contributing to the diagnosis, prognosis, and screening of high-risk individuals. The aim of this study was developing a reliable testing strategy for HCM based on linkage analysis and appropriate for Iranian population.Methods: Six panels of four microsatellite markers surrounding MYH7, MYBPC3, TNNT2, TNNI3, TPM1, and MYL2 genes (24 markers in total were selected for multiplex PCR and fragment length analysis. Characteristics of markers and informativeness of the panels were evaluated in 50 unrelated Iranians. The efficacy of the strategy was verified in a family with HCM.Results: All markers were highly polymorphic. The panels were informative in 96-100% of samples. Multipoint linkage analysis excluded the linkage between the disease and all six genes by obtaining maximum LOD score ≤-2.Conclusion: This study suggests a reliable genetic testing method based on linkage analysis between 6 sarcomere genes and familial HCM. It could be applied for diagnostic, predictive, or screening testing in clinical setting. Keywords: Cardiomyopathy, Hypertrophic, Genetic linkage, Diagnosis 

  3. Genetic mapping of resistance to Fusarium oxysporum f. sp. tulipae in tulip.

    Science.gov (United States)

    Tang, Nan; van der Lee, Theo; Shahin, Arwa; Holdinga, Maarten; Bijman, Paul; Caser, Matteo; Visser, Richard G F; van Tuyl, Jaap M; Arens, Paul

    Fusarium oxysporum is a major problem in the production of tulip bulbs. Breeding for resistant cultivars through a conventional approach is a slow process due to the long life cycle of tulip. Until now, marker-assisted selection (MAS) has been hampered by the large genome size and the absence of a genetic map. This study is aimed at construction of the first genetic map for tulip and at the identification of loci associated with resistance to F. oxysporum. A cross-pollinated population of 125 individuals segregating for Fusarium resistance was obtained from Tulipa gesneriana "Kees Nelis" and T. fosteriana "Cantata." Fusarium resistance of the mapping population was evaluated through a soil infection test in two consecutive years, and a spot inoculation test in which a green fluorescent protein tagged Fusarium strain was used for inoculation. The genetic maps have been constructed for the parents separately. The genetic map of "Kees Nelis" comprised 342 markers on 27 linkage groups covering 1707 cM, while the map of "Cantata" comprised 300 markers on 21 linkage groups covering 1201 cM. Median distance between markers was 3.9 cM for "Kees Nelis" and 3.1 cM for "Cantata." Six putative quantitative trait loci (QTLs) for Fusarium resistance were identified, derived from both parents. QTL2, QTL3, and QTL6 were significant in all disease tests. For the flanking markers of the QTLs, phenotypic means of the two allelic groups, segregating from a parent for such a marker, were significantly different. These markers will be useful for the development of MAS in tulip breeding.

  4. Genetic mapping and QTL analysis of growth-related traits in Pinctada fucata using restriction-site associated DNA sequencing.

    Directory of Open Access Journals (Sweden)

    Yaoguo Li

    Full Text Available The pearl oyster, Pinctada fucata (P. fucata, is one of the marine bivalves that is predominantly cultured for pearl production. To obtain more genetic information for breeding purposes, we constructed a high-density linkage map of P. fucata and identified quantitative trait loci (QTL for growth-related traits. One F1 family, which included the two parents, 48 largest progeny and 50 smallest progeny, was sampled to construct a linkage map using restriction site-associated DNA sequencing (RAD-Seq. With low coverage data, 1956.53 million clean reads and 86,342 candidate RAD loci were generated. A total of 1373 segregating SNPs were used to construct a sex-average linkage map. This spanned 1091.81 centimorgans (cM, with 14 linkage groups and an average marker interval of 1.41 cM. The genetic linkage map coverage, Coa, was 97.24%. Thirty-nine QTL-peak loci, for seven growth-related traits, were identified using the single-marker analysis, nonparametric mapping Kruskal-Wallis (KW test. Parameters included three for shell height, six for shell length, five for shell width, four for hinge length, 11 for total weight, eight for soft tissue weight and two for shell weight. The QTL peak loci for shell height, shell length and shell weight were all located in linkage group 6. The genotype frequencies of most QTL peak loci showed significant differences between the large subpopulation and the small subpopulation (P<0.05. These results highlight the effectiveness of RAD-Seq as a tool for generation of QTL-targeted and genome-wide marker data in the non-model animal, P. fucata, and its possible utility in marker-assisted selection (MAS.

  5. Confirmation and Fine Mapping of a Major QTL for Aflatoxin Resistance in Maize Using a Combination of Linkage and Association Mapping

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2016-09-01

    Full Text Available Maize grain contamination with aflatoxin from Aspergillus flavus (A. flavus is a serious health hazard to animals and humans. To map the quantitative trait loci (QTLs associated with resistance to A. flavus, we employed a powerful approach that differs from previous methods in one important way: it combines the advantages of the genome-wide association analysis (GWAS and traditional linkage mapping analysis. Linkage mapping was performed using 228 recombinant inbred lines (RILs, and a highly significant QTL that affected aflatoxin accumulation, qAA8, was mapped. This QTL spanned approximately 7 centi-Morgan (cM on chromosome 8. The confidence interval was too large for positional cloning of the causal gene. To refine this QTL, GWAS was performed with 558,629 single nucleotide polymorphisms (SNPs in an association population comprising 437 maize inbred lines. Twenty-five significantly associated SNPs were identified, most of which co-localised with qAA8 and explained 6.7% to 26.8% of the phenotypic variation observed. Based on the rapid linkage disequilibrium (LD and the high density of SNPs in the association population, qAA8 was further localised to a smaller genomic region of approximately 1500 bp. A high-resolution map of the qAA8 region will be useful towards a marker-assisted selection (MAS of A. flavus resistance and a characterisation of the causal gene.

  6. Confirmation and Fine Mapping of a Major QTL for Aflatoxin Resistance in Maize Using a Combination of Linkage and Association Mapping

    Science.gov (United States)

    Zhang, Yu; Cui, Min; Zhang, Jimin; Zhang, Lei; Li, Chenliu; Kan, Xin; Sun, Qian; Deng, Dexiang; Yin, Zhitong

    2016-01-01

    Maize grain contamination with aflatoxin from Aspergillus flavus (A. flavus) is a serious health hazard to animals and humans. To map the quantitative trait loci (QTLs) associated with resistance to A. flavus, we employed a powerful approach that differs from previous methods in one important way: it combines the advantages of the genome-wide association analysis (GWAS) and traditional linkage mapping analysis. Linkage mapping was performed using 228 recombinant inbred lines (RILs), and a highly significant QTL that affected aflatoxin accumulation, qAA8, was mapped. This QTL spanned approximately 7 centi-Morgan (cM) on chromosome 8. The confidence interval was too large for positional cloning of the causal gene. To refine this QTL, GWAS was performed with 558,629 single nucleotide polymorphisms (SNPs) in an association population comprising 437 maize inbred lines. Twenty-five significantly associated SNPs were identified, most of which co-localised with qAA8 and explained 6.7% to 26.8% of the phenotypic variation observed. Based on the rapid linkage disequilibrium (LD) and the high density of SNPs in the association population, qAA8 was further localised to a smaller genomic region of approximately 1500 bp. A high-resolution map of the qAA8 region will be useful towards a marker-assisted selection (MAS) of A. flavus resistance and a characterisation of the causal gene. PMID:27598199

  7. Genetic Mapping of Laminaria japonica and L. longissima Using Amplified Fragment Length Polymorphism Markers in a "Two-Way Pseudo-Testcross" Strategy

    Institute of Scientific and Technical Information of China (English)

    Yuhui Li; Yingxia Yang; Jidong Liu; Xiuliang Wang; Tianxiang Gao; Delin Duan

    2007-01-01

    With a "two-way pseudo-testcross" mapping strategy, we applied the amplified fragment length polymorphism (AFLP) markers to construct two moderate density genetic linkage maps for Laminaria. The linkage maps were generated from the 60 progenies of the F1 cross family (Laminaria longissima Aresch. x L. japonica Miyabe) with twenty pairs of primer combinations. Of the 333 polymorphic loci scored in 60 progenies, 173 segregated in a 1:1ratio, corresponding to DNA polymorphisms heterozygous in a single parent, and the other 58 loci existing in both parents followed a 3:1 Mendelian segregation ratio. Among the loci with 1:1 segregating ratios, 79 loci were ordered in 14 linkage groups (648.6 cM) of the paternal map, and 72 loci were ordered in 14 linkage groups (601.9 cM) of the maternal map. The average density of loci was approximately 1 per 8 cM. To investigate the homologies between two parental maps, we used 58 loci segregated 3:1 for further analysis, and deduced one homologous linkage group. The linkage data developed in these maps will be useful for detecting loci-controlling commercially important traits for Laminaria.

  8. Novel genetic linkage of rat Sp6 mutation to Amelogenesis imperfecta

    Directory of Open Access Journals (Sweden)

    Muto Taro

    2012-06-01

    Full Text Available Abstract Background Amelogenesis imperfecta (AI is an inherited disorder characterized by abnormal formation of tooth enamel. Although several genes responsible for AI have been reported, not all causative genes for human AI have been identified to date. AMI rat has been reported as an autosomal recessive mutant with hypoplastic AI isolated from a colony of stroke-prone spontaneously hypertensive rat strain, but the causative gene has not yet been clarified. Through a genetic screen, we identified the causative gene of autosomal recessive AI in AMI and analyzed its role in amelogenesis. Methods cDNA sequencing of possible AI-candidate genes so far identified using total RNA of day 6 AMI rat molars identified a novel responsible mutation in specificity protein 6 (Sp6. Genetic linkage analysis was performed between Sp6 and AI phenotype in AMI. To understand a role of SP6 in AI, we generated the transgenic rats harboring Sp6 transgene in AMI (Ami/Ami + Tg. Histological analyses were performed using the thin sections of control rats, AMI, and Ami/Ami + Tg incisors in maxillae, respectively. Results We found the novel genetic linkage between a 2-bp insertional mutation of Sp6 gene and the AI phenotype in AMI rats. The position of mutation was located in the coding region of Sp6, which caused frameshift mutation and disruption of the third zinc finger domain of SP6 with 11 cryptic amino acid residues and a stop codon. Transfection studies showed that the mutant protein can be translated and localized in the nucleus in the same manner as the wild-type SP6 protein. When we introduced the CMV promoter-driven wild-type Sp6 transgene into AMI rats, the SP6 protein was ectopically expressed in the maturation stage of ameloblasts associated with the extended maturation stage and the shortened reduced stage without any other phenotypical changes. Conclusion We propose the addition of Sp6 mutation as a new molecular diagnostic criterion for the

  9. New Diversity Arrays Technology (DArT) markers for tetraploid oat (Avena magna Murphy et Terrell) provide the first complete oat linkage map and markers linked to domestication genes from hexaploid A. sativa L.

    Science.gov (United States)

    Oliver, R E; Jellen, E N; Ladizinsky, G; Korol, A B; Kilian, A; Beard, J L; Dumlupinar, Z; Wisniewski-Morehead, N H; Svedin, E; Coon, M; Redman, R R; Maughan, P J; Obert, D E; Jackson, E W

    2011-11-01

    Nutritional benefits of cultivated oat (Avena sativa L., 2n = 6x = 42, AACCDD) are well recognized; however, seed protein levels are modest and resources for genetic improvement are scarce. The wild tetraploid, A. magna Murphy et Terrell (syn A. maroccana Gdgr., 2n = 4x = 28, CCDD), which contains approximately 31% seed protein, was hybridized with cultivated oat to produce a domesticated A. magna. Wild and cultivated accessions were crossed to generate a recombinant inbred line (RIL) population. Although these materials could be used to develop domesticated, high-protein oat, mapping and quantitative trait loci introgression is hindered by a near absence of genetic markers. Objectives of this study were to develop high-throughput, A. magna-specific markers; generate a genetic linkage map based on the A. magna RIL population; and map genes controlling oat domestication. A Diversity Arrays Technology (DArT) array derived from 10 A. magna genotypes was used to generate 2,688 genome-specific probes. These, with 12,672 additional oat clones, produced 2,349 polymorphic markers, including 498 (21.2%) from A. magna arrays and 1,851 (78.8%) from other Avena libraries. Linkage analysis included 974 DArT markers, 26 microsatellites, 13 SNPs, and 4 phenotypic markers, and resulted in a 14-linkage-group map. Marker-to-marker correlation coefficient analysis allowed classification of shared markers as unique or redundant, and putative linkage-group-to-genome anchoring. Results of this study provide for the first time a collection of high-throughput tetraploid oat markers and a comprehensive map of the genome, providing insights to the genome ancestry of oat and affording a resource for study of oat domestication, gene transfer, and comparative genomics.

  10. Construction of Reference Chromosome-Scale Pseudomolecules for Potato: Integrating the Potato Genome with Genetic and Physical Maps

    Science.gov (United States)

    Sharma, Sanjeev Kumar; Bolser, Daniel; de Boer, Jan; Sønderkær, Mads; Amoros, Walter; Carboni, Martin Federico; D’Ambrosio, Juan Martín; de la Cruz, German; Di Genova, Alex; Douches, David S.; Eguiluz, Maria; Guo, Xiao; Guzman, Frank; Hackett, Christine A.; Hamilton, John P.; Li, Guangcun; Li, Ying; Lozano, Roberto; Maass, Alejandro; Marshall, David; Martinez, Diana; McLean, Karen; Mejía, Nilo; Milne, Linda; Munive, Susan; Nagy, Istvan; Ponce, Olga; Ramirez, Manuel; Simon, Reinhard; Thomson, Susan J.; Torres, Yerisf; Waugh, Robbie; Zhang, Zhonghua; Huang, Sanwen; Visser, Richard G. F.; Bachem, Christian W. B.; Sagredo, Boris; Feingold, Sergio E.; Orjeda, Gisella; Veilleux, Richard E.; Bonierbale, Merideth; Jacobs, Jeanne M. E.; Milbourne, Dan; Martin, David Michael Alan; Bryan, Glenn J.

    2013-01-01

    The genome of potato, a major global food crop, was recently sequenced. The work presented here details the integration of the potato reference genome (DM) with a new sequence-tagged site marker−based linkage map and other physical and genetic maps of potato and the closely related species tomato. Primary anchoring of the DM genome assembly was accomplished by the use of a diploid segregating population, which was genotyped with several types of molecular genetic markers to construct a new ~936 cM linkage map comprising 2469 marker loci. In silico anchoring approaches used genetic and physical maps from the diploid potato genotype RH89-039-16 (RH) and tomato. This combined approach has allowed 951 superscaffolds to be ordered into pseudomolecules corresponding to the 12 potato chromosomes. These pseudomolecules represent 674 Mb (~93%) of the 723 Mb genome assembly and 37,482 (~96%) of the 39,031 predicted genes. The superscaffold order and orientation within the pseudomolecules are closely collinear with independently constructed high density linkage maps. Comparisons between marker distribution and physical location reveal regions of greater and lesser recombination, as well as regions exhibiting significant segregation distortion. The work presented here has led to a greatly improved ordering of the potato reference genome superscaffolds into chromosomal “pseudomolecules”. PMID:24062527

  11. Pedigree with frontotemporal lobar degeneration – motor neuron disease and Tar DNA binding protein-43 positive neuropathology: genetic linkage to chromosome 9

    Directory of Open Access Journals (Sweden)

    Loy Clement T

    2008-08-01

    Full Text Available Abstract Background Frontotemporal lobar degeneration (FTLD represents a clinically, pathologically and genetically heterogenous neurodegenerative disorder, often complicated by neurological signs such as motor neuron-related limb weakness, spasticity and paralysis, parkinsonism and gait disturbances. Linkage to chromosome 9p had been reported for pedigrees with the neurodegenerative disorder, frontotemporal lobar degeneration (FTLD and motor neuron disease (MND. The objective in this study is to identify the genetic locus in a multi-generational Australian family with FTLD-MND. Methods Clinical review and standard neuropathological analysis of brain sections from affected pedigree members. Genome-wide scan using microsatellite markers and single nucleotide polymorphism fine mapping. Examination of candidate genes by direct DNA sequencing. Results Neuropathological examination revealed cytoplasmic deposition of the TDP-43 protein in three affected individuals. Moreover, we identify a family member with clinical Alzheimer's disease, and FTLD-Ubiquitin neuropathology. Genetic linkage and haplotype analyses, defined a critical region between markers D9S169 and D9S1845 on chromosome 9p21. Screening of all candidate genes within this region did not reveal any novel genetic alterations that co-segregate with disease haplotype, suggesting that one individual carrying a meiotic recombination may represent a phenocopy. Re-analysis of linkage data using the new affection status revealed a maximal two-point LOD score of 3.24 and a multipoint LOD score of 3.41 at marker D9S1817. This provides the highest reported LOD scores from a single FTLD-MND pedigree. Conclusion Our reported increase in the minimal disease region should inform other researchers that the chromosome 9 locus may be more telomeric than predicted by published recombination boundaries. Moreover, the existence of a family member with clinical Alzheimer's disease, and who shares the disease

  12. Genetic mapping and QTL analysis of agronomic traits in Indian Mucuna pruriens using an intraspecific F2 population

    Indian Academy of Sciences (India)

    S. Mahesh; M. Leelambika; Md Jaheer; A. M. Anithakumari; N. Sathyanarayana

    2016-03-01

    Mucuna pruriens is a well-recognized agricultural and horticultural crop with important medicinal use. However, antinutritional factors in seed and adverse morphological characters have negatively affected its cultivation. To elucidate the genetic control of agronomic traits, an intraspecific genetic linkage map of Indian M. pruriens has been developed based on amplified fragment length polymorphism (AFLP) markers using 200 F2 progenies derived from a cross between wild and cultivated genotypes. The resulting linkage map comprised 129 AFLP markers dispersed over 13 linkage groups spanning a total distance of 618.88 cM with an average marker interval of 4.79 cM. For the first time, three QTLs explaining about 6.05–14.77% of the corresponding total phenotypic variation for three quantitative (seed) traits and, eight QTLs explaining about 25.96% of the corresponding total phenotypic variation for three qualitative traits have been detected on four linkage groups. The map presented here will pave a way for mapping of genes/QTLs for the important agronomic and horticultural traits contrasting between the parents used in this study.

  13. Genetic linkage analysis of the lesser grain borer Rhyzopertha dominica identifies two loci that confer high-level resistance to the fumigant phosphine.

    Science.gov (United States)

    Schlipalius, David I; Cheng, Qiang; Reilly, Paul E B; Collins, Patrick J; Ebert, Paul R

    2002-01-01

    High levels of inheritable resistance to phosphine in Rhyzopertha dominica have recently been detected in Australia and in an effort to isolate the genes responsible for resistance we have used random amplified DNA fingerprinting (RAF) to produce a genetic linkage map of R. dominica. The map consists of 94 dominant DNA markers with an average distance between markers of 4.6 cM and defines nine linkage groups with a total recombination distance of 390.1 cM. We have identified two loci that are responsible for high-level resistance. One provides approximately 50x resistance to phosphine while the other provides 12.5x resistance and in combination, the two genes act synergistically to provide a resistance level 250x greater than that of fully susceptible beetles. The haploid genome size has been determined to be 4.76 x 10(8) bp, resulting in an average physical distance of 1.2 Mbp per map unit. No recombination has been observed between either of the two resistance loci and their adjacent DNA markers in a population of 44 fully resistant F5 individuals, which indicates that the genes are likely to reside within 0.91 cM (1.1 Mbp) of the DNA markers. PMID:12072472

  14. Genetic analysis and gene mapping of a rice few-tillering mutant in early backcross populations (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    TANG; Jiabin; (

    2001-01-01

    [1]Xu, Y. B., Shen, Z. T., Diallel analysis of tiller number at different growth stages in rice (Oryza sativa L.), Theoretical and Applied Genetics, 1991, 83(2): 243-249.[2]Wu, W. R., Li, W. M., Tang, D. Z. et al., Time-related mapping of quantitative trait loci underlying tiller number in rice, Genetics, 1999, (151): 297-303.[3]Wu, P., Zhang, G ., Huang, N., Identification of QTLs controlling quantitative characters in rice using RFLP markers, Euphytica, 1996, 89(3): 349-354.[4]Khush, G . S., Breaking the yield frontier of rice, GeoJournal, 1995, 35(3): 329-332.[5]Chen, X., Themnykh, S., Xu, Y. et al., Development of microsatellite framework providing genome-wide coverage in rice (Oryzae sativa L.), Theoretical and Applied Genetics, 1997, 95(4): 553-567.[6]Panaud, O., Chen, X., McCouch, S. R. et al., Development of microsatellite markers and characterization of simple sequence length polymorphisms (SSLPs) in rice (Oryzae sativa L.), Molecular and General Genetics, 1996, (252): 597-607.[7]McCouth, S. R., Kochert, G., Yu, Z. H. et al., Molecular mapping of rice chromosomes, Theoretical and Applied Genetics, 1988, 76: 815-829.[8]Harushima, Y., Yano, M., Shomura, A. et al., A high-density rice genetic linkage map with 2275 markers using a single F2 population, Genetics, 1998, 148: 479-494.[9]Lander, E. S. et al., Mapmaker: An interactive computer for construction primary genetics linkage maps of experimental and natural populations, Genomics, 1987, (1): 174-182.[10]Kinoshita, T., Report of committee on gene symbolization, nomenclature and linkage groups, Rice Genetic Newsletter, 1995, (12): 9-153.

  15. High resolution genetic map of the adenomatous polyposis coli gene (APC) region

    Energy Technology Data Exchange (ETDEWEB)

    Olschwang, S.; Laurent-Puig, P.; Melot, T. [Institut Curie, Paris (France)

    1995-05-08

    Familial adenomatous polyposis coli (APC) is a dominantly inherited colorectal cancer susceptibility disease caused by mutation in a gene called APC located on chromosome 5q21. Presymptomatic diagnosis of this condition is recommended because it enables restriction of the efficient but demanding prevention program to those relatives that are genetically affected. The large size of the APC gene makes the direct search for the casual alteration difficult to implement in routine diagnostic laboratories. Because APC appears to be genetically homogeneous with alteration in a single locus causing the disease, cosegregation analysis may represent an alternative efficient method for presymptomatic diagnosis. However, the reliability of the risk estimation by linkage analysis in APC families is hampered by the lack of a short range genetic map of the APC locus. A combined approach including genotyping of 65 APC families, analysis of the CEPH database, and complementary typing of both APC and CEPH families has made it possible to derive the following genetic map: Centromere-[D5S82-D5S49]-0.02-D5S122-0.01-D5S136-0.01-D5S135-0.02-[APC-D5S346-MCC]-0.04-[D5S81-D5S64]-Telomere. This order, which differs from previously proposed genetic maps, is fully compatible with recent physical mapping data. These data should contribute to increase the reliability of the presymptomatic test for APC. 42 refs., 1 fig., 3 tabs.

  16. Fast and cost-effective genetic mapping in apple using next-generation sequencing.

    Science.gov (United States)

    Gardner, Kyle M; Brown, Patrick; Cooke, Thomas F; Cann, Scott; Costa, Fabrizio; Bustamante, Carlos; Velasco, Riccardo; Troggio, Michela; Myles, Sean

    2014-07-16

    Next-generation DNA sequencing (NGS) produces vast amounts of DNA sequence data, but it is not specifically designed to generate data suitable for genetic mapping. Recently developed DNA library preparation methods for NGS have helped solve this problem, however, by combining the use of reduced representation libraries with DNA sample barcoding to generate genome-wide genotype data from a common set of genetic markers across a large number of samples. Here we use such a method, called genotyping-by-sequencing (GBS), to produce a data set for genetic mapping in an F1 population of apples (Malus × domestica) segregating for skin color. We show that GBS produces a relatively large, but extremely sparse, genotype matrix: over 270,000 SNPs were discovered but most SNPs have too much missing data across samples to be useful for genetic mapping. After filtering for genotype quality and missing data, only 6% of the 85 million DNA sequence reads contributed to useful genotype calls. Despite this limitation, using existing software and a set of simple heuristics, we generated a final genotype matrix containing 3967 SNPs from 89 DNA samples from a single lane of Illumina HiSeq and used it to create a saturated genetic linkage map and to identify a known QTL underlying apple skin color. We therefore demonstrate that GBS is a cost-effective method for generating genome-wide SNP data suitable for genetic mapping in a highly diverse and heterozygous agricultural species. We anticipate future improvements to the GBS analysis pipeline presented here that will enhance the utility of next-generation DNA sequence data for the purposes of genetic mapping across diverse species.

  17. Positive replication and linkage disequilibrium mapping of the Chromosome 21q22.1 malaria susceptibility locus

    Science.gov (United States)

    Khor, Chiea C.; Vannberg, Fredrik O.; Chapman, Stephen J.; Walley, Andrew; Aucan, Christophe; Loke, Hsin; White, Nicholas J.; Peto, Tim; Khor, Lih K.; Kwiatkowski, Dominic; Day, Nick; Scott, Anthony; Berkley, James A.; Marsh, Kevin; Peshu, Norbert; Maitland, Kathryn; Williams, Thomas N.; Hill, Adrian V. S.

    2009-01-01

    Four cytokine receptor genes are located on Chr21q22.11, encoding the α and β subunits of the interferon alpha receptor (IFNAR1 and IFNAR2), the β subunit of the interleukin 10 receptor (IL10RB), and the second subunit of the interferon gamma receptor (IFNGR2). We previously reported that two variants in IFNAR1 were associated with susceptibility to malaria in Gambians. We now present an extensive fine-scale mapping of the associated region utilizing 45 additional genetic markers obtained from public databases and by sequencing a 44kb region in and around the IFNAR1 gene in 24 Gambian children (12 cases/ 12 controls). Within the IFNAR1 gene a newly studied C→G single nucleotide polymorphism (IFNAR1 272354c-g) at position −576 relative to the transcription start was found to be more strongly associated with susceptibility to severe malaria. Association was observed in three populations: in Gambian (P=0.002), Kenyan (P=0.022) and Vietnamese (P=0.005) case control studies. When all three studies were combined, using the Mantel-Haenszel test, the presence of IFNAR1 −576G was associated with a substantially elevated risk of severe malaria (N=2444, OR=1.38, 95%CI: 1.17-1.64; P=1.7×10−4). This study builds on previous work to further highlight the importance of the type I interferon pathway in malaria susceptibility and illustrates the utility of typing SNPs within regions of high linkage disequilibrium in multiple populations to confirm initial positive associations. PMID:17703179

  18. Genotyping by Sequencing for SNP-Based Linkage Map Construction and QTL Analysis of Chilling Requirement and Bloom Date in Peach [Prunus persica (L. Batsch].

    Directory of Open Access Journals (Sweden)

    Douglas Gary Bielenberg

    Full Text Available Low-cost, high throughput genotyping methods are crucial to marker discovery and marker-assisted breeding efforts, but have not been available for many 'specialty crops' such as fruit and nut trees. Here we apply the Genotyping-By-Sequencing (GBS method developed for cereals to the discovery of single nucleotide polymorphisms (SNPs in a peach F2 mapping population. Peach is a genetic and genomic model within the Rosaceae and will provide a template for the use of this method with other members of this family. Our F2 mapping population of 57 genotypes segregates for bloom time (BD and chilling requirement (CR and we have extensively phenotyped this population. The population derives from a selfed F1 progeny of a cross between 'Hakuho' (high CR and 'UFGold' (low CR. We were able to successfully employ GBS and the TASSEL GBS pipeline without modification of the original methodology using the ApeKI restriction enzyme and multiplexing at an equivalent of 96 samples per Illumina HiSeq 2000 lane. We obtained hundreds of SNP markers which were then used to construct a genetic linkage map and identify quantitative trait loci (QTL for BD and CR.

  19. Constructing a Linkage Map of Upland Cotton(Gossypium hirsutum L.) Using RFLP, RAPD and SSR Markers%利用RFLP、SSR和RAPD标记构建陆地棉分子标记连锁图

    Institute of Scientific and Technical Information of China (English)

    左开井; 孙济中; 张献龙; 聂以春; 刘金兰; 冯纯大

    2000-01-01

    @@ Molecular marker linkage map is important for gene mapping, map-based cloni ng and molecular marker-assisted selection. In rice[1], oilseed rape[2] and corn[3], seve ral high-den sity molecular marker linkage maps were constructed and employed in mapping dise ase-resistant genes, insect-resistant genes and agronomic traits' QTLs.

  20. Construction of a genetic map with SRAP markers and localization of the gene responsible for the first-flower-node trait in cucumber ( Cucumis sativus L. )

    Institute of Scientific and Technical Information of China (English)

    PAN Junsong; WANG Gang; LI Xiaozun; HE Huanle; WU Aizhong; CAI Run

    2005-01-01

    With an F2 population from the cross of two cucumber inbred lines, S06 and S52, sequence-related amplified polymorphism (SRAP) was used to construct a genetic linkage map in cucumber (Cucumis sativus L. ). Sixty-four SRAP primer combinations generated 108 polymorphic bands in the F2 population analysis. The average of polymorphic bands produced by one primer pair was 1.5,and the maximum was 5. Using Mapmaker 3.0, a linkage map was constructed, which consisted of 77 SRAP markers distributed in nine linkage groups (LOD≥3.0) and spanned 1114.2 cM with an average interval of 14.5 cM between markers. The gene for the first-flowernode trait, termed ffn, was mapped to linkage group IX, flanked by DC1EM5 and ME7EM2A at 10.3 cM and 12.1 cM distance, respectively.

  1. Mapping Aboveground Biomass in the Amazon Basin: Exploring Sensors, Scales, and Strategies for Optimal Data Linkage

    Science.gov (United States)

    Walker, W. S.; Baccini, A.

    2013-05-01

    Information on the distribution and density of carbon in tropical forests is critical to decision-making on a host of globally significant issues ranging from climate stabilization and biodiversity conservation to poverty reduction and human health. Encouraged by recent progress at both the international and jurisdictional levels on the design of incentive-based policy mechanisms to compensate tropical nations for maintaining their forests intact, governments throughout the tropics are moving with urgency to implement robust national and sub-national forest monitoring systems for operationally tracking and reporting on changes in forest cover and associated carbon stocks. Monitoring systems will be required to produce results that are accurate, consistent, complete, transparent, and comparable at sub-national to pantropical scales, and satellite-based remote sensing supported by field observations is widely-accepted as the most objective and cost-effective solution. The effectiveness of any system for large-area forest monitoring will necessarily depend on the capacity of current and near-future Earth observation satellites to provide information that meets the requirements of developing monitoring protocols. However,