WorldWideScience

Sample records for androgenesis

  1. Fine structure of plastids during androgenesis in Hordeum vulgare L.

    OpenAIRE

    Fortunat Młodzianowski; Krystyna Idzikowska

    2014-01-01

    The fine structure of plastids was studied in the course of androgenesis in in the pollen of Hordeum vulgare L. It was found that these organelles occur in all stages of androgenesis. Their structure was simple and was frequently manifested on the cross section only by the presence of the envelope and matrix of different degree of density. Single thylakoids, nucleoid-like regions and starch grains were, however, also noted. The structure of plastids in embryoids formed from microspores of bar...

  2. Pathways to doubled haploidy: chromosome doubling during androgenesis.

    Science.gov (United States)

    Seguí-Simarro, J M; Nuez, F

    2008-01-01

    Production of doubled haploid (DH) plants through androgenesis induction is a promising and convenient alternative to conventional selfing techniques for the generation of pure lines for breeding programs. This process comprises two main steps: induction of androgenesis and duplication of the haploid genome. Such duplication is sometimes indirectly induced by the treatments used to promote androgenic development. But usually, an additional step of direct chromosome doubling must be included in the protocol. Duplication of the haploid genome of androgenic individuals has been thought to occur through three mechanisms: endoreduplication, nuclear fusion and c-mitosis. In this review we will revise and analyze the evidences supporting each of the proposed mechanisms and their relevance during androgenesis induction, embryo/callus development and plant regeneration. Special attention will be devoted to nuclear fusion, whose evidences are accumulating in the last years.

  3. Differential androgenesis in gamma irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jihyang; Yoon, Yongdal [Hanyang Univ., Seoul (Korea, Republic of); Kim, Jin Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2002-07-01

    The Leydig cells of the testis account for at least 75% of the total testosterone produced in the normal adult male. Whereas the production of estrogen from androgen is catalyzed by aromatase cytochrome P450, which is found in many tissues, including gonad, brain, adipose tissue, bone, and heart. The gamma-irradiation causes the impairment of spermatogenesis and steroidogenesis in male mice. The present study was performed to analyze changes in testosterone concentrations and expression of steroidogenic enzyme of mice after whole body gamma-irradiation. Eight-week-old male ICR mice were irradiated with 6.5 or 10 Gy. At days 1, 2, 3, 4, and 5 after irradiation, testes were removed and processed for paraffin sections and isolation of mRNA. We calculated the gonad index from body and testis weight, and checked the testis volume. Hormonal analysis was performed by means of radioimmunoassay (RIA) in serum and intratesticular fluid. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was used to evaluate the expression kinetics of the apoptotic gene and the cytochrome P450 aromatase gene after irradiation. In gamma-irradiated mice, the body weight reduced in comparison to that of the control group. Therefore, gonad indices increased. The testosterone concentrations in serum and intratesticular fluid were significantly reduced. RT- PCR data represented that the expression of Fas, Fas ligand, and aromatase cytochrome P450 showed the specific patterns against control groups. These results indicated that gamma- irradiation of adult mice induced the alteration of androgenesis and suggested that might counteract the spermatogenesis.

  4. Fine structure of plastids during androgenesis in Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Fortunat Młodzianowski

    2014-01-01

    Full Text Available The fine structure of plastids was studied in the course of androgenesis in in the pollen of Hordeum vulgare L. It was found that these organelles occur in all stages of androgenesis. Their structure was simple and was frequently manifested on the cross section only by the presence of the envelope and matrix of different degree of density. Single thylakoids, nucleoid-like regions and starch grains were, however, also noted. The structure of plastids in embryoids formed from microspores of barley was compared with embryos developed from fertilized egg cell, and we did not found any fundamental differences between them. However, only plastid ribosomes were difficult to identify on ultrathin sections in embryoids and in the embryos.

  5. Androgenesis: a review through the study of the selfish shellfish Corbicula spp.

    OpenAIRE

    Pigneur, L-M; Hedtke, S M; Etoundi, E; Van Doninck, K.

    2012-01-01

    Among the asexual reproductive modes, androgenesis is probably one of the most astonishing and least studied mechanisms. In this ‘paternal monopolization', the maternal nuclear genome fails to participate in zygote development and offspring are paternal nuclear clones. Obligate androgenesis is known in only a few organisms, including multiple species of clam in the genus Corbicula. Corbicula is a good system to review the evolutionary consequences of this ‘all-male asexuality' because the cyt...

  6. cDNA array analysis of stress-induced gene expression in barley androgenesis

    NARCIS (Netherlands)

    Maraschin, S.D.F.; Caspers, M.; Potokina, E.; Wülfert, F.; Graner, A.; Spaink, H.P.; Wang, M.

    2006-01-01

    Different aspects of androgenesis induction have been studied in detail, but little is known about the molecular mechanisms associated with this developmental switch. We have employed macroarrays containing 1421 expressed sequence tags covering the early stages of barley zygotic embryogenesis to com

  7. Induced artificial androgenesis in common tench, Tinca tinca (L., using common carp and common bream eggs

    Directory of Open Access Journals (Sweden)

    Dariusz Kucharczyk

    2014-03-01

    Full Text Available This study presents artificial induction using tench eggs, Tinca tinca (L., of androgenetic origin. The oocytes taken from common bream, Abramis brama (L. and common carp, Cyprinus carpio L. were genetically inactivated using UV irradiation and then inseminated using tench spermatozoa. Androgenetic origin (haploid or diploid embryos was checked using a recessive colour (blond and morphological markers. The percentage of hatched embryos in all experimental groups was much lower than in the control groups. All haploid embryos showed morphological abnormalities, which were recorded as haploid syndrome (stunted body, poorly formed retina, etc.. The optimal dose of UV irradiation of common bream and common carp eggs was 3456 J m–2. At this dose, almost 100% of haploid embryos were produced at a hatching rate of over 6%. Lower UV-ray doses affected abnormal embryo development. The highest yield of tench androgenesis (about 2% was noted when eggs were exposed to thermal shock 30 min after egg activation.

  8. Androgenesis in chickpea: Anther culture and expressed sequence tags derived annotation

    DEFF Research Database (Denmark)

    Panchangam, Sameera Sastry; Mallikarjuna, Nalini; Gaur, Pooran M.;

    2014-01-01

    Double haploid technique is not routinely used in legume breeding programs, though recent publications report haploid plants via anther culture in chickpea (Cicer arietinum L.). The focus of this study was to develop an efficient and reproducible protocol for the production of double haploids...... with the application of multiple stress pre-treatments such as centrifugation and osmotic shock for genotypes of interest in chickpea for their direct use in breeding programs. Four genotypes, ICC 4958, WR315, ICCV 95423 and Arearti were tested for anther culture experiments. The yield was shown to be consistent...... with 3-5 nucleate microspores and 2-7 celled structures with no further growth. To gain a further insight into the molecular mechanism underlying the switch from microsporogenesis to androgenesis, bioinformatics tools were employed. The challenges on the roles of such genes were reviewed while an attempt...

  9. Cold-shock eliminates female nucleus in fertilized eggs to induce androgenesis in the loach (Misgurnus anguillicaudatus, a teleost fish

    Directory of Open Access Journals (Sweden)

    Morishima Kagayaki

    2011-11-01

    Full Text Available Abstract Background Androgenesis (all-male inheritance is generally induced by means of irradiating the eggs to inactivate the maternal genome, followed by fertilization with normal sperm. In fish, the conventional technique for induced androgenesis has been applied for rapid fixation to traits, recovery of cryopreserved genotypes, sex-control, etc. A new method of androgenesis that eliminates the need to irradiate the egg was proposed using the loach, Misgurnus anguillicaudatus (a teleost fish. Results When the eggs of wild-type females were fertilized with sperm of albino or orange phenotype males and cold-shocked at 0 to 3°C for 60 min duration just after fertilization, generally more than 30% (with a peak of 100% of the hatched progeny were androgenotes. While a few of them were the normal diploid, most of them turned out to be abnormal haploid. All-male inheritance was verified by the expression of the recessive color trait (albino or orange and microsatellite genotypes comprising only paternally derived alleles. Nuclear behavior after the cold-shock treatment was traced by microscopic observation of DAPI (4'6-diamidino-2-phenylindole-stained samples and hematoxylin-eosin stained histological sections, and the extrusion of egg (maternal nucleus was observed in eggs treated in the optimum timing. Conclusion In this paper, we demonstrate that cold-shock treatment (at 0 and 3°C of loach eggs for 60 min just after fertilization successfully induces androgenetic haploid development. The most likely mechanism of cold-shock induced androgenesis is an elimination of the egg nucleus together along with the second polar body and subsequent development of a decondensed sperm nucleus or male pronucleus.

  10. Spontaneous polyploidy, gynogenesis and androgenesis in second generation (F2 ) koi Cyprinus carpio × goldfish Carassius auratus hybrids.

    Science.gov (United States)

    Delomas, T A; Gomelsky, B; Anil, A; Schneider, K J; Warner, J L

    2017-01-01

    The objective of this study was to characterize the genetics of second generation (F2 ) koi Cyprinus carpio × goldfish Carassius auratus hybrids. Spermatozoa produced by a novel, fertile F1 male were found to be diploid by flow-cytometric analysis. Backcross (F1 female × C. carpio male and C. carpio female × F1 male) juveniles were triploid, confirming that female and male F1 hybrids both produced diploid gametes. The vast majority of surviving F2 juveniles was diploid and small proportions were aneuploid (2·1n-2·3n and 3·1n-3·9n), triploid (3n) and tetraploid (4n). Microsatellite genotyping showed that F2 diploids repeated either the complete maternal or the complete paternal genotype. Fish with the maternal genotype were female and fish with the paternal genotype were male. This demonstrates that F2 diploids were the result of spontaneous gynogenesis and spontaneous androgenesis. Analysis of microsatellite inheritance and the sex ratio in F2 crosses showed that spontaneous gynogenesis and androgenesis did not always occur in equal proportions. One cross was found to have an approximate equal number of androgenetic and gynogenetic offspring while in several other crosses spontaneous androgenesis was found to occur more frequently than spontaneous gynogenesis.

  11. The formation of improved tetraploid population of red crucian carp × common carp hybrids by androgenesis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bisexual fertile diploid androgenetic individuals (A0) (2n=100) were formed by androgenesis. In this way, the diploid spermatozoa from male allotetraploid hybrids (AT) (4n=200) of red crucian carp (Carassius auratus red var.) (♀) × common carp (Cyprinus carpio L.) (♂) were used to fertilize the UV-treated haploid eggs of goldfish (Carassius auratus), and living androgenetic diploid fish were developed. The A0 became sexually mature at the age of 2 years, and they fertilized with each other to form their offspring (A1). In this study, we observed the chromosomal number, gonadal structure and appearance of A1 fish. The results are as follows: (1) In A1, there were 85% tetraploids (A1-4n), 10% triploids (A1-3n) and 5% diploids (A1-2n), suggesting that diploid A0 could produce diploid gametes. It was concluded that the formation of diploid gametes generated from diploid A0 was probably related to the mechanism of pre-meiotic endoreduplication. (2) Among A1, only A1-4n possessed normal ovaries and testes. The mature males of A1-4n produced white semen. Under the electron microscope, the head of diploid sperm generated by A1-4n was bigger than that of haploid sperm generated by red crucian carp. In the testes of the A1-4n, there were many mature normal spermatozoa with a head bearing plasma membrane and a tail having the typical structure of "9+2" microtubules. Between the head and the tail, there were some mitochondria. The ovaries of A1-4n developed well and mainly contained Ⅱ, Ⅲ and Ⅳ-stage oocytes. The Ⅳ-stage oocytes were surrounded by inner and outer follicular cells. The micropyle was observed on the oolemma of follicular cells. There were abundant yolks and plenty of endoplasmic reticulum in the cytoplasm of Ⅳ-stage oocytes. Because A1-2n and A1-3n were distant crossing diploid hybrids and triploid hybrids respectively, they possessed abnormal gonads, and no mature semen and eggs were observed. (3) Compared with allotetraploids, the A1-4n fish not

  12. The formation of improved tetraploid population of red crucian carp x common carp hybrids by androgenesis.

    Science.gov (United States)

    Duan, Wei; Qin, QinBo; Chen, Song; Liu, ShaoJun; Wang, Jing; Zhang, Chun; Sun, YuanDong; Liu, Yun

    2007-12-01

    Bisexual fertile diploid androgenetic individuals (A(0)) (2n=100) were formed by androgenesis. In this way, the diploid spermatozoa from male allotetraploid hybrids (AT) (4n=200) of red crucian carp (Carassius auratus red var.) (female) x common carp (Cyprinus carpio L.) (male) were used to fertilize the UV-treated haploid eggs of goldfish (Carassius auratus), and living androgenetic diploid fish were developed. The A(0) became sexually mature at the age of 2 years, and they fertilized with each other to form their offspring (A(1)). In this study, we observed the chromosomal number, gonadal structure and appearance of A(1) fish. The results are as follows: (1) In A(1), there were 85% tetraploids (A(1)-4n), 10% triploids (A(1)-3n) and 5% diploids (A(1)-2n), suggesting that diploid A(0) could produce diploid gametes. It was concluded that the formation of diploid gametes generated from diploid A(0) was probably related to the mechanism of pre-meiotic endoreduplication. (2) Among A(1), only A(1)-4n possessed normal ovaries and testes. The mature males of A1-4n produced white semen. Under the electron microscope, the head of diploid sperm generated by A(1)-4n was bigger than that of haploid sperm generated by red crucian carp. In the testes of the A(1)-4n, there were many mature normal spermatozoa with a head bearing plasma membrane and a tail having the typical structure of "9+2" microtubules. Between the head and the tail, there were some mitochondria. The ovaries of A(1)-4n developed well and mainly contained II, III and IV-stage oocytes. The IV-stage oocytes were surrounded by inner and outer follicular cells. The micropyle was observed on the oolemma of follicular cells. There were abundant yolks and plenty of endoplasmic reticulum in the cytoplasm of IV-stage oocytes. Because A(1)-2n and A(1)-3n were distant crossing diploid hybrids and triploid hybrids respectively, they possessed abnormal gonads, and no mature semen and eggs were observed. (3) Compared with

  13. A novel nucleo-cytoplasmic hybrid clone formed via androgenesis in polyploid gibel carp

    Directory of Open Access Journals (Sweden)

    Zhou Li

    2011-03-01

    Full Text Available Abstract Background Unisexual vertebrates have been demonstrated to reproduce by gynogenesis, hybridogenesis, parthenogenesis, or kleptogenesis, however, it is uncertain how the reproduction mode contributes to the clonal diversity. Recently, polyploid gibel carp has been revealed to possess coexisting dual modes of unisexual gynogenesis and sexual reproduction and to have numerous various clones. Using sexual reproduction mating between clone D female and clone A male and subsequent 7 generation multiplying of unisexual gynogenesis, we have created a novel clone strain with more than several hundred millions of individuals. Here, we attempt to identify genetic background of the novel clone and to explore the significant implication for clonal diversity contribution. Methods Several nuclear genome markers and one cytoplasmic marker, the mitochondrial genome sequence, were used to identify the genetic organization of the randomly sampled individuals from different generations of the novel clone. Results Chromosome number, Cot-1 repetitive DNA banded karyotype, microsatellite patterns, AFLP profiles and transferrin alleles uniformly indicated that nuclear genome of the novel clone is identical to that of clone A, and significantly different from that of clone D. However, the cytoplasmic marker, its complete mtDNA genome sequence, is same to that of clone D, and different from that of clone A. Conclusions The present data indicate that the novel clone is a nucleo-cytoplasmic hybrid between the known clones A and D, because it originates from the offspring of gonochoristic sexual reproduction mating between clone D female and clone A male, and contains an entire nuclear genome from the paternal clone A and a mtDNA genome (cytoplasm from the maternal clone D. It is suggested to arise via androgenesis by a mechanism of ploidy doubling of clone A sperm in clone D ooplasm through inhibiting the first mitotic division. Significantly, the selected nucleo

  14. [Effect of rye chromosomes on features of androgenesis in wheat-rye substituted lines of Triticum aestivum L. sort Saratovskaya 29/Secale cerale L. sort Onokhoiskaia and Triticale].

    Science.gov (United States)

    Dobrovolskaia, O B; Pershina, L A; Kravtsova, L A; Silkova, O G; Shchapova, A I

    2001-05-01

    The characteristic features of androgenesis in six wheat-rye substitution lines Triticum aestivum L. (cv. Saratovskaya 29)/Secale cereale L. (cv. Onokhoiskaya) and triticale (2n = 56) using anther culture at different concentrations of 2,4-D in the growth medium were studied. Under variable cultivation conditions, the significant effect of genotypic diversity on the variability of such androgenesis parameters as the frequency of productive anthers, the frequency of embryoid formation, and the frequency of total regenerated plantlets, was shown. It was demonstrated that chromosomes 1R, 3R, and 7R stimulated the formation of androgenous embryoids, while chromosome 5R produced an opposite effect. In triticale and substitution lines, the regeneration ability of androgenous embryoids induced by elevated 2,4-D concentrations was inhibited. Chromosome 1R of the Onokhoiskaya cultivar was suggested to contain genes suppressing regeneration of green plantlets, while chromosome 3R, conversely, stimulated their formation. Chromosomes 1R, 2R, 3R, and 7R of the Onokhoiskaya cultivar did not inhibit the spontaneous formation of androgenous hexaploids in the substitution lines.

  15. Research Progress in Androgenesis and Haploid Breeding of Gramineous Forage and Turfgrass Plants%禾本科牧草和草坪草雄核发育与单倍体育种研究进展

    Institute of Scientific and Technical Information of China (English)

    赵永钦; 吴新新; 李蔚; 李仁; 史文君; 郭仰东

    2012-01-01

    禾本科牧草与草坪草在农业可持续发展、城市绿化和生态环境保护方面起着至关重要的作用.近年来,随着生物技术的发展,国内外在牧草及草坪草雄核发育与单倍体育种研究方面取得了较大进展.该文在归纳总结该领域研究成果的基础上,对影响禾本科牧草及草坪草雄核发育与单倍体育种的几个主要因素进行了探讨.大量研究结果表明,供试材料的基因型是影响培养效率的最主要因素.小孢子发育到单核中期至晚期时有利于提高培养效率.培养前花药经过低温和甘露醇等预处理不但可以提高愈伤组织的诱导效率,还可提高愈伤组织的质量.适宜的激素种类和配比也是影响培养成败的关键因素.同时,总结了雄核发育再生植株的倍性鉴定方法和加倍技术,对单倍体育种技术在禾本科牧草及草坪草育种中的应用前景进行了展望.%Gramineous forage and turfgrass are critical to sustainable agriculture and contribute extensively to urban landscaping and ecological protection. In recent years, with the rapid development of biotechnology, significant progress has been made in androgenesis and haploid breeding research of gramineous forage and turfgrasses. This review describes the development of androgenesis systems for gramineous forage and turfgrass and summarizes the latest progress of some important influencing factors on androgenesis and haploid breeding. The genotype of experimental materials is the main factor influencing androgenesis efficiency. The optimal stage for efficient androgenesis of microspore development is between middle and late uninucleate. The ratio and quality of callus induction were improved after anthers were pretreated with low temperature or mannitol. Suitable varieties and ratios of hormone are also the key factors in androgenesis. We summarize the methods of ploidy determination and techniques of chromosome doubling and point out prospects

  16. Mitochondria during androgenesis in Hordeum vulgare

    Directory of Open Access Journals (Sweden)

    Krystyna Idzikowska

    2014-01-01

    Full Text Available Different number of mitochondria of varying structure was observed in particular stages of the development of barley (Hordeum vulgare microspores, stimulated by the in vitro culture to form embryoids. This variability was reflected in different shape of sections, different ratio between total area of mitochondria profiles and area of cytoplasm sections, varying number of cristae, and different density of the matrix. Within the cristae of some mitochondria crystalline inclusions were observed. Mitochondria divided by a contraction. In the matrix of some mitochondria spheric bodies were formed. They were surrounded by one or two membranes. It is suggested that the bi-membrane forms constituted promitochandria, whereas unimembrane forms could constitute promicrobodies.

  17. Androgenesis in Citrus aurantifolia (Christm.) swingle.

    Science.gov (United States)

    Chaturvedi, H C; Sharma, A K

    1985-07-01

    Embryoids were differentiated from anthers of C. aurantifolia which were first floated on a modified Murashige and Skoog's liquid medium supplemented with 0.5 mg/l N(6)-benzylaminopurine and 1 mg/l indole-3-acetic acid for 20-30 d, followed by 30 d culture in semisolid Schenk and Hildebrandt's medium having the same growth hormones. Embryoids originated from within the anther lobes. Initially, a few embryoids were formed by each anther; later, they multiplied rapidly by the production of new embryoids from the hypocotyl and cotyledon portions of the original embryoids. The embryoids could develop into plantlets, which were all diploid (2n=18). The androgenic plants grew normally in soil.

  18. Pollen dimorphism and androgenesis in Hordeum vulgare

    Directory of Open Access Journals (Sweden)

    Krystyna Idzikowska

    2014-01-01

    Full Text Available Dimorphism of binucleate pollen grains of Hordeum vulgare has been confirmed. It is considered, however, in contrast to the accepted opinions, that some of the large pollen grains with dense cytoplasm lying close to the tapetum are the outset forms for embryoids, and not the small pollen grains with scarce cytoplasm lying in the pollen sac centre.

  19. Androgenesis in anther culture of Lithuanian spring barley cultivars

    OpenAIRE

    Asakavičiūtė, Rita; Pašakinskienė, Izolda

    2006-01-01

    The method of anther culture was used for the production of doubled haploids in Lithuanian spring barley cultivars. Two methods, (i) regeneration from callus (Szarjeko’s method) and (ii) direct regeneration from embryoids (Caredda’s method) were applied to determine the androgenic potential according to the green regenerant yield and other morphogenetic factors. Green double haploid regenerants were obtained in four Lithuanian spring barley cultivars (‘Aura’, ‘Aidas’, ‘Alsa’ and ‘Auksiniai’) ...

  20. Pueraria tuberosa DC Extract Improves Androgenesis and Sexual Behavior via FSH LH Cascade

    Directory of Open Access Journals (Sweden)

    Nagendra Singh Chauhan

    2013-01-01

    Full Text Available The aim of this study was to investigate the effects of ethanolic extract of Pueraria tuberosa (PT on sexual behaviour and androgenic activity. Male albino rats were divided into four groups of six animals each: control group 1 (2% acacia solution, PT-treated group 2 (50 mg/Kg, PT-treated group 3 (100 mg/Kg, and PT-treated group 4 (150 mg/Kg. Sexual behavior of male rats in the presence of a female rat was recorded. The treated groups were evaluated for sexual parameters. The extract was characterized using LC-MS. The effect of treatment on anabolic and weight of secondary sexual organs was determined. The histological changes in section of testis and epididymis after treatment were observed. Sperm count in epididymis and fructose content in seminal vesicles were also measured. Levels of hormones like FSH, LH, and T were determined. A dose-dependent increase in sexual behaviors was evidenced in the animals of extract treated groups. Increase in testis weight was recorded in PT. At the highest dose PT also affects the hormones level. The four compounds namely puerarin, daidzein, biochanin-A and formononetin were identified in ethanolic extract using LC-MS. It concluded that PT extract possesses androgenic effect and it significantly increased the sexual behaviour and hormones level.

  1. Androgenesis Induced in Nicotiana alata and the Effect of Gamma Irradiation

    Directory of Open Access Journals (Sweden)

    Ayman EL-FIKI

    2015-03-01

    Full Text Available Nicotiana alata anthers cultured on different modified media based on MS, MT and N were used to obtain haploid plants through direct and indirect ways. The haploid plants resulting on MS medium ranged from 52% - 80%, on MT medium ranged from 32% - 52% and on N medium ranged from 28% - 44%. Accordingly, the best medium used for haploid induction was MS supplemented with 0.2 mgl-l NAA + 0.5 mgl-l KIN. On the other hand, MS medium supplemented with 0.4 mgl-l NAA + 0.5 mgl-l KIN or 1.0 mgl-l BAP + 0.5 mgl-l NAA were the best mediums for callus induction and plant regeneration, respectively. Morphologically, the leaf size, stem highest and diameter, flower size and diameter, anther length and number were about 67% of the diploid plants growth. Irradiated anthers with doses of 0, 2.5, 5, 7.5, 10, 15, 20 and 25 Gy caused reducing the number of haploid plants with increasing gamma radiation dose. For the haploid plants irradiated with same doses, the mortality percentage of bud survival was increasing with increasing gamma radiation dose. The irradiated callus with doses of 0, 5, 10, 15 and 20 Gy was affected negatively on growth rate and morphology. Proline content in irradiated plantlets increased with increasing gamma radiation dose. As well, total soluble protein content was increased with gamma irradiation up to 10 Gy. However, the higher doses caused a severe decrease of total soluble proteins. The production of proline and total soluble proteins in haploid plants were 48.6% and 69.5%, respectively comparing with diploid plants.

  2. Clonal reproduction with androgenesis and somatic recombination: the case of the ant Cardiocondyla kagutsuchi

    Science.gov (United States)

    Okita, Ichiro; Tsuchida, Koji

    2016-04-01

    In haplodiploid insects such as ants, male sexuals develop from unfertilised haploid eggs, while female sexuals and workers develop from fertilized diploid eggs. However, some ant species do not exchange their gene pool between sexes; both male and female sexuals are clonally produced, while workers are sexually produced. To date, three ant species, Wasmannia auropunctata, Vollenhovia emeryi, and Paratrechina longicornis, have been reported to reproduce using such reproductive systems. In this study, we reveal that in one lineage of the ant Cardiocondyla kagutsuchi, male and female sexuals are also clonally produced. In contrast to the abovementioned three species, the workers were not only sexually produced but had recombinant sequences in their nuclear internal transcribed spacer regions, although the recombinant sequences were not detected in male or female sexuals. These results suggest that the lineage likely possesses a mechanism to compensate for the reduction in genetic variation due to clonal reproduction with somatic recombination that occurs within the workers.

  3. Androgenesis, gynogenesis and the production of clones in fishes: A review

    NARCIS (Netherlands)

    Komen, J.; Thorgard, G.H.

    2007-01-01

    Fish species that have external fertilization can be reproduced by induced parthenogenesis. The nuclear content of either the sperm or egg is destroyed by UV or gamma irradiation, and the treated gamete then is fused with an untreated egg or sperm to form a haploid embryo. This is subsequently made

  4. Studies on the androgenesis in cultured anthers of Atropa belladonna L.

    Directory of Open Access Journals (Sweden)

    E. Misiura

    2015-01-01

    Full Text Available Embryological investigations were carried out on developing anthers of Atropa belladonna grown in natural conditions and on anthers which produced androgenic embryos in the in vitro culture. The anatomy of developing anthers was analized in details. Meiotic abnormalities were not detected and 36 bivalents were present at metaphase of meiosis I. About 90% of pollen grains were normally developed. Anthers inoculated at the tetrad or microspore stage and cultured on Linsmaier and Skoog medium with kinetin 4 mg/1 and IAA - 2 mg/1 produced androgenic embryos. Differences in the development of septum, in the morphology of pollen grains, formation of tapetum, development of proembryos and the occurrence of storage materials were recorded. The origin of autopoliploid plants from haploid cells is discussed.

  5. Androgenesis in Anther Culture of Lithuanian Spring Barley (Hordeum vulgare L.) and Potato (Solanum tuberosum L.) Cultivars

    OpenAIRE

    ASAKAVICIUTE, Rita

    2008-01-01

    An anther culture method was used for the production of doubled haploids (DHs) in Lithuanian barley and potato cultivars that were directly regenerated from embryoids (Caredda´s method) were applied to determine androgenic potential according to the green regenerant yield and other morphogenetic factors. Green DH regenerants were obtained in 3 Lithuanian spring barley cultivars (´Aidas´, ´Alsa´, and ´Auksiniai´) out of 10 studied. The highest rate of embryoid formation was determined in cv. ...

  6. Quantitative trait loci associated with androgenic responsiveness in triticale (×Triticosecale Wittm.) anther culture.

    Science.gov (United States)

    Krzewska, M; Czyczyło-Mysza, I; Dubas, E; Gołębiowska-Pikania, G; Golemiec, E; Stojałowski, S; Chrupek, M; Zur, I

    2012-11-01

    Quantitative trait loci (QTLs) associated with androgenic responsiveness in triticale were analyzed using a population of 90 DH lines derived from the F1 cross between inbred line 'Saka 3006' and cv. 'Modus', which was used in a number of earlier studies on molecular mapping in this crop. Using Windows QTL Cartographer and MapQTL 5.0, composite interval mapping (CIM) and association studies (Kruskal-Wallis test; K-W) for five androgenesis parameters (androgenic embryo induction, total regeneration and green plant regeneration ability, and two characteristics describing final androgenesis efficiency) were conducted. For the studied components of androgenic response, CIM detected in total 28 QTLs which were localized on 5 chromosomes from A and R genomes. Effects of all QTLs that were identified at 2.0 or above of the LOD score explained 5.1-21.7 % of the phenotypic variation. Androgenesis induction was associated with seven QTLs (LOD between 2.0 and 5.8) detected on chromosomes 5A, 4R, 5R and 7R, all of them confirmed by K-W test as regions containing the markers significantly linked to the studied trait. What is more, K-W test revealed additional markers on chromosomes: 5A, 2BL, 7B and 5R. Both total and green regeneration ability were controlled by genes localized on chromosome 4A. Some of the QTLs that affected final androgenesis efficiency were identical with those associated with androgenic embryo induction efficiency, suggesting that the observed correlation may be either due to tight linkage or to pleiotropy. Key message Five regions of the triticale genome were indicated as revealing significant marker/trait association. Markers located in these regions are potentially useful for triticale breeding through marker-assisted selection.

  7. Adrenocortical function and reserve in children treated for acute lymphoblastic leukemia; Czynnosc i rezerwa korowo-nadnerczowa u dzieci po leczeniu ostrej bialaczki limfoblastycznej

    Energy Technology Data Exchange (ETDEWEB)

    Pawlaczyk, B.; Malecka, E.H.; Krause, W. [Instytut Pediatrii, Akademia Medyczna, Poznan (Poland)

    1993-12-31

    Serum cortisol and 17 OHS, 17 KS and DHA levels in 24-hour urine were determined in 30 children (22 girls and boys) 0.5 to 4 years after completion of therapy (radio- and chemotherapy) for acute lymphoblastic leukemia (ALL). Serum cortisol after Syncthen (adrenocortical reserve) was determined in 15 girls and 4 boys. The results show that therapy for ALL depresses glucocorticosteroid synthesis; however, it does not disturb the adrenal reserve or androgenesis. (author) 15 refs, 6 tabs

  8. [Induction of androgenic cultures in Siberian larch].

    Science.gov (United States)

    Ivanova, A N; Tret'iakova, I N; Viazovetskova, A S

    2006-01-01

    Male generative buds of the Siberian larch have no organic quiescence during the autumn-winter period and are capable of completing the development of male generative structures under favorable conditions. When microsporophylls of the Siberian larch were cultivated on medium MS with 0.2 mg/l 2,4-D, embryoids of two types were obtained: directly from the microspore body and via formation of organogenic callus. This means that in the Siberian larch, direct and indirect androgenesis in vitro is possible. The Siberian larch pollen was first germinated in vitro, which was enhanced by pretreatment with hydrogen peroxide.

  9. [In vitro regeneration and applications using vegetable cell and tissue culture].

    Science.gov (United States)

    Jordán, M

    1990-10-01

    Plant cells by means of their totipotency and aided by in vitro culture techniques can be induced to perform morphogenesis leading to somatic embryoids and massive clonal multiplication; microspores or pollen can be triggered to recover haploid plants, then characters expressed via haploidy can be selected and fixed. Protoplasts from different species can lead to recombinations. We report here work done on Carica pubescens, where somatic embryoids were obtained from cells; in Prunus avium androgenesis leading to pollen calli was triggered, while plants were recovered from Nicotiana tabacum anthers. Fusion products were obtained using C. pubescens and C. papaya protoplasts, leading up to calli and shoots.

  10. Development and application of biological technologies in fish genetic breeding.

    Science.gov (United States)

    Xu, Kang; Duan, Wei; Xiao, Jun; Tao, Min; Zhang, Chun; Liu, Yun; Liu, ShaoJun

    2015-02-01

    Fish genetic breeding is a process that remolds heritable traits to obtain neotype and improved varieties. For the purpose of genetic improvement, researchers can select for desirable genetic traits, integrate a suite of traits from different donors, or alter the innate genetic traits of a species. These improved varieties have, in many cases, facilitated the development of the aquaculture industry by lowering costs and increasing both quality and yield. In this review, we present the pertinent literatures and summarize the biological bases and application of selection breeding technologies (containing traditional selective breeding, molecular marker-assisted breeding, genome-wide selective breeding and breeding by controlling single-sex groups), integration breeding technologies (containing cross breeding, nuclear transplantation, germline stem cells and germ cells transplantation, artificial gynogenesis, artificial androgenesis and polyploid breeding) and modification breeding technologies (represented by transgenic breeding) in fish genetic breeding. Additionally, we discuss the progress our laboratory has made in the field of chromosomal ploidy breeding of fish, including distant hybridization, gynogenesis, and androgenesis. Finally, we systematically summarize the research status and known problems associated with each technology.

  11. BIOTECHNOLOGY OF THE FISH AQUACULTURE

    Directory of Open Access Journals (Sweden)

    L. P. Buchatsky

    2013-12-01

    Full Text Available The latest progress in biotechnology on fish aquaculture and different modern methods of investigations for increasing of fish productivity in aquaculture are analyzed. Except for the applied aspect, the use of modern biotechnological methods of investigations opens new possibilities for fundamental researches of sex-determining mechanisms, polyploidy, distant hybridization, and developmental biology of bony fishes. Review contains examples of utilizing modern biotechnology methods to obtain transgenic fishes with accelerated growth and for designing surrogate fishes. Methods for receiving unisexual shoals of salmon and sturgeon female fishes with the view of obtaining a large quantity of caviar, as well as receiving sterile (triploid fishes are analyzed. Great attention is given to androgenesis, particularly to disperm one, in connection with the problem of conserving rare and vanishing fish species using only sperm genetic material. Examples how distant hybrids may be obtained with the use of disperm androgenesis and alkylated DNA are given. Methods of obtaining fish primordium germ cells, recent developments in cultivation of fish stem cells and their use in biotechnology, as well as ones of transplantation of oogonium and spermatogonium to obtain surrogate fishes. The examples of successful experiments on spermatogonial xenotransplantation and characteristic of antifreezing fish proteins and also the prospect of their practical usage are given.

  12. Reticulate evolution in stick insects: the case of Clonopsis (Insecta Phasmida

    Directory of Open Access Journals (Sweden)

    Milani Liliana

    2010-08-01

    Full Text Available Abstract Background Phasmids show noteworthy abilities to overcome species-specific reproductive isolation mechanisms, including hybridization, polyploidy, parthenogenesis, hybridogenesis and androgenesis. From an evolutionary standpoint, such tangled reproductive interactions lead to the complex phyletic relationships known as "reticulate evolution". Moroccan stick insects of the genus Clonopsis include one bisexual (C. felicitatis and two closely related parthenogenetic forms (C. gallica, C. soumiae, which represent a polyploid series in chromosome number, but with apparent diploid karyotypes. Moreover, two Clonopsis strains of ameiotic males have been described, C. androgenes-35 and C. androgenes-53. As a consequence, Clonopsis stick insects may have experienced complex micro-evolutionary events, which we try to disentangle in this study. Results Mitochondrial cox2 analysis supports a recent divergence of Clonopsis, while AFLPs evidence genetic differentiation not linked to karyotypes, so that parthenogenetic C. gallica and C. soumiae appear to be a mix of strains of polyphyletic origin rather than single parthenogenetic species. Moreover, an admixed hybrid origin seems to be confirmed for C. androgenes. Conclusion On the whole, Clonopsis is an intriguing case of reticulate evolution. Actually, complex cladogenetic events should be taken into account to explain the observed genetic structure, including diploidization of polyploid karyotypes, possibly coupled with hybridization and androgenesis. We also proposed a "working hypothesis" to account for the observed data, which deserves further studies, but fits the observed data very well.

  13. Technical note: Production of tetraploid sturgeons.

    Science.gov (United States)

    Lebeda, I; Flajshans, M

    2015-08-01

    Studies and practical application of androgenesis and gynogenesis in sturgeon are significantly hindered by strong influence of ploidy restoration treatment on survivability of progeny; therefore, developed method of production of tetraploid broodstock and, consequently, use of their diploid gametes might help to avoid ploidy restoration treatment. In the present study, for the first time was developed a protocol for tetraploidy induction in 2 model sturgeon species, sterlet () and Siberian sturgeon (). A high efficiency of treatment was achieved by optimization of heat shock using a temperature of 37°C for 2 min timed between the end of female pronuclei formation and the beginning of pronuclei migration, that is, 0.8 to 1.0 τ (duration of 1 mitotic cycle during the period of synchronous cleavage division). Fertilized eggs developed in tetraploid larvae, up to 31 (89.6% in control) and 34% (70.9% in control) in sterlet and Siberian sturgeon, respectively. Most of the tetraploid larvae exhibited body malformations; as a result, consequent large scale study revealed high larval mortality, which drastically decreased after 2 mo of age. Consequent comparison of BW, length, and malformation rate and mortality between diploid and tetraploid progeny of sterlet did not reveal significant differences in fitness of diploid and tetraploid juveniles at 9 and 11 mo of age. The present study can be considered the first step towards improving the androgenesis methods of conservation of endangered sturgeons as well as understanding the sturgeon sex determination system through induction of mitotic gynogenesis.

  14. Development of embryoids by microspore and anther cultures of red beet (Beta vulgaris L. subsp. vulgaris

    Directory of Open Access Journals (Sweden)

    Krystyna GÓRECKA

    2017-03-01

    Full Text Available So far there is no information about receiving red beet androgenic embryos by androgenesis. Several factors were tested which affected this process: starch accumulation in microspores, correlation between bud length and microsporogenesis course, induction and regeneration medium composition. Ploidy level of obtained regenerants were evaluated. Treating anthers with α-amylase or watering donor plants with gibberellin increased number of obtained androgenic embryos. The highest percentage (80% of microspores at uninuclear stage appeared in buds with 1.3-1.5 mm. The B5 medium with 100 g·L-1 sucrose and 0.1 mg·L-1 2,4-D (2, 4-dichlorophenoxyacetic acid proved to be better for inducing androgenesis than MS medium supplemented with 0.2 mg·L-1 BAP (6-benzylaminopurine and 0.5 mg·L-1 IAA (indole-3-acetic acid. First androgenic embryos were placed on B5 medium without plant growth regulators and then on MS medium containing 0.2 mg·L-1 BAP and 1 mg·L-1 NAA (α-naphthaleneacetic acid. Androgenic embryos died on B5 regeneration medium without plant growth regulators. On MS medium first shoots and callus with and without roots were obtained. Rosettes withered during following passages whereas callus tissue developed further. The quantity of DNA in this tissue equivalent to 4X chromosomes.

  15. Distant hybridization leads to different ploidy fishes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (♀)×common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (♂), and RCC (2n=100) (♀)×blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (♂) are described. In the distant hybridization of RCC (♀)×CC (♂), bisexual fertile F3–F18 allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (♀)×BSB (♂), different ploidy fishes were obtained, including

  16. Distant hybridization leads to different ploidy fishes.

    Science.gov (United States)

    Liu, ShaoJun

    2010-04-01

    Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (female) x common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (male), and RCC (2n=100) (female) x blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (male) are described. In the distant hybridization of RCC (female) x CC (male), bisexual fertile F(3)-F(18) allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (female) x BSB (male), different ploidy fishes were

  17. Artificial induction of androgenetic diploid in Yellow catfish (Pelteobagrus fulvidraco)

    Institute of Scientific and Technical Information of China (English)

    XU Hui; FAN Zhaoting; CHEN Weixing; FANG Jingjie

    2007-01-01

    Androgenesis was the especial zoogamy that the germ plasma of offspring was from the agnate. In this study the eggs of Yellow catfish (Pelteobagrus fulvidraco) were irradiated by UV suspending in the synthetic ovarian fluid (OF), and the total dosage of UV irradiation was 220 mJ·cm-2. Diploid could be induced by heat shock (40℃, 2 min, 3 min) with different time period after fertilization (15-37 min). The result showed that heat shock with 2 min was better than 3 min; there were two apices of induction in 17-21 min and 27-31 min after fertilization. The highest hatching rate was 3.30% at 29 min after fertilization, and the difference between two apices of induction was unobvious.

  18. Exogenous arachidonate restores the dimethoate-induced inhibition of steroidogenesis in rat interstitial cells.

    Science.gov (United States)

    Astiz, Mariana; Hurtado de Catalfo, Graciela; de Alaniz, María J T; Marra, Carlos Alberto

    2012-06-01

    The present work studies the potential restorative effect of polyunsaturated fatty acids (PUFA, 5 μM/24 h) on the dimethoate (DMT)-induced inhibition of testosterone biosynthesis in Leydig cells isolated from rat testes. Various fatty acids (FA) from the n-6 (18:2, 20:3, 20:4, 22:4 and 22:5) and n-3 (18.3, 20:5, 22:5, 22:6) series were assayed in Leydig cells, alone (as delipidated BSA complexes) and in combination with DMT (1 ppm). The n-6 FA stimulated lipid peroxidation (LPO) and inhibited the activities of steroidogenic enzymes (3β- and 17β-hydroxysteroid dehydrogenases). The n-3 FA exerted an anti-oxidant effect, decreasing the production of thiobarbituric-acid reactive substances (TBARS) and inhibiting phospholipase A(2) activity. The biosynthesis of testosterone in DMT-treated cultures was completely normalized by ARA (20:4n-6) and partially restored by the addition of 20:3n-6, increasing ARA content inside the mitochondria. The other FA assayed failed to restore androgenesis. COX-2 protein and prostaglandin F2α and E2 production were stimulated by 20:3n-6, ARA, 18:3n-3 and 20:5 n-3. COX-2 protein decreased upon addition of 22:5n-3 and 22:6n-3. StAR protein was increased by ARA and partially increased by 20:3n-6, likely due to its metabolic conversion into ARA. Both FA increased the mitochondrial cholesterol pool available for testosterone biosynthesis. The rate of androgenesis is likely the result of various regulatory factors acting concomitantly on the physiology of Leydig cells.

  19. 鱼类育种研究进展%The research process of fish genetic breeding

    Institute of Scientific and Technical Information of China (English)

    江丽华; 金媛; 毛勇

    2012-01-01

    本文概括了鱼类的选择育种、驯化及杂交育种等传统鱼类育种方法,叙述了现代生物技术在鱼类育种中的应用,主要有多倍体育种、雌、雄核发育、核移植、转基因育种、分子标记辅助育种、基因组育种;并提出了当今鱼类育种出现的问题。同时,做出了鱼类育种必将走向基因组育种之路的展望,为鱼类育种的发展提供参考。%The paper reported the outlook of fish breeding,the first part was about traditional breeding methods of selective breeding,domestication and cross-breeding,secondly,modern biotechnology in fish breeding was also described,it included polyploidy breeding,androgenesis,nuclear transfer,transgenic,molecular marker assisted breeding and genome breeding.And the challenge and tendency were posed finally.

  20. The mystery of the vanishing Reinke crystals.

    Science.gov (United States)

    Mesa, Hector; Gilles, Scott; Smith, Sophia; Dachel, Susan; Larson, Wendy; Manivel, J Carlos

    2015-04-01

    Reinke crystals (RC) are pathognomonic of Leydig cells (LCs); they are thought to be rare in normal testes and to occur only in approximately one third of LC tumors. We noticed that crystals present in touch imprint and frozen sections of an LC tumor disappeared after tissue fixation. This phenomenon led us to hypothesize that their reported low frequency in normal and neoplastic LCs may be secondary to degradation/dissolution of the crystals after formalin fixation. Our review of the literature also led us to hypothesize that RC are better preserved after air-drying and alcohol fixation. We collected testicular samples from 21 autopsies including air-dried cytologic preparations and tissue samples that were fixed in alcohol or formalin. We found that RC are common in normal LC but dissolve rapidly in formalin and slowly and only partially in alcohol. The composition of RC is unknown; however, they have been reported to stain specifically for nestin, an intermediate filament expressed mainly in neural and muscle tissue. Because the crystals have only been described in androgen-producing cells, we hypothesized that the crystals may represent a crystallized form of androgenic hormones, hormone complexes, or enzymes involved in their synthesis. We performed immunostains for androgens and enzymes involved in androgenesis. We also performed nestin immunostain to confirm the previous study. The crystals stain specifically with antibodies anti-3β-hydroxysteroid dehydrogenase and are negative for the remaining androgenic enzymes, androgenic hormones, and nestin.

  1. Tissue culture-induced genetic and epigenetic variation in triticale (× Triticosecale spp. Wittmack ex A. Camus 1927) regenerants.

    Science.gov (United States)

    Machczyńska, Joanna; Zimny, Janusz; Bednarek, Piotr Tomasz

    2015-10-01

    Plant regeneration via in vitro culture can induce genetic and epigenetic variation; however, the extent of such changes in triticale is not yet understood. In the present study, metAFLP, a variation of methylation-sensitive amplified fragment length polymorphism analysis, was used to investigate tissue culture-induced variation in triticale regenerants derived from four distinct genotypes using androgenesis and somatic embryogenesis. The metAFLP technique enabled identification of both sequence and DNA methylation pattern changes in a single experiment. Moreover, it was possible to quantify subtle effects such as sequence variation, demethylation, and de novo methylation, which affected 19, 5.5, 4.5% of sites, respectively. Comparison of variation in different genotypes and with different in vitro regeneration approaches demonstrated that both the culture technique and genetic background of donor plants affected tissue culture-induced variation. The results showed that the metAFLP approach could be used for quantification of tissue culture-induced variation and provided direct evidence that in vitro plant regeneration could cause genetic and epigenetic variation.

  2. Transmission of the Aegilops ovata chromosomes carrying gametocidal factors in hexaploid triticale (×Triticosecale Wittm.) hybrids.

    Science.gov (United States)

    Kwiatek, M; Majka, M; Ślusarkiewicz-Jarzina, A; Ponitka, A; Pudelska, H; Belter, J; Wiśniewska, H

    2016-08-01

    The main aim of this work was to induce the chromosome rearrangements between Aegilops ovata (UUMM) and hexaploid triticale (AABBRR) by expression of the gametocidal factor located on the chromosome 4M. The Aegilops ovata × Secale cereale (UUMMRR) amphiploids and triticale 'Moreno' were used to produce hybrids by reciprocal crosses. Chromosome dynamics was observed in subsequent generations of hybrids during mitotic metaphase of root meristems and first metaphase of meiosis of pollen mother cells. Chromosomes were identified by genomic in situ hybridisation (GISH) and fluorescence in situ hybridisation (FISH) using pTa71, pTa791, pSc119.2 and pAs1 DNA probes. It has been shown that the origin of the genetic background had an influence on Aegilops chromosome transmission. Moreover, it has been reported that the preferential transmission of chromosome 4M appeared during both androgenesis and gynogenesis. It is also hypothesised that the expression of the triticale Gc gene suppressor had an influence on the semi-fertility of hybrids but did not inhibit the chromosome rearrangements. This paper also describes the double haploid production, which enabled to obtain plants with two identical copies of triticale chromosomes with translocations of Aegilops chromatin segments.

  3. The Chromosomal Constitution of Embryos Arising from Monopronuclear Oocytes in Programmes of Assisted Reproduction

    Directory of Open Access Journals (Sweden)

    Bernd Rosenbusch

    2014-01-01

    Full Text Available The assessment of oocytes showing only one pronucleus during assisted reproduction is associated with uncertainty. A compilation of data on the genetic constitution of different developmental stages shows that affected oocytes are able to develop into haploid, diploid, and mosaic embryos with more or less complex chromosomal compositions. In the majority of cases (~80%, haploidy appears to be caused by gynogenesis, whereas parthenogenesis or androgenesis is less common. Most of the diploid embryos result from a fertilization event involving asynchronous formation of the two pronuclei or pronuclear fusion at a very early stage. Uniparental diploidy may sometimes occur if one pronucleus fails to develop and the other pronucleus already contains a diploid genome or alternatively a haploid genome undergoes endoreduplication. In general, the chance of obtaining a biparental diploid embryo appears higher after conventional in vitro fertilization than after intracytoplasmic sperm injection. If a transfer of embryos obtained from monopronuclear oocytes is envisaged, it should be tried to culture them up to the blastocyst since most haploid embryos are not able to reach this stage. Comprehensive counselling of patients on potential risks is advisable before transfer and a preimplantation genetic diagnosis could be offered if available.

  4. A milestone in the doubled haploid pathway of cassava: a milestone in the doubled haploid pathway of cassava (Manihot esculenta Crantz): cellular and molecular assessment of anther-derived structures.

    Science.gov (United States)

    Perera, P I P; Ordoñez, C A; Lopez-Lavalle, L A Becerra; Dedicova, B

    2014-01-01

    This study was aimed at inducing androgenesis in cultured anthers of cassava (Manihot esculenta Crantz) to develop a protocol for the production of doubled haploids. Microspore reprogramming was induced in cassava by cold or heat stress of anthers. Since the anthers contain both haploid microspores and diploid somatic cells, it was essential to verify the origin of anther-derived calli. The origin of anther-derived calli was assessed by morphological screening followed by histological analysis and flow cytometry (FCM). Additionally, simple sequence repeat (SSR) and amplified fragmented length polymorphism (AFLP) assays were used for the molecular identification of the microspore-derived calli. The study clearly demonstrated the feasibility of producing microspore-derived calli using heat- or cold-pretreated anthers. Histological studies revealed reprogramming of the developmental pathway of microspores by symmetrical division of the nucleus. Flow cytometry analysis revealed different ploidy level cell types including haploids, which confirmed their origin from the microspores. The SSR and AFLP marker assays independently confirmed the histological and FCM results of a haploid origin of the calli at the DNA level. The presence of multicellular microspores in the in vitro system indicated a switch of developmental program, which constitutes a crucial step in the design of protocols for the regeneration of microspore-derived embryos and plants. This is the first detailed report of calli, embryos, and abnormal shoots originated from the haploid cells in cassava, leading to the development of a protocol for the production of doubled haploid plants in cassava.

  5. Effect of a PCB-based transformer oil on testicular steroidogenesis and xenobiotic-metabolizing enzymes.

    Science.gov (United States)

    Andric, Nebojsa L; Kostic, Tatjana S; Zoric, Sonja N; Stanic, Bojana D; Andric, Silvana A; Kovacevic, Radmila Z

    2006-07-01

    Pyralene is a PCB-based transformer oil with a unique PCB congener profile when compared to other mixtures. We studied the influence of Pyralene on testicular steroidogenesis and the status of xenobiotic-metabolizing enzymes in the testis and liver of rats during oral exposure (10 and 50 mg/kg body weight, p.o. daily for 1 week) and a 3-week post-treatment recovery period. As expected, Pyralene induced a rapid and sustained increase in mRNA transcripts for CYP1A1 and CYP2B1 in hepatocytes that was associated with a dramatic increase in ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-deethylase (PROD) activities. Testicular androgenesis and the conversion of progesterone to testosterone in testicular microsomes were bidirectionally affected. An increase in these parameters was observed 24h after the initial administration of Pyralene, followed by inhibition that lasted until the fourth post-treatment day. Expression PCR analysis revealed a significant decrease in 17beta-hydroxysteroid dehydrogenase (17betaHSD) transcript abundance at 48 h after Pyralene administration. In contrast, transcripts for several other steroidogenic enzymes and for testicular CYP1A1, CYP1B1, and CYP2B1 were unaffected under the same conditions. These results in the rat indicate that a sub-chronic exposure to Pyralene disrupted testicular steroidogenesis and suggest the mechanism may involve direct action on the regulation of specific steroidogenic enzymes such as 17betaHSD.

  6. Ethanol induces mouse spermatogenic cell apoptosis in vivo through over-expression of Fas/Fas-L, p53, and caspase-3 along with cytochrome c translocation and glutathione depletion.

    Science.gov (United States)

    Jana, Kuladip; Jana, Narayan; De, Dipak Kumar; Guha, Sujoy Kumar

    2010-09-01

    Although it has been well established that spermatogenic cells undergo apoptosis when treated with ethanol, the molecular mechanisms behind it remain to be investigated. Adult male mice were given intra-peritoneal injection (IP) of ethanol at a dose of 3 g (15%, v/v) per kg body weight per day during the period of 14 days. Testicular androgenesis and apoptotic germ cell death, along with different interrelated proteins expression, were evaluated. Ethanol treatment induced apoptotic spermatogenic cell death with a decrease in the plasma and intra-testicular testosterone concentration. Western blot analysis revealed that repeated ethanol treatment decreased the expression of steroidogenic acute regulatory protein (StAR), 3 beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17 beta-hydroxysteroid dehydrogenase (17beta-HSD); increased the expression of active caspase-3, p53, Fas and Fas-L; and led to up-regulation of Bax/Bcl-2 ratio and translocation of cytochrome c from mitochondria to cytosol in testis. It has also been shown in our study that repeated ethanol treatment led to up-regulation of caspase-3, p53, Fas, Fas-L transcripts; increase in caspase-3 and caspase-8 activities; diminution of 3beta-HSD, 17beta-HSD, and GPx activities; decrease in the mitochondrial membrane potential along with ROS generation and depletion of glutathione pool in the testicular tissue. The present study has indicated that the ethanol treatment induced apoptosis in the mouse testis through the increased expression of Fas/Fas-L and p53, up-regulation of Bax/Bcl-2 ratio, cytosolic translocation of cytochrome c along with caspase-3 activation and glutathione depletion.

  7. Improving the efficiency of isolated microspore culture in six-row spring barley: I-optimization of key physical factors.

    Science.gov (United States)

    Esteves, Patricio; Belzile, François

    2014-06-01

    An improved isolated microspore culture protocol alleviating the recalcitrance typically observed in six-row spring barley was developed by optimizing four key physical factors to increase embryogenesis and reduce albinism. Doubled haploid (DH) plants are completely homozygous individuals that can be generated in just a few months via androgenesis in vitro. DHs are useful tools in genetic research and in plant breeding. Isolated microspore culture (IMC) is the most efficient way to produce DHs, but a strong genotype dependency imposes limitations to its wide application. Six-row, spring barley genotypes are considered as particularly recalcitrant due to a low frequency of embryogenesis and a high rate of albinism. Seeking to develop an efficient IMC protocol for this type of barley, we explored four important factors: (1) the harvest stage of immature spikes, (2) the type of pretreatment applied, (3) the osmotic potential in the induction medium, and (4) the plating density of microspores. This work was first performed using four barley genotypes: two typical six-row spring cultivars (ACCA and Léger), a two-row spring (Gobernadora) and a two-row winter (Igri) cultivar. First, by optimizing the harvest stage for each genotype we obtained a twofold to fourfold increase in the yield of embryogenic microspores. Second, two pretreatments (0.3 M mannitol for 2 days, or a combination of cold and heat over 15 days) both performed significantly better than the commonly used cold pretreatment (28 days at 4 °C). Third, an induction medium-containing mannitol (32 g/l) doubled green plant regeneration. Fourth, a plating density of 10(6) microspores/ml yielded the highest number of green regenerated plants. Our most important findings were then confirmed using sets of F1s from a six-row, spring-type breeding program.

  8. Reprogramming of cassava (Manihot esculenta) microspores towards sporophytic development.

    Science.gov (United States)

    Perera, P I P; Ordoñez, C A; Dedicova, B; Ortega, P E M

    2014-05-21

    Gametes have the unique potential to enter the sporophytic pathway, called androgenesis. The plants produced are usually haploid and recombinant due to the preceding meiosis and they can double their chromosome number to form doubled haploids, which are completely homozygous. Availability of the doubled haploids facilitates mapping the genes of agronomically important traits, shortening the time of the breeding process required to produce new hybrids and homozygous varieties, and saving the time and cost for inbreeding. This study aimed to test the feasibility of using isolated and in vitro cultured immature cassava (Manihot esculenta) microspores to reprogramme and initiate sporophytic development. Different culture media and different concentrations of two ion components (Cu(2+) and Fe(2+)) were tested in two genotypes of cassava. External structural changes, nuclear divisions and cellular changes during reprogramming were analysed by scanning electron microscopy, by staining with 4',6-diamidino-2-phenylindole, and through classical histology and transmission electron microscopy. In two cassava genotypes, different developmental stages of microspores were found to initiate sporophytic cell divisions, that is, with tetrads of TMS 60444 and with mid or late uni-nucleate microspores of SM 1219-9. In the modified NLN medium (NLNS), microspore enlargements were observed. The medium supplemented with either sodium ferrous ethylene-diamine-tetraacetic acid (NaFeEDTA) or CuSO4·5H2O induced sporophytic cell division in both genotypes. A low frequency of the reprogramming and the presence of non-responsive microspores among the responsive ones in tetrads were found to be related to the viability and exine formation of the microspores. The present study clearly demonstrated that reprogramming occurs much faster in isolated microspore culture than in anther culture. This paves the way for the development of an efficient technique for the production of homozygous lines in

  9. ROLE OF POLYAMINES IN INHIBITION OF ETHYLENE BIOSYNTHESIS AND THEIR EFFECTS ON RICE ANTHER CULTURE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Iswari S. Dewi

    2016-10-01

    Full Text Available The polyamines such as putrescine, spermidine, and spermine were reported to increase green plant regeneration in rice anther culture. Low response of anther culture of rice sub-species indica may be improved with the addition of putrescine in the culture media. Four experiments were conducted to study the role of polyamines in inhibition of ethylene biosynthesis and their effects on rice anther culture development. Anthers of two subspecies of rice, indica (IR64, Krowal, Jatiluhur and japonica (Taipei 309 were cultured onto media supplemented with putrescine (N6P and without putrescine (N6. Youngpanicles containing the anthers at mid-to-late nucleate microspores were cold pretreated at 5 + 2°C and incubated in the dark for 8 days before the anthers were cultured. Resultsshowed that medium without putrescine produced an earlier senescence of indica rice anther than that of japonica. The addition of 10-3 M putrescine into the culture media inhibited ethylene biosynthesis as anther senescence delayed, increased the three polyamines contents, and decreased the ACC content as well as ACC oxydase activity in anther-derived calli. In the anther and anther-derived calli of subspecies indica, the totalpolyamines content was lower (10.14 nM g-1 anther and 8.48 nM g-1 calli than that of subspecies japonica (12.61 nM g-1 anther and 10.16 nM g-1 calli, whereas the ethylene production was higher (32.31 nM g-1 anther and 2.48 nM g-1 calli than the japonica (31.68 nM g-1 anther and 1.76 nM g-1 calli. This study suggests that application of 10-3 M putrescine in anther culture of rice subspecies indica improves androgenesis by inhibitingearly senescence of cultured anthers and enhancing embryo or callus formation from microspores.

  10. Development and use of genetically uniform strains of common carp in experimental animal research.

    Science.gov (United States)

    Bongers, A B; Sukkel, M; Gort, G; Komen, J; Richter, C J

    1998-10-01

    Fish are widely used in numerous fields of basic and applied research. Currently, they are the third laboratory animal group in numbers, and will become increasingly important. Common carp is a major species in both aquaculture and research. Inbred strains of carp by gynogenetic (only female inheritance) and androgenetic (only male inheritance) reproduction techniques were developed at our university. With these methods, homozygous animals are produced in one generation and we present the production of homozygous inbred and F1 hybrid strains of common carp. As in mammalian research, using genetically well defined fish is a methodological necessity since in outbred stocks: (1) repeatability between experiments is low, (2) high levels of inbreeding may have accumulated and (3) high intrastrain variability might obscure treatment effects. Within inbred strains, the variation is reduced and as a result, less animals (compared to outbreds) are necessary to obtain statistically significant results. We illustrate this with experimental data from an F1 hybrid and partly outbred strain of common carp, both subjected to an antibiotic treatment resulting in reduced gonadal growth. Results obtained from a single inbred strain should be generalized with the use of a panel of inbred strains. We show that optimal allocation of animals between and within inbred strains depends on the ratio (variation between strains): (variation within strains). When selecting a panel of inbred strains, attention has to be paid to genetic relations between strains to avoid testing within a limited genetic range. It should be considered that in inbred strains, (genic) dominance and interaction effects are absent, due to the absence of heterozygous genotypes. In general, variation within inbred strains will be reduced for traits with a high degree of genetic determination. However, in inbred strains of carp produced by gynogenesis or androgenesis, the chromosome manipulation treatment induces

  11. Haplodiploid androgenetic breeding in oat: genotypic variation in anther size and microspore development stage Melhoramento por haplodiploidização androgenética: variação genotípica no tamanho das anteras e no estágio de desenvolvimento dos micrósporos em aveia

    Directory of Open Access Journals (Sweden)

    Taniela De Cesaro

    2009-02-01

    Full Text Available Oat (Avena spp. is poorly responsive to the haplodiploidization process, which leads to the production of homozygous lines in one step, increasing breeding efficiency. Androgenetic haploids in small grain cereal crops are obtained from microspores cultured at the mononucleate stage, which can be identified by the size of anthers. In order to identify the appropriate anther size for in vitro culture, microspore cytological analyses were made in Avena sativa cultivars UPF 7, UPF 18, UFRGS 14, Stout and Avena sterilis CAV 3361, cultivated in growth chamber under controlled light and temperature conditions. Variation was observed within and among genotypes for anther size at each microspore developmental stage and according to the position of spikelets in the panicle. Architecture variation in panicle shape and non-linear microsporogenesis maturation increased the challenge of identifying potentially androgenetic oat anthers. Cytological screening before culture is critical in identifying microspores at the right stage for oat androgenesis.A aveia (Avena spp. tem sido pouco responsiva à haplodiploidização, um processo que aumenta a eficiência da seleção no melhoramento por gerar, em uma etapa, linhas puras homozigóticas. A fase mononucleada do micrósporo é critica para o sucesso da androgênese in vitro nos cereais de inverno e, em geral, pode ser inferida pelo tamanho da antera. Foram medidas anteras e analisados citológicamente micrósporos das cultivares de Avena sativa UPF 7, UPF 18, UFRGS 14, Stout e da linhagem CAV 3361 de Avena sterilis, cultivadas em câmaras de crescimento sob temperaturas dia-noite variando de 16ºC a 9ºC e 12 horas de intensidade luminosa de 300 mol m-2 s-1. O tamanho das anteras em cada fase de desenvolvimento dos micrósporos variou significativamente entre genótipos e de acordo com a região de inserção das espiguetas na panícula. A variação na arquitetura da panícula e a maturação não linear das

  12. 小麦×玉米远缘杂交技术以及在单倍体育种上的应用评价%The Distant Hybridization Technology of Wheat×Maize System and Application Evaluation of Haploid Breeding

    Institute of Scientific and Technical Information of China (English)

    陈淑萍; 王雪征; 唐怀君; 茜晓哲

    2011-01-01

    为了提高小麦作物育种选择的精确性和效率,应用小麦亲本杂交后代F1(或F2)代与玉米进行远缘杂交,经激素诱导和组织培养形成单倍体胚及植株,加倍单倍体(DH)育种结合分子标记和性状表达,达到了单代纯化培育小麦新品系的生产能力;本文阐述了小麦×玉米远缘杂交发展进程,分析了小麦×玉米远缘杂交较孤雄生殖、球茎大麦技术等具备的优势特点,探讨了提高单倍体胚、单倍体植株产生频率以及染色体加倍效率的途径,展望了小麦×玉米杂交组合对于未来高效改进小麦育种程序具有的巨大潜力和发展前景.%In order to in crease the precision and efficacy of selection process in crop breeding, the distant hybridization between wheat filial generation of F, (or F2) and Maize intergeneric crosses is applied, after auxin 2,4-D induction and tissue culture, polyhaploid embryo and plant have developed, The use of dihaploid (DH) technology combining with molecular marker-assisted selection (MAS) and trait expression greatly enhances the production of complete homozygous wheat lines in a single generation; In this paper, we try to elucidate the methods available for haploid production, reveal the superiority of wheatxmaize system of crosses over Androgenesis and Bulbosum techniques, research the strategic on enhancement of embryo formation, green polyhaploid plant regeneration and doubled haploid, look ahead the potentiality and the prospect of wheatxmaize system of crosses for improving the efficiency of future wheat breeding program.

  13. Morphological markers for microspore developmental stage in maize

    Directory of Open Access Journals (Sweden)

    Ana Paula de Moraes

    2008-10-01

    Full Text Available The use of maize in anther culture has been limited because only few genotypes presented a high androgenetic potential. Obtaining the proper stage of microspore development at culture initiation is one of the most crucial factors for success in the androgenesis. For Brazilian maize genotypes there are no studies reporting a correlation between cytological features and morphological parameters. In this study, morphological parameters were recorded and associated with cytological specific stages of the the microsporogenesis in two Brazilian maize genotypes that were sowed in different places (field and growing chamber. For both genotypes, the plants of the growing chamber presented a delay in development. Spikelets length and anther length/spikelet length ratio are not good parameters since they can be greatly influenced by the environment. The anther length was the more reliable parameter to correlate with a specific developmental stage. Nevertheless, variations between genotypes and environment were detected.A utilização do milho (Zea mays na cultura de anteras é limitada devido ao baixo número de genótipos com alto potencial androgenético. A obtenção de micrósporos no estádio de desenvolvimento apropriado no início da cultura é um dos fatores cruciais para o sucesso do processo androgenético. Em genótipos brasileiros de milho não existem estudos relatando a correlação entre características citológicas e parâmetros morfológicos. Neste estudo, parâmetros morfológicos foram avaliados e associados com estádios específicos da microsporogênese em dois genótipos brasileiros de milho os quais foram semeados em diferentes locais (campo e câmara de crescimento. Para ambos os genótipos, as plantas crescidas na câmara de crescimento apresentaram atraso no desenvolvimento. O comprimento da espigueta e a razão comprimento da antera/comprimento da espigueta não são bons parâmetros uma vez que podem ser muito influenciados

  14. Quantification of the tissue-culture induced variation in barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Bednarek Piotr T

    2007-03-01

    Full Text Available Abstract Background When plant tissue is passaged through in vitro culture, many regenerated plants appear to be no longer clonal copies of their donor genotype. Among the factors that affect this so-called tissue culture induced variation are explant genotype, explant tissue origin, medium composition, and the length of time in culture. Variation is understood to be generated via a combination of genetic and/or epigenetic changes. A lack of any phenotypic variation between regenerants does not necessarily imply a concomitant lack of genetic (or epigenetic change, and it is therefore of interest to assay the outcomes of tissue culture at the genotypic level. Results A variant of methylation sensitive AFLP, based on the isoschizomeric combinations Acc65I/MseI and KpnI/MseI was applied to analyze, at both the sequence and methylation levels, the outcomes of regeneration from tissue culture in barley. Both sequence mutation and alteration in methylation pattern were detected. Two sets of regenerants from each of five DH donor lines were compared. One set was derived via androgenesis, and the other via somatic embryogenesis, developed from immature embryos. These comparisons delivered a quantitative assessment of the various types of somaclonal variation induced. The average level of variation was 6%, of which almost 1.7% could be accounted for by nucleotide mutation, and the remainder by changes in methylation state. The nucleotide mutation rates and the rate of epimutations were substantially similar between the andro- and embryo-derived sets of regenerants across all the donors. Conclusion We have developed an AFLP based approach that is capable of describing the qualitative and quantitative characteristics of the tissue culture-induced variation. We believe that this approach will find particular value in the study of patterns of inheritance of somaclonal variation, since non-heritable variation is of little interest for the improvement of plant

  15. [Phenomenon of polyembryony. Genetic heterogeneity of seeds].

    Science.gov (United States)

    Batygina, T B; Vinogradova, G Iu

    2007-01-01

    Different concepts of polyembryony and genetic heterogeneity of seeds in flower plants have been reviewed. Different types, ways, and forms of plant reproduction appeared in the course of evolution as a consequences of the attached mode of life and autotrophy. This is ascribed to totipotency, "stemminess" of plant cells, and presence of constantly functioning meristems, which determined to a great extent the system of plant safety. There are two ways of formation of a new individual: sexual process --> gamospermy involving meiosis and gamete fusion and asexual process --> agamospermy without meiosis and gamete fusion and two types of reproduction: seed and vegetative. Both processes may take place simultaneously in one seed, as a result of which many embryos of different origins are formed: uniparental and biparental inheritance. Traditionally, this phenomenon is called polyembryony. It comprises embryoidogeny (a new category of vegetative reproduction): formation of somatic embryos (= embryoids) in the flower, seed, and on vegetative organs. Genetic heterogeneity is one of the most important characteristics of seeds, which is based on different phenomena, such as embryogeny, embryoidogeny, and gametophytic and sporophytic apomixes. When describing two types of polyembryony, sporophytic (nucellar, integumental, cleavage) and gametophytic (synergidal, antipodal), a great attention is paid to characterization of initial cells of the sexual and adventive embryos. A new concept of apogamety is developed from new positions (totipotency and "stemminess"), which is based on different genesis of cells of the egg and antipodal systems. Five possible pathways of formation of the adventive embryos have been proposed from cells of the egg apparatus. Specific features of the formation of adventive embryos in the case of gametophytic apomixis, such as androgenesis and semigamy, are discussed. Morphogenesis of the sexual and adventive embryos proceeds in the mother organism and

  16. Genetic studies on sex determination and colouration in Nile tilapia (Oreochromis niloticus L.)

    Energy Technology Data Exchange (ETDEWEB)

    Karayuecel, I

    1999-05-01

    The present study was undertaken to investigate colour and sex determination mechanisms through the application of androgenesis, gynogenesis and controlled breeding programme with the objective of producing all red males in O. niloticus. The highest yield of androgenetic haploid to pigmentation stage was 24.6{+-}3.5% (relative to controls) with optimal UV irradiation dose of 450JM{sup -2} for 5 minutes. The highest survival rate of diploid androgens was 0.07{+-}0.07% (relative to controls) to yolk sac stage using a heat shock of 42.5 deg. C for 3 minutes 30 seconds applied at 25 minutes after fertilisation. All paternal inheritance of diploid androgenetic tilapia was verified using DNA fingerprinting. The mean recombination frequency of the red skin colour gene in meiotic gynogens was 0.12{+-}0.04. All maternal inheritance of meiotic gynogens was verified using the isozyme locus ADA*. Analyses of sex ratios of meiotic gynogens suggested that male progenies were produced by an epistatic sex determining locus (SDL-2 with two alleles SR and sr) causing female to male sex reversal in the homozygous phase (srsr) but with limited penetrance. A close linkage was found between a sex determining locus (SDL-2) and the red gene. No significant difference was found between colour genotypes (namely homozygous red, heterozygous red and wild type) in terms of total fecundity, ISI (inter spawning interval), egg size and survival rate. Overall mean ISI was 26.3{+-}1.0 days. Mean total fecundity was 1096 eggs. Fecundity varied over successive spawns but this variation did not appear to be related to spawning periodicity. Hormonal and thermal feminization were compared on all YY male progeny of O. niloticus. While similar female percentages of 32.0{+-}5.2 and 33.8{+-}1.5% were produced, significantly higher intersex percentages of 18.5{+-}2.5 and 1.6{+-}0.8 were observed in heat and DES treated groups, respectively. Heat treatment groups showed the lowest survival rate of 62

  17. Associação de fases meióticas e estádios dos micrósporos com características morfológicas de botões florais de pimentão Association of meiotic phases and microspore stages with morphological characters of floral buds of pepper

    Directory of Open Access Journals (Sweden)

    Edgard Augusto de Toledo Picoli

    2003-06-01

    Full Text Available Fases meióticas e estádios de micrósporos de pimentão (Capsicum annuum L. cv. Azeth foram determinados e associados com características morfológicas adotadas para a seleção de botões florais a serem utilizados na indução de androgênese. Plantas foram mantidas em casa-de-vegetação para coleta dos botões florais, que foram separados em seis classes de acordo com a relação de tamanho entre cálice e corola e presença de pigmentos nas anteras. As anteras foram fixadas em metanol: ácido acético na proporção de 3:1 e armazenadas a -20º C. Preparações citogenéticas desse material foram montadas pela técnica de dissociação e secagem ao ar e coradas com solução de Giemsa. As observações dos botões foram realizadas sob lupa e as preparações citogenéticas em microscópio ótico. Imagens dos botões florais, das anteras e das fases meióticas foram digitalizadas em computador para documentação. Variações de fases meióticas dentro de cada classe de botão floral foram observadas. Embora o critério de presença de antocianina na extremidade das anteras tenha sido aplicado para outras variedades, o mesmo não se mostrou adequado para a determinação do estádio de micrósporo neste estudo. As fases meióticas foram citogeneticamente identificadas; contudo, não foi possível estabelecer sua associação com as classes dos botões florais. Entretanto, botões com o tamanho de cálice coincidindo com o da corola apresentaram maior número de micrósporos em estádio adequado para a cultura de anteras.In the present study, morphological characters adopted for floral bud selection used for androgenesis induction were associated with pepper (Capsicum annuum L. cv. Azeth meiotic phases and microspore stages. Floral buds were harvested from greenhouse-grown plants and separated into six classes according to size relationships between calyx and corolla, and anthocyanin pigmentation in anthers. After sorting by size, buds

  18. Effects of chronic exposure to sodium arsenite on hypothalamo-pituitary-testicular activities in adult rats: possible an estrogenic mode of action

    Directory of Open Access Journals (Sweden)

    Jana Subarna

    2006-02-01

    Full Text Available Abstract Background Inorganic arsenic is a major water pollutant and a known human carcinogen that has a suppressive influence on spermatogenesis and androgenesis in male reproductive system. However, the actual molecular events resulting in male reproductive dysfunctions from exposure to arsenic remain unclear. In this context, we evaluated the mode of action of chronic oral exposure of sodium arsenite on hypothalamo-pituitary- testicular activities in mature male albino rats. Methods The effect of chronic oral exposure to sodium arsenite (5 mg/kg body weight/day via drinking water without or with hCG (5 I.U./kg body weight/day and oestradiol (25 micrograms oestradiol 3-benzoate suspended in 0.25 ml olive oil/rat/day co-treatments for 6 days a week for 4 weeks (about the duration of two spermatogenic cycle was evaluated in adult male rats. Changes in paired testicular weights, quantitative study of different varieties of germ cells at stage VII of spermatogenic cycle, epididymal sperm count, circulatory concentrations of hormones (LH, FSH, testosterone and corticosterone, testicular activities of delta 5, 3beta-hydroxysteroid dehydrogenase (delta 5, 3beta-HSD, 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD, sorbitol dehydrogenase (SDH, acid phosphatase (ACP, alkaline phosphatase (ALP, and lactate dehydrogenase (LDH, as well as the levels of biogenic amines (dopamine, noradrenaline and 5-hydroxytryptamine (5-HT in the hypothalamus and pituitary were monitored in this study. Hormones were assayed by radioimmuno- assay or enzyme- linked immunosorbent assay and the enzymes were estimated after spectrophotometry as well as the biogenic amines by HPLC electrochemistry. Results Sodium arsenite treatment resulted in: decreased paired testicular weights; epididymal sperm count; plasma LH, FSH, testosterone and testicular testosterone concentrations; and increased plasma concentration of corticosterone. Testicular enzymes such as delta 5, 3 beta

  19. Calogênese in vitro em anteras de coffea arabica L. In vitro callogenesis in anthers of Coffea arabica L.

    Directory of Open Access Journals (Sweden)

    Ednamar Gabriela Palú

    2004-08-01

    Full Text Available O café é um dos mais importantes produtos do mercado internacional; porém, o tempo gasto e os recursos despendidos são fatores limitantes para o melhoramento do cafeeiro por meio de métodos convencionais. Contudo, a cultura de anteras surge como uma alternativa viável e de curto prazo para solução desses problemas. Com o presente trabalho, objetivou-se a produção de dihaplóides com a cultura de anteras do cafeeiro (androgênese indireta, buscando um protocolo para a fase de indução de calos. Para tanto, foi efetuada a assepsia dos botões florais e das anteras, que, em seguida, foram inoculadas em meio IC e mantidas no escuro por 8 semanas, sob temperatura de 25ºC ± 1. Para induzir a calogênese em anteras da cv. Acaiá Cerrado, foram testadas as concentrações de 2,4-D (0, 1, 2 e 4 mg.L-1 x cinetina (0, 2, 4 e 8 mg.L-1 e 2,4-D (0; 0,5; 1 e 2 mg.L-1 x AIB (0; 0,5; 1 e 2 mg.L-1 mais 2iP (2 mg.L-1 e, para a cv. Rubi, as concentrações de 2,4-D (0, 1, 2 e 4 mg.L-1 x cinetina (0, 2, 4 e 8 mg.L-1. Foi observado que a maior porcentagem de indução de calogênese em anteras na cv. Acaiá Cerrado ocorre com as combinações de 2,4-D (2 mg.L-1 + cinetina (1,9 mg.L-1 e 2,4-D (0,86 mg.L-1 + AIB (1 mg.L-1+ 2iP (2 mg.L-1; para cv. Rubi, a combinação de 2,4-D (1,9 mg.L-1 e cinetina (4 mg.L-1.The coffee is one of the most important products of the international market, however the time and money wasted in breeding programs are limiting factors for its improvement. However, the anther culture appears as a viable alternative for a short time period solution for this problem. This work aimed to obtain the double haploids production from anther cultures of the coffee plant (indirect androgenesis aiming to optimize a protocol calluse induction. For this purpose, asseptic conditions of the flower budsand anthers were accomplished, folowed by inoculationin IC medium and the tissue were kept for eight weeks at 25ºC ± 1 in the dark. To induce