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Sample records for lazy-2 gravitropic mutant

  1. High-resolution mapping and genetic characterization of the Lazy-2 gravitropic mutant of tomato

    Science.gov (United States)

    Behringer, F. J.; Lomax, T. L.

    1999-01-01

    Mutation of the Lazy-2 (Lz-2) gene in tomato (Lycopersicon esculentum mill.) produces a phytochrome-dependent reversal of shoot gravitropism, providing a unique genetic resource for investigating how signals from light modulate gravitropism. We mapped the Lz-2 gene using RFLPs and a PCR-based technique to assess the feasibility of positional cloning. Analysis of a 1338 plant backcross population between L. esculentum and L. pennellii placed Lz-2 within a 1.2 cM interval on chromosome 5, 0.4 cM from TG504-CT201A interval. The inabililty to resolve these markers indicates that Lz-2 resides in a centromeric region in which recombination is highly suppressed. Lazy-2 is tightly linked to but does not encode the gene for ACC4, an enzyme involved in ethylene biosynthesis. We also observed that Lz-2 is partially dominant under certain conditions and stages of development.

  2. Isolation of new gravitropic mutants under hypergravity conditions

    Directory of Open Access Journals (Sweden)

    Akiko Mori

    2016-09-01

    Full Text Available Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upwards. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes. In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using Next-Generation Sequencing (NGS and Single Nucleotide Polymorphism (SNP-based markers. Using the endodermal-amyloplast less 1 (eal1 mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene (enhancer of eal1 mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis.

  3. Isolation of New Gravitropic Mutants under Hypergravity Conditions.

    Science.gov (United States)

    Mori, Akiko; Toyota, Masatsugu; Shimada, Masayoshi; Mekata, Mika; Kurata, Tetsuya; Tasaka, Masao; Morita, Miyo T

    2016-01-01

    Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upward. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using next-generation sequencing (NGS) and single nucleotide polymorphism (SNP)-based markers. Using the endodermal-amyloplast less 1 ( eal1 ) mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g) restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene ( enhancer of eal1 ) mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis .

  4. Isolation of new gravitropic mutants under hypergravity conditions

    OpenAIRE

    Akiko Mori; Masatsugu Toyota; Masatsugu Toyota; Masayoshi Shimada; Mika Mekata; Tetsuya Kurata; Masao Tasaka; Miyo Terao Morita

    2016-01-01

    Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upwards. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we ...

  5. Isolation of New Gravitropic Mutants under Hypergravity Conditions

    OpenAIRE

    Mori, Akiko; Toyota, Masatsugu; Shimada, Masayoshi; Mekata, Mika; Kurata, Tetsuya; Tasaka, Masao; Morita, Miyo T.

    2016-01-01

    Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upward. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we r...

  6. Identification of a Gravitropism-Deficient Mutant in Rice

    Directory of Open Access Journals (Sweden)

    He Yan

    2017-03-01

    Full Text Available A gravitropism-deficient mutant M96 was isolated from a mutant bank, generated by ethyl methane sulfonate (EMS mutagenesis of indica rice accession ZJ100. The mutant was characterized as prostrate growth at the beginning of germination, and the prostrate growth phenotype ran through the whole life duration. Tiller angle and tiller number of M96 increased significantly in comparison with the wild type. Tissue section observation analysis indicated that asymmetric stem growth around the second node occurred in M96. Genetic analysis and gene mapping showed that M96 was controlled by a single recessive nuclear gene, tentatively termed as gravitropism-deficient M96 (gdM96, which was mapped to a region of 506 kb flanked by markers RM5960 and InDel8 on the long arm of chromosome 11. Sequencing analysis of the open reading frames in this region revealed a nucleotide substitution from G to T in the third exon of LOC_Os11g29840. Additionally, real-time fluorescence quantitative PCR analysis showed that the expression level of LOC_Os11g29840 in the stems was much higher than in the roots and leaves in M96. Furthermore, the expression level was more than four times in M96 stem than in the wild type stem. Our results suggested that the mutant gene was likely a new allele to the reported gene LAZY1. Isolation of this new allele would facilitate the further characterization of LAZY1.

  7. The cytoskeleton and gravitropism in higher plants

    Science.gov (United States)

    Blancaflor, Elison B.

    2002-01-01

    The cellular and molecular mechanisms underlying the gravitropic response of plants have continued to elude plant biologists despite more than a century of research. Lately there has been increased attention on the role of the cytoskeleton in plant gravitropism, but several controversies and major gaps in our understanding of cytoskeletal involvement in gravitropism remain. A major question in the study of plant gravitropism is how the cytoskeleton mediates early sensing and signal transduction events in plants. Much has been made of the actin cytoskeleton as the cellular structure that sedimenting amyloplasts impinge upon to trigger the downstream signaling events leading to the bending response. There is also strong molecular and biochemical evidence that the transport of auxin, an important player in gravitropism, is regulated by actin. Organizational changes in microtubules during the growth response phase of gravitropism have also been well documented, but the significance of such reorientations in controlling differential cellular growth is unclear. Studies employing pharmacological approaches to dissect cytoskeletal involvement in gravitropism have led to conflicting results and therefore need to be interpreted with caution. Despite the current controversies, the revolutionary advances in molecular, biochemical, and cell biological techniques have opened up several possibilities for further research into this difficult area. The myriad proteins associated with the plant cytoskeleton that are being rapidly characterized provide a rich assortment of candidate regulators that could be targets of the gravity signal transduction chain. Cytoskeletal and ion imaging in real time combined with mutant analysis promises to provide a fresh start into this controversial area of research.

  8. Regulation of auxin transport during gravitropism

    Science.gov (United States)

    Rashotte, A.; Brady, S.; Kirpalani, N.; Buer, C.; Muday, G.

    Plants respond to changes in the gravity vector by differential growth across the gravity-stimulated organ. The plant hormone auxin, which is normally basipetally transported, changes in direction and auxin redistribution has been suggested to drive this differential growth or gravitropism. The mechanisms by which auxin transport directionality changes in response to a change in gravity vector are largely unknown. Using the model plant, Arabidopsis thaliana, we have been exploring several regulatory mechanisms that may control auxin transport. Mutations that alter protein phosphorylation suggest that auxin transport in arabidopsis roots may be controlled via phosphorylation and this signal may facilitate gravitropic bending. The protein kinase mutant pinoid (pid9) has reduced auxin transport; whereas the protein phosphatase mutant, rcn1, has elevated transport, suggesting reciprocal regulation of auxin transport by reversible protein phosphorylation. In both of these mutants, the auxin transport defects are accompanied by gravitropic defects, linking phosphorylation signaling to gravity-induced changes in auxin transport. Additionally, auxin transport may be regulated during gravity response by changes in an endogenous auxin efflux inhibitor. Flavonoids, such as quercetin and kaempferol, have been implicated in regulation of auxin transport in vivo and in vitro. Mutants that make no flavonoids have reduced root gravitropic bending. Furthermore, changes in auxin-induced gene expression and flavonoid accumulation patterns have been observed during gravity stimulation. Current studies are examining whether there are spatial and temporal changes in flavonoid accumulation that precede gravitropic bending and whether the absence of these changes are the cause of the altered gravity response in plants with mutations that block flavonoid synthesis. These results support the idea that auxin transport may be regulated during gravity response by several mechanisms including

  9. Amyloplast Distribution Directs a Root Gravitropic Reaction

    Science.gov (United States)

    Kordyum, Elizabeth

    Immobile higher plants are oriented in the gravitational field due to gravitropim that is a physiological growth reaction and consists of three phases: reception of a gravitational signal by statocytes, its transduction to the elongation zone, and finally the organ bending. As it is known, roots are characterized with positive gravitropism, i. e. they grow in the direction of a gravitational vector, stems - with negative gravitropism, i. e. they grow in the direction opposite to a gravitational vector. According to the Nemec’s and Haberlandt’s starch-statolith hypothesis, amyloplasts in diameter of 1.5 - 3 μ in average, which appear to act as gravity sensors and fulfill a statolythic function in the specialized graviperceptive cells - statocytes, sediment in the direction of a gravitational vector in the distal part of a cell, while a nucleus is in the proximal one. There are reasonable data that confirm the amyloplasts-statoliths participation in gravity perception: 1) correlation between the statoliths localization and the site of gravity sensing, 2) significant redistribution (sedimentation) of amyloplasts in statocytes under gravistimulation in comparison with other cell organelles, 3) root decreased ability to react on gravity under starch removal from amyloplasts, 4) starchless Arabidopsis thaliana mutants are agravitropic, 5) amyloplasts-statoliths do not sediment in the absence of the gravitational vector and are in different parts or more concentrated in the center of statocytes. Plant tropisms have been intensively studied for many decades and continue to be investigated. Nevertheless, the mechanisms by which plants do so is still not clearly explained and many questions on gravisensing and graviresponse remain unanswered. Even accepted hypotheses are now being questioned and recent data are critically evaluated. Although the available data show the Ca2+ and cytoskeleton participation in graviperception and signal transduction, the clear evidence

  10. Callose deposition during gravitropism of Zea mays and Pisum sativum and its inhibition by 2-deoxy-D-glucose

    Science.gov (United States)

    Jaffe, M. J.; Leopold, A. C.

    1984-01-01

    In etiolated corn (Zea mays L.) and etiolated pea (Pisum sativum L.) seedlings, a gravitropic stimulation induces the deposition of callose. In the corn coleoptiles this occurs within 5 min of gravity stimulation, and prior to the beginning of curvature. Both gravitropic curvature and callose deposition reach their maxima by 12 h. Within the first 2 h more callose is deposited on the upper (concave) side, but after 2-3 h, this deposition pattern is reversed. An inhibitor of protein glycosylation, 2-deoxy-D-glucose (DDG), inhibits callose production and considerably retards gravitropic bending in both species of plants. Mannose can relieve the inhibition of gravitropic bending by DDG. The pea mutant "Ageotropum", which does not respond to gravity when etiolated, also fails to produce callose in response to a gravitic stimulus. These correlations indicate that callose deposition may be a biochemical component of gravitropism in plant shoots.

  11. Identification and analysis of novel genes involved in gravitropism of Arabidopsis thaliana.

    Science.gov (United States)

    Morita, Miyo T.; Tasaka, Masao; Masatoshi Taniguchi, .

    2012-07-01

    Gravitropism is a continuous control with regard to the orientation and juxtaposition of the various parts of the plant body in response to gravity. In higher plants, the relative directional change of gravity is mainly suscepted in specialized cells called statocytes, followed by signal conversion from physical information into physiological information within the statocytes. We have studied the early process of shoot gravitropism, gravity sensing and signaling process, mainly by molecular genetic approach. In Arabidopsis shoot, statocytes are the endodermal cells. sgr1/scarcrow (scr) and sgr7/short-root (shr) mutants fail to form the endodermis and to respond to gravity in their inflorescence stems. Since both SGR1/SCR and SGR7/SHR are transcriptional factors, at least a subset of their downstream genes can be expected to be involved in gravitropism. In addition, eal1 (endodermal-amyloplast less 1), which exhibits no gravitropism in inflorescence stem but retains ability to form endodermis, is a hypomorphic allele of sgr7/shr. Take advantage of these mutants, we performed DNA microarray analysis and compared gene expression profiles between wild type and the mutants. We found that approx. 40 genes were commonly down-regulated in these mutants and termed them DGE (DOWN-REGULATED GENE IN EAL1) genes. DGE1 has sequence similarity to Oryza sativa LAZY1 that is involved in shoot gravitropism of rice. DGE2 has a short region homologous to DGE1. DTL (DGE TWO-LIKE}) that has 54% identity to DGE2 is found in Arabidopsis genome. All three genes are conserved in angiosperm but have no known functional domains or motifs. We analyzed T-DNA insertion for these genes in single or multiple combinations. In dge1 dge2 dtl triple mutant, gravitropic response of shoot, hypocotyl and root dramatically reduced. Now we are carrying out further physiological and molecular genetic analysis of the triple mutant.

  12. A dwarf wheat mutant is associated with increased drought ...

    African Journals Online (AJOL)

    ... was significantly higher than Jingdong 6. Most of the s-dwarf seedlings survived in recovering experiement after water loss. The stalk of s-dwarf seedling also showed reduced gravitropism. This is the first report about a new dwarf wheat mutant associated with increased drought resistance and altered stalk gravitropism.

  13. The involvement of ethylene in regulation of Arabidopsis gravitropism

    Science.gov (United States)

    Li, Ning; Zhu, Lin

    green 1, Chen et al 2005; Guo et al 2008). To address the molecular mechanism by which ethylene regulates gravitropism, a cutting-edge phosphopro-teomics approach has been adopted to discover new components involved in ethylene signaling pathways (Li et al 2009). Two putative ethylene response transcription factors: EIL1 and ERF110, have been identified to contain ethylene-regulated phosphorylation sites, the phos-phorylation status of which are ethylene treatment-dependent but EIN2-independent, strongly suggestive of the existence of novel signaling components mediating an alternative ethylene signal pathway. Combination of the time-dependent ethylene treatments with the systematic profiling of protein phosphorylation using functional phosphoproteomics among Arabidopsis ethylene response mutants is able to provide more valuable information about the molecular mechanisms underlying ethylene and gravity signaling pathways. (This work is supported by grants: RPC07/08.SC16, 661408, 661207, N HKUST627/06, DAG04/05.SC08, HKUST6105/01M, and HKUST6413/06M)

  14. Genetic analysis of the gravitropic set-point angle in lateral roots of arabidopsis

    Science.gov (United States)

    Mullen, J. L.; Hangarter, R. P.

    2003-05-01

    Research on gravity responses in plants has mostly focused on primary roots and shoots, which typically orient to a vertical orientation. However, the distribution of lateral organs and their characteristically non-vertical growth orientation are critical for the determination of plant form. For example, in Arabidopsis, when lateral roots emerge from the primary root, they grow at a nearly horizontal orientation. As they elongate, the roots slowly curve until they eventually reach a vertical orientation. The regulation of this lateral root orientation is an important component affecting overall root system architecture. We found that this change in orientation is not simply due to the onset of gravitropic competence, as non-vertical lateral roots are capable of both positive and negative gravitropism. Thus, the horizontal growth of new lateral roots appears to be determined by what is called the gravitropic set-point angle (GSA). This developmental control of the GSA of lateral roots in Arabidopsis provides a useful system for investigating the components involved in regulating gravitropic responses. Using this system, we have identified several Arabidopsis mutants that have altered lateral root orientations but maintain normal primary root orientation.

  15. New moss species with gravitropic protonemata

    Science.gov (United States)

    Lobachevska, O. V.

    Gravitropism of 30 moss species was analysed at different stages of development: germination of spores, protonemata, gametophore and sporophyte formation. Spores were sowed in sterile conditions from the closed capsules on 1 % bactoagar with 0,2 % glucose and cultivated in the dark in vertically oriented petri dishes. In the same conditions fragments of protonemata and gametophores were grown being transferred aseptically from sterile cultures of spores germinated in controled light conditions. To assess gravity sensitivity the dishes were kept upright for 7 10 days in darkness and then 90o turned. After 20 h gravistimulation the angles of apical cell gravity bending were determined. The amount of amyloplasts and their distribution during growth and spatial reorientation of sporophytes selected from nature samples on different stages of species-specific capsule formation were analyzed after JK2J staining. The gravitropic sensing was established in 7 new moss species only. The general traits of all such species were the ark-like cygneous seta bending and inclined, to pendulous, capsules. JK2J staining of young isolated sporophytes has shown, that twisting and bending of seta as well as the spatial capsule reorientation result from the changes of distribution of amyloplasts in the direction of gravitropic growth or caused by their lateral sedimentation. In the dark protonemata of investigated mosses grew upwards on agar surface giving rise to bundles of negatively gravitropic stolons in 7-10 days. During germination at first negatively gravitropic primary chloronema and then positively gravitropic primary rizoid appeared. In 3 days, however, the growth of all primary filaments was negatively gravitropic. In Dicranella cerviculata majority of primary filaments were negatively gravitropic from the very beginning. After 20 h gravistimulation of protonemata of different moss species the following mean values of gravity bending (degrees) were established: Leptobryum

  16. Genetics of the gravitropic set-point angle in lateral organs of Arabidopsis

    Science.gov (United States)

    Mullen, J.; Hangarter, R.

    Research on gravity responses in plants has mostly focused on primary roots and shoots, which typically orient to a vertical orientation. However, the distribution of lateral organs and their typically non-vertical growth orientation are critical for the determination of plant form. For example, in Arabidopsis, when lateral roots emerge from the primary root, they grow at a nearly horizontal orientation. As they elongate, the roots slowly curve until they eventually reach a vertical orientation. The regulation of this lateral root orientation is an important component affecting the overall root system architecture. We found that this change in orientation is not simply due to the onset of gravitropic competence, as non-vertical lateral roots are capable of both positive and negative gravitropism. Thus, the horizontal growth the new lateral roots is determined by what is called the gravitropic set-point angle (GSA). This developmental control of the GSA of lateral roots in Arabidopsis provides a useful system for investigating the components involved in regulating gravitropic responses. Using this system, we have identified several Arabidopsis mutants that have altered lateral root orientations but maintain normal primary root orientation. Two of these mutants also have altered orientation of their rosette leaves, indicating some common mechanisms in the positioning of root and shoot lateral organs. Rosette leaves and lateral roots also have in common a regulation of orientation by red light that may be due to red-light-dependent changes in the GSA. Further molecular and physiological analyses of the GSA mutants will provide insight into the basis of GSA regulation and, thus, a better understanding of how gravity controls plant architecture. [This work was supported by the National Aeronautics and Space Administration through grant no. NCC 2-1200.

  17. An Arabidopsis E3 Ligase, SHOOT GRAVITROPISM9, Modulates the Interaction between Statoliths and F-Actin in Gravity Sensing[W][OA

    Science.gov (United States)

    Nakamura, Moritaka; Toyota, Masatsugu; Tasaka, Masao; Morita, Miyo Terao

    2011-01-01

    Higher plants use the sedimentation of amyloplasts in statocytes as statolith to sense the direction of gravity during gravitropism. In Arabidopsis thaliana inflorescence stem statocyte, amyloplasts are in complex movement; some show jumping-like saltatory movement and some tend to sediment toward the gravity direction. Here, we report that a RING-type E3 ligase SHOOT GRAVITROPISM9 (SGR9) localized to amyloplasts modulates amyloplast dynamics. In the sgr9 mutant, which exhibits reduced gravitropism, amyloplasts did not sediment but exhibited increased saltatory movement. Amyloplasts sometimes formed a cluster that is abnormally entangled with actin filaments (AFs) in sgr9. By contrast, in the fiz1 mutant, an ACT8 semidominant mutant that induces fragmentation of AFs, amyloplasts, lost saltatory movement and sedimented with nearly statically. Both treatment with Latrunculin B, an inhibitor of AF polymerization, and the fiz1 mutation rescued the gravitropic defect of sgr9. In addition, fiz1 decreased saltatory movement and induced amyloplast sedimentation even in sgr9. Our results suggest that amyloplasts are in equilibrium between sedimentation and saltatory movement in wild-type endodermal cells. Furthermore, this equilibrium is the result of the interaction between amyloplasts and AFs modulated by the SGR9. SGR9 may promote detachment of amyloplasts from AFs, allowing the amyloplasts to sediment in the AFs-dependent equilibrium of amyloplast dynamics. PMID:21602290

  18. Gravitropism in caulonemata of the moss Pottia intermedia

    Science.gov (United States)

    Chaban, C. I.; Kern, V. D.; Ripetskyj, R. T.; Demkiv, O. T.; Sack, F. D.

    1998-01-01

    The gravitropism of caulonemata of Pottia intermedia is described and compared with that of other mosses. Spore germination produces primary protonemata including caulonemata which give rise to buds that form the leafy moss plant, the gametophore. Primary caulonemata are negatively gravitropic but their growth and the number of filaments are limited in the dark. Axenic culture of gametophores results in the production of secondary caulonemata that usually arise near the leaf base. Secondary protonemata that form in the light are agravitropic. Secondary caulonemata that form when gametophores are placed in the dark for several days show strong negative gravitropism and grow well in the dark. When upright caulonemata are reorientated to the horizontal or are inverted, upward bending can be detected after 1 h and caulonemata reach the vertical within 1-2 d. Clear amyloplast sedimentation occurs 10-15 minutes after horizontal placement and before the start of upward curvature. This sedimentation takes place in a sub-apical zone. Amyloplast sedimentation also takes place along the length of upright and inverted Pottia protonemata. These results support the hypothesis that amyloplast sedimentation functions in gravitropic sensing since sedimentation occurs before gravitropism in Pottia and since the location and presence of a unique sedimentation zone is conserved in all four mosses known to gravitropic protonomata.

  19. Enhanced gravitropism of roots with a disrupted cap actin cytoskeleton

    Science.gov (United States)

    Hou, Guichuan; Mohamalawari, Deepti R.; Blancaflor, Elison B.

    2003-01-01

    The actin cytoskeleton has been proposed to be a major player in plant gravitropism. However, understanding the role of actin in this process is far from complete. To address this problem, we conducted an analysis of the effect of Latrunculin B (Lat B), a potent actin-disrupting drug, on root gravitropism using various parameters that included detailed curvature kinetics, estimation of gravitropic sensitivity, and monitoring of curvature development after extended clinorotation. Lat B treatment resulted in a promotion of root curvature after a 90 degrees reorientation in three plant species tested. More significantly, the sensitivity of maize (Zea mays) roots to gravity was enhanced after actin disruption, as determined from a comparison of presentation time of Lat B-treated versus untreated roots. A short 10-min gravistimulus followed by extended rotation on a 1-rpm clinostat resulted in extensive gravitropic responses, manifested as curvature that often exceeded 90 degrees. Application of Lat B to the cap or elongation zone of maize roots resulted in the disruption of the actin cytoskeleton, which was confined to the area of localized Lat B application. Only roots with Lat B applied to the cap displayed the strong curvature responses after extended clinorotation. Our study demonstrates that disrupting the actin cytoskeleton in the cap leads to the persistence of a signal established by a previous gravistimulus. Therefore, actin could function in root gravitropism by providing a mechanism to regulate the proliferation of a gravitropic signal originating from the cap to allow the root to attain its correct orientation or set point angle.

  20. Analysis of magnetic gradients to study gravitropism.

    Science.gov (United States)

    Hasenstein, Karl H; John, Susan; Scherp, Peter; Povinelli, Daniel; Mopper, Susan

    2013-01-01

    Gravitropism typically is generated by dense particles that respond to gravity. Experimental stimulation by high-gradient magnetic fields provides a new approach to selectively manipulate the gravisensing system. The movement of corn, wheat, and potato starch grains in suspension was examined with videomicroscopy during parabolic flights that generated 20 to 25 s of weightlessness. During weightlessness, a magnetic gradient was generated by inserting a wedge into a uniform, external magnetic field that caused repulsion of starch grains. The resultant velocity of movement was compared with the velocity of sedimentation under 1 g conditions. The high-gradient magnetic fields repelled the starch grains and generated a force of at least 0.6 g. Different wedge shapes significantly affected starch velocity and directionality of movement. Magnetic gradients are able to move diamagnetic compounds under weightless or microgravity conditions and serve as directional stimulus during seed germination in low-gravity environments. Further work can determine whether gravity sensing is based on force or contact between amyloplasts and statocyte membrane system.

  1. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    Science.gov (United States)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  2. Isolation of a novel mutant gene for soil-surface rooting in rice (Oryza sativa L.).

    Science.gov (United States)

    Hanzawa, Eiko; Sasaki, Kazuhiro; Nagai, Shinsei; Obara, Mitsuhiro; Fukuta, Yoshimichi; Uga, Yusaku; Miyao, Akio; Hirochika, Hirohiko; Higashitani, Atsushi; Maekawa, Masahiko; Sato, Tadashi

    2013-11-20

    Root system architecture is an important trait affecting the uptake of nutrients and water by crops. Shallower root systems preferentially take up nutrients from the topsoil and help avoid unfavorable environments in deeper soil layers. We have found a soil-surface rooting mutant from an M2 population that was regenerated from seed calli of a japonica rice cultivar, Nipponbare. In this study, we examined the genetic and physiological characteristics of this mutant. The primary roots of the mutant showed no gravitropic response from the seedling stage on, whereas the gravitropic response of the shoots was normal. Segregation analyses by using an F2 population derived from a cross between the soil-surface rooting mutant and wild-type Nipponbare indicated that the trait was controlled by a single recessive gene, designated as sor1. Fine mapping by using an F2 population derived from a cross between the mutant and an indica rice cultivar, Kasalath, revealed that sor1 was located within a 136-kb region between the simple sequence repeat markers RM16254 and 2935-6 on the terminal region of the short arm of chromosome 4, where 13 putative open reading frames (ORFs) were found. We sequenced these ORFs and detected a 33-bp deletion in one of them, Os04g0101800. Transgenic plants of the mutant transformed with the genomic fragment carrying the Os04g0101800 sequence from Nipponbare showed normal gravitropic responses and no soil-surface rooting. These results suggest that sor1, a rice mutant causing soil-surface rooting and altered root gravitropic response, is allelic to Os04g0101800, and that a 33-bp deletion in the coding region of this gene causes the mutant phenotypes.

  3. Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants

    DEFF Research Database (Denmark)

    Bastien, Renaud; Bohr, Tomas; Moulia, Bruno

    2012-01-01

    Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone...... is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies....

  4. Actin is an essential component of plant gravitropic signaling pathways

    Science.gov (United States)

    Braun, Markus; Hauslage, Jens; Limbach, Christoph

    2003-08-01

    A role of the actin cytoskeleton in the different phases of gravitropism in higher plant organs seems obvious, but experimental evidence is still inconclusive and contradictory. In gravitropically tip-growing rhizoids and protonemata, however, it is well documented that actin is an essential component of the tip-growth machinery and is involved either in the cellular mechanisms that lead to gravity sensing and in the processes of the graviresponses that result in the reorientation of the growth direction. All these processes depend on a complexly organized and highly dynamic organization of actin filaments whose diverse functions are coordinated by numerous associated proteins. Actin filaments and myosins mediate the transport of secretory vehicles to the growing tip and precisely control the delivery of cell wall material. In addition, both cell types use a very efficient actomyosin-based system to control and correct the position of their statoliths and to direct sedimenting statoliths to confined graviperception sites at the plasma membrane. The studies presented in this paper provide evidence for the essential role of actin in plant gravity sensing and the gravitropic responses. A unique actin-organizing center exists in the tip of characean rhizoids and protonemata which is associated with and dynamically regulated by a specific set of actin-dynamizing proteins. It is concluded that this highly dynamic apical actin array is an essential prerequisite for gravity sensing and gravity-oriented tip growth.

  5. The Ca2+ pump inhibitor, thapsigargin, inhibits root gravitropism in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    DANIELA C URBINA

    2006-01-01

    Full Text Available Thapsigargin, a specific inhibitor of most animal intracellular SERCA-type Ca2+ pumps present in the sarcoplasmic/endoplasmic reticulum, was originally isolated from the roots of the Mediterranean plant Thapsia gargancia L. Here, we demonstrate that this root-derived compound is capable of altering root gravitropism in Arabidopsis thaliana. Thapsigargin concentrations as low as 0.1 µM alter root gravitropism whereas under similar conditions cyclopiazonic acid does not. Furthermore, a fluorescently conjugated thapsigargin (BODIPY FL thapsigargin suggests that target sites for thapsigargin are located in intracellular organelles in the root distal elongation zone and the root cap, regions known to regulate root gravitropism

  6. Mechanisms of gravitropism in single-celled systems

    Science.gov (United States)

    Greuel, Nicole; Braun, Markus; Hauslage, Jens; Wiemann, Katharina

    Physiological processes in plants are influenced by a variety of external stimuli. Gravity is the only constant factor that provides plants with reliable information for their orientation. Gravity-oriented growth responses, called gravitropism, enable plants to adapt to a diversity of habitats on Earth and to survive changing environmental conditions. For instance, the ability to respond gravitropically prevents crop, flattened by a windstorm, from decay. Even small deviations from the genetically programmed set-point angle of plant organs are recognized by specialized cells, the statocytes, in which dense particles, the statoliths, sediment in the direction of gravity and activate gravity sensors - membrane bound gravity-receptor proteins. Activation of receptor proteins creates a physiological signal that initiates a stimulus-specific signal transduction cascade causing the gravitropic response. To unravel the gravitropic signalling pathways in plant statocytes, our research focused on a unicellular model system, the rhizoid of the green alga Chara. Experiments under microgravity conditions during sounding-rocket and parabolic plane flights have shown that the actin cytoskeleton is a key element of the gravityinduced statolith-sedimentation process in characean rhizoids. Actomyosin, consisting of a dense meshwork of mainly axially oriented actin microfilaments and motor proteins (myosins), actively guides sedimenting statoliths to gravisensitive plasma membrane areas where gravireceptor molecules are exclusively located. TEXUS and MAXUS sounding rocket missions were performed to determine the threshold acceleration level (membrane-bound gravireceptor in characean rhizoids. The results contradict the classical model of a mechanoreceptor that is activated by the pressure exerted by sedimented statoliths. Instead, the experiments provide evidence that graviperception depends on direct interactions between statoliths and a yet unknown gravireceptor.Graviperception in

  7. Auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism

    Science.gov (United States)

    Cai, Weiming; Hu, Liwei; Hu, Xiangyang; Cui, Dayong; Cai, Weiming

    Gravitropism is the asymmetric growth or curvature of plant organs in response to gravistimulation. There is a complex signal transduction cascade which involved in the differential growth of plants in response to changes in the gravity vector. The role of auxin in gravitropism has been demonstrated by many experiments, but little is known regarding the molecular details of such effects. In our studies before, mediation of the gravitropic bending of soybean roots and rice leaf sheath bases by nitric oxide, cGMP and gibberellins, are induced by auxin. The asymmetrical distribution of nitric oxide, cGMP and gibberellins resulted from the asymmetrical synthesis of them in bending sites. In soybean roots, inhibitions of NO and cGMP synthesis reduced differential NO and cGMP accumulation respectively, which both of these effects can lead to the reduction of gravitropic bending. Gibberellin-induced OsXET, OsEXPA4 and OsRWC3 were also found involved in the gravitropic bending. These data indicated that auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism. More experiments need to prove the more detailed mechanism of them.

  8. Distribution of Endogenous NO Regulates Early Gravitropic Response and PIN2 Localization in Arabidopsis Roots

    Directory of Open Access Journals (Sweden)

    Ramiro París

    2018-04-01

    Full Text Available High-resolution and automated image analysis of individual roots demonstrated that endogenous nitric oxide (NO contribute significantly to gravitropism of Arabidopsis roots. Lowering of endogenous NO concentrations strongly reduced and even reversed gravitropism, resulting in upward bending, without affecting root growth rate. Notably, the asymmetric accumulation of NO along the upper and lower sides of roots correlated with a positive gravitropic response. Detection of NO by the specific DAF-FM DA fluorescent probe revealed that NO was higher at the lower side of horizontally-oriented roots returning to initial values 2 h after the onset of gravistimulation. We demonstrate that NO promotes plasma membrane re-localization of PIN2 in epidermal cells, which is required during the early root gravitropic response. The dynamic and asymmetric localization of both auxin and NO is critical to regulate auxin polar transport during gravitropism. Our results collectively suggest that, although auxin and NO crosstalk occurs at different levels of regulation, they converge in the regulation of PIN2 membrane trafficking in gravistimulated roots, supporting the notion that a temporally and spatially coordinated network of signal molecules could participate in the early phases of auxin polar transport during gravitropism.

  9. Calcium movements and the cellular basis of gravitropism

    Science.gov (United States)

    Roux, S. J.; Biro, R. L.; Hale, C. C.

    An early gravity-transduction event in oat coleoptiles which precedes any noticeable bending is the accumulation of calcium on their prospective slower-growing side. Sub-cellular calcium localization studies indicate that the gravity-stimulated redistribution of calcium results in an increased concentration of calcium in the walls of responding cells. Since calcium can inhibit the extension growth of plant cell walls, this selective accumulation of calcium in walls may play a role in inducing the asymmetry of growth which characterizes gravitropism. The active transport of calcium from cells into walls is performed by a calcium-dependent ATPase localized in the plasma membrane. Evidence is presented in support of the hypothesis that this calcium pump is regulated by a feed-back mechanism which includes the participation of calmodulin.

  10. Effects of abscisic acid and xanthoxin on elongation and gravitropism in primary roots of Zea mays

    Science.gov (United States)

    Lee, J. S.; Hasenstein, K. H.; Mulkey, T. J.; Yang, R. L.; Evans, M. L.

    1990-01-01

    We examined the involvement of abscisic acid (ABA) and xanthoxin (Xan) in maize root gravitropism by (1) testing the ability of ABA to allow positive gravitropism in dark-grown seedlings of the maize cultivar LG11, a cultivar known to require light for positive gravitropism of the primary root, (2) comparing curvature in roots in which half of the cap had been excised and replaced with agar containing either ABA or indole-3-acetic acid (IAA), (3) measuring gravitropism in roots of seedlings submerged in oxygenated solutions of ABA or IAA and (4) testing the effect of Xan on root elongation. Using a variety of methods of applying ABA to the root, we found that ABA did not cause horizontally-oriented primary roots of dark-grown seedlings to become positively gravitropic. Replacing half of the root cap of vertically oriented roots with an agar block containing ABA had little or no effect on curvature relative to that of controls in which the half cap was replaced by a plain agar block. Replacement of the removed half cap with IAA either canceled or reversed the curvature displayed by controls. When light-grown seedlings were submerged in ABA they responded strongly to gravistimulation while those in IAA did not. Xan (up to 0.1 mM) did not affect root elongation. The results indicate that ABA is not a likely mediator of root gravitropism and that the putative ABA precursor, Xan, lacks the appropriate growth-inhibiting properties to serve as a mediator of root gravitropism.

  11. Early development and gravitropic response of lateral roots in Arabidopsis thaliana.

    Science.gov (United States)

    Guyomarc'h, S; Léran, S; Auzon-Cape, M; Perrine-Walker, F; Lucas, M; Laplaze, L

    2012-06-05

    Root system architecture plays an important role in determining nutrient and water acquisition and is modulated by endogenous and environmental factors, resulting in considerable developmental plasticity. The orientation of primary root growth in response to gravity (gravitropism) has been studied extensively, but little is known about the behaviour of lateral roots in response to this signal. Here, we analysed the response of lateral roots to gravity and, consistently with previous observations, we showed that gravitropism was acquired slowly after emergence. Using a lateral root induction system, we studied the kinetics for the appearance of statoliths, phloem connections and auxin transporter gene expression patterns. We found that statoliths could not be detected until 1 day after emergence, whereas the gravitropic curvature of the lateral root started earlier. Auxin transporters modulate auxin distribution in primary root gravitropism. We found differences regarding PIN3 and AUX1 expression patterns between the lateral root and the primary root apices. Especially PIN3, which is involved in primary root gravitropism, was not expressed in the lateral root columella. Our work revealed new developmental transitions occurring in lateral roots after emergence, and auxin transporter expression patterns that might explain the specific response of lateral roots to gravity.

  12. Gravitropism interferes with hydrotropism via counteracting auxin dynamics in cucumber roots: clinorotation and spaceflight experiments.

    Science.gov (United States)

    Morohashi, Keita; Okamoto, Miki; Yamazaki, Chiaki; Fujii, Nobuharu; Miyazawa, Yutaka; Kamada, Motoshi; Kasahara, Haruo; Osada, Ikuko; Shimazu, Toru; Fusejima, Yasuo; Higashibata, Akira; Yamazaki, Takashi; Ishioka, Noriaki; Kobayashi, Akie; Takahashi, Hideyuki

    2017-09-01

    Roots of land plants show gravitropism and hydrotropism in response to gravity and moisture gradients, respectively, for controlling their growth orientation. Gravitropism interferes with hydrotropism, although the mechanistic aspects are poorly understood. Here, we differentiated hydrotropism from gravitropism in cucumber roots by conducting clinorotation and spaceflight experiments. We also compared mechanisms regulating hydrotropism and auxin-regulated gravitropism. Clinorotated or microgravity (μG)-grown cucumber seedling roots hydrotropically bent toward wet substrate in the presence of moisture gradients, but they grew straight in the direction of normal gravitational force at the Earth's surface (1G) on the ground or centrifuge-generated 1G in space. The roots appeared to become hydrotropically more sensitive to moisture gradients under μG conditions in space. Auxin transport inhibitors significantly reduced the hydrotropic response of clinorotated seedling roots. The auxin efflux protein CsPIN5 was differentially expressed in roots of both clinorotated and μG-grown seedlings; with higher expression in the high-humidity (concave) side than the low-humidity (convex) side of hydrotropically responding roots. Our results suggest that roots become hydrotropically sensitive in μG, and CsPIN5-mediated auxin transport has an important role in inducing root hydrotropism. Thus, hydrotropic and gravitropic responses in cucumber roots may compete via differential auxin dynamics established in response to moisture gradients and gravity. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Inhibition of polar calcium movement and gravitropism in roots treated with auxin-transport inhibitors

    Science.gov (United States)

    Lee, J. S.; Mulkey, T. J.; Evans, M. L.

    1984-01-01

    Primary roots of maize (Zea mays L.) and pea (Pisum sativum L.) exhibit strong positive gravitropism. In both species, gravistimulation induces polar movement of calcium across the root tip from the upper side to the lower side. Roots of onion (Allium cepa L.) are not responsive to gravity and gravistimulation induces little or no polar movement of calcium across the root tip. Treatment of maize or pea roots with inhibitors of auxin transport (morphactin, naphthylphthalamic acid, 2,3,5-triiodobenzoic acid) prevents both gravitropism and gravity-induced polar movement of calcium across the root tip. The results indicate that calcium movement and auxin movement are closely linked in roots and that gravity-induced redistribution of calcium across the root cap may play an important role in the development of gravitropic curvature.

  14. Assessing potential targets of calcium action in light-modulated gravitropism

    Science.gov (United States)

    Roux, S. J.

    1995-01-01

    Light, through the mediation of the pigment phytochrome, modulates the gravitropic response of the shoots and roots of many plants. The transduction of both light and gravity stimuli appears to involve Ca(2+)-regulated steps, one or more of which may represent points of intersection between the two transduction chains. To be confident that Ca2+ plays a critical role in stimulus-response coupling for gravitropism, it will be important to identify specific targets of Ca2+ action whose function can be clearly linked to the regulation of growth. Calcium typically exerts its influence on cell metabolism through binding to and activating key regulatory proteins. The three best characterized of these proteins in plants are the calmodulins, calcium-dependent protein kinases, and annexins. In this review we summarize what is known about the structure and function of these proteins and speculate on how their activation by Ca2+ could influence the differential growth response of gravitropism.

  15. Interactions between red light, abscisic acid, and calcium in gravitropism

    Science.gov (United States)

    Leopold, A. C.; LaFavre, A. K.

    1989-01-01

    The effect of red light on orthogravitropism of Merit corn (Zea mays L.) roots has been attributed to its effects on the transduction phase of gravitropism (AC Leopold, SH Wettlaufer [1988] Plant Physiol 87:803-805). In an effort to characterize the orthogravitropic transduction system, comparative experiments have been carried out on the effects of red light, calcium, and abscisic acid (ABA). The red light effect can be completely satisfied with added ABA (100 micromolar) or with osmotic shock, which is presumed to increase endogenous ABA. The decay of the red light effect is closely paralleled by the decay of the ABA effect. ABA and exogenous calcium show strong additive effects when applied to either Merit or a line of corn which does not require red light for orthogravitropism. Measurements of the ABA content show marked increases in endogenous ABA in the growing region of the roots after red light. The interpretation is offered that red light or ABA may serve to increase the cytoplasmic concentrations of calcium, and that this may be an integral part of orthogravitropic transduction.

  16. An ABC transporter B family protein, ABCB19, is required for cytoplasmic streaming and gravitropism of the inflorescence stems.

    Science.gov (United States)

    Okamoto, Keishi; Ueda, Haruko; Shimada, Tomoo; Tamura, Kentaro; Koumoto, Yasuko; Tasaka, Masao; Morita, Miyo Terao; Hara-Nishimura, Ikuko

    2016-01-01

    A significant feature of plant cells is the extensive motility of organelles and the cytosol, which was originally defined as cytoplasmic streaming. We suggested previously that a three-way interaction between plant-specific motor proteins myosin XIs, actin filaments, and the endoplasmic reticulum (ER) was responsible for cytoplasmic streaming. (1) Currently, however, there are no reports of molecular components for cytoplasmic streaming other than the actin-myosin-cytoskeleton and ER-related proteins. In the present study, we found that elongated cells of inflorescence stems of Arabidopsis thaliana exhibit vigorous cytoplasmic streaming. Statistical analysis showed that the maximal velocity of plastid movements is 7.26 µm/s, which is much faster than the previously reported velocities of organelles. Surprisingly, the maximal velocity of streaming in the inflorescence stem cells was significantly reduced to 1.11 µm/s in an Arabidopsis mutant, abcb19-101, which lacks ATP BINDING CASSETTE SUBFAMILY B19 (ABCB19) that mediates the polar transport of the phytohormone auxin together with PIN-FORMED (PIN) proteins. Polar auxin transport establishes the auxin concentration gradient essential for plant development and tropisms. Deficiency of ABCB19 activity eventually caused enhanced gravitropic responses of the inflorescence stems and abnormally flexed inflorescence stems. These results suggest that ABCB19-mediated auxin transport plays a role not only in tropism regulation, but also in cytoplasmic streaming.

  17. Graviresponsiveness and abscisic-acid content of roots of carotenoid-deficient mutants of Zea mays L

    Science.gov (United States)

    Moore, R.; Smith, J. D.

    1985-01-01

    The abscisic-acid (ABA) content of roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays was analyzed using gas chromatography-mass spectrometry with an analysis sensitivity of 6 ng ABA g-1 fresh weight (FW). Roots of normal seedlings of the same lines were characterized by the following amounts of ABA (as ng ABA g-1 FW, +/- standard deviation): w-3, 279 +/- 43; vp-5, 237 +/- 26; vp-7, 338 +/- 61. We did not detect any ABA in roots of any of the mutants. Thus, the lack of carotenoids in these mutants correlated positively with the apparent absence of ABA. Primary roots of normal and mutant seedlings were positively gravitropic, with no significant differences in the curvatures of roots of normal as compared with mutant seedlings. These results indicate that ABA 1) is synthesized in maize roots via the carotenoid pathway, and 2) is not necessary for positive gravitropism by primary roots of Z. mays.

  18. Transcriptional and Hormonal Regulation of Gravitropism of Woody Stems in Populus

    Science.gov (United States)

    Suzanne Gerttula; Matthew S. Zinkgraf; Gloria K. Muday; Daniel R. Lewis; Farid M. Ibatullin; Harry Brumer; Foster Hart; Shawn D. Mansfield; Vladimir Filkov; Andrew Groover

    2015-01-01

    Angiosperm trees reorient their woody stems by asymmetrically producing a specialized xylem tissue, tension wood, which exerts a strong contractile force resulting in negative gravitropism of the stem. Here, we show, in Populus trees, that initial gravity perception and response occurs in specialized cells through sedimentation of starch-filled...

  19. Gravitropic reaction of primary seminal roots of Zea mays L. influenced by temperature and soil water potential.

    Science.gov (United States)

    Nakamoto, T

    1995-03-01

    The growth of the primary seminal root of maize (Zea mays L.) is characterized by an initial negative gravitropic reaction and a later positive one that attains a plagiotropic liminal angle. The effects of temperature and water potential of the surrounding soil on these gravitropic reactions were studied. Temperatures of 32, 25, and 18C and soil water potentials of -5, -38, and -67 kPa were imposed and the direction of growth was measured for every 1 cm length of the root. The initial negative gravitropic reaction extended to a distance of about 10 cm from the grain. Higher temperatures reduced the initial negative gravitropic reaction. Lower soil water potential induced a downward growth at root emergence. A mathematical model, in which it was assumed that the rate of the directional change of root growth was a sum of a time-dependent negative gravitropic reaction and an establishment of the liminal angle, adequately fitted the distance-angle relations. It was suggested that higher temperatures and/or a lower water potential accelerated the diminution of the initial negative gravitropic reaction.

  20. Actin cytoskeleton rearrangements in Arabidopsis roots under stress and during gravitropic response

    Science.gov (United States)

    Pozhvanov, Gregory; Medvedev, Sergei; Suslov, Dmitry; Demidchik, Vadim

    Among environmental factors, gravity vector is the only one which is constant in direction and accompanies the whole plant ontogenesis. That said, gravity vector can be considered as an essential factor for correct development of plants. Gravitropism is a plant growth response against changing its position relative to the gravity vector. It is well estableshed that gravitropism is directed by auxin redistribution across the gravistimulated organ. In addition to auxin, actin cytoskeleton was shown to be involved in gravitropism at different stages: gravity perception, signal transduction and gravitropic bending formation. However, the relationship between IAA and actin is still under discussion. In this work we studied rearrangements of actin cytoskeleton during root gravitropic response. Actin microfilaments were visualized in vivo in GFP-fABD2 transgenic Arabidopsis plants, and their angle distribution was acquired from MicroFilament Analyzer software. The curvature of actin microfilaments in root elongation zone was shown to be increased within 30-60 min of gravistimulation, the fraction of axially oriented microfilaments decreased with a concomitant increase in the fraction of oblique and transversally oriented microfilaments. In particular, the fraction of transversally oriented microfilaments (i.e. parallel to the gravity vector) increased 3-5 times. Under 10 min of sub-lethal salt stress impact, actin microfilament orientations widened from an initial axial orientation to a set of peaks at 15(°) , 45(°) and 90(°) . We conclude that the actin cytoskeleton rearrangements observed are associated with the regulation of basic mechanisms of cell extension growth by which the gravitropic bending is formed. Having common stress-related features, gravity-induced actin cytoskeleton rearrangement is slower but results in higher number of g-vector-parallel microfilaments when compared to salt stress-induced rearrangement. Also, differences in gravistimulated root

  1. Early development and gravitropic response of lateral roots in Arabidopsis thaliana

    OpenAIRE

    Guyomarc'h, S.; Leran, S.; Auzon-Cape, M.; Perrine-Walker, F.; Lucas, Mikaël; Laplaze, Laurent

    2012-01-01

    Root system architecture plays an important role in determining nutrient and water acquisition and is modulated by endogenous and environmental factors, resulting in considerable developmental plasticity. The orientation of primary root growth in response to gravity (gravitropism) has been studied extensively, but little is known about the behaviour of lateral roots in response to this signal. Here, we analysed the response of lateral roots to gravity and, consistently with previous observati...

  2. The effect of the external medium on the gravitropic curvature of rice (Oryza sativa, Poaceae) roots

    Science.gov (United States)

    Staves, M. P.; Wayne, R.; Leopold, A. C.

    1997-01-01

    The roots of rice seedlings, growing in artificial pond water, exhibit robust gravitropic curvature when placed perpendicular to the vector of gravity. To determine whether the statolith theory (in which intracellular sedimenting particles are responsible for gravity sensing) or the gravitational pressure theory (in which the entire protoplast acts as the gravity sensor) best accounts for gravity sensing in rice roots, we changed the physical properties of the external medium with impermeant solutes and examined the effect on gravitropism. As the density of the external medium is increased, the rate of gravitropic curvature decreases. The decrease in the rate of gravicurvature cannot be attributed to an inhibition of growth, since rice roots grown in 100 Osm/m3 (0.248 MPa) solutions of different densities all support the same root growth rate but inhibit gravicurvature increasingly with increasing density. By contrast, the sedimentation rate of amyloplasts in the columella cells is unaffected by the external density. These results are consistent with the gravitational pressure theory of gravity sensing, but cannot be explained by the statolith theory.

  3. Gibberellins and gravitropism in maize shoots: endogenous gibberellin-like substances and movement and metabolism of [3H]Gibberellin A20

    Science.gov (United States)

    Rood, S. B.; Kaufman, P. B.; Abe, H.; Pharis, R. P.

    1987-01-01

    [3H]Gibberellin A20 (GA20) of high specific radioactivity (49.9 gigabecquerel per millimole) was applied equilaterally in a ring of microdrops to the internodal pulvinus of shoots of 3-week-old gravistimulated and vertical normal maize (Zea mays L.), and to a pleiogravitropic (prostrate) maize mutant, lazy (la). All plants converted the [3H]GA20 to [3H]GA1- and [3H]GA29-like metabolites as well as to several metabolites with the partitioning and chromatographic behavior of glucosyl conjugates of [3H]GA1, [3H]GA29, and [3H]GA8. The tentative identification of these putative [3H]GA glucosyl conjugates was further supported by the release of the free [3H]GA moiety after cleavage with cellulase. Within 12 hours of the [3H]GA20 feed, there was a significantly higher proportion of total radioactivity in lower than in upper halves of internode and leaf sheath pulvini in gravistimulated normal maize. Further, there was a significantly higher proportion of putative free GA metabolites of [3H]GA20, especially [3H]GA1, in the lower halves of normal maize relative to upper halves. The differential localization of the metabolites between upper and lower halves was not apparent in the pleiogravitropic mutant, la. Endogenous GA-like substances were also examined in gravistimulated maize shoots. Forty-eight hours after gravistimulation of 3-week-old maize seedlings, endogenous free GA-like substances in upper and lower leaf sheath and internode pulvini halves were extracted, chromatographed, and bioassayed using the "Tanginbozu" dwarf rice microdrop assay. Lower halves contained consistently higher total levels of GA-like activity. The qualitative elution profile of GA-like substances differed consistently, upper halves containing principally a GA20-like substance and lower halves containing principally a GA20-like substance and lower halves containing mainly GA1-like and GA19-like substances. Gibberellins A1 (10 nanograms per gram) and A20 (5 nanograms per gram) were identified

  4. Gravity-dependent differentiation and root coils in Arabidopsis thaliana wild type and phospholipase-A-I knockdown mutant grown on the International Space Station.

    Science.gov (United States)

    Scherer, G F E; Pietrzyk, P

    2014-01-01

    Arabidopsis roots on 45° tilted agar in 1-g grow in wave-like figures. In addition to waves, formation of root coils is observed in several mutants compromised in gravitropism and/or auxin transport. The knockdown mutant ppla-I-1 of patatin-related phospholipase-A-I is delayed in root gravitropism and forms increased numbers of root coils. Three known factors contribute to waving: circumnutation, gravisensing and negative thigmotropism. In microgravity, deprivation of wild type (WT) and mutant roots of gravisensing and thigmotropism and circumnutation (known to slow down in microgravity, and could potentially lead to fewer waves or increased coiling in both WT and mutant). To resolve this, mutant ppla-I-1 and WT were grown in the BIOLAB facility in the International Space Station. In 1-g, roots of both types only showed waving. In the first experiment in microgravity, the mutant after 9 days formed far more coils than in 1-g but the WT also formed several coils. After 24 days in microgravity, in both types the coils were numerous with slightly more in the mutant. In the second experiment, after 9 days in microgravity only the mutant formed coils and the WT grew arcuated roots. Cell file rotation (CFR) on the mutant root surface in microgravity decreased in comparison to WT, and thus was not important for coiling. Several additional developmental responses (hypocotyl elongation, lateral root formation, cotyledon expansion) were found to be gravity-influenced. We tentatively discuss these in the context of disturbances in auxin transport, which are known to decrease through lack of gravity. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  5. Comparative effects of auxin and abscisic acid on growth, hydrogen ion efflux and gravitropism in primary roots of maize

    Science.gov (United States)

    Evans, M. L.; Mulkey, T. J.

    1984-01-01

    In order to test the idea that auxin action on root growth may be mediated by H(+) movement, the correlation of auxin action on growth and H(+) movement in roots was examined along with changes in H(+) efflux patterns associated with the asymmetric growth which occurs during gravitropism. The effects of indoleacetic acid (IAA) and abscisic acid (AbA) on growth, H(+) secretion, and gravitropism in roots were compared. Results show a close correlation existent between H(+) efflux and growth in maize roots. In intact roots there is strong H(+) efflux from the elongation zone. Growth-promoting concentrations of IAA stimulate H(+) efflux. During gravitropism the H(+) efflux from the elongation zone becomes asymmetric; the evidence indicates that auxin redistribution contributes to the development of acid efflux asymmetry. That AbA stimulates root growth is reflected in its ability to stimulate H(+) efflux from apical root segments.

  6. Diagnostic of Gravitropism-like Stabilizer of Inspection Drone Using Neural Networks

    Science.gov (United States)

    Kruglova, Tatyana; Sayfeddine, Daher; Bulgakov, Alexey

    2018-03-01

    This paper discusses the enhancement of flight stability of using an inspection drone to scan the condition of buildings on low and high altitude. Due to aerial perturbations and wakes, the drone starts to shake and may be damaged. One of the mechanical optimization methods it so add a built-in stabilizing mechanism. However, the performance of this supporting device becomes critical on certain flying heights, thus to avoid losing the drone. The paper is divided in two parts: the description of the gravitropism-like stabilizer and the diagnostic of its status using wavelet transformation and neural network classification.

  7. Inhibitory effects of KN-93, an inhibitor of Ca2+ calmodulin-dependent protein kinase II, on light-regulated root gravitropism in maize

    Science.gov (United States)

    Feldman, L. J.; Hidaka, H.

    1993-01-01

    Light is essential for root gravitropism in Zea mays L., cultivar Merit. It is hypothesized that calcium mediates this light-regulated response. KN-93, an inhibitor of calcium/calmodulin kinase II (CaMK II), inhibits light-regulated root gravitropism but does not affect light perception. We hypothesize that CaMK II, or a homologue, operates late in the light/gravity signal transduction chain. Here we provide evidence suggesting a possible physiological involvement of CaMK II in root gravitropism in plants.

  8. Promising rice mutants

    International Nuclear Information System (INIS)

    Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

    1988-01-01

    Two induced mutants namely, Mut NS 1 (tall) and Mut NS 5 (semi-dwarf) derived from rice variety Nizersail were evaluated for various agronomic characters at four locations in Bangladesh. Both the mutants matured about three weeks earlier and yielded significantly higher than the parent variety Nizersail. (author). 3 tabs., 9 refs

  9. Mutant heterosis in rice

    International Nuclear Information System (INIS)

    1987-01-01

    In the variety TKM6 a high yielding semidwarf mutant has been induced. This TKM6 mutant was used in test crosses with a number of other varieties and mutants to examine the extent of heterosis of dwarfs in rice and to select superior crosses. An excerpt of the published data is given. It appears from the backcross of the mutant with its original variety, that an increase in number of productive tillers occurs in the hybrid, leading to a striking grain yield increase, while the semi-dwarf culm length (the main mutant character) reverts to the normal phenotype. In the cross with IR8 on the other hand, there is only a minimal increase in tiller number but a substantial increase in TGW leading to more than 30% yield increase over the better parent

  10. Characterization of a calcium/calmodulin-dependent protein kinase homolog from maize roots showing light-regulated gravitropism

    Science.gov (United States)

    Lu, Y. T.; Hidaka, H.; Feldman, L. J.

    1996-01-01

    Roots of many species respond to gravity (gravitropism) and grow downward only if illuminated. This light-regulated root gravitropism is phytochrome-dependent, mediated by calcium, and inhibited by KN-93, a specific inhibitor of calcium/calmodulin-dependent protein kinase II (CaMK II). A cDNA encoding MCK1, a maize homolog of mammalian CaMK, has been isolated from roots of maize (Zea mays L.). The MCK1 gene is expressed in root tips, the site of perception for both light and gravity. Using the [35S]CaM gel-overlay assay we showed that calmodulin-binding activity of the MCK1 is abolished by 50 microM KN-93, but binding is not affected by 5 microM KN-93, paralleling physiological findings that light-regulated root gravitropism is inhibited by 50 microM KN-93, but not by 5 microM KN-93. KN-93 inhibits light-regulated gravitropism by interrupting transduction of the light signal, not light perception, suggesting that MCK1 may play a role in transducing light. This is the first report suggesting a physiological function for a CaMK homolog in light signal transduction.

  11. Disruption of the actin cytoskeleton results in the promotion of gravitropism in inflorescence stems and hypocotyls of Arabidopsis

    Science.gov (United States)

    Yamamoto, Kazuyoshi; Kiss, John Z.

    2002-01-01

    The actin cytoskeleton is hypothesized to play a major role in gravity perception and transduction mechanisms in roots of plants. To determine whether actin microfilaments (MFs) are involved in these processes in stem-like organs, we studied gravitropism in Arabidopsis inflorescence stems and hypocotyls. Localization studies using Alexa Fluor-phalloidin in conjugation with confocal microscopy demonstrated a longitudinally and transversely oriented actin MF network in endodermal cells of stems and hypocotyls. Latrunculin B (Lat-B) treatment of hypocotyls caused depolymerization of actin MFs in endodermal cells and a significant reduction of hypocotyl growth rates. Actin MFs in Lat-B-treated inflorescence stems also were disrupted, but growth rates were not affected. Despite disruption of the actin cytoskeleton in these two organs, Lat-B-treated stems and hypocotyls exhibited a promotion of gravitropic curvature in response to reorientation. In contrast, Lat-B reduced gravitropic curvature in roots but also reduced the growth rate. Thus, in contrast to prevailing hypotheses, our results suggest that actin MFs are not a necessary component of gravitropism in inflorescence stems and hypocotyls. Furthermore, this is the first study to demonstrate a prominent actin MF network in endodermal cells in the putative gravity-perceiving cells in stems.

  12. Inhibition of phospholipase C disrupts cytoskeletal organization and gravitropic growth in Arabidopsis roots.

    Science.gov (United States)

    Andreeva, Zornitza; Barton, Deborah; Armour, William J; Li, Min Y; Liao, Li-Fen; McKellar, Heather L; Pethybridge, Kylie A; Marc, Jan

    2010-10-01

    The phospholipase protein superfamily plays an important role in hormonal signalling and cellular responses to environmental stimuli. There is also growing evidence for interactions between phospholipases and the cytoskeleton. In this report we used a pharmacological approach to investigate whether inhibiting a member of the phospholipase superfamily, phospholipase C (PLC), affects microtubules and actin microfilaments as well as root growth and morphology of Arabidopsis thaliana seedlings. Inhibiting PLC activity using the aminosteroid U73122 significantly inhibited root elongation and disrupted root morphology in a concentration-dependent manner, with the response being saturated at 5 μM, whereas the inactive analogue U73343 was ineffective. The primary root appeared to lose growth directionality accompanied by root waving and formation of curls. Immunolabelling of roots exposed to increasingly higher U73122 concentrations revealed that the normal transverse arrays of cortical microtubules in the elongation zone became progressively more disorganized or depolymerized, with the disorganization appearing within 1 h of incubation. Likewise, actin microfilament arrays also were disrupted. Inhibiting PLC using an alternative inhibitor, neomycin, caused similar disruptions to both cytoskeletal organization and root morphology. In seedlings gravistimulated by rotating the culture plates by 90°, both U73122 and neomycin disrupted the normal gravitropic growth of roots and etiolated hypocotyls. The effects of PLC inhibitors are therefore consistent with the notion that, as with phospholipases A and D, PLC likewise interacts with the cytoskeleton, alters growth morphology, and is involved in gravitropism.

  13. Collection of gravitropic effectors from mucilage of electrotropically-stimulated roots of Zea mays L

    Science.gov (United States)

    Fondren, W. M.; Moore, R.

    1987-01-01

    We placed agar blocks adjacent to tips of electrotropically stimulated primary roots of Zea mays. Blocks placed adjacent to the anode-side of the roots for 3 h induced significant curvature when subsequently placed asymmetrically on tips of vertically-oriented roots. Curvature was always toward the side of the root unto which the agar block was placed. Agar blocks not contacting roots and blocks placed adjacent to the cathode-side of electrotropically stimulated roots did not induce significant curvature when placed asymmetrically on tips of vertically-oriented roots. Atomic absorption spectrophotometry indicated that blocks adjacent to the anode-side of electrotropically-stimulated roots contained significantly more calcium than (1) blocks not contacting roots, and (2) blocks contacting the cathode-side of roots. These results demonstrate the presence of a gradient of endogenous Ca in mucilage of electrotropically-stimulated roots (i.e. roots undergoing gravitropic-like curvature).

  14. Gravitropism in higher plant shoots. VI. Changing sensitivity to auxin in gravistimulated soybean hypocotyls

    Science.gov (United States)

    Rorabaugh, P. A.; Salisbury, F. B.

    1989-01-01

    Although the Cholodny-Went model of auxin redistribution has been used to explain the transduction phase of gravitropism for over 60 years, problems are apparent, especially with dicot stems. An alternative to an auxin gradient is a physiological gradient in which lower tissues of a horizontal stem become more sensitive than upper tissues to auxin already present. Changes in tissue sensitivity to auxin were tested by immersing marked Glycine max Merrill (soybean) hypocotyl sections in buffered auxin solutions (0, 10(-8) to 10(-2) molar indoleacetic acid) and observing bending and growth of upper and lower surfaces. The two surfaces of horizontal hypocotyl sections responded differently to the same applied auxin stimulus; hypocotyls bent up (lower half grew more) in buffer alone or in low auxin levels, but bent down (upper half grew more) in high auxin. Dose-response curves were evaluated with Michaelis-Menten kinetics, with auxin-receptor binding analogous to enzyme-substrate binding. Vmax for the lower half was usually greater than that for the upper half, which could indicate more binding sites in the lower half. Km of the upper half was always greater than that of the lower half (unmeasurably low), which could indicate that upper-half binding sites had a much lower affinity for auxin than lower-half sites. Dose-response curves were also obtained for sections scrubbed' (cuticle abraded) on top or bottom before immersion in auxin, and gravitropic memory' experiments of L. Brauner and A. Hagar (1958 Planta 51: 115-147) were duplicated. [1-14C]Indoleacetic acid penetration was equal into the two halves, and endogenous plus exogenously supplied (not radiolabeled) free auxin in the two halves (by gas chromatography-selected ion monitoring-mass spectrometry) was also equal. Thus, differential growth occurred without free auxin redistribution, contrary to Cholodny-Went but in agreement with a sensitivity model.

  15. Activated by Combined Magnrtic Field Gravitropic Reaction Reply on Nanodose of Biologicaly Active Compounds

    Science.gov (United States)

    Sheykina, Nadezhda; Bogatina, Nina

    The new science direction nanotechnologies initiated a big jump in the pharmacology and medicine. This leads to the big development of homeopathy. The most interest appeared while investigating of the reaction of biological object on the nano dose of iologically substances. The changing of concentration (in nmol/l) of biologically active material is also possible during weak energy action. For instance, weak combined magnetic field may change a little the concentration of ions that are oriented parallel to the external magnetic field and, by the analogy with said above, lead to the similar effects. Simple estimations give the value for the threshold to the magnetic field by two orders smaller than the geomagnetic field. By this investigation we wanted to understand whether the analogy in the action of nano dose of biologically active substances and weak combined magnetic field presents and whether the action of one of these factors may be replaced by other one. The effect of one of biologically active substances NPA (Naphtyl-Phtalame Acid) solution with the concentration 0.01 mol/l on the gravitropic reaction of cress roots was investigated. It was shown that its effect was the inhibition of cress roots gravitropic reaction. The same inhibition was achieved by the combined magnetic field action on the cress roots, germinated in water. The alternative component of the combined magnetic field coincided formally with the cyclotron frequency of NPA ions. So the analogy in the action of nano dose of biologically active substances and weak combined magnetic field was shown. The combined magnetic field using allows to decrease sufficiently the dose of biologically active substances. This fact can be of great importance in pharmacy and medicine.

  16. Productive mutants of niger

    International Nuclear Information System (INIS)

    Misra, R.C.

    2001-01-01

    Seeds of six niger (Guizotia abyssinica Cass.) varieties ('GA-10', 'ONS-8', 'IGP-72', 'N-71', 'NB-9' and 'UN-4') were treated with 0.5, 0.75 and 1% ethyl methanesulphonate. After four generations of selection, 29 mutant lines were developed and those were evaluated from 1990-92 during Kharif (July to October) and Rabi (December to March) seasons. Average plant characteristics and yield data of four high yielding mutants along with 'IGP-76' (National Check), GA-10 (Zonal Check) and 'Semiliguda Local' (Local Check) are presented

  17. Changes in root gravitropism, ultrastructure, and calcium balance of pea root statocytes induced by A23187

    Science.gov (United States)

    Belyavskaya, N.

    The role for calcium in the regulation of a wide variety of cellular events in plants is well known. Calcium signaling has been implicated in plant gravitropism. A carboxylic acid antibiotic A23187 (calcimycin) has been widely used in biological studies since it can translocate calcium across membranes. Seedlings of Pisum sativum L. cv. Uladovsky germinated in a vertically oriented cylinder of moist filter paper soaked in water during 4.5 day had been treated with 10-5 M A23187 for 12 hr. Tips of primary roots of control and A23187-treated pea seedlings were fixed for electron microscopy and electron cytochemistry. Experiments with Pisum sativum 5- day seedlings placed horizontally for 4 h after treatment with 10 μM A23187 during 12 h found that the graviresponsiveness of their primary roots was lost completely (91 % of roots) or inhibited (24 +/- 6° in comparison with 88 +/- 8° in control). At ultrastructural level, there were observed distribution of amyloplasts around the nucleus, remarkable lengthening of statocytes, advanced vacuolization, changes in dictyosome structure, ER fragmentation, cell wall thinning in A23187-treated statocytes. Cytochemical study has indicated that statocytes exposed to calcimycin have contained a number of Ca-pyroantimonate granules detected Ca 2 + ions in organelles and hyaloplasm (unlike the control ones). The deposits were mainly associated with the plasma membrane. Among organelles, mitochondria were notable for their ability to accumulate Ca 2 +. In amyloplasts, a fine precipitate was predominately located in their stroma and envelope lumens. In cell walls, deposits of the reaction product were observed along the periphery and in the median zone. Localization of electron-dense granules of lead phosphate, which indicated Ca 2 +- ATPase activities in pea statocytes exposed to A23187, was generally consistent with that in untreated roots. Apart from plasma membrane, chromatin, and nucleolus components, the cytochemical reaction

  18. Connexin mutants and cataracts

    Directory of Open Access Journals (Sweden)

    Eric C Beyer

    2013-04-01

    Full Text Available The lens is a multicellular, but avascular tissue that must stay transparent to allow normal transmission of light and focusing of it on the retina. Damage to lens cells and/or proteins can cause cataracts, opacities that disrupt these processes. The normal survival of the lens is facilitated by an extensive network of gap junctions formed predominantly of connexin46 and connexin50. Mutations of the genes that encode these connexins (GJA3 and GJA8 have been identified and linked to inheritance of cataracts in human families and mouse lines. In vitro expression studies of several of these mutants have shown that they exhibit abnormalities that may lead to disease. Many of the mutants reduce or modify intercellular communication due to channel alterations (including loss of function or altered gating or due to impaired cellular trafficking which reduces the number of gap junction channels within the plasma membrane. However, the abnormalities detected in studies of other mutants suggest that they cause cataracts through other mechanisms including gain of hemichannel function (leading to cell injury and death and formation of cytoplasmic accumulations (that may act as light scattering particles. These observations and the anticipated results of ongoing studies should elucidate the mechanisms of cataract development due to mutations of lens connexins and abnormalities of other lens proteins. They may also contribute to our understanding of the mechanisms of disease due to connexin mutations in other tissues.

  19. Apoplastic pH in corn root gravitropism: a laser scanning confocal microscopy measurement

    International Nuclear Information System (INIS)

    Taylor, D.P.; Slattery, J.; Leopold, A.C.

    1996-01-01

    The ability to measure the pH of the apoplast in situ is of special interest as a test of the cell wall acidification theory. Optical sectioning of living seedlings of corn roots using the laser scanning confocal microscope (LSCM) permits us to make pH measurements in living tissue. The pH of the apoplast of corn roots was measured by this method after infiltration with CI-NERF, a pH-sensitive dye, along with Texas Red Dextran 3000, a pH-insensitive dye, as an internal standard. In the elongation zone of corn roots, the mean apoplastic pH was 4.9. Upon gravitropic stimulation, the pH on the convex side of actively bending roots was 4.5. The lowering of the apoplastic pH by 0.4 units appears to be sufficient to account for the increased growth on that side. This technique provides site-specific evidence for the acid growth theory of cell elongation. The LSCM permits measurements of the pH of living tissues, and has a sensitivity of approximately 0.2 pH units. (author)

  20. The microtubule cytoskeleton does not integrate auxin transport and gravitropism in maize roots

    Science.gov (United States)

    Hasenstein, K. H.; Blancaflor, E. B.; Lee, J. S.

    1999-01-01

    The Cholodny-Went hypothesis of gravitropism suggests that the graviresponse is controlled by the distribution of auxin. However, the mechanism of auxin transport during the graviresponse of roots is still unresolved. To determine whether the microtubule (MT) cytoskeleton is participating in auxin transport, the cytoskeleton was examined and the movement of 3H-IAA measured in intact and excised taxol, oryzalin, and naphthylphthalamic acid (NPA)-treated roots of Zea mays cv. Merit. Taxol and oryzalin did not inhibit the graviresponse of roots but the auxin transport inhibitor NPA greatly inhibited both auxin transport and graviresponse. NPA had no effect on MT organization in vertical roots, but caused MT reorientation in horizontally placed roots. Regardless of treatment, the organization of MTs in intact roots differed from that in root segments. The MT inhibitors, taxol and oryzalin had opposite effects on the MTs, namely, depolymerization (oryzalin) and stabilization and thickening (taxol), but both treatments caused swelling of the roots. The data indicate that the MT cytoskeleton does not directly interfere with auxin transport or auxin-mediated growth responses in maize roots.

  1. Photorepair mutants of Arabidopsis

    International Nuclear Information System (INIS)

    Jiang, C.Z.; Yee, J.; Mitchell, D.L.; Britt, A.B.

    1997-01-01

    UV radiation induces two major DNA damage products, the cyclobutane pyrimidine dimer (CPD) and, at a lower frequency, the pyrimidine (6-4) pyrimidinone dimer (6-4 product). Although Escherichia coli and Saccharomyces cerevisiae produce a CPD-specific photolyase that eliminates only this class of dimer, Arabidopsis thaliana, Drosophila melanogaster, Crotalus atrox, and Xenopus laevis have recently been shown to photoreactivate both CPDs and 6-4 products. We describe the isolation and characterization of two new classes of mutants of Arabidopsis, termed uvr2 and uvr3, that are defective in the photoreactivation of CPDs and 6-4 products, respectively. We demonstrate that the CPD photolyase mutation is genetically linked to a DNA sequence encoding a type II (metazoan) CPD photolyase. In addition, we are able to generate plants in which only CPDs or 6-4 products are photoreactivated in the nuclear genome by exposing these mutants to UV light and then allowing them to repair one or the other class of dimers. This provides us with a unique opportunity to study the biological consequences of each of these two major UV-induced photoproducts in an intact living system

  2. Construindo Marcas Mutantes

    Directory of Open Access Journals (Sweden)

    Elizete De Azevedo Kreutz

    2012-09-01

    Full Text Available O presente artigo é o resultado de estudos realizados desde 2000 e busca instrumentalizar os proñssionals para a construção de Marcas Mutantes, que é   uma tendência contemporânea nas estratégias comunicacionais e de branding. Embora esta estratégia ainda não esteja consolidada, observamos que a mesma tem obtido um crescimento constante e tem sido adotadas pelas mais diferentes categorias de marcas e não apenas por aquelas direcionadas aos jovens, ao esporte, ao entretenimento, como era no principia. Com base na Hermenêutica de Profundidade de Thompson (1995, alicerçada nas pesquisas bibliográficas, de intemet, entrevistas e análise semiótica, desenhamos um método de construção de Marcas Mutantes dividido em sete fases. Como resultado, esperamos que este estudo possa auxiliar na compreensão dos processos envolvidos, ao mesmo tempo que provoque a discussão sobreo mesmo e, por consequência, o seu aprimoramento.

  3. Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

    Science.gov (United States)

    Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

    1996-01-01

    Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

  4. Isozyme differences in barley mutants

    Energy Technology Data Exchange (ETDEWEB)

    AI-Jibouri, A A.M.; Dham, K M [Department of Botany, Nuclear Research Centre, Baghdad (Iraq)

    1990-01-01

    Full text: Thirty mutants (M{sub 11}) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

  5. Isozyme differences in barley mutants

    International Nuclear Information System (INIS)

    AI-Jibouri, A.A.M.; Dham, K.M.

    1990-01-01

    Full text: Thirty mutants (M 11 ) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

  6. Inducing gravitropic curvature of primary roots of Zea mays cv Ageotropic

    Science.gov (United States)

    Moore, R.; Evans, M. L.; Fondren, W. M.

    1990-01-01

    Primary roots of the mutant 'Ageotropic' cultivar of Zea mays are nonresponsive to gravity. Their root caps secrete little or no mucilage and touch the root only at the extreme apex. A gap separates the cap and root at the periphery of the cap. Applying mucilage from normal roots or substances with a consistency similar to that of mucilage to tips of mutant roots causes these roots to become strongly graviresponsive. Gravicurvature stops when these substances are removed. Caps of some mutants secrete small amounts of mucilage and are graviresponsive. These results indicate that (a) the lack of graviresponsiveness in the mutant results from disrupting the transport pathway between the cap and root, (b) movement of the growth-modifying signal from the cap to the root occurs via an apoplastic pathway, and (c) mucilage is necessary for normal communication between the root cap and root in Zea mays cv Ageotropic.

  7. Correlations between gravitropic curvature and auxin movement across gravistimulated roots of Zea mays

    Science.gov (United States)

    Young, L. M.; Evans, M. L.; Hertel, R.

    1990-01-01

    We compared the kinetics of auxin redistribution across the caps of primary roots of 2-day-old maize (Zea mays, cv Merit) seedlings with the time course of gravitropic curvature. [3H] indoleacetic acid was applied to one side of the cap in an agar donor and radioactivity moving across the cap was collected in an agar receiver applied to the opposite side. Upon gravistimulation the roots first curved upward slightly, then returned to the horizontal and began curving downward, reaching a final angle of about 67 degrees. Movement of label across the caps of gravistimulated roots was asymmetric with preferential downward movement (ratio downward/upward = ca. 1.6, radioactivity collected during the 90 min following beginning of gravistimulation). There was a close correlation between the development of asymmetric auxin movement across the root cap and the rate of curvature, with both values increasing to a maximum and then declining as the roots approached the final angle of curvature. In roots preadapted to gravity (alternate brief stimulation on opposite flanks over a period of 1 hour) the initial phase of upward curvature was eliminated and downward bending began earlier than for controls. The correlation between asymmetric auxin movement and the kinetics of curvature also held in comparisons between control and preadapted roots. Both downward auxin transport asymmetry and downward curvature occurred earlier in preadapted roots than in controls. These findings are consistent with suggestions that the root cap is not only the site of perception but also the location of the initial redistribution of effectors that ultimately leads to curvature.

  8. Nature and origin of the calcium asymmetry-arising during gravitropic response in etiolated pea epicotyls

    International Nuclear Information System (INIS)

    Migliaccio, F.; Galston, A.W.

    1987-01-01

    Seven day old etiolated pea epicotyls were loaded symmetrically with 3 H-indole 3-acetic acid (IAA) or 45 Ca 2+ , then subjected to 1.5 hours of 1g gravistimulation. Epidermal peels taken from top and bottom surfaces after 90 minutes showed an increase in IAA on the lower side and of Ca 2+ on the upper side. Inhibitors of IAA movement (TIBA, 9-hydroxyfluorene carboxylic acid) block the development of both IAA and Ca 2+ asymmetries, but substances known to interfere with normal Ca 2+ transport do not significantly alter either IAA or Ca 2+ asymmetries. These substances, however, are active in modifying both Ca 2+ uptake and efflux through oat and pea leaf protoplast membranes. The authors conclude that the 45 Ca 2+ fed to pea epicotyls occurs largely in the cell wall, and that auxin movement is primary and Ca 2+ movement secondary in gravitropism. They hypothesize that apoplastic Ca 2+ changes during the graviresponse because it is displaced by H + secreted through auxin-induced proton release. This proposed mechanism is supported by localized pH experiments, in which filter paper soaked in various buffers was applied to one side of a carborundum-abraded epicotyls. Buffer at pH 3 increased calcium loss from the side to which it is applied, whereas pH 7 buffer decreases it. Moreover, 10 micromolar IAA and 1 micromolar fusicoccin, which promote H + efflux, increase Ca 2+ release from pea epicotyl segments, whereas cycloheximide, which inhibits H + efflux, has the reverse effect

  9. Evaluation of tall rice mutant

    International Nuclear Information System (INIS)

    Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

    1989-01-01

    One tall mutant (Mut NS1) of rice variety Nizersail was put to multilocation on-farm trial. It showed improvement over the parent in respect of by earlier maturity and higher grain yield at all locations and thus it appears as an improved mutant of Nizersail. (author). 6 refs

  10. The Swedish mutant barley collection

    International Nuclear Information System (INIS)

    1989-01-01

    Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

  11. The Swedish mutant barley collection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-07-01

    Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

  12. Mutants of alfalfa mosaic virus

    International Nuclear Information System (INIS)

    Roosien, J.

    1983-01-01

    In this thesis the isolation and characterization of a number of mutants of alfalfa mosaic virus, a plant virus with a coat protein dependent genome, is described. Thermo-sensitive (ts) mutants were selected since, at least theoretically, ts mutations can be present in all virus coded functions. It was found that a high percentage of spontaneous mutants, isolated because of their aberrant symptoms, were ts. The majority of these isolates could grow at the non-permissive temperature in the presence of a single wild type (wt) component. To increase the mutation rate virus preparations were treated with several mutagens. After nitrous acid treatment or irradiation with ultraviolet light, an increase in the level of mutations was observed. UV irradiation was preferred since it did not require large amounts of purified viral components. During the preliminary characterization of potential ts mutants the author also obtained one structural and several symptom mutants which were analysed further (chapter 7, 8 and 9). The properties of the ts mutants are described in chapter 3-7. (Auth.)

  13. Root hair mutants of barley

    International Nuclear Information System (INIS)

    Engvild, K.C.; Rasmussen, K.

    2005-01-01

    Barley mutants without root hairs or with short or reduced root hairs were isolated among M 2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M 2 seeds were sown in the field the same day. Spikes, 4-6 per M 1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

  14. Exogenous hydrogen peroxide reversibly inhibits root gravitropism and induces horizontal curvature of primary root during grass pea germination.

    Science.gov (United States)

    Jiang, Jinglong; Su, Miao; Wang, Liyan; Jiao, Chengjin; Sun, Zhengxi; Cheng, Wei; Li, Fengmin; Wang, Chongying

    2012-04-01

    During germination in distilled water (dH(2)O) on a horizontally positioned Petri dish, emerging primary roots of grass pea (Lathyrus sativus L.) grew perpendicular to the bottom of the Petri dish, due to gravitropism. However, when germinated in exogenous hydrogen peroxide (H(2)O(2)), the primary roots grew parallel to the bottom of the Petri dish and asymmetrically, forming a horizontal curvature. Time-course experiments showed that the effect was strongest when H(2)O(2) was applied prior to the emergence of the primary root. H(2)O(2) failed to induce root curvature when applied post-germination. Dosage studies revealed that the frequency of primary root curvature was significantly enhanced with increased H(2)O(2) concentrations. This curvature could be directly counteracted by dimethylthiourea (DMTU), a scavenger of H(2)O(2), but not by diphenylene iodonium (DPI) and pyridine, inhibitors of H(2)O(2) production. Exogenous H(2)O(2) treatment caused both an increase in the activities of H(2)O(2)-scavenging enzymes [including ascorbate peroxidase (APX: EC 1.11.1.11), catalase (CAT: EC 1.11.1.6) and peroxidase (POD: EC 1.11.1.7)] and a reduction in endogenous H(2)O(2) levels and root vitality. Although grass pea seeds absorbed exogenous H(2)O(2) during seed germination, DAB staining of paraffin sections revealed that exogenous H(2)O(2) only entered the root epidermis and not inner tissues. These data indicated that exogenously applied H(2)O(2) could lead to a reversible loss of the root gravitropic response and a horizontal curvature in primary roots during radicle emergence of the seedling. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  15. Mutants induced in winter rye (Secale cereale L.): Short straw-mutant No. 2714 and late-senescence mutant

    Energy Technology Data Exchange (ETDEWEB)

    Muszynski, S; Darlewska, M [Department of Plant Breeding and Seed Science, Warsaw Agricultural University, Warsaw (Poland)

    1990-01-01

    Full text: Mutants were induced by treating dormant seeds with ionizing radiation (fast neutrons) or chemicals (N-nitroso-N-ethyl urea or sodium azide). Among several mutants obtained, of special value is the short-straw mutant No. 2714 and a late senescent mutant. (author)

  16. Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1989-01-01

    Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

  17. Abscisic acid is not necessary for gravitropism in primary roots of Zea mays

    Science.gov (United States)

    Moore, R.

    1990-01-01

    Primary roots of Zea mays L. cv. Tx 5855 treated with fluridone are strongly graviresponsive, but have undetectable levels of abscisic acid (ABA). Primary roots of the carotenoid-deficient w-3, vp-5, and vp-7 mutants of Z. mays are also graviresponsive despite having undetectable amounts of ABA. Graviresponsive roots of untreated and wild-type seedlings contain 286 to 317 ng ABA g-1 f. wt, respectively. These results indicate that ABA is not necessary for root gravicurvature.

  18. Changes in cytosolic pH within Arabidopsis root columella cells play a key role in the early signaling pathway for root gravitropism

    Science.gov (United States)

    Scott, A. C.; Allen, N. S.; Davies, E. (Principal Investigator)

    1999-01-01

    Ratiometric wide-field fluorescence microscopy with 1',7'- bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF)-dextran demonstrated that gravistimulation leads to rapid changes in cytoplasmic pH (pHc) in columella cells of Arabidopsis roots. The pHc of unstimulated columella cells in tiers 2 and 3, known sites of graviperception (E.B. Blancaflor, J.B. Fasano, S. Gilroy [1998] Plant Physiol 116: 213-222), was 7.22 +/- 0.02 pH units. Following gravistimulation, the magnitude and direction of pHc changes in these cells depended on their location in the columella. Cells in the lower side of tier 2 became more alkaline by 0.4 unit within 55 s of gravistimulation, whereas alkalinization of the cells on the upper side was slower (100 s). In contrast, all cells in tier 3 acidified by 0.4 pH unit within 480 s after gravistimulation. Disrupting these pHc changes in the columella cells using pHc modifiers at concentrations that do not affect root growth altered the gravitropic response. Acidifying agents, including bafilomycin A1, enhanced curvature, whereas alkalinizing agents disrupted gravitropic bending. These results imply that pHc changes in the gravisensing cells and the resultant pH gradients across the root cap are important at an early stage in the signal cascade leading to the gravitropic response.

  19. Mutant power: using mutant allele collections for yeast functional genomics.

    Science.gov (United States)

    Norman, Kaitlyn L; Kumar, Anuj

    2016-03-01

    The budding yeast has long served as a model eukaryote for the functional genomic analysis of highly conserved signaling pathways, cellular processes and mechanisms underlying human disease. The collection of reagents available for genomics in yeast is extensive, encompassing a growing diversity of mutant collections beyond gene deletion sets in the standard wild-type S288C genetic background. We review here three main types of mutant allele collections: transposon mutagen collections, essential gene collections and overexpression libraries. Each collection provides unique and identifiable alleles that can be utilized in genome-wide, high-throughput studies. These genomic reagents are particularly informative in identifying synthetic phenotypes and functions associated with essential genes, including those modeled most effectively in complex genetic backgrounds. Several examples of genomic studies in filamentous/pseudohyphal backgrounds are provided here to illustrate this point. Additionally, the limitations of each approach are examined. Collectively, these mutant allele collections in Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans promise insights toward an advanced understanding of eukaryotic molecular and cellular biology. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Mutant genes in pea breeding

    International Nuclear Information System (INIS)

    Swiecicki, W.K.

    1990-01-01

    Full text: Mutations of genes Dpo (dehiscing pods) and A (anthocyanin synthesis) played a role in pea domestication. A number of other genes were important in cultivar development for 3 types of usage (dry seeds, green vegetable types, fodder), e.g. fn, fna, le, p, v, fas and af. New genes (induced and spontaneous), are important for present ideotypes and are registered by the Pisum Genetics Association (PGA). Comparison of a pea variety ideotype with the variation available in gene banks shows that breeders need 'new' features. In mutation induction experiments, genotype, mutagen and method of treatment (e.g. combined or fractionated doses) are varied for broadening the mutation spectrum and selecting more genes of agronomic value. New genes are genetically analysed. In Poland, some mutant varieties with the gene afila were registered, controlling lodging by a shorter stem and a higher number of internodes. Really non-lodging pea varieties could strongly increase seed yield. But the probability of detecting a major gene for lodging resistance is low. Therefore, mutant genes with smaller influence on plant architecture are sought, to combine their effect by crossing. Promising seem to be the genes rogue, reductus and arthritic as well as a number of mutant genes not yet genetically identified. The gene det for terminal inflorescence - similarly to Vicia faba - changes plant development. Utilisation of assimilates and ripening should be better. Improvement of harvest index should give higher seed yield. A number of genes controlling disease resistance are well known (eg. Fw, Fnw, En, mo and sbm). Important in mass screening of resistance are closely linked gene markers. Pea gene banks collect respective lines, but mutants induced in highly productive cultivars would be better. Inducing gene markers sometimes seems to be easier than transfer by crossing. Mutation induction in pea breeding is probably more important because a high number of monogenic features are

  1. Small RNA Deep Sequencing and the Effects of microRNA408 on Root Gravitropic Bending in Arabidopsis

    Science.gov (United States)

    Li, Huasheng; Lu, Jinying; Sun, Qiao; Chen, Yu; He, Dacheng; Liu, Min

    2015-11-01

    MicroRNA (miRNA) is a non-coding small RNA composed of 20 to 24 nucleotides that influences plant root development. This study analyzed the miRNA expression in Arabidopsis root tip cells using Illumina sequencing and real-time PCR before (sample 0) and 15 min after (sample 15) a 3-D clinostat rotational treatment was administered. After stimulation was performed, the expression levels of seven miRNA genes, including Arabidopsis miR160, miR161, miR394, miR402, miR403, miR408, and miR823, were significantly upregulated. Illumina sequencing results also revealed two novel miRNAsthat have not been previously reported, The target genes of these miRNAs included pentatricopeptide repeat-containing protein and diadenosine tetraphosphate hydrolase. An overexpression vector of Arabidopsis miR408 was constructed and transferred to Arabidopsis plant. The roots of plants over expressing miR408 exhibited a slower reorientation upon gravistimulation in comparison with those of wild-type. This result indicate that miR408 could play a role in root gravitropic response.

  2. An extra early mutant of pigeonpea

    International Nuclear Information System (INIS)

    Ravikesavan, R.; Kalaimagal, T.; Rathnaswamy, R.

    2001-01-01

    The redgram (Cajanus cajan (L.) Huth) variety 'Prabhat DT' was gamma irradiated with 100, 200, 300 and 400 Gy doses. Several mutants have been identified viz., extra early mutants, monostem mutants, obcordifoliate mutants and bi-stigmatic mutants. The extra early mutant was obtained when treated with 100 Gy dose. The mutant was selfed and forwarded from M 2 to M 4 generation. In the M 4 generation the mutant line was raised along with the parental variety. Normal cultural practices were followed and the biometrical observations were recorded. It was observed that for the characters viz., total number of branches per plant, number of pods per plants, seeds per pod, 100 seed weight and seed yield per plant there was no difference between the mutant and parent variety. Whereas, regarding the days to flowering and maturity the mutants were earlier than the parents. The observation was recorded from two hundred plants each. The mutant gives the same yield in 90 days as that of the parent variety in 107 days, which make it an economic mutant

  3. Problem-Solving Test: Tryptophan Operon Mutants

    Science.gov (United States)

    Szeberenyi, Jozsef

    2010-01-01

    This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

  4. Dwarf mutant of rice variety Seratus Malam

    International Nuclear Information System (INIS)

    Mugiono, P. S.; Soemanggono, A.M.R.

    1989-01-01

    Full text: Seeds of 'Seratus Malam', a local tall upland variety with long panicles and high yield potential were irradiated with 10-50 krad gamma rays in 1983. From 50,000 M 2 plants, 130 semidwarf mutants and 1 dwarf mutant were selected. The dwarf mutant M-362 was obtained from the 10 krad treatment. The mutant shows about 50% reduction in plant height, but also in number of productive tillers. Thus the yield per plant is also significantly less. However, the mutant gene is not allelic to DGWG and therefore may be useful in cross breeding. (author)

  5. Space-time analysis of gravitropism in etiolated Arabidopsis hypocotyls using bioluminescence imaging of the IAA19 promoter fusion with a destabilized luciferase reporter.

    Science.gov (United States)

    Yamamoto, Kotaro T; Watahiki, Masaaki K; Matsuzaki, Jun; Satoh, Soichirou; Shimizu, Hisayo

    2017-07-01

    Imaging analysis was carried out during the gravitropic response of etiolated Arabidopsis hypocotyls, using an IAA19 promoter fusion of destabilized luciferase as a probe. From the bright-field images we obtained the local deflection angle to the vertical, A, local curvature, C, and the partial derivative of C with respect to time, [Formula: see text]. These were determined every 19.9 µm along the curvilinear length of the hypocotyl, at ~10 min intervals over a period of ~6 h after turning hypocotyls through 90° to the horizontal. Similarly from the luminescence images we measured the luminescence intensity of the convex and concave flanks of the hypocotyl as well as along the median of the hypocotyl, to determine differential expression of auxin-inducible IAA19. Comparison of these parameters as a function of time and curvilinear length shows that the gravitropic response is composed of three successive elements: the first and second curving responses and a decurving response (autostraightening). The maximum of the first curving response occurs when A is 76° along the entire length of the hypocotyl, suggesting that A is the sole determinant in this response; in contrast, the decurving response is a function of both A and C, as predicted by the newly-proposed graviproprioception model (Bastien et al., Proc Natl Acad Sci USA 110:755-760, 2013). Further, differential expression of IAA19, with higher expression in the convex flank, is observed at A = 44°, and follows the Sachs' sine law. This also suggests that IAA19 is not involved in the first curving response. In summary, the gravitropic response of Arabidopsis hypocotyls consists of multiple elements that are each determined by separate principles.

  6. PNRI mutant variety: Cordyline 'Afable'

    International Nuclear Information System (INIS)

    Aurigue, Fernando B.

    2012-01-01

    Cordyline 'Afable', registered by the Philippine Nuclear Research Institute as NSIC 2009 Or-83, is an induced mutant developed from Cordyline 'Kiwi' by treating stem cuttings with acute gamma radiation from a Cobalt-60 source. The new mutant is identical to Cordyline 'Kiwi' in growth habit but differs in foliage color, and exhibits field resistance to Phytophthora sp., a fungus that causes leaf blight and rot in Ti plants. Results of this mutation breeding experiment showed that leaf color was altered by gamma irradiation and resistance to fungal diseases was improved. It also demonstrated how mutations that occur in nature may be generated artificially. Propagation of cordyline 'Afable' is true-to-type by vegetative propagation methods, such as separation of suckers and offshoots, shoot tip cutting, and top cutting. Aside from landscaping material, terrarium or dish-garden plant, it is ideal as containerized plant for indoor and outdoor use. The leaves or shoots may be harvested as cut foliage for flower arrangements. (author)

  7. Gamma ray induced mutants in Coleus

    International Nuclear Information System (INIS)

    Vasudevan, K.; Jos, J.S.

    1988-01-01

    The germplasm collection of Chinese potato (Coleus parviflorus Benth) contains almost no variation for yield contributing traits. The crop does not produce seeds. Treatment of underground tubers with 1 kR, 2 kR, 3 kR and 4 kR gamma rays resulted in 50 morphologically different mutants which are maintained as mutant clones. In the M 1 V 1 generation, suspected mutant sprouts, were carefully removed and grown separately. The most interesting mutant types are the following: (i) erect mutant with spoon shaped light green leaves, 30 cm long inflorescences against 20 cm in the control, cylindrical tubers measuring ca. 7.0 cm long and 3 cm girth against 4 cm and 2.5 cm in the control (ii) early mutants 1 and 2, one having less leaf serration, the other having light green small leaves and dwarf type (iii) fleshy leaf mutant, dark green, thick and smooth leaves. Control plants spread almost in 1 m 2 area and bear tubers from the nodes of branches. In the early mutants tuber formation is mainly restricted to the base of the plant, which makes harvest easier. The crop usually matures within 150 - 160 days, the early mutants are ready for harvest 100 days after planting. As the mutants are less spreading, the yield could be increased by closer spacing

  8. Gamma ray induced mutants in Coleus

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, K; Jos, J S [Central Tuber Crops Research Institute, Trivandrum, Kerala (India)

    1988-07-01

    The germplasm collection of Chinese potato (Coleus parviflorus Benth) contains almost no variation for yield contributing traits. The crop does not produce seeds. Treatment of underground tubers with 1 kR, 2 kR, 3 kR and 4 kR gamma rays resulted in 50 morphologically different mutants which are maintained as mutant clones. In the M{sub 1}V{sub 1} generation, suspected mutant sprouts, were carefully removed and grown separately. The most interesting mutant types are the following: (i) erect mutant with spoon shaped light green leaves, 30 cm long inflorescences against 20 cm in the control, cylindrical tubers measuring ca. 7.0 cm long and 3 cm girth against 4 cm and 2.5 cm in the control (ii) early mutants 1 and 2, one having less leaf serration, the other having light green small leaves and dwarf type (iii) fleshy leaf mutant, dark green, thick and smooth leaves. Control plants spread almost in 1 m{sup 2} area and bear tubers from the nodes of branches. In the early mutants tuber formation is mainly restricted to the base of the plant, which makes harvest easier. The crop usually matures within 150 - 160 days, the early mutants are ready for harvest 100 days after planting. As the mutants are less spreading, the yield could be increased by closer spacing.

  9. Sharing mutants and experimental information prepublication using FgMutantDb (https://scabusa.org/FgMutantDb).

    Science.gov (United States)

    Baldwin, Thomas T; Basenko, Evelina; Harb, Omar; Brown, Neil A; Urban, Martin; Hammond-Kosack, Kim E; Bregitzer, Phil P

    2018-06-01

    There is no comprehensive storage for generated mutants of Fusarium graminearum or data associated with these mutants. Instead, researchers relied on several independent and non-integrated databases. FgMutantDb was designed as a simple spreadsheet that is accessible globally on the web that will function as a centralized source of information on F. graminearum mutants. FgMutantDb aids in the maintenance and sharing of mutants within a research community. It will serve also as a platform for disseminating prepublication results as well as negative results that often go unreported. Additionally, the highly curated information on mutants in FgMutantDb will be shared with other databases (FungiDB, Ensembl, PhytoPath, and PHI-base) through updating reports. Here we describe the creation and potential usefulness of FgMutantDb to the F. graminearum research community, and provide a tutorial on its use. This type of database could be easily emulated for other fungal species. Published by Elsevier Inc.

  10. Analysis of growth patterns during gravitropic curvature in roots of Zea mays by use of a computer-based video digitizer

    Science.gov (United States)

    Nelson, A. J.; Evans, M. L.

    1986-01-01

    A computer-based video digitizer system is described which allows automated tracking of markers placed on a plant surface. The system uses customized software to calculate relative growth rates at selected positions along the plant surface and to determine rates of gravitropic curvature based on the changing pattern of distribution of the surface markers. The system was used to study the time course of gravitropic curvature and changes in relative growth rate along the upper and lower surface of horizontally-oriented roots of maize (Zea mays L.). The growing region of the root was found to extend from about 1 mm behind the tip to approximately 6 mm behind the tip. In vertically-oriented roots the relative growth rate was maximal at about 2.5 mm behind the tip and declined smoothly on either side of the maximum. Curvature was initiated approximately 30 min after horizontal orientation with maximal (50 degrees) curvature being attained in 3 h. Analysis of surface extension patterns during the response indicated that curvature results from a reduction in growth rate along both the upper and lower surfaces with stronger reduction along the lower surface.

  11. Control of gravitropic orientation. I. Non-vertical orientation by primary roots of maize results from decay of competence for orthogravitropic induction

    Science.gov (United States)

    LaMotte, Clifford E.; Pickard, Barbara G.

    2004-01-01

    Plant organs may respond to gravity by vertical (orthogravitropic), oblique (plagiogravitropic) or horizontal (diagravitropic) growth. Primary roots of maize (Zea mays L.) provide a good system for studying such behaviours because they are reportedly capable of displaying all three responses. In current work using maize seedlings of the Silver Queen cultivar, stabilisation of growth at an oblique orientation was commonplace. Hypothetically, plagiogravitropism may be accomplished either by a process we call graded orthogravitropism or by hunting about a sensed non-vertical setpoint. In graded orthotropism primary bending is unidirectional and depends on facilitative stimuli that determine its extent. The hallmark of the setpoint mechanism is restorative curvature of either sign following a displacement; both diagravitropism and orthogravitropism are based on setpoints. Roots settled in a plagiogravitropic orientation were tested with various illumination and displacement protocols designed to distinguish between these two hypotheses. The tests refuted the setpoint hypothesis and supported that of graded orthotropism. No evidence of diagravitropism could be found, thus, earlier claims were likely based on inadequately controlled observations of graded orthotropism. We propose that orthotropism is graded by the sequential action of dual gravity receptors: induction of a vectorial gravitropic response requires gravitational induction of a separate facilitative response, whose decay in the absence of fresh stimuli can brake gravitropism at plagiotropic angles.

  12. Studies on reduced height mutants in rice

    International Nuclear Information System (INIS)

    Narahari, P.; Bhagwat, S.G.

    1984-01-01

    Two cross-bred derivatives of the mutant TR5xTR17 and TR21 continued to show promise and were advanced to wider scale testing. TR5 was found to carry a semi-dwarfing gene different from that in IR8. New semi-dwarf mutants were screened from M 2 through M 4 from two separate radiation experiments. The gibberellin response of seedlings of mutant and tester strains was evaluated and crosses of tester stocks and mutant semi-dwarfs were made for genetic analyses. (author)

  13. Genetic fingerprinting of mutant rose cultivars

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Prasad, K V; Singh, K P; Singh, A.P. [Division of Floriculture and Landscaping, Indian Agricultural Research Institute, Pusa, New Delhi (India)], E-mail: kvprasad66@gmail.com

    2008-07-01

    Six rose mutants evolved at the Indian Agricultural Research Institute, New Delhi from four parent cultivars were characterized based on RAPD markers. Contrary to the earlier findings our effort has conclusively proven that the RAPD markers are indeed robust tools to discern the mutants from their parents. Among 40 primers screened, 7 primers produced inconsistent banding pattern. The number of polymorphic bands varied between 4 (OPA 14) and 10 (OPA1) with an average of 6.5 bands per primer. The percentage polymorphism ranged from 62.5 (OPM 9) to 100 percent (OPA 1). Most of the primers produced monomorphic bands between parent and mutant rose cultivars. When primer OPA 2 was used a specific band of 2.5 kb was noticed in mutant cv. Pusa Urmil and cv. Pusa Abhishek but was absent in parent cv. Jantar Mantar. A polymorphic band of 750 bp was noticed in the parent Kiss of Fire and helped in differentiating the parent from its mutant when amplified with OPK 3. Primer OPS 16 produced discriminatory band of 800 bp in mutant cv. Pink Sport of Montezuma while it was absent in its parent cv. Montezuma. Another specific band of 650 bp was present in parent cv. Montezuma and absent in its mutant cv. Pink Sport of Montezuma signifying the uniqueness of the mutant. Primer OPM 5 brought out distinct polymorphism among the parent Jantar Mantar and its three mutants with absence of a specific band of 1.5 kb in the parent. The four parents and 6 mutants were divided into four distinct groups in the Dendogram constructed by UPGMA method. The most genetically similar cultivar among the 10 cultivars analyzed are Montezuma and its pink sport of Montezuma whereas Abhisarika a mutant of cv. Kiss of Fire was distinctly different and formed a separate cluster. (author)

  14. Generation and characterization of pigment mutants of ...

    African Journals Online (AJOL)

    Compared to the wild CC-124, these mutants are characterized by a decrease in chlorophyll a & b content and an increase in carotenoids. The lowest decrease in chlorophyll a was 3 to 4 folds, while the highest increase in carotenoids was 2 to 4 folds. The result of bio-test, using the resulting pigment mutant of C. reinhardtii ...

  15. A mutant of a mutant of a mutant of a ...: Irradiation of progressive radiation-induced mutants in a mutation-breeding programme with Chrysanthenum morifolium RAM

    International Nuclear Information System (INIS)

    Broertjes, C.; Koene, P.; Veen, J.W.H. van.

    1980-01-01

    Radiation-induced sports in Chrysanthemum morifolium RAM. have been reported for several years. It has become an everyday practice to produce flower-colour mutants from outstanding cross-breeding products, even before they are distributed for the commercial production of cut flowers. One of the most successful and recent examples is that of cv. Horim, of which hundreds of mutants were produced by successive use of radiation-induced mutants in the mutation-breeding programme. Over about 4 years a variety of flower-colour mutants was obtained, not only largely including the outstanding characteristics of the original cultivar but sometimes even with an appreciable improvement in quality and yield. It is expected that the latter types, the Miros group, will soon completely supersede the spontaneous or raditation-induced Horim sports and mutants and take over the leading position of the Horim group in the production of all-year-round (AYR) cut-flowers. (orig.)

  16. Los mutantes de la escuela

    Directory of Open Access Journals (Sweden)

    Diego Armando Jaramillo-Ocampo

    2013-01-01

    Full Text Available El presente artículo muestra los resultados parciales del estudio “Juegos en el recreo escolar: un escenario para la formación ciudadana”, cuya pretensión fue comprender los imaginarios sociales de juego en el recreo escolar y su relación con la convivencia social desde la proximidad del enfoque de complementariedad y el diseño de investigación emergente, planteado por Murcia y Jaramillo (2008. Se presentan los desarrollos logrados en dos categorías centrales del estudio: el patio y el cuerpo; dos categorías que mutan constantemente como entidades vivas en la escuela, hacia la configuración de sujetos que reconocen en el otro y lo otro su posibilidad. La escuela viva, donde es posible “ser en relación con”… se reduce a un espacio temporal y físico, limitado por la campana, “el recreo”. El texto muestra, desde la voz de los actores, esa vida que se da y se quita en la escuela y que se posiciona como una más de las imposiciones normalizadas para controlar. Reconoce, finalmente, una propuesta desde la posibilidad que estos dos mutantes propician para una escuela libre y dinámica.

  17. Induction of Mutants in Durum Wheat

    International Nuclear Information System (INIS)

    AL-Ubaidi, M.; Ibrahim, I.; AL-Hadithi, A.

    2002-01-01

    This investigation presents a breeding program for induction and development of a new genotype of durum wheat, resistant to lodging with high yield, by irradiation durum wheat hybrids (F2) with gamma rays 100 Gy, during 1990-1997 cultivation seasons. This program involves: induction of variability, selection evaluation of the mutants at three locations: Twaitha (Baghdad) Latifya ( Babylon) and Swari (Kutt). All mutants showed resistance to lodging and there was a significant reduction in plant height. Mutant SIXIZ-22 surpassed other mutants and its origin in lodging resistance and plant height (83.5,82.8 and 89.4 cm) in the three locations at generation M5 and M6, respectively. Also, there were significant differences between mutant and their origin in the number of spikes/M 2 and grain yild during the two successive generation. On the other hand, mutant IZxCO-105 surpassed other mutants in the number of spikes/M 2 (231.8,242.3 and 292) and grain yield (4336,3376 and 5232 kg/ha) in all testing location, respectively . (authors) 14 refs., 4 tabs

  18. Spectrum of induced floral mutants in Petunia

    International Nuclear Information System (INIS)

    Padmaja, V.; Sudhakar, P.

    1987-01-01

    A total of six floral mutants of garden Petunia isolated from the populations raised from the seed treatment with γ-rays, 2, 4-D and sodium azide are described. Five of the mutants viz. stellata, Campyloflora, Rubriflora mixed, Grandiflora and Albiflora mixed originated as segregants in M 2 generation while the chimeral floral phenotype was expressed in M 1 generation itself. Breeding behaviour of these horticulturally interesting altered floral phenotypes were studied in subsequent generations and appropriate conclusions were drawn regarding mode of inheritance of the mutant traits. 15 refs., 4 figures, 1 table. (author)

  19. Semi-dwarf mutants for rice improvement

    International Nuclear Information System (INIS)

    Othman, Ramli; Osman, Mohammad; Ibrahim, Rusli

    1990-01-01

    Full text: MARDI and the National University of Malaysia embarked on a programme to induce resistance against blast in rice in 1978. MARDI also obtained semi dwarf mutants of cvs 'Mahsuri', 'Muda', 'Pongsu seribu' and 'Jarum Mas', which are under evaluation. The popular local rice variety 'Manik' was subjected to gamma irradiation (15-40 krad) and 101 promising semidwarf mutants have been obtained following selection in M 2 -M 6 . 29 of them show grain yields of 6.0-7.3 t/ha, compared with 5.7t for 'Manik'. Other valuable mutants were found showing long grain, less shattering, earlier maturity, and glutinous endosperm. One mutant, resistant to brown plant hopper yields 6.3t/ha. (author)

  20. X-rays sensitive mammalian cell mutant

    International Nuclear Information System (INIS)

    Utsumi, Hiroshi

    1982-01-01

    A phenomenon that in x-ray-sensitive mammalian-cell mutants, cellular death due to x-ray radiation was not increased by caffeine, but on the contrary, the dead cells were resuscitated by it was discussed. The survival rate of mutant cells increased by caffein in a low concentration. This suggested that caffeine may have induced some mechanism to produce x-ray resistant mutant cells. Postirradiation treatment with caffeine increased considerably the survival rate of the mutant cells, and this suggested the existence of latent caffeine-sensitive potentially lethal damage repair system. This system, after a few hours, is thought to be substituted by caffeine-resistant repair system which is induced by caffeine, and this may be further substituted by x-ray-resistant repair system. The repair system was also induced by adenine. (Ueda, J.)

  1. Generation and characterization of pigment mutants of ...

    African Journals Online (AJOL)

    acer

    2014-01-08

    Jan 8, 2014 ... aquatic ecosystems were studied. In the present ... logy and photosynthesis research (Stolbov, 1995;. Pedersen ... Microalgal strain and cultivation conditions ..... evaluated for their ecotoxicological effects using 124y-1 mutant.

  2. Molecular analysis of waxy mutants in rice

    International Nuclear Information System (INIS)

    Yatou, O.; Amano, E.

    1990-01-01

    Full text: The 'waxy' gene is a structural gene coding a glycosyl transferase which synthesises amylose in the endosperm tissue. 'Non-waxy' rice cultivars have an active gene and their amylose content is 18-25% depending upon gene performance and modifier genes. In 'waxy' rice, no amylose is found because the enzyme is absent. In mutants induced by gamma rays, neutrons, EI or EMS, amylose content ranged from 0 to 20%, i.e. there are intermediate phenotypes as well. Some of them had the same amount of the enzyme as a 'non-waxy' cultivar, even fully 'waxy' mutants showed a certain amount of the enzyme. This suggests that in mutants there may be no structural change in the enzyme gene but the enzyme produced might be less active. By molecular analysis of the mutants' genes it was found that only two mutants induced by thermal neutrons show structural alterations, the changes in other mutants are either too small to be detected by Southern analysis or are outside the structural gene in question. (author)

  3. Commercialization Of Orchid Mutants For Floriculture Industry

    International Nuclear Information System (INIS)

    Sakinah Ariffin; Zaiton Ahmad

    2014-01-01

    Orchids are the main contributors to cut flower industry in Malaysia with an existing good market and a huge business potential. Orchid industry has been established in Malaysia since 1960s but only started to develop and expand since 1980s. Continuous development of new orchid varieties is essential to meet customers' demands. Orchid mutagenesis research using gamma irradiation at Malaysian Nuclear Agency has successfully generated a number of new orchid varieties with commercial potentials. Therefore, Nuclear Malaysia has collaborated with an industrial partner, Hexagon Green Sdn Bhd (HGSB), to carry out commercialization research on these mutants under a Technofund project entitled 'Pre-Commercialization of Mutant Orchids for Cut Flowers Industry' from July 2011 to July 2014. Through this collaboration, Dendrobium orchid mutant plants developed by Nuclear Malaysia were transferred to HGSB's commercial orchid nursery at Bukit Changgang Agrotechnology Park, Banting, Selangor, for mass-propagation. The activities include evaluations on plant growth performance, flower quality, post harvest and market potential of these mutants. Mutants with good field performance have been identified and filed for Plant Variety Protection (PVP) with Department of Agriculture Malaysia. This paper describes outputs from this collaboration and activities undertaken in commercializing these mutants. (author)

  4. From one body mutant to one cell mutant. A progress of radiation breeding in crops

    International Nuclear Information System (INIS)

    Nagatomi, Shigeki

    1996-01-01

    An effective method was established to obtain non-chimeral mutants with wide spectrum of flower colors, regenerated from floral organs on which mutated sectors were come out on chronic irradiated plants. By this way, six mutant varieties of flower colors have been selected from one pink flower of chrysanthemum, and cultivated for cut-flower production. By the same method, 3 mutant varieties with small and spray type flowers were selected in Eustoma. Mutant varieties such as a rust disease resistant in sugarcane, 6 dwarfs in Cytisus and pure-white mushroom in velvet shank have been selected successively for short period. (J.P.N.)

  5. Gamma-radiation Mutagenesis in Genetically Unstable Barley Mutants. Pt. 2. Comparison of Various Mutants

    International Nuclear Information System (INIS)

    Balchiuniene, L.

    1995-01-01

    Spontaneous and gamma-induced mutability was compared in two groups of genetically unstable barley ear structure mutants - tweaky spike (tw) and branched ear (be). Instability in different loci causes different levels of spontaneous and gamma-induced mutability. A high spontaneous level of chlorophyll mutations is peculiar to be-ust mutants. It is suggested that the high level of induced chlorophyll mutations in allelic tw mutants is a result of better surviving of chlorophyll mutation carriers in the genotypical-physiological environment created by mutant tw alleles. (author). 6 refs., 2 tabs

  6. Officially released mutant varieties in China

    International Nuclear Information System (INIS)

    Liu, L.; Van Zanten, L.; Shu, Q.Y.; Maluszynski, M.

    2004-01-01

    The use of mutation techniques for crop improvement in China has a long and well-established tradition of more than 50 years. As the result of intensive research in many institutes dealing with application of nuclear technologies more than 620 cultivars of 44 crop species have been released. Numerous mutant varieties have been grown on a large scale bringing significant economic impact, sustaining crop production and greatly contributing to increase of food production also in stress prone areas of the country. However, there is still missing information not only on the number of mutant varieties released in particular crop species but also on mutagens applied, selection approaches and on the use of mutants in cross breeding. Numerous Chinese scientists collected and systematized this information. Results of their work were often published in local scientific journals in the Chinese language and as such were unavailable to breeders from other countries. Having this in mind, we requested Dr. Liu Luxiang, the Director of the Department of Plant Mutation Breeding and Genetics, Institute for Application of Atomic Energy, Chinese Academy of Agricultural Sciences in Beijing to help us in finding as much information as possible on mutant varieties officially released in China. The data has been collected in close collaboration with his colleagues from various institutions all over the country and then evaluated, edited and prepared for publication by our team responsible for the FAO/IAEA Database of Officially Released Mutant Varieties. We would like to thank all Chinese colleagues who contributed to this list of Chinese mutant varieties. We hope that this publication will stimulate plant breeders in China to collect more information on released mutant varieties and especially on the use of mutated genes in cross breeding. (author)

  7. Development of high yielding mutants in lentil

    International Nuclear Information System (INIS)

    Rajput, M.A.; Sarwar, G.; Siddiqui, K.A.

    2001-01-01

    Full text: Lentil (Lens culinaris Medik.) locally known as Masoor, is the second most important rabi pulse crop, after chickpea, in Pakistan. It is cultivated on an area of over 63,400 ha, which constitutes about 4.83% of the total area under pulses. The annual production of the crop is 28,200 tones with an average yield of 445 kg/ha. Yield at the national level is very low, about one-half of the world's yield, which is mainly due to non-availability of high yield potential genotypes. Keeping in view the importance of mutants in developing a large number of new varieties, an induced mutations programme was initiated at AEARC, Tandojam during 1987-88, to develop high yielding varieties in lentil. For this, seeds of two lentil varieties, 'Masoor-85' and 'ICARDA-8' had been irradiated with gamma-rays ranging from 100-600 Gy in NIAB, Faisalabad during 1990. Selections were made in M2 on the basis of earliness, plant height, branches/plant and 100 grain weight. After confirming these mutants in M3 they were promoted in station yield trials and studied continuously for three consecutive years (1993- 1995). Overall results revealed that these mutants have consistent improvement of earliness in flowering and maturity. Plant height also increased in all mutant lines except AEL 23/40/91 where reduction in this attribute was observed as compared to parent variety. Mutant lines AEL 49/20/91 and AEL 13/30/91 showed improvement in 100 grain weight. The improvement of some agronomic characters enhanced the yield of mutant lines in comparison to parent varieties (Masoor-85 and ICARDA-8). The diversity in yield over the respective parents was computed from 6.94 to 60.12%. From these encouraging results it is hoped that mutant lines like AEL 12/30/91 and AEL 49/20/91 may serve as potential lentil genotypes in future. (author)

  8. The research progress on plant mutant germplasm resources in China

    International Nuclear Information System (INIS)

    He Cexi; Ji Linzhen; Zhao Shirong

    1991-07-01

    Mutants induced by nuclear radiation or other mutagens are new artificial germplasm resources. Some mutants have been applied in plant breeding and great achievements have been reached. The status and progress on the collection, identification and utilization of mutants in China are introduced. A proposal for developing mutant germplasm resources with good agronomic characters is suggested

  9. Bacterio-opsin mutants of Halobacterium halobium

    Science.gov (United States)

    Betlach, Mary; Pfeifer, Felicitas; Friedman, James; Boyer, Herbert W.

    1983-01-01

    The bacterio-opsin (bop) gene of Halobacterium halobium R1 has been cloned with about 40 kilobases of flanking genomic sequence. The 40-kilobase segment is derived from the (G+C)-rich fraction of the chromosome and is not homologous to the major (pHH1) or minor endogenous covalently closed circular DNA species of H. halobium. A 5.1-kilobase Pst I fragment containing the bop gene was subcloned in pBR322 and a partial restriction map was determined. Defined restriction fragments of this clone were used as probes to analyze the defects associated with the bop gene in 12 bacterio-opsin mutants. Eleven out of 12 of the mutants examined had inserts ranging from 350 to 3,000 base pairs either in the bop gene or up to 1,400 base pairs upstream. The positions of the inserts were localized to four regions in the 5.1-kilobase genomic fragment: within the gene (one mutant), in a region that overlaps the 5′ end of the gene (seven mutants), and in two different upstream regions (three mutants). Two revertants of the mutant with the most distal insert had an additional insert in the same region. The polar effects of these inserts are discussed in terms of inactivation of a regulatory gene or disruption of part of a coordinately expressed operon. Given the defined nature of the bop mRNA—i.e., it has a 5′ leader sequence of three ribonucleotides—these observations indicate that the bop mRNA might be processed from a large mRNA transcript. Images PMID:16593291

  10. Chlorophyll mutants in Phaseolus vulgaris (L.) Savi

    International Nuclear Information System (INIS)

    Svetleva, D.; Petkova, S.

    1991-01-01

    Three-year investigations were conducted on chlorophyll mutants of three type: viridissima, claroviridis, flavoviridis, viridocostata and xanthomarginata produced post gamma irradiation ( 60 Co, 8 krad, 280 rad/min). Cell division rate in spectrum and in quantity of induced aberrations was found to have no significant differences with the control. Chlorophyll mutations compared to the control are less developed and their productive characters are less manifested. Cell division rate and the quantity of induced aberrations have no relation to the elements of productivity in the mutants investigated. 3 tabs., 12 refs

  11. Ethanol production using engineered mutant E. coli

    Science.gov (United States)

    Ingram, Lonnie O.; Clark, David P.

    1991-01-01

    The subject invention concerns novel means and materials for producing ethanol as a fermentation product. Mutant E. coli are transformed with a gene coding for pyruvate decarboxylase activity. The resulting system is capable of producing relatively large amounts of ethanol from a variety of biomass sources.

  12. Molecular Genetic Identification Of Some Flax Mutants

    International Nuclear Information System (INIS)

    AMER, I.M.; MOUSTAFA, H.A.M.

    2009-01-01

    Five flax genotypes (Linum usitatissimum L.) i.e., commercial cultivar Sakha 2, the mother variety Giza 4 and three mutant types induced by gamma rays, were screened for their salinity tolerance in field experiments (salinity concentration was 8600 and 8300 ppm for soil and irrigation water, respectively). Mutation 6 was the most salt tolerant as compared to the other four genotypes.RAPD technique was used to detect some molecular markers associated with salt tolerance in flax (Mut 6), RAPD-PCR results using 12 random primers exhibited 149 amplified fragments; 91.9% of them were polymorphic and twelve molecular markers (8.1%) for salt tolerant (mutant 6) were identified with molecular size ranged from 191 to 4159 bp and only eight primers successes to amplify these specific markers. Concerning the other mutants, Mut 15 and Mut 25 exhibited 4.3% and 16.2% specific markers, respectively. The induced mutants exhibited genetic similarity to the parent variety were about 51%, 58.3% and 61.1% for Mut 25, Mut 6 and Mut 15, respectively. These specific markers (SM) are used for identification of the induced mutations and it is important for new variety registration.

  13. Induced mutants for cereal grain protein improvement

    International Nuclear Information System (INIS)

    1982-01-01

    Out of 17 papers and one summary presented, six dealing with the genetic improvement of seed protein using ionizing radiations fall within the INIS subject scope. Other topics discussed were non-radiation induced mutants used for cereal grain protein improvement

  14. Male sterile mutant in Vigna radiata

    International Nuclear Information System (INIS)

    Pande, Kalpana; Raghuvanshi, S.S.

    1987-01-01

    Single and combined treatment of γ-rays and 0.25 per cent EMS were tried on Vigna radiata variety K851. A male sterile mutant was isolated in M 2 generation. Experiments indicated male sterility to be recessive and monogenic in nature. 6 figures. (author)

  15. Phanerochaete mutants with enhanced ligninolytic activity

    International Nuclear Information System (INIS)

    Kakar, S.N.; Perez, A.; Gonzales, J.

    1994-01-01

    In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organo pollutants in soils and aqueous media. Most of the organic compounds are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient starvation (e.g., nitrogen limitation). The fungus and its enzymes can thus provide alternative technologies for bioremediation, bio pulping, bio bleaching, and other industrial applications. The efficiency and effectiveness of the fungus can be enhanced by increasing production and secretion of the important enzymes in large quantities and as primary metabolites under enriched conditions. One way this can be achieved is through isolation of mutants that are deregulated, or are hyper producers or super secretors of key enzymes under enriched conditions. Through UV-light and γ-ray mutagenesis, we have isolated a variety of mutants, some of which produce key enzymes of the ligninolytic system under high-nitrogen growth conditions. One of the mutants, 76UV, produced 272 U of lignin peroxidases enzyme activity/L after 9 d under high nitrogen (although the parent strain does not produce this enzyme under these conditions). The mutant and the parent strains produced up to 54 and 62 U/L, respectively, of the enzyme activity under low nitrogen growth conditions during this period. In some experiments, the mutant showed 281 U/L of enzyme activity under high nitrogen after 17 d

  16. Gibberellins and gravitropism in maize shoots: endogenous gibberellin-like substances and movement and metabolism of [3]gibberellin A

    International Nuclear Information System (INIS)

    Rood, S.B.; Kaufman, P.B.; Abe, H.; Pharis, R.P.

    1987-01-01

    [ 3 H]Gibberellin A 20 (GA 20 ) of high specific radioactivity was applied equilaterally in a ring of microdrops to the internodal pulvinus of shoots of 3-week-old vertical normal maize (Zea mays L.), and to a pleiogravitropic (prostrate) maize mutant, lazy (la). All plants converted the [ 3 H]GA 1 - and [ 3 H]GA 29 -like metabolites as well as to several metabolites with the partitioning and chromatographic behavior of glucosyl conjugates of [ 3 H]GA 1 [ 3 H]GA 29 , and [ 3 H]GA 8 . The tentative identification of these putative [ 3 H]GA glucosyl conjugates was further supported by the release of the free [ 3 H]GA moiety after cleavage with cellulase. Within 12 hours of the [ 3 H]GA 20 feed, there was a significantly higher proportion of total radioactivity in lower than in upper halves of internode and leaf sheaf pulvini in gravistimulated normal maize. Further, there was a significantly higher proportion of putative free GA metabolites of [ 3 H]GA 20 , especially [ 3 H] GA 1 , in the lower halves of normal maize relative to upper halves. The differential localization of the metabolites between upper and lower halves was not apparent in the pleiogravitropic mutant, la. Endogenous GA-like substances were also examined in gravistimulated maize shoots. Forty-eight hours after gravistimulation of 3-week-old maize seedlings, endogenous free GA-like substances in upper and lower leaf sheath and internode pulvini halves were extracted, chromatographed, and bioassayed using the Tanginbozu dwarf rice microdroassay. Lower halves contained higher total levels of GA-like activity

  17. PNRI mutant variety: sansevieria 'Sword of Ibe'

    International Nuclear Information System (INIS)

    Aurigue, Fernando B.

    2011-01-01

    Sansevieria 'Sword of Ibe,' registered by the Philippine Nuclear Research Institute as NSIC 2008 Or-66, is a chlorophyll mutant of Sansevieria trifasciata 'Moonshine' developed by treating its suckers or shoots arising from a rhizome with acute gamma radiation from a Cobalt-60 source. The new mutant is identical in growth habit and vigor to Sansevieria 'Moonshine,' also known as Moonglow. Results of this mutation breeding experiment showed that leaf color and flowering were altered by gamma irradiation without changing the other characteristics of the plant. Propagation is true-to-type by separation of sucker and top cutting. The plant is recommended for use as landscaping material and as pot plant for indoor and outdoor use. The leaves may be harvested as cut foliage for Japanese flower arrangements. (author)

  18. Serine:glyoxylate aminotransferase mutant of barley

    International Nuclear Information System (INIS)

    Blackwell, R.; Murray, A.; Joy, K.; Lea, P.

    1987-01-01

    A photorespiratory mutant of barley (LaPr 85/84), deficient in both of the major peaks of serine:glyoxylate aminotransferase activity detected in the wild type, also lacks serine:pyruvate and asparagine:glyoxylate aminotransferase activities. Genetic analysis of the mutation demonstrated that these three activities are all carried on the same enzyme. The mutant, when placed in air, accumulated a large pool of serine, showed the expected rate (50%) of ammonia release during photorespiration but produced CO 2 at twice the wild type rate when it was fed [ 14 C] glyoxylate. Compared with the wild type, LaPr 85/84 exhibited abnormal transient changes in chlorophyll a fluorescence when the CO 2 concentration of the air was altered, indicating that the rates of the fluorescence quenching mechanisms were affected in vivo by the lack of this enzyme

  19. Intact interval timing in circadian CLOCK mutants.

    Science.gov (United States)

    Cordes, Sara; Gallistel, C R

    2008-08-28

    While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval-timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/- and -/- mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing.

  20. The application of shortened upper leaf mutant in barley breeding

    International Nuclear Information System (INIS)

    Jin Hua

    2004-01-01

    The shortened upper leaf mutant was induced from Fuji Nigo by γ-ray irradiation. Fuji Nigo, the mutant, cross-cut F 1 , F 2 and back-cross F 1 , F 2 were used to analyze mutant heredity by comparative study. The yield, chlorophyll content, light intensity, dry matter of mutant were investigated. The results showed that (1) the mutant character was controlled by a couple of nuclear genes which were partial dominance; (2) the transmittance of the mutant colony was better than that of Fuji Nigo and bottom dry matter was much more than that of Fuji Nigo; (3) under the condition of high fertilizer and high plant population , the yield of mutant was higher than that of Fuji Nigo; (4) the content of chlorophyll a in the mutant was higher than that in Fuji Nigo

  1. ''Fushi'' - excellent mutant germplasm for peanut improvement

    International Nuclear Information System (INIS)

    Jiang, X.; Zhou, Y.

    1989-01-01

    Full text: The mutant line ''Fushi'' was selected following seed treatment of the variety ''Shi Xuan 64'' in 1960 with 32 P. Many good peanut varieties were developed using ''Fushi'' in cross-breeding (ref. Mutation Breeding Newsletter No. 30 (July 1987) p. 2-3). In the past 10 years, planting areas of these varieties added up to 3,3 million ha in South China, peanut production was increased by more than 500 000 t valued 500 million Yuan. (author)

  2. Radiation induced early maturing mutants in barley

    International Nuclear Information System (INIS)

    Kumar, R.; Chauhan, S.V.S.; Sharma, R.P.

    1978-01-01

    In M 2 generation, two early maturing plants were screened from a single spike progeny of a plant obtained from 20 kR of gamma-ray irradiation of a six-rowed barley (Hordeum vulgare L. var. Jyoti). Their true breeding nature was confirmed in M 3 generation. These mutants flower and mature 38 and 22 days earlier than those of control. (auth.)

  3. Grain product of 34 soya mutant lines

    International Nuclear Information System (INIS)

    Salmeron E, J.; Mastache L, A. A.; Valencia E, F.; Diaz V, G. E.; Cervantes S, T.; De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.; Gatica T, M. A.

    2009-01-01

    This work was development with the objective of obtaining information of the agronomic behavior of 34 soya mutant lines (R 4 M 18 ) for human consumption and this way to select the 2 better lines. The genetic materials were obtained starting from the variety ISAAEG-B M2 by means of the application of recurrent radiation with Co 60 gammas, to a dose of 350 Gray for the first two generations and both later to 200 Gray and selection during 17 cycles, being obtained the 34 better lines mutants with agronomic characteristic wanted and good flavor. The obtained results were that the mutant lines L 25 and L 32 produced the major quantity in branches/plant number with 7.5 and 7.25, pods/plant number with 171.25 and 167, grains/plant number with 350.89 and 333.07 and grain product (ton/ha) to 15% of humidity 5.15 and 4.68 ton/ha, respectively. (Author)

  4. Multivariate analysis for selecting apple mutants

    International Nuclear Information System (INIS)

    Faedi, W.; Bagnara, G.L.; Rosati, P.; Cecchini, M.

    1992-01-01

    The mutlivariate analysis of four year records on several vegetative and productive traits of twenty-one apple mutants (3 of 'Jonathan', 3 of 'Ozark Gold', 14 of 'Mollie's Delicious', 1 of 'Neipling's Early Stayman)' induced by gamma radiations showed that observation of some traits of one-year-old shoots is the most efficient way to reveal compact growing apple mutants. In particular, basal cross-section area, total length and leaf area resulted the most appropriate parameters, while internode length together with conopy height and width are less appropriate. The most interesting mutants we found are: one of 'Mollie's Delicious for the best balance among tree and fruit traits and for high skin color; one of 'Neipling's Early Stayman' with an earlier and more extensively red colored apple than the original clone. (author)

  5. Probiotic features of Lactobacillus plantarum mutant strains.

    Science.gov (United States)

    Bove, Pasquale; Gallone, Anna; Russo, Pasquale; Capozzi, Vittorio; Albenzio, Marzia; Spano, Giuseppe; Fiocco, Daniela

    2012-10-01

    In this study, the probiotic potential of Lactobacillus plantarum wild-type and derivative mutant strains was investigated. Bacterial survival was evaluated in an in vitro system, simulating the transit along the human oro-gastro-intestinal tract. Interaction with human gut epithelial cells was studied by assessing bacterial adhesive ability to Caco-2 cells and induction of genes involved in innate immunity. L. plantarum strains were resistant to the combined stress at the various steps of the simulated gastrointestinal tract. Major decreases in the viability of L. plantarum cells were observed mainly under drastic acidic conditions (pH ≤ 2.0) of the gastric compartment. Abiotic stresses associated to small intestine poorly affected bacterial viability. All the bacterial strains significantly adhered to Caco-2 cells, with the ΔctsR mutant strain exhibiting the highest adhesion. Induction of immune-related genes resulted higher upon incubation with heat-inactivated bacteria rather than with live ones. For specific genes, a differential transcriptional pattern was observed upon stimulation with different L. plantarum strains, evidencing a possible role of the knocked out bacterial genes in the modulation of host cell response. In particular, cells from Δhsp18.55 and ΔftsH mutants strongly triggered immune defence genes. Our study highlights the relevance of microbial genetic background in host-probiotic interaction and might contribute to identify candidate bacterial genes and molecules involved in probiosis.

  6. Radiation studies in Cajanus cajan: meiotic behaviour in some M/sub 2/ mutants

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, S.S.N.; Akhaury, S.B. (Ranchi Univ. (India). Dept. of Botany)

    1982-01-01

    A qualitative study of the mutants produced in M/sub 2/ generation has been made. The mutants were classified as: (1) chlorophyll mutant, (2) morphological mutant, (3) pollen mutant, (4) semi-sterile and (5) sterile mutant. Cytological investigations of pollen mutants, sterile and semi-sterile mutants have revealed that these mutants generally arise at higher dose levels (20 Kr and 25 Kr).

  7. Molecular analysis of mutants of the Neurospora adenylosuccinate ...

    Indian Academy of Sciences (India)

    2012-08-07

    Aug 7, 2012 ... and mutants induced with X-ray, UV or chemical mutagens. ... We have sequenced the ad-8 locus from 13 of these mutants and identified the molecular nature ..... mutants in yeast by selection for constitutive behavior in pig-.

  8. Biological changes in Barley mutants resistant to powdery mildew disease

    International Nuclear Information System (INIS)

    Amer, I. M.; Fahim, M. M.; Moustafa, N. A.

    2012-12-01

    physiological studies showed that all kinds of chlorophyll (a), (b) and (a + b) content in infected plant were decreased while, the carotenes pigment were increased. Infection generally reduced total sugars content of all resistant mutants. Infected resistant mutant showed more phenols content and peroxidase, polyphenoloxidase activities than healthy ones of the mutants. (Author)

  9. Gamma-radiation Mutagenesis in Genetically Unstable Barley Mutants. Pt. 1. Chlorophyll Mutations in Allelic tw Mutants and Their Revertants

    International Nuclear Information System (INIS)

    Vaitkuniene, V.

    1995-01-01

    Genotypical environment is an essential factor determining the mutability of mutants of the same type. Decreased chlorophyll mutant frequency was a common characteristic of all tested tw type (tw, tw 1 , tw 2 ) mutants induced in barley c. 'Auksiniai II'. The mutability of all the tested revertants was close to that of the initial c. 'Auksiniai II'. (author). 9 refs., 2 tabs

  10. High yielding mutants of blackgram variety 'PH-25'

    International Nuclear Information System (INIS)

    Misra, R.C.; Mohapatra, B.D.; Panda, B.S.

    2001-01-01

    Seeds of blackgram (Vigna mungo L.) variety 'PH-5' were treated with chemical mutagens ethyl methanesulfonate (EMS), nitrosoguanidine (NG), maleic hydrazide (MH) and sodium azide (NaN 3 ), each at 3 different concentrations. Thirty six mutant lines developed from mutagenic treatments along with parent varieties were tested in M 4 generation. The mutants showed wide variation in most of the traits and multivariante D 2 analysis showed genetic divergence among themselves. Twenty of the thirty mutants showed genetic divergence from parent. Ten selected high yielding mutants were tested in M 5 . Yield and other productive traits of five high yielding mutants in M 4 and M 5 are presented

  11. Mutant p53 interactions with supercoiled DNA

    Czech Academy of Sciences Publication Activity Database

    Brázdová, Marie; Němcová, Kateřina; Činčárová, Lenka; Šebest, Peter; Pivoňková, Hana; Brázda, Václav; Fojta, Miroslav; Paleček, Emil

    2007-01-01

    Roč. 24, č. 6 (2007), s. 639-640 ISSN 0739-1102. [Alban 2007: The 15th Conversation . 19.06.2007-23.06.2007, Albany] R&D Projects: GA MŠk(CZ) 1K04119; GA ČR(CZ) GP204/06/P369; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : mutant p53 * supercoiled DNA * cancer Subject RIV: BO - Biophysics

  12. Radiation induced desynaptic mutants in barley

    International Nuclear Information System (INIS)

    Srivastava, H.M.

    1974-01-01

    Spontaneous occurrence of asynapsis and desynapsis has been frequently reported in a number of crop plants (Beadle 1930, 1933; Beasley and Brown 1942; Li et al. 1945; Magoon et al. 1961; Miller 1963) and other angiospermic texa (Calarier 1955; Chennaveraiah and Krisnappa 1968; Ehrenberg 1949; Johnson 1941, 1944; Roy and Jha 1958). However, there are only a few reports of induced asynapsis or desynapsis (Gottschalk and Baquar 1971; Martini and Bozzini 1966). The present paper deals with the morphology and meiotic behavior of gamma-ray induced barley mutants showing high degree of desynapsis resulting in partial to complete sterility. (author)

  13. Induction of drought tolerant mutants of rice

    International Nuclear Information System (INIS)

    El-Hissewy, A.A.; Abd Allah, A.

    2001-01-01

    The ultimate goal of crop breeding is to develop varieties with a high yield potential and desirable agronomic characteristics. In Egypt, the most important qualities sought by breeders have been high yield potential, resistance to major diseases and insects, and improved grain and eating quality. However, breeding efforts should concentrate on varieties with the potential to minimize yield losses under unfavorable conditions such as drought, and to maximize yields when conditions are favorable. Rice (Oryza sativa L.) in Egypt is completely irrigated and a significant portion of the rice cultivated area is subject to water deficit resulting from an inadequate or insufficient irrigation supply. Drought tolerance is a complex trait in that it results from the interaction of histological and physiological characters of plant with environmental factors, both above-ground and under-ground. Accordingly, root characters are closely related to drought tolerance. Little attention has been paid in Egyptian breeding programs to root characters and their relation to shoot characters. Furthermore, induced mutations are considered as one of the most important methods to induce useful mutants, especially with improved root characters, to overcome the drought problem. The present investigation aimed to study the effect of different doses of gamma rays on several characters of three Egyptian rice varieties, i.e. 'Giza 171', 'Giza 175' and 'Giza 176' and to induce one or more mutants possessing drought tolerance

  14. Indy mutants: live long and prosper

    Directory of Open Access Journals (Sweden)

    Stewart eFrankel

    2012-02-01

    Full Text Available Indy encodes the fly homologue of a mammalian transporter of di and tricarboxylatecomponents of the Krebs cycle. Reduced expression of fly Indy or two of the C. elegansIndy homologs leads to an increase in life span. Fly and worm tissues that play key roles inintermediary metabolism are also the places where Indy genes are expressed. One of themouse homologs of Indy (mIndy is mainly expressed in the liver. It has been hypothesizedthat decreased INDY activity creates a state similar to caloric restriction (CR. Thishypothesis is supported by the physiological similarities between Indy mutant flies on highcalorie food and control flies on CR, such as increased physical activity and decreases inweight, egg production, triglyceride levels, starvation resistance, and insulin signaling. Inaddition, Indy mutant flies undergo changes in mitochondrial biogenesis also observed inCR animals. Recent findings with mIndy knockout mice support and extend the findingsfrom flies. mIndy-/- mice display an increase in hepatic mitochondrial biogenesis, lipidoxidation and decreased hepatic lipogenesis. When mIndy-/- mice are fed high calorie foodthey are protected from adiposity and insulin resistance. These findings point to INDY as apotential drug target for the treatment of metabolic syndrome, type 2 diabetes and obesity.

  15. Flower morphology of Dendrobium Sonia mutants

    International Nuclear Information System (INIS)

    Sakinah Ariffin; Azhar Mohamad; Affrida Abu Hassan; Zaiton Ahmad; Mohd Nazir Basiran

    2010-01-01

    Dendrobium Sonia is a commercial hybrid which is popular as cut flower and potted plant in Malaysia. Variability in flower is important for new variety to generate more demands and choices in selection. Mutation induction is a tool in creating variability for new flower color and shape. In vitro cultures of protocorm-like bodies (PLBs) were exposed to gamma ray at dose 35 Gy. Phenotypic characteristics of the flower were observed at fully bloomed flower with emphasis on shape and color. Approximately 2000 regenerated irradiated plants were observed and after subsequent flowering, 100 plants were finally selected for further evaluation. Most of the color and shape changes are expressed in different combinations of petal, sepal and lip of the flower. In this work, 11 stable mutants were found different at flower phenotype as compared to control. Amongst these, four mutant varieties with commercial potential has been named as Dendrobium 'SoniaKeenaOval', Dendrobium 'SoniaKeenaRadiant', Dendrobium 'SoniaKeenaHiengDing' and Dendrobium 'Sonia KeenaAhmadSobri'. In this paper, variations in flower morphology and flower color were discussed, giving emphasis on variations in flower petal shape. (author)

  16. High yielding rice mutants for West Bengal

    International Nuclear Information System (INIS)

    Debnath, A.R.; Sen, S.

    1980-01-01

    Four high yielding mutants with specific genetic corrections of the simply inherited characters were developed from IR-8 through X-irradiation. Recurrent selections of the promising isolates were made under diverse agro-climatic conditions in Winter and Summer seasons of West Bengal. The isolates CNM 6 and CNM 25 belonging to early maturity group and CNM 20 and CNM 31, to mid-early maturity group were finally selected at X 5 generation on the basis of their resistance qualities, maturity period and grain yield. They were evaluated upto X 10 qeneration at multi-locations as Pre-release and Minikit Varieties at State level. They were also placed at the National Screening Nursery (NSN) for screening against multiple diseases and pests at the National level. CNM 6 is reported to be promising in IRTP nurseries. It is reported that CNM 25 (IET 5646) ranked 2nd on the basis of average grain yield, CNM 20 (IET 5937) and CNM 31 (IET 5936) were resistant to diseases and with yield comparable to Jaya. These four productive mutants of superior types are widely accepted. CNM 6 is recommended for cultivation in Bankura and Birbhum districts and CNM 25 and CNM 31 in the different agro-climatic zones of West Bengal. (author)

  17. Allosteric Mutant IDH1 Inhibitors Reveal Mechanisms for IDH1 Mutant and Isoform Selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xiaoling; Baird, Daniel; Bowen, Kimberly; Capka, Vladimir; Chen, Jinyun; Chenail, Gregg; Cho, YoungShin; Dooley, Julia; Farsidjani, Ali; Fortin, Pascal; Kohls, Darcy; Kulathila, Raviraj; Lin, Fallon; McKay, Daniel; Rodrigues, Lindsey; Sage, David; Touré, B. Barry; van der Plas, Simon; Wright, Kirk; Xu, Ming; Yin, Hong; Levell, Julian; Pagliarini, Raymond A. (Novartis)

    2017-03-01

    Oncogenic IDH1 and IDH2 mutations contribute to cancer via production of R-2-hydroxyglutarate (2-HG). Here, we characterize two structurally distinct mutant- and isoform-selective IDH1 inhibitors that inhibit 2-HG production. Both bind to an allosteric pocket on IDH1, yet shape it differently, highlighting the plasticity of this site. Oncogenic IDH1R132H mutation destabilizes an IDH1 “regulatory segment,” which otherwise restricts compound access to the allosteric pocket. Regulatory segment destabilization in wild-type IDH1 promotes inhibitor binding, suggesting that destabilization is critical for mutant selectivity. We also report crystal structures of oncogenic IDH2 mutant isoforms, highlighting the fact that the analogous segment of IDH2 is not similarly destabilized. This intrinsic stability of IDH2 may contribute to observed inhibitor IDH1 isoform selectivity. Moreover, discrete residues in the IDH1 allosteric pocket that differ from IDH2 may also guide IDH1 isoform selectivity. These data provide a deeper understanding of how IDH1 inhibitors achieve mutant and isoform selectivity.

  18. Serrated leaf mutant in mungbean (Vigna radiata (L) Wilczek)

    International Nuclear Information System (INIS)

    Malik, I.A.; Ghulam, Sarwar; Yousaf, Ali; Saleem, M.

    1988-01-01

    Dry dormant seeds of mungbean (Vigna radiata (L) Wilczek) were treated with gamma rays (15, 30 and 60 kR). The serrated leaf mutation was noticed in M 2 of cultivar Pak 32 treated with 60 kR. Cf 14 plants, 3 showed the altered leaf structure and the others were normal. The feature of this mutant was the deep serration of leaflet margins. The mutant had large thick leaflets with prominent venation. The mutant bred true in the M 3 and successive generation. Details of the morphological characteristics of the mutant are presented. The mutant exhibited slower growth particularly during the early stages of development, flowered later and attained shorter height. There was an increase in the number of pods, in seed weight and in seed protein content, but number of seed per pod was considerably reduced. The seed coat colour showed a change from green to yellowish green. In the mutant's flowers the stamina were placed much below the stigma level and the stigma sometimes protruded the corolla. Outcrossing of 4% recorded in some of the mutant lines revealed a reduced cleistogamy. The low number of seeds per pod in the mutant could be due to reduced pollen fertility. The mutant behaved as monogenic recessive. The symbols SL/sl are proposed for this allelic pair. The mutant may have use as a green manure crop because of its large foliage and for the breeders as a genetic marker

  19. Characterization of a Weak Allele of Zebrafish cloche Mutant

    Science.gov (United States)

    Ma, Ning; Huang, Zhibin; Chen, Xiaohui; He, Fei; Wang, Kun; Liu, Wei; Zhao, Linfeng; Xu, Xiangmin; Liao, Wangjun; Ruan, Hua; Luo, Shenqiu; Zhang, Wenqing

    2011-01-01

    Hematopoiesis is a complicated and dynamic process about which the molecular mechanisms remain poorly understood. Danio rerio (zebrafish) is an excellent vertebrate system for studying hematopoiesis and developmental mechanisms. In the previous study, we isolated and identified a cloche 172 (clo 172) mutant, a novel allele compared to the original cloche (clo) mutant, through using complementation test and initial mapping. Here, according to whole mount in-situ hybridization, we report that the endothelial cells in clo 172 mutant embryos, although initially developed, failed to form the functional vascular system eventually. In addition, further characterization indicates that the clo 172 mutant exhibited weaker defects instead of completely lost in primitive erythroid cells and definitive hematopoietic cells compared with the clo s5 mutant. In contrast, primitive myeloid cells were totally lost in clo 172 mutant. Furthermore, these reappeared definitive myeloid cells were demonstrated to initiate from the remaining hematopoietic stem cells (HSCs) in clo 172 mutant, confirmed by the dramatic decrease of lyc in clo 172 runx1w84x double mutant. Collectively, the clo 172 mutant is a weak allele compared to the clo s5 mutant, therefore providing a model for studying the early development of hematopoietic and vascular system, as well as an opportunity to further understand the function of the cloche gene. PMID:22132109

  20. Mutants of Cercospora kikuchii altered in cercosporin synthesis and pathogenicity

    International Nuclear Information System (INIS)

    Upchurch, R.G.; Walker, D.C.; Rollins, J.A.; Ehrenshaft, M.; Daub, M.E.

    1991-01-01

    The authors have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus

  1. Temperature sensitive riboflavin mutants of Penicillium vermiculatum Dangeard

    International Nuclear Information System (INIS)

    Mitra, J.; Chaudhari, K.L.

    1974-01-01

    Two temperature sensitive UV induced riboflavin mutants rib 1 and rib 6 have been physiologically and genetically characterized. The two mutants behave differently with regard to their temperature sensitivity. The rib 1 mutant exhibits a leaky growth in minimal medium between 15 0 C and 30 0 C but grows well when the medium is supplemented with riboflavin. At 35 0 C the growth response of the mutant is at its max. and at 40 0 C and below 15 0 C it ceases to grow. The rib 6 mutant which is red brown in colour shows wild type character at temp. below 25 0 C in minimal medium but requires riboflavin at 30 0 C and above. Heterokaryotic analysis revealed the nonallelic nature of the two temperature mutants. Genetic tests of allelic relationship between riboflavin markers by crossing were also done. (author)

  2. Some mutants in maize obtained by irradiation with thermal neutrons

    International Nuclear Information System (INIS)

    Diaconu, P.

    1993-01-01

    Irradiation was carried out at the Bucharest Institute of Atomic Physics and the National Laboratory Brookhaven, USA. A description is given of 22 genic mutants affecting leaf color, plant size, and branching capacity. Characteristics related to pollen fertility and the vegetative period were affected in all the mutants. Improvement of pollen fertility was attempted over four generations without success. The maize mutants obtained by irradiation may be considered as being without practical significance. (author). 7 figs., 1 tab. 11 ref

  3. Chemotaxis-defective mutants of the nematode Caenorhabditis elegans.

    Science.gov (United States)

    Dusenbery, D B; Sheridan, R E; Russell, R L

    1975-06-01

    The technique of countercurrent separation has been used to isolate 17 independent chemotaxis-defective mutants of the nematode Caenorhabditis elegans. The mutants, selected to be relatively insensitive to the normally attractive salt NaCl, show varying degrees of residual sensitivity; some are actually weakly repelled by NaCl. The mutants are due to single gene defects, are autosomal and recessive, and identify at least five complementation groups.

  4. Study on ionizing radiosensitivity of respiratory deficiency yeast mutants

    International Nuclear Information System (INIS)

    Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei

    2006-01-01

    The radiosensitivity of respiratory deficiency yeast mutants has been studied in this work. The mutants which were screened from the yeasts after ionizing irradiation were irradiated with 12 C 6+ at different doses. Because of the great change in its mitochondria and mitochondrial DNA, the respiratory deficiency yeast mutants show radio-sensitivity at dose less than 1 Gy and radioresistance at doses higher than 1 Gy. (authors)

  5. Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

    OpenAIRE

    Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

    2010-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

  6. Studies on mutant breeding of Hibiscus syriacus

    International Nuclear Information System (INIS)

    Song, Hi Sup; Kim, Jin Kyu; Lee, Ki Un; Kim, Young Taik.

    1997-01-01

    Hibiscus has been known as a national flower of Korea. Hibiscus has such a characteristic of self-incompatibility that all the plant exist as natural hybrids and have heterogeneous genes. Many domestic 91 varieties of Hibiscus syriacus were collected. Radiosensitivity of H. Syriacus irradiated with γ-ray was investigated in plant cuttings. The plant height was reduced by 45% in 5KR irradiated group, compared to control group. The radiation dose of 5KR could be recommended for mutation breeding of Hibiscus cuttings. Radiosensitivity of γ-ray irradiated Hibiscus seed were investigated. The germination rate, survival rate and plant height was better in the 4KR irradiation plot than control. The radiation dose of 10∼12KR are recommended for mutation breeding of Hibiscus. Promising mutant lines were selected form the varieties of Hwarang, Wolsan no. 176, Ilpyondansim, Emille, Hanol, Yongkwang, Saeyongkwang, Chungmu, Imjinhong, Arang, Hungdansim-1 and Hongdansim-2. (author). 66 refs., 16 tabs., 13 figs

  7. Google: a narrativa de uma marca mutante

    Directory of Open Access Journals (Sweden)

    Elizete de Azevedo Kreutz

    2010-01-01

    Full Text Available As marcas mutantes já fazem parte de nossa realidade, embora ainda não totalmente percebidas e/ou aceitas como tal. O presente artigo busca refletir sobre a relevância dessas novas estratégias de comunicação e branding, identificando suas principais características. Para isso, utilizamos o método de estudo de caso, o Google, ancorado nos métodos de pesquisa bibliográfica e de internet. A escolha foi intencional, posto que a organização é referência em sua categoria, mecanismo de busca, e reflete essa estratégia comunicacional contemporânea. Como resultado, as informações obtidas nos possibilitam compreender essa tendência de comportamento de marca que busca a interação com seus públicos.

  8. Studies on mutant breeding of Hibiscus syriacus

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hi Sup; Kim, Jin Kyu; Lee, Ki Un; Kim, Young Taik

    1997-01-01

    Hibiscus has been known as a national flower of Korea. Hibiscus has such a characteristic of self-incompatibility that all the plant exist as natural hybrids and have heterogeneous genes. Many domestic 91 varieties of Hibiscus syriacus were collected. Radiosensitivity of H. Syriacus irradiated with {gamma}-ray was investigated in plant cuttings. The plant height was reduced by 45% in 5KR irradiated group, compared to control group. The radiation dose of 5KR could be recommended for mutation breeding of Hibiscus cuttings. Radiosensitivity of {gamma}-ray irradiated Hibiscus seed were investigated. The germination rate, survival rate and plant height was better in the 4KR irradiation plot than control. The radiation dose of 10{approx}12KR are recommended for mutation breeding of Hibiscus. Promising mutant lines were selected form the varieties of Hwarang, Wolsan no. 176, Ilpyondansim, Emille, Hanol, Yongkwang, Saeyongkwang, Chungmu, Imjinhong, Arang, Hungdansim-1 and Hongdansim-2. (author). 66 refs., 16 tabs., 13 figs.

  9. Recombination-deficient mutants of Bacillus subtilis

    International Nuclear Information System (INIS)

    Sadaie, Y.; Kada, T.

    1976-01-01

    Two mutant strains of Bacillus subtilis Marburg, NIG43 and NIG45, were isolated. They showed high sensitivities to gamma rays, ultraviolet light (uv), and chemicals. Deficiencies in genetic recombination of these two mutants were shown by the experiments on their capacity in transformation, SPO2 transfection, and PBS1 phage transduction, as well as on their radiation and drug sensitivities and their Hcr + capacity for uv-exposed phage M2. Some of these characteristics were compared with those of the known strains possessing the recA1 or recB2 alleles. Mapping studies revealed that the mutation rec-43 of strain NIG43 lies in the region of chromosome replication origin. The order was purA dna-8132 rec-43. Another mutation, rec-45, of strain NIG45 was found to be tightly linked to recA1. The mutation rec-43 reduced mainly the frequency of PBS1 transduction. On the other hand, the mutation rec-45 reduced the frequency of recombination involved both in transformation and PBS1 tranduction. The mutation rec-43 of strain NIG43 is conditional, but rec-45 of strain NIG45 is not. The uv impairment in cellular survival of strain NIG43 was gradually reverted at higher salt or sucrose concentrations, suggesting cellular possession of a mutated gene product whose function is conditional. In contrast to several other recombination-deficient strains, SPO2 lysogens of strains NIG43 and NIG45 were not inducible, indicating involvement of rec-43 + or rec-45 + gene product in the development of SPO2 prophage to a vegetative form. The uv-induced deoxyribonucleic acid degradation in vegetative cells was higher in rec-43 and rec-45 strains

  10. Winter barley mutants created in the Ukraine

    International Nuclear Information System (INIS)

    Zayats, O.M.

    2001-01-01

    Full text: Increasing fodder and protein production is one of the objectives of the development of agriculture in Ukraine. Higher productivity of fodder crops, due to new highly productive varieties, is the means to meet this aim. Winter barley is an important crop for fodder purposes. The climate of the Ukraine is favourable for growing this crop. The areas used for the growth of winter barley are however, small (500,000-550,000 ha) and there is a shortage of good quality varieties. The main aim of the work was therefore to create new varieties of highly productive winter barley, of good quality. The new varieties and mutation lines of winter barley were created under the influence of water solutions of N-nitroso-N-methylurea (NMH - 0,012, 0,005%), N-nitroso-N-ethylurea (NEH - 0,05; 0.025; 0,012%) ethyleneimine (EI - 0,02; 0,01; 0,005%) on winter barley seeds of the varieties of local and foreign selections. On the basis of many years of investigations (1984-94) the following mutations were described: hard-grained, winter-hardiness, earliness, middle-maturity, late-maturity, wide and large leaves, narrow leaves, multinodal, great number of leaves, great number of flowers, strong stem (lodging resistant), tallness, semi-dwarfness, dwarfness, and high productivity. Particularly valuable are mutants with high productivity of green bulk. Their potential yield is 70 t/ha. As a result of the work two varieties of winter barley 'Shyrokolysty' and 'Kormovy' were released into the State register of plant varieties of the Ukraine. The other valuable mutant genotypes are used in cross breeding programmes. (author)

  11. Isoenzymes performance of some rice varieties and their mutants

    International Nuclear Information System (INIS)

    Winarno, Ermin; Suliwarno, Ambyah; Ismachin, M.

    1992-01-01

    Isoenzymes performance of some rice varieties and their mutants. Genetics studies on alcohol dehydrogenase, malic enzyme, peroxidase, acid phosphase, and aminopeptidase isoenzymes were carried out on several groups of rice varieties and their mutant lines. The first groups consisted of Atomita I, Pelita I/1, A227/5, Mudgo, TN-1, and IR-26. The second group was Cisadane variety and its five mutants, namely OBS 18, OBS 208, OBS 297, OBS 306, and OBS 330. The third group was mutants line 627-10-3 and its mutants, namely 1063, 1066, 1067, 1076, and 1090. Isoenzymes extracts of the rice leaves were fractionated using polyacrylamide gel disc electrophoresis. The pattern of acid phosphate isoenzyme shows the specific character of rice mutants susceptible to brown plant hopper biotype 1. The gene(s) controlling malic enzyme in Cisadane's mutants is (are) estimated more resistant toward gamma irradiation than gene(s) responsible for controlling the other enzymes. Generally, the isoenzymes zymograms show that gene(s) controlling the mutants enzyme have undergone mutation. This case is shown by the changes of Rm value, as well as the amount and intensity of mutants bands. (authors). 7 refs., 7 figs

  12. Agronomic performance of old soybean variety 'Altona' derived mutants

    International Nuclear Information System (INIS)

    Hodosne, K.G.; Heszky, L.E.

    2001-01-01

    An induced mutation program has been initiated at the Department of Genetics and Plant Breeding to develop early maturing cultivars with good yielding capacity. Some new mutants have been produced by irradiation of variety Altona with 60 Co gamma rays. Ten years of breeding resulted in two new mutant varieties named 'Noventa' and 'Gate 511'. The present study deals with agronomic performance of these mutants. Registered soybean varieties Altona and 'McCall' as well as Altona derived mutants (Gate 511 and Noventa) have been compared

  13. Seed protein and nitrogen fixation in chickpea mutant variety Hyprosola

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, H E; Gibson, A H; Oram, R N [CSIRO, Division of Plant Industry, Canberra ACT (Australia); Shaikh, M A.Q. [Bangladesh Institute of Nuclear Agriculture, Mymensingh (Bangladesh)

    1989-01-01

    Full text: 'Hyprosola' is a high yielding, high protein mutant cultivar obtained after gamma irradiation from the variety 'Faridpur-1'. The mutant yields 45 % more protein per unit area. The essential amino acid index is unchanged. It is likely that the high nutritional value in 'Hyprosola' seed protein arises from an increase in the albumin:globulin ratio. Nitrogen fixation rates of the mutant during the first 7 weeks of growth were found to be similar to 'Faridpur-1'. Under field conditions, the mutant may be able to nodulate more rapidly and more extensively than the parent variety. (author)

  14. Morphological and physiological investigations on mutants of Fusarium monoliforme IM

    International Nuclear Information System (INIS)

    Gancheva, V.

    1996-01-01

    High-producing mutants of Fusarium moniliforme IM are obtained as a result of gamma irradiation. The cultural characteristics of mutant strains 3284, 3211 and 76 following incubation of the producers for 14 days on potato-glucose agar are described. The colour of the aerial and substrate mycelium and the ability of the mutant strains to form conidiae and pigments are discussed in detail. The differences in the ability of mutants to assimilate different carbon and nitrogen sources are of specific importance for modelling nutrient media for submerged cultivation of F. moniliforme. 2 tabs., 2 figs. 7 refs

  15. Ascertainment of the effect of differential growth rates of mutants on observed mutant frequencies in X-irradiated mammalian cells

    International Nuclear Information System (INIS)

    Knaap, A.G.A.C.; Simons, J.W.I.M.

    1983-01-01

    As it is not known to what extent differential growth rates of induced mutants lead to over- and under-representation of mutants in treated populations and thereby affect the determination of mutant frequencies, the mutation induction in X-irradiated L5178Y mouse lymphoma cells was determined via two methods. The first method involves the standard protocol which may suffer from the effect of differential growth rates, while the second method is based upon the fluctuation test in which the differential growth rates can be actually measured. It appeared that the standard protocol led to a mutant frequency that was similar to the mutant frequency determined in the fluctuation test. Therefore, the standard protocol appears to lead to only a minor under-estimation if any. Substantial heterogeneity in growth rates of induced mutants was observed, but the mutants with a selective advantage appear largely to compensate for the mutants that are lost because of selective disadvantage. It was calculated that the chance for isolating the same mutant twice from a treated population had been increased 2.2-fold because of the observed differential growth rates. (orig./AJ)

  16. Applications of Protein Thermodynamic Database for Understanding Protein Mutant Stability and Designing Stable Mutants.

    Science.gov (United States)

    Gromiha, M Michael; Anoosha, P; Huang, Liang-Tsung

    2016-01-01

    Protein stability is the free energy difference between unfolded and folded states of a protein, which lies in the range of 5-25 kcal/mol. Experimentally, protein stability is measured with circular dichroism, differential scanning calorimetry, and fluorescence spectroscopy using thermal and denaturant denaturation methods. These experimental data have been accumulated in the form of a database, ProTherm, thermodynamic database for proteins and mutants. It also contains sequence and structure information of a protein, experimental methods and conditions, and literature information. Different features such as search, display, and sorting options and visualization tools have been incorporated in the database. ProTherm is a valuable resource for understanding/predicting the stability of proteins and it can be accessed at http://www.abren.net/protherm/ . ProTherm has been effectively used to examine the relationship among thermodynamics, structure, and function of proteins. We describe the recent progress on the development of methods for understanding/predicting protein stability, such as (1) general trends on mutational effects on stability, (2) relationship between the stability of protein mutants and amino acid properties, (3) applications of protein three-dimensional structures for predicting their stability upon point mutations, (4) prediction of protein stability upon single mutations from amino acid sequence, and (5) prediction methods for addressing double mutants. A list of online resources for predicting has also been provided.

  17. Mutants dissecting development and behaviour in drosophila

    International Nuclear Information System (INIS)

    Joshi, Adita; Chandrashekaran, Shanti; Sharma, R.P.

    2005-01-01

    We have traced in this paper the progress in Drosophila genetics research from the 1960s, at the IARI, spearheaded by the visionary insight of M. S. Swaminathan. The work started with the study of indirect effect of radiation and the synergistic interaction of physical and chemical mutagens on chromosomal and genetic changes. This paved the way for the study of single gene mutants in dissecting developmental and behavioural processes. New genes discovered by us have been shown to encode conserved cell signalling molecules controlling developmental and behavioural pathways. With the complete sequencing of the Drosophila genome, in the year 2000, mounting evidence for the homology between Drosophila and human genes controlling genetic disorders became available. This has led to the fly becoming an indispensable tool for studying human diseases as well as a model to test for drugs and pharmaceuticals against human diseases and complex behavioural processes. For example wingless in Drosophila belongs to the conserved Wnt gene family and aberrant WNT signalling is linked to a range of human diseases, most notably cancer. Inhibition as well as activation of WNT signalling form the basis of an effective therapy for some cancers as well as several other clinical conditions. Recent experiments have shown that WNTs might also normally participate in self-renewal, proliferation or differentiation of stem cells and altering WNT signalling might be beneficial to the use of stem cells for therapeutic means. Likewise, the stambhA mutant of Drosophila which was discovered for its temperature-dependent paralytic behaviour is the fly homologue of Phospholipase Cβ. Phospholipase C mediated G protein signalling plays a central role in vital processes controlling epilepsy, vision, taste, and olfaction in animals. Proteins of the G-signalling pathway are of intense research interest since many human diseases involve defects in G-protein signalling pathways. In fact, approximately 50

  18. Histological and Molecular Characterization of Grape Early Ripening Bud Mutant

    Directory of Open Access Journals (Sweden)

    Da-Long Guo

    2016-01-01

    Full Text Available An early ripening bud mutant was analyzed based on the histological, SSR, and methylation-sensitive amplified polymorphism (MSAP analysis and a layer-specific approach was used to investigate the differentiation between the bud mutant and its parent. The results showed that the thickness of leaf spongy tissue of mutant (MT is larger than that of wild type (WT and the differences are significant. The mean size of cell layer L2 was increased in the mutant and the difference is significant. The genetic background of bud mutant revealed by SSR analysis is highly uniform to its parent; just the variations from VVS2 SSR marker were detected in MT. The total methylation ratio of MT is lower than that of the corresponding WT. The outside methylation ratio in MT is much less than that in WT; the average inner methylation ratio in MT is larger than that in WT. The early ripening bud mutant has certain proportion demethylation in cell layer L2. All the results suggested that cell layer L2 of the early ripening bud mutant has changed from the WT. This study provided the basis for a better understanding of the characteristic features of the early ripening bud mutant in grape.

  19. Gamma-ray induced mutants in castor (Ricinus communis L.)

    International Nuclear Information System (INIS)

    Janila, P.; Ashok Kumar, A.; Rajashekar Reddy, N.; Hemalatha, V.

    2007-01-01

    We report isolation of three recessive mutants in castor using dry seed irradiation with gamma rays. The crinkled leaf mutant (crf) was identified in K-55-112 M2 family and leafy mutant (lea) in H-55-577 M2 family; both are recessive lethal and thus maintained as heterozygotes. The cri mutant has highly wrinkled leaves resembling finger millet head and failed to enter reproductive phase, consequently did not produce seeds. The number of leaf lobes is reduced in lea mutant and though it produced spikes, the male and female flowers are converted to leafy appendages. The third mutant, fused (Ius) stem identified in H-55-617 M2 family is a recessive mutant. The branches of which are fused at the base and though each branch terminates in to monoceous spike like normal plant, the spike is highly condensed. The three mutants under report are valuable genetic stocks for development of linkage maps in castor, which is at infancy. (author)

  20. Development of Database Software with Plant Mutant Resources

    International Nuclear Information System (INIS)

    Namgoong, Won; Lee, M. J.; Kim, J. D.; Ma, N. K.

    2007-03-01

    In this research, mutants induced by nuclear radiation are developed information computerised system. The status and progress on the collection, identification and utilization of mutants in Korea are introduced. And it was produced home page, manual, test record, construction of system

  1. Clear Plaque Mutants of Lactococcal Phage TP901-1

    DEFF Research Database (Denmark)

    Kot, Witold; Kilstrup, Mogens; Vogensen, Finn K.

    2016-01-01

    We report a method for obtaining turbid plaques of the lactococcal bacteriophage TP901-1 and its derivative TP901-BC1034. We have further used the method to isolate clear plaque mutants of this phage. Analysis of 8 such mutants that were unable to lysogenize the host included whole genome...

  2. Isolation and characterization of stable mutants of Streptomyces

    Indian Academy of Sciences (India)

    Daunorubicin and its derivative doxorubicin are antitumour anthracycline antibiotics produced by Streptomyces peucetius. In this study we report isolation of stable mutants of S. peucetius blocked in different steps of the daunorubicin biosynthesis pathway. Mutants were screened on the basis of colony colour since producer ...

  3. Photosynthetic characterization of a rolled leaf mutant of rice ( Oryza ...

    African Journals Online (AJOL)

    A new rolling leaf rice mutant was identified which showed an apparently straighter longitudinal shape normal transverse rolling characters at all developing stages. The chlorophyll contents per fresh weight of this mutant leaves were lower than those of wild-type. The electron transfer rate (ETR) and photochemical ...

  4. Mutant strain of C. acetobutylicum and process for making butanol

    Science.gov (United States)

    Jain, Mahendra K.; Beacom, Daniel; Datta, Rathin

    1993-01-01

    A biologically pure asporogenic mutant of Clostridium acetobutylicum is produced by growing sporogenic C. acetobutylicum ATCC 4259 and treating the parent strain with ethane methane sulfonate. The mutant which as been designated C. acetobutylicum ATCC 55025 is useful in an improved ABE fermentation process, and produces high concentrations of butanol and total solvents.

  5. Sorghum Brown Midrib Mutants, Tools to Improve Biomass for Biofuels

    Science.gov (United States)

    To improve sorghum for cellulosic bioenergy uses, brown midrib mutants are being investigated for their ability to increase the conversion efficiency of biomass. brown midrib 6 and 12 (bmr6 and 12) mutants affect monolignol biosynthesis resulting in reduced lignin content and altered lignin composi...

  6. Isozyme patterns of powdery mildew resistant wheat mutants

    International Nuclear Information System (INIS)

    Xia Wengau; Li Zhengkui; Wang Kefeng

    1989-01-01

    Full Text: Wheat mutants induced by gamma irradiation and showing improved resistance to powdery mildew were analysed for isozymes. The peroxidase band 3A could be related to the disease reaction. The band 3A is absent in resistant mutants, the higher the activity of band 3A the greater the susceptibility. (author)

  7. Strain improvement in dye decolourising mutants of Mucor mucedo ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... M. mucedo {MMM1-U.V. irradiated mutant and MMM2-EMS (ethyl methyl sulfonate) treated ... tions were induced and two positive mutants (MMM1, .... yeast biofilter for the treatment of a Nigerian fertilizer plant effluent. World J.

  8. Chinese hamster ovary cell mutants defective in heparan sulfate biosynthesis

    International Nuclear Information System (INIS)

    Bame, K.J.; Kiser, C.S.; Esko, J.D.

    1987-01-01

    The authors have isolated Chinese hamster ovary cell mutants defective in proteoglycan synthesis by radiographic screening for cells unable to incorporate 35 SO 4 into acid-precipitable material. Some mutants did not incorporate 35 SO 4 into acid-precipitable material, whereas others incorporated about 3-fold less radioactivity. HPLC anion exchange chromatographic analysis of radiolabelled glycosaminoglycans isolated from these mutants revealed many are defective in heparan sulfate biosynthesis. Mutants 803 and 677 do not synthesize heparan sulfate, although they produce chondroitin sulfate: strain 803 makes chondroitin sulfate normally, whereas 677 overaccumulates chondroitin sulfate by a factor of three. These mutants fall into the same complementation group, suggesting that the mutations are allelic. A second group of heparan sulfate biosynthetic mutants, consisting of cell lines 625, 668 and 679, produce undersulfated heparan sulfate and normal chondroitin sulfate. Treatment of the chains with nitrous acid should determine the position of the sulfate groups along the chain. These mutants may define a complementation group that is defective in the enzymes which modify the heparan sulfate chain. To increase the authors repertoire of heparan sulfate mutants, they are presently developing an in situ enzyme assay to screen colonies replica plated on filter discs for sulfotransferase defects

  9. Screening of in vitro derived mutants of banana against nematodes ...

    African Journals Online (AJOL)

    The rest of the mutants namely Ro Im V4 6-1-2 and Si Im V4 6-2-5 were found to be susceptible to nematodes. The resistant and moderately resistant mutants of banana could be further used in breeding programmes as well as being recognized as potential cultivars of commerce. Key words: Banana, nematode, resistance, ...

  10. Induction and characterization of Arabidopsis mutants by Ion beam

    International Nuclear Information System (INIS)

    Yoon, Y. H.; Choi, J. D.; Park, J. Y.; Lee, J. R.; Sohn, H. S.

    2008-03-01

    This study was conducted to search the proper conditions and times for irradiating proton beam to seeds generally used for induction of mutant. Arabidopsis as model plants has good characters that is a short generation time, producing a lot of seeds, sequenced genome, developed maker. This points were the best materials for plant breeding for this study. The data of inducing mutants of Arabidopsis is used to be applicate to crops have more longer generation that is the final goals of this study. The goals of this project were to inducing and characterizing arabidopsis mutants by the proton ion beam and γ-ray. As well as, the purpose of this study was securing more than 10 lines of arabidopsis mutants in this project and also to know the changed DNA structure of the mutants using the basic data for applying to the more study

  11. Phage Pl mutants with altered transducing abilities for Escherichia coli

    International Nuclear Information System (INIS)

    Wall, J.D.; Harriman, P.D.

    1974-01-01

    A search was made for mutants of the coliphage P1 with altered transducing frequencies. A method was developed for the rapid assay of transducing frequencies in single plaques using prophage lambda as the transduced bacterial marker. This procedure selects for mutants altered in their ability to package host DNA. Mutants with 5 to 10 times higher or 10 to 20 times lower frequencies than those of wild-type P1 were found. Not only are the markers used for the detection of the mutants affected, but all other markers are similarly affected (not always to the same extent). One of the high transducing frequency mutants is a suppressible amber, indicating that loss of a function increases P1's ability to package host DNA preferentially. (U.S.)

  12. Spectrum of mutant characters utilized in developing improved cultivars

    International Nuclear Information System (INIS)

    Donini, B.; Kawai, T.; Micke, A.

    1984-01-01

    Although about 500 cultivars are known to have been developed by using induced mutations, the range of mutant traits seems to be rather narrow. Mutant traits have mostly been used that can be detected visually on an individual plant basis. However, in the background of such mutants other valuable mutations have been found in later generations. In cross-breeding with mutants valuable characteristics occurred, which could not be predicted from the phenotypes of the parents. It is concluded that improved attributes in the released mutant varieties do not comprise the entire genetic variation that could derive from mutagenesis. Current selection techniques are inadequate to exploit the full potential of mutagenesis for plant breeding. (author)

  13. Poliovirus Mutants Resistant to Neutralization with Soluble Cell Receptors

    Science.gov (United States)

    Kaplan, Gerardo; Peters, David; Racaniello, Vincent R.

    1990-12-01

    Poliovirus mutants resistant to neutralization with soluble cellular receptor were isolated. Replication of soluble receptor-resistant (srr) mutants was blocked by a monoclonal antibody directed against the HeLa cell receptor for poliovirus, indicating that the mutants use this receptor to enter cells. The srr mutants showed reduced binding to HeLa cells and cell membranes. However, the reduced binding phenotype did not have a major impact on viral replication, as judged by plaque size and one-step growth curves. These results suggest that the use of soluble receptors as antiviral agents could lead to the selection of neutralization-resistant mutants that are able to bind cell surface receptors, replicate, and cause disease.

  14. The agronomic characters of a high protein rice mutant

    International Nuclear Information System (INIS)

    Harn, C.; Won, J.L.; Choi, K.T.

    1975-01-01

    Mutant lines (M 5 -M 9 ) of macro-phenotypic traits from several varieties were screened for the protein content. Mutant 398 (M 9 ) is one of the high protein mutants selected from Hokwang. Three years' tests revealed that it has a high protein line under any condition of cultivation. Except for early maturity and short culmness, other agronomic and yield characters were similar to the original variety. There was no difference between the mutant 398 and its mother variety in grain shape and weight, and also the size and protein content of the embryo. The high protein content of the mutant is attributable to the increase of protein in the endosperm. About 150 normal-looking or a few days-earlier-maturing selections were made from Jinheung variety in the M 3 and screened for protein. Promising lines in terms of the plant type, yield and protein were obtained. (author)

  15. Mildew resistant and less lodging wheat mutants induced in Iran

    International Nuclear Information System (INIS)

    Naghedi-Ahmadi, I.

    1989-01-01

    ''Tabassi'' is a lodging and mildew susceptible cultivar. To induce mutations, seeds were gamma irradiated (50 to 150 Gy) in 1982 and selection for lodging resistance was carried out in M 2 . During field experiments with the mutant lines in 1985/86 there has been a heavy mildew epidemic under which mutant 63-5-I (derived from 50 Gy treatment) exhibited considerable resistance and as a consequence, higher yield. The control was 100% infected, the mutant only 40%. The mutant yielded 31% more grain, 7.5% less straw and 4.5% more protein than the control. Lodging of 63-5-I was only 60% in an experiment under rainfed conditions in the same season, resulting in a relative yield increase of about 11%. In 1986/87 there was no mildew epidemic and the mutant yielded the same as ''Tabassi''

  16. Characteristics of mutant lines of sweet potato flour

    International Nuclear Information System (INIS)

    Aryanti

    2012-01-01

    Research on mutation induction of sweet potato Sari variety has been conducted. Flour mutant lines were obtained from selection of M1V5 tubers irradiated by gamma rays at the dose of 10 Gy. Flour was made by peeling of tubers, then dried, blended and sieved. The quality test of flour have been done by measuring degree of whiteness, proximate, amylose contents, water content, soluble water, swelling power, and flour characteristics. The result of this work showed that flour of C6.26.13 mutant line had higher protein content than the parent plant with concentration of 3.62 % and its amylose content was also higher than the other mutant lines. The soluble water value of mutant lines were significant different compared to the parent plant from 1.82 to 2.25 % and swelling power from 4.28 to 5.55 %. The flour granule of the mutant line was different compared to the parent plant. (author)

  17. Photosynthetic and nitrogen fixation capability in several soybean mutant lines

    International Nuclear Information System (INIS)

    Gandanegara, S.; Hendratno, K.

    1987-01-01

    Photosynthetic and nitrogen fixation capability in several soybean mutant lines. A greenhouse experiment has been carried out to study photosynthetic and nitrogen fixation capability of five mutant lines and two soybean varieties. An amount of 330 uCi of 14 CO 2 was fed to the plants including of the non-fixing reference crop (Chippewa non-nodulating isoline). Nitrogen fixation measurements was carried out using 15 N isotope dilution technique according to A-value concept. Results showed that beside variety/mutant lines, plant growth also has important role in photosynthetic and N fixing capability. Better growth and a higher photosynthetic capability in Orba, mutant lines nos. 63 and 65 resulted in a greater amount of N 2 fixed (mg N/plant) than other mutant lines. (author). 12 refs.; 5 figs

  18. Induction and characterization of Arabidopsis mutants by Ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Y. H.; Choi, J. D.; Park, J. Y.; Lee, J. R.; Sohn, H. S. [Gyeongbuk Institute for Bio Industry, Andong (Korea, Republic of)

    2008-03-15

    This study was conducted to search the proper conditions and times for irradiating proton beam to seeds generally used for induction of mutant. Arabidopsis as model plants has good characters that is a short generation time, producing a lot of seeds, sequenced genome, developed maker. This points were the best materials for plant breeding for this study. The data of inducing mutants of Arabidopsis is used to be applicate to crops have more longer generation that is the final goals of this study. The goals of this project were to inducing and characterizing arabidopsis mutants by the proton ion beam and {gamma}-ray. As well as, the purpose of this study was securing more than 10 lines of arabidopsis mutants in this project and also to know the changed DNA structure of the mutants using the basic data for applying to the more study

  19. Study on growth condition of Trichoderma mutants

    International Nuclear Information System (INIS)

    Chen Jian'ai; Xiao Min; Wang Weiming; Chen Weijing; Sun Yongtang

    2002-01-01

    Some Trichoderma mutants were cultured under different conditions 4 strains, T5, T0803, T1010, T1003 were selected with different mediums and every medium was mixed with fungicide of 40 ppm. The fungicides were procymidone + chlorothalonil, maneb and phosethyl-Al. The pH of medium were 5, 6, 7 and 8, respectively. The growing temperatures were 15, 20, 25 and 30 degree C, respectively. After the hypha growing for some days under natural high temperature, they were put in low temperature for producing spores. The growing times for these hypha were 3,4,5 and 6 days, respectively. All dates were analyzed on statistics with the orthogonal array and ranges (R) were different with different factor and levels (R = 40.4, 42.4, 48.0, 62.8, 107.0). The results showed that the strain was the most influent condition (R = 107.0) and the changed temperature time from high to low was the least influent condition (R = 40.4). Each factor variance was significant and A 3 b 4 C 2 D 1 E 3 was the optimum combined condition, under which T1010 grew more quickly and produced the most spores

  20. Assessment and application of oats mutant forms

    Energy Technology Data Exchange (ETDEWEB)

    Velikovsky, V [Vyzkumny a Slechtitelsky Ustav Obilnarsky, Kromeriz (Czechoslovakia)

    1978-04-01

    Five oat varieties were studied for the effect of X-rays on the degree of survival, on the occurrence rate of mutations, and on the possibility of obtaining improved forms for further breeding work. Oats were treated with doses of 20,000 and 40,000 R and the latter dose was found to be highly lethal. For this reason, further studies were performed with doses of 15,000 and 25,000 R. The 'Diadem' variety (CSSR) showed the highest sensitivity to irradiation. The varieties 'Tiger' (West Germany) and 'Diane' (Belgium) showed medium susceptibility and the 'Permit' and 'Pollux' varieties (both W. Germany) were the least sensitive. In selection oriented mainly to stalk shortening and to higher resistance to lodging, the greatest number of useful macromutations was obtained from the 'Permit' variety after exposure of dry seeds to a dose of 20,000 R. The most promising mutant forms obtained in this variety were sent to some breeding stations of the Plant-Breeding and Seed-Production Enterprise Oseva for further breeding use.

  1. Radiation induced mutants in cassava (Manihot esculenta Crantz)

    International Nuclear Information System (INIS)

    Nayar, G.G.; Rajendran, P.G.

    1987-01-01

    Full text: Stem cuttings and true seeds of three promising cultivars of cassava were exposed respectively to 1 to 5 kR and 10 to 50 kR acute gamma rays from a 60 Co source. Treatments of stem cuttings beyond 5 kR and seeds beyond 50 kR were lethal. One mutant each in the cultivars M4, H-165 and H-2304 was obtained from the stem irradiated populations. Another mutant was found in the seed irradiated progeny of H-2304. The mutant of M4 is characterised by light green (chlorina) leaves. The mutant of H-165 shows significantly shorter petiole (22,5 against 35.2 cm) and narrow leaf lobes, while the H-2304 mutant shows speckled leaves, branching and early flowering. The mutant found in the seed irradiated progeny of H-2304 is having yellow tuber flesh indicating the presence of carotene. The mutants may be useful in studies related to basic information as well as in practical breeding. The chlorina mutant in M4 showed slow growth and high HCN content in leaves. Late branching may be a useful trait in the traditionally non-branching clones of cassava to maintain the desirable leaf area index during high leaf fall period. Early flowering could be useful in a recombinant breeding programme. The tuber yield of the short petiole mutant in H-165 increased by 20% - 25% through closer planting. The narrow leaf lobes of this mutant permit better light penetration to lower leaves. (author)

  2. Human liver cell trafficking mutants: characterization and whole exome sequencing.

    Directory of Open Access Journals (Sweden)

    Fei Yuan

    Full Text Available The HuH7 liver cell mutant Trf1 is defective in membrane trafficking and is complemented by the casein kinase 2α subunit CK2α''. Here we identify characteristic morphologies, trafficking and mutational changes in six additional HuH7 mutants Trf2-Trf7. Trf1 cells were previously shown to be severely defective in gap junction functions. Using a Lucifer yellow transfer assay, remarkable attenuation of gap junction communication was revealed in each of the mutants Trf2-Trf7. Electron microscopy and light microscopy of thiamine pyrophosphatase showed that several mutants exhibited fragmented Golgi apparatus cisternae compared to parental HuH7 cells. Intracellular trafficking was investigated using assays of transferrin endocytosis and recycling and VSV G secretion. Surface binding of transferrin was reduced in all six Trf2-Trf7 mutants, which generally correlated with the degree of reduced expression of the transferrin receptor at the cell surface. The mutants displayed the same transferrin influx rates as HuH7, and for efflux rate, only Trf6 differed, having a slower transferrin efflux rate than HuH7. The kinetics of VSV G transport along the exocytic pathway were altered in Trf2 and Trf5 mutants. Genetic changes unique to particular Trf mutants were identified by exome sequencing, and one was investigated in depth. The novel mutation Ile34Phe in the GTPase RAB22A was identified in Trf4. RNA interference knockdown of RAB22A or overexpression of RAB22AI34F in HuH7 cells caused phenotypic changes characteristic of the Trf4 mutant. In addition, the Ile34Phe mutation reduced both guanine nucleotide binding and hydrolysis activities of RAB22A. Thus, the RAB22A Ile34Phe mutation appears to contribute to the Trf4 mutant phenotype.

  3. Homologous series of induced early mutants in indican rice. Pt.1. The production of homologous series of early mutants

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    1999-01-01

    The percentage of homologous series of early mutants induced from the same Indican rice variety were almost the same (1.37%∼1.64%) in 1983∼1993, but the ones from the different eco-typical varieties were different. The early variety was 0.73%, the mid variety was 1.51%, and the late variety was 1.97%. The percentage of homologous series of early mutants from the varieties with the same pedigree and relationship were similar, but the one from the cog nation were lower than those from distant varieties. There are basic laws and characters in the homologous series of early mutants: 1. The inhibited phenotype is the basic of the homologous series of early mutants; 2. The production of the homologous series of early mutants is closely related with the growing period of the parent; 3. The parallel mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing; 4. The occurrence of the homologous series of early mutants is in a state of imbalance. According to the law of parallel variability, the production of homologous series of early mutants can be predicted as long as the parents' classification of plant, pedigree and ecological type are identified. Therefore, the early breeding can be guided by the law of homologous series of early mutants

  4. Genetic studies on dwarf triticale mutants

    International Nuclear Information System (INIS)

    Nalepa, S.

    1984-01-01

    The parents, F 1 , F 2 and backcrosses derived from triticale dwarf mutants and tall cultivars were studied during the 1979-80 crop season. Data was taken on individual plants to estimate dwarf inheritance, gene action and interrelationships of grain yield and selected yield related traits. The direct and indirect effects of grain yield per spike on other grain yield components were also studied. Results indicate that dwarfing is controlled by two, partially dominant, genes. Additional crosses involving other hexaploid triticale lines revealed the inheritance of other characters. The results in F 2 show that glossy plant, waxy covering of the neck and hairy neck are dominant, while short straw is recessive. Waxy covering on the spike seems to be controlled by two genes with additive action. Observation of F 2 progenies indicates that a gene for waxy neck covering Wx and hairy neck Hp might be located on the same chromosome at a distance of about 19 units. Plant height showed a positive phenotypic correlation with grain yield and 1,000 kernel weight. Non-significant correlations were found between plant height and number of grains per spike, harvest index and spikelet fertility. Path coefficient analyses at the phenotypic level indicated that the direct effects of grain number on grain yield were large while the direct effects of 1,000 kernel weight were relatively small. The results of this study indicate that selection for high kernel number is the most important factor in a breeding programme for increasing grain yield in some dwarf triticale. It was found that epistasis is not involved in the inheritance of harvest index. Additive, dominance and additive x dominance epistasis were important for grain yield per spike. A duplicate type of epistasis was found for 1,000 kernel weight and number of grains per spikelet. (author)

  5. Induced mutant for male sterility in niger

    International Nuclear Information System (INIS)

    Sujatha, M.

    2001-01-01

    Full text: Niger (Guizotia abyssinica Cass.), an important oilseed crop of the family Compositae is highly cross-pollinated due to the twin mechanisms of protandry and incompatibility. Studies revealed the functional nature of protandry and the breakdown of incompatibility with alteration in temperature. It has very small flowers (disc florets) arranged in a capitulum that open on 3-4 consecutive days which pose problems in emasculation for cross-breeding. To induce mutations, seeds of variety 'IGP-76' were irradiated with γ-rays 200 to 1000 Gy. All seeds of M 1 plants were sown separately in individual plant-to progeny rows. The results of screening of M 2 segregating material indicated that γ-ray treatment was effective in induction of male sterility. Frequency of visible mutations were higher in sibbed progeny as compared to open pollinated population and male sterile plants were observed only in sibbed population (1000 Gy). Male sterile plants could easily be identified at the flowering stage by their altered floral morphology (disc florets transformed into ligulate ray florets) and complete absence or presence of a rudimentary anther column. Seeds were collected following sib-mating with the fertile counterparts. Progeny segregated in a ration of 3 normal : 1 male sterile. Further work on the mechanism of sterility, maintenance and linkage relationships with associated characters is under progress. This is the first report of induction of male sterility in niger through the use of physical mutagens. The availability of this mutant will be of great value for exploitation of heterosis on commercial basis. (author)

  6. Mapping pathological phenotypes in Reelin mutant mice

    Directory of Open Access Journals (Sweden)

    Caterina eMichetti

    2014-09-01

    Full Text Available Autism Spectrum Disorders (ASD are neurodevelopmental disorders with multifactorial origin characterized by social communication and behavioural perseveration deficits. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we investigated the behavioural, neurochemical and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in ultrasonic vocal repertoire and a general delay in motor development in reeler pups. We now report that adult male heterozygous reeler mice did not show social behaviour and communication deficits during male-female social interactions. Wildtype and heterozygous mice also showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection only heterozygous mice showed an over response to stress. At the end of the behavioural studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in heterozygous mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD

  7. Ethanol production using nuclear petite yeast mutants

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, A.; Oliver, S.G. [Department of Biomolecular Sciences, UMIST, Manchester (United Kingdom)

    1998-12-31

    Two respiratory-deficient nuclear petites, FY23{Delta}pet191 and FY23{Delta}cox5a, of the yeast Saccharomyces cerevisiae were generated using polymerase-chain-reaction-mediated gene disruption, and their respective ethanol tolerance and productivity assessed and compared to those of the parental grande, FY23WT, and a mitochondrial petite, FY23{rho}{sup 0}. Batch culture studies demonstrated that the parental strain was the most tolerant to exogenously added ethanol with an inhibition constant. K{sub i}, of 2.3% (w/v) and a specific rate of ethanol production, q{sub p}, of 0.90 g ethanol g dry cells{sup -1} h{sup -1}. FY23{rho}{sup 0} was the most sensitive to ethanol, exhibiting a K{sub i} of 1.71% (w/v) and q{sub p} of 0.87 g ethanol g dry cells{sup -1} h{sup -1}. Analyses of the ethanol tolerance of the nuclear petites demonstrate that functional mitochondria are essential for maintaining tolerance to the toxin with the 100% respiratory-deficient nuclear petite, FY23{Delta}pet191, having a K{sub i} of 2.14% (w/v) and the 85% respiratory-deficient FY23{Delta}cox5a, having a K{sub i} of 1.94% (w/v). The retention of ethanol tolerance in the nuclear petites as compared to that of FY23{rho}{sup 0} is mirrored by the ethanol productivities of these nuclear mutants, being respectively 43% and 30% higher than that of the respiratory-sufficient parent strain. This demonstrates that, because of their respiratory deficiency, the nuclear petites are not subject of the Pasteur effect and so exhibit higher rates of fermentation. (orig.)

  8. Circulation of Pneumocystis dihydropteroate synthase mutants in France.

    Science.gov (United States)

    Le Gal, Solène; Damiani, Céline; Perrot, Maëla; Rouillé, Amélie; Virmaux, Michèle; Quinio, Dorothée; Moalic, Elodie; Saliou, Philippe; Berthou, Christian; Le Meur, Yann; Totet, Anne; Nevez, Gilles

    2012-10-01

    Data on the prevalence of Pneumocystis jirovecii (P. jirovecii) dihydropteroate synthase (DHPS) mutants in France are still limited. In this study, mutant prevalence in the Brest region (western France) was determined. Archival pulmonary specimens from 85 patients infected with P. jirovecii and admitted to our institution (University Hospital, Brest) from October 2007 to February 2010 were retrospectively typed at the DHPS locus using a polymerase chain reaction-restriction fragment length polymorphism assay. Type identification was successful in 66 of 85 patients. Sixty-four patients were infected with a wild type, whereas mutants were found in 2 patients (2/66, 3%). Medical chart analysis revealed that these 2 patients usually lived in Paris. Another patient usually lived on the French Riviera, whereas 63 patients were from the city of Brest. Thus, the corrected prevalence of mutants in patients who effectively lived in our geographic area was 0% (0/63). Taking into account that i) Paris is characterized by a high prevalence of mutants from 18.5% to 40%, ii) infection diagnoses were performed in the 2 Parisians during their vacation Paris to Brest through infected vacationers. The study shows that the usual city of patient residence, rather than the city of infection diagnosis, is a predictor of mutants and that P. jirovecii infections involving mutants do not represent a public health issue in western France. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Cytogenetic characteristics of soft wheat mutants under x-irradiation

    International Nuclear Information System (INIS)

    Shakaryan, Zh.O.; Avakyan, V.A.; Amirbekyan, V.A.

    1981-01-01

    Radiosensitivity of induced mutants of soft wheat is studied by criteria of frequency and character of changes in 1 and 2 divisions of meiosis. Two constant induced mutant forms of soft wheat were investigated. Mutant lines of squareheads with red ear (re) and erectoids 37/1 were obtained by X-ray irradiating hydride seeds F 1 of hybride combination of Alty-Agach Awnless 1. Seeds of mutants and initial kinds were exposed to X-rays at a dose of 10 kR. A conclusion may be drawn on the basis of studying the meiosis process in mutants and initial kinds of soft wheat on X-ray radiation that the mutants are more radiosensitive. This testifies to that that the induced mutants of soft wheat represent new genotypes in comparison with the initial kinds and differ from the latter not only in morphological characters but in the reaction norm with respect to external medium factors, i.e. the limit of possible changeability of the genotype has been extended [ru

  10. Methods of producing protoporphyrin IX and bacterial mutants therefor

    Science.gov (United States)

    Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

    2016-03-01

    The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

  11. Genetics of Ustilago violacea. I. Carotenoid mutants and carotenogenesis

    International Nuclear Information System (INIS)

    Garber, E.D.; Baird, M.L.; Chapman, D.J.

    1975-01-01

    Wild-type strains of Ustilago violacea produce pink colonies on laboratory medium and yield white, orange, pumpkin, and yellow colonies after uv mutagenesis. The wild-type strains contain neurosporene and lycopene; one orange mutant, γ-carotene; and one yellow mutant, β-carotene. One white mutant had no detectable carotenoids. Diploid colonies heterozygous for wild type and orange, pumpkin, yellow, or white are phenotypically wild type. Diploid colonies heterozygous for yellow and orange are also phenotypically wild type. Diploid colonies heterozygous for white and orange; white and yellow; and white, yellow, and orange are phenotypically light orange, light yellow, and orange-yellow, respectively. The white mutants give a circular complementation map; the color mutants fit a linear complementation map. We propose a multienzyme of four identical dehydrogenases and one or two identical cyclases for carotenogenesis in this species. The white and color mutants represent structural mutations altering the conformation of the dehydrogenase or cyclase, respectively. Furthermore, cyclases may or may not aggregate in association with the dehydrogenase aggregate to form the multienzyme aggregate responsible for the color mutants

  12. Promising semi-dwarf mutant in wheat variety K68

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, D [Banaras Hindu Univ. (India). Dept. of Genetics and Plant Breeding

    1977-04-01

    A semi-dwarf mutant (HUW-SDf 1) was induced from common wheat Var. K68 through the exposure of /sup 60/Co ..gamma..-rays at 15 kR. This mutant along with other induced mutants and control was assessed for yield components, yield and grain quality (M/sub 4/ generation); internode length reduction pattern and the yielding ability at three levels of nitrogen (M/sub 5/ generation). The mutant was significantly shorter in height and almost equal in tillers per plant and grains per spike to K68. However, it showed marked reduction in spike length and spikelets per spike. On the other hand, it possessed significantly higher (50.04 g) 1000-grain weight against control (41.15 g). The mutant gave 56.0% higher yield than the control. Grain quality studies indicated that the mutant possessed significantly higher (14.15%) total protein than K68. It was equally as good as K68 in lysine content. Pelshenke value (62.5 min) of the mutant indicated medium hard nature of gluten as compared to hard nature (198.0) of the control. The mutant showed 24.0% reduction in total culm length compared to K68. Reduction occurred due to maximum and almost equal reduction in 5th and 4th internodes (ca 34.0%) followed by 3rd, 2nd and 1st. The mutant showed similar yield and yield response to increasing nitrogen levels (80 to 160 kg per ha.) as for current commercial semi-dwarf varieties.

  13. Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Anders Bøgh; Raventos, D.; Mundy, John Williams

    2002-01-01

    as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition...... activity was also induced by the protein kinase inhibitor staurosporine and antagonized by the protein phosphatase inhibitor okadaic acid. FLUC bio-imaging, RNA gel-blot analysis and progeny analyses identified three recessive mutants that underexpress the FLUC reporter, designated jue1, 2 and 3, as well...

  14. Characterization of mutants of yeast sensitive to x rays

    International Nuclear Information System (INIS)

    Strike, T.L.

    1978-01-01

    This study deals with the characterization of mutants at the rad50 to rad57 loci selected on the basis of their sensitivity to x rays. They were also examined for sensitivity to uv and mms and for characteristics of mutation induction, heteroallelic reversion (gene conversion), liquid holding recovery from x rays, and sporulation. All the mutants were slightly to moderately sensitive to uv though they did not show the extreme sensitivity of the rad1 to rad22 mutations, and all demonstrated cross sensitivity to both x rays and MMS. If a mutant was very sensitive to x-rays, it was usually very sensitive to MMS also

  15. Subunit-specific phenotypes of Salmonella typhimurium HU mutants.

    OpenAIRE

    Hillyard, D R; Edlund, M; Hughes, K T; Marsh, M; Higgins, N P

    1990-01-01

    Salmonella hupA and hupB mutants were studied to determine the reasons for the high degree of conservation in HU structure in bacteria. We found one HU-1-specific effect; the F'128 plasmid was 25-fold less stable in hupB compared with hupA or wild-type cells. F' plasmids were 120-fold more unstable in hupA hupB double mutants compared with wild-type cells, and the double mutant also had a significant alteration in plasmid DNA structure. pBR322 DNA isolated from hupA hupB strains was deficient...

  16. Radiation induced mutants in cape-gooseberry (Physalis peruviana L.)

    International Nuclear Information System (INIS)

    Gupta, S.K.; Roy, S.K.

    1986-01-01

    Dry seeds of Physalis peruviana (n=24) were irradiated with different doses of gamma-rays. The M 1 plants were grown to maturity and their seeds collected and sown separately for M 2 generation. Mutants were isolated from M 2 seedlings and plants. Mutant characters obtained were virido-albino chlorophyllous, high yielding, small leaf and fruit, semi-sterile and curly leaf type etc. The high yielding and small leaf and fruit mutants bred true in M 3 and M 4 generation reproducing the characters of the M 2 generation. (author)

  17. Genetic studies with morphological mutants of Aspergillus niger

    International Nuclear Information System (INIS)

    Roy, Ponty; Das, Arati

    1979-01-01

    Three classes of coloured mutations, viz., fawn, yellow and green, occurred recurrently among the population following UV- and γ-radiation from Co 60 of a wild Aspergillus niger strain 350. Ten mutants were picked up and complementation tests were performed by growing them in pairwise combinations. In two cases, allelic mutants of the same colour were observed. All these mutants were again grown in pairwise crosses with a brown A. niger mutant of different lineage. A poor heterokaryotic growth was, however, observed in one combination which later produced a diploid heterozygous nucleus. It segregated spontaneously to develop a large variety of colonies ranging from haploidy to diploidy including aneuploids. These have been analysed genetically and the possible explanations have been given. (auth.)

  18. Gamma ray induced mutants in Colocasia with improved storability

    International Nuclear Information System (INIS)

    Vasudevan, K.; Jos, J.S.; Padmaja, G.

    1989-01-01

    Our mutation induction experiments with Colocasia esculenta (taro) were described before. Poor storability of tubers and acridity of tuber flesh in tubers are problems in taro. While screening for induced mutants, variability in shelf-life of tubers was observed. Tubers of the mutant CM 17 did neither spoil nor lose their viability even after storing for 180 days. Yield and results of quality analyses are presented in the Table in comparison with the control variety C 9 (locally known as ''Thamarakkannan''), the check variety Rasmi (well accepted in Kerala) and another mutant CM 1. Besides high yield and long storability, the mutant CM 17 shows a reduction in phenol and sugar, but an increase in dry matter and starch content which were found to be excellent characteristics for making taro chips as the usual browning phenomenon did not occur

  19. Compact type mutants in apple and sour cherries

    International Nuclear Information System (INIS)

    Zagaja, S.W.; Przybyla, A.

    1976-01-01

    Induction of mutations in deciduous fruits is considered complementary to the conventional breeding methods. Several promissing mutants, particularly in apples, were described and some of them were introduced to commercial orchards. Studies described herein are aimed at developing compact type mutants in apple cultivars, apple rootstocks and in sour cherry cultivars. Data obtained so far confirm the results of the other authors, who developed compact type mutants in apples and sweet cherries. Physiological studies have shown that the leaves of spontaneous apple mutants of compact type are more efficient in photosynthesis than the leaves of respective standards. In spite of this, using branch ringing techniques, it was found that the leaves of compacts and those of standards do not differ in their productivity. There seem to be several advantages in employing tissue culture technique in mutation breeding. That is why a project was started to work out a method of growing apple shoots from adventitious buds developed on sections of roots. (author)

  20. nitrosoguanidine-induced cadmium resistant mutants of Aspergillus

    Indian Academy of Sciences (India)

    Unknown

    nitrosoguanidine-induced cadmium resistant mutants of. Aspergillus niger. SAMAR ... gens and UV irradiation to study transportation of cad- mium ion through cell ..... Rowley W S 1993 Yeast bZib proteins mediate pleiotropic drug and metal ...

  1. Selection of mutants of capsicum annuum induced by gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. I.; Lee, Y. B. [Korea Atomic Energy Research Institute, Taejeon (Korea, Republic of); Lee, E. K. [Chungnam National Univ., Taejeon (Korea, Republic of)

    1998-06-01

    For induction and selection of mutations of Capsicum annuum L., dry seeds of pure lines No.1 and No.2 were irradiated with gamma ray of 150Gy, 200Gy and 250Gy. Various mutants were selected such as showing early maturity, short plant height, long fruit and chlorophyll mutations. Mutation frequency of No.1 line was 3.4% in the dose of 150Gy, while the frequency of No.2 line was 2.7% in the dose of 250Gy. For selection of resistant mutant to amino acid analog, the optimum concentration of 5-methyltryptophan (5-MT) and S-(2-aminoethyl)-L-cysteine were 25 ppm and 30 ppm, respectively. Four resistant mutant lines to 5-MT were selected among 400 mutant lines.

  2. Characterization of a novel curled-cotyledons mutant in soybean ...

    African Journals Online (AJOL)

    ARL

    different stages. Protein and amino acid contents in seeds of mutant are higher than those of the wild .... curled shape, from seedling to maturation phase (Figure. 1D-1F). ..... Arabidopsis seed dermination by stimulating abscisic acid synthesis.

  3. early maturing mutants in Indica rice and their traits

    International Nuclear Information System (INIS)

    Chen Xiulan; He Zhentian; Han Yuepeng; Liu Xueyu; Yang Hefeng; Xu Chenwu; Gu Shiliang

    1998-01-01

    The correlation and genetic parameters of eleven agronomic characters of 50 early mature lines induced from late mature cultivar, IR 1529-68-3-2 were studied by morphological classification and correlation and regression analysis. The results showed that: 1. The early mutants could be divided into two ecotype: early mature type and medium mature type of mid-maturity rice. 2. The 1000-grain weight of early mutants negatively correlated with the length of growing period. 3. According to direct path coefficients, the relation with heading period of early mutants was in order of 1000-grain-weight>plant height>seed sterility. 4.The higher heritability in broad sense were found in plant height, 1000 grain weight and heading period of the early mutants

  4. Characteristics of the repair - deficient mutants 1435 plague microbe strain

    International Nuclear Information System (INIS)

    Temiralieva, G.A.

    1977-01-01

    Repair-deficient mutants 1435 A uvr - hcr - , 1435-17 uvr - hcr + and 1435-35 lon have been obtained from 1435 plague microbe strain, isolated from a large gerbil living in the Central Asian desert region. The mutants have the same cultural-morphological and enzymatic characteristics, the same need in growth factors and similar virulence determinants as the original strain, but they do not cause death of the experimental animals

  5. High yielding small grain mutant of rice variety Pankaj

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-07-01

    Full text: By treatment with EMS a mutant has been produced from the variety Pankaj which has better tillering, longer panicle and more grains per panicle. In multilocation trials at Burdwan, Suri and Rampurhat in West Bengal it yielded significantly more than Pankaj and Mahsuri at all locations, with a mean 5.2t. The mutant named BU 79 would be a suitable substitute for Pankaj and similar long-duration rices. (author)

  6. Investigations on gamma ray induced chlorophyll variegated mutants

    International Nuclear Information System (INIS)

    Datta, S.K.; Dwivedi, A.K.; Banerji, B.K.

    1995-01-01

    Considering economic importance of chlorophyll variegation in floriculture trade an attempt was made for cytological, anatomical and biochemical analysis of four Bougainvillea and Lantana depressa chlorophyll variegated mutants for better and clear understanding of origin of chlorophyll variegation. No cytological evidence could be detected for their origin. Anatomical and biochemical examinations revealed that chlorophyll variegation in these mutants were due to changes in biosynthesis pathways and time of chlorophyll synthesis in palisade and spongy mesophyll cells. (author). 7 refs., 3 figs., 3 tabs

  7. Semi-dwarf mutants in triticale and wheat breeding

    International Nuclear Information System (INIS)

    Driscoll, C.J.

    1984-01-01

    The triticale lines Beagle and DR-IRA have been subjected to ionizing irradiation and chemical mutagenesis in order to produce semi-dwarf mutants. Beagle is 100 cm tall and DR-IRA 80 cm under average field conditions. A bulk then pedigree method is currently represented by 158 single plots of M 6 (or in some cases M 7 ) mutants that are from 5 to 35 cm shorter than the control variety. The shortest mutants are 65 cm in height. Forty of these mutants are also earlier flowering than the control varieties. Replicated yield testing will be conducted on confirmed mutants in 1983. Response to gibberellic acid of these mutants will also be determined. The Cornerstone male-sterility mutant (ms1c) on chromosome arm 4Aα has been combined with the GA-insensitive/reduced height gene Gai/Rht1 which is also on chromosome arm 4Aα. The ms1c mutant has also been combined with Gai/Rht2 on chromosome 4D and with both Gai/Rht1 and Gai/Rht2. The combination ms1c and Gai/Rht1 has been chosen as the basis of a composite cross. Thirteen varieties were tested with GA 3 and seven (Warigal, Aroona, Oxley, Banks, Avocet, Matipo and Toquifen) which contain Gai/Rht1 were crossed with ms1c Gai/Rht1 and entered into an interpollinating F 2 . The entire composite is homozygous for this semi-dwarf allele and selection will be practiced for increased height on a GA-insensitive background. (author)

  8. X-ray-induced mutants resistant to 8-azaguanine

    International Nuclear Information System (INIS)

    Carver, J.H.; Dewey, W.C.; Hopwood, L.E.

    1976-01-01

    Asynchronous Chinese hamster ovary cells were irradiated and colony survival in Alpha MEM medium with dialyzed serum was determined with or without 15 μg/ml 8-Azaguanine (AG). Data indicated that a reproducible assay for the system was dependent upon controlling cell density at least two days prior to induction as well as throughout the expression period. Generally, spontaneous and radiation-induced mutant frequencies decreased when cell densities exceeded a critical density of 3-6 x 10 4 cells/cm 2 . Infrequently, the critical density was exceeded by a factor of two with no observed decrease, possibly correlated with a longer cell doubling time. Drug depletion artifacts can occur because of drug degradation, or because wild-type cells utilize the drug or produce conditions which reduce uptake of the drug. Thus, as the effective drug concentration is lowered, the observed mutant frequency increases because a spectrum of mutants resistant to only low concentrations can now survive. In fact, refeeding with AG at intervals during the incubation period lowered spontaneous and radiation-induced frequencies approx. 5-fold. Therefore, to standardize conditions, cells were trypsinized at the end of the expression time and replated at a constant cell number for mutant selection by AG. Over two generations of growth during the expression period were required for optimal manifestation of induced mutants, and when densities were kept below 4 x 10 4 cells/cm 2 at all times, observed mutant frequencies did not change significantly over a period between 80 and 140 h post-induction (over 4 generations for irradiated cells and over 6 generations for controls). Previous reports of observed mutant frequencies decreasing beyond three generations may be due to cell interaction prior to mutant selection

  9. Development of compact mutants in apple and sour cherry

    International Nuclear Information System (INIS)

    Zagaja, S.W.; Przybyla, A.; Machnik, B.

    1982-01-01

    During the period 1973 - 79 studies were conducted with the aim of developing compact mutants in apple and cherry cultivars and in apple vegetative rootstocks. During the investigations the effect of the dose of gamma rays on frequency of the mutants was studied. Attempts were also made to evolve a micropropagation technique adapted to propagate P 2 and P 22 apple rootstocks, as an aid in mutation breeding. Several mutants were produced in all the material studied, but none of them have yet reached a sufficient developmental stage to enable their complete assessment. On the basis of the results obtained so far the following conclusions can be drawn: higher doses of irradiation resulted in higher frequency of mutants in most apple cultivars and apple rootstocks; in sour cherries the effect of dose depended on the cultivars. Among V 1 shoots developed from sleeping buds on irradiated scion wood, compact mutants were found; their frequency, however, was about 60% lower than among V 1 shoots developed directly from irradiated dormant buds. In apple rootstocks A 2 and M 26 several dwarfed mutants were found; some of these produced thorny plants and some had lower rooting ability; both these characteristics are inferior from the practical point of view. Multiplication and rooting media for in vitro propagation of apple rootstocks, worked out for M 26, were found unsuitable for the rootstocks P 2 and P 22; modifications made in the growth substance composition of the above media enabled satisfactory propagation to be obtained. (author)

  10. A wheat cold resistance mutant derived from space mutagenesis

    International Nuclear Information System (INIS)

    Li Peng; Sun Mingzhu; Zhang Fengyun; Gao Guoqiang; Qiu Denglin; Li Xinhua

    2012-01-01

    A cold resistance mutant, obtained by spaceflight mutagenesis on the seeds of wheat variety Han6172, and the DNA of cold resistance mutant and contrast Han6172 were compared by SRAP technique. 380 pairs of primers were screened, 6 pairs of them had polymorphisms between mutant and contrast, the rate was 1.58%, and this data indicated that there are no obvious DNA differences between mutant and contrast Six specific fragments were obtained, 3 fragments of them were amplified in mutant. Homology analysis in GenBank showed that Me3-Em7-Mt, Me4-Em11-CK, Me7-Em19-CK and Me6-Em9-Mt all had homologous sequences with wheat chromosome 3B-specific BAC library, and this result indicated that the gene and regulator sequences associated with mutant cold resistance might locate on 3B chromosome. It was speculated that space mutation induced the mutation of 3B chromosome primary structure, and influenced the expressions of cold resistance genes, which resulted in the mutation of cold resistance ability. (authors)

  11. Proteomic analysis of the flooding tolerance mechanism in mutant soybean.

    Science.gov (United States)

    Komatsu, Setsuko; Nanjo, Yohei; Nishimura, Minoru

    2013-02-21

    Flooding stress of soybean is a serious problem because it reduces growth; however, flooding-tolerant cultivars have not been identified. To analyze the flooding tolerance mechanism of soybean, the flooding-tolerant mutant was isolated and analyzed using a proteomic technique. Flooding-tolerance tests were repeated five times using gamma-ray irradiated soybeans, whose root growth (M6 stage) was not suppressed even under flooding stress. Two-day-old wild-type and mutant plants were subjected to flooding stress for 2days, and proteins were identified using a gel-based proteomic technique. In wild-type under flooding stress, levels of proteins related to development, protein synthesis/degradation, secondary metabolism, and the cell wall changed; however, these proteins did not markedly differ in the mutant. In contrast, an increased number of fermentation-related proteins were identified in the mutant under flooding stress. The root tips of mutant plants were not affected by flooding stress, even though the wild-type plants had damaged root. Alcohol dehydrogenase activity in the mutant increased at an early stage of flooding stress compared with that of the wild-type. Taken together, these results suggest that activation of the fermentation system in the early stages of flooding may be an important factor for the acquisition of flooding tolerance in soybean. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Sodium azide mutagenesis in wheat: Mutants with golden glumes

    International Nuclear Information System (INIS)

    Siddiqui, K.A.; Jafri, K.A.; Arain, M.A.

    1989-01-01

    In bread wheat, Triticum aestivum L. (2n=6x=42, AABBDD), detection of induced mutations is hampered by the presence of duplicate and triplicate genes. Induced changes in spike characteristics are known, but mutants with changed glume colour do not seem to have been reported. Physical mutagens such as gamma rays, thermal neutrons and fast neutrons, and chemical mutagens like EMS, El, dES and NEH have been extensively used for induction of mutations in bread wheat but it seems as if these mutagens did not induce mutants with changed glume colour. We used sodium azide for inducing mutations in the widely adapted cultivar 'Sonalika', which is characterized by brown glume colour. Presoaked seeds were treated with 0.2M sodium azide for 3 hours. Three spikes were harvested from each M 1 plant. M 2 generation was space-planted as spike progeny. We were successful in identifying 3 mutants with golden glumes. The mutants resemble 'Sonalika' in other spike characteristics. The mutants glume colour was confirmed in M 3 . The mutants were also evaluated for agronomically important characteristics. Some characters were significantly different from the parent. Glume colours may be useful as genetic markers since such characters are less influenced by the environment. Our investigation confirms that also agronomically useful genetic variation may be readily induced in bread wheat through sodium azide

  13. Inactivation of carbenicillin by some radioresistant mutant strains

    International Nuclear Information System (INIS)

    Zahiera, T.S.; Mahmoud, M.I.; Bashandy, A.A.

    1990-01-01

    Sensitivity test of five bacterial species to carbenicillin was performed microbiologically. The bacterial species were previously isolated from high level radiation environment. All the studied species could either highly decrease the antibiotic activity or even inactivate it completely. Detailed study of the inactivation of carbenicillin by the radioresistant mutant strains B. Laterosporus, B. firmus and M. roseus was performed, in the present study. Using high performace liquid chromatography technique. The gram-positive m. roseus mutant strain seemed to be the most active mutant in degrading the antibiotic. The left over of the antibiotic attained a value of 9% of the original amount after 14 day incubation of the antibiotic with this mutant strain, while the value of the left over reached 36% and 32% after the same period of incubation with the mutants B. laterosporus and B. firmus respectively. In the case of bacillus species, the degradation of the antibiotic started at the same moment when it was added to the bacterial cultures. This fact may indicate that the inactivation of the studied antibiotic by these bacillus species was due to extracellular enzymes extracted rapidly in the surrounding medium. In the case of M. roseus the inactivation process started later. after the addition of the antibiotic to the mutant culture

  14. Leaf and canopy photosynthesis of a chlorophyll deficient soybean mutant.

    Science.gov (United States)

    Sakowska, Karolina; Alberti, Giorgio; Genesio, Lorenzo; Peressotti, Alessandro; Delle Vedove, Gemini; Gianelle, Damiano; Colombo, Roberto; Rodeghiero, Mirco; Panigada, Cinzia; Juszczak, Radosław; Celesti, Marco; Rossini, Micol; Haworth, Matthew; Campbell, Benjamin W; Mevy, Jean-Philippe; Vescovo, Loris; Cendrero-Mateo, M Pilar; Rascher, Uwe; Miglietta, Franco

    2018-03-02

    The photosynthetic, optical, and morphological characteristics of a chlorophyll-deficient (Chl-deficient) "yellow" soybean mutant (MinnGold) were examined in comparison with 2 green varieties (MN0095 and Eiko). Despite the large difference in Chl content, similar leaf photosynthesis rates were maintained in the Chl-deficient mutant by offsetting the reduced absorption of red photons by a small increase in photochemical efficiency and lower non-photochemical quenching. When grown in the field, at full canopy cover, the mutants reflected a significantly larger proportion of incoming shortwave radiation, but the total canopy light absorption was only slightly reduced, most likely due to a deeper penetration of light into the canopy space. As a consequence, canopy-scale gross primary production and ecosystem respiration were comparable between the Chl-deficient mutant and the green variety. However, total biomass production was lower in the mutant, which indicates that processes other than steady state photosynthesis caused a reduction in biomass accumulation over time. Analysis of non-photochemical quenching relaxation and gas exchange in Chl-deficient and green leaves after transitions from high to low light conditions suggested that dynamic photosynthesis might be responsible for the reduced biomass production in the Chl-deficient mutant under field conditions. © 2018 John Wiley & Sons Ltd.

  15. A wheat cold resistance mutant derived from space mutagenesis

    International Nuclear Information System (INIS)

    Li Peng; Sun Mingzhu; Zhang Fengyun; Gao Guoqiang; Qiu Denglin; Li Xinhua

    2011-01-01

    A cold resistance mutant, obtained by spaceflight mutagenesis on the seeds of wheat variety Han6172, and the DNA of cold resistance mutant and contrast Han6172 were compared by SRAP technique. 380 pairs of primers were screened, 6 pairs of them had polymorphisms between mutant and contrast, the rate was 1.58%, and this data indicated that there are no obvious DNA differences between mutant and contrast. Six specific fragments were obtained, 3 fragments of them were amplified in mutant. Homology analysis in GenBank showed that Me3-Em7-Mt, Me4-Em11-CK, Me7-Em19-CK and Me6-Em9-Mt all had homologous sequences with wheat chromosome 3B-specific BAC library, and this result indicated that the gene and regulator sequences associated with mutant cold resistance might locate on 3B chromosome. It was speculated that space mutation induced the mutation of 3B chromosome primary structure, and influenced the expressions of cold resistance genes, which resulted in the mutation of cold resistance ability. (authors)

  16. Gamma ray induced male sterility mutant in lentil

    International Nuclear Information System (INIS)

    Srivastava, A.; Yadav, A.K.

    2001-01-01

    Full text: Male sterility refers to the failure of pollen grains to bring about effective fertilization, either due to structural default or physiological disfunctioning and has special significance in hybridization programmes. Male steriles have been produced in a number of crop plants like red gram, pigeon pea, mung bean, khesari and lentil. A completely male sterile mutant was isolated in Lens culinaris Medik, after seed treatment with 100 Gy dose of gamma rays. The male sterile mutant showed 100% pollen sterility but was morphologically more vigorous than the parent plants. It showed more branches and its leaves were bigger, more oblong and dark green. The number of flowers borne by the mutant was significantly higher than any other plant of the treatment. The size of the flowers was also increased but the anthers were smaller in size. Pollen grains were few in number, round in shape but empty and did not take up any stain, indicating that normal microsporogenesis had not taken place. This male sterile mutant was used as the female parent and pollinated with pollen of a parent. Four pods with one seed in each were formed indicating that the mutant was female fertile. The seeds were smaller than those of the parent variety and also dark coloured. The mutant showed increased vigour and flower number as compared to parental plants. Lentil is an important pulse crop and induction of variability in its germplasm is necessary for its improvement. Male steriles can be used conveniently in lentil hybridization programmes. (author)

  17. Mutation induction and evaluation of high yield rice mutants

    International Nuclear Information System (INIS)

    Abdul Rahim Harun; Sobri Husein; Rusli Ibrahim

    2006-01-01

    The successful use of plant breeding for improving crops requires the existence of genetic variation of useful traits. Unfortunately, the desired variation is often lacking. However, radiation has been used to induce mutations and thereby generate genetic variation from which desired mutants may be selected. Mutation induction has become a proven way of creating variation within a crop variety. It offers the possibility of inducing desired attributes that either cannot be expressed in nature or have been lost during evolution. Rice is security food crop in Malaysia. Efforts were undertaken to enhance rice yield from 4.0 tones per hectare in 1995 to 5.5 tones per hectare in 2010. Proper management and good varieties are two factors that require for enhancing yield of rice. In this research, purified seeds of MR211 and MR219 were gamma irradiated at 100 to 400 Gray and sown for planting as M1 generation at MARDI experimental plot. The M2 population was sown in bulk with population size around 15,000 to 20,000 plants. Individual plant selection was carried out at maturity and each selected plant became a mutant line of M3 generation. Agronomic trial of M3 mutants lines were conducted in Mardi, Tanjung Karang, Selangor. About 115 of selected mutant lines were evaluated. Each row of those mutant lines were planted in two rows at planting distance of 25cm within and between rows. These mutant lines were visually observed and data were recorded in each of every mutant line. (Author)

  18. Defective glycinergic synaptic transmission in zebrafish motility mutants

    Directory of Open Access Journals (Sweden)

    Hiromi Hirata

    2010-01-01

    Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

  19. Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

    Science.gov (United States)

    Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

    2009-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho) mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch-once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch-once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs. PMID:20161699

  20. Biochemical characteristics of mutant lines of currant tomato

    International Nuclear Information System (INIS)

    Gorbatenko, I.Yu.; Khrustaleva, V.V.; Shcherbakov, V.K.

    1988-01-01

    The currant tomato is used in breeding for fruit quality. It contains up to 50 mg% ascorbic acid, a large quantity of sugar and 8-10% of dry matter. The weight of the fruit, however, does not exceed 1.2-1.5 g. The plants have long, spreading and very branchy stems. Gamma ray induced mutants of currant tomato were used, as initial material in breeding for fruit quality in varieties suitable for mechanized harvesting. The research was carried out mainly at the Department of Vegetable Growing Ukrainian Scientific Research Institute of Irrigation Farming. The regional variety Lebyazhinskij (suitable for mechanized harvesting) was adopted as the standard. Its fruits contain: 5.6% dry matter, 2.7% sugars, 0.543% titrated acidity, 26.6 mg/100 g ascorbic acid, 0.425 mg% carotene and 0.35% cellulose. The biochemical characteristics of the tomato mutants are shown. In terms of fruit dry matter, all mutants surpassed the standard. The acidity and the ascorbic acid content varied considerably. Most noteworthy in terms of carotene were the lines GP-5, GP-9 and GP-12. An important factor in the production of tomato paste is the fruit cellulose content. The lowest cellulose content is found in mutant GP-3. As shown, all of the mutants were early ripening. The mutants surpassed the standard in simultaneous fruit ripening. Mutant lines GP-3, GP-6, GP-9 and GP-12 will be used in the breeding programme for improving fruit quality of varieties suitable for mechanized harvesting

  1. Development Of New Chrysanthemum Mutants For Malaysian Floriculture Industry

    International Nuclear Information System (INIS)

    Zaiton Ahmad; Affrida Abu Hassan; Shakinah Salleh; Nurul Hidayah Mahmud; Shuhaimi Shamsudin; Mohamed Najli Mohamed Yasin

    2014-01-01

    This five-year project was in collaboration with Japan Atomic Energy Agency (JAEA) under the Bilateral Cooperative Research Program and was partly funded by Ministry of Agriculture and Agro-Based Industry (MOA) under Agriculture R&D Fund. The main objective was to produce new chrysanthemum varieties with good horticultural traits especially for cut flower production. In this project, tissue culture samples of chrysanthemum (red and pink varieties) were sent to JAEA for ion beam irradiations. Plant regeneration and multiplication were carried out at Nuclear Malaysia whilst field screenings for morphological characteristics were done at MARDI Cameron Highlands. Through this project, a number of stable chrysanthemum mutants with various new features have been generated and of these, 8 mutants were selected based on their uniqueness and/or suitability for cut flower production. In preparation for future commercialization process, five of these mutants have been filed for plant variety protection with Department of Agriculture Malaysia and a similar process in Japan is also under consideration. In addition, molecular marker work to fingerprint these mutants has also been initiated and future research may also include development of markers for selected horticultural traits and isolation of unique mutant genes. (author)

  2. Characterization of MMS-sensitive mutants of Neurospora crassa

    Energy Technology Data Exchange (ETDEWEB)

    DeLange, A.M.; Mishra, N.C.

    1982-01-01

    Several MMS-sensitive mutants of Neurospora crassa were compared with the wild-type strain for their relative sensitivities to UV, X-ray, and histidine. They were also compared for the frequency of spontaneous mutation at the loci which confer resistance to p-fluorophenylalanine. The mutants were also examined for possible defects in meiotic behavior in homozygous crosses and for any change in the inducible DNA salvage pathways. On the basis of these characterizations, the present MMS-sensitive mutants of Neurospora can be placed into three groups. On the basis of data presented, the MMS sensitivity of the first group mutants cannot be ascertained to arise from a defect in the DNA repair pathways; instead, it may stem from altered cell permeability or other pleotropic effects of the mus mutations. However, it can be suggested that the second and third group of mus mutants may indeed result from a defect in the DNA repair pathways controlled by the mus genes; this conclusion is based on their cross-sensitivity to a number of DNA-damaging agents such as MMS, UV and/or X-rays, high frequencies of spontaneous mutation and defects in meiotic behavior.

  3. Promising mutant variety of rice evolved through gamma irradiation

    International Nuclear Information System (INIS)

    Prasad, S.C.; Sinha, S.K.

    1980-01-01

    Rice occupies a major share in crop production in the Chotanagpur plateau of Bihar State. Uplands are roughly 40% in area where traditional low yielding rice, known as ''gora'' is cultivated as directly sown crop. Despite introduction of high yielding rice varieties, gora group of rices continue to prevail. It is therefore desired to increase the productivity level of the gora rice by mutation breeding. One such mutant known as ''gora mutant'' was obtained through gamma irradiation (10 kR) of variety Brown gora. The maturity of both parent and mutant remaining constant (ie. 100 days), there is some improvement in other characteristics like plant height, tillering capacity and kernel character. The parent being tall, shy in tillering and red bold kernel, the mutant has dwarfish characteristics, profuse tillering habit and white kernel with fine grains. The yielding capacity of mutant derivative is 30-40% higher than the parent Brown gora. This variety is in pre-release stage, and the farmers have taken great liking for it. (author)

  4. Pollen irradiation method to obtain mutants in cucumber

    International Nuclear Information System (INIS)

    Iida, S.; Amano, E.

    1988-01-01

    Seed irradiation for mutation induction in dioecious crops like cucumber is not very useful because chimerism of the mutated tissues makes the segregation of mutants in the M 2 generation nearly impossible. This problem does not exist with pollen irradiation. Cucumber (Cucumis sativus L. var. Nishikisuyo) was used for a model experiment. The petals of male and female flowers were closed by pinching with binding wire before flowering to prevent pollination by insects. On the flowering day, the male flowers were collected and irradiated with 1kR to 10 kR of acute gamma rays (137-Cs), then used to pollinate the female flowers. The M 1 seeds thus obtained are not chimeric but heterozygous for induced mutations. When planted, no mutant phenotype appeared. Selfing within a plant lead to segregation of mutants in the M 2 generation. Seedling examination revealed eight mutants. One mutant line, in which the shape of leaves changed from pentagonal to round heart shape, was found under field conditions. The optimal dose for pollen irradiation seems to be between 2 kR and 4kR

  5. Mutant number distribution in an exponentially growing population

    Science.gov (United States)

    Keller, Peter; Antal, Tibor

    2015-01-01

    We present an explicit solution to a classic model of cell-population growth introduced by Luria and Delbrück (1943 Genetics 28 491-511) 70 years ago to study the emergence of mutations in bacterial populations. In this model a wild-type population is assumed to grow exponentially in a deterministic fashion. Proportional to the wild-type population size, mutants arrive randomly and initiate new sub-populations of mutants that grow stochastically according to a supercritical birth and death process. We give an exact expression for the generating function of the total number of mutants at a given wild-type population size. We present a simple expression for the probability of finding no mutants, and a recursion formula for the probability of finding a given number of mutants. In the ‘large population-small mutation’ limit we recover recent results of Kessler and Levine (2014 J. Stat. Phys. doi:10.1007/s10955-014-1143-3) for a fully stochastic version of the process.

  6. Mutant number distribution in an exponentially growing population

    International Nuclear Information System (INIS)

    Keller, Peter; Antal, Tibor

    2015-01-01

    We present an explicit solution to a classic model of cell-population growth introduced by Luria and Delbrück (1943 Genetics 28 491–511) 70 years ago to study the emergence of mutations in bacterial populations. In this model a wild-type population is assumed to grow exponentially in a deterministic fashion. Proportional to the wild-type population size, mutants arrive randomly and initiate new sub-populations of mutants that grow stochastically according to a supercritical birth and death process. We give an exact expression for the generating function of the total number of mutants at a given wild-type population size. We present a simple expression for the probability of finding no mutants, and a recursion formula for the probability of finding a given number of mutants. In the ‘large population-small mutation’ limit we recover recent results of Kessler and Levine (2014 J. Stat. Phys. doi:10.1007/s10955-014-1143-3) for a fully stochastic version of the process. (paper)

  7. A preliminary yield trial of some soybean mutant lines

    International Nuclear Information System (INIS)

    Ratma, Rivaie

    1985-01-01

    A preliminary yield trial of some soybean mutant lines, derived from irradiated Orba variety with dose of 0.40 kGy, were carried out during the wet and dry season in 1979-1982 in Muara and Citayam, Bogor. The result obtained showed that yield potential of mutant lines no. M6/40/10 was higher than that of the control in dry season in 1979 as well as in the wet season of 1979/80 in Muara. Whereas, the yield potential of the mutant lines no. M6/40/8 and no. M6/40/14 were higher than that of the control only in the wet season. The yield potential of semi dwarf mutant lines no. M6/40/68 was highly significant compared to that of the control in dry season in Muara and the wet season in 1981/82 in Citayam. Whereas, the yield potential of the mutant lines no. M6/40/69 was higher yield compared to that of the control in dry season in 1981 in Muara. (author). 10 refs

  8. Analysis of AtCry1 and Mutants

    Science.gov (United States)

    Burdick, Derek; Purvis, Adam; Ahmad, Margaret; Link, Justin J.; Engle, Dorothy

    Cryptochrome is an incredibly versatile protein that influences numerous biological processes such as plant growth, bird migration, and sleep cycles. Due to the versatility of this protein, understanding the mechanism would allow for advances in numerous fields such as crop growth, animal behavior, and sleep disorders. It is known that cryptochrome requires blue light to function, but the exact processes in the regulation of biological activity are still not fully understood. It is believed that the c-terminal domain of the protein undergoes a conformational change when exposed to blue light which allows for biological function. Three different non-functioning mutants were tested during this study to gain insight on the mechanism of cryptochrome. Absorbance spectra showed a difference between two of the mutants and the wild type with one mutant showing little difference. Immunoprecipitation experiments were also conducted to identify the different c-terminal responses of the mutants. By studying non functioning mutants of this protein, the mechanism of the protein can be further characterized. This two-month research experience in Paris allowed us to experience international and interdisciplinary collaborations in science and immerse in a different culture. The Borcer Fund for Student Research, Xavier University, Cincinnati, OH, and John Hauck Foundation.

  9. Productive mutants in lemongrass induced by gamma rays

    International Nuclear Information System (INIS)

    Gopinathan Nair, V.

    1980-01-01

    Seeds of the lemongrass variety O.D. 19 were irradiated with gamma rays at a dose range of 5 to 30 krad. M 1 plants with one or a few tillers differing from the standard plants of O.D. 19 were selected, split into single slips and planted as clonal progenies. Mutants were isolated in M 1 V 1 and carried forward. Forty two M 1 V 2 mutant clones differing from O.D. 19 in morphological characters such as vigour, plant height, growth habit, pigmentation and number of tillers have been established. These were evaluated for tiller number, grass yield and oil content. Six clones gave higher grass yield, the highest being 556 gm per plant per cutting as against 360 gm in the standard. Five clones gave higher oil yield, the highest being 0.42% as against 0.23% in the standard. Isolation of viable mutants with high grass yield and essential oil content indicate the scope for evolving productive mutant varieties in this perennial aromatic grass. The eleven M 1 V 2 mutant clones are being critically evaluated by estimating oil yield per hectare per year. (author)

  10. Normal aging modulates the neurotoxicity of mutant huntingtin.

    Directory of Open Access Journals (Sweden)

    Elsa Diguet

    Full Text Available Aging likely plays a role in neurodegenerative disorders. In Huntington's disease (HD, a disorder caused by an abnormal expansion of a polyglutamine tract in the protein huntingtin (Htt, the role of aging is unclear. For a given tract length, the probability of disease onset increases with age. There are mainly two hypotheses that could explain adult onset in HD: Either mutant Htt progressively produces cumulative defects over time or "normal" aging renders neurons more vulnerable to mutant Htt toxicity. In the present study, we directly explored whether aging affected the toxicity of mutant Htt in vivo. We studied the impact of aging on the effects produced by overexpression of an N-terminal fragment of mutant Htt, of wild-type Htt or of a beta-Galactosidase (beta-Gal reporter gene in the rat striatum. Stereotaxic injections of lentiviral vectors were performed simultaneously in young (3 week and old (15 month rats. Histological evaluation at different time points after infection demonstrated that the expression of mutant Htt led to pathological changes that were more severe in old rats, including an increase in the number of small Htt-containing aggregates in the neuropil, a greater loss of DARPP-32 immunoreactivity and striatal neurons as assessed by unbiased stereological counts.The present results support the hypothesis that "normal" aging is involved in HD pathogenesis, and suggest that age-related cellular defects might constitute potential therapeutic targets for HD.

  11. Results of the use of induced mutants in maize breeding

    International Nuclear Information System (INIS)

    Balint, A.; Kovacs, Gezane; Hajos, Laszlone; Geczki, I.

    1979-01-01

    The investigated mutagens have the same effect on the increasing of protein content. In the case of WF9 mutants no essential improvement can be found compared with the untreated co trol selected for protein. ''Lines'' flowering 16-19 days earlier than controls were produced; the most effective agent of this production is the fast neutron. Mutation caused a significant change in their combining ability, but there were more negative variants than positive ones. Three hybrids with stronger stalk than that of MvSc 620 were obtained. Stalk standing ability of mutants did not improve. The flowering date of lines (male) is in r=+0.5672 +++ correlation to the yield of their test hybrid. Mutant lines in SC test cross seemed to be stable. The correlation of the yield of two years is r=+0.8659. The correlation of both the yield of test hybrids to the protein content of mutant lines (r=0.2307) and the flowering date of lines to their protein content (r=-0.3032) is loose. The earliest mutant line of WF9, which produced low crop (5000 kg/ha) when crossed with N6, gave a high-yielding hybrid when crossed with other lines. The average yield of eight combinations was 10050 kg/ha and the highest yield was 11680 kg/ha. (author)

  12. Selection of high hectolitre weight mutants of winter wheat

    International Nuclear Information System (INIS)

    Crowley, C.; Jones, P.

    1989-01-01

    Grain quality in wheat includes hectolitre weight (HLW) besides protein content and thousand-grain weight (TGW). The British winter wheat variety ''Guardian'' has a very high yield potential. Although the long grain of ''Guardian'' results in a desirable high TGW the HLW is too low. To select mutants exhibiting increased HLW the character was first analyzed to identify traits that could more easily be screened for using M 2 seeds. In comparison of 6 wheat cultivars, correlation analyses with HLW resulted in coefficients of -0.86 (grain length, L:P 2 seeds for shorter, less prolate grains. Mutagenesis was carried out using EMS sulphonate (1.8 or 3.6%), sodium azide (2 or 20 mM) or X-rays (7.5 or 20 kR). 69 M 2 grains with altered shape were selected. Examination of the M 3 progeny confirmed 6 grain-shape mutants, most of them resulting from EMS treatment (Table). Two of the mutants showed TGW values significantly below the parental variety, but three mutants exhibited HLW and TGW values significantly greater than those of the parental variety. Microplot yield trails on selected M 3 lines are in progress. The influence of physical grain characteristics on HLW offers prospects for mechanical fractionation of large M 2 populations. The application of gravity separators (fractionation on the basis of grain density) and sieves (fractionation on the basis of grain length) in screening mutants possessing improved grain quality is being investigated

  13. Purkinje Cell Compartmentation in the Cerebellum of the Lysosomal Acid Phosphatase 2 Mutant Mouse (Nax - Naked-Ataxia Mutant Mouse)

    Science.gov (United States)

    Bailey, Karen; Rahimi Balaei, Maryam; Mannan, Ashraf; Del Bigio, Marc R.; Marzban, Hassan

    2014-01-01

    The Acp2 gene encodes the beta subunit of lysosomal acid phosphatase, which is an isoenzyme that hydrolyzes orthophosphoric monoesters. In mice, a spontaneous mutation in Acp2 results in severe cerebellar defects. These include a reduced size, abnormal lobulation, and an apparent anterior cerebellar disorder with an absent or hypoplastic vermis. Based on differential gene expression in the cerebellum, the mouse cerebellar cortex can normally be compartmentalized anteroposteriorly into four transverse zones and mediolaterally into parasagittal stripes. In this study, immunohistochemistry was performed using various Purkinje cell compartmentation markers to examine their expression patterns in the Acp2 mutant. Despite the abnormal lobulation and anterior cerebellar defects, zebrin II and PLCβ4 showed similar expression patterns in the nax mutant and wild type cerebellum. However, fewer stripes were found in the anterior zone of the nax mutant, which could be due to a lack of Purkinje cells or altered expression of the stripe markers. HSP25 expression was uniform in the central zone of the nax mutant cerebellum at around postnatal day (P) 18–19, suggesting that HSP25 immunonegative Purkinje cells are absent or delayed in stripe pattern expression compared to the wild type. HSP25 expression became heterogeneous around P22–23, with twice the number of parasagittal stripes in the nax mutant compared to the wild type. Aside from reduced size and cortical disorganization, both the posterior zone and nodular zone in the nax mutant appeared less abnormal than the rest of the cerebellum. From these results, it is evident that the anterior zone of the nax mutant cerebellum is the most severely affected, and this extends beyond the primary fissure into the rostral central zone/vermis. This suggests that ACP2 has critical roles in the development of the anterior cerebellum and it may regulate anterior and central zone compartmentation. PMID:24722417

  14. An induced early mutant in finger millet Eleusin coranaca Gaertn

    International Nuclear Information System (INIS)

    Shivashankar, G.; Kempanna, C.; Viswanatha, S.R.

    1975-01-01

    Among the several collections of ragi (Eleusine coracana. Gaertn.) from all over the world, the strain 'H.E.S.927' has been found to be the highest yielder compared to other cultivars. Mutation studies have been conducted on this variety at Bangalore in India to make it suitable for the rainfall pattern of the ragi tract of the Karnataka state. A mutant induced by gamma radiation at 30 K rad has been stabilized. This mutant is early by 30-35 days with comparatively better straw quality. Various morphological characters concerning the yield and yield attributes and the possibility of exploiting it as a genotype for future breeding work and as a promising variety is discussed. Another promising mutant with earhead measuring 15 cm as against the earhead length of 5 to 10 cm of the cultivated varieties is illustrated. (K.B.)

  15. Mutant fatty acid desaturase and methods for directed mutagenesis

    Science.gov (United States)

    Shanklin, John [Shoreham, NY; Whittle, Edward J [Greenport, NY

    2008-01-29

    The present invention relates to methods for producing fatty acid desaturase mutants having a substantially increased activity towards substrates with fewer than 18 carbon atom chains relative to an unmutagenized precursor desaturase having an 18 carbon chain length specificity, the sequences encoding the desaturases and to the desaturases that are produced by the methods. The present invention further relates to a method for altering a function of a protein, including a fatty acid desaturase, through directed mutagenesis involving identifying candidate amino acid residues, producing a library of mutants of the protein by simultaneously randomizing all amino acid candidates, and selecting for mutants which exhibit the desired alteration of function. Candidate amino acids are identified by a combination of methods. Enzymatic, binding, structural and other functions of proteins can be altered by the method.

  16. Nonsense mutants in the bacteriophage T4D v gene

    Energy Technology Data Exchange (ETDEWEB)

    Minderhout, L van; Grimbergen, J; Groot, B de [Rijksuniversiteit Leiden (Netherlands). Lab. voor Stralengenetica en Chemische Mutagenese; Cohen (J.A.) Instituut voor Radiopathologie en Stralenbescherming, Leiden (Netherlands))

    1975-09-01

    Ten UV-sensitive mutants of T4D with the v phenotype were isolated. Of these ten mutants, two are amber and two opal. In UV curves and in photoreactivation and multiplicity reactivation experiments the nonsense mutants show the v phenotype in su/sup -/ hosts and almost the T4/sup +/ phenotype in su/sup +/ hosts. The mutations are located between rl and e and are alleles of v/sub 1/. In crosses with irradiated and non-irradiated phages the recombinant frequency is not reduced by uvs5. Amber uvs5 propagated in CR63 su/sup +/ is with B su/sup -/ just as sensitive to UV as uvs5 propagated in B su/sup -/, which permits the conclusion that the capsid of T4 phage particles does not contain the v gene product.

  17. Sensorimotor learning in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Lalonde, R; Strazielle, C

    2011-04-15

    Homozygous Dab1(scm) mouse mutants with cell ectopias in cerebellar cortex and neocortex were compared with non-ataxic controls on two tests of motor coordination: rotorod and grid climbing. Even at the minimal speed of 4 rpm and unlike controls, none of the Dab1(scm) mutants reached criterion on the constant speed rotorod. In contrast, Dab1(scm) mutants improved their performances on the vertical grid over the course of the same number of trials. Thus, despite massive cerebellar degeneration, sensorimotor learning for equilibrium is still possible, indicating the potential usefulness of the grid-climbing test in determining residual functions in mice with massive cerebellar damage. Copyright © 2010. Published by Elsevier B.V.

  18. Gamma rays induced bold seeded high yielding mutant in chickpea

    International Nuclear Information System (INIS)

    Wani, A.A.; Anis, M.

    2001-01-01

    In pulses especially in chickpea (Cicer arietinum L.), genetic variability has been exhausted due to natural selection and hence conventional breeding methods are not very fruitful. Mutation techniques are the best methods to enlarge the genetically conditioned variability of a species within a short time and have played a significant role in the development of many crop varieties. Investigations on the effects of ionizing radiations and chemical mutagens in induction of macro-mutations have received much attention owing to their utmost importance in plant breeding. The present study reports a bold seeded mutant in chickpea, the most dominating pulse crop on the Indian subcontinent. Fresh seeds of chickpea variety 'Pusa-212' were procured from IARI, New Delhi and treated with different doses/concentrations of gamma rays ( 60 Co source at NBRI, Lucknow) and ethyl methanesulphonate (EMS), individually as well as in combination, to raise the M1 generation. Seeds of M 1 plants were sown to raise M2 plant progenies. A bold seeded mutant was isolated from 400 Gy gamma ray treatments. The mutant was confirmed as true bred, all the mutant seeds gave rise to morphologically similar plants in M 3 , which were quite distinct from the control. The bold seeded mutant showed 'gigas' characteristics and vigorous growth. The plant remained initially straight but later on attained a trailing habit due to heavy secondary branching. The leaves, petioles, flowers, pods and seeds were almost double that of the parent variety, in size. The flowering occurred 10 days later than the parent and maturity was also delayed accordingly. Observations were recorded on various quantitative traits. Plant height and number of primary branches showed a significant improvement over the parent. It is interesting to note that the number of pods and number of seeds per pod significantly decreased. However, the hundred seed weight (31.73±0.59g) in the mutant plants was more than double in the parent

  19. High yielding and disease resistant mutants of sorghum in Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Reinoso, A; Murty, B R; Taborda, F [Faculty of Agronomy, University of Zulia, Maracaibo (Venezuela)

    1987-07-01

    The programme was assisted by IAEA under project VEN/5/005 since 1978. It aims at improvement of plant type, earliness and resistance to Macrophomina in the locally adapted varieties Criollo Rojo Pequeno (CRP) and Criollo Blanco Alto (CBA). The mutagenic treatment consisted of seed irradiation at 20, 30 and 40 kR of gamma rays and chemical mutagenesis using sodium azide followed by 5000 kR gamma radiation. The 16 best mutants were evaluated in multilocation trials during M{sub 6}-M{sub 9} 1981-1984: Mutants from CRP namely 1279, 1543, 1265, 2085, 1251 and 1359 and four mutant from CBA, 109, 467, 469 and 81-1227 were found to be superior to their parents and the existing commercial hybrids. CRP 1279, 1543 and 2085 are already under large scale cultivation by farmers and under process for cultivar certification by the Ministry of Agriculture.

  20. How Life History Can Sway the Fixation Probability of Mutants

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-01-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

  1. Spatial constraints govern competition of mutant clones in human epidermis.

    Science.gov (United States)

    Lynch, M D; Lynch, C N S; Craythorne, E; Liakath-Ali, K; Mallipeddi, R; Barker, J N; Watt, F M

    2017-10-24

    Deep sequencing can detect somatic DNA mutations in tissues permitting inference of clonal relationships. This has been applied to human epidermis, where sun exposure leads to the accumulation of mutations and an increased risk of skin cancer. However, previous studies have yielded conflicting conclusions about the relative importance of positive selection and neutral drift in clonal evolution. Here, we sequenced larger areas of skin than previously, focusing on cancer-prone skin spanning five decades of life. The mutant clones identified were too large to be accounted for solely by neutral drift. Rather, using mathematical modelling and computational lattice-based simulations, we show that observed clone size distributions can be explained by a combination of neutral drift and stochastic nucleation of mutations at the boundary of expanding mutant clones that have a competitive advantage. These findings demonstrate that spatial context and cell competition cooperate to determine the fate of a mutant stem cell.

  2. Detection of DNA polymorphisms in Dendrobium Sonia White mutant lines

    International Nuclear Information System (INIS)

    Affrida Abu Hassan; Putri Noor Faizah Megat Mohd Tahir; Zaiton Ahmad; Mohd Nazir Basiran

    2006-01-01

    Dendrobium Sonia white mutant lines were obtained through gamma ray induced mutation of purple flower Dendrobium Sonia at dosage 35 Gy. Amplified Fragment Length Polymorphism (AFLP) technique was used to compare genomic variations in these mutant lines with the control. Our objectives were to detect polymorphic fragments from these mutants to provide useful information on genes involving in flower colour expression. AFLP is a PCR based DNA fingerprinting technique. It involves digestion of DNA with restriction enzymes, ligation of adapter and selective amplification using primer with one (pre-amplification) and three (selective amplification) arbitrary nucleotides. A total number of 20 primer combinations have been tested and 7 produced clear fingerprint patterns. Of these, 13 polymorphic bands have been successfully isolate and cloned. (Author)

  3. High yielding and disease resistant mutants of sorghum in Venezuela

    International Nuclear Information System (INIS)

    Reinoso, A.; Murty, B.R.; Taborda, F.

    1987-01-01

    The programme was assisted by IAEA under project VEN/5/005 since 1978. It aims at improvement of plant type, earliness and resistance to Macrophomina in the locally adapted varieties Criollo Rojo Pequeno (CRP) and Criollo Blanco Alto (CBA). The mutagenic treatment consisted of seed irradiation at 20, 30 and 40 kR of gamma rays and chemical mutagenesis using sodium azide followed by 5000 kR gamma radiation. The 16 best mutants were evaluated in multilocation trials during M 6 -M 9 1981-1984: Mutants from CRP namely 1279, 1543, 1265, 2085, 1251 and 1359 and four mutant from CBA, 109, 467, 469 and 81-1227 were found to be superior to their parents and the existing commercial hybrids. CRP 1279, 1543 and 2085 are already under large scale cultivation by farmers and under process for cultivar certification by the Ministry of Agriculture

  4. Symbiotic N fixation of several soybean varieties and mutants

    International Nuclear Information System (INIS)

    Soertini, G.; Hendratno

    1988-01-01

    Symbiotic N fixation of several soybean varieties and mutants. Research activities comprising of three experiments were carried out to screen several soybean varieties and mutants for symbiotic N fixation potential. The first two experiments involved screening of seven rhizobium strains/isolate for effective N fixation. Depending on the medium used, plant response to strains was different. In sterile medium, rhizobium strain USDA 136, 142 and TAL 102 showed a high nitrogen fixation potential. In soil only rhizobium strain USDA 110 had better performance and proved to be competitive to the native strains. Nitrogen-15 dilution method was used to screen nitrogen fixing ability of several soybean varieties and mutants. Guntur variety showed a better response to high dose of N fertilizer without disturbance in its fixing ability. This variety then was considered good to be introduced in the cropping system. (author). 8 refs

  5. Biochemical Analysis of Two Single Mutants that Give Rise to a Polymorphic G6PD A-Double Mutant

    Directory of Open Access Journals (Sweden)

    Edson Jiovany Ramírez-Nava

    2017-10-01

    Full Text Available Glucose-6-phosphate dehydrogenase (G6PD is a key regulatory enzyme that plays a crucial role in the regulation of cellular energy and redox balance. Mutations in the gene encoding G6PD cause the most common enzymopathy that drives hereditary nonspherocytic hemolytic anemia. To gain insights into the effects of mutations in G6PD enzyme efficiency, we have investigated the biochemical, kinetic, and structural changes of three clinical G6PD variants, the single mutations G6PD A+ (Asn126AspD and G6PD Nefza (Leu323Pro, and the double mutant G6PD A− (Asn126Asp + Leu323Pro. The mutants showed lower residual activity (≤50% of WT G6PD and displayed important kinetic changes. Although all Class III mutants were located in different regions of the three-dimensional structure of the enzyme and were not close to the active site, these mutants had a deleterious effect over catalytic activity and structural stability. The results indicated that the G6PD Nefza mutation was mainly responsible for the functional and structural alterations observed in the double mutant G6PD A−. Moreover, our study suggests that the G6PD Nefza and G6PD A− mutations affect enzyme functions in a similar fashion to those reported for Class I mutations.

  6. Bending patterns of chlamydomonas flagella: III. A radial spoke head deficient mutant and a central pair deficient mutant.

    Science.gov (United States)

    Brokaw, C J; Luck, D J

    1985-01-01

    Flash photomicrography at frequencies up to 300 Hz and computer-assisted image analysis have been used to obtain parameters describing the flagellar bending patterns of mutants of Chlamydomonas reinhardtii. All strains contained the uni1 mutation, to facilitate photography. The radial spoke head deficient mutant pf17, and the central pair deficient mutant, pf15, in combination with suppressor mutations that restore motility without restoring the ultrastructural or biochemical deficiencies, both generate forward mode bending patterns with increased shear amplitude and decreased asymmetry relative to the "wild-type" uni1 flagella described previously. In the reverse beating mode, the suppressed pf17 mutants generate reverse bending patterns with large shear amplitudes. Reverse beating of the suppressed pf15 mutants is rare. There is a reciprocal relationship between increased shear amplitude and decreased beat frequency, so that the velocity of sliding between flagellar microtubules is not increased by an increase in shear amplitude. The suppressor mutations alone cause decreased frequency and sliding velocity in both forward and reverse mode beating, with little change in shear amplitude or symmetry.

  7. EMS mutant spectra generated by multi-parameter flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Keysar, Stephen B. [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States); Fox, Michael H., E-mail: michael.fox@colostate.edu [Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, CO (United States); Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO (United States)

    2009-12-01

    The CHO A{sub L} cell line contains a single copy of human chromosome 11 that encodes several cell surface proteins including glycosyl phosphatidylinositol (GPI) linked CD59 and CD90, as well as CD98, CD44 and CD151 which are not GPI-linked. The flow cytometry mutation assay (FCMA) measures mutations of the CD59 gene by the absence of fluorescence when stained with antibodies against the CD59 cell surface protein. We have measured simultaneous mutations in CD59, CD44, CD90, CD98 and CD151 to generate a mutant spectrum for ionizing radiation. After treatment with ethyl methanesulfonate (EMS) many cells have an intermediate level of CD59 staining. Single cells were sorted from CD59{sup -} regions with varying levels of fluorescence and the resulting clonal populations had a stable phenotype for CD59 expression. Mutant spectra were generated by flow cytometry using the isolated clones and nearly all clones were mutated in CD59 only. Interestingly, about 60% of the CD59 negative clones were actually GPI mutants determined by staining with the GPI specific fluorescently labeled bacterial toxin aerolysin (FLAER). The GPI negative cells are most likely caused by mutations in the X-linked pigA gene important in GPI biosynthesis. Small mutations of pigA and CD59 were expected for the alkylating agent EMS and the resulting spectra are significantly different than the large deletions found when analyzing radiation mutants. After analyzing the CD59{sup -} clonal populations we have adjusted the FCMA mutant regions from 1% to 10% of the mean of the CD59 positive peak to include the majority of CD59 mutants.

  8. An early maturing rice mutant released as a variety

    International Nuclear Information System (INIS)

    Azam, M.A.; Imtiaz Uddin, Md.

    2001-01-01

    In the content of food grain production deficiency (about 1.0-1.5 million tons of rice per year according to the Bangladesh Bureau of Statistics, 1998) an induced mutation programme was undertaken in 1985. One moderate early maturing and high yielding rice mutant line (BINA6-84-4-115) has been developed by irradiating F 2 seeds of the cross 'BR4' x 'Iratom 38'. Three treatments viz., 250, 300 and 350 Gy were given to the F 2 seeds. Finally, this line was selected in M 6 generation for advanced yield trial. The line was evaluated in comparative trials with another mutant line BINA6-84-4-163. These two mutant lines had been selected earlier from 300 Gy originated lines. The two check varieties, 'BR 11' and 'BR 22' were also included in the trial, which was conducted in two consecutive T. aman seasons (July to December) during 1994 and 1995 at five locations in Bangladesh. From the results, it was evident that the mutant BINA6-84-4-115 did not differ much with the other mutant lines or check varieties in respect to plant height, number of effective tillers and panicle length but it was 10-18 days earlier than the other 3 entries. It produced a similar yield as the check BR 11 in 1994 and a higher yield than the check BR 11 and BR 22 in 1995. This mutant line gave the highest yield per day among all the entries. In addition to this, the grains are long, fine and possess a high L/B ratio, which are of high commercial value. This line has been released by the National Seed Board of Bangladesh in 1998 as a commercial variety under the name 'BINADHAN-4' for cultivation throughout Bangladesh

  9. High-Protein Soybean Mutants by Using Irradiation Technique

    International Nuclear Information System (INIS)

    Yathaputanon, C.; Kumsueb, B.; Srisombun, S.

    2009-07-01

    Full text: Soybean variety improvement for high seed protein using induced mutation was initiated. Approximately 5,000 seeds of soybean variety Chiang Mai 60 were irradiated with gamma rays at the dose of 200 Grays at Kasetsart University. High-protein seed mutants in M2 to M4 generations were selected at Nakhon Ratchasima Field Crops Research Center during 2004-2008. The Pedigree method of selection was used. Kjeldahl method was used to analyze seed protein percentages. The M2 seeds protein content of the M2 generation was 45.2% while that of the original parent was 43.0%. M3s were seeded plant to row. In each row, the best four plants were selected for protein analysis. The average protein content of selected mutant lines was 3.9% while the check variety had average protein content of 42.4%. In the M4 generation, the result showed that the average protein contents of the selected mutant lines and the check variety were 42.8% and 42.0%, respectively. In the 2007-2008 trials, four promising mutants had and average protein content of 428%, while the check variety had and average protein content of 41.1%. The four mutants produced the mean grain yield of 2.20-2.42 t/Ha, which was 10.21% higher than that of Chiang Mai 60. The mutant lines produced both a high grain protein content and a high grain yield. They will be further tested their adaptability in the research centers and farmer fields

  10. Nanoformulated cell-penetrating survivin mutant and its dual actions

    Directory of Open Access Journals (Sweden)

    Sriramoju B

    2014-07-01

    Full Text Available Bhasker Sriramoju, Rupinder K Kanwar, Jagat R Kanwar Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (NLIMBR, School of Medicine, Faculty of Health, Deakin University, Geelong, Australia Abstract: In this study, we investigated the differential actions of a dominant-negative survivin mutant (SurR9-C84A against cancerous SK-N-SH neuroblastoma cell lines and differentiated SK-N-SH neurons. In both the cases, the mutant protein displayed dual actions, where its effects were cytotoxic toward cancerous cells and proliferative toward the differentiated neurons. This can be explained by the fact that tumorous (undifferentiated SK-N-SH cells have a high endogenous survivin pool and upon treatment with mutant SuR9-C84A causes forceful survivin expression. These events significantly lowered the microtubule dynamics and stability, eventually leading to apoptosis. In the case of differentiated SK-N-SH neurons that express negligible levels of wild-type survivin, the mutant indistinguishably behaved in a wild-type fashion. It also favored cell-cycle progression, forming the chromosome-passenger complex, and stabilized the microtubule-organizing center. Therefore, mutant SurR9-C84A represents a novel therapeutic with its dual actions (cytotoxic toward tumor cells and protective and proliferative toward neuronal cells, and hence finds potential applications against a variety of neurological disorders. In this study, we also developed a novel poly(lactic-co-glycolic acid nanoparticulate formulation to surmount the hurdles associated with the delivery of SurR9-C84A, thus enhancing its effective therapeutic outcome. Keywords: survivin mutant, neurological disorders, protein therapeutics, inhibitor of apoptosis protein family, poly(lactic-co-glycolic acid

  11. RAPD analysis on male sterility mutant of Lilium asiatic hybrids 'pollyanna' induced by irradiation

    International Nuclear Information System (INIS)

    Jia Yuehui; Zhao Xiangyun; Zhang Kezhong; Huang Shangwu; Lu Changxun

    2005-01-01

    RAPD analysis of 80 random 10-mer primers on Lilium Asiatic hybrids 'pollyanna' and its 20 phenotype male sterility mutants induced by irradiation was carried out. Of the tested primers, 31 primers could produced ideal amplification bands on all materials, 4 primers generated stable different polymorphic bands among 9 mutants and 'pollyanna'. Different polymorphic bands of 7-18 were found among 9 mutants and 'pollyanna'. It was showed that 9 mutants were phenotype male sterility mutant of 'pollyanna'. (authors)

  12. Characterization of three Agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.

    OpenAIRE

    Metts, J; West, J; Doares, S H; Matthysse, A G

    1991-01-01

    Three Agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. Two of the mutants were avirulent on all hosts tested. The third mutant, Ivr-211, was a host range mutant which was avirulent on Bryophyllum diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and Daucus carota but was virulent on Zinnia elegans and Lycopersicon esculentum (tomato). That the mutant phenotype was due to the transposon insertion was d...

  13. Characterization Of Laccase T-DNA Mutants In Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Andersen, Jeppe Reitan; Asp, Torben; Mansfield, Shawn

    2009-01-01

    Laccases (P-diphenol:O2 oxidoreductase; EC 1.10.3.2), also termed laccase-like multicopper oxidases, are blue copper-containing oxidases which comprise multigene families in plants. In the Arabidopsis thaliana genome, 17 laccase genes (LAC1 to LAC17) have been annotated. To identify laccases...... for LAC15 T-DNA mutant seeds and an approximate 24 hour delay in germination was observed for these seeds. An approximate 20% reduction in glucose, galactose, and xylose was observed in primary stem cell walls of the LAC2 T-DNA mutants while similar relative increases in xylose were observed for LAC8...

  14. Mutant E. coli strain with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    2001-09-25

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  15. Mutant E. coli strain with increased succinic acid production

    Science.gov (United States)

    Donnelly, Mark; Millard, Cynthia S.; Stols, Lucy

    1998-01-01

    A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow. The invention also provides for a mutant that produces high amounts of succinic acid, which as been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

  16. Higher antibiotic yielding mutants of bacillus subtilis by gamma radiation

    International Nuclear Information System (INIS)

    Ahmad, M.S.; Shaukat, G.A.; Malik, M.A.

    1987-01-01

    When Bacillus Subtilis AECL69 was grown in malt extract-pepetone-molasses-sugar (MPMS) medium, it could produce antibiotic substance(s) with antibacterial and antifungal properties in the culture fluid. The bacterial cells grown in MPMS medium were washed and suspended into distilled water and irradiated with gamma rays in Gammacell 220 at different doses. Higher antibiotic yielding isolates (plus mutants) were obtained from cell pollutions irradiated at 15 Kr. These gamma rays-induced plus mutants showed simultaneous higher production of antibacterial as well as antifungal activity. (author)

  17. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    Science.gov (United States)

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  18. A yeast mutant specifically sensitive to bifunctional alkylation

    International Nuclear Information System (INIS)

    Ruhland, A.; Kircher, M.; Wilborn, F.; Brendel, M.

    1981-01-01

    A mutation that specifically confers sensitivity to bi- and tri-functional alkylating agents is presented. No or little cross-sensitivity to radiation or monofunctional agents could be detected. Sensitivity does not seem to be due to preferential alkylation of mutant DNA as parent and mutant strain exhibit the same amount of DNA alkylation and the same pattern of DNA lesions including interstrand crosslinks. The mutation is due to a defect in a nuclear gene which has been designated SNM1 (sensitive to nitrogen mustard); it may control an important step in the repair of DNA interstrand crosslinks (orig.(AJ)

  19. Penicillin production by mutant strains of penicillium chrysogenum

    International Nuclear Information System (INIS)

    Tawfik, Z.S.; Ashour, M.S.; Shihab, A.

    1986-01-01

    The mutagenic agent 8-rays was used to initiate the penicillium chrysogenum isolated from local spices. After irradiation, colonies invariably differing from the parent strain in their morphological and cultural characteristics were tested for antibiotic production on fermentation agar medium. Twenty two isolates were found to be penicillin producing mutant strains. Mutant strain M 24 forming small colonies with white conidia was found to be a high yielding penicillin producer (9550 i.u/ml). All of the 22 isolates obtained lost their ability to produce the antibiotic after 11 months storage at 4 0 with subsequent subculturing

  20. Study on homologous series of induced early mutants in Indica rice Ⅱ. the relationship between the homologous series of early mutants induced and the ecotype in Indica rice

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    2001-01-01

    The induced mutation in light sensitivity of the Indica rice leads to induction of the homologous series of early mutants along with the variation of ecological character and the ecoclimate. The induction of mutants was closely related to the ecotype of Indica rice, the homologous series of early mutants in different level were derived from the different ecotype of the Indica rice, otherwise, the similar homologous series of early mutants were derived from the same ecotypic variety. The induction of the early ecotypic variety derived from the homologous series of early mutants provides the basis and possibility for accelerating the development of the new cultivars. (authors)

  1. Screening of allyl alcohol resistant mutant of Rhizopus oryzae and ...

    African Journals Online (AJOL)

    Ethanol is a main by-product in the fermentation broth of Rhizopus oryzae during the production of high-optical purity L-lactic acid. By screening the lower activity of alcohol dehydrogenase (ADH) mutant, thus decreasing the flux of pyruvic acid to ethanol may be a virtual method for increasing the conversion rate of glucose ...

  2. UV- and gamma-radiation sensitive mutants of Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Jiang, C.Z.; Yen, C.N.; Cronin, K.; Mitchell, D.; Britt, A.B.

    1997-01-01

    Arabidopsis seedlings repair UV-induced DNA damage via light-dependent and -independent pathways. The mechanism of the ''dark repair'' pathway is still unknown. To determine the number of genes required for dark repair and to investigate the substrate-specificity of this process we isolated mutants with enhanced sensitivity to UV radiation in the absence of photoreactivating light. Seven independently derived UV sensitive mutants were isolated from an EMS-mutagenized population. These fell into six complementation groups, two of which (UVR1 and UVH1) have previously been defined. Four of these mutants are defective in the dark repair of UV-induced pyrimidine [6-4] pyrimidinone dimers. These four mutant lines are sensitive to the growth-inhibitory effects of gamma radiation, suggesting that this repair pathway is also involved in the repair of some type of gamma-induced DNA damage product. The requirement for the coordinate action of several different gene products for effective repair of pyrimidine dimers, as well as the nonspecific nature of the repair activity, is consistent with nucleotide excision repair mechanisms previously described in Saccharomyces cerevisiae and nonplant higher eukaryotes and inconsistent with substrate-specific base excision repair mechanisms found in some bacteria, bacteriophage, and fungi. (author)

  3. 'CM 88' - A multiple disease resistant chickpea mutant variety

    International Nuclear Information System (INIS)

    Haq, M.A.; Hassan, Mahmudul; Sadiq, M.

    2001-01-01

    Full text: Chickpea is the most important grain legume crop of Pakistan. Ascochyta blight (Ascochyta rabiei) and Fusarium wilt (Fusarium oxysporum F. sp cicer) are most serious diseases, having the potential to devastate a crop. A multiple disease resistant and high yielding mutant CM 88 has been developed through 100 Gy gamma irradiation treatment of variety 'C 727'. This was once a widely grown and popular variety, which lost its resistance to Ascochyta and was replaced. The selection of mutants was performed in the M2 generation grown in the Ascochyta blight nursery and sixteen mutants were selected. In the subsequent generations CM 88 proved resistant to both Ascochyta blight and Fusarium wilt, and exhibited superiority in agronomic characteristics. CM 88 was also tested for many years in the various yield trials on research stations and farmers fields throughout the country. In these trials it out yielded both the parent and standard varieties. The mutant CM 88 has been approved by the Punjab Seed Council on 27 October 1994 for general cultivation in the Punjab Province, especially the Thal area which accounts for more than 70% of the area under chickpea cultivation. (author)

  4. Plants Regeneration Derived From Various on Peanut on Mutant Lines

    International Nuclear Information System (INIS)

    Dewi, Kumala; Masrizal; Mugiono

    1998-01-01

    The study of calli, greenspot formation and shoot regeneration on peanut mutant lines has ben conducted by MS media. Three explants derived from shoot tips, embryo and seeding root of two mutant lines a/20/3 and D/25/3/2 were used in this experiment. the explants were cultured on modified MS media enriched by vitamins, growth regulation, amino acids for fourth teen calli were transferred on regeneration media. The ability of calli formation and plant regeneration of each explant and genotypes of plants was varied. Greenspot and shoot formation were observed seventh days after the calli transferred on regeneration media. It is shown that the ability of calli, greenspot and shoot formation of each explants and genotypes was varied. the high ability of calli, greenspot and shoot formation were found in explant derived from shoot tip and embryo. Seedling root explant has lower ability in calli formation, while greenspot and shoot was formatted. The ability of calli, greenspot and shoot formation on A/20/3 mutant line was better than D/25/3/2 mutant line. (author)

  5. Estimates of selection parameters in protein mutants of spring barley

    International Nuclear Information System (INIS)

    Gaul, H.; Walther, H.; Seibold, K.H.; Brunner, H.; Mikaelsen, K.

    1976-01-01

    Detailed studies have been made with induced protein mutants regarding a possible genetic advance in selection including the estimation of the genetic variation and heritability coefficients. Estimates were obtained for protein content and protein yield. The variation of mutant lines in different environments was found to be many times as large as the variation of the line means. The detection of improved protein mutants seems therefore possible only in trials with more than one environment. The heritability of protein content and protein yield was estimated in different sets of environments and was found to be low. However, higher values were found with an increasing number of environments. At least four environments seem to be necessary to obtain reliable heritability estimates. The geneticall component of the variation between lines was significant for protein content in all environmental combinations. For protein yield some environmental combinations only showed significant differences. The expected genetic advance with one selection step was small for both protein traits. Genetically significant differences between protein micromutants give, however, a first indication that selection among protein mutants with small differences seems also possible. (author)

  6. Forward genetic screen for auxin-deficient mutants by cytokinin

    Czech Academy of Sciences Publication Activity Database

    Wu, L.; Luo, P.; Di, D.W.; Wang, L.; Wang, M.; Lu, C.K.; Wei, S.D.; Zhang, L.; Zhang, T.Z.; Amakorová, Petra; Strnad, Miroslav; Novák, Ondřej; Guo, G.Q.

    2015-01-01

    Roč. 5, JUL 6 (2015) ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : ETHYLENE-INSENSITIVE MUTANTS * YUCCA FLAVIN MONOOXYGENASES * ARABIDOPSIS-THALIANA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.228, year: 2015

  7. p21-ras effector domain mutants constructed by "cassette" mutagenesis

    DEFF Research Database (Denmark)

    Stone, J C; Vass, W C; Willumsen, B M

    1988-01-01

    A series of mutations encoding single-amino-acid substitutions within the v-rasH effector domain were constructed, and the ability of the mutants to induce focal transformation of NIH 3T3 cells was studied. The mutations, which spanned codons 32 to 40, were made by a "cassette" mutagenesis...

  8. Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila

    Indian Academy of Sciences (India)

    2014-07-20

    Ohtomo et al. .... stand the influence of these two phases, short sampling segments were ... per-long (perL) mutants also showed ultradian rhythms un- der L:L ..... would like to dedicate this paper to the memory of Dr Obaid. Siddiqi.

  9. Disturbed secretion of mutant adiponectin associated with the metabolic syndrome.

    Science.gov (United States)

    Kishida, Ken; Nagaretani, Hiroyuki; Kondo, Hidehiko; Kobayashi, Hideki; Tanaka, Sachiyo; Maeda, Norikazu; Nagasawa, Azumi; Hibuse, Toshiyuki; Ohashi, Koji; Kumada, Masahiro; Nishizawa, Hitoshi; Okamoto, Yoshihisa; Ouchi, Noriyuki; Maeda, Kazuhisa; Kihara, Shinji; Funahashi, Tohru; Matsuzawa, Yuji

    2003-06-20

    Adiponectin, an adipocyte-derived protein, consists of collagen-like fibrous and complement C1q-like globular domains, and circulates in human plasma in a multimeric form. The protein exhibits anti-diabetic and anti-atherogenic activities. However, adiponectin plasma concentrations are low in obese subjects, and hypoadiponectinemia is associated with the metabolic syndrome, which is a cluster of insulin resistance, type 2 diabetes mellitus, hypertension, and dyslipidemia. We have recently reported a missense mutation in the adiponectin gene, in which isoleucine at position 164 in the globular domain is substituted with threonine (I164T). Subjects with this mutation showed markedly low level of plasma adiponectin and clinical features of the metabolic syndrome. Here, we examined the molecular characteristics of the mutant protein associated with a genetic cause of hypoadiponectinemia. The current study revealed (1) the mutant protein showed an oligomerization state similar to the wild-type as determined by gel filtration chromatography and, (2) the mutant protein exhibited normal insulin-sensitizing activity, but (3) pulse-chase study showed abnormal secretion of the mutant protein from adipose tissues. Our results suggest that I164T mutation is associated with hypoadiponectinemia through disturbed secretion into plasma, which may contribute to the development of the metabolic syndrome.

  10. Semi-dwarf mutant lines of hexaploid triticale

    International Nuclear Information System (INIS)

    Pidra, M.

    1989-01-01

    A spring form of hexaploid secondary triticale ADD 143/71, bred by MOGILEVA at the Plant Breeding Station at Uhretice was used for the mutagen treatment. The mutation experiment started in 1979. Seeds were treated with a 0.8 mM water solution of N-methyl-N-nitrosourea (MNH) (CETL and RELICHOVA, unpublished). From 180 M 1 plants, one spike was harvested per plant. A random sample of these seeds was sown as M 2 in 1980 and several plants with shorter main culm were selected. Selfed progenies of eight mutant plants designated ADD 143-m1, ADD 143-m2, ADD 143-m3 etc. were further tested in M 3 and M 4 . There were significant differences in culm length and in some other characters between the original line and the mutant lines. Especially the line m8 looks like a promising source of semi-dwarfness for breeding programmes of hexaploid triticale. During 1985-1987 genetic analysis was performed on the ADD 143/71 and the mutant lines m2, m6, m7 and m8, which suggest that their mutant genes are allelic and recessive

  11. Enhanced longevity in tau mutant Syrian hamsters, Mesocricetus auratus

    NARCIS (Netherlands)

    Oklejewicz, Malgorzata; Daan, Serge

    The single-gene mutation tau in the Syrian hamster shortens the circadian period by about 20% in the homozygous mutant and simultaneously increases the mass-specific metabolic rate by about 20%. Both effects might be expected to lead to a change in longevity. To test such expectations, the life span

  12. Evaluation on selected dwarf and semidwarf mutants of upland rice

    International Nuclear Information System (INIS)

    Riyanti Sumanggono, A.M.

    1984-01-01

    Seratus malam local upland rice variety was irradiated with gamma-rays at doses of O.1, 0.2, 0.3, 0.4 and 0.5 kGy. Observation of radiation effect was carried out on root and shoot length of M 1 seedlings; plant height, panicle length and number of tiller and seed sterility in M 1 plants. Selection for dwarf and semi-dwarf characteristics were done in M 2 plants, and selected again in M 3 . Observation on radiation effect indicated that 'Seratus Malam' seems to be more resistant than the lowland rice varieties. Increasing doses of radiation caused increasing frequency of chlorophyll mutations as well as chlorophyll mutants. Whereas, selection of dwarf or semi-dwarf in M 2 plants seems that mutant and mutation frequencies decreased as the dose increased. Dose of 0.2 kGy was suitable for selection of dwarf or semi-dwarf plants. Plant height could be influenced by environmental condition. Many of the selected M 2 plants were not really dwarf or semi-dwarf mutants. M 3 evaluation of the selected M 2 plants was really beneficial in the mutant selection. (author)

  13. clustering common bean mutants based on heterotic groupings

    African Journals Online (AJOL)

    ACSS

    2015-02-19

    Feb 19, 2015 ... Blair, W.M., Porch, T., Cichy, K., Galeano, H. C,. Lariguet, P., Pankhurst, C. and Broughton, W. 2007a. Induced mutants in common bean. (Phaseolus vulgaris) and their potential use in nutrition quality, breeding and gene discovery. Israel Journal of Plant Sciences. 55:191 - 200. Blair, W.M., Fregene, A.M., ...

  14. Officially released mutant varieties - the FAO/IAEA Database

    International Nuclear Information System (INIS)

    Maluszynski, M.; Nichterlein, K.; Zanten, L. van; Ahloowalia, B.S.

    2000-01-01

    In the approximately 70 year-old history of induced mutations, there are many examples on the development of new and valuable alteration in plant characters significantly contributing to increased yield potential of specific crops. However, knowledge on the success of induced mutations in crop improvement among geneticists and breeders is usually limited to species of their interest. The present paper contains a comprehensive list of officially released mutant varieties, based on information from plant breeders. The number of mutant varieties officially released and recorded in the FAO/IAEA Mutant Varieties Database before the end of 2000 is 2,252. Almost half of these varieties have been released during the last 15 years. Considering a significant delay in the dissemination of information on newly released varieties and difficulties in the collection of such data, there has been a renaissance in the use of mutation techniques in crop improvement. At the demand of geneticists, plant breeders, and more recently molecular geneticists, for information on released mutant varieties of specific crops, the MVD was transferred to the web site of the FAO/IAEA Joint Division. The MVD will be available on our web pages early in 2001. (author)

  15. Genomic diversity among Basmati rice ( Oryza sativa L) mutants ...

    African Journals Online (AJOL)

    Mutation breeding can be considered successful in obtaining new cultivars and broadening the genetic base of rice crop. In order to obtain new varieties of rice with improved agronomic and grain characteristics, gamma radiation (60Co) has been used to generate novel mutants of the Basmati rice. In this study rice cultivars ...

  16. Kinetics of formation of induced mutants of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Chepurnoj, A.I.; Levkovich, N.V.; Mikhova-Tsenova, N.; Mel'nikova, L.A.

    1990-01-01

    UV and γ-radiation mutagenic effect an various strains of Saccharomyces cerevisiae was studied by analyzing formation kinetics of induced mutants at the period of postirradiation incubation. Mechanisms of induced reverse formation was suggested. The presented analysis is considered to be differential taking account of more subtle aspects of induced mutagenesis. 8 refs.; 10 figs.; 3 tabs

  17. Proteostasis and ageing: insights from long-lived mutant mice.

    Science.gov (United States)

    Sands, William A; Page, Melissa M; Selman, Colin

    2017-10-15

    The global increase in life expectancy is creating significant medical, social and economic challenges to current and future generations. Consequently, there is a need to identify the fundamental mechanisms underlying the ageing process. This knowledge should help develop realistic interventions capable of combatting age-related disease, and thus improving late-life health and vitality. While several mechanisms have been proposed as conserved lifespan determinants, the loss of proteostasis - where proteostasis is defined here as the maintenance of the proteome - appears highly relevant to both ageing and disease. Several studies have shown that multiple proteostatic mechanisms, including the endoplasmic reticulum (ER)-induced unfolded protein response (UPR), the ubiquitin-proteasome system (UPS) and autophagy, appear indispensable for longevity in many long-lived invertebrate mutants. Similarly, interspecific comparisons suggest that proteostasis may be an important lifespan determinant in vertebrates. Over the last 20 years a number of long-lived mouse mutants have been described, many of which carry single-gene mutations within the growth-hormone, insulin/IGF-1 or mTOR signalling pathways. However, we still do not know how these mutations act mechanistically to increase lifespan and healthspan, and accordingly whether mechanistic commonality occurs between different mutants. Recent evidence supports the premise that the successful maintenance of the proteome during ageing may be linked to the increased lifespan and healthspan of long-lived mouse mutants. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

  18. Siim Nestor soovitab : Mutant Disco. Azymuth. Klubis Hollywood / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2003-01-01

    Mutant Disco klubis Prive 4. juulil. Brasiilia jazz-trio Azmuth klubis BonBon 5. juulil. Pidustuste sarja Hip Hop Cafe sünnipäeva tähistamisest klubis Hollywood 4. juulil, üritusest Ibiza Night 5. juulil

  19. Complementation of sweet corn mutants: a method for grouping ...

    Indian Academy of Sciences (India)

    for sweet corn are now expanding and the demands are increasing due to ... tropical/tropical regions of India is amongst one of the factors ... Maize endosperm mutant genes that affect quality of sweet corn can ... Thus, the concept of comple-.

  20. Genetic identification of a dwarf mutant in cucumber ( Cucumis ...

    African Journals Online (AJOL)

    The dwarf (compact) plant architecture is an important trait in cucumber (Cucumis sativus L.) breeding. A dwarf type mutant was selected from the cucumbers. The morphological and reproductive characteristics of the dwarf were compared with the vine plants. The dwarf type of cucumbers is characterized by its short ...

  1. Functional analysis of mutant human carnitine acylcarnitine translocases in yeast

    NARCIS (Netherlands)

    IJlst, L.; van Roermund, C. W.; Iacobazzi, V.; Oostheim, W.; Ruiter, J. P.; Williams, J. C.; Palmieri, F.; Wanders, R. J.

    2001-01-01

    Long chain fatty acids are translocated as carnitine esters across the mitochondrial inner membrane by carnitine acylcarnitine translocase (CACT). We report functional studies on the mutant CACT proteins from a severe and a mild patient with CACT deficiency. CACT activities in fibroblasts of both

  2. Mutants of Aspergillus nidulans affected in asexual development

    Indian Academy of Sciences (India)

    A. nidulans mutants by inducing base transitions and transversions ... tone 2, yeast extract 2, hydrolysed casein 1, and (in /g/l) in- ositol 4000, choline .... carbon sources; flu, fluffy mutation; uvsH, sensitivity to UV radiation. Gene symbols ...

  3. Mahalanobis distance screening of Arabidopsis mutants with chlorophyll fluorescence

    Czech Academy of Sciences Publication Activity Database

    Codrea, C. C.; Hakala-Yatkin, M.; Karlund-Marttila, A.; Nedbal, Ladislav; Aittokallio, T.; Nevalainen, O. S.; Tyystjärvi, E.

    2010-01-01

    Roč. 105, č. 3 (2010), s. 273-283 ISSN 0166-8595 Institutional research plan: CEZ:AV0Z60870520 Keywords : arabidopsis thaliana * chlorophyll fluorescence * fluorescence imaging * mutant detection * outlier detection Subject RIV: EH - Ecology, Behaviour Impact factor: 2.410, year: 2010 http://www.springerlink.com/content/x3586512462pn006/

  4. Potential of multiseeded mutant (msd) to boost sorghum grain yield

    Science.gov (United States)

    Seed number per plant is an important determinant of the grain yield in cereal and other crops. We have isolated a class of multiseeded (msd) sorghum (Sorghum bicolor L. Moench) mutants that are capable of producing three times the seed number and twice the seed weight per panicle as compared with t...

  5. Genetic characterization of glossy-leafed mutant broccoli lines

    Science.gov (United States)

    Glossy mutants of Brassica oleracea L. have reduced or altered epicuticular wax on the surface of their leaves as compared to wild-type plants, conveying a shiny green appearance. Mutations conferring glossiness are common and have been found in most B. oleracea crop varieties, including cauliflower...

  6. Forward and reverse genetics: The LORE1 retrotransposon insertion mutants

    DEFF Research Database (Denmark)

    Fukai, Eigo; Malolepszy, Anna; Sandal, Niels Nørgaard

    2014-01-01

    The endogenous Lotus retrotransposon 1 (LORE1) transposes in the germ line of Lotus japonicus plants that carry an active element. This feature of LORE1 has been exploited for generation of a large non-transgenic insertion mutant population, where insertions have been annotated using next-generat...

  7. Development and evaluation of drought resistant mutant germ ...

    African Journals Online (AJOL)

    Seed from M2 to M5 generations (M = mutant) were used in the study. The M2 to M4 ... facing food insecurity, such as Africa, peasants or small-scale farmers have .... sandy soil removed by washing and the root system examined. A nail board ...

  8. Structural basis for hyperactivity of cN-II mutants

    Czech Academy of Sciences Publication Activity Database

    Hnízda, Aleš; Škerlová, Jana; Šinalová, Martina; Pachl, Petr; Man, Petr; Novák, Petr; Fábry, Milan; Řezáčová, Pavlína; Veverka, Václav

    2015-01-01

    Roč. 22, č. 1 (2015), s. 4 ISSN 1211-5894. [Discussions in Structural Molecular Biology. Annual Meeting of the Czech Society for Structural Biology /13./. 19.03.2015-21.03.2015, Nové Hrady] Institutional support: RVO:61388963 ; RVO:68378050 ; RVO:61388971 Keywords : cN-II mutants * enzyme hyperactivity Subject RIV: CE - Biochemistry

  9. Inducement and identification of an endosperm mutant in maize

    African Journals Online (AJOL)

    ajl yemi

    2011-11-30

    Nov 30, 2011 ... Drummond EP, Ausubel FM (2000). Three unique mutants of. Arabidopsis identify eds loci required for limiting growth of a biotrophic fungal pathogen. Plant J. 24(2): 205-218. Dinges JR, Colleoni C, Myers AM, James MG (2001). Molecular structure of three mutations at the maize sugary1 locus and their.

  10. Abnormal grooming activity in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Strazielle, C; Lefevre, A; Jacquelin, C; Lalonde, R

    2012-07-15

    Dab1(scm) mutant mice, characterized by cell ectopias and degeneration in cerebellum, hippocampus, and neocortex, were compared to non-ataxic controls for different facets of grooming caused by brief water immersions, as well as some non-grooming behaviors. Dab1(scm) mutants were strongly affected in their quantitative functional parameters, exhibiting higher starting latencies before grooming relative to non-ataxic littermates of the A/A strain, fewer grooming bouts, and grooming components of shorter duration, with an unequal regional distribution targeting almost totally the rostral part (head washing and forelimb licking) of the animal. Only bouts of a single grooming element were preserved. The cephalocaudal order of grooming elements appeared less disorganized, mutant and control mice initiating the grooming with head washing and forelimb licking prior to licking posterior parts. However, mutants differed from controls in that all their bouts were incomplete but uninterrupted, although intergroup difference for percentage of the incorrect transitions was not significant. In contrast to grooming, Dab1(scm) mice ambulated for a longer time. During walking episodes, they exhibited more body scratching than controls, possibly to compensate for the lack of licking different body parts. In conjunction with studies with other ataxic mice, these results indicate that the cerebellar cortex affects grooming activity and is consequently involved in executing various components, but not in its sequential organization, which requires other brain regions such as cerebral cortices or basal ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Analysis of Lysophospholipid Content in Low Phytate Rice Mutants.

    Science.gov (United States)

    Tong, Chuan; Chen, Yaling; Tan, Yuanyuan; Liu, Lei; Waters, Daniel L E; Rose, Terry J; Shu, Qingyao; Bao, Jinsong

    2017-07-05

    As a fundamental component of nucleic acids, phospholipids, and adenosine triphosphate, phosphorus (P) is critical to all life forms, however, the molecular mechanism of P translocation and distribution in rice grains are still not understood. Here, with the use of five different low phytic acid (lpa) rice mutants, the redistribution in the main P-containing compounds in rice grain, phytic acid (PA), lysophospholipid (LPL), and inorganic P (Pi), was investigated. The lpa mutants showed a significant decrease in PA and phytate-phosphorus (PA-P) concentration with a concomitant increase in Pi concentration. Moreover, defects in the OsST and OsMIK genes result in a great reduction of specific LPL components and LPL-phosphorus (LPL-P) contents in rice grain. In contrast, defective OsMRP5 and Os2-PGK genes led to a significant increase in individual LPL components. The effect of the Os2-PGK gene on the LPL accumulation was validated using breeding lines derived from a cross between KBNT-lpa (Os2-PGK mutation) and Jiahe218. This study demonstrates that these rice lpa mutants lead to the redistribution of Pi in endosperm and modify LPL biosynthesis. Increase LPLs in the endosperm in the lpa mutants may have practical applications in rice breeding to produce "healthier" rice.

  12. Mutant of Japanese pear resistant to Black Spot Disease

    International Nuclear Information System (INIS)

    Sanada, T.; Nishida, T.; Ikeda, F.

    1987-01-01

    Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

  13. Isolation and characterization of MMS-sensitive mutants of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Prakash, L.; Prakash, S.

    1977-01-01

    We have isolated mutants sensitive to methyl methanesulfonate (MMS) in Saccharomyces cerevisiae. Alleles of rad1, rad4, rad6, rad52, rad55 and rad57 were found among these mms mutants. Twenty-nine of the mms mutants which complement the existing radiation-sensitive (rad and rev) mutants belong to 22 new complementation groups. Mutants from five complementation groups are sensitive only to MMS. Mutants of 11 complementation groups are sensitive to uv or x rays in addition to MMS, mutants of six complementation groups are sensitive to all three agents. The cross-sensitivities of these mms mutants to uv and x rays are discussed in terms of their possible involvement in DNA repair. Sporulation is reduced or absent in homozygous diploids of mms mutants from nine complementation groups

  14. Identification of a novel ga-related bush mutant in pumpkin (cucurbita moschata duchesne)

    International Nuclear Information System (INIS)

    Wu, T.; Cao, J.

    2015-01-01

    Pumpkin (Cucurbita moschata Duchesne) bush mutant plants were characterized by short stems. The sensitivity of pumpkin bush mutant plants to exogenous hormones was identified in this study. Results revealed that internode elongation of bush mutant plants could respond to gibberellins (GA4+7 and GA3), but not to indole acetic acid (IAA) and brassinosteroids (BR); by contrast, the mutant phenotype of bush mutant plants could not be fully rescued by GA4+7 and GA3. The internode of bush mutant plants yielded a lower KS expression level than that of vine plants. Therefore, pumpkin bush mutant plants were designated as GA-related mutant plants eliciting a partial response to GAs; the action of IAA and BR might not be involved in the internode growth of pumpkin bush mutant plants, specifically Cucurbita moschata Duch. (author)

  15. Identification of some Rice Mutants using Morphological and Molecular Methods

    International Nuclear Information System (INIS)

    Sobieh, S.E.S.

    2006-01-01

    This investigation was conducted at the experimental farm of plant research department, nuclear research center, atomic energy authority, abu zaabal in order to verify four rice genotypes i.e sakha 102, giza 178, high yielding mutant (Ms 6) and high yielding mutant (MG 16). the (UPOV) rice descriptor was used to identify the germplasm morphologically .Molecular RAPD-PCR was used to identify genetic variability on the molecular level for the tested genotypes. 1- the results indicated that according to (UPOV) rice descriptor eight morphological traits were completely different between mutant Ms 6 in comparison with the parent sakha 102 and mut. MG 16 in comparison parent giza 178, the traits were ; stem thickness, stem length, panicle length, 1000-grain weight, grain length, grain width decorticated grain length and decorticated grain width. 2- using 10 arbitrary primers, through four rice genotypes on the molecular level using RAPD markers. the size of the amplified fragments were ranged from 0.201 to 2.036 k bp. two primers OPB-13 and OPB-16 showed no polymorphism among genotypes tested. 3- the total number of amplicons produced by the 8 polymorphic RAPD profiels was 66. the total number of monomorphic amplicons was 32. however, the total number of polymorphic amplicons was 34. 4- the percentage of polymorphism ranged from (22.22%) for primer OPA-18 to (90%) for primer OPB-11. 5-the highest genetic similarity (90.3%) was between sakha 102 and high yielding mut. (Ms 6). the genetic similarity (75.5%) was between giza 178 and high yielding mut.(MG 16). 6- one positive unique marker amplified by OPA-18 Primer identified the high yielding mutant Ms 6 but three positive unique markers amplified by OPB-17 primer and OPA-18 primer identified the high yielding mutant MG 16

  16. Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats.

    Science.gov (United States)

    Atta, Hussein; El-Rehany, Mahmoud; Roeb, Elke; Abdel-Ghany, Hend; Ramzy, Maggie; Gaber, Shereen

    2016-02-01

    Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats. Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment. Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64). Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  17. Human GLTP and mutant forms of ACD11 suppress cell death in the Arabidopsis acd11 mutant

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; McKinney, Lea V; Pike, Helen

    2008-01-01

    The Arabidopsis acd11 mutant exhibits runaway, programmed cell death due to the loss of a putative sphingosine transfer protein (ACD11) with homology to mammalian GLTP. We demonstrate that transgenic expression in Arabidopsis thaliana of human GLTP partially suppressed the phenotype of the acd11...

  18. PedonnanceofE3rly MatUring MutantS Derived from ''SuPa'~ Rice ...

    African Journals Online (AJOL)

    Vienna, Austria in 1994. The dry seeds were in-adiated with gamma rays using three doses (170, 210. --iifid 24OC;Y).frOm C.obalt 60 (lCO) in order shorten the plant height and maturity period. From the resulting mutant. PoPulations ortgindtiriifroni modified single seed descent method, five Jery early maturing lines plus the ...

  19. Analysis of Mycobacterium avium subsp. paratuberculosis mutant libraries reveals loci-dependent transcription biases and strategies to novel mutant discovery

    Science.gov (United States)

    Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of Johne’s disease in ruminants and it has been implicated as a cause of Crohn’s disease in humans. The generation of comprehensive random mutant banks by transposon mutagenesis is a fundamental wide genomic technology utilized...

  20. Selection and agronomic evaluation of induced mutant lines of sesame

    International Nuclear Information System (INIS)

    Hoballah, A.A.

    2001-01-01

    Station yield trial: Three high yielding mutants (8, 48, and EFM92) with better and stable performance were developed in our breeding programme and submitted for registration to the Agricultural Research Center (ARC), Egyptian Ministry of Agriculture and Land Reclamation. Multi-location yield trials indicated that mutant line EFM92 ranked first in all locations; significant yield increases recorded for it ranged from 14.7 to 74.0% over the check variety. Moreover, it was 15-20 days earlier than the check and/or other mutants. Mutant lines 8 and 48 produced higher seed yields than the check at two different locations. These mutants can probably be grown and produce more yield than the check variety at the low yielding environments. Seed quality assay: During 1996 and 1997, 15 promising lines of sesame including mutants and hybrid populations as well as the local variety were evaluated for seed protein, oil content and fatty acid composition. The protein content varied from 20.6 to 26.7%; hybrid population EXM90 gave the highest value. About 85% of the total fatty acids in the oil are unsaturated (oleic and linoleic) and 15% saturated, mainly palmitic and stearic. Linoleic acid ranged from 41.8 to 47.9%. Mutant lines 6, 9, and EFM92, which gave high oil content (54-55.5%) together with high linoleic acid values (45.2-47.8%), are recommended for breeding for seed oil quality. Heterosis, combining ability and type of gene action in sesame: A half diallel set of crosses involving seven parents was used to study heterosis and combining ability in the F 1 generation as well as the nature of gene action controlling seed yield and its contributing traits in both F 1 and F 2 in order to identify the most efficient breeding methods leading to rapid genetic improvement. The expressions of heterosis varied with the crosses and characters investigated. The maximal significant positive useful heterosis was observed for branches/plant (52.9%) followed by seed yield/plant (38

  1. Enhancement of yellow pigment production by intraspecific protoplast fusion of Monascus spp. yellow mutant (ade(-)) and white mutant (prototroph).

    Science.gov (United States)

    Klinsupa, Worawan; Phansiri, Salak; Thongpradis, Panida; Yongsmith, Busaba; Pothiratana, Chetsada

    2016-01-10

    To breed industrially useful strains of a slow-growing, yellow pigment producing strain of Monascus sp., protoplasts of Monascus purpureus yellow mutant (ade(-)) and rapid-growing M. purpureus white mutant (prototroph) were fused and fusants were selected on minimal medium (MM). Preliminary conventional protoplast fusion of the two strains was performed and the result showed that only white colonies were detected on MM. It was not able to differentiate the fusants from the white parental prototroph. To solve this problem, the white parental prototroph was thus pretreated with 20mM iodoacetamide (IOA) for cytoplasm inactivation and subsequently taken into protoplast fusion with slow-growing Monascus yellow mutant. Under this development technique, only the fusants, with viable cytoplasm from Monascus yellow mutant (ade(-)), could thus grow on MM, whereas neither IOA pretreated white parental prototroph nor yellow auxotroph (ade(-)) could survive. Fifty-three fusants isolated from yellow colonies obtained through this developed technique were subsequently inoculated on complete medium (MY agar). Fifteen distinguished yellow colonies from their parental yellow mutant were then selected for biochemical, morphological and fermentative properties in cassava starch and soybean flour (SS) broth. Finally, three most stable fusants (F7, F10 and F43) were then selected and compared in rice solid culture. Enhancement of yellow pigment production over the parental yellow auxotroph was found in F7 and F10, while enhanced glucoamylase activity was found in F43. The formation of fusants was further confirmed by monacolin K content, which was intermediate between the two parents (monacolin K-producing yellow auxotroph and non-monacolin K producing white prototroph). Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Mutants of GABA transaminase (POP2 suppress the severe phenotype of succinic semialdehyde dehydrogenase (ssadh mutants in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Frank Ludewig

    Full Text Available BACKGROUND: The gamma-aminubutyrate (GABA shunt bypasses two steps of the tricarboxylic acid cycle, and is present in both prokaryotes and eukaryotes. In plants, the pathway is composed of the calcium/calmodulin-regulated cytosolic enzyme glutamate decarboxylase (GAD, the mitochondrial enzymes GABA transaminase (GABA-T; POP2 and succinic semialdehyde dehydrogenase (SSADH. We have previously shown that compromising the function of the GABA-shunt, by disrupting the SSADH gene of Arabidopsis, causes enhanced accumulation of reactive oxygen intermediates (ROIs and cell death in response to light and heat stress. However, to date, genetic investigations of the relationships between enzymes of the GABA shunt have not been reported. PRINCIPAL FINDINGS: To elucidate the role of succinic semialdehyde (SSA, gamma-hydroxybutyrate (GHB and GABA in the accumulation of ROIs, we combined two genetic approaches to suppress the severe phenotype of ssadh mutants. Analysis of double pop2 ssadh mutants revealed that pop2 is epistatic to ssadh. Moreover, we isolated EMS-generated mutants suppressing the phenotype of ssadh revealing two new pop2 alleles. By measuring thermoluminescence at high temperature, the peroxide contents of ssadh and pop2 mutants were evaluated, showing that only ssadh plants accumulate peroxides. In addition, pop2 ssadh seedlings are more sensitive to exogenous SSA or GHB relative to wild type, because GHB and/or SSA accumulate in these plants. SIGNIFICANCE: We conclude that the lack of supply of succinate and NADH to the TCA cycle is not responsible for the oxidative stress and growth retardations of ssadh mutants. Rather, we suggest that the accumulation of SSA, GHB, or both, produced downstream of the GABA-T transamination step, is toxic to the plants, resulting in high ROI levels and impaired development.

  3. A sorghum (Sorghum bicolor mutant with altered carbon isotope ratio.

    Directory of Open Access Journals (Sweden)

    Govinda Rizal

    Full Text Available Recent efforts to engineer C4 photosynthetic traits into C3 plants such as rice demand an understanding of the genetic elements that enable C4 plants to outperform C3 plants. As a part of the C4 Rice Consortium's efforts to identify genes needed to support C4 photosynthesis, EMS mutagenized sorghum populations were generated and screened to identify genes that cause a loss of C4 function. Stable carbon isotope ratio (δ13C of leaf dry matter has been used to distinguishspecies with C3 and C4 photosynthetic pathways. Here, we report the identification of a sorghum (Sorghum bicolor mutant with a low δ13C characteristic. A mutant (named Mut33 with a pale phenotype and stunted growth was identified from an EMS treated sorghum M2 population. The stable carbon isotope analysis of the mutants showed a decrease of 13C uptake capacity. The noise of random mutation was reduced by crossing the mutant and its wildtype (WT. The back-cross (BC1F1 progenies were like the WT parent in terms of 13C values and plant phenotypes. All the BC1F2 plants with low δ13C died before they produced their 6th leaf. Gas exchange measurements of the low δ13C sorghum mutants showed a higher CO2 compensation point (25.24 μmol CO2.mol-1air and the maximum rate of photosynthesis was less than 5μmol.m-2.s-1. To identify the genetic determinant of this trait, four DNA pools were isolated; two each from normal and low δ13C BC1F2 mutant plants. These were sequenced using an Illumina platform. Comparison of allele frequency of the single nucleotide polymorphisms (SNPs between the pools with contrasting phenotype showed that a locus in Chromosome 10 between 57,941,104 and 59,985,708 bps had an allele frequency of 1. There were 211 mutations and 37 genes in the locus, out of which mutations in 9 genes showed non-synonymous changes. This finding is expected to contribute to future research on the identification of the causal factor differentiating C4 from C3 species that can be used

  4. A high yielding, better quality chickpea mutant variety 'NIFA-95'

    International Nuclear Information System (INIS)

    Hassan, S.; Javed, M.A.; Khattak, S.U.K.; Iqbal, M.M.

    2001-01-01

    Chickpea or gram (Cicer arietinum L.) is an important legume crop of Pakistan, grown on over one million hectares annually. The national average yield of the crop is very low (0.5 t/ha) and thus the country had to spent about 2 billion rupees ($ 50 million) on import of pulses. The main causes of low yield are non-availability of genetic sources for resistance to various diseases especially gram blight Ascochyta rabiei (Pass.) Lab., insect pest (Pod borer) and non-adoption of proper production technology by the farmers. This calls for earnest efforts of breeders to evolve high yielding and disease resistant varieties of chickpea for provision of quality seeds to the farming community to increase production of this important crop. Seeds of a highly blight susceptible variety '6153' were irradiated at 200 Gy dose of gamma radiation in 1985 and the promising mutant line CMN-446-4 was selected in M3 generation on the basis of disease resistance, greater number of pods and better plant type. After confirmation of its resistance to blight in M 4 and M 5 , the mutant line was evaluated in various trials at different locations. In the advanced and zonal yield trials during 1993-95, the line CMN-446-4 produced the highest grain yield of 2,600 kg/ha as compared to the rest of the mutants and varieties. The line was also evaluated in the chickpea national uniform yield trial, conducted on over 11 locations in the country during 1993-94. In this trial, the mutant line ranked 3rd by producing an average yield of 1,528 kg/ha as compared to the two check varieties 'Punjab-91' (1,316 kg/ha) and 'Paidar-91' (1,391 kg/ha). The mutant line CMN-446-4 is moderately resistant to gram blight, highly resistant to stored pest (pulse beetle), contains 25.3% more protein as compared to the parental variety 6153 and is also better in nitrogen fixing capacity.The proposal for release of the mutant line CMN-446-4 as a new variety under the name 'NIFA-95' for general cultivation in the rainfed

  5. Yield of two mutant lines of soybean for human consumption

    International Nuclear Information System (INIS)

    Salmeron E, J.; Mastache L, A. A.; Diaz V, G. E.; Valencia E, F.; Ranfla C, R.; Melendez P, M.; Cervantes S, T.; De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.

    2009-01-01

    The present work has the objective of to evaluate the yield and the agronomic behavior of 2 mutant lines of soybean for human consumption, obtained by means of a process of recurrent irradiation of soybean seed ISAAEG-BM 2 with gammas of Co 60 and selection in the generation R 4 M 18 . For the variable yield significant statistical differences were not observed, but considering the rest of the evaluated agronomic characteristics the mutant lines L 6 and Bombona they were excellent with values of 3,934.6 and 3,806.8 Kg ha- 1 to 15% of grain humidity, they also possess excellent genetic characteristics result of the irradiations and selections of these new genetic materials. (Author)

  6. Short communication. A spontaneous mutant of L-202 rice

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Yzaguire, A.; Padrones, T.

    2009-07-01

    A new spontaneous phenotype of the rice cultivar L-202 was found. Mendelian analysis indicates that it is a monogenic, recessive mutant. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tillering and relatively short height. The objectives of this study were: to characterize it, to determine if it is heritable and if so, its genetic basis. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tillering and relatively short height. Selfing the new phenotype resulted in a uniform progeny, with the traits of the parent plant (wild type). Crossing the new phenotype with the normal L-202 cultivar resulted in a uniform F1 hybrid generation, with the wild type. The F2 generation showed a mendelian segregation which did not depart significantly from three normal plants : one new phenotype. It is concluded that it is a monogenic, recessive mutant. (Author) 3 refs.

  7. Early ripening, productive soybean mutant variety suitable for combine harvesting

    International Nuclear Information System (INIS)

    Krausse, G.W.

    1989-01-01

    Between 1979 and 1981 seeds of the early ripening Swedish variety ''Fiskeby V'' were treated with N-nitroso-N-methylurea, sodium azide or gamma rays. Induced mutants were selected which are characterized by longer stalk, higher insertion point of the lowest pods and improved grain yield as well as sufficiently early maturity. Starting from 60 000 treated seeds, 6 mutant lines were developed, and in 1988 one variety named ''Dorado'' was released. Under optimal agrotechnical conditions in fields of 2-10 ha ''Dorado'' achieved grain yields between 1,5 and 2,3 t/ha during the last four years. It is intended to grow this variety in the middle and southern districts of the German Democratic Republic, primarily for human consumption. A technology for growing this variety was recommended

  8. Antisense downregulation of mutant huntingtin in a cell model

    DEFF Research Database (Denmark)

    Hasholt, L.; Abell, K.; Norremolle, A.

    2003-01-01

    or by addition to the culture medium. Results Expression of the fusion protein containing the mutant huntingtin fragment resulted in diffuse green fluorescence in the cytoplasm and formation of aggregates in some of the NT2 cells and NT2-N neurons. We obtained antisense sequence-specific inhibition of expression...... of the fusion protein and/or suppression of the aggregate formation in both cell types. In the NT2 cells the antisense effect was dependent on the way of administration of the oligo. Conclusions The PS-antisense oligo is effective in downregulation of mutant huntingtin, and the reduction of aggregate formation...... is a sensitive biological marker. The findings suggest that antisense knockdown of huntingtin could be a useful strategy for treatment of HD, and could also be suitable for studies of the normal and pathological function of huntingtin in different cellular model systems....

  9. No evidence for cardiac dysfunction in Kif6 mutant mice.

    Directory of Open Access Journals (Sweden)

    Abdul Hameed

    Full Text Available A KIF6 variant in man has been reported to be associated with adverse cardiovascular outcomes after myocardial infarction. No clear biological or physiological data exist for Kif6. We sought to investigate the impact of a deleterious KIF6 mutation on cardiac function in mice. Kif6 mutant mice were generated and verified. Cardiac function was assessed by serial echocardiography at baseline, after ageing and after exercise. Lipid levels were also measured. No discernable adverse lipid or cardiac phenotype was detected in Kif6 mutant mice. These data suggest that dysfunction of Kif6 is linked to other more complex biological/biochemical parameters or is unlikely to be of material consequence in cardiac function.

  10. Characterizing visible and invisible cell wall mutant phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, Nicholas C.; McCann, Maureen C.

    2015-04-06

    About 10% of a plant's genome is devoted to generating the protein machinery to synthesize, remodel, and deconstruct the cell wall. High-throughput genome sequencing technologies have enabled a reasonably complete inventory of wall-related genes that can be assembled into families of common evolutionary origin. Assigning function to each gene family member has been aided immensely by identification of mutants with visible phenotypes or by chemical and spectroscopic analysis of mutants with ‘invisible’ phenotypes of modified cell wall composition and architecture that do not otherwise affect plant growth or development. This review connects the inference of gene function on the basis of deviation from the wild type in genetic functional analyses to insights provided by modern analytical techniques that have brought us ever closer to elucidating the sequence structures of the major polysaccharide components of the plant cell wall.

  11. Search for methylation-sensitive amplification polymorphisms in mutant figs

    OpenAIRE

    Rodrigues, M. G F; Martins, A. B G [UNESP; Bertoni, B. W.; Figueira, A.; Giuliatti, S.

    2013-01-01

    Fig (Ficus carica) breeding programs that use conventional approaches to develop new cultivars are rare, owing to limited genetic variability and the difficulty in obtaining plants via gamete fusion. Cytosine methylation in plants leads to gene repression, thereby affecting transcription without changing the DNA sequence. Previous studies using random amplification of polymorphic DNA and amplified fragment length polymorphism markers revealed no polymorphisms among select fig mutants that ori...

  12. Gamma radiation induced mutant for improved yield components in sunflower

    International Nuclear Information System (INIS)

    Elangovan, M.

    2001-01-01

    Sunflower has become an important oilseed in the Indian vegetable oil pool following its introduction from Russia in 1969. It can be used for all quality products useful to humans. The need for genetic variability and new useful gene sources has necessitated that sunflower breeders and geneticists utilize a wide range of germplasm in their breeding programmes. The induction of mutations in sunflower by physical and chemical mutagens has been practiced quite intensively in the last two decades. The results recorded to date suggest that utilization of mutagenesis could be a great advantage in improving the sunflower crop. An induced mutation programme was undertaken to generate variability in the variety 'Morden' using gamma rays. The certified and genetically pure seeds were irradiated with 50, 100, and 150 Gy gamma rays and used for further studies. Selection in M 2 generations, raised from different treatments, revealed the presence of an erectophylly leaf mutant from 50 Gy treatment. The isolated mutant showed improved yield components like head diameter, 100- seed weight and yield per plant. The mutant was a plant with short petiole length and erect leaves. This type of leaf get sunlight throughout the day. From morning to afternoon, the first half of the leaf gets sunlight, and from afternoon to evening the second half of the leaf gets sunlight. As a result of getting sunlight the whole day, the plant had more photosynthetic products and grew vigorously. Plant height, head diameter and 100-seed weight had direct effect on seed yield, and the number of leaves and stem diameter influenced the seed yield indirectly. In the M 3 generation, the mutant showed an almost two-fold increase over the parent variety for all investigated characters, except that of the yield per plant where there was a three-fold increase. The present investigation has shown that there are remarkable possibilities of increasing the yield components in sunflower by induced mutations

  13. Molecular Determinants of Mutant Phenotypes, Inferred from Saturation Mutagenesis Data.

    Science.gov (United States)

    Tripathi, Arti; Gupta, Kritika; Khare, Shruti; Jain, Pankaj C; Patel, Siddharth; Kumar, Prasanth; Pulianmackal, Ajai J; Aghera, Nilesh; Varadarajan, Raghavan

    2016-11-01

    Understanding how mutations affect protein activity and organismal fitness is a major challenge. We used saturation mutagenesis combined with deep sequencing to determine mutational sensitivity scores for 1,664 single-site mutants of the 101 residue Escherichia coli cytotoxin, CcdB at seven different expression levels. Active-site residues could be distinguished from buried ones, based on their differential tolerance to aliphatic and charged amino acid substitutions. At nonactive-site positions, the average mutational tolerance correlated better with depth from the protein surface than with accessibility. Remarkably, similar results were observed for two other small proteins, PDZ domain (PSD95 pdz3 ) and IgG-binding domain of protein G (GB1). Mutational sensitivity data obtained with CcdB were used to derive a procedure for predicting functional effects of mutations. Results compared favorably with those of two widely used computational predictors. In vitro characterization of 80 single, nonactive-site mutants of CcdB showed that activity in vivo correlates moderately with thermal stability and solubility. The inability to refold reversibly, as well as a decreased folding rate in vitro, is associated with decreased activity in vivo. Upon probing the effect of modulating expression of various proteases and chaperones on mutant phenotypes, most deleterious mutants showed an increased in vivo activity and solubility only upon over-expression of either Trigger factor or SecB ATP-independent chaperones. Collectively, these data suggest that folding kinetics rather than protein stability is the primary determinant of activity in vivo This study enhances our understanding of how mutations affect phenotype, as well as the ability to predict fitness effects of point mutations. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Assessment of Genetic diversity in mutant cowpea lines using ...

    African Journals Online (AJOL)

    FKOLADE

    2016-11-09

    Nov 9, 2016 ... DNA extraction. The seeds of the mutants and their parents were planted out in pots in the screen house, and young leaves were harvested from them ... The PCR was done using a modified touch down progam as follows: 94°C for 2 min, 12 cycles of 2 min at 94°C, one min at 65°C. (-0.7°C per cycle) and 1 ...

  15. Genetic Segregation Analysis of a Rapeseed Dwarf Mutant

    International Nuclear Information System (INIS)

    Xiang, G.; Yu, S.; Zhang, T.; Zhao, J.; Lei, S.; Du, C.

    2016-01-01

    Dwarf resources in Brassica napus are very important for developing high-yield cultivars through dwarf-type and lodging-resistant breeding. However, few dwarf varieties have been available for this species. Here, we reported a new rapeseed dwarf mutant GRC1157, which exhibits obvious phenotypic variations on dwarf. Six generations (P /sub 1/, P/sub 1/, F/sub 1/, F/sub 1/, B/sub 1/, and B/sub 1/) were produced from a cross between dwarf mutant GRC1157 and an elite tall-type line XR16 to analyze genetic inheritances of plant height (PH), numbers of the 1st valid branch (VBN), main inflorescence length (MIL), pod numbers per main inflorescence (MPN), pod length (PL) and seed numbers per pod (PSN) using the mixed major gene plus polygene inheritance model. The genetic analysis shows different traits were controlled by different inheritance models: PH and PL by two pairs of additive-dominant-epistatic major genes plus additive-dominant-epistatic polygenes, MPN and PSN by two-pair additive-dominant-epistatic major genes plus additive-dominant polygenes, MIL by two-pair additive-dominant-epistatic major genes and VBN by one-pair additive-dominant major genes plus additive-dominant-epistatic polygenes. Furthermore, positive correlations between PH and some other traits were observed, suggesting that some traits may be co-regulated by several linkage or same loci/genes. In addition, high heritability (40.35-93.7 percent) were found for five traits (except VBN) in different segregating generations, indicating these traits were mainly affected by hereditary factors and suitable for early artificial selection. In sum, the dwarf mutant GRC1157 can serve as a valuable resource for rapeseed dwarf breeding and the genetic analysis in this study provided a foundation for further mapping and cloning dwarf genes in mutant GRC1157. (author)

  16. Breeding cultivars of barley and mustard containing biochemical mutants

    Energy Technology Data Exchange (ETDEWEB)

    Oram, R N [Division of Plant industry, CSIRO, Canberra (Australia)

    1990-01-01

    Full text: The inactivation of dominant and co-dominant alleles is becoming increasingly important in changing the composition of seed carbohydrates, protein, oil, fibre and secondary products to suit modern food and feed technologies. In barley, breeding lines adapted to south-eastern Australian conditions have been developed containing a waxy endosperm from the Japanese variety 'Sumire Mochi', the high lysine gene lys from cv. 'Hiproly' of Ethiopia, and the induced high lysine mutant gene lys 3a from 'Risoe 1508'. The improved mutant lines yield 12-34% less than the highest yielding feed barley. The lys and lys 3a alleles suppress the formation of prolamins, the waxy allele inhibits the formation of amylose. It seems difficult to modify the background genotype to fully compensate for the reduction of major storage carbohydrate or protein compounds. However, waxy barleys have uses in some human foods and a premium can be paid to producers. The grain of the provisionally-patented waxy cultivar Wasiro is suitable for pearling. It contains 5% {beta}-glucan (soluble fibre) and therefore should be as effective as oat bran for reducing blood cholesterol. In Indian mustard (Brassica juncea), three cultivars differing in date of maturity, each containing the spontaneous mutant alleles for low erucic acid levels in the seed oil, have been developed to produce a high quality, mildly flavoured cooking/salad oil. The concentration of glucosinolates in the seed meal must be reduced to make it palatable and non-toxic to pigs and poultry. Three B. juncea lines were treated in up to four successive generations with gamma rays or EMS. 60,000 seed samples were analysed in subsequent generations. Two induced mutants with reduced glucosinolate concentrations are now available besides 4 naturally-occurring sources with only little reduced yields. Recombination may give a high-yielding low erucic acid and low glucosinolate variety of B. juncea. (author)

  17. Mutant strain screening and its enzyme production conditions of cellulase

    International Nuclear Information System (INIS)

    Dong Zhiyang; Zhu Lingxiang; Yu Wei

    2001-01-01

    Trichoderma koeningii T-801, which can produce relatively high cellulase, was isolated. The ability of producing cellulase of mutant T-801 had increased 1.77 times after treated with nitrous guanide and γ-ray and was higher than that of Trichoderma QM9414. The medium with straw powder as carbon source and peptone as nitrogen source is optimal and the maximum cellulase activity is reached at 30 degree C and pH 5.0 when cultured for 5 days

  18. Xylitol production by a Pichia stipitis D-xylulokinase mutant

    Science.gov (United States)

    Yong-Su Jin; Jose Cruz; Thomas W. Jeffries

    2005-01-01

    Xylitol production by Pichia stipitis FPL-YS30, a xyl3-Ä1 mutant that metabolizes xylose using an alternative metabolic pathway, was investigated under aerobic and oxygen-limited culture conditions. Under both culture conditions, FPL-YS30 (xyl3-Ä1) produced a negligible amount of ethanol and converted xylose mainly into xylitol with comparable yields (0.30 and 0.27 g...

  19. Breeding cultivars of barley and mustard containing biochemical mutants

    International Nuclear Information System (INIS)

    Oram, R.N.

    1990-01-01

    Full text: The inactivation of dominant and co-dominant alleles is becoming increasingly important in changing the composition of seed carbohydrates, protein, oil, fibre and secondary products to suit modern food and feed technologies. In barley, breeding lines adapted to south-eastern Australian conditions have been developed containing a waxy endosperm from the Japanese variety 'Sumire Mochi', the high lysine gene lys from cv. 'Hiproly' of Ethiopia, and the induced high lysine mutant gene lys 3a from 'Risoe 1508'. The improved mutant lines yield 12-34% less than the highest yielding feed barley. The lys and lys 3a alleles suppress the formation of prolamins, the waxy allele inhibits the formation of amylose. It seems difficult to modify the background genotype to fully compensate for the reduction of major storage carbohydrate or protein compounds. However, waxy barleys have uses in some human foods and a premium can be paid to producers. The grain of the provisionally-patented waxy cultivar Wasiro is suitable for pearling. It contains 5% β-glucan (soluble fibre) and therefore should be as effective as oat bran for reducing blood cholesterol. In Indian mustard (Brassica juncea), three cultivars differing in date of maturity, each containing the spontaneous mutant alleles for low erucic acid levels in the seed oil, have been developed to produce a high quality, mildly flavoured cooking/salad oil. The concentration of glucosinolates in the seed meal must be reduced to make it palatable and non-toxic to pigs and poultry. Three B. juncea lines were treated in up to four successive generations with gamma rays or EMS. 60,000 seed samples were analysed in subsequent generations. Two induced mutants with reduced glucosinolate concentrations are now available besides 4 naturally-occurring sources with only little reduced yields. Recombination may give a high-yielding low erucic acid and low glucosinolate variety of B. juncea. (author)

  20. Prion propagation in cells expressing PrP glycosylation mutants.

    Science.gov (United States)

    Salamat, Muhammad K; Dron, Michel; Chapuis, Jérôme; Langevin, Christelle; Laude, Hubert

    2011-04-01

    Infection by prions involves conversion of a host-encoded cell surface protein (PrP(C)) to a disease-related isoform (PrP(Sc)). PrP(C) carries two glycosylation sites variably occupied by complex N-glycans, which have been suggested by previous studies to influence the susceptibility to these diseases and to determine characteristics of prion strains. We used the Rov cell system, which is susceptible to sheep prions, to generate a series of PrP(C) glycosylation mutants with mutations at one or both attachment sites. We examined their subcellular trafficking and ability to convert into PrP(Sc) and to sustain stable prion propagation in the absence of wild-type PrP. The susceptibility to infection of mutants monoglycosylated at either site differed dramatically depending on the amino acid substitution. Aglycosylated double mutants showed overaccumulation in the Golgi compartment and failed to be infected. Introduction of an ectopic glycosylation site near the N terminus fully restored cell surface expression of PrP but not convertibility into PrP(Sc), while PrP(C) with three glycosylation sites conferred cell permissiveness to infection similarly to the wild type. In contrast, predominantly aglycosylated molecules with nonmutated N-glycosylation sequons, produced in cells expressing glycosylphosphatidylinositol-anchorless PrP(C), were able to form infectious PrP(Sc). Together our findings suggest that glycosylation is important for efficient trafficking of anchored PrP to the cell surface and sustained prion propagation. However, properly trafficked glycosylation mutants were not necessarily prone to conversion, thus making it difficult in such studies to discern whether the amino acid changes or glycan chain removal most influences the permissiveness to prion infection.

  1. GPNMB ameliorates mutant TDP-43-induced motor neuron cell death.

    Science.gov (United States)

    Nagahara, Yuki; Shimazawa, Masamitsu; Ohuchi, Kazuki; Ito, Junko; Takahashi, Hitoshi; Tsuruma, Kazuhiro; Kakita, Akiyoshi; Hara, Hideaki

    2017-08-01

    Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP-43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP-43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)-positive astrocyte and ionized calcium binding adaptor molecule-1 (Iba1)-positive microglia. GPNMB aggregates were localized in the microtubule-associated protein 2 (MAP-2)-positive neuron and neurofilament H non-phosphorylated (SMI-32)-positive neuron, and these were co-localized with TDP-43 aggregates in the spinal cord of ALS patients. Mock or TDP-43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP-43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP-43 plasmids and serum-free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP-43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP-43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Induction and use of artificial mutants in sweet potato

    International Nuclear Information System (INIS)

    Marumine, Shokichi

    1984-01-01

    X-ray, ethylene imine, 32 P and 60 Co were used as mutagen for sweet potato mutation breeding and visible variations were observed for all mutagen. In the case of 60 Co irradiation, mutation rate of skin color is 0.5-1.3% based on cutting. Direction and variation of dry matter and tuber yield of mutants which were induced by 32 P and/or 60 Co irradiation showed more deteriorative variation than progressive variation but some induced mutant lines show same or superior characters than original line. In the case of 32 P irradiation to tuber, obstruction is not so much up to dese of 10,000 μci per tuber but treatment of 330 μci per cutting approximate to LD 50 . By tuber treatment with 60 Co gamma rays, suppression of sprouting occurred in dose of 30kR. Tendency to increase a variation was not observed at higher doses. 50-200 μci per cutting or 300-500 μci per tuber in 32 P treatment and 15 kR in 60 Co gamma-irradiation for tuber seemed to be optimum dosages. Hybrid seed of mutant selected for dry matter content was compared with that of original line and it was concluded that the variation of selected line was genetic. Mutant induced by 32 P and 60 Co treatment was used as a parental material and progeny of the cross was selected for practical characters. As a result, a line of higher starch yield with high resistance to pest and disease was selected and this line was used as parental material of further breeding. (author)

  3. Dwarf mutant of Papaver somniferum with high morphine content

    International Nuclear Information System (INIS)

    Chauhan, S.P.; Patra, N.K.; Srivastava, H.K.

    1987-01-01

    Opium poppy, Papaver somniferum L. is an important medicinal plant known for its morphine, codeine, and thebaine alkaloids. This Institute had earlier released two latex opium yielding poppy varieties, Shyama and Shweta, which are now cultivated by the farmers under the supervision of the Narcotic Department of the Government of India. However, both these varieties became susceptible to downy mildew (Peronospora arborescens). Lodging due to heavy capsule weight is another problem affecting latex yield. With these problems in mind, we undertook mutation breeding on the above mentioned two varieties employing gamma rays (5 kR, 15 kR, 20 kR) and EMS (0.2%, 0.4%, 0.6%) and combined mutagens (5 kR + 0.2% EMS, 5 kR + 0.4% EMS and 5 kR + 0.6% EMS). M 1 from the treated seeds (405 plants) was raised in winter 1984-85. M 2 generation of 13,500 plants (i.e. 270 M 1 progenies x 50 plants) was raised in winter 1985/86. A dwarf mutant with high morphine content was identified in M 2 from the variety Shweta treated with 5 kR + 0.4% EMS. The mutant differs by its dwarf stature, compact leaf arrangements, multilocular capsules, increased capsule number, and small capsule size. The mutant is under testing for its superior morphine production. It may be used as dwarf gene source in hybridization for improving lodging resistance. This mutant is a novel type, which was not available in our germplasm collection

  4. Modeling the dual pacemaker system of the tau mutant hamster.

    Science.gov (United States)

    Oda, G A; Menaker, M; Friesen, W O

    2000-06-01

    Circadian pacemakers in many animals are compound. In rodents, a two-oscillator model of the pacemaker composed of an evening (E) and a morning (M) oscillator has been proposed based on the phenomenon of "splitting" and bimodal activity peaks. The authors describe computer simulations of the pacemaker in tau mutant hamsters viewed as a system of mutually coupled E and M oscillators. These mutant animals exhibit normal type 1 PRCs when released into DD but make a transition to a type 0 PRC when held for many weeks in DD. The two-oscillator model describes particularly well some recent behavioral experiments on these hamsters. The authors sought to determine the relationships between oscillator amplitude, period, PRC, and activity duration through computer simulations. Two complementary approaches proved useful for analyzing weakly coupled oscillator systems. The authors adopted a "distinct oscillators" view when considering the component E and M oscillators and a "system" view when considering the system as a whole. For strongly coupled systems, only the system view is appropriate. The simulations lead the authors to two primary conjectures: (1) the total amplitude of the pacemaker system in tau mutant hamsters is less than in the wild-type animals, and (2) the coupling between the unit E and M oscillators is weakened during continuous exposure of hamsters to DD. As coupling strength decreases, activity duration (alpha) increases due to a greater phase difference between E and M. At the same time, the total amplitude of the system decreases, causing an increase in observable PRC amplitudes. Reduced coupling also increases the relative autonomy of the unit oscillators. The relatively autonomous phase shifts of E and M oscillators can account for both immediate compression and expansion of activity bands in tau mutant and wild-type hamsters subjected to light pulses.

  5. Search for methylation-sensitive amplification polymorphisms in mutant figs.

    Science.gov (United States)

    Rodrigues, M G F; Martins, A B G; Bertoni, B W; Figueira, A; Giuliatti, S

    2013-07-08

    Fig (Ficus carica) breeding programs that use conventional approaches to develop new cultivars are rare, owing to limited genetic variability and the difficulty in obtaining plants via gamete fusion. Cytosine methylation in plants leads to gene repression, thereby affecting transcription without changing the DNA sequence. Previous studies using random amplification of polymorphic DNA and amplified fragment length polymorphism markers revealed no polymorphisms among select fig mutants that originated from gamma-irradiated buds. Therefore, we conducted methylation-sensitive amplified polymorphism analysis to verify the existence of variability due to epigenetic DNA methylation among these mutant selections compared to the main cultivar 'Roxo-de-Valinhos'. Samples of genomic DNA were double-digested with either HpaII (methylation sensitive) or MspI (methylation insensitive) and with EcoRI. Fourteen primer combinations were tested, and on an average, non-methylated CCGG, symmetrically methylated CmCGG, and hemimethylated hmCCGG sites accounted for 87.9, 10.1, and 2.0%, respectively. MSAP analysis was effective in detecting differentially methylated sites in the genomic DNA of fig mutants, and methylation may be responsible for the phenotypic variation between treatments. Further analyses such as polymorphic DNA sequencing are necessary to validate these differences, standardize the regions of methylation, and analyze reads using bioinformatic tools.

  6. Mutant p53 protein localized in the cytoplasm inhibits autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Tasdemir, Ezgi; Maiuri, Maria Chiara; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Vicencio, José Miguel; Soussi, Thierry; Kroemer, Guido

    2008-10-01

    The knockout, knockdown or chemical inhibition of p53 stimulates autophagy. Moreover, autophagy-inducing stimuli such as nutrient depletion, rapamycin or lithium cause the depletion of cytoplasmic p53, which in turn is required for the induction of autophagy. Here, we show that retransfection of p53(-/-) HCT 116 colon carcinoma cells with wild type p53 decreases autophagy down to baseline levels. Surprisingly, one third among a panel of 22 cancer-associated p53 single amino acid mutants also inhibited autophagy when transfected into p53(-/-) cells. Those variants of p53 that preferentially localize to the cytoplasm effectively repressed autophagy, whereas p53 mutants that display a prominently nuclear distribution failed to inhibit autophagy. The investigation of a series of deletion mutants revealed that removal of the DNA-binding domain from p53 fails to interfere with its role in the regulation of autophagy. Altogether, these results identify the cytoplasmic localization of p53 as the most important feature for p53-mediated autophagy inhibition. Moreover, the structural requirements for the two biological activities of extranuclear p53, namely induction of apoptosis and inhibition of autophagy, are manifestly different.

  7. Molecular Imaging Of Metabolic Reprogramming In Mutant IDH Cells

    Directory of Open Access Journals (Sweden)

    Pavithra eViswanath

    2016-03-01

    Full Text Available Mutations in the metabolic enzyme isocitrate dehydrogenase (IDH have recently been identified as drivers in the development of several tumor types. Most notably, cytosolic IDH1 is mutated in 70-90% of low-grade gliomas and upgraded glioblastomas, and mitochondrial IDH2 is mutated in ~20% of acute myeloid leukemia cases. Wild-type IDH catalyzes the interconversion of isocitrate to α-ketoglutarate (α-KG. Mutations in the enzyme lead to loss of wild-type enzymatic activity and a neomorphic activity that converts α-KG to 2-hydroxyglutarate (2-HG. In turn, 2-HG, which has been termed an oncometabolite, inhibits key α-KG- dependent enzymes, resulting in alterations of the cellular epigenetic profile and, subsequently, inhibition of differentiation and initiation of tumorigenesis. In addition, it is now clear that the IDH mutation also induces a broad metabolic reprogramming that extends beyond 2-HG production, and this reprogramming often differs from what has been previously reported in other cancer types. In this review we will discuss in detail what is known to date about the metabolic reprogramming of mutant IDH cells and how this reprogramming has been investigated using molecular metabolic imaging. We will describe how metabolic imaging has helped shed light on the basic biology of mutant IDH cells and how this information can be leveraged to identify new therapeutic targets and to develop new clinically translatable imaging methods to detect and monitor mutant IDH tumors in vivo.

  8. Oncogenic Signaling by Leukemia-Associated Mutant Cbl Proteins

    Science.gov (United States)

    Nadeau, Scott; An, Wei; Palermo, Nick; Feng, Dan; Ahmad, Gulzar; Dong, Lin; Borgstahl, Gloria E. O.; Natarajan, Amarnath; Naramura, Mayumi; Band, Vimla; Band, Hamid

    2013-01-01

    Members of the Cbl protein family (Cbl, Cbl-b, and Cbl-c) are E3 ubiquitin ligases that have emerged as critical negative regulators of protein tyrosine kinase (PTK) signaling. This function reflects their ability to directly interact with activated PTKs and to target them as well as their associated signaling components for ubiquitination. Given the critical roles of PTK signaling in driving oncogenesis, recent studies in animal models and genetic analyses in human cancer have firmly established that Cbl proteins function as tumor suppressors. Missense mutations or small in-frame deletions within the regions of Cbl protein that are essential for its E3 activity have been identified in nearly 5% of leukemia patients with myelodysplastic/myeloproliferative disorders. Based on evidence from cell culture studies, in vivo models and clinical data, we discuss the potential signaling mechanisms of mutant Cbl-driven oncogenesis. Mechanistic insights into oncogenic Cbl mutants and associated animal models are likely to enhance our understanding of normal hematopoietic stem cell homeostasis and provide avenues for targeted therapy of mutant Cbl-driven cancers. PMID:23997989

  9. Selection Of Drought Resistant Mutants In Rice Using DNA Markers

    International Nuclear Information System (INIS)

    Nguyen Duc Thanh; Le Thi Bich Thuy; Dang Thi Minh Lua

    2008-01-01

    In recent years, the marker - assisted selection (MAS) strategy have been used for selection of traits that are difficult and costly performed measurement and score. Selection for a well-developed root system could improve the drought resistance of rice as the plant would avoid water stress by absorbing water from the soil. There were several reports on map construction and identification of the markers tightly linked to morphological and physiological traits related to drought resistance in rice, in particular, root traits in upland and lowland rice (Champoux et al., 1995; Ray et al., 1996; Price et al., 1997, 2000; Yadav et al., 1997). In this report, we present the results on selection of drought resistance mutants in rice using the DNA markers tightly linked to root traits favorable for drought resistance. The mutant rice lines were obtained from irradiated seeds and calluses by gamma ray. The selection was performed at M2 mutants using the DNA markers linked to maximum root length (MRL), root weight to shoot weight ratio (RW/SR), and weight of deep root to shoot weight ratio (DRW/SR). The obtained results showed that there were many lines possessed drought resistant markers. In addition, there is a number of lines have altered genome. Several lines having drought markers proved to be more resistant to drought in green-house test. These lines could be useful for further test and development of drought resistant varieties. (author)

  10. Evaluation of artemisia mutant lines conducted from gamma irradiation treatment

    International Nuclear Information System (INIS)

    Ragapadmi Purnamaningsih; EG Lestari; M Syukur

    2010-01-01

    Cases of Malaria diseases attack in Indonesia has been increasing. Plasmodium falciparum the cause of malaria disease is now resistant to the usual medicine. One of malaria medicine which recommended by WHO is artemisinine compound extracted from Artemisia annua L plant. Low artemisinine content is one problem of Artemisia development in Indonesia. Increasing genetic variation using gamma irradiation is one alternative method to improve artemisinin content. In 2007, induce mutation had been done to artemisia seeds using gamma irradiation at dosage of 10-100 Gy. The good rooting planlet was regenerated and acclimatized in the green house, and then the seedling (M0 generation) was planted in the field at 1545 m asl. Plants derived from seeds without gamma irradiation treatment and cultured in vitro (in vitro control) were used as control. The result showed there were some morphological variations between the mutant lines (plant height, shape of the leaves and time of flowering). Ten mutant lines were selected based on biomass yield and analyzed for the artemisinine content.The result showed that artemisinine content of the mutant lines ranged from 0.44 - 1.41%, and it was significantly higher than that of in vitro control (0.43%). (author)

  11. Histological Characterization of the Dicer1 Mutant Zebrafish Retina

    Directory of Open Access Journals (Sweden)

    Saeed Akhtar

    2015-01-01

    Full Text Available DICER1, a multidomain RNase III endoribonuclease, plays a critical role in microRNA (miRNA and RNA-interference (RNAi functional pathways. Loss of Dicer1 affects different developmental processes. Dicer1 is essential for retinal development and maintenance. DICER1 was recently shown to have another function of silencing the toxicity of Alu RNAs in retinal pigment epithelium (RPE cells, which are involved in the pathogenesis of age related macular degeneration. In this study, we characterized a Dicer1 mutant fish line, which carries a nonsense mutation (W1457Ter induced by N-ethyl-N-nitrosourea mutagenesis. Zebrafish DICER1 protein is highly conserved in the evolution. Zebrafish Dicer1 is expressed at the earliest stages of zebrafish development and persists into late developmental stages; it is widely expressed in adult tissues. Homozygous Dicer1 mutant fish (DICER1W1457Ter/W1457Ter have an arrest in early growth with significantly smaller eyes and are dead at 14–18 dpf. Heterozygous Dicer1 mutant fish have similar retinal structure to that of control fish; the retinal pigment epithelium (RPE cells are normal with no sign of degeneration at the age of 20 months.

  12. Potent inhibition of HIV-1 replication by a Tat mutant.

    Directory of Open Access Journals (Sweden)

    Luke W Meredith

    Full Text Available Herein we describe a mutant of the two-exon HIV-1 Tat protein, termed Nullbasic, that potently inhibits multiple steps of the HIV-1 replication cycle. Nullbasic was created by replacing the entire arginine-rich basic domain of wild type Tat with glycine/alanine residues. Like similarly mutated one-exon Tat mutants, Nullbasic exhibited transdominant negative effects on Tat-dependent transactivation. However, unlike previously reported mutants, we discovered that Nullbasic also strongly suppressed the expression of unspliced and singly-spliced viral mRNA, an activity likely caused by redistribution and thus functional inhibition of HIV-1 Rev. Furthermore, HIV-1 virion particles produced by cells expressing Nullbasic had severely reduced infectivity, a defect attributable to a reduced ability of the virions to undergo reverse transcription. Combination of these inhibitory effects on transactivation, Rev-dependent mRNA transport and reverse transcription meant that permissive cells constitutively expressing Nullbasic were highly resistant to a spreading infection by HIV-1. Nullbasic and its activities thus provide potential insights into the development of potent antiviral therapeutics that target multiple stages of HIV-1 infection.

  13. Functional verification of a porcine myostatin propeptide mutant.

    Science.gov (United States)

    Ma, Dezun; Jiang, Shengwang; Gao, Pengfei; Qian, Lili; Wang, Qingqing; Cai, Chunbo; Xiao, Gaojun; Yang, Jinzeng; Cui, Wentao

    2015-10-01

    Myostatin is a member of TGF-β superfamily that acts as a key negative regulator in development and growth of embryonic and postnatal muscles. In this study, the inhibitory activities of recombinant porcine myostatin propeptide and its mutated form (at the cleavage site of metalloproteinases of BMP-1/TLD family) against murine myostatin was evaluated in vivo by intraperitoneal injection into mice. Results showed that both wild type and mutated form of porcine propeptide significantly inhibited myostatin activity in vivo. The average body weight of mice receiving wild type propeptide or its mutated form increased by 12.5 % and 24.14%, respectively, compared to mice injected with PBS, implying that the in vivo efficacy of porcine propeptide mutant is greater than its wild type propeptide. Transgenic mice expressing porcine myostatin propeptide mutant were generated to further verify the results obtained from mice injected with recombinant porcine propeptide mutant. Compared with wild type (non-transgenic) mice, relative weight of gastrocnemius, rectusfemoris, and tibialis anterior increased by 22.14 %, 34.13 %, 25.37%, respectively, in transgenic male mice, and by 19.90 %, 42.47 %, 45.61%, respectively, in transgenic female mice. Our data also demonstrated that the mechanism by which muscle growth enhancement is achieved by these propeptides is due to an increase in fiber sizes, not by an increase in number of fiber cells.

  14. Recombination Phenotypes of Escherichia coli greA Mutants

    Directory of Open Access Journals (Sweden)

    Poteete Anthony R

    2011-03-01

    Full Text Available Abstract Background The elongation factor GreA binds to RNA polymerase and modulates transcriptional pausing. Some recent research suggests that the primary role of GreA may not be to regulate gene expression, but rather, to promote the progression of replication forks which collide with RNA polymerase, and which might otherwise collapse. Replication fork collapse is known to generate dsDNA breaks, which can be recombinogenic. It follows that GreA malfunction could have consequences affecting homologous recombination. Results Escherichia coli mutants bearing substitutions of the active site acidic residues of the transcription elongation factor GreA, D41N and E44K, were isolated as suppressors of growth inhibition by a toxic variant of the bacteriophage lambda Red-beta recombination protein. These mutants, as well as a D41A greA mutant and a greA deletion, were tested for proficiency in recombination events. The mutations were found to increase the efficiency of RecA-RecBCD-mediated and RecA-Red-mediated recombination, which are replication-independent, and to decrease the efficiency of replication-dependent Red-mediated recombination. Conclusion These observations provide new evidence for a role of GreA in resolving conflicts between replication and transcription.

  15. Genes and Alcohol Consumption: Studies with Mutant Mice

    Science.gov (United States)

    Mayfield, Jody; Arends, Michael A.; Harris, R. Adron; Blednov, Yuri A.

    2017-01-01

    In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test. PMID:27055617

  16. Genetical, cytological and physiological studies on the induced mutants with special regard to effective methods for obtaining useful mutants in perennial woody plants

    International Nuclear Information System (INIS)

    Kukimura, H.; Ikeda, F.; Fujita, H.; Maeta, T.; Nakajima, K.; Katagiri, K.; Nakahira, K.; Somegou, M.

    1975-01-01

    The study was aimed at elucidating the biological aspects of artificially induced mutations in perennial tree crops and at promoting the utilization of such mutations in a practical breeding programme. A number of mutants obtained particularly in Cryptomeria and mulberry (Morus spp.) by means of gamma radiation were examined for their practical usefulness. Doses from 7.5 to 15.0 kR were used. In mulbery, some mutant strains showed increased shoot growth, and one mutant strain showed a remarkable increase also in rooting ability. Entire leaf mutants were investigated for their breeding behaviour. None of the mutant strains showed acquired disease resistance. Changes in the number of isozyme bands and different staining intensity was observed in all the mutant strains compared to the original strains

  17. Blue ghosts: a new method for isolating amber mutants defective in essential genes of Escherichia coli

    DEFF Research Database (Denmark)

    Brown, S; Brickman, E R; Beckwith, J

    1981-01-01

    We describe a technique which permits an easy screening for amber mutants defective in essential genes of Escherichia coli. Using this approach, we have isolated three amber mutants defective in the rho gene. An extension of the technique allows the detection of ochre mutants and transposon inser...

  18. 2-deoxyglucose as a selective agent for derepressed mutants of Pichia stipitis

    Science.gov (United States)

    Hassan K. Sreenath; Thomas W. Jeffries

    1998-01-01

    The glucose analog 2-deoxyglucose (2-DOG) has been used to obtain mutants derepressed for pentose metabolism. Some researchers have used 2-DOG alone whereas others have used it in the presence of a glucoserepressible carbon source. We examined both methods and screened mutant strains for improved use of xylose in the presence of glucose. Pichia stipitis mutants...

  19. Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Nygaard, Per

    1982-01-01

    , stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib...

  20. Heterotropic and homotropic cooperativity by a drug-metabolising mutant of cytochrome P450 BM3

    NARCIS (Netherlands)

    van Vugt-Lussenburg, B.M.A.; Damsten, M.C.; Maasdijk, D.M.; Vermeulen, N.P.E.; Commandeur, J.N.M.

    2006-01-01

    Recently, we described a triple mutant of the bacterial cytochrome P450 BM3 as the first mutant with affinity for drug-like compounds. In this paper, we show that this mutant, but not wild-type BM3, is able to metabolise testosterone and several drug-like molecules such as amodiaquine,

  1. Screening and identification of respiration deficiency mutants of yeasts (Saccharomyces Cerevisiae) induced by heavy ion irradiation

    International Nuclear Information System (INIS)

    Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei; Zhang Hong

    2006-01-01

    A screen of respiration deficiency mutants of Saccharomyces Cerevisiae induced by 5.19 MeV/u 22 Ne 5- ion irradiation is studied. Some respiration deficiency mutants, which are white colony phenotype in the selective culture of TTC medium, are obtained. The mutants are effectively identified by means of a new and simplified restriction analysis method. (authors)

  2. [Mutant prevention concentrations of antibacterial agents to ocular pathogenic bacteria].

    Science.gov (United States)

    Liang, Qing-Feng; Wang, Zhi-Qun; Li, Ran; Luo, Shi-Yun; Deng, Shi-Jing; Sun, Xu-Guang

    2009-01-01

    To establish a method to measure mutant prevention concentration (MPC) in vitro, and to measure MPC of antibacterial agents for ocular bacteria caused keratitis. It was an experimental study. Forty strains of ocular bacteria were separated from cornea in Beijing Institute of Ophthalmology, which included 8 strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively. The minimal inhibitory concentration (MIC) of the levofloxacin (LVF), ofloxacin (OFL), ciprofloxacin (CIP), norfloxacin (NFL), tobramycin (TOB) and chloromycetin (CHL) were determined by agar dilution method from National Committee of Clinical Laboratory Standard (NCCLS). The MPC were measured by accumulate-bacterial methods with bacterial population inoculated more than 1.2 x 10(10) colony forming units per milliliter with Mueller-Hinton broth and tryptic soy agar plate. With the software of SPSS 11.0, the datum such as the range of MIC, MPC, MIC90 and MPC90 were calculated, and the selection index (MPC90/ MI90) and mutant selection window (MSW) were obtained. The MI90 of LVF and TOB (4 mg/L) to Staphylococcus aureus strains were the lowest. CIP showed the lowest MIC90 (0.25 mg/L) to Pseudomonas aeruginosa among six kinds of antibacterial agents. The MIC90 of LVF to Staphylococcus epidermidis (256 mg/L), Streptococcus pneumoniae (1 mg/L) and Klebsiella pneumoniae (0.25 mg/L) were lower than other antibacterial agents. The MPC90, MSW and the MPC90/MIC90 of levofloxacin showed lower values compared with other antibacterial medicines. From all the datum, the MIC90 of CHL was the highest and the activity was the weakest. Although the activity of LVF was higher to every kind of bacteria, CIP had the highest activity antibacterial to Pseudomonas aeruginosa. The capacity of CHL and TOB was weaker than Quinolones for restricting resistant mutants on ocular bacteria. LVF had the strongest capacity for restricting resistant

  3. Mutants of Escherichia coli K-12 with enhanced resistance to ionizing radiation. 4. Peculiarities of recombination in Gamsup(r) mutants

    International Nuclear Information System (INIS)

    Bresler, S.E.; Kalinin, V.L.; Laneeva, N.I.

    1984-01-01

    Radioresistant mutant Gam sup(r) 444 differs from a wild type and from Gam sup(r) 445 mutant in decreased frequency of long episome heritage ORF 1 (pur E + -tsx + -proC + -lac + ) and F 14 (ilv + -argE + ), containing hot points of RecRecF - depending recombination and in increased frequency of chromosome mobilization and integrative suppression of temperature sensitive dna A46 mutation by sexual factor F. In this respect Gam sup(r) 444 mutant resembles rec BC sbs B mutant with RecF - recombination type

  4. Grain product of 34 soya mutant lines;Rendimiento de grano de 34 lineas mutantes de soya

    Energy Technology Data Exchange (ETDEWEB)

    Salmeron E, J.; Mastache L, A. A.; Valencia E, F.; Diaz V, G. E. [Colegio Superior Agropecuario del Estado de Guerrero, Vicente Guerrero No. 81, Col. Centro, 40000 Iguala, Guerrero (Mexico); Cervantes S, T. [Instituto de Recursos Geneticos y Productividad, Colegio de Posgraduados, Carretera Mexico-Texcoco Km. 36.5, Montecillo, 56230 Texcoco, Estado de Mexico (Mexico); De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.; Gatica T, M. A. [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    This work was development with the objective of obtaining information of the agronomic behavior of 34 soya mutant lines (R{sub 4}M{sub 18}) for human consumption and this way to select the 2 better lines. The genetic materials were obtained starting from the variety ISAAEG-B M2 by means of the application of recurrent radiation with Co{sup 60} gammas, to a dose of 350 Gray for the first two generations and both later to 200 Gray and selection during 17 cycles, being obtained the 34 better lines mutants with agronomic characteristic wanted and good flavor. The obtained results were that the mutant lines L{sub 25} and L{sub 32} produced the major quantity in branches/plant number with 7.5 and 7.25, pods/plant number with 171.25 and 167, grains/plant number with 350.89 and 333.07 and grain product (ton/ha) to 15% of humidity 5.15 and 4.68 ton/ha, respectively. (Author)

  5. Is auxin involved in the induction of genetic instability in barley homeotic double mutants?

    Science.gov (United States)

    Šiukšta, Raimondas; Vaitkūnienė, Virginija; Rančelis, Vytautas

    2018-02-01

    The triggers of genetic instability in barley homeotic double mutants are tweaky spike -type mutations associated with an auxin imbalance in separate spike phytomeres. Barley homeotic tweaky spike;Hooded (tw;Hd) double mutants are characterized by an inherited instability of spike and flower development, which is absent in the single parental constituents. The aim of the present study was to show that the trigger of genetic instability in the double mutants is the tw mutations, which are associated with an auxin imbalance in the developing spikes. Their pleiotropic effects on genes related to spike/flower development may cause the genetic instability of double mutants. The study of four double-mutant groups composed of different mutant alleles showed that the instability arose only if the mutant allele tw was a constituent of the double mutants. Application of auxin inhibitors and 2,4-dichlorophenoxyacetic acid (2,4-D) demonstrated the relationship of the instability of the double mutants and the phenotype of the tw mutants to auxin imbalance. 2,4-D induced phenocopies of the tw mutation in wild-type plants and rescued the phenotypes of three allelic tw mutants. The differential display (dd-PCR) method allowed the identification of several putative candidate genes in tw that may be responsible for the initiation of instability in the double mutants by pleiotropic variations of their expression in the tw mutant associated with auxin imbalance in the developing spikes. The results of the present study linked the genetic instability of homeotic double mutants with an auxin imbalance caused by one of the constituents (tw). The genetic instability of the double mutants in relation to auxin imbalance was studied for the first time. A matrocliny on instability expression was also observed.

  6. UV-induced lethal sectoring and pure mutant clones in yeast.

    Science.gov (United States)

    Hannan, M A; Duck, P; Nasim, A

    1976-08-01

    The induction of lethal sectoring and pure mutant clones by ultraviolet light has been studied in a homogeneous G1 population of Saccharomyces cerevisiae grown in a normal growth medium. At the lowest UV dose of 250 ergs, which corresponds to a shoulder in the survival curve, all mutants appeared as pure clones. At higher doses the frequency of mosaic mutants progressively increased. These results indicate a relationship between the highest frequency of complete mutants and the maximum repair activity. In addition, the frequency of lethal sectoring at all doses tested was too low to account for the origin of pure mutant clones.

  7. Studies on an X-ray induced crinkled leaf mutant of Trichosanthes anguina L

    International Nuclear Information System (INIS)

    Datta, Subodh Kumar

    1986-01-01

    Crinkled leaf mutant isolated in the second generation after treatment with X-ray bred true in subsequent generation. The mutant was a late flowering type with increased percentage of PMC's with chromosomal abnormality and pollen grain sterility. TLC study on phenolic compounds in leaves showed that both the mother line and the mutant had equal number of spots but they differed from each other with respect to four spots. Spot Nos. 2 and 4 of the mother line were absent in the mutant but the latter had two new spots (spot Nos. 11 and 12). The mutant and the mother line also differed from each other in pollen grain morohology. (author)

  8. Primary study on lesion mimic mutants of rice (oryza sativa L.)

    International Nuclear Information System (INIS)

    Hao Zhongna; Zhang Hongzhi; Tao Rongixang

    2007-01-01

    Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by γ-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear length of all mutants were 9.43-15.19 cm, and that of CK was 16.41 cm; the total grain quantity per spike of all mutants were 88.17-165.33, and those of xsl19 and CK were 49.50 and 76.17. The results showed all lesion mimic mutants except xsl19 had short spikes and total grain quantity per spike increasing. All lesion mimic mutants were susceptible to Magnaporthe grisea, and they had no relationship with resistance. (authors)

  9. Characteristics and use of wheat mutants tolerant or resistant to Septoria nodorum Berk

    International Nuclear Information System (INIS)

    Fossati, A.; Kleijer, G.; Fried, P.M.

    1983-01-01

    Mutation induction was used to obtain mutants tolerant or resistant to Septoria nodorum. This technique is valuable but many genotypes had to be treated because mutants could not be selected from all the genotypes. Short tolerant mutants could be obtained from 3 of the 15 treated tall tolerant lines. Induction of tolerance in susceptible lines of good agronomic value succeeded for 2 of 5 treated varieties. All these mutants showed a reduction in yield potential. One mutant showed partial resistance to S. nodorum. The disease development on the leaves and the spikes of this mutant was much slower than on the original variety. The characteristics of this mutant are discussed in detail. The genetics of tolerance proved to be polygenic and additive, which has consequences on the breeding method. A good way of obtaining a stable system would be the combination of high tolerance and partial resistance in the same cultivar. (author)

  10. Agronomic performance of rape seed (brassica napus L.) mutant lines under drought conditions

    International Nuclear Information System (INIS)

    Shah, S.A.; Ali, I.; Shah, S.J.A.; Rehman, K.; Rashid, A.

    1995-01-01

    Oil seed forms of Brassica napus are not well adapted to drought and the warner environments of Pakistan. Induced mutations were, therefore, utilized for improving drought tolerance efficiency of two napus cultivars. Induction of genetic variability, selection of desirable mutants and stabilization of mutants in acceptable agronomic background were carried out during 1988-1991. Fourteen promising mutants each of cv. Pak-cheen and Tower were evaluated for different agronomic characters in separate yield trials, under extremely drought conditions. The results demonstrated that yield potential of some mutants was very high and 9 mutants of cv. Pak-cheen and 8 mutants of cv. Tower significantly (P<0.05) out yield the local commercial cultivar. Eleven mutants in both the trials matured significantly earlier than the check. Nevertheless, more extensive testing of the drought tolerant lines under diversified environs of the country will help confirm these findings. (author)

  11. Evaluation of short stature mutants of Basmati-370 for yield and grain quality characteristics

    International Nuclear Information System (INIS)

    Awan, M.A.; Ahmad, M.; Cheema, A.A.

    1982-01-01

    Three short stature mutants were induced in an indica rice cultivar by gamma irradiation. The mutants were assessed for their yielding ability and grain quality characteristics. All the mutants out yielded the parent variety, Basmati-370. The increase in yield of the mutants ranged from 19.37% to 29.66%. DM-2 gave the highest yield (3587.96 kg/ha) among the mutants. As regards physical, cooking and eating quality characteristics, there was no significant difference in water absorption, volume expansion ratios and stickiness among the mutants and Basmati-370. However, Basmati-370 was scored best for flavour as this variety had strong aroma as compared to its mutants which were scored for moderately strong aroma. (authors)

  12. Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Rodermel, Steven

    2015-11-16

    The immutans (im) variegation mutant of Arabidopsis is an ideal model to gain insight into factors that control chloroplast biogenesis. im defines the gene for PTOX, a plastoquinol terminal oxidase that participates in control of thylakoid redox. Here, we report that the im defect can be suppressed during the late stages of plant development by gigantea (gi2), which defines the gene for GIGANTEA (GI), a central component of the circadian clock that plays a poorly-understood role in diverse plant developmental processes. imgi2 mutants are late-flowering and display other well-known phenotypes associated with gi2, such as starch accumulation and resistance to oxidative stress. We show that the restoration of chloroplast biogenesis in imgi2 is caused by a developmental-specific de-repression of cytokinin signaling that involves crosstalk with signaling pathways mediated by gibberellin (GA) and SPINDLY (SPY), a GA response inhibitor. Suppression of the plastid defect in imgi2 is likely caused by a relaxation of excitation pressures in developing plastids by factors contributed by gi2, including enhanced rates of photosynthesis and increased resistance to oxidative stress. Interestingly, the suppression phenotype of imgi can be mimicked by crossing im with the starch accumulation mutant, sex1, perhaps because sex1 utilizes pathways similar to gi. We conclude that our studies provide a direct genetic linkage between GIGANTEA and chloroplast biogenesis, and we construct a model of interactions between signaling pathways mediated by gi, GA, SPY, cytokinins, and sex1 that are required for chloroplast biogenesis.

  13. Rubisco mutants of Chlamydomonas reinhardtii enhance photosynthetic hydrogen production.

    Science.gov (United States)

    Pinto, T S; Malcata, F X; Arrabaça, J D; Silva, J M; Spreitzer, R J; Esquível, M G

    2013-06-01

    Molecular hydrogen (H2) is an ideal fuel characterized by high enthalpy change and lack of greenhouse effects. This biofuel can be released by microalgae via reduction of protons to molecular hydrogen catalyzed by hydrogenases. The main competitor for the reducing power required by the hydrogenases is the Calvin cycle, and rubisco plays a key role therein. Engineered Chlamydomonas with reduced rubisco levels, activity and stability was used as the basis of this research effort aimed at increasing hydrogen production. Biochemical monitoring in such metabolically engineered mutant cells proceeded in Tris/acetate/phosphate culture medium with S-depletion or repletion, both under hypoxia. Photosynthetic activity, maximum photochemical efficiency, chlorophyll and protein levels were all measured. In addition, expression of rubisco, hydrogenase, D1 and Lhcb were investigated, and H2 was quantified. At the beginning of the experiments, rubisco increased followed by intense degradation. Lhcb proteins exhibited monomeric isoforms during the first 24 to 48 h, and D1 displayed sensitivity under S-depletion. Rubisco mutants exhibited a significant decrease in O2 evolution compared with the control. Although the S-depleted medium was much more suitable than its complete counterpart for H2 production, hydrogen release was observed also in sealed S-repleted cultures of rubisco mutated cells under low-moderate light conditions. In particular, the rubisco mutant Y67A accounted for 10-15-fold higher hydrogen production than the wild type under the same conditions and also displayed divergent metabolic parameters. These results indicate that rubisco is a promising target for improving hydrogen production rates in engineered microalgae.

  14. Stress-tolerant mutants induced by heavy-ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Tomoko; Yoshida, Shigeo [Institute of Physical and Chemical Research, Wako, Saitama (Japan); Bae, Chang-Hyu [Sunchon National University, Sunchon (Korea); Ozaki, Takuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Wang, Jing Ming [Akita Prefectural Univ. (Japan)

    2000-07-01

    Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M{sub 1} seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M{sub 3} progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to {sup 14}N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M{sub 1} progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M{sub 1} seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

  15. Stress-tolerant mutants induced by heavy-ion beams

    International Nuclear Information System (INIS)

    Abe, Tomoko; Yoshida, Shigeo; Bae, Chang-Hyu; Ozaki, Takuo

    2000-01-01

    Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M 1 seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M 3 progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to 14 N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M 1 progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M 1 seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

  16. Mutant IDH1 Promotes Glioma Formation In Vivo

    Directory of Open Access Journals (Sweden)

    Beatrice Philip

    2018-05-01

    Full Text Available Summary: Isocitrate dehydrogenase 1 (IDH1 is the most commonly mutated gene in grade II–III glioma and secondary glioblastoma (GBM. A causal role for IDH1R132H in gliomagenesis has been proposed, but functional validation in vivo has not been demonstrated. In this study, we assessed the role of IDH1R132H in glioma development in the context of clinically relevant cooperating genetic alterations in vitro and in vivo. Immortal astrocytes expressing IDH1R132H exhibited elevated (R-2-hydroxyglutarate levels, reduced NADPH, increased proliferation, and anchorage-independent growth. Although not sufficient on its own, IDH1R132H cooperated with PDGFA and loss of Cdkn2a, Atrx, and Pten to promote glioma development in vivo. These tumors resembled proneural human mutant IDH1 GBM genetically, histologically, and functionally. Our findings support the hypothesis that IDH1R132H promotes glioma development. This model enhances our understanding of the biology of IDH1R132H-driven gliomas and facilitates testing of therapeutic strategies designed to combat this deadly disease. : Philip et al. show that mutant IDH1 cooperates with PDGFA and loss of Cdkn2a, Atrx, and Pten to promote gliomagenesis in vivo in a mouse model of glioma. These tumors resemble proneural human mutant IDH1 glioblastoma and exhibit enhanced sensitivity to PARP inhibition in combination with chemotherapy. Keywords: IDH1, Cdkn2a, Atrx, Pten, glioma, mouse model, RCAS/TVA

  17. Masking responses to light in period mutant mice.

    Science.gov (United States)

    Pendergast, Julie S; Yamazaki, Shin

    2011-10-01

    Masking is an acute effect of an external signal on an overt rhythm and is distinct from the process of entrainment. In the current study, we investigated the phase dependence and molecular mechanisms regulating masking effects of light pulses on spontaneous locomotor activity in mice. The circadian genes, Period1 (Per1) and Per2, are necessary components of the timekeeping machinery and entrainment by light appears to involve the induction of the expression of Per1 and Per2 mRNAs in the suprachiasmatic nuclei (SCN). We assessed the roles of the Per genes in regulating masking by assessing the effects of light pulses on nocturnal locomotor activity in C57BL/6J Per mutant mice. We found that Per1(-/-) and Per2(-/-) mice had robust negative masking responses to light. In addition, the locomotor activity of Per1(-/-)/Per2(-/-) mice appeared to be rhythmic in the light-dark (LD) cycle, and the phase of activity onset was advanced (but varied among individual mice) relative to lights off. This rhythm persisted for 1 to 2 days in constant darkness in some Per1(-/-)/Per2(-/-) mice. Furthermore, Per1(-/-)/Per2(-/-) mice exhibited robust negative masking responses to light. Negative masking was phase dependent in wild-type mice such that maximal suppression was induced by light pulses at zeitgeber time 14 (ZT14) and gradually weaker suppression occurred during light pulses at ZT16 and ZT18. By measuring the phase shifts induced by the masking protocol (light pulses were administered to mice maintained in the LD cycle), we found that the phase responsiveness of Per mutant mice was altered compared to wild-types. Together, our data suggest that negative masking responses to light are robust in Per mutant mice and that the Per1(-/-)/Per2(-/-) SCN may be a light-driven, weak/damping oscillator.

  18. Genetic study on salt tolerance involving mutants of barley

    International Nuclear Information System (INIS)

    Patil, S.S.; Sharma, R.P.

    1990-01-01

    Full text: Cultivar 'R-16' was subjected to mutagenesis through gamma irradiation, EMS and their combination treatments. M 6 lines differing in salt tolerance were utilised along with untreated control to generate 8x3 diallel crosses. The magnitude of combining ability variances indicated a relatively prominent role of SCA variance (non additive). The values of GCA effects indicate high breeding value of the mutant M-3 for salt tolerance based on measuring shoot length and root length of 10 day old seedlings. (author)

  19. Ultra-violet-resistant mutants of Bacillus thuringiensis

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D R; Karunakaran, V [Polytechnic of Central London (UK). Faculty of Engineering and Science, School of Biological and Health Sciences; Burges, H D [Institute of Horticultural Research, Littlehampton (UK); Hacking, A J [Reading Univ. (UK). Dextra Labs.Ltd.

    1991-06-01

    One of the main disadvantages of using Bacillus thuringiensis as an insecticide is that the spore and crystal preparations applied to foliage are readily washed away by rain and are inactivated by sunlight. Spores from some strains of B. thuringiensis have been shown to be highly sensitive to u.v. light. This study has demonstrated how mutants with increased resistance to u.v., isolated by successive rounds of u.v. irradiation, and additionally with increased specific pathogenicity can be isolated. These techniques should be applied to strains that are frequently used in the industrial production of B.thuringiensis toxin. (author).

  20. Ultra-violet-resistant mutants of Bacillus thuringiensis

    International Nuclear Information System (INIS)

    Jones, D.R.; Karunakaran, V.; Hacking, A.J.

    1991-01-01

    One of the main disadvantages of using Bacillus thuringiensis as an insecticide is that the spore and crystal preparations applied to foliage are readily washed away by rain and are inactivated by sunlight. Spores from some strains of B. thuringiensis have been shown to be highly sensitive to u.v. light. This study has demonstrated how mutants with increased resistance to u.v., isolated by successive rounds of u.v. irradiation, and additionally with increased specific pathogenicity can be isolated. These techniques should be applied to strains that are frequently used in the industrial production of B.thuringiensis toxin. (author)

  1. Genetic analysis of rice semidwarf mutant Tad-M-1

    International Nuclear Information System (INIS)

    Wang Naiyuan; Yang Rencui

    1995-01-01

    This paper dealed with the inheritance of the rice semidwarf of Tad-M-,a mutant line bred from traditional indica rice Variety Tadukan by radiation. The results indicated that semidwarf of Tad-M-1 was controlled by one pair of recessive gene, which was nonallelic to sd-1 gene of variety Aijiaonante and sd-g gene of variety Xinguiai and allelic to the semidwarf gene of Yunnan japonica variety Xueheaizao and Sichuan indica variety Yizila.The possible uses of Tad-M-1 in rice breeding was also discussed

  2. Characterization of Foliage Mutants for Plant Variety Registration

    International Nuclear Information System (INIS)

    Affrida Abu Hassan; Shuhaimi Shamsuddin; Zaiton Ahmad

    2011-01-01

    Breeding for new plant varieties requires a substantial investment in terms of skill, labour, material resources and financing. Thus, registration of new plant variety is important to ensure return of revenue and protection of the breeder's right. Before a new variety is registered, it has to comply certain requirements under Plant Variety Protection Act. One of the most important requirements is, the new species/variety must be morphologically distinguishable from existing plant varieties. This paper discusses detailed leaf characteristics of 4 foliage mutants produced by Malaysian Nuclear Agency as part of the requirement for new variety registration. (author)

  3. Assessment of TS-1, a thick cane mutant

    International Nuclear Information System (INIS)

    Shama Rao, H.K.

    1979-01-01

    A true breeding thick cane mutant TS-1, induced by radiations, was obtained in variety Co-419. TS-1 was found to be superior to Co-419 with respect to cane size, weight, yield and juice quality. The thick canes of TS-1 were found to be solid even at 14 months age and so also their ratoons. The tillering habit of TS-1 has a definite advantage over other varieties with respect to easy intercultural field operations. TS-1 is now being tested under various agroclimatic zones in Karnataka, Maharashtra and U.P. (auth.)

  4. Reverse genetics in Chlamydomonas: a platform for isolating insertional mutants

    Directory of Open Access Journals (Sweden)

    de Montaigu Amaury

    2011-07-01

    Full Text Available Abstract A method was developed to identify insertional mutants of Chlamydomonas reinhardtii disrupted for selected target genes. The approach relies on the generation of thousands of transformants followed by PCR-based screenings that allow for identification of strains harboring the introduced marker gene within specific genes of interest. Our results highlight the strengths and limitations of two independent screens that differed in the nature of the marker DNA used (PCR-amplified fragment containing the plasmid-free marker versus entire linearized plasmid with the marker and in the strategies used to maintain and store transformants.

  5. Using PATIMDB to create bacterial transposon insertion mutant libraries.

    Science.gov (United States)

    Urbach, Jonathan M; Wei, Tao; Liberati, Nicole; Grenfell-Lee, Daniel; Villanueva, Jacinto; Wu, Gang; Ausubel, Frederick M

    2009-04-01

    PATIMDB is a software package for facilitating the generation of transposon mutant insertion libraries. The software has two main functions: process tracking and automated sequence analysis. The process tracking function specifically includes recording the status and fates of multiwell plates and samples in various stages of library construction. Automated sequence analysis refers specifically to the pipeline of sequence analysis starting with ABI files from a sequencing facility and ending with insertion location identifications. The protocols in this unit describe installation and use of PATIMDB software.

  6. Probing the mechanism of insulin fibril formation with insulin mutants.

    Science.gov (United States)

    Nielsen, L; Frokjaer, S; Brange, J; Uversky, V N; Fink, A L

    2001-07-27

    The molecular basis of insulin fibril formation was investigated by studying the structural properties and kinetics of fibril formation of 20 different human insulin mutants at both low pH (conditions favoring monomer/dimer) and at pH 7.4 (conditions favoring tetramer/hexamer). Small-angle X-ray scattering showed insulin to be monomeric in 20% acetic acid, 0.1 M NaCl, pH 2. The secondary structure of the mutants was assessed using far-UV circular dichroism, and the tertiary structure was determined using near-UV circular dichroism, quenching of intrinsic fluorescence by acrylamide and interactions with the hydrophobic probe 1-anilino-8-naphthalene-sulfonic acid (ANS). The kinetics of fibril formation were monitored with the fluorescent dye, Thioflavin T. The results indicate that the monomer is the state from which fibrils arise, thus under some conditions dissociation of hexamers may be rate limiting or partially rate limiting. The insulin mutants were found to retain substantial nativelike secondary and tertiary structure under all conditions studied. The results suggest that fibril formation of the insulin mutants is controlled by specific molecular interactions that are sensitive to variations in the primary structure. The observed effects of several mutations on the rate of fibril formation are inconsistent with a previously suggested model for fibrillation [Brange, J., Whittingham, J., Edwards, D., Youshang, Z., Wollmer, A., Brandenburg, D., Dodson, G., and Finch, J. (1997) Curr. Sci. 72, 470-476]. Two surfaces on the insulin monomer are identified as potential interacting sites in insulin fibrils, one consisting of the residues B10, B16, and B17 and the other consisting of at least the residues A8 and B25. The marked increase in the lag time for fibril formation with mutations to more polar residues, as well as mutations to charged residues, demonstrates the importance of both hydrophobic and electrostatic interactions in the initial stages of fibrillation

  7. Preliminary Study of the Characteristics of Several Glossy Cabbage (Brassica oleracea var. capitata L. Mutants

    Directory of Open Access Journals (Sweden)

    Tang Jun

    2015-09-01

    Full Text Available To determine the characteristics and potential practical applications of glossy cabbage (Brassica oleracea var. capitata L. mutants, five different glossy mutants were studied. The amount of epicuticular wax covering the mutant leaves was only approximately 30% that of the wild-type (WT leaves. The wax crystals of WT plants were columnar and linear, while they were granular and rod-shaped in the mutants. Additionally, in WT cabbage, the primary wax components were alkanes, alcohols, fatty acids, ketones, and aldehydes. There was a significant decrease in the abundance of alkanes and ketones in the wax of the mutants. The glossy-green trait of the mutants may be the result of an inhibited alkane-forming pathway. Higher rates of chlorophyll leaching and water loss demonstrate that the mutant leaves were more permeable and sensitive to drought stress than the WT leaves. Growth curve results indicated that the growth rate of mutant-1 and mutant-3 was slower than that of the corresponding WT cabbage, resulting in shorter plants. However, the growth rate of mutant-2 was not influenced by the lack of coating wax. An investigation of the agronomic traits and heterosis of the glossy cabbage mutants indicated that all five mutants had glossy-green leaves, which was a favorable characteristic. The F1 plants derived from crosses involving mutant-2 exhibited obvious heterosis, suggesting the observed glossy-green trait is controlled by a dominant gene. Therefore, mutant-2 may be useful as a source of genetic material for future cabbage breeding experiments.

  8. Characterization of three Agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.

    Science.gov (United States)

    Metts, J; West, J; Doares, S H; Matthysse, A G

    1991-02-01

    Three Agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. Two of the mutants were avirulent on all hosts tested. The third mutant, Ivr-211, was a host range mutant which was avirulent on Bryophyllum diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and Daucus carota but was virulent on Zinnia elegans and Lycopersicon esculentum (tomato). That the mutant phenotype was due to the transposon insertion was determined by cloning the DNA containing the transposon insertion and using the cloned DNA to replace the wild-type DNA in the parent bacterial strain by marker exchange. The transposon insertions in the three mutants mapped at three widely separated locations on the bacterial chromosome. The effects of the mutations on various steps in tumor formation were examined. All three mutants showed no alteration in binding to carrot cells. However, none of the mutants showed any induction of vir genes by acetosyringone under conditions in which the parent strain showed vir gene induction. When the mutant bacteria were examined for changes in surface components, it was found that all three of the mutants showed a similar alteration in lipopolysaccharide (LPS). LPS from the mutants was larger in size and more heavily saccharide substituted than LPS from the parent strain. Two of the mutants showed no detectable alteration in outer membrane and periplasmic space proteins. The third mutant, Ivr-225, was missing a 79-kDa surface peptide. The reason(s) for the failure of vir gene induction in these mutants and its relationship, if any, to the observed alteration in LPS are unknown.

  9. AFM images of complexes between amylose and Aspergillus niger glucoamylase mutants, native and mutant starch binding domains: a model for the action of glucoamylase

    DEFF Research Database (Denmark)

    Morris, V. M.; Gunning, A. P.; Faults, C. B.

    2005-01-01

    Atomic force microscopy has been used to investigate the complexes formed between high molecular weight amylose chains and Aspergillus niger glucoamylase mutants (E400Q and W52F), wild-type A. niger starch binding domains (SBDS), and mutant SBDs (W563K and W590K) lacking either of the two starch...

  10. Overexpression of SOS genes in ciprofloxacin resistant Escherichia coli mutants.

    Science.gov (United States)

    Pourahmad Jaktaji, Razieh; Pasand, Shirin

    2016-01-15

    Fluoroquinolones are important antibiotics for the treatment of urinary tract infections caused by Escherichia coli. Mutational studies have shown that ciprofloxacin, a member of fluoroquinolones induces SOS response and mutagenesis in pathogenic bacteria which in turn develop antibiotic resistance. However, inhibition of SOS response can increase recombination activity which in turn leads to genetic variation. The aim of this study was to measure 5 SOS genes expressions in nine E. coli mutants with different MICs for ciprofloxacin following exposure to ciprofloxacin. Gene expression was assessed by quantitative real time PCR. Gene alteration assessment was conducted by PCR amplification and DNA sequencing. Results showed that the expression of recA was increased in 5 mutants. This overexpression is not related to gene alteration, and enhances the expression of polB and umuCD genes encoding nonmutagenic and mutagenic polymerases, respectively. The direct relationship between the level of SOS expression and the level of resistance to ciprofloxacin was also indicated. It was concluded that novel therapeutic strategy that inhibits RecA activity would enhance the efficiency of common antibiotics against pathogenic bacteria. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Increased somatic cell mutant frequency in atomic bomb survivors

    International Nuclear Information System (INIS)

    Hakoda, Masayuki; Akiyama, Mitoshi; Kyoizumi, Seishi; Awa, A.A.; Yamakido, Michio; Otake, Masanori.

    1988-05-01

    Frequencies of mutant T-cells in peripheral blood, which are deficient in the activity of hypoxanthine guanine phosphoribosyltransferase (HPRT) were determined for atomic bomb survivors by direct clonal assay using a previously reported method. Results from 30 exposed survivors (exposed to more than 1 rad) and 17 age- and sex-matched controls (exposed to less than 1 rad) were analyzed. The mean mutant frequency (Mf) in the exposed (5.2 x 10 -6 ; range 0.8 - 14.4 x 10 -6 ) was significantly higher than in controls (3.4 x 10 -6 ; range 1.3 - 9.3 x 10 -6 ), a fact not attributable to lower nonmutant cell cloning efficiencies in the exposed group since cell cloning efficiencies were virtually identical in both groups. An initial analysis of the data did not reveal a significant correlation between individual Mfs and individual radiation dose estimates when the latter were defined by the original, tentative estimates (T65D), even though there was a significant positive correlation of Mfs with individual frequency of lymphocytes bearing chromosome aberration. However, reanalysis using the newer revised individual dose estimates (DS86) for 27 exposed survivors and 17 controls did reveal a significant but shallow positive correlation between T-cell Mf values and individual exposure doses. These results indicate that HPRT mutation in vivo in human T-cells could be detected in these survivors 40 years after the presumed mutational event. (author)

  12. Computational identification of adaptive mutants using the VERT system

    Directory of Open Access Journals (Sweden)

    Winkler James

    2012-04-01

    Full Text Available Background Evolutionary dynamics of microbial organisms can now be visualized using the Visualizing Evolution in Real Time (VERT system, in which several isogenic strains expressing different fluorescent proteins compete during adaptive evolution and are tracked using fluorescent cell sorting to construct a population history over time. Mutations conferring enhanced growth rates can be detected by observing changes in the fluorescent population proportions. Results Using data obtained from several VERT experiments, we construct a hidden Markov-derived model to detect these adaptive events in VERT experiments without external intervention beyond initial training. Analysis of annotated data revealed that the model achieves consensus with human annotation for 85-93% of the data points when detecting adaptive events. A method to determine the optimal time point to isolate adaptive mutants is also introduced. Conclusions The developed model offers a new way to monitor adaptive evolution experiments without the need for external intervention, thereby simplifying adaptive evolution efforts relying on population tracking. Future efforts to construct a fully automated system to isolate adaptive mutants may find the algorithm a useful tool.

  13. Search for C4 developmental mutants in Panicum maximum Jacq

    International Nuclear Information System (INIS)

    Fladung, M.

    2001-01-01

    Full text: Mutant plants are useful tools for studying developmental processes in defined genetic backgrounds by comparing them with their respective wild type forms. In this sense, developmental mutants or mutations involved in the establishment of certain leaf or flower specific traits are of special interest. In particular, the evolution of C 4 photosynthesis from C 3 precursors was accompanied by severe developmental changes in leaf morphology and anatomy. Our search of such mutants was followed by the idea to approach the evolution of the C 4 syndrome from a mutagenic point of view. Variants affecting normal development of the C 4 leaf anatomy may, in fact, represent possible regressive steps in C4 photosynthesis. Seeds of the C4 grass Panicum maximum Jacq. were mutagenized using ethylmethanesulfonate (EMS) and putative variants were isolated in the M2 generation by visual inspection. Main selection characteristics were whole plant, leaf morphology and pigmentation, and growth characteristics. The choice of a polyploid species for mutagenesis experiments was based on the need of detecting rare mutants, which are possibly lethal when using a diploid plant species. These variants could be of regulatory nature, affecting both morphology and physiology of C 4 photosynthesis early in leaf development. In total, nearly 100 variants were isolated and grown to maturity. Main isolated variants, which conforms to the prediction mentioned above, were as following: large interveinal space-1 and -3 (lis1, lis3), abnormal bundle sheath (abs), midribless (mbl) and variegated leaf -1 (var1). The variant lis1 was a short plant with leaves smaller than the wild type, and had a leaf lamina with a crinkly surface. Photosynthetically, lis1 indicates a clear regression from the C 4 to the C 3 photosynthesis type, which was correlated in the leaf lamina with an increase in the distance between small veins. The variant lis3 was not similar phenotypically to lis1, but it also had very

  14. Nonselective enrichment for yeast adenine mutants by flow cytometry

    Science.gov (United States)

    Bruschi, C. V.; Chuba, P. J.

    1988-01-01

    The expression of certain adenine biosynthetic mutations in the yeast Saccharomyces cerevisiae results in a red colony color. This phenomenon has historically provided an ideal genetic marker for the study of mutation, recombination, and aneuploidy in lower eukaryotes by classical genetic analysis. In this paper, it is reported that cells carrying ade1 and/or ade2 mutations exhibit primary fluorescence. Based on this observation, the nonselective enrichment of yeast cultures for viable adenine mutants by using the fluorescence-activated cell sorter has been achieved. The advantages of this approach over conventional genetic analysis of mutation, recombination, and mitotic chromosomal stability include speed and accuracy in acquiring data for large numbers of clones. By using appropriate strains, the cell sorter has been used for the isolation of both forward mutations and chromosomal loss events in S. cerevisiae. The resolving power of this system and its noninvasiveness can easily be extended to more complex organisms, including mammalian cells, in which analogous metabolic mutants are available.

  15. Flavonoid accumulation patterns of transparent testa mutants of arabidopsis

    Science.gov (United States)

    Peer, W. A.; Brown, D. E.; Tague, B. W.; Muday, G. K.; Taiz, L.; Murphy, A. S.

    2001-01-01

    Flavonoids have been implicated in the regulation of auxin movements in Arabidopsis. To understand when and where flavonoids may be acting to control auxin movement, the flavonoid accumulation pattern was examined in young seedlings and mature tissues of wild-type Arabidopsis. Using a variety of biochemical and visualization techniques, flavonoid accumulation in mature plants was localized in cauline leaves, pollen, stigmata, and floral primordia, and in the stems of young, actively growing inflorescences. In young Landsberg erecta seedlings, aglycone flavonols accumulated developmentally in three regions, the cotyledonary node, the hypocotyl-root transition zone, and the root tip. Aglycone flavonols accumulated at the hypocotyl-root transition zone in a developmental and tissue-specific manner with kaempferol in the epidermis and quercetin in the cortex. Quercetin localized subcellularly in the nuclear region, plasma membrane, and endomembrane system, whereas kaempferol localized in the nuclear region and plasma membrane. The flavonoid accumulation pattern was also examined in transparent testa mutants blocked at different steps in the flavonoid biosynthesis pathway. The transparent testa mutants were shown to have precursor accumulation patterns similar to those of end product flavonoids in wild-type Landsberg erecta, suggesting that synthesis and end product accumulation occur in the same cells.

  16. Identification and Characterization of Spontaneous Auxotrophic Mutants in Fusarium langsethiae

    Directory of Open Access Journals (Sweden)

    Olga Gavrilova

    2017-03-01

    Full Text Available Analysis of 49 strains of Fusarium langsethiae originating from northern Europe (Russia, Finland, Sweden, UK, Norway, and Latvia revealed the presence of spontaneous auxotrophic mutants that reflect natural intraspecific diversity. Our investigations detected that 49.0% of F. langsethiae strains were auxotrophic mutants for biotin, and 8.2% of the strains required thiamine as a growth factor. They failed to grow on vitamin-free media. For both prototrophic and auxotrophic strains, no growth defect was observed in rich organic media. Without essential vitamins, a significant reduction in the growth of the auxotrophic strains results in a decrease of the formation of T-2 toxin and diacetoxyscirpenol. In addition, all analysed F. langsethiae strains were distinguished into two subgroups based on PCR product sizes. According to our results, 26 and 23 strains of F. langsethiae belong to subgroups I and II respectively. We determined that the deletion in the intergenic spacer (IGS region of the rDNA of F. langsethiae belonging to subgroup II is linked with temperature sensitivity and causes a decrease in strain growth at 30 °C. Four thiamine auxotrophic strains were found in subgroup I, while 21 biotin auxotrophic strains were detected in subgroups II. To the best of our knowledge, the spontaneous mutations in F. langsethiae observed in the present work have not been previously reported.

  17. Analysis of Stomatal Patterning in Selected Mutants of MAPK Pathways

    KAUST Repository

    Felemban, Abrar

    2016-05-01

    Stomata are cellular valves in plants that play an essential role in the regulation of gas exchange and are distributed in the epidermis of aerial organs. In Arabidopsis thaliana, stomatal production and development are coordinated by the mitogen-activated protein kinase (MAPK) signalling pathway, which modulates a variety of other processes, including cell proliferation, regulation of cytokinesis, programed cell death, and response to abiotic and biotic stress. The environment also plays a role in stomatal development, by influencing the frequency at which stomata develop in leaves. This thesis presents an analysis of stomatal development in Arabidopsis mutants in two MAPK pathways: MEKK1-MKK1/MKK2-MPK4, and MAP3K17/18-MKK3. Obtained results demonstrate the effect of stress conditions on stomatal development and specify the involvement of analysed MAPK in stomatal patterning. First, both analysed pathways modulate stomatal patterning in Arabidopsis cotyledons. Second, plant growth-promoting bacteria tested enhance stomatal density and affect guard cell morphology. Third, the sucrose or mannitol treatment increases defects in stomatal patterning. Finally, salt stress or high temperature can suppress stomatal defects in mutants of the MEKK1-MKK1/MKK2-MPK4 pathway.

  18. Establishment of Homozygote Mutant Human Embryonic Stem Cells by Parthenogenesis.

    Science.gov (United States)

    Epsztejn-Litman, Silvina; Cohen-Hadad, Yaara; Aharoni, Shira; Altarescu, Gheona; Renbaum, Paul; Levy-Lahad, Ephrat; Schonberger, Oshrat; Eldar-Geva, Talia; Zeligson, Sharon; Eiges, Rachel

    2015-01-01

    We report on the derivation of a diploid 46(XX) human embryonic stem cell (HESC) line that is homozygous for the common deletion associated with Spinal muscular atrophy type 1 (SMA) from a pathenogenetic embryo. By characterizing the methylation status of three different imprinted loci (MEST, SNRPN and H19), monitoring the expression of two parentally imprinted genes (SNRPN and H19) and carrying out genome-wide SNP analysis, we provide evidence that this cell line was established from the activation of a mutant oocyte by diploidization of the entire genome. Therefore, our SMA parthenogenetic HESC (pHESC) line provides a proof-of-principle for the establishment of diseased HESC lines without the need for gene manipulation. As mutant oocytes are easily obtained and readily available during preimplantation genetic diagnosis (PGD) cycles, this approach should provide a powerful tool for disease modelling and is especially advantageous since it can be used to induce large or complex mutations in HESCs, including gross DNA alterations and chromosomal rearrangements, which are otherwise hard to achieve.

  19. Establishment of Homozygote Mutant Human Embryonic Stem Cells by Parthenogenesis.

    Directory of Open Access Journals (Sweden)

    Silvina Epsztejn-Litman

    Full Text Available We report on the derivation of a diploid 46(XX human embryonic stem cell (HESC line that is homozygous for the common deletion associated with Spinal muscular atrophy type 1 (SMA from a pathenogenetic embryo. By characterizing the methylation status of three different imprinted loci (MEST, SNRPN and H19, monitoring the expression of two parentally imprinted genes (SNRPN and H19 and carrying out genome-wide SNP analysis, we provide evidence that this cell line was established from the activation of a mutant oocyte by diploidization of the entire genome. Therefore, our SMA parthenogenetic HESC (pHESC line provides a proof-of-principle for the establishment of diseased HESC lines without the need for gene manipulation. As mutant oocytes are easily obtained and readily available during preimplantation genetic diagnosis (PGD cycles, this approach should provide a powerful tool for disease modelling and is especially advantageous since it can be used to induce large or complex mutations in HESCs, including gross DNA alterations and chromosomal rearrangements, which are otherwise hard to achieve.

  20. Structural dataset for the PPARγ V290M mutant

    Directory of Open Access Journals (Sweden)

    Ana C. Puhl

    2016-06-01

    Full Text Available Loss-of-function mutation V290M in the ligand-binding domain of the peroxisome proliferator activated receptor γ (PPARγ is associated with a ligand resistance syndrome (PLRS, characterized by partial lipodystrophy and severe insulin resistance. In this data article we discuss an X-ray diffraction dataset that yielded the structure of PPARγ LBD V290M mutant refined at 2.3 Å resolution, that allowed building of 3D model of the receptor mutant with high confidence and revealed continuous well-defined electron density for the partial agonist diclofenac bound to hydrophobic pocket of the PPARγ. These structural data provide significant insights into molecular basis of PLRS caused by V290M mutation and are correlated with the receptor disability of rosiglitazone binding and increased affinity for corepressors. Furthermore, our structural evidence helps to explain clinical observations which point out to a failure to restore receptor function by the treatment with a full agonist of PPARγ, rosiglitazone.

  1. Analysis of Arabidopsis mutants deficient in flavonoid biosynthesis

    International Nuclear Information System (INIS)

    Shirley, B.W.; Kubasek, W.L.; Storz, G.; Bruggemann, E.; Koornneef, M.; Ausubel, F.M.; Goodman, H.M.

    1995-01-01

    Eleven loci that play a role in the synthesis of flavonoids in Arabidopsis are described. Mutations at these loci, collectively named transparent testa (tt), disrupt the synthesis of brown pigments in the seed coat (testa). Several of these loci (tt3, tt4, tt5 and ttg) are also required for the accumulation of purple anthocyanins in leaves and stems and one locus (ttg) plays additional roles in trichome and root hair development. Specific functions were previously assigned to tt1-7 and ttg. Here, the results of additional genetic, biochemical and molecular analyses of these mutants are described. Genetic map positions were determined for tt8, tt9 and tt10. Thin-layer chromatography identified tissue- and locus-specific differences in the flavonols and anthocyanidins synthesized by mutant and wild-type plants. It was found that UV light reveals distinct differences in the floral tissues of tt3, tt4, tt5, tt6 and ttg, even though these tissues are indistinguishable under visible light. Evidence was also uncovered that tt8 and ttg specifically affect dihydroflavonol reductase gene expression. A summary of these and previously published results are incorporated into an overview of the genetics of flavonoid biosynthesis in Arabidopsis

  2. Studies on radiation induced morphological mutants in Sesamum orientale (L)

    International Nuclear Information System (INIS)

    Nayar, G.G.

    1970-01-01

    The agronomic characters of four X-ray induced morphological mutants in S. orientale L. viz. WFM, SSM isolated from var. T16 (back seeded) and SSM 2 and Chlo.mut.isolated from var. T10 (brown seeded) were studied. WFM, SSM and SSM 2 showed early sprouting and increased growth while the Chlo.mut. showed delayed germination and growth. The mean leaf size, plant height and number of branches were greater in WFM and SSM as compared to T16. The mean time of flowering was early in SSM and SSM 2 while it was late in WFM and the Chol.mut. as against their respective parents; the differences were significant. In mean yield of fruits per plant, WFM and SSM were superior to T16. A large scale trial has indicated that the seed yield in the mutants WFM, SSM and SSM 2 was slightly higher than their parents. WFM, SSM and SSM 2 showed an increase in oil content, the increase in SSM and SSM 2 being 6 to 10 percent. The quality of oil as indicated by colour and peroxide value (keeping quality) was also superior in WFM and SSM. The development of three flowers per node in SSM (otherwise solitary and axillary), two from modified nectary glands on either side of the leaf, provides some information on the phylogeny of the nectary glands and would appear to be of some economic significance. (author)

  3. Flavonol-induced changes in PIN2 polarity and auxin transport in the Arabidopsis thaliana rol1-2 mutant require phosphatase activity

    Czech Academy of Sciences Publication Activity Database

    Kuhn, B.M.; Nodzynski, T.; Errafi, S.; Bucher, R.; Gupta, S.; Aryal, B.; Dobrev, Petre; Bigler, L.; Geisler, M.; Zažímalová, Eva; Friml, J.; Ringli, Ch.

    2017-01-01

    Roč. 7, FEB 6 (2017), č. článku 41906. ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LQ1601; GA ČR(CZ) GA16-10948S Institutional support: RVO:61389030 Keywords : regulatory subunit * p-glycoproteins * lateral root * protein * efflux * phosphorylation * growth * accumulation * gravitropism * mutation Subject RIV: CE - Biochemistry OBOR OECD: Cell biology Impact factor: 4.259, year: 2016

  4. Genetic analyses of nonfluorescent root mutants induced by mutagenesis in soybean

    International Nuclear Information System (INIS)

    Sawada, S.; Palmer, R.G.

    1987-01-01

    Nonfluorescent root mutants in soybean [Glycine max (L.) Merr.] are useful as markers in genetic studies and in tissue culture research. Our objective was to obtain mutagen-induced nonfluorescent root mutants and to conduct genetic studies with them. Thirteen nonfluorescent mutants were detected among 154016 seedlings derived from soybean lines treated with six mutagens. One of these mutants, derived from Williams treated with 20 kR gamma rays, did not correspond to any of the known (standard) nonfluorescent spontaneous mutants. This is the first mutagen-induced nonfluorescent root mutant in soybean. It was assigned Genetic Type Collection no. T285 and the gene symbol fr5 fr5. The fr5 allele was not located on trisomics A, B, or C and was not linked to five chlorophyll-deficient mutants (y9, y11, y12, y13, and y20-k2) or flower color mutant w1. The remaining nonfluorescent root mutants were at the same loci as known spontaneous mutants; i.e., four had the fr1 allele, five had the fr2 allele, and three had the fr4 allele

  5. Defining the requirements for the pathogenic interaction between mutant calreticulin and MPL in MPN.

    Science.gov (United States)

    Elf, Shannon; Abdelfattah, Nouran S; Baral, April J; Beeson, Danielle; Rivera, Jeanne F; Ko, Amy; Florescu, Natalie; Birrane, Gabriel; Chen, Edwin; Mullally, Ann

    2018-02-15

    Mutations in calreticulin ( CALR ) are phenotypic drivers in the pathogenesis of myeloproliferative neoplasms. Mechanistic studies have demonstrated that mutant CALR binds to the thrombopoietin receptor MPL, and that the positive electrostatic charge of the mutant CALR C terminus is required for mutant CALR-mediated activation of JAK-STAT signaling. Here we demonstrate that although binding between mutant CALR and MPL is required for mutant CALR to transform hematopoietic cells; binding alone is insufficient for cytokine independent growth. We further show that the threshold of positive charge in the mutant CALR C terminus influences both binding of mutant CALR to MPL and activation of MPL signaling. We find that mutant CALR binds to the extracellular domain of MPL and that 3 tyrosine residues within the intracellular domain of MPL are required to activate signaling. With respect to mutant CALR function, we show that its lectin-dependent function is required for binding to MPL and for cytokine independent growth, whereas its chaperone and polypeptide-binding functionalities are dispensable. Together, our findings provide additional insights into the mechanism of the pathogenic mutant CALR-MPL interaction in myeloproliferative neoplasms. © 2018 by The American Society of Hematology.

  6. Exploring the regulatory role of isocitrate dehydrogenase mutant protein on glioma stem cell proliferation.

    Science.gov (United States)

    Lu, H-C; Ma, J; Zhuang, Z; Qiu, F; Cheng, H-L; Shi, J-X

    2016-08-01

    Glioma is the most lethal form of cancer that originates mostly from the brain and less frequently from the spine. Glioma is characterized by abnormal regulation of glial cell differentiation. The severity of the glioma was found to be relaxed in isocitrate dehydrogenase 1 (IDH1) mutant. The present study focused on histological discrimination and regulation of cancer stem cell between IDH1 mutant and in non-IDH1 mutant glioma tissue. Histology, immunohistochemistry and Western blotting techniques are used to analyze the glioma nature and variation in glioma stem cells that differ between IDH1 mutant and in non-IDH1 mutant glioma tissue. The aggressive form of non-IDH1 mutant glioma shows abnormal cellular histological variation with prominent larger nucleus along with abnormal clustering of cells. The longer survival form of IDH1 mutant glioma has a control over glioma stem cell proliferation. Immunohistochemistry with stem cell markers, CD133 and EGFRvIII are used to demonstrate that the IDH1 mutant glioma shows limited dependence on cancer stem cells and it shows marked apoptotic signals in TUNEL assay to regulate abnormal cells. The non-IDH1 mutant glioma failed to regulate misbehaving cells and it promotes cancer stem cell proliferation. Our finding supports that the IDH1 mutant glioma has a regulatory role in glioma stem cells and their survival.

  7. Isolation and characterization of X-linked mutants of Drosophila melanogaster which are sensitive to mutagens

    International Nuclear Information System (INIS)

    Boyd, J.B.; Golino, M.D.; Nguyen, T.D.; Green, M.M.

    1976-01-01

    Thirteen X-linked mutants have been isolated in Drosophila melanogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. Their characterization and preliminary assignment to functional groups is described. Four of these mutants are alleles of mei-41. Like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the X-chromosome in homozygous females. The remaining mutants have been tentatively assigned to six functional groups (two mutants to the mus(1)101 locus, two to mus(1)102, two to mus(1)103, and one each to mus(1)104, mus(1)105, and mus(1)106. Several of the complementation groups can be distinguished on the basis of nondisjunction and cross sensitivity to mutagens. Females homozygous for the mei-41, mus(1)101 and mus(1)102 mutants exhibit elevated levels of nondisjunction. Mutants belonging to complementation groups mei-41, mus(1)101, and mus(1)104 are sensitive to nitrogen mustard (HN2) in addition to their MMS sensitivity. Among these mutants there is currently a direct correlation between sensitivity to HN2, sensitivity to 2-acetylaminofluorene and a deficiency in post-replication repair. Only the mei-41 mutants are hypersensitive to uv radiation, although several of the mutants exhibit sensitivity to γ-rays. Semidominance is observed in female larvae of the mei-41, mus(1)104, and mus(1)103 mutants after exposure to high concentrations of MMS. The properties of the mutants generally conform to a pattern which has been established for related mutants in yeast

  8. Alcohol-tolerant mutants of cyanobacterium Synechococcus elongatus PCC 7942 obtained by single-cell mutant screening system.

    Science.gov (United States)

    Arai, Sayuri; Hayashihara, Kayoko; Kanamoto, Yuki; Shimizu, Kazunori; Hirokawa, Yasutaka; Hanai, Taizo; Murakami, Akio; Honda, Hiroyuki

    2017-08-01

    Enhancement of alcohol tolerance in microorganisms is an important strategy for improving bioalcohol productivity. Although cyanobacteria can be used as a promising biocatalyst to produce various alcohols directly from CO 2 , low productivity, and low tolerance against alcohols are the main issues to be resolved. Nevertheless, to date, a mutant with increasing alcohol tolerance has rarely been reported. In this study, we attempted to select isopropanol (IPA)-tolerant mutants of Synechococcus elongatus PCC 7942 using UV-C-induced random mutagenesis, followed by enrichment of the tolerant candidates in medium containing 10 g/L IPA and screening of the cells with a high growth rate in the single cell culture system in liquid medium containing 10 g/L IPA. We successfully acquired the most tolerant strain, SY1043, which maintains the ability to grow in medium containing 30 g/L IPA. The photosynthetic oxygen-evolving activities of SY1043 were almost same in cells after 72 h incubation under light with or without 10 g/L IPA, while the activity of the wild-type was remarkably decreased after the incubation with IPA. SY1043 also showed higher tolerance to ethanol, 1-butanol, isobutanol, and 1-pentanol than the wild type. These results suggest that SY1043 would be a promising candidate to improve alcohol production using cyanobacteria. Biotechnol. Bioeng. 2017;114: 1771-1778. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Biocontrol potential of salinity tolerant mutants of Trichoderma harzianum against Fusarium oxysporum Potencial de biocontrole de mutantes sal-tolerantes de Trichoderma harzianum contra Fusarium oxysporum

    Directory of Open Access Journals (Sweden)

    Hassan Abdel-Latif A. Mohamed

    2006-06-01

    Full Text Available Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable salt-tolerant mutants (Th50M6 and Th50M11. Under saline conditions, both mutants greatly surpassed their wild type strain in growth rate, sporulation and biological proficiency against Fusarium oxysporum, the causal agent of tomato wilt disease. Tolerant T. harzianum mutants detained a capability to grow and convinced sporulation in growth media containing up to 69 mM NaCl. In comparison with their parent strain, characterization of both mutants confirmed that they have reinforced contents of proline and hydroxyproline, relatively higher sodium content compared to potassium, calcium or magnesium contents, higher level of total phenols. Electrophoretic analysis of total soluble proteins in the salt tolerance mutant Th50M6 showed different bands accumulated in response to 69 mM NaCl. Data also showed that mutants produce certain active metabolites, such as chitinases, cellulases, beta-galactosidases, as well as, some antibiotics i.e., trichodermin, gliotoxin and gliovirin. Trichoderma mutants significantly reduced wilt disease incidence and improved yield and mineral contents of tomato plants under both saline and non-saline soil conditions, as well as, under infested and natural conditions. T. harzianum mutants were also more efficient in dropping the F. oxysporum growth in rhizosphere compared to the wild type strain. Population density of both mutants in rhizosphere far exceeded that of T. harzianum wild type strain.A exposição de uma cepa selvagem de Trichoderma harzianum à irradiação gama induziu dois mutantes tolerantes a sal (Th50M6 e Th50M11. Em condições salinas, os dois mutantes foram muito superiores à cepa selvagem em relação à velocidade de multiplicação, esporulação e eficiência contra Fusarium oxysporum, o agente causador da doença wilt do tomate. Os mutantes tolerantes foram capazes de multiplicação e esporulação em

  10. Masking Responses to Light in Period Mutant Mice

    Science.gov (United States)

    Pendergast, Julie S.; Yamazaki, Shin

    2013-01-01

    Masking is an acute effect of an external signal on an overt rhythm and is distinct from the process of entrainment. In the current study, we investigated the phase dependence and molecular mechanisms regulating masking effects of light pulses on spontaneous locomotor activity in mice. The circadian genes, Period1 (Per1) and Per2, are necessary components of the timekeeping machinery and entrainment by light appears to involve the induction of the expression of Per1 and Per2 mRNAs in the suprachiasmatic nuclei (SCN). We assessed the roles of the Per genes in regulating masking by assessing the effects of light pulses on nocturnal locomotor activity in C57BL/6J Per mutant mice. We found that Per1−/− and Per2−/− mice had robust negative masking responses to light. In addition, the locomotor activity of Per1−/−/Per2−/− mice appeared to be rhythmic in the light-dark (LD) cycle, and the phase of activity onset was advanced (but varied among individual mice) relative to lights off. This rhythm persisted for 1 to 2 days in constant darkness in some Per1−/−/Per2−/− mice. Furthermore, Per1−/−/Per2−/− mice exhibited robust negative masking responses to light. Negative masking was phase dependent in wild-type mice such that maximal suppression was induced by light pulses at zeitgeber time 14 (ZT14) and gradually weaker suppression occurred during light pulses at ZT16 and ZT18. By measuring the phase shifts induced by the masking protocol (light pulses were administered to mice maintained in the LD cycle), we found that the phase responsiveness of Per mutant mice was altered compared to wild-types. Together, our data suggest that negative masking responses to light are robust in Per mutant mice and that the Per1−/−/Per2−/− SCN may be a light-driven, weak/damping oscillator. PMID:21793695

  11. Ligand and proton exchange dynamics in recombinant human myoglobin mutants.

    Science.gov (United States)

    Lambright, D G; Balasubramanian, S; Boxer, S G

    1989-05-05

    Site-specific mutants of human myoglobin have been prepared in which lysine 45 is replaced by arginine (K45R) and aspartate 60 by glutamate (D60E), in order to examine the influence of these residues and their interaction on the dynamics of the protein. These proteins were studied by a variety of methods, including one and two-dimensional proton nuclear magnetic resonance spectroscopy, exchange kinetics for the distal and proximal histidine NH protons as a function of pH in the met cyano forms, flash photolysis of the CO forms, and ligand replacement kinetics. The electronic absorption and proton nuclear magnetic resonance spectra of the CO forms of these proteins are virtually identical, indicating that the structure of the heme pocket is unaltered by these mutations. There are, however, substantial changes in the dynamics of both CO binding and proton exchange for the mutant K45R, whereas the mutant D60E exhibits behavior indistinguishable from the reference human myoglobin. K45R has a faster CO bimolecular recombination rate and slower CO off-rate relative to the reference. The kinetics for CO binding are independent of pH (6.5 to 10) as well as ionic strength (0 to 1 M-NaCl). The exchange rate for the distal histidine NH is substantially lower for K45R than the reference, whereas the proximal histidine NH exchange rate is unaltered. The exchange behavior of the human proteins is similar to that reported for a comparison of the exchange rates for myoglobins having lysine at position 45 with sperm whale myoglobin, which has arginine at this position. This indicates that the differences in exchange rates reflects largely the Lys----Arg substitution. The lack of a simple correlation for the CO kinetics with this substitution means that these are sensitive to other factors as well. Specific kinetic models, whereby substitution of arginine for lysine at position 45 can affect ligand binding dynamics, are outlined. These experiments demonstrate that a relatively

  12. Application Of Database Program in selecting Sorghum (Sorghum bicolor L) Mutant Lines

    International Nuclear Information System (INIS)

    H, Soeranto

    2000-01-01

    Computer database software namely MSTAT and paradox have been exercised in the field of mutation breeding especially in the process of selecting plant mutant lines of sorghum. In MSTAT, selecting mutant lines can be done by activating the SELECTION function and then followed by entering mathematical formulas for the selection criterion. Another alternative is by defining the desired selection intensity to the analysis results of subprogram SORT. Including the selected plant mutant lines in BRSERIES program, it will make their progenies be easier to be traced in subsequent generations. In paradox, an application program for selecting mutant lines can be made by combining facilities of Table, form and report. Selecting mutant lines with defined selection criterion can easily be done through filtering data. As a relation database, paradox ensures that the application program for selecting mutant lines and progeny trachings, can be made easier, efficient and interactive

  13. Durable resistance to net blotch and agronomic performance in some barley mutants [Hordeum vulgare L.; Syria

    International Nuclear Information System (INIS)

    Arabi, M.I.E.

    2004-01-01

    Seeds from the net blotch (Pyrenophora teres) susceptible cultivar Thibaut were treated by gamma ray radiation and subsequently evaluated for reaction to the pathogen in the M2-M5 generations. Grain yield and agronomic characteristics of putative mutants were compared with Thibaut in two different locations. Genetic variation among some mutant lines/cv Thibaut was estimated using Amplified Fragment Length Polymorphism (AFLP) markers. Sixteen mutant lines and their mother cultivar Thibaut were analyzed with 14 EcoR1-Mse1 primer combinations. A total number of 504 AFLP bands were analyzed for each pair mutant/Thibaut. Narrow genetic variation among all genotypes was detected with an average of genetic similarity of 0.96. Cluster analysis with the entire AFLP data divided all genotypes into two major groups. The resistant mutant lines were grouped in one subcluster with 0.98 similarity index. Some resistant mutant lines to net blotch with good agronomic performances were produced [it

  14. Cloning, preparation and preliminary crystallographic studies of penicillin V acylase autoproteolytic processing mutants

    International Nuclear Information System (INIS)

    Chandra, P. Manish; Brannigan, James A.; Prabhune, Asmita; Pundle, Archana; Turkenburg, Johan P.; Dodson, G. Guy; Suresh, C. G.

    2004-01-01

    The production, crystallization and characterization of three inactive mutants of penicillin V acylase from B. sphaericus in their respective precursor and processed forms are reported. The space groups are different for the native enzyme and the mutants. The crystallization of three catalytically inactive mutants of penicillin V acylase (PVA) from Bacillus sphaericus in precursor and processed forms is reported. The mutant proteins crystallize in different primitive monoclinic space groups that are distinct from the crystal forms for the native enzyme. Directed mutants and clone constructs were designed to study the post-translational autoproteolytic processing of PVA. The catalytically inactive mutants will provide three-dimensional structures of precursor PVA forms, plus open a route to the study of enzyme–substrate complexes for this industrially important enzyme

  15. RAPD analysis of mutants obtained by ion beam irradiation to hinoki cypress shoot primordia

    International Nuclear Information System (INIS)

    Ishii, K.; Yamada, Y.; Hase, Y.; Shikazono, N.; Tanaka, A.

    2003-01-01

    Mutants were induced by irradiation of the shoot primordia of Hinoki cypress with 50 MeV 4 He 2+ heavy ion beam. Fresh shoot primordia on the CD medium in the plastic Petri dish (35 x 10 mm) were irradiated. Xanta mutants were induced from 38 to 266 Gy irradiation. Waxy mutants were induced from 76 to 266 Gy irradiation. Xanta, waxy and control type of regenerated Hinoki cypress in vitro were checked for their DNA level difference using RAPD analysis. Among 81 primers used, 23 primers produced the 68 bands. Among them stable 44 bands produced by 15 primers were compared between mutants and control plant. So far, there is no variation among the RAPD analysis band patterns of those mutants. Bigger test size may detect the gene variation specific for mutants

  16. Root and Nodulation Phenotypes of the Ethylene-Insensitive Sickle Mutant of Medicago truncatula

    Directory of Open Access Journals (Sweden)

    JOKO PRAYITNO

    2010-09-01

    Full Text Available The sickle (skl mutant of the model legume Medicago truncatula is an ethylene-sensitive mutant that have a ten-fold increase in nodule numbers. The nodulation and root phenotypes of the skl mutant were investigated and further characterised. The skl mutant had longer roots than the wild type, but when inoculated with Sinorhizobium, its root length was reduced to the level of wild type. Furthermore, lateral root numbers in uninoculated skl were similar to those in uninoculated wild type. However, when the root tips were decapitated, fewer lateral roots formed in skl than in wild type. Nodule numbers of the skl mutant were significantly reduced by low nitrate concentration (2.5 mM. These results suggest that skl mutant has alterations in both root and nodule development.

  17. Genetical, cytological and physiological studies on the induced mutants with special regard to effective methods for obtaining useful mutants in perennial woody plant

    International Nuclear Information System (INIS)

    Kukimura, H.; Ikeda, F.; Fujita, H.; Maeta, T.; Nakajima, K.; Katagiri, K.; Nakahira, K.; Somegou, M.

    1976-01-01

    The plants studied included apple trees, cryptomeria (japanese cedar) and mulberry. In apple, dwarf and compact types of mutants from cv. Fuji were found to be graft incompatible on Maruba-kaido(Malus prunifolia) rootstock. In Sunki mandarin(Citrus sunki), the number of nucellar embryo per seed was affected by gamma-irradiation, and morphological mutants from nucellar seedlings were obtained at high rate by irradiation at floral bud stage with 2kR exposure. In Cryptomeria, re-irradiated waxless mutants by gamma-rays showed very high rate of somatic mutation when compared to other morphological mutants. Pollen sterility and pollen shaped PMC were found in the most of gamma-induced-mutants. Mutants forming pollen shaped PMC had a genetical tendency of continuous male flower bud formation for a longer term. With mulberry, time of sprouting of induced mutants differed from the originals. Ability of root initiation of semi-softwood cuttings in morphological mutants were tested. Cytochimera induction were found at considerably high rate when actively growing diploid plants were irradiated by gamma-rays. Eight kinds of cytochimeras were induced. Frequency of 2-4-4 was extremely high(approx. 50%), then 4-2-2 and 2-4-2 chimeras followed. Seven kinds were induced by semi-acute irradiation(200R/h), while 4 kinds by acute irradiation(5kR/h). By breeding test it was cleared that the elongate and entire leaf was sexually transmissible, whereas the 'dwarf' was not obvious and the 'marginally curledleaf' was not transmissible. Pyronin-methylgreen staining method proved to be useful in some morphological mutants to distinguish the histo-genetical differences which exist in the shoot apex.

  18. Yield and its components and some agronomic characters of four mungbean mutants induces by gamma ray

    International Nuclear Information System (INIS)

    Al-Mosawi, A. R. A.; Ibrahim, A. F.; Azzo, F. Z.; Khadim, A. A.; Ibrahim, W. H.; Abdul-Al-majed, A.

    2012-12-01

    A field experiment was carried out at the Tuwaitha research station / Iraqi Atomic Energy Commission (past) Ministry of science and Technology (now) in Agricultural seasons 2000 - 2001 to evaluate four mungbean mutants induced by gamma ray compared with local variety and Australian pedigree. The results showed that mutants AMU-45 was superiority on anther mutants and the local in date of flowering (41.50 days), maturity (71.25 days), yield (1609.88 kg/ha) and its components. (Author)

  19. Whole-Genome Sequencing of Sordaria macrospora Mutants Identifies Developmental Genes.

    Science.gov (United States)

    Nowrousian, Minou; Teichert, Ines; Masloff, Sandra; Kück, Ulrich

    2012-02-01

    The study of mutants to elucidate gene functions has a long and successful history; however, to discover causative mutations in mutants that were generated by random mutagenesis often takes years of laboratory work and requires previously generated genetic and/or physical markers, or resources like DNA libraries for complementation. Here, we present an alternative method to identify defective genes in developmental mutants of the filamentous fungus Sordaria macrospora through Illumina/Solexa whole-genome sequencing. We sequenced pooled DNA from progeny of crosses of three mutants and the wild type and were able to pinpoint the causative mutations in the mutant strains through bioinformatics analysis. One mutant is a spore color mutant, and the mutated gene encodes a melanin biosynthesis enzyme. The causative mutation is a G to A change in the first base of an intron, leading to a splice defect. The second mutant carries an allelic mutation in the pro41 gene encoding a protein essential for sexual development. In the mutant, we detected a complex pattern of deletion/rearrangements at the pro41 locus. In the third mutant, a point mutation in the stop codon of a transcription factor-encoding gene leads to the production of immature fruiting bodies. For all mutants, transformation with a wild type-copy of the affected gene restored the wild-type phenotype. Our data demonstrate that whole-genome sequencing of mutant strains is a rapid method to identify developmental genes in an organism that can be genetically crossed and where a reference genome sequence is available, even without prior mapping information.

  20. Isolation of glutathione-deficient mutants of the yeast Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Kistler, M.; Eckardt, F.; Summer, K.-H.

    1986-01-01

    Glutathione-deficient (gsh - ) mutants of the yeast Saccharomyces cerevisiae were isolated after UV treatment using MNNG as selective agent. For genetic and biochemical characterization 5 mutant strains were chosen which exhibited considerably decreased residual GSH contents varying from 2 to 6% of the wild-type levels. All 5 isolates showed a 2:2 segregation of the gsh - :GSH + phenotypes alluding to a monogenic recessive mutation. Complementation analysis indicates that all gsh - mutants belong to one complementation group. (Auth.)

  1. Benomyl-resistant mutant strain of Trichoderma sp. with increased mycoparasitic activity.

    Science.gov (United States)

    Olejníková, P; Ondrusová, Z; Krystofová, S; Hudecová, D

    2010-01-01

    Application of UV radiation to the strain Trichoderma sp. T-bt (isolated from lignite) resulted in the T-brm mutant which was resistant to the systemic fungicide benomyl. The tub2 gene sequence in the T-brm mutant differed from the parent as well as the collection strain (replacing tyrosine with histidine in the TUB2 protein). Under in vitro conditions this mutant exhibited a higher mycoparasitic activity toward phytopathogenic fungi.

  2. Studies of peroxidase isozyme profile in mungbean mutants

    International Nuclear Information System (INIS)

    Auti, S.G.; Apparao, B.J.

    2007-01-01

    Peroxidase is an important oxygen-scavenging enzyme. The activity of peroxidase is often correlated with growth, development and hormonal activity. Traditional methods of cultivar identification usually involve observation and recording of morphological characters or description such as yield, height, weight, earliness etc. which vary with environmental conditions and often misleading. So molecular markers like protein and isozymes profiles, RFLP, RAPDs markers etc. are widely employed in varietal identification of cultivars. It plays important role in respiration and is an indicator of oxidative status of plants. Electrophoretic techniques have been used to group species and identify cultivars. Such identification has various advantages including the unique pattern of protein or isozymes bands for each pure cultivar under any set of environmental conditions. Peroxidase isozyme serves as very good marker for any mutational studies. In the present investigation, peroxidase isozyme profiles of various mutants of mungbean was studied employing the technique of electrophoresis

  3. Induction of Male sterile mutants in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Nobuhiko [Hokkaido National Agricultural Experiment Station, Sapporo (Japan)

    1982-03-01

    The cultivars of vegetable crops in Japan are almost all F/sub 1/ hybrid lines. These hybrid cultivars are superior in yield, quality and uniformity by heterosis, and play an important role in the protection of breeder's rights. Utilization of male sterile mutants has such advantages as the reduction of cost for F/sub 1/ production by saving labor, production of better seeds, that is, pollination without emasculation and avoidance of contamination caused by self pollination. Male sterility must be used for some species in which seed production is difficult because of tiny flowers and meager seed production by artificial crossing such as carrot and onion, and those in which pollination by bag or emasculation is expensive such as tomato, and sweet pepper. However, for vegetable crop breeeding, the induction and use of genetic male sterility are more difficult than for other crops, considering the economy and efficiency of research because the type of cultivars needed changes rapidly.

  4. An apoptotic cell cycle mutant in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Villadsen, Ingrid

    1996-01-01

    The simple eukaryote Saccharomyces cerevisiae has proved to be a useful organism for elucidating the mechanisms that govern cell cycle progression in eukaryotic cells. The excellent in vivo system permits a cell cycle study using temperature sensitive mutants. In addition, it is possible to study...... many genes and gene products from higher eukaryotes in Saccharomyces cerevisiae because many genes and biological processes are homologous or similar in lower and in higher eukaryotes. The highly developed methods of genetics and molecular biology greatly facilitates studies of higher eukaryotic...... processes.Programmmed cell death with apoptosis plays a major role in development and homeostatis in most, if not all, animal cells. Apoptosis is a morphologically distinct form of death, that requires the activation of a highly regulated suicide program. Saccharomyces cerevisiae provides a new system...

  5. Carbon and energy metabolism of atp mutants of Escherichia coli

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Michelsen, Ole

    1992-01-01

    strain is not able to utilize the resulting proton motive force for ATP synthesis. Indeed, the ratio of ATP concentration to ADP concentration was decreased from 19 in the wild type to 7 in the atp mutant, and the membrane potential of the atp deletion strain was increased by 20%, confirming......The membrane-bound H+-ATPase plays a key role in free-energy transduction of biological systems. We report how the carbon and energy metabolism of Escherichia coli changes in response to deletion of the atp operon that encodes this enzyme. Compared with the isogenic wild-type strain, the growth...... rate and growth yield were decreased less than expected for a shift from oxidative phosphorylation to glycolysis alone as a source of ATP. Moreover, the respiration rate of a atp deletion strain was increased by 40% compared with the wild-type strain. This result is surprising, since the atp deletion...

  6. Customer Acceptance Survey On Chrysanthemum Mutant Developed By Nuclear Malaysia

    International Nuclear Information System (INIS)

    Shakinah Salleh; Zaiton Ahmad; Affrida Hassan; Shuhaimi Shamsudin; Nurul Hidayah Mahmud; Salim Othman; Mohamed Najli Mohamed Yasin

    2014-01-01

    Chrysanthemum morifolium is an important temperate cut flower for Malaysian floriculture industry and the lack of new local-owned varieties has led to this mutation breeding research. The project was started in 2008 under bilateral cooperation between Nuclear Malaysia and JAEA (Japan Atomic Energy Agency). Through this project, 8 new varieties of chrysanthemum were successfully developed, in which 4 varieties were from red cultivar and another 4 from pink cultivar. A preliminary survey on public perception and acceptance of these mutants was conducted on 7 January 2014 at Agrotechnology and Biosciences Division, Malaysian Nuclear Agency. The main objective of this survey was to gather information from the public on overall appearance of these new varieties and their potential for commercialization. Approximately 60 participants were involved in this survey, which include staff of Nuclear Malaysia, university students, plant growers/collectors and hobbyists. (author)

  7. Jeast (Saccharomyces cerevisial) mutants with enhanced induced mutagenesis

    International Nuclear Information System (INIS)

    Ivanov, E.L.; Koval'tsova, S.V.; Korolev, V.G.

    1987-01-01

    The influence of him1-1, him2-1, him3-1 and himX mutations on induction frequency and specificity of UV-induced adenine-dependent mutations in the yeast Saccharomyces cerevisiae has been. Him mutations do not render haploid cells more sensitive to the lethal action of UV-light; however, in him strains adeine-dependent mutations (ade, ade2) were induced more frequently (1.5-2-fold), as compared to the HIM strain. An analysis of the molecular nature of ade2 mutants revealed than him1-1, him2-1, and himX mutations increase specifically the yield of transitions (AT-GC and GC→AT), whereas in the him3-1, strain the yield of transversions was enhanced as well. We suggest him mutations analysed to affect specific repair pathway for mismatch correction

  8. Creating Sunflower Mutant Lines (Helianthus Annuus L.) Using Induced Mutagenesis

    International Nuclear Information System (INIS)

    Encheva, J.

    2009-01-01

    Immature sunflower zygotic embryos of sunflower fertility restorer line 374 R were treated with ultrasound and gamma radiation before plating embryos to culture medium. All plants were isolated and self-pollinated for several generations. New sunflower forms with inherited morphological and biochemical changes were obtained. The genetic changes occurring during the mutation procedure included fourteen morphological and biochemical characters. In comparison to the check line 374 R, decreasing of the mean value of the indexes was registered for 33 % of the total number of characters and vise verse, significant increasing was observed for 60 %. Mutation for resistance to the local population of Orobanche cumana race A-E was obtained from the susceptible Bulgarian control line 374 R. Two investigated mutant lines possessed 100 % resistance to Orobanche and stable inheritance in the next generations. Our results showed that induced mutagenesis in sunflower can be successfully used to develop new lines useful for heterosis breeding

  9. Catalytic properties of ADAM12 and its domain deletion mutants

    DEFF Research Database (Denmark)

    Jacobsen, Jonas; Visse, Robert; Sørensen, Hans Peter

    2008-01-01

    of pro, catalytic, disintegrin, cysteine-rich, and EGF domains. Here we present a novel activity of recombinant ADAM12-S and its domain deletion mutants on S-carboxymethylated transferrin (Cm-Tf). Cleavage of Cm-Tf occurred at multiple sites, and N-terminal sequencing showed that the enzyme exhibits...... restricted specificity but a consensus sequence could not be defined as its subsite requirements are promiscuous. Kinetic analysis revealed that the noncatalytic C-terminal domains are important regulators of Cm-Tf activity and that ADAM12-PC consisting of the pro domain and catalytic domain is the most...... active on this substrate. It was also observed that NaCl inhibits ADAM12. Among the tissue inhibitors of metalloproteinases (TIMP) examined, the N-terminal domain of TIMP-3 (N-TIMP-3) inhibits ADAM12-S and ADAM12-PC with low nanomolar Ki(app) values while TIMP-2 inhibits them with a slightly lower...

  10. NH exchange in point mutants of human ubiquitin.

    Science.gov (United States)

    Jahr, Nicole; Fiedler, Erik; Günther, Robert; Hofmann, Hans-Jörg; Berger, Stefan

    2011-08-01

    Several point mutants of human ubiquitin (Ub(T9V), Ub(F45W), Ub(F45G), and Ub(A46S)) were prepared by recombinant techniques. The NH exchange rate constants were measured by the NMR diffusion and the MEXICO methods and compared with those in the wild type to examine the influence of structural changes and to improve the understanding of this important reaction in studies of protein folding and denaturation. The observed changes follow qualitatively the polarity and steric alterations caused by the introduced amino acids. Attempts to reproduce quantitatively the observed changes by modeling studies and molecular dynamics simulations were not satisfactory. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Induction of Male sterile mutants in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Nobuhiko (Hokkaido National Agricultural Experiment Station, Sapporo (Japan))

    1982-03-01

    The cultivars of vegetable crops in Japan are almost all F/sub 1/ hybrid lines. These hybrid cultivars are superior in yield, quality and uniformity by heterosis, and play an important role in the protection of breeder's rights. Utilization of male sterile mutants has such advantages as the reduction of cost for F/sub 1/ production by saving labor, production of better seeds, that is, pollination without emasculation and avoidance of contamination caused by self pollination. Male sterility must be used for some species in which seed production is difficult because of tiny flowers and meager seed production by artificial crossing such as carrot and onion, and those in which pollination by bag or emasculation is expensive such as tomato, and sweet pepper. However, for vegetable crop breeeding, the induction and use of genetic male sterility are more difficult than for other crops, considering the economy and efficiency of research because the type of cultivars needed changes rapidly.

  12. Induction of Male sterile mutants in vegetable crops

    International Nuclear Information System (INIS)

    Nagata, Nobuhiko

    1982-01-01

    The cultivars of vegetable crops in Japan are almost all F 1 hybrid lines. These hybrid cultivars are superior in yield, quality and uniformity by heterosis, and play an important role in the protection of breeder's rights. Utilization of male sterile mutants has such advantages as the reduction of cost for F 1 production by saving labor, production of better seeds, that is, pollination without emasculation and avoidance of contamination caused by self pollination. Male sterility must be used for some species in which seed production is difficult because of tiny flowers and meager seed production by artificial crossing such as carrot and onion, and those in which pollination by bag or emasculation is expensive such as tomato, and sweet pepper. However, for vegetable crop breeeding, the induction and use of genic male sterility are more difficult than for other crops, considering the economy and efficiency of research because the type of cultivars needed changes rapidly. (Kaihara, S.)

  13. Adaptive response in Drosophila melanogaster heat shock proteins mutant strains

    International Nuclear Information System (INIS)

    Shaposhnikov, M.V.; Moskalev, A.A.; Turysheva, E.V.

    2007-01-01

    Complete text of publication follows. The members of the heat shock proteins (Hsp) family function as molecular chaperones and assist intracellular folding of newly synthesized proteins. Also it is possible that molecular chaperones are induced during adaptive response to oxidative stress and radiation. The aim of our research was to exam the role of heat shock proteins in adaptive response to oxidative stress after low dose rate gamma-irradiation in Drosophila melanogaster. Drosophilamelanogaster strains were kindly provided by Bloomington Drosophila Stock Center (University of state of Indiana, Bloomington, USA). We used wild type strain (CS), heat shock protein mutant strains (Hsp22, Hsp70, Hsp83), and heat shock factor mutant strain (Hsf). Strains were chronically exposured to adaptive dose of gamma-irradiation in dose rate of 0.17 cGy/h during all stages of life history (from the embrional stage to the stage of matured imago). The rate of absorbed dose was 60 cGy. For oxidative-stress challenge twodays old flies were starved in empty vials for 6 h and then transferred to vials containing only filter paper soaked with 20 mM paraquat in 5% sucrose solution. Survival data were collected after 26 h of treatment. Dead flies were counted daily. The obtained data were subjected to survival analysis by Kaplan and Meier method and presented as survival curves. Statistical analysis was held by non-parametric methods. To test the significance of the difference between the two age distributions Kolmogorov-Smirnov test was applied. Gehan-Braslow- Wilcoxon and Cox-Mantel tests were used for estimation of median life span differences. In addition the minimal and maximal life span, time of 90% death, and mortality rate doubling time (MRDT) were estimated. The obtained results will be discussed in presentation.

  14. Promising mutant varieties of groundnut evolved through gamma irradiation

    International Nuclear Information System (INIS)

    Sinha, P.K.; Rahman, H.

    1980-01-01

    The Chotanagpur plateau region of Bihar is the main potential area for groundnut cultivation in the State. Var. AK 12-24 - an early, bunch type - has been the predominant variety under cultivation. Because of special nature of soil and rainfall pattern of this area, it is desirable to evolve a variety with early to mid-early maturity and bunch habit, but with improved yield potential over the ruling var. AK 12-24. Two bold podded mutants BP 1 and BP 2 were obtained throuo.h gamma irradiation of var 41-C which is a late maturing variety (135-140 days), spreading in habit and with medium kernel and pod size, whereas the mutant varieties have early (110-115 days for BP 1) to mid-early (115-120 days for BP 2) maturity, bunch habit and bold kernel and pods (HKW 55-60 gm for BP 1 and 60-66 gms for BP 2). Both have 20-25% higher yield potential over AK 12-24. The results of 3 years' yield evaluation trials at Kanke and one year minikit trials at different locations in Bihar show that BP 1 and BP 2 have significantly outyielded the check AK 12-24 and were at par with each other. Both varieties -because of their bold seededness - come under HPS type and have good export market. These varieties have now been released by the Rajendra Agricultural University as Sonya Bold 1 and Sonya Bold 2 for cultivation in Bihar. (author)

  15. Creation and evaluation of best cotton mutant lines

    International Nuclear Information System (INIS)

    Rastegari, S. J.; Hosseini, Z.

    2001-01-01

    During (1997-1999) a study was carried out to recognize the best mutant lines, which were already obtained from a mutation breeding project. A Triple Rectangular Latis Design (8 7) in form of randomized complete blocks (RCB) with fifty- six treatments and three replications, were used in Estahban, Kordkouy and Varamin, under different ecological conditions, rainfall (Kordkouy) desert (Varamin) hot and dry (Estahban). During growing season some important morphological characteristics were recorded. Some lines had specific characters, for example: line 3191 (Chirpan 150 gray) had a low leaf number per plant, line 3169 (Bakhtegan 200 gray) plants were clustered. The results of the data in Varamin station showed that Bakhtegan irradiated with 150 gray line 3485 and Tashkand with 300 gray line 3451 compared to check (Varamin with 4373 kg/ha) had highest yield with 4942 kg/ha, and 4871 kg/ha respectively. In view of boll weight line 3405 of Sahel irradiated with 200 gray had highest boll weight (6.5 g/boll). In Kordkouy station the best mutant line was Chirpan irradiated with 250 gray, line 3208, with 20% yield increase compared to Sahel and 30% yield increase compared to original Chirpan. In respect to irradiation effect on lint percentage and fiber quality, the results showed; there was a positive effect on lint percentage of all varieties, especially in Tashkant, Bakhtegan and Chirpan which are inherently weak in lint percentage. As a whole gamma radiation did not have any negative effect on fiber quality. Even in Estahban 1.6 to 2.4 mm fiber increase were observed in some Chirpan irradiated material (C150-3516) and (C200-3523)

  16. Genetic analysis and molecular detection of the corn endosperm mutants induced by space flight

    International Nuclear Information System (INIS)

    Zhang Caibo; Zhou Yuanyuan; Wang Hanyu; Wang Hongwei; Wang Shengqing; Rong Tingzhao; Cao Moju

    2013-01-01

    In this study, two maize inbred lines 08-641 and 18-599 were carried into cosmic space by recoverable satellite 'Shijian 8', grain shrunken transparently and opaquely mutants were selected as experimental materials and their soluble sugar content in kernel were measured by annthrone colorimetry. The content of soluble sugar in mutant st1 kernels began to rise in 10 days after pollination, to reach the peak in 25 days and significantly higher than the contrast 08-641, while in mutant sol kernels it began to rise in 10 days after pollination, to reach the peak in 20 days and significantly higher than the contrast 18-599. The results of genetic analysis and allelism test showed that the trait in both mutants was all controlled by a single recessive gene, the mutant st1 was allelic to the su1 and the mutant sol was allelic to the sh2. DNA sequence alignment found 2 single-base mutations in 2 and 13 exon of su1 gene in the mutant st1 and 3 single-base mutations in 2, 5 and 16 exon of sh2 gene in mutant so1 leading to the change in amino acid sequences. So it is inferred that starch biosynthesis in the mutants may be blocked by these mutations, which lead to the increase of soluble sugar content in kernel. (authors)

  17. Influence of ultraviolet light on arising of induced mutants in Cercospora beticola sacc

    Energy Technology Data Exchange (ETDEWEB)

    Brillova, D [Institute of Experimental Phytopathology and Entomology of the Slovak Academy of Sciences, Ivanka pri Dunaji (Czechoslovakia)

    1976-01-01

    Ultraviolet radiation of wavelengths of 254 and 350 nm respectively, applied for 30 to 480 seconds to the conidia of Cercospora beticola, induced a large number of mutants. According to their appearance, the occurring mutants can be considered as visible with effect on morphology and colour. A considerable part of the mutants lost its ability to form reproductive organs in in vitro conditions, as well as on the host plant; they became avirulent. Moreover, mutants occurred with decreased virulence, with a weak forming of conidia and prolonged incubation period. In few cases, also reverse mutations were induced characterized by increased virulence.

  18. Growth and sporulation of a pyrimidine spore color mutant of Sordaria fimicola.

    Science.gov (United States)

    el-Ani, A S

    1967-04-07

    A nonautonomous spore color mutant of Sordaria fimicola is a pyrimidine auxotroph that produces hyaline nonviable ascospores. Uracil, uridine, and cytidine are more effective growth factors than cytosine and thymine and, in high concentrations, render the mutant self-fertile by inducing the ascospores to resume development and maturation. Crosses with the unlinked arginine non-autonomus spore color mutant st-59 yielded the double mutant st-59 pyr that requires both arginine and a pyrimidine for growth, which indicates a lack of suppression of the pyrimidine requirement by the arginine locus.

  19. UV and gamma-ray sensitivity of meiosis-deficient mutants in Podospora anserina

    International Nuclear Information System (INIS)

    Simonet, J.M.

    1976-01-01

    Two mutants, mei1 and mei2, were isolated by screening for deficiencies occurring in the meiotic process. The sensitivity of mei1 and mei2 mutant strains to UV irradiation showed a significant increase as compared with that of the wild-type stock, hwhereas the sensitivity to γ-rays remained unchanged. The double-mutant strains were no more sensitive than each single mutant. The data indicate that both mei1 and mei2 loci are probably involved in the same pathway of excision-repair of UV-induced lesions

  20. Cytoembryologic study of gamma-ray induced sterile Pisum sativum L. mutants

    International Nuclear Information System (INIS)

    Molkhova, E.; Vasileva, M.

    1977-01-01

    Three new pea mutant forms are described - 1878, Crampled petal Waxless type, and Lathyrus type - which were induced by different gamma-ray ( 60 Co) doses and rates. The flowers of the 1878 and Crampled petal Waxless type mutants were very much deformed, while those of the Lathyrus type had smaller flowers with normal morphology. The three mutant forms were entirely sterile and were propagated by segregation in the progeny of heterozygous sister plants. PMC meiosis and the development of the male gametophyte of the Lathyrus type mutant had a normal course, while in the mutant forms Crampled petal Waxless type and 1878 slight disturbances were observed, but the pollen of all three mutants was not functional. The development of the female gametophyte of the three mutants stops at an early phase and only in the Lathyrus type mutant in single cases embryosacks were formed with differentiated sex apparatus and early stages of embryo and endosperm development were scored, but they also soon degenerate. It is pointed out that sterility of the three pea mutant forms studied depends on factors, which stop at different stages the normal development of the generative organs, of the female gametophyte and of embryogenesis. (author)

  1. Mutant frequency of radiotherapy technicians appears to be associated with recent dose of ionizing radiation

    International Nuclear Information System (INIS)

    Messing, K.; Ferraris, J.; Bradley, W.E.; Swartz, J.; Seifert, A.M.

    1989-01-01

    The frequency of hypoxanthine phosphoribosyl transferase (HPRT) mutants among peripheral T-lymphocytes of radiotherapy technicians primarily exposed to 60Co was measured by the T-cell cloning method. Mutant frequencies of these technicians in 1984 and 1986 were significantly higher than those of physiotherapy technicians who worked in a neighboring service, and correlated significantly with thermoluminescence dosimeter readings recorded during the 6 mo preceding mutant frequency determination. Correlations decreased when related to dose recorded over longer time intervals. HPRT mutant frequency determination in peripheral lymphocytes is a good measure of recently received biologically effective radiation dose in an occupationally exposed population

  2. Uvm mutants of Escherichia coli K 12 deficient in UV mutagenesis. Pt. 1

    International Nuclear Information System (INIS)

    Steinborn, G.

    1978-01-01

    Selection for defective reversion induction, after UV treatment of E. coli K 12, yielded uvm mutants. These mutants exhibited highly reduced or no UV mutability for all loci tested although they were moderately and normally mutable by X-rays and EMS, respectively. Uvm mutations confer only a slight sensitivity to killing by UV and X-rays and no clear sensitivity to the lethal effect of HN2, EMS or MMS. Growth and viability of untreated uvm cells were normal. The properties of uvm mutants are discussed in relation to those of other relevant mutant types and to some actual problems of induced mutagenesis. (orig.) 891 AJ [de

  3. Repair-defective mutants of Alteromonas espejiana, the host for bacteriophage PM2

    International Nuclear Information System (INIS)

    Zerler, B.R.; Wallace, S.S.

    1984-01-01

    The in vivo repair processes of Alteromonas espejiana, the host for bacteriophage PM2, were characterized, and UV- and methyl methanesulfonate (MMS)-sensitive mutants were isolated. Wild-type A. espejiana cells were capable of photoreactivation, excision, recombination, and inducible repair. There was no detecttable pyrimidine dimer-DNA N-glycosylase activity, and pyrimidine dimer removal appeared to occur by a pathway analogous to the Escherichia coli Uvr pathway. The UV- and MMS-sensitive mutants of A. espejiana included three groups, each containing at least one mutation involved with excision, recombination, or inducible repair. One group that was UV sensitive but not sensitive to MMS or X rays showed a decreased ability to excise pyrimidine dimers. Mutants in this group were also sensitive to psoralen plus near-UV light and were phenotypically analogous to the E. coli uvr mutants. A second group was UV and MMS sensitive but not sensitive to X rays and appeared to contain mutations in a gene(s) involved in recombination repair. These recombination-deficient mutants differed from the E. coli rec mutants, which are MMS and X-ray sensitive. The third group of A. espejiana mutants was sensitive to UV, MMS, and X rays. These mutants were recombination deficient, lacked inducible repair, and were phenotypically similar to E. coli recA mutants

  4. Mutant frequency of radiotherapy technicians appears to be associated with recent dose of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Messing, K.; Ferraris, J.; Bradley, W.E.; Swartz, J.; Seifert, A.M. (Universite du Quebec a Montreal (Canada))

    1989-10-01

    The frequency of hypoxanthine phosphoribosyl transferase (HPRT) mutants among peripheral T-lymphocytes of radiotherapy technicians primarily exposed to 60Co was measured by the T-cell cloning method. Mutant frequencies of these technicians in 1984 and 1986 were significantly higher than those of physiotherapy technicians who worked in a neighboring service, and correlated significantly with thermoluminescence dosimeter readings recorded during the 6 mo preceding mutant frequency determination. Correlations decreased when related to dose recorded over longer time intervals. HPRT mutant frequency determination in peripheral lymphocytes is a good measure of recently received biologically effective radiation dose in an occupationally exposed population.

  5. Collection of rice mutants and application studies of their agronomic characters

    International Nuclear Information System (INIS)

    Sun Shuxiang; Jin Wei; Luo Qian; Sheng Ping; Huang Rongmin

    1993-01-01

    More than 1600 accessions of rice mutant germplasm have been collected since 1980, and 1142 accessions of mutants have been identified according to their agronomy and pattern characters. A part of mutants were compared with their original cultivars in eight main agronomic characters. The results showed that the agronomic characters of mutants induced by ionizing radiations changed to both positive and negative directions compared with their original cultivars. Only 6.3% mutants varied in single agronomic character, and 91.1% mutants varied in two to six agronomic characters. Tenetic analysis and Cellular observations were carried out for two kinds of early mutants. It showed that early mutants 'Yuan Feng Zao' are controlled by two independent and incomplete dominant genes. For the dwarf, the reduction of the number of longitudinal cell layers causes the stem shorter and the increase of the number of horizontal cell layers causes the stem wall thicker. More than 100 preserved accessions of mutants were supplied to breeding units as parents or for genetic studies. Sixteen cultivars (lines) were bred from the parents which played an important role in raising the output of rice production

  6. Plant cultivars derived from mutation induction or the use of induced mutants in cross breeding

    International Nuclear Information System (INIS)

    Micke, A.; Maluszynski, M.; Donini, B.

    1985-01-01

    Since 1969 we have collected information on cultivated varieties of plants, developed by using induced mutations. Whenever we learn about a cultivar presumably derived from an induced mutant or from use of mutants in crosses. we mail a questionnaire to the breeder. The information gathered in this way is stored in our file on ''Mutant Varieties''. Excerpts are published regularly in the form of a list in the FAO/IAEA Mutation Breeding Newsletter. Our mutant variety list has repeatedly provided a basis for analyses on the value and prospects of mutation breeding

  7. Mutants of Streptomyces coeruleorubidus impaired in the biosynthesis of daunomycinone glycosides and related metabolites

    International Nuclear Information System (INIS)

    Blumauerova, M.; Stajner, K.; Pokorny, V.; Hostalek, Z.; Vanek, Z.

    1978-01-01

    Mutants of Streptomyces coeruleorubidus, blocked in the biosynthesis of anthracycline antibiotics of the daunomycine complex, were isolated from the production strains after treatment with UV light, γ-radiation, nitrous acid, and after natural selection; according to their different biosynthetic activity the mutants were divided into five phenotypic groups. Mutants of two of these groups produced compounds that had not yet been described in Streptomyces coeruleorubidus (aklavinone, 7-deoxyaklavinone, zeta-rhodomycinone and glycosides of epsilon-rhodomycinone). The mutants differed from the parent strains and also mutually in morphological characteristics but no direct correlation between these changes and the biosynthetic activity could be observed in most cases. (author)

  8. Plant cultivars derived from mutation induction or the use of induced mutants in cross breeding

    Energy Technology Data Exchange (ETDEWEB)

    Micke, A; Maluszynski, M; Donini, B [Joint FAO/IAEA Division, Plant Breeding and Genetics Section, Vienna (Austria)

    1985-05-01

    Since 1969 we have collected information on cultivated varieties of plants, developed by using induced mutations. Whenever we learn about a cultivar presumably derived from an induced mutant or from use of mutants in crosses. we mail a questionnaire to the breeder. The information gathered in this way is stored in our file on ''Mutant Varieties''. Excerpts are published regularly in the form of a list in the FAO/IAEA Mutation Breeding Newsletter. Our mutant variety list has repeatedly provided a basis for analyses on the value and prospects of mutation breeding.

  9. The pathogenicity of thymidine kinase-deficient mutants of herpes simplex virus in mice.

    Science.gov (United States)

    Field, H J; Wildy, P

    1978-10-01

    The pathogenicity for mice of two mutants of herpes simplex virus (type 1 and type 2), which fail to induce thymidine kinase, were compared with their respective parent strains. The mutants were much less virulent than the parents following either intracerebral or peripheral inoculation. The replication of the virus at the site of inoculation and its progression into the nervous system were studied. Following a very large inoculum in the ear, the type 1 mutant was found to establish a latent infection in the cervical dorsal root ganglia. Mice inoculated intracerebrally with small doses of the mutant viruses were solidly immune to challenge with lethal doses of the parent strain.

  10. Construction of insertion and deletion mxa mutants of Methylobacterium extorquens AM1 by electroporation.

    Science.gov (United States)

    Toyama, H; Anthony, C; Lidstrom, M E

    1998-09-01

    Methylobacterium extorquens AM1 is a pink-pigmented facultative methylotroph which is widely used for analyzing pathways of C1 metabolism with biochemical and molecular biological techniques. To facilitate this approach, we have applied a new method to construct insertion or disruption mutants with drug resistance genes by electroporation. By using this method, mutants were obtained in four genes present in the mxa methylotrophy gene cluster for which the functions were unknown, mxaR, mxaS, mxaC and mxaD. These mutants were unable to grow on methanol except the mutant of mxaD, which showed reduced growth on methanol.

  11. Evaluation of some garlic (Allium Sativum L.) mutants resistant to white rot disease by RAPD analysis

    International Nuclear Information System (INIS)

    Nabulsi, I.; Al-Safadi, B.; Mir ali, N.; Arabi, M.I.E.

    2002-01-01

    Random amplified polymorphic DNA (RAPD) analysis was used to evaluate genetic diversity among eight garlic mutants resistant to white rot disease (Sclerotium cepivorum) and two controls. Twelve of 13 synthetic random primers were found to identify polymorphism in amplification products. Mutants characterised with moderate resistance to white rot were closely related to the control using cluster and correlation analyses. On the other hand, highly resistant mutants were quite distant from the control with low correlation coefficients. The banding patterns produced by primer OPB-15 (GGAAGGGTGTT) with highly resistant mutants may be used as genetic markers for early selection of resistant plants. (author)

  12. Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyrhizi syd)

    International Nuclear Information System (INIS)

    Ratma, R.

    1988-01-01

    Reaction of some soybean mutant lines to natural rust fungus caused by (phakopsora pachyhizi syd). Eleven soybean mutant lines of orba variety derived from gamma fungus disease in the wet season 1985/86 at the experimental station of Citayam, Bogor. Based on IWGSR rating system, soybean mutant lines No 18/PsJ was moderately resistant to rust fungus disease. The other mutant lines, 14/PsJ, 15/PsJ, 20/PsJ, 102/PsJ, 106/PsJ, 111/PsJ, 118/PsJ, 119/PsJ and 220/PsJ were susceptible. (author). 4 figs.; 8 refs

  13. Comparative study on nutritional quality and application value in three mutants of indigofera pseudotinctoria mats

    International Nuclear Information System (INIS)

    Mei Shufang; Mei Zhong; Zhao Hua; Huang Xin; Ye Hongxia; Shu Xiaoli; Wu Dianxing

    2013-01-01

    Major nutritional quality and values in purple-leaf, yellow-leaf and high flavone mutants of Indigofera pseudotinctoria Mats were investigated compared with the wild type. The content of protein in leaves of high flavone mutant was 26.45%, 24.31% higher than that of the wild type. The content of fiber in high flavone mutant was 18.92% lower than that of the wild type. The contents of Fe, Cu, Mn, Zn in high flavone mutant were increased by 72.34% , 7.02%, 21.01% and 38.75%, respectively. Contents of TAA and EAA in high flavone mutant were increase by 27.85% and 27.68%, respectively. The contents of protein in purple- and yellow-leaf mutants were lower than that of the wild types, and the contents of Ca in purple- and yellow-leaf mutants were increased by 15.22% and 25.46%. The results above indicated that high flavone mutant had high application values used as feed crop, while purple- and yellow-leaf mutants also had feeding values to some extent. (authors)

  14. Morphological mutants of Neurospora crassa: possible evidence of abnormal morphology due to changes in DNA composition

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, R K; Dutta, S.K. Ojha, M.

    1973-01-01

    DNA from seven experimentally induced morphological mutants and the wild type strain 74A of Neurospora crassa showed typical bimodal denaturation profiles in a Gilford 2400 spectrophotometer. The ''slime'' and ''ropy'' mutants showed a comparatively high proportion of A + T rich DNA sequences. Studies on thermal denaturation, percent hybridization, and thermal stability indicate the DNA sequences of the slime mutant were distinctly different from the normal genomes of parental DNA as well as other wild type DNAs. No such difference was noticed in any other mutant and natural isolate of the species N. crassa tested. These studies indicate possible correlation between a change in DNA nucleotide sequences and abnormal morphogenesis.

  15. Evaluation of Yield and Chemical Characteristics of some Peanut Mutants Induced by Gamma Irradiation

    International Nuclear Information System (INIS)

    Abd El-daem, G.A.; Anwar, M.M.

    2013-01-01

    This study was conducted to evaluate some promising mutants in peanut for yielding ability over three generation (M5, M6 and M7) and to evaluate yield attributes as will as chemical characteristics of these mutants in M7 generation induced by 100 Gy gamma radiation. The obtained results showed that the increase of yield / plot over three generation as a percentage of control was 5% for mutant 7, 10.2 % for mutant 10; 22% for mutant 9 and 22.9% for mutant 8. This increase in yield may be due to increase of one or more of yield attributes for most mutant lines. The significant increase for. No .of pods and seeds/ plant, weight of pods and seeds/ plant and 100- seed weight in M7 as compared to the control. For saturated fatty acid composition, results revealed that total saturated fatty acids ranged from 17.79% for mutant 8 to 21.75 for mutant 2 compared to 24.21% for control. Reduction of total saturated fatty acid was noticed for different mutants compared to that of the original variety. However, for total unsaturated fatty acids, results indicated that total unsaturated fatty acid composition ranged from 77.95% for mutant 9 to 82.09% for mutant 8 compared to 75.49% for control. Higher total unsaturated fatty acids for all mutant lines were obtained than that of the control, however, total saturated (TS)/ total unsaturated (TU) ratio was decreased for all mutants compared to control. The physical and chemical contents of Peanut oils showed that the refractive indices were ranged from 1.4620 to 1.4718 specific gravity were in range of 0.9146 to 0.9177. Acid value was range from 0.54 to 0.89% lodine value was ranged from 94.56 to 101.85. Saponification value was ranged from 185.2 to 190.7 and unsaponifiable matter was ranged from 0.98 to 1.33. The peroxide values ranged from 1.15 to 2.33 meq/kg oil. Also, fortified yoghurt made with replaced mutant peanut oil by 50% as milk fat substitute. Data showed that chemical composition and organolyptic properties had the

  16. Field Performance of Five Soybean Mutants Under Drought Stress Conditions and Molecular Analysis Using SSR Markers

    Directory of Open Access Journals (Sweden)

    Y Yuliasti

    2017-08-01

    Full Text Available The objectives of this research wereto evaluate (1 the performance of soybean mutant lines under drought stress conditions, and(2 the genetic diversity and relationship among the mutant lines using SSR markers.The field evaluation was conducted during the dry season of 2011 and 2012 at the experimental Farm of Mataram University, West Nusa Tenggara, Indonesia. The field experiment was set up in a randomized block design. Ten mutant lines and two control varieties were evaluated in four replications. Genetic distance among evaluated lines were determined based on allelic diversity analysis using 40 simple sequence repeat (SSR loci. Under drought stress conditions, two mutant lines, Kdl3 and Kdl8,showed a better performance compared to the other ones. The high yielding mutant lines were Kdl3and Kdl8, which yielded 1.75 t ha-1and 1.69 t ha-1, respectively, compared to the parent and national control, Panderman 1.43 t ha-1 and Muria 1.32 t ha-1. These mutant linesrequired 30.75 to 32days to flower and 79.75 to 83.75 day to harvest with relatively short plant height 28.25 and 23.35 cmrespectively. Those mutant characters were better than those of the other three mutants, the original parents, and the control soybean species. Since the evaluated soybean mutant lines yielded more under drought stress conditions than the standard varieties, they can be used and registered as drought-tolerant soybean mutants. Moreover, the evaluated soybean accessions showed a wide genetic distance. The accessions were clustered into two groups according to their genetic background, namelygroup I (the Panderman with three mutant lines and group II (the Muria with two mutant lines. Twenty-three out of 40 evaluated SSR loci, including AW31, BE806, CMAC7L, S080, S126, S57, S171, S224, S285, S294, S393, S294, S383, S511, S511, S520, S540, S547, S551, S571, S577, and S578, provided polymorphic alleles between the parents and their mutants and could be used to differentiate

  17. Genetic background of Prop1(df) mutants provides remarkable protection against hypothyroidism-induced hearing impairment.

    Science.gov (United States)

    Fang, Qing; Giordimaina, Alicia M; Dolan, David F; Camper, Sally A; Mustapha, Mirna

    2012-04-01

    Hypothyroidism is a cause of genetic and environmentally induced deafness. The sensitivity of cochlear development and function to thyroid hormone (TH) mandates understanding TH action in this sensory organ. Prop1(df) and Pou1f1(dw) mutant mice carry mutations in different pituitary transcription factors, each resulting in pituitary thyrotropin deficiency. Despite the same lack of detectable serum TH, these mutants have very different hearing abilities: Prop1(df) mutants are mildly affected, while Pou1f1(dw) mutants are completely deaf. Genetic studies show that this difference is attributable to the genetic backgrounds. Using embryo transfer, we discovered that factors intrinsic to the fetus are the major contributor to this difference, not maternal effects. We analyzed Prop1(df) mutants to identify processes in cochlear development that are disrupted in other hypothyroid animal models but protected in Prop1(df) mutants by the genetic background. The development of outer hair cell (OHC) function is delayed, but Prestin and KCNQ4 immunostaining appear normal in mature Prop1(df) mutants. The endocochlear potential and KCNJ10 immunostaining in the stria vascularis are indistinguishable from wild type, and no differences in neurofilament or synaptophysin staining are evident in Prop1(df) mutants. The synaptic vesicle protein otoferlin normally shifts expression from OHC to IHC as temporary afferent fibers beneath the OHC regress postnatally. Prop1(df) mutants exhibit persistent, abnormal expression of otoferlin in apical OHC, suggesting delayed maturation of synaptic function. Thus, the genetic background of Prop1(df) mutants is remarkably protective for most functions affected in other hypothyroid mice. The Prop1(df) mutant is an attractive model for identifying the genes that protect against deafness.

  18. Molecular analyses of in vivo hprt mutant T cells from atomic bomb survivors

    International Nuclear Information System (INIS)

    Hakoda, M.; Hirai, Y.; Kyoizumi, S.; Akiyama, M.

    1989-01-01

    In vivo-derived hprt-deficient mutant T cells isolated from three nonirradiated controls and two atomic bomb survivors were studied by Southern blot analysis to investigate the molecular spectra of the mutations. Mutant frequencies for the three controls were 1.8, 2.3, and 7.3 x 10(-6), and those for the two survivors (who had received radiation doses of 2.46 and 2.15 Gy, based upon the revised atomic bomb shielded kerma estimates) were 9.3 and 14.4 x 10(-6), respectively. Fourteen (13%) of 105 mutant T-cell colonies from the controls showed various structural changes in the hprt gene. The frequency of mutants with hprt gene structural changes in one atomic bomb survivor, who exhibited a mutant frequency of 9.3 x 10(-6), was 26% (16/61), which was significantly higher than that of the controls. However, the frequency of structural changes in the other survivor (14%, 8/59) was not higher than that of the controls. Two sets of mutants (in total, eight mutants) from the survivor, who showed a significantly higher frequency of mutants with hprt gross alterations than did the controls, had the same hprt changes and the same rearrangements of T-cell receptor (TcR) beta- and gamma-chain genes, indicating a clonal expansion from one progenitor mutant. This phenomenon may reflect an in vivo recovery process of T cells in the periphery after exposure to atomic bomb radiation. However, when comparing the frequency of mutations, these two sets of mutants should be reduced. After reducing the total number of mutants from the number of gross hprt changes, the frequency was not significantly higher than that of the controls

  19. Induced mutants of Streptococcus lactis by gamma irradiation and its effect on milk acidity

    International Nuclear Information System (INIS)

    Daowd, A.H.; Sabbour, M.M.; Newigy, N.A.; Wahab, G.A.M.

    1988-01-01

    Streptococus lactis was exposed to different doses of gamma-irradiation (10, 50, 100 and 150 Kr). The results of acidity production in sterilized milk inoculated by isolates from radiation treatments and control could be summarized in the following: 1. The mean acidity produced by S. lactis isolates after irradiation at 10 Kr increased to be 0.66% than that of control isolates (0.62%). The acidity produced by the isolates of the 50 Kr treatment showed more increment to reach the peak (0.7%). Thereafter, acidity production decreased by isolates of the 100 Kr (0.53%) and 150 Kr (0.51%) treatments. Heme, the 50 Kr treatment could be considered activation dose to S. lactis starter for acid production. 2. Two mutants were selected. Acidity production by mutant I (from 10 Kr treatment) was 0.95%, and that of mutant II (from 50 Kr treatment) was 1.0%, while acid production by the parent S. lactis culture was 0.62%. Concerning the stability of the isolates, it was found that acid production by mutant I and mutant II slightly decreased by time. The mutants were re-irradiated after 37 and 60 days at doses 10, 25 and 50 Kr. Acid production in milk by isolates of the radiation treatments was determined. The following results were obtained: -The re-irradiation of the mutants decreased the ability of the isolates for acid production than that of parent mutants. -The re-irradiation of the mutants after 60 days yielded isolates which showed more reduction in acid produced than of isolates obtained from re-irridation of the mutants after 37-days. -The higher the dose of the re-irradiation of the mutants, the lower the mean of acid production by isolates of the treatment

  20. Amyloplast displacement is necessary for gravisensing in Arabidopsis shoots as revealed by a centrifuge microscope.

    Science.gov (United States)

    Toyota, Masatsugu; Ikeda, Norifumi; Sawai-Toyota, Satoe; Kato, Takehide; Gilroy, Simon; Tasaka, Masao; Morita, Miyo Terao

    2013-11-01

    The starch-statolith hypothesis proposes that starch-filled amyloplasts act as statoliths in plant gravisensing, moving in response to the gravity vector and signaling its direction. However, recent studies suggest that amyloplasts show continuous, complex movements in Arabidopsis shoots, contradicting the idea of a so-called 'static' or 'settled' statolith. Here, we show that amyloplast movement underlies shoot gravisensing by using a custom-designed centrifuge microscope in combination with analysis of gravitropic mutants. The centrifuge microscope revealed that sedimentary movements of amyloplasts under hypergravity conditions are linearly correlated with gravitropic curvature in wild-type stems. We next analyzed the hypergravity response in the shoot gravitropism 2 (sgr2) mutant, which exhibits neither a shoot gravitropic response nor amyloplast sedimentation at 1 g. sgr2 mutants were able to sense and respond to gravity under 30 g conditions, during which the amyloplasts sedimented. These findings are consistent with amyloplast redistribution resulting from gravity-driven movements triggering shoot gravisensing. To further support this idea, we examined two additional gravitropic mutants, phosphoglucomutase (pgm) and sgr9, which show abnormal amyloplast distribution and reduced gravitropism at 1 g. We found that the correlation between hypergravity-induced amyloplast sedimentation and gravitropic curvature of these mutants was identical to that of wild-type plants. These observations suggest that Arabidopsis shoots have a gravisensing mechanism that linearly converts the number of amyloplasts that settle to the 'bottom' of the cell into gravitropic signals. Further, the restoration of the gravitropic response by hypergravity in the gravitropic mutants that we tested indicates that these lines probably have a functional gravisensing mechanism that is not triggered at 1 g. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  1. X-ray-sensitive mutants of Chinese hamster ovary cell line

    International Nuclear Information System (INIS)

    Jeggo, P.A.; Kemp, L.M.

    1983-01-01

    A standard technique of microbial genetics, which involves the transfer of cells from single colonies by means of sterile toothpicks, has been adapted to somatic cell genetics. Its use has been demonstrated in the isolation of X-ray-sensitive mutants of CHO cells. 9000 colonies have been tested and 6 appreciably X-ray-sensitive mutants were isolated. (D 10 values 5-10-fold of wild-type D 10 value.) A further 6 mutants were obtained which showed a slight level of sensitivity (D 10 values less than 2-fold of wild-type D 10 value). The 6 more sensitive mutants were also sensitive to bleomycin, a chemotherapeutic agent inducing X-ray-like damage. Cross-sensitivity to UV-irradiation and treatment with the alkylating agents, MMS, EMS and MNNG, was investigated for these mutants. Some sensitivity to these other agents was observed, but in all cases it was less severe than the level of sensitivity to X-irradiation. Each mutant showed a different overall response to the spectrum of agents examined and these appear to represent new mutant phenotypes derived from cultured mammalian cell lines. One mutant strain, xrs-7, was cross-sensitive to all the DNA-damaging agents, but was proficient in the repair of single-strand breaks. (Auth.)

  2. Comparison of arabidopsis stomatal density mutants indicates variation in water stress responses and potential epistatic effects

    Science.gov (United States)

    Shaneka S. Lawson; Paula M. Pijut; Charles H. Michler

    2014-01-01

    Recent physiological analysis of Arabidopsis stomatal density (SD) mutants indicated that SD was not the major factor controlling aboveground biomass accumulation. Despite the general theory that plants with fewer stomata have limited biomass acquisition capabilities, epf1 and several other Arabidopsis mutants varied significantly in leaf fresh...

  3. Screening of mutant strains producing phytase from A. niger by 60Co γ-ray irradiation

    International Nuclear Information System (INIS)

    Yang Pingping; Wang Yan; Tao Wenyi

    2004-01-01

    60 Co γ-ray was used to irradiate Aspergillus niger 447-92 for screening the mutant strain of producing phytase, and the effects of mutation induction were determined and analyzed. A mutant strain A. niger 496-1 with high level of phytase was selected, the phytase properties of A. niger 496-1 were analyzed

  4. Occurrence of toxicity among protease, amylase, and color mutants of a nontoxic soy sauce koji mold

    International Nuclear Information System (INIS)

    Kalayanamitr, A.; Bhumiratana, A.; Flegel, T.W.; Glinsukon, T.; Shinmyo, A.

    1987-01-01

    A soy sauce koji mold, Aspergillus flavus var. columnaris Raper and Fennel (ATCC 44310), was treated with UV irradiation to obtain mutant strains possessing high protease activities, high amylase activities, and light-colored conidia. Selected mutant strains were tested for toxicity, and some were found acutely toxic to weanling rats, although all were negative for aflatoxin production

  5. Increased riboflavin production from activated bleaching earth by a mutant strain of Ashbya gossypii.

    Science.gov (United States)

    Tajima, Satoshi; Itoh, Yoko; Sugimoto, Takashi; Kato, Tatsuya; Park, Enoch Y

    2009-10-01

    The production of riboflavin from vegetable oil was increased using a mutant strain of Ashbya gossypii. This mutant was generated by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Riboflavin production was 10-fold higher in the mutant compared to the wild-type strain. The specific intracellular catalase activity after 3 d of culture was 6-fold higher in the mutant than in the wild-type strain. For the mutant, riboflavin production in the presence of 40 mM hydrogen peroxide was 16% less than that in the absence of hydrogen peroxide, whereas it was 56% less for the wild-type strain. The isocitrate lyase (ICL) activity of the mutant was 0.26 mU/mg of protein during the active riboflavin production phase, which was 2.6-fold higher than the wild-type strain. These data indicate that the mutant utilizes the carbon flux from the TCA cycle to the glyoxylate cycle more efficiently than the wild-type strain, resulting in enhanced riboflavin production. This novel mutant has the potential to be of use for industrial-scale riboflavin production from waste-activated bleaching earth (ABE), thereby transforming a useless material into a valuable bioproduct.

  6. Isolation and characterization of Arabidopsis mutants with enhanced tolerance to oxidative stress

    NARCIS (Netherlands)

    Qureshi, Muhammad K.; Radeva, Vesela; Genkov, Todor; Minkov, Ivan; Hille, Jacques; Gechev, Tsanko S.; Liu, J.-H.

    We have previously reported a method for isolation of mutants with enhanced tolerance to the fungal AAL toxin and given a detailed characterization of atr1 (AAL toxin resistant, Gechev et al. in Biochem Biophys Res Commun 375:639-644, 2008). Herewith, we report eight more mutants with enhanced

  7. RECEPTOR POTENTIAL AND LIGHT-INDUCED MITOCHONDRIAL ACTIVATION IN BLOWFLY PHOTORECEPTOR MUTANTS

    NARCIS (Netherlands)

    MOJET, MH; TINBERGEN, J; STAVENGA, DG

    1991-01-01

    1. Simultaneous measurements of the receptor potential and the light-induced mitochondrial activation were performed in white-eyed blowflies Calliphora vicina, mutant chalky, and Lucilia cuprina, mutants w(F) and w'nss. The intensity dependence and the temporal dynamics were investigated. 2. The

  8. Characterization of Saccharomyces cerevisiae suppressor mutants devoid of the membrane lipid phosphatidylcholine

    NARCIS (Netherlands)

    Bao, X.

    2018-01-01

    Phosphatidylcholine (PC) is the most abundant membrane lipid in most eukaryotes and considered essential. The yeast double deletion mutant cho2opi3 lacks the methyltransferases converting phosphatidylethanolamine (PE) to PC. As a consequence, the cho2opi3 mutant is a choline auxotroph that relies on

  9. Selection of gamma-ray induced salt tolerant rice mutants by in vitro mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sub; Chun, Jae Beom; Lee, Kyung Jun; Kim, Jin Baek; Kim, Sang Hoon; Yun, Song Jong; Kang, Si Yong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-06-15

    The present study had been performed to select the salt tolerant rice mutant lines through an in vivo and in vitro mutagenesis with a gamma-ray. The physiological responses such as MDA and chlorophyll of the selected salt mutant lines were investigated under salt stress. For the selection of the salt tolerant rice mutants by in vitro mutagenesis with gamma-ray, we conducted a second selection procedure with 1,500 mutant lines induced from the original cv. Dongan (wild-type, WT): Ist, selection under a nutrient solution with 171 mM NaCI: 2nd, selection under in vitro conditions. Based on a growth comparison of the entries, out of mutant lines, the putative 2 salt tolerant rice mutant lines, ST-495 and ST-532, were selected. The 2 ST-lines had a lower malonaldehyde (MDA) contents than wild-type (WT) during salt stress. The survival rate of the WT, ST-495 and ST-532 were 36.6%, 70% and 50% in 171 mM NaCI, respectively. The chlorophyll and carotenoid contents were decreased more in a WT plant than the two selected mutant lines. These rice mutant lines will be released for cultivation at the reclaimed land and used as a control plot for genetic research about salt tolerance.

  10. A Ten-Week Biochemistry Lab Project Studying Wild-Type and Mutant Bacterial Alkaline Phosphatase

    Science.gov (United States)

    Witherow, D. Scott

    2016-01-01

    This work describes a 10-week laboratory project studying wild-type and mutant bacterial alkaline phosphatase, in which students purify, quantitate, and perform kinetic assays on wild-type and selected mutants of the enzyme. Students also perform plasmid DNA purification, digestion, and gel analysis. In addition to simply learning important…

  11. Characterization of mitomycin-C-sensitive mouse lymphoma L5178Y cell mutants

    International Nuclear Information System (INIS)

    Inaba, Hiroko; Shiomi, Naoko; Shiomi, Tadahiro; Sato, Koki; Yoshida, Michihiro.

    1985-01-01

    Twenty-six mutants showing high sensitivity to mytomicin-C (MMC) were isolated from mouse lymphoma L5178Y cells by a replica-plating technique. Twenty-five of the mutants were 5 - 10 times more sensitive to MMC than were parental cells, and showed normal sensitivity to U.V. light and x-rays. From a complementation analysis, 5 mutants (MC s ) isolated from independently mutagenized cell populations were classified into two groups. These mutants possessed recessive character for MMC-sensitivity and there were at least two genes involved in the MMC-sensitivity. As for DNA-damaging factors, such as photoadducts of 8-methoxypsoralen (8-MOP) and 3-carbethoxysoralen (3-CPs), MC s mutants showed higher sensitivity to photoadducts of 8-MOP than to (3-CPs). MC s mutants were also highly sensitive to a DNA cross-linking agent, cisplatin. Characterization of the sensitivity of mouse MC s mutants was analogous to that of Fanconi's anemia (FA)-derived cells. Low concentrations (10 ng/ml) of MMC induced chromosome aberration in a high incidence in mouse MC s cells, as well as in FA cells. The frequency of MMC-induced chromosome aberrations was normal in hybrid cells between normal human diploid somatic cells and mouse mutants and between FA cells and mouse wild cells, and hereditary deficiency became normal by hybrization. (Namekawa, K.)

  12. Mutant lines of currant tomato, valuable germplasm with multiple disease resistance

    International Nuclear Information System (INIS)

    Govorova, G.F.; Khrustaleva, V.V.; Shcherbakov, V.K.

    1987-01-01

    Studies were carried out for two years on eight mutant lines of currant tomato at the Krymsk Experimental Breeding Station of the N.I. Vavilov All-Union Scientific Research Institute of Plant-Growing (VIR). The station is situated in an area of commercial field tomato growing (Krasnodar region). The mutant lines of currant tomato (VIR specimen No. k-4053) were obtained through chronic gamma-irradiation. A disease resistance evaluation of the mutants was carried out for Verticillium wilt (Verticillium albo-atrum Rein. and Berth.), for black bacterial spotting (Xanthomonas vesicatoria Dows.), for tobacco mosaic virus Nicotiana 1 Smith), for streak virus (Nicotiana 1), for the combination TMV with X and Y potato viruses, for cucumber virus (Cucumis 1), and also for top rot. Fifty plants of each mutant line were evaluated and checks were made three times in each season. A comparison of the currant tomato mutants with the standard tomato varieties demonstrates the better resistance shown by the mutant germplasm to the main pathogens. The degree to which some currant tomato mutants were affected by Verticillium was lower than that of the most VerticiIlium-resistant samples of tomato evaluated between 1975 and 1981. The mutants of currant tomato should therefore be of interest as germplasm in breeding tomatoes for improved multiple disease resistance

  13. Phenotypic characterization of adenovirus type 12 temperature-sensitive mutants in productive infection and transformation.

    Science.gov (United States)

    Hama, S; Kimura, G

    1980-01-01

    Eleven temperature-sensitive mutants of adenovirus type 12, capable of forming plaques in human cells at 33 C but not at 39.5 C, were isolated from a stock of a wild-type strain after treatment with either nitrous acid or hydroxylamine. Complementation tests in doubly infected human cells permitted a tentative assignment of eight of these mutants to six complementation groups. Temperature-shift experiments revealed that one mutant is affected early and most of the other mutants are affected late. Only the early mutant, H12ts505, was temperature sensitive in viral DNA replication. Infectious virions of all the mutants except H12ts505 and two of the late mutants produced at 33 C, appeared to be more heat labile than those of the wild type. Only H12ts505 was temperature sensitive for the establishment of transformation of rat 3Y1 cells. One of the late mutants (H12ts504) had an increased transforming ability at the permissive temperature. Results of temperature-shift transformation experiments suggest that a viral function affected in H12ts505 is required for "initiation" of transformation. Some of the growth properties of H12ts505-transformed cells were also temperature dependent, suggesting that a functional expression of a gene mutation in H12ts505 is required to maintain at least some aspects of the transformed state.

  14. Characterization of Boerhavia diffusa L. mutant lines by RAPD and isozyme, selected for agronomically valuable traits

    International Nuclear Information System (INIS)

    Shukla, N.; Sangwan, N.S.; Misra, H.O.; Sangwan, R.S.

    2004-01-01

    Boerhavia diffusa is a medicinally important plant and finds extensive uses in traditional herbal drug preparations. For the development of improved varieties in terms of superior yield and quality of herb/root of B. diffusa, mutation breeding was attempted. Mutants generated by physical and chemical mutagenic treatments were screened for yield and quality parameters of the root/herb up to three consecutive generations. The selected-screened lines generated by physical and chemical mutagenic treatments on two selected genotypes I and II were molecularly analyzed using eight isozymes and eleven RAPD primers producing good amplification. Mutants from BD10 (selected genotype I) were distinct, while, in case of BD22 (selected genotype II), only one mutant BDMu7 was recorded distinct by isozyme analysis. The wild mutant (BDMu16, with maximum height and mouve coloured flower) was distinct in RAPD banding pattern. Isozymes differentiated the mutants from their respective controls, whereas RAPD differentiated the mutants and controls and also distinguished the mutants. The RAPD analysis was found to be better suited than isozymes for detecting genetic differences among controls and their mutants. However, both RAPD and isozyme analyses gave similar patterns of genetic relationships [it

  15. Selection of gamma-ray induced salt tolerant rice mutants by in vitro mutagenesis

    International Nuclear Information System (INIS)

    Kim, Dong Sub; Chun, Jae Beom; Lee, Kyung Jun; Kim, Jin Baek; Kim, Sang Hoon; Yun, Song Jong; Kang, Si Yong

    2010-01-01

    The present study had been performed to select the salt tolerant rice mutant lines through an in vivo and in vitro mutagenesis with a gamma-ray. The physiological responses such as MDA and chlorophyll of the selected salt mutant lines were investigated under salt stress. For the selection of the salt tolerant rice mutants by in vitro mutagenesis with gamma-ray, we conducted a second selection procedure with 1,500 mutant lines induced from the original cv. Dongan (wild-type, WT): Ist, selection under a nutrient solution with 171 mM NaCI: 2nd, selection under in vitro conditions. Based on a growth comparison of the entries, out of mutant lines, the putative 2 salt tolerant rice mutant lines, ST-495 and ST-532, were selected. The 2 ST-lines had a lower malonaldehyde (MDA) contents than wild-type (WT) during salt stress. The survival rate of the WT, ST-495 and ST-532 were 36.6%, 70% and 50% in 171 mM NaCI, respectively. The chlorophyll and carotenoid contents were decreased more in a WT plant than the two selected mutant lines. These rice mutant lines will be released for cultivation at the reclaimed land and used as a control plot for genetic research about salt tolerance

  16. Genetics and physiology of the nuclearly inherited yellow foliar mutants in soybean

    Science.gov (United States)

    Plant photosynthetic pigments are important in harvesting the light energy and transfer of energy during photosynthesis. There are several yellow foliar mutants discovered in soybean and chromosomal locations for about half of them have been deduced. Viable-yellow mutants are capable of surviving wi...

  17. Ensemble-based computational approach discriminates functional activity of p53 cancer and rescue mutants.

    Directory of Open Access Journals (Sweden)

    Özlem Demir

    2011-10-01

    Full Text Available The tumor suppressor protein p53 can lose its function upon single-point missense mutations in the core DNA-binding domain ("cancer mutants". Activity can be restored by second-site suppressor mutations ("rescue mutants". This paper relates the functional activity of p53 cancer and rescue mutants to their overall molecular dynamics (MD, without focusing on local structural details. A novel global measure of protein flexibility for the p53 core DNA-binding domain, the number of clusters at a certain RMSD cutoff, was computed by clustering over 0.7 µs of explicitly solvated all-atom MD simulations. For wild-type p53 and a sample of p53 cancer or rescue mutants, the number of clusters was a good predictor of in vivo p53 functional activity in cell-based assays. This number-of-clusters (NOC metric was strongly correlated (r(2 = 0.77 with reported values of experimentally measured ΔΔG protein thermodynamic stability. Interpreting the number of clusters as a measure of protein flexibility: (i p53 cancer mutants were more flexible than wild-type protein, (ii second-site rescue mutations decreased the flexibility of cancer mutants, and (iii negative controls of non-rescue second-site mutants did not. This new method reflects the overall stability of the p53 core domain and can discriminate which second-site mutations restore activity to p53 cancer mutants.

  18. Isolation of a Kluyveromyces fragilis derepressed mutant hyperproducer of inulinase for ethanol production from Jerusalem artichoke

    Energy Technology Data Exchange (ETDEWEB)

    Bourgi, J.; Guirand, J.P.; Galzy, P.

    1986-01-01

    A paritally derepressed mutant of Kluyveromyces fragilis showing hyperproduction of inulinase was isolated by means of ethylmethanesulfonate mutation followed by a 2-deoxyglucose selection. This mutant is suitable for the fermentation of inulin and Jerusalem artichoke extracts containing large amounts of inulin high polyfructosans type (early extracts).

  19. Immunohistochemical studies of lens crystallins in the dysgenetic lens (dyl) mutant mice

    NARCIS (Netherlands)

    Brahma, S.K.; Sanyal, S.

    1984-01-01

    The lens in the dyl mutant mice shows a persistent lens-ectodermal connection as well as degeneration and extrusion of lens materials after the initial differentiation of the fibres. Immunohistochemical investigation of the ontogeny of the lens crystallins in this developing mutant lens has been

  20. Variation of several agronomic and biochemical traits in γ-ray induced mutant soybeans

    International Nuclear Information System (INIS)

    Shim, Kyo Moon; Kim, Sun Hyung; Kim, Nam Soo; Son, Hi Sup; Rhee, Hae Ik

    1996-01-01

    Two soybean cultivars(Paldalkong and Bangsakong) were irradiated with gamma-ray to reduce seed size, which is an important trait for soybean sprout and the derived mutant soybeans were analyzed in several agronomic and biochemical traits. There were high levels of variations in quantitative traits among the mutants. Several mutant lines showed higher yield and smaller seed than their parents. Qualitative traits such as seed coat color or pubescent color were also changed in a few lines. Biochemical variations were also observed among the mutants. In seed storage protein analysis, many mutant lines showed reduced intensities in β-subunits in 7S globulin than their parents and an additional band in the acidic subunit at 31KDa. Two mutant lines derived from Paldalkong showed an additional band and a shifted band of protease inhibitor by electrophoretic analysis. Variations in isozymes and RAPD were also observed among the mutants. Six isozymes(Adh, Est, Gdh, Idh, Mdh and Pgm) among eleven isozymes showed some variations and six out of ten primers showed polymorphic amplified DNA fragments among the mutants. (author)

  1. Photosynthetic Characteristics of Flag Leaves in Rice White Stripe Mutant 6001 During Senescence Process

    Directory of Open Access Journals (Sweden)

    Xiao-hui ZHEN

    2014-11-01

    Full Text Available Physiological, biochemical and electron microscopy analyses were used to investigate the photosynthetic performance of flag leaves in rice white stripe mutant 6001 during the senescence process. Results showed that the chlorophyll content at the heading and milk-ripe stages in rice mutant 6001 were about 34.78% and 3.00% less than those in wild type 6028, respectively. However, the chlorophyll content at the fully-ripe stage in rice mutant 6001 was higher than that in wild type 6028. At the heading stage, the net photosynthetic rate (Pn in rice mutant 6001 was lower than that in wild type 6028. Rice mutant 6001 also exhibited a significantly slower decrease rate of Pn than wild type 6028 during the senescence progress, especially at the later stage. Furthermore, Ca2+-ATPase, Mg2+-ATPase and photophosphorylation activities exhibited the similar trends as the Pn. During the senescence process, the 68 kDa polypeptide concentrations in the thylakoid membrane proteins exhibited a significant change, which was one of the critical factors that contributed to the observed change in photosynthesis. We also observed that the chloroplasts of rice mutant 6001 exhibited higher integrity than those of wild type 6028, and the chloroplast membrane of rice mutant 6001 disintegrated more slow during the senescence process. In general, rice mutant 6001 had a relatively slower senescence rate than wild type 6028, and exhibited anti-senescence properties.

  2. Identical substitutions in magnesium chelatase paralogs result in chlorophyll deficient soybean mutants

    Science.gov (United States)

    The soybean (Glycine max (L.) Merr.) chlorophyll deficient line MinnGold is a spontaneous mutant characterized by yellow foliage. Map-based cloning and transgenic complementation revealed that the mutant phenotype is caused by a non-synonymous nucleotide substitution in the third exon of a Mg-chelat...

  3. Biodiversity in the cyclic competition system of three species according to the emergence of mutant species

    Science.gov (United States)

    Park, Junpyo

    2018-05-01

    Understanding mechanisms which promote or hinder existing ecosystems are important issues in ecological sciences. In addition to fundamental interactions such as competition and migration among native species, existing ecosystems can be easily disturbed by external factors, and the emergence of new species may be an example in such cases. The new species which does not exist in a current ecosystem can be regarded as either alien species entered from outside or mutant species born by mutation in existing normal species. Recently, as existing ecosystems are getting influenced by various physical/chemical external factors, mutation due to anthropogenic and environmental factors can occur more frequently and is thus attracting much attention for the maintenance of ecosystems. In this paper, we consider emergences of mutant species among self-competing three species in the cyclic dominance. By defining mutation as the birth of mutant species, we investigate how mutant species can affect biodiversity in the existing ecosystem. Through microscopic and macroscopic approaches, we have found that the society of existing normal species can be disturbed by mutant species either the society is maintained accompanying with the coexistence of all species or jeopardized by occupying of mutant species. Due to the birth of mutant species, the existing society may be more complex by constituting two different groups of normal and mutant species, and our results can be contributed to analyze complex ecosystems of many species. We hope our findings may propose a new insight on mutation in cyclic competition systems of many species.

  4. Expression of CALR mutants causes mpl-dependent thrombocytosis in zebrafish.

    Science.gov (United States)

    Lim, K-H; Chang, Y-C; Chiang, Y-H; Lin, H-C; Chang, C-Y; Lin, C-S; Huang, L; Wang, W-T; Gon-Shen Chen, C; Chou, W-C; Kuo, Y-Y

    2016-10-07

    CALR mutations are identified in about 30% of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and primary myelofibrosis. Although the molecular pathogenesis of CALR mutations leading to MPNs has been studied using in vitro cell lines models, how mutant CALR may affect developmental hematopoiesis remains unknown. Here we took advantage of the zebrafish model to examine the effects of mutant CALR on early hematopoiesis and model human CALR-mutated MPNs. We identified three zebrafish genes orthologous to human CALR, referred to as calr, calr3a and calr3b. The expression of CALR-del52 and CALR-ins5 mutants caused an increase in the hematopoietic stem/progenitor cells followed by thrombocytosis without affecting normal angiogenesis. The expression of CALR mutants also perturbed early developmental hematopoiesis in zebrafish. Importantly, morpholino knockdown of mpl but not epor or csf3r could significantly attenuate the effects of mutant CALR. Furthermore, the expression of mutant CALR caused jak-stat signaling activation in zebrafish that could be blocked by JAK inhibitors (ruxolitinib and fedratinib). These findings showed that mutant CALR activates jak-stat signaling through an mpl-dependent mechanism to mediate pathogenic thrombopoiesis in zebrafish, and illustrated that the signaling machinery related to mutant CALR tumorigenesis are conserved between human and zebrafish.

  5. High protein mutants of winter fodder barley induced by radiation and chemical mutagens

    Energy Technology Data Exchange (ETDEWEB)

    Yankulov, M.; Genchev, K.; Nikolov, Kh.

    1982-01-01

    Several induced mutants of winter fodder barley with higher rpotein content are described. These mutants were produced by treating seeds of cvs. Vogelsaenger Gold, Ager and 468 with gamma-rays, sodium azide and ethyl methanesulfonate (alone and in combinations) and with ethylene and formamide. The gamma-ray induced mutants of winter fodder barley have 1-4% higher protein content. The mutant line 109 has, besides high protein content (17,37%), 5.96 lysine per 100 g protein, but its endosperm is wrinkeled. Mutants produced by chemical mutagens have 6-7% higher protein content than the initial cultivars. All induced mutants have 85-95 cm high stems, i.e. they are by 10-20 cm shorter than the initial cultivars. Some of these mutants are now resistant to the diseases Helminthosporium gramineum and Ustilago nuda. The recommended mutants could be successfully used in breeding programs for producing of higher protein content and quality in winter fodder barley.

  6. High protein mutants of winter fodder barley induced by radiation and chemical mutagens

    International Nuclear Information System (INIS)

    Yankulov, M.; Genchev, K.; Nikolov, Kh.

    1982-01-01

    Several induced mutants of winter fodder barley with higher rpotein content are described. These mutants were produced by treating seeds of cvs. Vogelsaenger Gold, Ager and 468 with gamma-rays, sodium azide and ethyl methanesulfonate (alone and in combinations) and with ethylene and formamide. The gamma-ray induced mutants of winter fodder barley have 1-4% higher protein content. The mutant line 109 has, besides high protein content (17,37%), 5.96 lysine per 100 g protein, but its endosperm is wrinkeled. Mutants produced by chemical mutagens have 6-7% higher protein content than the initial cultivars. All induced mutants have 85-95 cm high stems, i.e. they are by 10-20 cm shorter than the initial cultivars. Some of these mutants are now resistant to the diseases Helminthosporium gramineum and Ustilago nuda. The recommended mutants could be successfully used in breeding programs for producing of higher protein content and quality in winter fodder barley

  7. Comparative production of cellulases by mutants of Trichoderma parceramosume PTCC5140

    Directory of Open Access Journals (Sweden)

    Hoda Nouri

    2017-06-01

    Discussion and conclusion: Evaluation of cellulase production in mutant strains of Trichoderma parceramosume PTCC 5140 showed that use of chemical mutagenesis with 2 to 11 fold increasing in enzyme activity is a potent method to improve cellulase complex activity. In the current study, obtained mutant strains could be introduced as a potent cellulase producer for further studies in bioconversion processes.

  8. Isolation and genetic analysis of amber uvrA and uvrB mutants

    International Nuclear Information System (INIS)

    Morimyo, M.; Shimazu, Y.; Ishii, N.

    1976-01-01

    Genetic properties of amber uvrA and uvrB mutants of Escherichia coli K-12 are described. The isolation of three amber uvrA and two amber uvrB mutants indicates that the products of these genes are proteins

  9. Twist1 suppresses senescence programs and thereby accelerates and maintains mutant Kras-induced lung tumorigenesis

    DEFF Research Database (Denmark)

    Tran, Phuoc T; Shroff, Emelyn H; Burns, Timothy F

    2012-01-01

    KRAS mutant lung cancers are generally refractory to chemotherapy as well targeted agents. To date, the identification of drugs to therapeutically inhibit K-RAS have been unsuccessful, suggesting that other approaches are required. We demonstrate in both a novel transgenic mutant Kras lung cancer...

  10. Temperature-Sensitive Mutants of Mouse Hepatitis Virus Strain A59: Isolation, Characterization and Neuropathogenic Properties.

    NARCIS (Netherlands)

    M.J.M. Koolen (Marck); A.D.M.E. Osterhaus (Albert); G. van Steenis (Bert); M.C. Horzinek; B.A.M. van der Zeijst (Ben)

    1983-01-01

    textabstractTwenty 5-fluorouracil-induced temperature-sensitive (ts) mutants of mouse hepatitis virus strain A59 were isolated from 1284 virus clones. Mutants were preselected on the basis of their inability to induce syncytia in infected cells at the restrictive temperature (40 degrees) vs the

  11. Alterations in biochemical and physiological characters in radiation-induced mutants of grain legumes

    International Nuclear Information System (INIS)

    Mueller, H.P.

    1984-01-01

    Selected examples from different grain legumes are studied. The biochemically and physiologically detectable alterations in distintc characters as caused by the action of mutant genes are presented comparatively. The interactions between different mutant genes in order to evaluated the influence of the genotypic constitution on the expression of mutated genes are emphasized. (M.A.C.) [pt

  12. Andrographolide induces degradation of mutant p53 via activation of Hsp70.

    Science.gov (United States)

    Sato, Hirofumi; Hiraki, Masatsugu; Namba, Takushi; Egawa, Noriyuki; Baba, Koichi; Tanaka, Tomokazu; Noshiro, Hirokazu

    2018-05-22

    The tumor suppressor gene p53 encodes a transcription factor that regulates various cellular functions, including DNA repair, apoptosis and cell cycle progression. Approximately half of all human cancers carry mutations in p53 that lead to loss of tumor suppressor function or gain of functions that promote the cancer phenotype. Thus, targeting mutant p53 as an anticancer therapy has attracted considerable attention. In the current study, a small-molecule screen identified andrographlide (ANDRO) as a mutant p53 suppressor. The effects of ANDRO, a small molecule isolated from the Chinese herb Andrographis paniculata, on tumor cells carrying wild-type or mutant p53 were examined. ANDRO suppressed expression of mutant p53, induced expression of the cyclin-dependent kinase inhibitor p21 and pro-apoptotic proteins genes, and inhibited the growth of cancer cells harboring mutant p53. ANDRO also induced expression of the heat-shock protein (Hsp70) and increased binding between Hsp70 and mutant p53 protein, thus promoting proteasomal degradation of p53. These results provide novel insights into the mechanisms regulating the function of mutant p53 and suggest that activation of Hsp70 may be a new strategy for the treatment of cancers harboring mutant p53.

  13. R Factor-Controlled Restriction and Modification of Deoxyribonucleic Acid: Restriction Mutants

    Science.gov (United States)

    Yoshimori, Robert; Roulland-Dussoix, Daisy; Boyer, Herbert W.

    1972-01-01

    Restriction mutants of two different R factor-controlled host specificities (RI and RII) were isolated. All of the restriction mutants examined had a normal modification phenotype. No complementation was observed between the RI and RII host specificities. It is concluded that for each host specificity no protein subunit is shared by the restriction endonuclease and modification methylase. PMID:4565538

  14. Chemical Excitation and Inactivation in Photoreceptors of the Fly Mutants trp and nss

    NARCIS (Netherlands)

    Suss, E.; Barash, S.; Stavenga, D.G.; Stieve, H.; Selinger, Z.; Minke, B.

    1989-01-01

    The Drosophila and Lucilia photoreceptor mutants, trp and nss, respond like wild-type flies to a short pulse of intense light or prolonged dim light; however, upon continuous intense illumination, the trp and nss mutants are unable to maintain persistent excitation. This defect manifests itself by a

  15. A chilling sensitive mutant of Arabidopsis with altered steryl-ester metabolism

    International Nuclear Information System (INIS)

    Hugly, S.; McCourt, P.; Somerville, C.; Browse, J.; Patterson, G.W.

    1990-01-01

    A chilling-sensitive mutant of Arabidopsis thaliana was isolated and subjected to genetic, physiological, and biochemical analysis. The chilling-sensitive nature of the mutant line is due to a single recessive nuclear mutation at a locus designated chs1. In contrast to wild-type plants, which are not adversely affected by low temperatures, the chs1 mutant is killed by several days of exposure to temperatures below 18 degree C. Following exposure to chilling temperatures, the mutant displays two common symptoms of chilling injury - leaf chlorosis and electrolyte leakage. In these respects, the physiological response of the mutant to low temperatures mimics the response observed in some naturally occurring chilling sensitive species. The biochemical basis of chilling sensitivity was explored by examining the pattern of incorporation of 14 CO 2 into soluble metabolites and lipids in wild-type and mutant plants. The only difference observed between the mutant and wild type was that following low temperature treatment, the mutant accumulated 10-fold more radioactivity in a specific class of neutral lipids which were identified by a variety of criteria to be steryl-esters. The accumulation of radioactivity in the steryl-ester fraction occurs 24 hours before there is any visible evidence of chilling injury

  16. Bridging the gap between chemistry, physiology, and evolution: Quantifying the functionality of sperm whale myoglobin mutants

    DEFF Research Database (Denmark)

    Dasmeh, Pouria; Kepp, Kasper Planeta

    2011-01-01

    This work merges a large set of previously reported thermochemical data for myoglobin (Mb) mutants with a physiological model of O2-transport and -storage. The model allows a quantification of the functional proficiency of myoglobin (Mb) mutants under various physiological conditions, i.e. O2-con...

  17. Induced mutants for the improvement of sesame and hybrid seed production

    International Nuclear Information System (INIS)

    Murty, G.S.S.

    2001-01-01

    With an overall objective to develop hybrids in sesame, induced mutants were used in cross breeding and five initial yield trials were conducted. For obtaining the mutant hybrids, recessive morphological mutants were used as female, and check varieties as male parents. In each trial, seed yields of mutant hybrids were compared with: i) the original parent in which the mutants were induced, ii) best check variety and iii) best cultivar hybrid. Among 138 mutant hybrids evaluated between 1994 and 1997, 18 showed superiority. In the development of hybrids, it is also desirable to have male sterile lines. By irradiating seeds with 400 Gy gamma rays, four genetic male sterile mutants were isolated. One of them, TMST-11 appears to be promising for breeding programme showing 100% male sterility and characterised by dark green foliage. To study the percent outcrossing, a monogenic chlorina mutant which can be identified from the seedling stage, was used in experiments conducted for two years. Among open pollinated plants, 92-98% plants were found outcrossed. Based on plant to row progenies, percent outcrossing ranged between 0.0 to 13.8%. (author)

  18. Structural basis for the changed substrate specificity of Drosophila melanogaster deoxyribonucleoside kinase mutant N64D

    DEFF Research Database (Denmark)

    Welin, M.; Skovgaard, T.; Knecht, Wolfgang

    2005-01-01

    The Drosophila melanogaster deoxyribonucleoside kinase (Dm-dNK) double mutant N45D/N64D was identified during a previous directed evolution study. This mutant enzyme had a decreased activity towards the natural substrates and decreased feedback inhibition with dTTP, whereas the activity with 3...

  19. Isolation and characterization of mutant strains of Escherichia coli altered in H2 metabolism

    International Nuclear Information System (INIS)

    Lee, J.H.; Patel, P.; Sankar, P.; Shanmugam, K.T.

    1985-01-01

    A positive selection procedure is described for the isolation of hydrogenase-defective mutant strains of Escherichia coli. Mutant strains isolated by this procedure can be divided into two major classes. Class II mutants produced hydrogenase activity (determined by using a tritium-exchange assay) and formate hydrogenlyase activity but lacked the ability to reduce benzyl viologen or fumarate with H 2 as the electron donor. Class I mutants failed to produce active hydrogenase and hydrogenase-dependent activities. All the mutant strains produced detectable levels of formate dehydrogenase-1 and -2 and fumarate reductase. The mutation in class I mutants mapped near 65 min of the E. coli chromosome, whereas the mutation in class II mutants mapped between srl and cys operons (58 and 59 min, respectively) in the genome. The class II Hyd mutants can be further subdivided into two groups (hydA and hydB) based on the cotransduction characteristics with cys and srl. These results indicate that there are two hyd operons and one hup operon in the E. coli chromosome. The two hyd operons are needed for the production of active hydrogenase, and all three are essential for hydrogen-dependent growth of the cell

  20. Molecular and biochemical analyses of spontaneous and X-ray-induced mutants in human lymphoblastoid cells

    Energy Technology Data Exchange (ETDEWEB)

    Liber, H L; Call, K M; Little, J B

    1987-05-01

    The authors have isolated a series of 14 spontaneously arising and 28 X-ray-induced mutants at the hypoxanthine-guanine phosphoribosyltransferase (hgprt) locus in human lymphoblastoid cells. Among the spontaneous mutants, 5/14 (36%) had detectable alterations in their restriction fragment pattern after hybridization with a human cDNA probe for hgprt. Of the 10 remaining mutants, 4 had partial HGPRT enzyme activity, which suggested that they contained point mutations. Among the 28 mutants induced by 150 rad of X-rays, 15 (54%) had deletions of part or all of the hgprt gene. Of the remaining 13 (18% overall) 5 had partial HGPRT enzyme activity, which suggested that they contained point mutations. These data imply that in this human cell system, X-rays induce both point mutants which have residual enzyme activity as well as mutations involving relatively large deletions of DNA. 48 reference, 1 figure, 4 tables.

  1. Isolation of L-methionine-enriched mutant of a methylotrophic yeast, Candida boidinii No.2201

    International Nuclear Information System (INIS)

    Tani, Y.; Lim, W.J.; Yang, H.C.

    1988-01-01

    Six strains of methylotrophic yeast were examined for production of L-methionine-enriched cells. Candida boidinii (kloeckera sp.) No. 2201,which accumulated 0.54 mg/g-dry cell weight (DCW) of free L-methionine (pool methionine), was selected as the parental strain for breeding L-methionine-rich mutants. Ethionine-resistant mutants were derived from the strain by UV irradiation. A mutant strain, E500-78,which was resistant to 500 μg/ml of DL-ethionine, accumulated 6.02 mg/g-DCW of pool methionine. The culture conditions for mutant strain E500-78 to increase pool methionine accumulation were optimized. As a result, the mutant strain accumulated 8.80 mg/g-DCW of pool methionine and contained 16.02 mg/g-DCW total methionine

  2. Studies on an X-ray induced crinkled leaf mutant of Trichosanthes anguina L

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Subodh Kumar

    1986-06-01

    Crinkled leaf mutant isolated in the second generation after treatment with X-ray bred true in subsequent generation. The mutant was a late flowering type with increased percentage of PMC's with chromosomal abnormality and pollen grain sterility. TLC study on phenolic compounds in leaves showed that both the mother line and the mutant had equal number of spots but they differed from each other with respect to four spots. Spot Nos. 2 and 4 of the mother line were absent in the mutant but the latter had two new spots (spot Nos. 11 and 12). The mutant and the mother line also differed from each other in pollen grain morohology. 3 figures, 2 tables, 4 refs.

  3. Further studies on a temperature-sensitive mutant of Escherichia coli with defective repair capacity

    International Nuclear Information System (INIS)

    Morfiadakis, I.; Geissler, E.; Akademie der Wissenschaften der DDR, Berlin. Zentralinstitut fuer Molekularbiologie)

    1981-01-01

    A temperature-sensitive mutant of E. coli, WG24, was studied with respect to its sensitivity to photodynamic action, its capacity to perform host controlled reactivation, and its sensitivity to transduction at elevated temperatures. Mutant cells are much more sensitive than wild type cells to photodynamic action by thiopyronine and visible light at elevated temperatures. As well defined rec mutants, WG24 cells are less able to reactivate UV irradiated lambdac phages at elevated temperatures, while their ability to repair T1 phages is less impaired. Mutant cells cannot be transduced to T6 resistance at a detectable rate at elevated temperature. It is concluded, therefore, that some rec gene carries a ts mutation in this mutant. (author)

  4. Inhibition of citric acid accumulation by manganese ions in Aspergillus niger mutants with reduced citrate control of phosphofructokinase

    Energy Technology Data Exchange (ETDEWEB)

    Schreferl, G.; Kubicek, C.P.; Roehr, M.

    1986-03-01

    Mutant strains of Aspergillus niger with reduced citrate control of carbohydrate catabolism (cic mutants) grow faster than the parent strain on media containing 5% (wt/vol) citrate. The mutants tolerated a higher intracellular citrate concentration than the parent strain. One mutant (cic-7/3) contained phosphofructokinase activity significantly less sensitive towards citrate than the enzyme from the parent strain. When this mutant was grown under citrate accumulating conditions, acidogenesis was far less sensitive to inhibition by Mn/sup 2 +/ than in the parent strain. Some of the cic mutants also showed altered citrate inhibition of NADP-specific isocitrate dehydrogenase.

  5. Seedless induced mutant in highly seeded lemon (Citrus limon)

    International Nuclear Information System (INIS)

    Spiegel-Roy, P.; Vardi, Aliza; Elhanati, A.

    1990-01-01

    Full text: We have reported earlier on the induction of a seedless mutant in ''Eureka'' lemon. Further irradiation work with gamma rays was performed with another lemon cultivar, ''Israeli Villafranca''. This highly prolific cultivar has usually up to 25 seeds per fruit. Budwood of ''Villafranca'' was exposed to 50 Gy gamma rays from a Co source at the Nuclear Soreq Centre (by courtesy of Mr. R. Padova). Buds from M 1 V 1 plants (usually buds 3 to 15) were individually budded in the nursery on sour orange, as well as buds from non-irradiated material. Out of 120 M 1 V 2 plants grown in the field at 3x2 m spacing one tree bore completely seedless fruit. Fruit on adjacent trees had 22 seeds on the average. The selected tree has been observed for two seasons and found to bear normal seedless fruit. M 1 V 3 trees from budwood of the selected original tree have been raised. Some of these have started bearing. Nearly all fruits are completely seedless, with a maximum number of 1 seed per fruit. (author)

  6. Analysis of MINT hibiscus rosa-sinensis mutants

    International Nuclear Information System (INIS)

    Shakinah Salleh; Shuhaimi Shamsudin; Putri Noor Faizah MM Tahir; Mohd Nazir Basiran

    2006-01-01

    Gamma irradiation is an alternative method to create new cultivars of Hibiscus rosa-sinensis in Malaysia. Increasing gamma ray doses resulted in a reduction of growing shoots on the irradiated stem cuttings. The LD50 for the stem cuttings was 36.2 Gy and at 75% growth was 17.15 Gy. Based on these results, 20 to 30 Gy were chosen for irradiation of the stem cuttings to induce mutation in Hibiscus rosa-sinensis. Irradiated stem cuttings were then planted into sand-beds for rooting. After one month, the rooted stems were transferred into polybags and allowed to grow under 70% shade provided by plastic netting and the variants were subsequently observed. Three new cultivars with variations in flower size and colours were obtained. The plants were propagated for five generations to achieve the stable mutants. Anthocyanins analysis is being carried out to measure the amount of anthocyanins in each cultivar. Pelargonidin chloride, Cyanidin chloride and Delphinidin chloride are used as standards for the analysis. (Author)

  7. Parameters of mitotic recombination in minute mutants of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Ferrus, A.

    1975-01-01

    A sample of 16 Minutes, representing 12 loci distributed over all the chromosome arms and including 3 pairs of alleles and 4 deficiencies, has been studied with respect to several developmental and recombinational parameters. Cell marker mutants located in most of the chromosome arms were used to assess (1) spontaneous and x-ray-induced mitotic recombination frequencies of each Minute, and (2) clone sizes of the different cell marker clones. These parameters were analyzed both in the wing disc and in the abdominal histoblasts. Whereas spontaneous frequencies are not affected by the presence of the Minutes studied, the different Minutes characteristically increase the frequency of recombination clones arising after x irradiation. The recombinant clones which are M + /M + are significantly larger than clones in the same fly which retain the M + /M condition. This is particularly striking in clones in the wing disc, slightly so in clones in the tergites. The occurrence of mitotic recombination in the fourth chromosome is reported for the first time. Chaeta length and developmental delay correlates with the recombinational parameters in different ways. Possible causal interrelationships of the different traits of the Minute syndrome are discussed. (U.S.)

  8. Characterization of an MMS sensitive mutant of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Martin, P.S.

    1979-01-01

    We have characterized a methyl methanesulfonate sensitive mutant of the yeast Saccharomyces cerevisiae in order to learn more about DNA repair and mutagenesis in this organism. The mutation, designated mms3-1, also confers sensitivity to ultraviolet light and to ethyl methanesulfonate in both haploids and homozygous diploids. Its effect on γ-ray sensitivity, however, is a function of the ploidy of the cell and its effect on induced mutation is a function of both the ploidy of the cell and the nature of the inducing agent. Our major findings are discussed. Our data indicate that: (1) Saccharomyces cerevisiae has an error prone pathway for the repair of uv damage controlled by the MMS3 gene product operating in and only in, and possibly induced by conditions present only in, a/α diploids; (2) in diploids, at least, there exists at least one step in the error prone repair of uv induced damage which is different from a step in the error prone repair of EMS induced damage; (3) a/α mms3-1/mms3-1 diploids may be defective in a step common to the repair of mutagenic lesions following uv irradiation and lethal lesions following γ irradiation; and (4) there are steps in the repair of MMS induced lethal damage that are different from steps in the repair of EMS induced lethal damage

  9. Transcriptional dysregulation in NIPBL and cohesin mutant human cells.

    Directory of Open Access Journals (Sweden)

    Jinglan Liu

    2009-05-01

    Full Text Available Cohesin regulates sister chromatid cohesion during the mitotic cell cycle with Nipped-B-Like (NIPBL facilitating its loading and unloading. In addition to this canonical role, cohesin has also been demonstrated to play a critical role in regulation of gene expression in nondividing cells. Heterozygous mutations in the cohesin regulator NIPBL or cohesin structural components SMC1A and SMC3 result in the multisystem developmental disorder Cornelia de Lange Syndrome (CdLS. Genome-wide assessment of transcription in 16 mutant cell lines from severely affected CdLS probands has identified a unique profile of dysregulated gene expression that was validated in an additional 101 samples and correlates with phenotypic severity. This profile could serve as a diagnostic and classification tool. Cohesin binding analysis demonstrates a preference for intergenic regions suggesting a cis-regulatory function mimicking that of a boundary/insulator interacting protein. However, the binding sites are enriched within the promoter regions of the dysregulated genes and are significantly decreased in CdLS proband, indicating an alternative role of cohesin as a transcription factor.

  10. IDH1 mutant negative ganglioglioma progression to gliosarcoma

    Directory of Open Access Journals (Sweden)

    Liming Qiu

    2017-09-01

    Full Text Available Gangliogliomas comprise of less than 1% of all primary brain tumours. Malignant transformation is rare. Correspondingly, secondary gliosarcomas, especially in the absence of previous irradiation exposure is too, exceedingly rare. Recent evidence supports the use of mutant IDH1 testing in suspected adult gangliogliomas as a distinguishing feature between ganglioglioma and early diffuse astrocytoma. The authors report a case of a ganglioglioma (WHO I in the cingulate gyrus that underwent malignant transformation and propagated into a multi-lesional gliosarcoma (WHO IV glioblastoma variant. A previously well 59-year-old lady presented with first-onset focal seizures secondary to a left cingulate gyrus lesion. Stereotactic biopsy of the lesion demonstrated an IDH1 (R132H ganglioglioma. The patient remained well until a routine follow-up MRI performed 36 months later showed significant progression of the initial lesion and a new, separate lesion in the left temporoparietal lobe. Surgical excision was performed. The final histology reported a gliosarcoma. In view of the unusual findings, the case is reviewed corroboratively with current disease understanding.

  11. An Inactive Geminin Mutant That Binds Cdt1

    Directory of Open Access Journals (Sweden)

    Marissa Suchyta

    2015-05-01

    Full Text Available The initiation of DNA replication is tightly regulated in order to ensure that the genome duplicates only once per cell cycle. In vertebrate cells, the unstable regulatory protein Geminin prevents a second round of DNA replication by inhibiting the essential replication factor Cdt1. Cdt1 recruits mini-chromosome maintenance complex (MCM2-7, the replication helicase, into the pre-replication complex (pre-RC at origins of DNA replication. The mechanism by which Geminin inhibits MCM2-7 loading by Cdt1 is incompletely understood. The conventional model is that Geminin sterically hinders a direct physical interaction between Cdt1 and MCM2-7. Here, we describe an inactive missense mutant of Geminin, GemininAWA, which binds to Cdt1 with normal affinity yet is completely inactive as a replication inhibitor even when added in vast excess. In fact, GemininAWA can compete with GemininWT for binding to Cdt1 and prevent it from inhibiting DNA replication. GemininAWA does not inhibit the loading of MCM2-7 onto DNA in vivo, and in the presence of GemininAWA, nuclear DNA is massively over-replicated within a single S phase. We conclude that Geminin does not inhibit MCM loading by simple steric interference with a Cdt1-MCM2-7 interaction but instead works by a non-steric mechanism, possibly by inhibiting the histone acetyltransferase HBO1.

  12. The Succinated Proteome of FH-Mutant Tumours

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    Ming Yang

    2014-08-01

    Full Text Available Inherited mutations in the Krebs cycle enzyme fumarate hydratase (FH predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC. Loss of FH activity in HLRCC tumours causes accumulation of the Krebs cycle intermediate fumarate to high levels, which may act as an oncometabolite through various, but not necessarily mutually exclusive, mechanisms. One such mechanism, succination, is an irreversible non-enzymatic modification of cysteine residues by fumarate, to form S-(2-succinocysteine (2SC. Previous studies have demonstrated that succination of proteins including glyceraldehyde 3-phosphate dehydrogenase (GAPDH, kelch-like ECH-associated protein 1 (KEAP1 and mitochondrial aconitase (ACO2 can have profound effects on cellular metabolism. Furthermore, immunostaining for 2SC is a sensitive and specific biomarker for HLRCC tumours. Here, we performed a proteomic screen on an FH-mutant tumour and two HLRCC-derived cancer cell lines and identified 60 proteins where one or more cysteine residues were succinated; 10 of which were succinated at cysteine residues either predicted, or experimentally proven, to be functionally significant. Bioinformatic enrichment analyses identified most succinated targets to be involved in redox signaling. To our knowledge, this is the first proteomic-based succination screen performed in human tumours and cancer-derived cells and has identified novel 2SC targets that may be relevant to the pathogenesis of HLRCC.

  13. Mitotic chromosome transmission fidelity mutants in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Spencer, F.; Gerring, S.L.; Connelly, C.; Hieter, P.

    1990-01-01

    The authors have isolated 136 independent EMS-induced mutations in haploid yeast strains that exhibit decreased chromosome transmission fidelity in mitosis. Eight-five percent of the mutations are recessive and 15% are partially dominant. Complementation analysis between MATa and MATα isolates identifies 11 chromosome transmission fidelity (CTF) complementation groups, the largest of which is identical to CHL1. For 49 independent mutations, no corresponding allele has been recovered in the opposite mating type. The initial screen monitored the stability of a centromere-linked color marker on a nonessential yeast chromosome fragment; the mitotic inheritance of natural yeast chromosome III is also affected by the ctf mutations. Of the 136 isolates identified, seven were inviable at 37 degree and five were inviable at 11 degree. In all cases tested, these temperature conditional lethalities cosegregated with the chromosome instability phenotype. Five additional complementation groups (ctf12 through ctf16) have been defined by complementation analysis of the mutations causing inviability at 37 degree. All of the mutant strains showed normal sensitivity to ultraviolet and γ-irradiation

  14. Isolating human DNA repair genes using rodent-cell mutants

    International Nuclear Information System (INIS)

    Thompson, L.H.; Weber, C.A.; Brookman, K.W.; Salazar, E.P.; Stewart, S.A.; Mitchell, D.L.

    1987-01-01

    The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab

  15. Natural variation of model mutant phenotypes in Ciona intestinalis.

    Directory of Open Access Journals (Sweden)

    Paolo Sordino

    Full Text Available BACKGROUND: The study of ascidians (Chordata, Tunicata has made a considerable contribution to our understanding of the origin and evolution of basal chordates. To provide further information to support forward genetics in Ciona intestinalis, we used a combination of natural variation and neutral population genetics as an approach for the systematic identification of new mutations. In addition to the significance of developmental variation for phenotype-driven studies, this approach can encompass important implications in evolutionary and population biology. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report a preliminary survey for naturally occurring mutations in three geographically interconnected populations of C. intestinalis. The influence of historical, geographical and environmental factors on the distribution of abnormal phenotypes was assessed by means of 12 microsatellites. We identified 37 possible mutant loci with stereotyped defects in embryonic development that segregate in a way typical of recessive alleles. Local populations were found to differ in genetic organization and frequency distribution of phenotypic classes. CONCLUSIONS/SIGNIFICANCE: Natural genetic polymorphism of C. intestinalis constitutes a valuable source of phenotypes for studying embryonic development in ascidians. Correlating genetic structure and the occurrence of abnormal phenotypes is a crucial focus for understanding the selective forces that shape natural finite populations, and may provide insights of great importance into the evolutionary mechanisms that generate animal diversity.

  16. Mutants of Agrobacterium tumefaciens with elevated vir gene expression

    International Nuclear Information System (INIS)

    Pazour, G.J.; Ta, C.N.; Das, A.

    1991-01-01

    Expression of Agrobacterium tumefaciens virulence (vir) genes requires virA, virG, and a plant-derived inducing compound such as acetosyringone. To identify the critical functional domains of virA and virG, a mutational approach was used. Agrobacterium A136 harboring plasmid pGP159, which contains virA, virG, and a reporter virB:lacZ gene fusion, was mutagenized with UV light or nitrosoguanidine. Survivors that formed blue colonies on a plate containing 5-bromo-4-chloro-3-indolyl beta-D-galactoside were isolated and analyzed. Quantification of beta-galactosidase activity in liquid assays identified nine mutant strains. By plasmid reconstruction and other procedures, all mutations mapped to the virA locus. These mutations caused an 11- to 560-fold increase in the vegetative level of virB:lacZ reporter gene expression. DNA sequence analysis showed that the mutations are located in four regions of VirA: transmembrane domain one, the active site, a glycine-rich region with homology to ATP-binding sites, and a region at the C terminus that has homology to the N terminus of VirG

  17. Natural Variation of Model Mutant Phenotypes in Ciona intestinalis

    Science.gov (United States)

    Brown, Euan R.; Leccia, Nicola I.; Squarzoni, Paola; Tarallo, Raffaella; Alfano, Christian; Caputi, Luigi; D'Ambrosio, Palmira; Daniele, Paola; D'Aniello, Enrico; D'Aniello, Salvatore; Maiella, Sylvie; Miraglia, Valentina; Russo, Monia Teresa; Sorrenti, Gerarda; Branno, Margherita; Cariello, Lucio; Cirino, Paola; Locascio, Annamaria; Spagnuolo, Antonietta; Zanetti, Laura; Ristoratore, Filomena

    2008-01-01

    Background The study of ascidians (Chordata, Tunicata) has made a considerable contribution to our understanding of the origin and evolution of basal chordates. To provide further information to support forward genetics in Ciona intestinalis, we used a combination of natural variation and neutral population genetics as an approach for the systematic identification of new mutations. In addition to the significance of developmental variation for phenotype-driven studies, this approach can encompass important implications in evolutionary and population biology. Methodology/Principal Findings Here, we report a preliminary survey for naturally occurring mutations in three geographically interconnected populations of C. intestinalis. The influence of historical, geographical and environmental factors on the distribution of abnormal phenotypes was assessed by means of 12 microsatellites. We identified 37 possible mutant loci with stereotyped defects in embryonic development that segregate in a way typical of recessive alleles. Local populations were found to differ in genetic organization and frequency distribution of phenotypic classes. Conclusions/Significance Natural genetic polymorphism of C. intestinalis constitutes a valuable source of phenotypes for studying embryonic development in ascidians. Correlating genetic structure and the occurrence of abnormal phenotypes is a crucial focus for understanding the selective forces that shape natural finite populations, and may provide insights of great importance into the evolutionary mechanisms that generate animal diversity. PMID:18523552

  18. Producing Conditional Mutants for Studying Plant Microtubule Function

    Energy Technology Data Exchange (ETDEWEB)

    Richard Cyr

    2009-09-29

    The cytoskeleton, and in particular its microtubule component, participates in several processes that directly affect growth and development in higher plants. Normal cytoskeletal function requires the precise and orderly arrangement of microtubules into several cell cycle and developmentally specific arrays. One of these, the cortical array, is notable for its role in directing the deposition of cellulose (the most prominent polymer in the biosphere). An understanding of how these arrays form, and the molecular interactions that contribute to their function, is incomplete. To gain a better understanding of how microtubules work, we have been working to characterize mutants in critical cytoskeletal genes. This characterization is being carried out at the subcellular level using vital microtubule gene constructs. In the last year of funding colleagues have discovered that gamma-tubulin complexes form along the lengths of cortical microtubules where they act to spawn new microtubules at a characteristic 40 deg angle. This finding complements nicely the finding from our lab (which was funded by the DOE) showing that microtubule encounters are angle dependent; high angles encounters results in catastrophic collisions while low angle encounters result in favorable zippering. The finding of a 40 deg spawn of new microtubules from extant microtubule, together with aforementioned rules of encounters, insures favorable co-alignment in the array. I was invited to write a New and Views essay on this topic and a PDF is attached (News and Views policy does not permit funding acknowledgments and so I was not allowed to acknowledge support from the DOE).

  19. Evaluation of the combining ability of mutant maize lines

    Directory of Open Access Journals (Sweden)

    V. Valkova

    2016-09-01

    Full Text Available Abstract. The study shows the results of a preliminary evaluation of the combining ability for grain yield of 17 mutant maize lines. For the purpose the top cross method for early testing and the mathematical model of Savchenko for analysis of the general and the specific combining ability were used. The lines were tested on three testers with high general combining ability that belong to two genetic groups: K 46 52 and XM 552 from SSS and N 192 – Lancaster. For the purposes of evaluation of the productive abilities of the received top cross two preliminary varietal experiments were carried out at the experimental field of Maize Research Institute, Knezha As a result of the conducted experimental work and the analysis it was found that the highest general combining ability have lines XM 11 6 and XM 12 1. These lines can be included as components of high-yielding synthetics or as testers in analyzing crosses to determine general combining ability in early stages of the selection process. The above lines with high specific combining ability – XM 11 13 and XM 11 46 are suitable for inclusion in combinations to develop high-yielding hybrids. Three of the tested lines XM 11 7 11 XM 10 and XM 11 11 have both high GCA and SCA. These lines can be used in corresponding breeding in the selection programs.

  20. Genetic screens to identify new Notch pathway mutants in Drosophila.

    Science.gov (United States)

    Giagtzoglou, Nikolaos

    2014-01-01

    Notch signaling controls a wide range of developmental processes, including proliferation, apoptosis, and cell fate specification during both development and adult tissue homeostasis. The functional versatility of the Notch signaling pathway is tightly linked with the complexity of its regulation in different cellular contexts. To unravel the complexity of Notch signaling, it is important to identify the different components of the Notch signaling pathway. A powerful strategy to accomplish this task is based on genetic screens. Given that the developmental context of signaling is important, these screens should be customized to specific cell populations or tissues. Here, I describe how to perform F1 clonal forward genetic screens in Drosophila to identify novel components of the Notch signaling pathway. These screens combine a classical EMS (ethyl methanesulfonate) chemical mutagenesis protocol along with clonal analysis via FRT-mediated mitotic recombination. These F1 clonal screens allow rapid phenotypic screening within clones of mutant cells induced at specific developmental stages and in tissues of interest, bypassing the pleiotropic effects of isolated mutations. More importantly, since EMS mutations have been notoriously difficult to map to specific genes in the past, I briefly discuss mapping methods that allow rapid identification of the causative mutations.