Restriction of phage T4 internal protein I mutants by a strain of Escherichia coli

International Nuclear Information System (INIS)

Black, L.W.; Abremski, K.

1974-01-01

Phage T4 internal protein I(IPI), a small (ca, 10,000 MW), basic protein injected into the host with the phage DNA, is not required for infection of most hosts, but mutants defective in IPI are restricted by at least one naturally occurring strain of Escherichia coli, CT 596 (CT). Phages lacking IPI (IPI - ) appear to inject their DNA and bind it to the membrane of CT cells as well as wild-type phage T4 does, but shutoff of host protein synthesis, initiation of T4 protein synthesis, and cell killing are abnormal in the IPI - mutant infected CT host. The injection of IPI appears to be important in allowing T4 DNA to carry out early steps involved in takeover of this host. Restriction of IPI - phage growth by CT cells appears to be due, at least in part, to a defective prophage it harbors which renders the host resistant to successful infection by phage T4 which lack IPI or rII functions. Bacteria cured of this prophage can be infected by mutants defective in these functions. The resistance of CT cells to other coliphages, and the question of T-even phage internal protein diversity are discussed. (U.S.)

Hormonal control of seed development in gibberellin- and ABA-deficient tomato (Lycopersicon esculentum Mill. cv. Moneymaker) mutants

NARCIS (Netherlands)

Castro, de R.D.; Hilhorst, H.W.M.

2006-01-01

Developing seeds of tomato gibberellin (GA)-deficient gib1 and abscisic acid (ABA)-deficient sitw mutants enabled us to analyze the role of GA in the regulation of embryo histo-differentiation, and the role of ABA in the regulation of maturation and quiescence. Our data show that DNA synthesis and

Chemical analysis of a polysaccharide of unripe (green) tomato (Lycopersicon esculentum).

Science.gov (United States)

Chandra, Krishnendu; Ghosh, Kaushik; Ojha, Arnab K; Islam, Syed S

2009-11-02

A polysaccharide (PS-I) isolated from the aqueous extract of the unripe (green) tomatoes (Lycopersicon esculentum) consists of D-galactose, D-methyl galacturonate, D-arabinose, L-arabinose, and L-rhamnose. Structural investigation of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments the structure of the repeating unit of the polysaccharide (PS-I) was established as: [structure: see text].

Tomato bushy stunt virus (TBSV) infecting Lycopersicon esculentum.

Science.gov (United States)

Hafez, El Sayed E; Saber, Ghada A; Fattouh, Faiza A

2010-01-01

Tomato bushy stunt virus (TBSV) was detected in tomato crop (Lycopersicon esculentum) in Egypt with characteristic mosaic leaf deformation, stunting, and bushy growth symptoms. TBSV infection was confirmed serologically by ELISA and calculated incidence was 25.5%. Basic physicochemical properties of a purified TBSV Egh isolate were identical to known properties of tombusviruses of isometric 30-nm diameter particles, 41-kDa coat protein and the genome of approximately 4800 nt. This is the first TBSV isolate reported in Egypt. Cloning and partial sequencing of the isolate showed that it is more closely related to TBSV-P and TBSV-Ch than TBSV-Nf and TBSV-S strains of the virus. However, it is distinct from the above strains and could be a new strain of the virus which further confirms the genetic diversity of tombusviruses.

Herpetomonas spp. isolated from tomato fruits (Lycopersicon esculentum) in southern Spain.

Science.gov (United States)

Marín, Clotilde; Fabre, Sandrine; Sánchez-Moreno, Manuel; Dollet, Michel

2007-05-01

A flagellate of the family Trypanosomatidae was isolated from fruits of Lycopersicon esculentum (tomato) in southeastern Spain. The isolate was successfully adapted to in vitro culture in monophasic media. The morphology showed the kinetoplast to be positioned towards the middle of the body, and the typical opistomastigote form characteristic of members of the genus Herpetomonas. Amplification of the mini-exon gene was negative, whilst for the 5S ribosomal rRNA gene the result was positive. The DNA sequence was obtained and its alignment with other trypasomatids, obtained using the BLAST algorithm, suggested it was closely related to Herpetomonas samuelpessoai.

Capítulo V: evaluación de especies silvestres de Lycopersicon sp. como fuente de resistencia al insecto plaga Scrobipalpula absoluta (Meyrick y su intento de transferencia a Lycopersicon esculentum Mill

Directory of Open Access Journals (Sweden)

Vallejo Cabrera Franco Alirio

1994-12-01

Full Text Available

En condiciones de campo, se evaluaron 32 introducciones silvestres de Lycopersicon sp. y una de la especie cultivada, L. esculentum Mill, con el fin de determinar la resistencia a Scrobipalpula absoluta (Meyrick. Se utilizó el diseño experimental bloques completos al azar con 4 repeticiones. Como bordes se colocaron tres variedades comerciales susceptibles al insecto (Chonto "Mata Verde", Napoli Y Chonto "Santa Cruz Kada" con el fin de tener una fuente de infestación natural y permanente del cogollero dentro del experimento. Se evaluaron los caracteres número de cogollos afectados, número de hojas dañadas, número de ampollas e intensidad de daño. Todas las introducciones de L. hirsutum y L. peruvianum fueron altamente resistentes. Las introducciones 1406 y 1407 de L. pimpinellifolium también fueron altamente resistentes. La introducción 1759 de L. esculentum y L. esculentum var. ceraciforme fueron muy susceptibles. Las introducciones de L. pimpinellifolium y L. hirsutum no tuvieron dificultad para hibridarse con L. esculentum var. Tropic. El cruzamiento L. esculentum x L. peruvianum no presentó semilla híbrida y se requirió efectuar cultivo de embriones inmaduros, in vitro, utilizando el medio Murashige & Skoog pero sin lograrse resultados positivos.

Thirty two (32 wild accessions of Lycopersicon sp. and one (1 cultivated accession of Lycopersicon esculentum Mill were evaluated to determinate the resistance to Scrobipalpula absoluta (Meyrick. The experiment was conducted with a complete random design and four repetitions. Three (3 susceptibles cultivated accessions of L. esculentum (Chonto "Mata Verde", Napoli and Chonto "Santa Cruz Kada" were sowed to have natural infestation of S. absoluta. Damage intensity, number of buds damaged, number of leaves demaged and number of "blister" in the leaves were evaluated, All evaluated accessions of L. peruvianum showed heigh resistence. 1406 and 1407 accessions of L. pimpinellifolium

Genotype dependant callogenic and morphogenic response of lycopersicon esculentum hybrids

International Nuclear Information System (INIS)

Jatoi, S.A.; Sajid, G.M.; Ahmad, S.; Anwar, R.; Munir, M.

2002-01-01

Leaf explants from field grown F1 hybrids of Lycopersicon esculentum, namely Bornia and Royesta were cultured on MS media containing 5 x 5 diallelic combinations of IAA and Kin at 0, 4, 8, 12 and 16 micro M/l each. Callogenesis, root and shoot regeneration potential of these hybrids were compared on these hormonal regimes. Royesta exhibited better callogenesis response (85%) than Bornia (72%). However, callogenesis on a given hormonal regime was genotype dependant. Root and shoot regeneration was better in case of Bornia than in Royesta. Hybrid Bornia produced shoots much more frequently (6-14%) on many diverse hormonal regimes than Royesta which produced shoots only rarely (5%) on a single hormonal regime. (author)

Tomato ( Lycopersicon esculentum ) seeds: new flavonols and cytotoxic effect.

Science.gov (United States)

Ferreres, Federico; Taveira, Marcos; Pereira, David M; Valentão, Patrícia; Andrade, Paula B

2010-03-10

In this study, seeds of Lycopersicon esculentum Mill. were analyzed by HPLC/UV-PAD/MS(n)-ESI. Fourteen flavonoids were identified, including quercetin, kaempferol, and isorhamnetin derivatives, with 13 of them being reported for the first time in tomato seeds. The major identified compounds were quercetin-3-O-sophoroside, kaempferol-3-O-sophoroside, and isorhamnetin-3-O-sophoroside. A significant cell proliferation inhibition (>80%), against rat basophile leukemia (RBL-2H3) cell line, was observed with this extract (IC(50) = 5980 microg/mL). For acetylcholinesterase inhibitory activity, a concentration-dependent effect was verified (IC(20) = 2400 microg/mL). The same behavior was noted regarding antioxidant capacity, evaluated against DPPH (IC(10) = 284 microg/mL), nitric oxide (IC(25) = 396 microg/L), and superoxide radicals (IC(25) = 3 microg/mL).

Capítulo IV: caracterización morfo-agronómica de especies y variedades botánicas del genero Lycopersicon

Directory of Open Access Journals (Sweden)

Arango Angel Pedro A.

1994-12-01

Full Text Available

En condiciones de invernadero se renovó la semilla de 58 introducciones del género Lycopersicon. En condiciones de campo se evaluaron cerca de 30 plantas de cada una de las introducciones viables. Además, se realizaron 5 cruzamientos, incluyendo los recíprocos, entre cada una de las introducciones viables y las variedades experimentales Chonto-109 y Napoli-1457. De 58 introducciones solo 16 produjeron semilla viable (L. hirsutum-1408, L. glandulusum   1403 y 1404, L. peruvianum-613 y 1409, L. pimpinellifolium-615, L. esculentum-633, L. pennelli- 632, L. esculentum var. ceraciforme- 183, 616. 923, 1140, 1506 Y 1508, L. esculentum varo grandifolium -1217, L. esculentum validum- 1110. Hubo gran variabilidad en emergencia, precocidad, duración de cosecha, cuajamiento de flores, rendimiento y sus componentes, análisis físico-químico de frutos entre las diferentes introducciones. L. peruvianum- 613 y 1409, L. glandulosum- 1403 y 1404 y L. pimpinellifolium 615 presentaron poco ataque de Scrobipalpula absoluta. Las variedades botánicas de L. esculentum presentaron mayores eficiencias de cruzamiento (84.3 % que las especies de Lycopersicon (27.7 %, cuyas eficiencias fueron: L. esculentum (75%, L. pimpinellifolium (50%, L. hirsutum (40%, L. glandulosum (5% y L. peruvianum (2.5%.

The seeds from 58 introductions of the genus Lycopersicon were multiplied in the glasshouse. Thirty seeding of each introductions producing germinated seed were planted for to observe the characteristics of agronomical interest. Five reciprocal crosses were made with two experimental varieties (Chonto-1091 and Napoli-1457 with the purpose of to study the crossing efficiency of the introductions. From 58 introductions planted on1y 16 produced germinated seeds (L. hirsutum- 1408, L. g1andulosum- 1403 y 1404, L. peruvianum-613 y 1409 L. pimpinellifolium- 615, L. esculentum-633 S. pennelli- 632 L. esculentum var. ceraciforme- 183, 616. 923, 1140, 1506 y 1508 L

TAI vacuolar invertase orthologs: the interspecific variability in tomato plants (Solanum section Lycopersicon).

Science.gov (United States)

Slugina, M A; Shchennikova, A V; Kochieva, E Z

2017-10-01

Understanding the genetic mechanisms underlying carbohydrate metabolism can promote the development of biotechnological advances in fruit plants. The flesh tomato fruit represents an ideal system for examining the role of sucrose cleavage enzymes in fruit development, and wild tomato species differing in storage sugars serve as an excellent research material for this purpose. Plant vacuolar invertase is a key enzyme of sucrose metabolism in the sink organs. In the present study, we identified complete gene sequences encoding the TAI vacuolar invertase in 11 wild and one cultivated tomato accessions of the Solanum section Lycopersicon. The average level of interspecific polymorphism in TAI genes was 8.58%; however, in the green-fruited tomatoes, the TAI genes contained 100 times more SNPs than those in the red-fruited accessions. The TAI proteins demonstrated 8% variability, whereas the red-fruited species had none. A TAI-based phylogenetic tree revealed two main clusters containing self-compatible and self-incompatible species, which concurs with the previous crossability-based division and demonstrates that the TAI genes reflect the evolutionary relationships between the red- and green-fruited tomatoes. Furthermore, we detected differential expression patterns of the TAI genes in the fruits of wild and cultivated tomatoes, which corresponded to sugar composition. The polymorphism analysis of the TAI acid invertases of Solanum section Lycopersicon species will contribute to the understanding of the genetic potential of TAI genes to impact tomato breeding through genetic engineering of the carbohydrate composition in the fruit.

Inhibition of Cholinesterases and Some Pro-Oxidant induced Oxidative Stress in Rats Brain by Two Tomato (Lycopersicon Esculentum) Varieties

Science.gov (United States)

Oboh, G.; Bakare, O.O.; Ademosun, A.O.; Akinyemi, A.J.; Olasehinde, T.A.

2015-01-01

This study sought to investigate the effects of two tomato varieties [Lycopersicon esculentum Mill. var. esculentum (ESC) and Lycopersicon esculentum Mill. var. cerasiforme (CER)] on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in vitro. Phenolics content, carotenoids characterisation, inhibition of Fe2+ and quinolinic acid-induced malondialdehyde (MDA) production in rats brain homogenate and NO* scavenging abilities were also assesed in addition to the AChE and BChE inhibition assays. There was no significant difference in the AChE inhibitory ability of the samples, while CER had significantly higher BChE inhibitory activity. Furthermore, the tomatoes inhibited Fe2+ and quinolinic acid-induced MDA production and further exhibited antioxidant activities through their NO* scavenging abilities. There was no significant difference in the phenolic content of the samples, while significantly high amounts of lycopene were detected in the tomatoes. The cholinesterase-inhibition and antioxidant properties of the “tomatoes” could make them good dietary means for the management of neurodegenerative disorders.

Abscisic Acid Accumulation by Roots of Xanthium strumarium L. and Lycopersicon esculentum Mill. in Relation to Water Stress.

Science.gov (United States)

Cornish, K; Zeevaart, J A

1985-11-01

Plants of Xanthium strumarium L. and Lycopersicon esculentum Mill. cv ;Rheinlands Ruhm' were grown in solution culture, and control and steam-girdled intact plants were stressed. Detached roots of both species were stressed to different extents in two ways: (a) either in warm air or, (b) in the osmoticum Aquacide III. The roots of both species produced and accumulated progressively more abscisic acid (ABA), the greater the stress inflicted by either method. ABA-glucose ester levels in Xanthium roots were not affected by water stress and were too low to be the source of the stress-induced ABA. The fact that ABA accumulated in detached roots and in roots of girdled plants proves that ABA was synthesized in the roots and not merely transported from the shoots.Maximum ABA accumulation in detached roots occurred after 60 to 70% loss of fresh weight. In Xanthium roots, ABA levels continued to increase for at least 11 hours, and no catabolism was apparent when stressed roots were immersed in water, although the roots did stop accumulating ABA. When osmotically stressed, Xanthium roots reached a maximum ABA level after 2 hours, but ABA continued to rise in the medium.Under optimal stress conditions, endogenous ABA levels increased 100 times over their prestress values in detached roots of Xanthium, and 15 times in Lycopersicon under nonoptimal stress, when endogenous ABA was expressed as concentrations based on tissue water content. These are much greater relative increases than observed in the leaves (15 times in Xanthium, 3 times in Lycopersicon), although the roots contain substantially less ABA than the leaves in all circumstances. The results suggest that the endogenous level of ABA in roots could rise appreciably prior to leaf wilt, and could modify the plant's water economy before the leaves become stressed.

Estudios de eficacia de trichoderma cepa G008 sobre el complejo “marchitez del tomate” (lycopersicon esculentum mill)

OpenAIRE

Cevallos Maridueña, Soraya Efigenia

2010-01-01

El tomate Lycopersicon esculentum Mill., es uno de los cultivos de importancia económica entre las hortalizas en Ecuador. Datos estadísticos en el país del año 2006 dan a conocer que la superficie sembrada con tomate fue 677.59 ha, con una producción de 1848.123 Tm (INEC, 2006).

Abscisic Acid Accumulation by Roots of Xanthium strumarium L. and Lycopersicon esculentum Mill. in Relation to Water Stress 1

Science.gov (United States)

Cornish, Katrina; Zeevaart, Jan A. D.

1985-01-01

Plants of Xanthium strumarium L. and Lycopersicon esculentum Mill. cv `Rheinlands Ruhm' were grown in solution culture, and control and steam-girdled intact plants were stressed. Detached roots of both species were stressed to different extents in two ways: (a) either in warm air or, (b) in the osmoticum Aquacide III. The roots of both species produced and accumulated progressively more abscisic acid (ABA), the greater the stress inflicted by either method. ABA-glucose ester levels in Xanthium roots were not affected by water stress and were too low to be the source of the stress-induced ABA. The fact that ABA accumulated in detached roots and in roots of girdled plants proves that ABA was synthesized in the roots and not merely transported from the shoots. Maximum ABA accumulation in detached roots occurred after 60 to 70% loss of fresh weight. In Xanthium roots, ABA levels continued to increase for at least 11 hours, and no catabolism was apparent when stressed roots were immersed in water, although the roots did stop accumulating ABA. When osmotically stressed, Xanthium roots reached a maximum ABA level after 2 hours, but ABA continued to rise in the medium. Under optimal stress conditions, endogenous ABA levels increased 100 times over their prestress values in detached roots of Xanthium, and 15 times in Lycopersicon under nonoptimal stress, when endogenous ABA was expressed as concentrations based on tissue water content. These are much greater relative increases than observed in the leaves (15 times in Xanthium, 3 times in Lycopersicon), although the roots contain substantially less ABA than the leaves in all circumstances. The results suggest that the endogenous level of ABA in roots could rise appreciably prior to leaf wilt, and could modify the plant's water economy before the leaves become stressed. PMID:16664467

The 7B-1 mutant in tomato shows blue-light-specific resistance to osmotic stress and abscisic acid.

Science.gov (United States)

Fellner, Martin; Sawhney, Vipen K

2002-03-01

Germination of wild-type (WT) tomato ( Lycopersicon esculentum Mill.) seed is inhibited by mannitol (100-140 mM) in light, but not in darkness, suggesting that light amplifies the responsiveness of the seed to osmotic stress (M. Fellner, V.K. Sawhney (2001) Theor Appl Genet 102:215-221). Here we report that white light (W) and especially blue light (B) strongly enhance the mannitol-induced inhibition of seed germination, and that the effect of red light (R) is weak or nil. The inhibitory effect of mannitol could be completely overcome by fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, indicating that mannitol inhibits seed germination via ABA accumulation in seeds. The inhibition of WT seed germination by exogenous ABA was also amplified by W or B, but not by R. In a recessive, ABA-overproducing, 7B-1 mutant of tomato, seed germination and hypocotyl growth were resistant to inhibition by mannitol or exogenous ABA, both in W or B. Experiments with fluridone suggested that inhibition of hypocotyl growth by W or B is also partially via ABA accumulation. De-etiolation in the mutant was especially less in B compared to the WT, and there was no difference in hypocotyl growth between the two genotypes in R. Our data suggest that B amplifies the responsiveness of tomato seeds and hypocotyls to mannitol and ABA, and that W- or B-specific resistance of the 7B-1 mutant to osmotic stress or ABA is a consequence of a defect in B perception or signal transduction.

Identification of the pI 4.6 extensin peroxidase from Lycopersicon esculentum using proteomics and reverse-genomics

OpenAIRE

Dong, Wen; Kieliszewski, Marcia; Held, Michael A.

2014-01-01

The regulation of plant cell growth and early defense response involves the insolubilization of hydroxyproline-rich glycoproteins (HRGPs), such as extensin, in the primary cell wall. In tomato (Lycopersicon esculentum), insolublization occurs by the formation of tyrosyl-crosslinks catalyzed specifically by the pI 4.6 extensin peroxidase (EP). To date, neither the gene encoding EP nor the protein itself has been identified. Here, we’ve identified tomato EP candidates using both proteomic and b...

Effect of glutathione on phytochelatin synthesis in tomato cells. [Lycopersicon esculentum

Energy Technology Data Exchange (ETDEWEB)

Mendum, M.L.; Gupta, S.C.; Goldsbrough, P.B. (Purdue Univ., West Lafayette, IN (USA))

1990-06-01

Growth of cell suspension cultures of tomato, Lycopersicon esculentum Mill. cv VFNT-Cherry, in the presence of cadmium is inhibited by buthionine sulfoximine, an inhibitor of glutathione synthesis. Cell growth and phytochelatin synthesis are restored to cells treated with buthionine sulfoximine by the addition of glutathione to the medium. Glutathione stimulates the accumulation of phytochelatins in cadmium treated cells, indicating that availability of glutathione can limit synthesis of these peptides. Exogenous glutathione causes a disproportionate increase in the level of smaller phytochelatins, notably ({gamma}-Glu-Cys){sub 2}-Gly. In the presence of buthionine sulfoximine and glutathione, phytochelatins that are produced upon exposure to cadmium incorporate little ({sup 35}S)cysteine, indicating that these peptides are probably not synthesized by sequential addition of cysteine and glutamate to glutathione.

Original Research

African Journals Online (AJOL)

2013-09-18

Sep 18, 2013 ... on Vegetative Growth, Fruit Anatomy and Seed Setting of Tomato. (Lycopersicon .... have effects on seed germination, shoot and root growth, side branch ...... development of tomato: Studies with a gibberellin- deficient mutant.

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.

Gamma radiation induced cytological abnormalities in Lycopersicon esculentum Mill. var. pusa ruby

Energy Technology Data Exchange (ETDEWEB)

Jayabalan, N.; Rao, G.R.

1987-03-01

Healthy dry seeds of pusa ruby variety of Lycopersicon esculentum Mill. were irradiated with gamma rays at 10 KR, 20 KR, 30 KR, 40 KR and 50 KR dose levels. Meiotic studies were made in treated plants as well as in control plants. At metaphase I, meiotic abnormalities like clumping and stickiness of chromosomes, univalents, multivalents, fragments and irregular grouping of chromosomes were observed. At anaphase I, there were laggards and unequal grouping of chromosomes at poles. Germination percentage and pollen fertility were also studied. Pollen sterility seems to be the cumulative result of various abnormal meiotic stages as well as of physiological and genetic damages induced probably by breakage of chromosomes. The frequency of meiotic abnormalities with reference to the effect of radiation doses is discussed.

Phosphate Starvation Inducible Metabolism in Lycopersicon esculentum1

Science.gov (United States)

Goldstein, Alan H.; Baertlein, Dawn A.; McDaniel, Robert G.

1988-01-01

Both tomato (Lycopersicon esculentum cv VF 36) plants and suspension cultured cells show phosphate starvation inducible (psi) excretion of acid phosphatase (Apase). Apase excretion in vitro was proportional to the level of exogenous orthophosphate (Pi). Intracellular Apase activity remained the same in both Pi-starved and sufficient cells, while Apase excreted by the starved cells increased by as much as six times over unstressed control cells on a dry weight basis. At peak induction, 50% of total Apase was excreted. Ten day old tomato seedlings grown without Pi showed slight growth reduction versus unstressed control plants. The Pi-depleted roots showed psi enhancement of Apase activity. Severely starved seedlings (17 days) reached only one-third of the biomass of unstressed control plants but, because of a combination of psi Apase excretion by roots and a shift in biomass to this organ, they excreted 5.5 times the Apase activity of the unstressed control. Observed psi Apase excretion may be part of a phosphate starvation rescue system in plants. The utility of the visible indicator dye 5-bromo-4-chloro-3-indolyl-phosphate-p-toluidine as a phenotypic marker for plant Apase excretion is demonstrated. Images Fig. 5 PMID:16666212

Gamma radiation induced cytological abnormalities in Lycopersicon esculentum Mill. var. pusa ruby

International Nuclear Information System (INIS)

Jayabalan, N.; Rao, G.R.

1987-01-01

Healthy dry seeds of pusa ruby variety of Lycopersicon esculentum Mill. were irradiated with gamma rays at 10 KR, 20 KR, 30 KR, 40 KR and 50 KR dose levels. Meiotic studies were made in treated plants as well as in control plants. At metaphase I, meiotic abnormalities like clumping and stickiness of chromosomes, univalents, multivalents, fragments and irregular grouping of chromosomes were observed. At anaphase I, there were laggards and unequal grouping of chromosomes at poles. Germination percentage and pollen fertility were also studied. Pollen sterility seems to be the cumulative result of various abnormal meiotic stages as well as of physiological and genetic damages induced probably by breakage of chromosomes. The frequency of meiotic abnormalities with reference to the effect of radiation doses is discussed. (author)

Desenvolvimento de protocolo para microenxertia do tomateiro Lycopersicon esculentum Mill = Developmental of protocol for micrograffiting to tomato Lycopersicon esculentum Mill

Directory of Open Access Journals (Sweden)

Luciano Façanha Marques

2010-01-01

Full Text Available A murcha bacteriana, causada por Ralstonia solanacearum, é a principal doença vascular de plantas em todo o mundo. O agente causal é uma bactéria que ocorre em todas as regiões do Brasil, predominando em condições de umidade e temperatura elevadas, fatores propícios aodesenvolvimento do patógeno. Este agente causal é de difícil controle, pois sobrevive nos mais diversos hospedeiros, especialmente Solanaceas, além de outras famílias de importância alimentar, condimentar e medicinal. O uso de espécies do gênero Solanum na enxertia convencional e minienxertia em tomateiro Lycopersicon esculentum é limitada em função da incompatibilidade. Neste trabalho, utilizou-se o método da microenxertia para obtenção de plantas resistentes a doenças como a murcha bacteriana, tendo como cavalo a espécie Solanum palinacanthum Dun. Utilizaram-se dois métodos de microenxertia: convencional em T-invertido e corte em bisel. Foram testados meios de culturas para execução das duas práticas demicropropagação; para isso, realizou-se experimento em diferentes condições ambientais, com presença e ausência de luminosidade e diferentes tratamentos correspondentes a teores de açúcares e sais, submetidos a cinco avaliações com intervalos semanais. Melhor resultado foi encontrado quando se utilizou microenxertia em T-invertido e meio de cultura constituído de sais de MS1/8 de força acrescido de 30 g L-1 de sacarose.The bacterial wilt, caused by Ralstonia solanacearum, is the most important vascular disease among plants in the world. The causal agent is a strain of bacteria found in all regions of Brazil, mainly in places with high humidity and temperature. This bacterium is difficult to control with chemical products, being able to survive in diverse hosts, especially in species of Solanaceae as well as other families of great food, condimental, or medicinal importance. The use of species of the genus Solanum has been attempted, but the

Photomorphogenic responses to UV radiation III: a comparative study of UVB effects on anthocyanin and flavonoid accumulation in wild-type and aurea mutant of tomato (Lycopersicon esculentum Mill.)

International Nuclear Information System (INIS)

Brandt, K.; Giannini, A.; Lercari, B.

1995-01-01

The UV-mediated induction of anthocyanin and UV-absorbing compounds was characterized in etiolated hypocotyls of wild-type and aurea (au) mutant tomato seedlings. Ultraviolet radiation induced significant increases of anthocyanin and UV-absorbing compounds in hypocotyls of the au mutant and of its isogenic wild-type, but the differences in the time courses of UV-induced pigment accumulation indicate that different photoregulatory mechanisms are involved for each of these two groups of pigments. It appears that prolonged presence of adequate levels of UVB (290-320 nm) energy and consequently the action of a specific UVB photoreceptor are indispensable for the photoinduction of anthocyanin accumulation in UV-irradiated hypocotyl of the au mutant that is missing the labile phytochrome pool. The large difference found between the wild-type and the au mutant strongly indicate the involvement of labile phytochrome as the primary functional photoreceptor for the photoinduction of anthocyanin accumulation in wild-type tomato hypocotyls. (author)

Effect of textile waste water on tomato plant, Lycopersicon esculentum.

Science.gov (United States)

Marwari, Richa; Khan, T I

2012-09-01

In this study Sanganer town, Jaipur was selected as study area. The plants of Lycopersicon esculentum var. K 21(Tomato) treated with 20 and 30% textile wastewater were analyzed for metal accumulation, growth and biochemical parameters at per, peak and post flowering stages. Findings of the study revealed that chlorophyll content was most severely affected with the increase in metal concentration. Total chlorophyll content showed a reduction of 72.44% while carbohydrate, protein and nitrogen content showed a reduction of 46.83, 71.65 and 71.65% respectively. With the increase in waste water treatment the root and shoot length, root and shoot dry weight and total dry weight were reduced to 50.55, 52.06, 69.93, 72.42, 72.10% respectively. After crop harvesting, the fruit samples of the plants treated with highest concentration of textile waste water contained 2.570 mg g(-1)d.wt. of Zn, 0.800 mg g(-1) d.wt. Cu, 1.520 mg g(-1) d.wt. Cr and 2.010 mg g(-1) d.wt. Pb.

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.

Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings

OpenAIRE

Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

2017-01-01

Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H2O2) under chilling stress conditions using tomato seedlings [(Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 2...

Jasmonic acid is a key regulator of spider mite-induced volatile terpenoid and methyl salicylate emission in tomato

NARCIS (Netherlands)

Ament, K.; Kant, M.R.; Sabelis, M.W.; Haring, M.A.; Schuurink, R.C.

2004-01-01

The tomato (Lycopersicon esculentum) mutant def-1, which is deficient in induced jasmonic acid (JA) accumulation upon wounding or herbivory, was used to study the role of JA in the direct and indirect defense responses to phytophagous mites (Tetranychus urticae). In contrast to earlier reports,

Acetylcholine causes rooting in leaf explants of in vitro raised tomato (Lycopersicon esculentum Miller) seedlings.

Science.gov (United States)

Bamel, Kiran; Gupta, Shrish Chandra; Gupta, Rajendra

2007-05-30

The animal neurotransmitter acetylcholine (ACh) induces rooting and promotes secondary root formation in leaf explants of tomato (Lycopersicon esculentum Miller var. Pusa Ruby), cultured in vitro on Murashige and Skoog's medium. The roots originate from the midrib of leaf explants and resemble taproot. ACh at 10(-5) M was found to be the optimum over a wide range of effective concentrations between 10(-7) and 10(-3) M. The breakdown products, choline and acetate were ineffective even at 10(-3) M concentration. ACh appears to have a natural role in tomato rhizogenesis because exogenous application of neostigmine, an inhibitor of ACh hydrolysis, could mimic the effect of ACh. Neostigmine, if applied in combination with ACh, potentiated the ACh effect.

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.

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)

Arthrobotrys oligospora-mediated biological control of diseases of tomato (Lycopersicon esculentum Mill.) caused by Meloidogyne incognita and Rhizoctonia solani.

Science.gov (United States)

Singh, U B; Sahu, A; Sahu, N; Singh, R K; Renu, S; Singh, D P; Manna, M C; Sarma, B K; Singh, H B; Singh, K P

2013-01-01

To study the biocontrol potential of nematode-trapping fungus Arthrobotrys oligospora in protecting tomato (Lycopersicon esculentum Mill.) against Meloidogyne incognita and Rhizoctonia solani under greenhouse and field conditions. Five isolates of the nematode-trapping fungus Arthrobotrys oligospora isolated from different parts of India were tested against Meloidogyne incognita and Rhizoctonia solani in tomato (Lycopersicon esculentum Mill.) plants grown under greenhouse and field conditions. Arthrobotrys oligospora-treated plants showed enhanced growth in terms of shoot and root length and biomass, chlorophyll and total phenolic content and high phenylalanine ammonia lyase activity in comparison with M. incognita- and R. solani-inoculated plants. Biochemical profiling when correlated with disease severity and intensity in A. oligospora-treated and untreated plants indicate that A. oligospora VNS-1 offered significant disease reduction in terms of number of root galls, seedling mortality, lesion length, disease index, better plant growth and fruit yield as compared to M. incognita- and R. solani-challenged plants. The result established that A. oligospora VNS-1 has the potential to provide bioprotection agents against M. incognita and R. solani. Arthrobotrys oligospora can be a better environment friendly option and can be incorporated in the integrated disease management module of crop protection. Application of A. oligospora not only helps in the control of nematodes but also increases plant growth and enhances nutritional value of tomato fruits. Thus, it proves to be an excellent biocontrol as well as plant growth promoting agent. © 2012 The Society for Applied Microbiology.

Atividade moluscicida de princípios ativos de folhas de Lycopersicon esculentum (Solanales, Solanaceae em Biomphalaria glabrata (Gastropoda, Planorbidae Moluscicide activity of active principles in the leaves of Lycopersicon esculentum (Solanales, Solanaceae on Biomphalaria glabrata (Gastropoda, Planorbidae

Directory of Open Access Journals (Sweden)

Vilma Leyton

Full Text Available Foram obtidos extratos aquosos e alcoólicos a partir de pó de folhas secas de tomateiro (Lycopersicon esculentum, Mill. c.v. Cereja. Por extração metanólica e precipitação alcalina, foi obtido um produto que denominamos "glicoalcalóide esteroidal bruto" (GEb, no qual foi caracterizada a presença de tomatina. Em ensaios laboratoriais, os extratos aquosos, alcoólicos e o GEb apresentaram atividade moluscicida em Biomphalaria glabrata (Say, 1818. O "glicoalcalóide esteroidal bruto" apresentou alta atividade moluscicida (CL50 = 8,01 ppm e CL90 = 13,17 ppm, comparável à atividade da tomatina. Desovas de B. glabrata mostraram-se resistentes aos extratos testados. Os níveis de atividade moluscicida apresentados pelos diversos extratos e o GEb, apontam apenas o GEb como candidato para a continuação dos estudos visando a sua possível utilização em campo.Aqueous and alcoholic extracts were obtained from crushed dried leaves of tomato plant (Lycopersicon esculentum, Mill. c.v. Cherry. By the use of a methanolic extraction and alkaline precipitation, a product named crude steroidal glycoalkaloid (GEb, was obtained. The presence of tomatidine was characterized in this product. In laboratory, the aqueous and alcoholic extracts and GEb have shown molluscicidal activity against Biomphalaria glabrata (Say, 1818. The crude steroidal glycoalkaloid presented a high molluscicidal activity (LC50 = 8.01 ppm and LC90 = 13.17 ppm, similar to that of tomatine. None of the compounds tested affected B. glabrata egg masses. The level of activity showed by the different extracts and by the GEb, pointed out the GEb as the only candidate able to be considered for further tests toward field trials as molluscicidal agent.

Induction of multiple shoots from leaf segments, in vitro-flowering and fruiting of a dwarf tomato (Lycopersicon esculentum).

Science.gov (United States)

Rao, Kokkirala Venugopal; Kiranmayee, Kasula; Pavan, Umate; Sree, Telakalapalli Jaya; Rao, Alleni V; Sadanandam, Abbagani

2005-08-01

Multiple shoots were induced from leaf explants of Lycopersicon esculentum cultivar MicroTom, within 20-25d, on MS medium supplemented with 8.9 microM benzylaminopurine (BAP)+1.14 microM indole-3-acetic acid (IAA). For rooting, elongated microshoots were excised and transferred onto MS medium supplemented with 4.9 microM indole-3-butyric acid (IBA). Well-developed roots and flower raceme were obtained on d 7 and 13, respectively, upon transfer of the microshoots onto rooting medium. The flowers self-fertilized in vitro and produced mature fruits in additional 15-17d of culture.

EFEITO DE TRICOMAS, ALELOQUÍMICOS E NUTRIENTES NA RESISTÊNCIA DE LYCOPERSICON HIRSUTUM À TRAÇA-DO-TOMATEIRO EFFECT OF TRICHOMES, ALELLOCHEMICALS AND MINERALS ON THE RESISTANCE OF LYCOPERSICON HIRSUTUM TO TOMATO LEAF MINER

Directory of Open Access Journals (Sweden)

GERMANO LEÃO DEMOLIN LEITE

1999-11-01

Full Text Available Estudos foram conduzidos com o objetivo de verificar o efeito de tricomas, aleloquímicos e nutrientes nas folhas de partes do dossel das plantas na resistência de Lycopersicon hirsutum à traça- do-tomateiro, Tuta absoluta (Lepidoptera: Gelechiidae. Foram quantificados os teores de 2-tridecanona (2-TD, 2-undecanona (2-UD, N, P, K, Ca e Mg, densidade e tipos de tricomas e tamanho das folhas nos terços apical, mediano e basal do dossel de plantas de L. hirsutum e de L. esculentum e estudaram- se os efeitos destes fatores sobre características biológicas de T. absoluta. Observou-se elevação no teor de 2-TD da base para o ápice do dossel. Não se detectou diferença significativa quanto ao número de ovos de T. absoluta ao longo do dossel de L. hirsutum, constatando-se em L. esculentum maior oviposição nos terços apical e mediano do que no basal. As folhas do terço apical de L. hirsutum apresentaram maior efeito deletério sobre as larvas de traça.The objective of this work was to study the effect of trichomes, alellochemicals and minerals in the leaves of different canopy heights on the resistance of Lycopersicon hirsutum to tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae. Effects of 2-tridecanone (2-TD, 2-undecanone (2-UD, N, P, K, Ca and Mg levels, density and types of trichomes and leaf area on apical, medium and basal parts of plant dossel of L. hirsutum and L. esculentum on the oviposition and mines number of T. absoluta was studied. Production of 2-TD increased from the bottom to the top of the canopy. The apical part of plants of L. hirsutum showed more antibiotic effect on the caterpillar. T. absoluta oviposited more on leaves of the apical and medium portion of the plants than in the basal parts of L. esculentum.

Changes in plasma membrane aquaporin gene expression under osmotic stress and blue light in tomato

Czech Academy of Sciences Publication Activity Database

Balarynová, Jana; Danihlík, J.; Fellner, Martin

2018-01-01

Roč. 40, č. 2 (2018), č. článku 27. ISSN 0137-5881 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : male-sterile mutant * arabidopsis-thaliana * seed-germination * abscisic-acid * solanum-lycopersicon * nitric-oxide * 7b-1 * protein * hypocotyl * responses * Tomato * Seed * Aquaporins * Blue light * 7B-1 mutant * Mannitol * PIPs Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 1.364, year: 2016

Toxicidade para lagartas de Phthorimaea operculella (Zell. dos aleloquímicos 2-tridecanona e 2-undecanona presentes em tomateiro (Lycopersicon spp. Toxicity of 2-tridecanone and 2-undecanone allelochemicals present in tomato (Lycopersicon spp. for Phthorimaea operculella (Zell. larvae

Directory of Open Access Journals (Sweden)

M.U. Ventura

1995-12-01

Full Text Available Avaliou-se a toxicidade para Phthorimaea operculella (Zell. dos aleloquímicos 2-trídecanona e 2-undecanona, presentes nos exsudatos glandulares dos tricomas de Lycopersicon spp. Determinou-se a toxicidade dos exsudatos de L. hirsutum f. glabratum PI134417 (DL50, do 2-tridecanona (dose letal: DL50 e concentração letal: CL50 e do 2-undecanona (CL50 para lagartas de primeiro ínstar desse inseto. A DL50 foi de 5,54 glândulas e 775,53 ng por lagarta, respectivamente. Em relação à concentração letal, o 2-tridecanona foi mais tóxico do que o 2-undecanona. A toxicidade (CL50 do 2-tridecanona aumentou com a elevação da temperatura de 27 para 32°C e para o 2-undecanona ocorreu o inverso. Concluiu-se que estes compostos podem ter grande importância na resistência do tomateiro para esta praga.This research deals with the toxicity of 2-tridecanone and 2-undecanone allelochemicals, present in the grandular trichomes of Lycopersicon spp., to Phthorimaea operculella (Zell.. The toxicity of the exsudates of L. hirsutum f. glabratum PI 134117 (LD50, of the 2-tridecanone (lethal dose: LD50and lethal concentration: LC50 and 2-undecanone (LC50 to first instar larvae of this pest were determined. The LD50value was 5.54 glands and 775.53 ng per larvae, respectively. With respect to the lethal concentration, the 2-tridecanone was more toxic than the 2-undecanone. The toxicity (CL50 of the 2-tridecanone increased with the elevation of the temperature from 27 to 32°C, but decreased with the 2-undecanone. It was concluded that these compounds can have great importance in the resistance of the tomato plant to this pest.

Effect of physical and chemical mutagens on seed germination and survival of seedling in Lycopersicon esculentum Mill

International Nuclear Information System (INIS)

Jayabalan, N.; Rao, G.R.

1987-01-01

Dry and healthy seeds of Lycopersicon esculentum Mill. var. Co-2 were irradiated with gamma rays at 10 KR, 20 KR, 30 KR, 40 KR and 50 KR. The percentage of seed germination was directly proportional to the dose given. The survival percentage decreased with higher doses. Concentration of EMS and NMU applied, ranged from 10 mM to 50 mM and 1 mM to 5 mM, respectively. The duration of soaking of seed was 4 hours in distilled water and 4 hours in mutagenic agents. In treated seeds, the percentage of germination and survival of seedlings decreased with an increase in concentration of these chemical mutagens. These observations are discussed in detail. (author). 11 refs

Effect of salinity on tomato (Lycopersicon esculentum Mill.) during seed germination stage.

Science.gov (United States)

Singh, Jogendra; Sastry, E V Divakar; Singh, Vijayata

2012-01-01

A study was conducted using ten genetically diverse genotypes along with their 45F1 (generated by diallel mating) under normal and salt stress conditions. Although, tomato (Lycopersicon esculentum Mill.) is moderately sensitive to salinity but more attention to salinity is yet to be required in the production of tomato. In present study, germination rate, speed of germination, dry weight ratio and Na(+)/K(+) ratio in root and shoot, were the parameters assayed on three salinity levels; control, 1.0 % NaCl and 3.0 % NaCl with Hoagland's solution. Increasing salt stress negatively affected growth and development of tomato. When salt concentration increased, germination of tomato seed was reduced and the time needed to complete germination lengthened, root/shoot dry weight ratio was higher and Na(+) content increased but K(+) content decreased. Among the varieties, Sel-7 followed by Arka Vikas and crosses involving them as a parent were found to be the more tolerant genotypes in the present study on the basis of studied parameters.

Effects of recurrent irradiation and cross fertilization on improvement of cultivated tomato (Solanum lycopersicon L.) and wild tomato (Solanum pimpinellifolium L.)

International Nuclear Information System (INIS)

Nunoo, J.

2010-01-01

Two separate experiments were conducted to determine the effects of recurrent irradiation and cross fertilization on the improvement of fruit quality and plant architecture of two tomato species (Solanum lycopersicon L.) and (Solanum pimpinellifolium L.) in Ghana. In the first experiment, a variant line of the wild tomato (Solanum pimpinellifolium L.) (SP 300/30.4.2.4) previously obtained through irradiation with gamma rays at 300 Gy was re-irradiated with gamma rays at 150 Gy and 300 Gy using gamma irradiation. The second experiment involved hybridization of the same variant line (SP 300/30.4.2.4) with five cultivars of the cultivated tomato (Solanum lycopersicon L). Progeny were assessed in both M1 and M2 generations for the first experiment but only at the F 2 generation for the second experiment. Significant variations were observed in number of days to first flowering and 50% fruiting. Fruit size increased from 1.36 g and 1.67 g to 1.77 g and 2.66 g in the M 1 and M 2 generations respectively following re-irradiation at 300 Gy. Three 150 Gy treated plants at the M 1 generation and two 300 Gy treated plants at the M 2 generations exhibited erect growth habit compared to the parental line (SP 300/30.4.2.4) which was sprawling. A variant line among the 300 Gy treated plants had a fused fruit of fruit weight of 3.57 g with four locules. Also, hybridization involving five cultivars of the cultivated tomato (S. lycopersicon L.) as female parents and the variant line (SP 300/30.4.2.4) generated variability in several traits including plant architecture, days to flowering and fruiting, fruit weight and number of seeds per fruit in the F 2 generation. Variations in style-length, number of locules, fruit shape and colour were also observed among the plants in the F 2 generation. Generally, significant improvements were obtained with respect to plant architecture (that is reduced plant height), earliness and fruit quality (that is fruit size and colour). Although no

A ten-week biochemistry lab project studying wild-type and mutant bacterial alkaline phosphatase.

Science.gov (United States)

Witherow, D Scott

2016-11-12

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 techniques, students acquire novel biochemical data in their kinetic analysis of mutant enzymes. The experiments are designed to build on students' work from week to week in a way that requires them to apply quantitative analysis and reasoning skills, reinforcing traditional textbook biochemical concepts. Students are assessed through lab reports focused on journal style writing, quantitative and conceptual question sheets, and traditional exams. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(6):555-564, 2016. © 2016 The International Union of Biochemistry and Molecular Biology.

Morphogenetic Potential of Tomato (Lycopersicon esculentum cv. ‘Arka Ahuti’ to Plant Growth Regulators

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Kanakapura K. NAMITHA

2013-05-01

Full Text Available A highly reproducible in vitro regeneration method for tomato (Lycopersicon esculentum Mill. cultivar ‘Arka Ahuti’ was established by using hypocotyl, leaf and cotyledon explants from in vitro raised seedlings on Murashige and Skoog medium supplemented with different concentrations and combinations of hormones 6-Benzylamino purine (2 to 4 mg/L and Indole-3-acetic acid (0.1 to 1 mg/L. The medium supplemented with 2 mg/L 6-benzylamino purine and 0.1 mg/L indole-3-acetic acid was found to be the best for inducing direct shoot regeneration and multiple shoots per explant from hypocotyl explants. Callus induction was observed in all the explants and regeneration of shoots was also promoted by all these combinations. Shoots were transferred to the elongation medium which also induced 100% rooting. After hardening, plants were transferred to soil. Thus, a tissue culture base line was established for ‘Arka Ahuti’ cultivar of tomato for obtaining direct regeneration using hypocotyl, leaf and cotyledon as explants.

Characterization and evaluation of some lines from cherry tomatoes lycopersicon esculentum mill. Var. Cerasiforme (dunal) and their ability for micropropagation in in vitro conditions

OpenAIRE

Dedejski, George

2012-01-01

Tomato production in the Republic of Macedonia is present on more than 5700 hectares, being the leading vegetable crop in the region of Strumica. Cherry tomato however, is poorly present at our fields, mainly due to the traditional habits of the consumers and the commercial tomato producers to grow tomato varieties with large fruit. Cherry tomato - Lycopersicon esculentum Mill. var. cerasiforme (Dunal) is a tomato variety with small fruit, with different shapes and colors and it is used ma...

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.)

Métodos de remoção da mucilagem e qualidade fisiológica de sementes de tomate (Lycopersicon esculentum, Mill. Methods of mucilage remotion and physiological quality of tomato (Lycopersicon sculentum Mill. seeds

Directory of Open Access Journals (Sweden)

C. Cavariani

1994-04-01

Full Text Available Objetivando estudar diferentes métodos de remoção da mucilagem e a qualidade de sementes de tomate (Lycopersicon esculentum Mill., conduziu-se um experimento, em delineamento inteiramente casualizado com quatro repetições. Após extração manual, sementes e mucilagens foram submetidas aos seguintes tratamentos de remoção: lavagem imediata, fermentação por três dias, ácido clorídrico a 2,5% (25 ml/kg, durante 2 horas, ácido acético a 10% (25 ml/kg de material e hidróxido de amônia a 2,5% (25 ml/kg, durante 2 horas. Seguiu-se a avaliação da qualidade fisiológica das sementes através das determinações de porcentagem de germinação e vigor, pela porcentagem de emergência em areia, condutividade elétrica e pesos das matérias verde e seca de plântulas. Os resultados permitiram concluir que os métodos de remoção por lavagem imediata, fermentação, ácido clorídrico e ácido acético comercial não afetaram a qualidade fisiológica de sementes de tomate; a porcentagem de germinação não foi afetada pelos diferentes métodos de remoção e o método hidróxido de amônia prejudica o vigor das sementes.Different methods of mucilage remotion and quality of tomato (Lycopersicon esculentum Mill. seeds were studied, in a complete randomized design experiment with four replications. After manual extraction, seeds and slimes were submitted to the following remotion treatments: immediate washing, three-day fermentation, hydrochloric acid at 2,5% (25 mg/kg for 2 hrs., acetic acid at 10% (25 ml/kg of material, and ammonia hydroxide at 2,5% (25 ml/kg, for 2 hrs.. A physiological quality evaluation of seeds was carried out through the percentage of germination and vigor, percentage of in-sand emergence, electrical conductivity, and weight of fresh and dry matters of seedlings. The results showed that the methods of immediate washing, fermentation, commercial hydrochloric and acetic acids do not affect the physiological quality of

Data on quantification of signaling pathways activated by KIT and PDGFRA mutants

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Christelle Bahlawane

2016-12-01

Full Text Available The present data are related to the article entitled “Insights into ligand stimulation effects on gastro-intestinal stromal tumors signaling” (C. Bahlawane, M. Schmitz, E. Letellier, K. Arumugam, N. Nicot, P.V. Nazarov, S. Haan, 2016 [1]. Constitutive and ligand-derived signaling pathways mediated by KIT and PDGFRA mutated proteins found in gastrointestinal stromal tumors (GIST were compared. Expression of mutant proteins was induced by doxycycline in an isogenic background (Hek293 cells. Kit was identified by FACS at the cell surface and found to be quickly degraded or internalized upon SCF stimulation for both Kit Wild type and Kit mutant counterparts. Investigation of the main activated pathways in GIST unraveled a new feature specific for oncogenic KIT mutants, namely their ability to be further activated by Kit ligand, the stem cell factor (scf. We were also able to identify the MAPK pathway as the most prominent target for a common inhibition of PDGFRA and KIT oncogenic signaling. Western blotting and micro-array analysis were applied to analyze the capacities of the mutant to induce an effective STATs response. Among all Kit mutants, only Kit Ex11 deletion mutant was able to elicit an effective STATs response whereas all PDGFRA were able to do so.

Somatic hybrid plants between Lycopersicon esculentum and Solanum lycopersicoides.

Science.gov (United States)

Handley, L W; Nickels, R L; Cameron, M W; Moore, P P; Sink, K C

1986-02-01

Leaf mesophyll protoplasts of Lycopersicon esculentum (2n=2x=24) were fused with suspension culture-derived protoplasts of Solanum lycopersicoides (2n=2x=24) and intergeneric somatic hybrid plants were regenerated following selective conditions. A two phase selection system was based on the inability of S. lycopersicoides protoplasts to divide in culture in modified medium 8E and the partial inhibition of L. esculentum protoplasts by the PEG/DMSO fusion solution. At the p-calli stage, putative hybrids were visually selected based on their hybrid vigor and lime-green coloration in contrast to slower growing parental calli characterized by a watery, whitish-brown coloration. Early identification of the eight hybrid plants studied was facilitated by isozyme analysis of leaf tissue samples taken from plants in vitro at the rooting stage. Regenerated plants growing in planting medium were further verified for hybridity by 5 isozymes marking 7 loci on 5 chromosomes in tomato. These included Skdh-1 mapped to chromosome 1 of tomato, Pgm-2 on chromosome 4, Got-2 and Got-3 on chromosome 7, Got-4 on chromosome 8, and Pgi-1 and Pgdh-2 both on chromosome 12. Fraction I protein small subunits further confirmed the hybrid nature of the plants with bands of both parents expressed in all hybrids. The parental chloroplasts could not be differentiated by the isoelectric points of the large subunit. Seven of the eight somatic hybrids had a chromosome number ranging from the expected 2n=4x=48 to 2n=68. Mixoploid root-tip cells containing 48, 53, 54 or 55 chromosomes for two of the hybrids were also observed.

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

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

INTENSIDAD DE LOS SABORES BÁSICOS DEL TOMATE (Lycopersicon esculentum EN SEIS ESTADOS DE MADUREZ INTENSITY OF BASIC TASTES OF TOMATO (Lycopersicon esculentum IN SIX MATURITY STAGES

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KATHERIN CASTRO

2009-06-01

Full Text Available El tomate (Lycopersicon esculentum, la hortaliza más sembrada en Colombia, es considerada una de las más importantes por su volumen de producción y demanda. La exigencia del consumidor en sus características organolépticas hace necesario un estudio detallado acerca de sus propiedades fisicoquímicas y sensoriales. El análisis sensorial se realizó con un panel entrenado de cinco jueces y las muestras de tomate fueron escogidas de acuerdo con parámetros físicos de color (Cuadro 1 y calidad en los seis estados de madurez del fruto. Se empleó el método de perfil descriptivo, con una escala de respuesta de 0 a 10 puntos, con el fin de cuantificar la intensidad de los sabores básicos (dulce, ácido, amargo, salado y umami. Se realizó un diseño aleatorizado en bloques con seis réplicas por cada tratamiento y un nivel de significancia del 5%. Este indicó la inexistencia de diferencias significativas en las intensidades para cada estado de madurez (p≤ 0,05, y la existencia de diferencias significativas en las intensidades para cada sabor básico evaluado (p>0,05. Mediante el perfil sensorial, se logró establecer que en los estados de madurez 1 y 2, el atributo de mayor intensidad fue el ácido, en los estados de madurez 3, 4 y 5, el atributo que sobresalió fue el dulce y en el estado 6, el atributo percibido en mayor grado fue el umami. Los sabores amargo y salado, se percibieron en una baja intensidad, en los diferentes estados de madurez.The tomato (Lycopersicon esculentum, the vegetable more seeding in the country, is considered one of most important by its volume of production and demand. The exigency of the consumer in sensory characteristics makes necessary a detailed study about its physicochemistry and sensory properties. The sensory analysis was made with a trained panel of five judges and the tomato samples were chosen according to parameters of color and quality in the six ripeness stages of the fruit. Was made using the

UV irradiation as a tool for obtaining asymmetric somatic hybrids between Nicotiana plumbaginifolia and Lycopersicon esculentum

International Nuclear Information System (INIS)

Vlahova, M.; Hinnisdaels, S.; Frulleux, F.; Claeys, M.; Atanassov, A.; Jacobs, M.

1997-01-01

UV-irradiated kanamycin-resistant Lycopersicon esculentum leaf protoplasts were fused with wild-type Nicotiana plumbaginifolia leaf protoplasts. Hybrid calli were recovered after selection in kanamycin-containing medium and subsequently regenerated. Cytological analysis of these regenerants showed that several (2–4) tomato chromosomes, or chromosome fragments, were present in addition to a polyploid Nicotiana genome complement. All lines tested had neomycin phosphotransferase (NPTII) activity and the presence of the kanamycin gene was shown by Southern blotting. In two cases a different hybridization profile for the kanamycin gene, compared to the tomato donor partner, was observed, suggesting the occurence of intergenomic recombination events. The hybrid nature of the regenerants was further confirmed by Southernblotting experiments using either a ribosomal DNA sequence or a tomato-specific repeat as probes. The hybrids were partially fertile and some progeny could be obtained. Our results demonstrate that UV irradiation is a valuable alternative for asymmetric cell-hybridization experiments. (author)

The chloroplasts membrane phospholipids of Chlamydomonas reinhardii mutant not forming the Photosystem 2

International Nuclear Information System (INIS)

Trusova, V.M.; Ladygin, V.G.; Mezentsev, V.V.; Molchanov, M.I.

1987-01-01

Study on a component composition and physical state of photosynthetic membranes of Chlamydomonas chloroplasts of the wild type and mutant A-110 with disturbance of electron transfer chain in the photosystem 2 region permitted to conclude that 170 A diameter particles localized on the internal hydrophobic surface of membrane chips are deleted with respect to phosphatidylglycerin. The results obtained permit to suggest that the formation of protein-lipid complexes containing phosphatidylglycerins is suppressed in mutant A-110 which is not capable of the lamellar system differentation in

Effect of Heat Shock Treatment and Aloe Vera Coating to Chilling Injury Symptom in Tomato (Lycopersicon asculantum Mill.

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Sutrisno

2012-04-01

Full Text Available This research was undertaken to determine the effect of length in heat shock and edible coating as pre-storage treatment to Chilling Injury (CI symptom reflected by ion leakage induced and quality properties in tomato (Lycopersicon asculantum Mill.. Heat Shock Treatment (HST was conducted at three different levels of length, which were, 20; 40 and 60 min. Edible coating was conducted using aloe vera gel. The result showed that HST and Aloe Vera Coating (AVC were more effective to reduce CI symptom at lower chilling storage. Prolong exposure to heated water may delay climacteric peak. The length of heat shock, AVC treatment and low temperature storage significantly affected the tomato quality parameter but not significantly different for each treatment except weight loss. HST for 20 min at ambient temperature was significantly different to other treatment.

Long-lived mitochondrial (Mit) mutants of Caenorhabditis elegans utilize a novel metabolism.

Science.gov (United States)

Butler, Jeffrey A; Ventura, Natascia; Johnson, Thomas E; Rea, Shane L

2010-12-01

The Caenorhabditis elegans mitochondrial (Mit) mutants have disrupted mitochondrial electron transport chain (ETC) functionality, yet, surprisingly, they are long lived. We have previously proposed that Mit mutants supplement their energy needs by exploiting alternate energy production pathways normally used by wild-type animals only when exposed to hypoxic conditions. We have also proposed that longevity in the Mit mutants arises as a property of their new metabolic state. If longevity does arise as a function of metabolic state, we would expect to find a common metabolic signature among these animals. To test these predictions, we established a novel approach monitoring the C. elegans exometabolism as a surrogate marker for internal metabolic events. Using HPLC-ultraviolet-based metabolomics and multivariate analyses, we show that long-lived clk-1(qm30) and isp-1(qm150) Mit mutants have a common metabolic profile that is distinct from that of aerobically cultured wild-type animals and, unexpectedly, wild-type animals cultured under severe oxygen deprivation. Moreover, we show that 2 short-lived mitochondrial ETC mutants, mev-1(kn1) and ucr-2.3(pk732), also share a common metabolic signature that is unique. We show that removal of soluble fumarate reductase unexpectedly increases health span in several genetically defined Mit mutants, identifying at least 1 alternate energy production pathway, malate dismutation, that is operative in these animals. Our study suggests long-lived, genetically specified Mit mutants employ a novel metabolism and that life span may well arise as a function of metabolic state.

Comparison of regeneration potentials in tissue cultures of primitive and cultivated tomato species (Lycopersicon sp.

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M. Lech

2014-01-01

Full Text Available Regeneration capacities of two tomato cultivars: Potentat and Rutgers, and of three accessions of wild tomato species: Lycopersicon peruvianum PI 128650, L. peruvianum var. dentatum PI 128655 and L. glandulosum were studied using an universal medium suitable for regeneration of those plants from leaf pieces in tissue culture. Fragments of leaf blades were taken from plants raised in greenhouse conditions and placed on a modified MS medium containing 0.3 mg/l IAA and 3.0 mg/l BAP solidified with 1% agar. The explants were transferred every 4-5 weeks on fresh medium of the same composition. It was shown that all the three primitive tomato species revealed much higher multiplication coefficients than the two cultivars. Appropriate values were: 11 - for L. glandulosum, 8 - for L. peruvianum, 7 - for L. peruvianum var. dentatum, 4 - for L. esculentum cv. Potentat and 2 - cv. Rutgers. Completely regenerated plants were obtained from all the tested species, but organogenesis occurred almost two weeks earlier in wild tomatoes than in the culitivated varieties of L. esculentum.

Furfural and hydroxymethylfurfural tolerance in Escherichia coli ΔacrR regulatory mutants.

Science.gov (United States)

Luhe, Annette Lin; Lim, Chan Yuen; Gerken, Henri; Wu, Jinchuan; Zhao, Hua

2015-01-01

The presence of the highly toxic furfural and hydroxymethylfurfural (HMF) in the hydrolysate of lignocellulosic biomass prompted the investigation of the Escherichia coli ΔacrR regulatory mutant for higher tolerance to these compounds, to facilitate the production of biofuels and biochemicals, and further biocatalytic conversions. In comparison with the parental strain, the regulatory mutant with the upregulated efflux pump AcrAB-TolC produced moderately better growth and higher tolerance to concentrations of furfural and HMF between 1 and 2 g L(-1) . © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Phytochemical and nutrient/antinutrient interactions in cherry tomato (Lycopersicon esculentum) fruits.

Science.gov (United States)

Oyetayo, Folake Lucy; Ibitoye, Muyiwa Femi

2012-07-01

The fruit of the cherry tomato (Lycopersicon esculentum (Solanaceae)) was analysed for mineral and antinutrient composition. Phosphorus (33.04 ± 0.21 mg/100g) was the most abundant mineral in the fruit, followed by calcium (32.04 ± 0.06 mg/100 g), and potassium (11.9 ± 0.1 mg/100 g) and manganese (9.55 ± 0.28 mg/100 g) were also present in appreciable quantities. Antinutrients, including phytate, glycoside, saponin and tannin, were screened and quantified. Phytate (112.82 ± 0.1 mg/100 g), glycoside (2.33 ± 0.00 mg/100 g), saponin (1.31 ± 0.00 mg/100g) and tannin (0.21 ± 0.00 mg/100 g) were present in the fruit but phlobatanin and glycosides with steroidal rings were not found. The calculated calcium:phytate ratio of the fruits was below the critical value and the calculated [calcium] [phytate]:[zinc] molar ratio was less than the critical value. The calcium:phosphorus ratio (0.97 mg/100 g) shows the fruit to be a good source of food nutrients, while the sodium:potassium value was less than 1. Ca/P ratio below 0.5 indicates deficiency of these minerals while Na/K ratio above 1 is detrimental because of excessive sodium levels. The results of the study generally revealed the fruit to be rich in minerals but containing insufficient quantities of antinutrients to result in poor mineral bioavailability.

Nitrogen management in tomato (Lycopersicon esculentum) using 15N-enriched fertilizer

International Nuclear Information System (INIS)

Shivananda, T.N.; Iyengar, B.R.V.; Kotur, S.C.

1996-01-01

An experiment was conducted during 1991 to study nitrogen management using 15 N-enriched fertilizer, to achieve economy in fertilizer N input by reduction and postponement of the basal dose in Arka Vikas tomato (Lycopersicon esculentum Miller nom. cons). Application of 90 kg N/ha in 3 equal splits at 10, 30 and 50 days after transplanting did not show any reduction in total N uptake, dry-matter and fruit yields compared with 120 kg N/ha applied in 3 splits (60 kg N/ha basal and 30 kg top-dressed 20 and 40 days after transplanting). Band application of the basal dose and top-dressing at 20 days after transplanting resulted in higher N derived from fertilizer (Ndff), its uptake and utilization. Top-dressing of 30 or 40 kg N/ha at 10 days after transplanting resulted in better utilization than broadcasting the basal dose of 60 kg N/ha. Application at 40-50 days after transplanting showed poor uptake and utilization of applied N. The succeeding Arka Kalyan onion (Allium cepa L.) utilized 2.95-6.37% residual N, the highest being from the split application at 40 days after transplanting. Thus there was economy in fertilizer N input and higher carry-over of residual N for determinate cultivar of tomato be delaying as well as reducing the basal dose and confining the top-dressing to 30 days after transplanting. (author)

Nicotine promotes rooting in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

Science.gov (United States)

Bamel, Kiran; Gupta, Rajendra; Gupta, Shrish C

2015-11-01

Nicotine promotes rooting in leaf explants of tomato (Lycopersicon esculentum Miller var. Pusa Ruby). Nicotine at 10(-9) to 10(-3) M concentrations was added to the MS basal medium. The optimum response (three-fold increase in rooting) was obtained at 10(-7) M nicotine-enriched MS medium. At the same level i.e. 10(-7) M Nicotine induced dramatic increase (11-fold) in the number of secondary roots per root. We have shown earlier that exogenous acetylcholine induces a similar response in tomato leaves. Since nicotine is an agonist of one of the two acetylcholine receptors in animals, its ability to simulate ACh action in a plant system suggests the presence of the same molecular mechanism operative in both, animal and plant cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Hygienic quality of traditional processing and stability of tomato (Lycopersicon esculentum) puree in Togo.

Science.gov (United States)

Ameyapoh, Yaovi; de Souza, Comlan; Traore, Alfred S

2008-09-01

Microbiological and physicochemical qualities of a tomato (Lycopersicon esculentum) puree production line (ripe tomato, washing, cutting, pounding, bleaching, straining, bottling and pasteurization) and its preservation in Togo, West Africa, were studied using the HACCP method. Samples generated during the steps described previously were analyzed by determining sensory, chemical and microbiological characteristics. Samples were analyzed using MPN for coliform populations and plate count methodology for other bacteria. The microorganisms involved in spoilage of the opened products were moulds of genera Penicillium, Aspergillus, Fusarium, Geotrichum, Mucor and gram-positive Bacillus bacteria. The preserved tomato puree exhibited a pH value of 4.3, 90% water content, 0.98 water activity (aw) and an average ascorbic acid level of 27.3mg/100g. Results showed that the critical control point (CCP) of this tomato puree processing line is the pasteurization stage. The analysis of selected microbiological and physicochemical parameters during the preservation of bottled tomato puree indicated that this product was stable over 22 months at 29 degrees C. But the stability of the opened product stored at 29 degrees C did not exceed two months.

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

Allergenicity assessment of genetically modified cucumber mosaic virus (CMV) resistant tomato (Solanum lycopersicon).

Science.gov (United States)

Lin, Chih-Hui; Sheu, Fuu; Lin, Hsin-Tang; Pan, Tzu-Ming

2010-02-24

Cucumber mosaic virus (CMV) has been identified as the causal agent of several disease epidemics in most countries of the world. Insect-mediated virus diseases, such as those caused by CMV, caused remarkable loss of tomato (Solanum lycopersicon) production in Taiwan. With expression of the CMV coat protein gene (Cmvcp) in a local popular tomato cultivar L4783, transgenic tomato line R8 has showed consistent CMV resistance through T(0) to T(8). In this report, the allergenicity of the CMV coat protein (CMV cp) expressed in transgenic tomato R8 was assessed by investigation of the expression of the transgene source of protein, sequence similarity with known allergens, and resistance to pepsin hydrolysis. There is no known account for either the CMV or its coat protein being an allergen. The result of a bioinformatic search also showed no significant homology between CMV cp and any known allergen. The pepsin-susceptible property of recombinant CMV cp was revealed by a simulated gastric fluid (SGF) assay. Following the most recent FAO/WHO decision tree, all results have indicated that CMV cp was a protein with low possibility to be an allergen and the transgenic tomato R8 should be considered as safe as its host.

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

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.

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

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)

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)

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.)

Isolation and characterisation of a dwarf rice mutant exhibiting defective gibberellins biosynthesis.

Science.gov (United States)

Ji, S H; Gururani, M A; Lee, J W; Ahn, B-O; Chun, S-C

2014-03-01

We have isolated a severe dwarf mutant derived from a Ds (Dissociation) insertion mutant rice (Oryza sativa var. japonica c.v. Dongjin). This severe dwarf phenotype, has short and dark green leaves, reduced shoot growth early in the seedling stage, and later severe dwarfism with failure to initiate flowering. When treated with bioactive GA3 , mutants are restored to the normal wild-type phenotype. Reverse transcription PCR analyses of 22 candidate genes related to the gibberellin (GA) biosynthesis pathway revealed that among 22 candidate genes tested, a dwarf mutant transcript was not expressed only in one OsKS2 gene. Genetic analysis revealed that the severe dwarf phenotype was controlled by recessive mutation of a single nuclear gene. The putative OsKS2 gene was a chromosome 4-located ent-kaurene synthase (KS), encoding the enzyme that catalyses an early step of the GA biosynthesis pathway. Sequence analysis revealed that osks2 carried a 1-bp deletion in the ORF region of OsKS2, which led to a loss-of-function mutation. The expression pattern of OsKS2 in wild-type cv Dongjin, showed that it is expressed in all organs, most prominently in the stem and floral organs. Morphological characteristics of the dwarf mutant showed dramatic modifications in internal structure and external morphology. We propose that dwarfism in this mutant is caused by a point mutation in OsKS2, which plays a significant role in growth and development of higher plants. Further investigation on OsKS2 and other OsKS-like proteins is underway and may yield better understanding of the putative role of OsKS in severe dwarf mutants. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Investigation of the effects of aluminum stress on some macro and micro-nutrient contents of the seedlings of lycopersicon esculentum mill. by using scanning electron microscope

International Nuclear Information System (INIS)

Colak, G.; Catak, E.; Baykul, M.C.

2014-01-01

This study was planned to see the affect of aluminum stress on plant nutrition and metabolism. The effects of aluminum stress on uptake level of some macro- and micro-nutrients from the nutrition solution into the seedlings of Lycopersicon esculentum Mill. and on mobilization of some nutrient elements in the seedlings were examined at the level of epidermal cells. The elemental structure of root, hypocotyl and cotyledon epidermal cells were determined by Energy Dispersive Xray Microanalysis (EDX) performed in a local area 50 nm in diameter at the level of a single epidermal cell cytoplasm by using low vacuum (24 pascal ) Scanning Electron Microscope. EDX analysis revealed that aluminum content of the cells was increasing with the increased concentrations of aluminum in the nutrient solution and that aluminum largelyaccumulated in the roots. Aluminum concentration was much higher in the root epidermal cells of the seedlings incubated in aluminum containing media for 17 days without adding any nutrient solution; it was also true for the local EDX analysis of radicle epidermal cells from the same series. Aluminum stress was found to tend to modify the plant nutritional element content of the cells and this was particularly of critical importance in terms of some macro- and micro-nutrients. The assessments performed at the level of epidermal cells of young seedlings of Lycopersicon esculentum suggest that aluminum stress leads to an absolute change in the plant nutritional element composition of the cells and in the mobilization of some nutritional elements in the seedlings. (author)

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)

Simultaneous ozone fumigation and fluoranthene sprayed as mists negatively affected cherry tomato (Lycopersicon esculentum Mill).

Science.gov (United States)

Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

2010-07-01

Ozone (O(3)) fumigated at 120 microg L(-1) for 12 hd(-1) was combined with 10 microM fluoranthene, and other treatments, including Mannitol solution to investigate the interaction of the two pollutants on tomato plant (Lycopersicon esculentum Mill). Using ten treatments including Mannitol solution and a control, exposure experiment was conducted for 34 d inside six growth chambers used for monitoring the resulted ecophysiological changes. Visible foliar injury, chlorophyll a fluorescence, leaf pigment contents, CO(2) uptake and water vapor exchange were monitored in tomato. Ozone or fluoranthene independently affected some ecophysiological traits of the tomato. In addition, simultaneous treatments with the duo had increased (additive) negative effects on the photosynthesis rate (A(max)), stomatal conductance (g(s)), chlorophyll pigment contents (Chl a, Chl b and Chl((a+b))) and visible foliar symptoms. Contrarily, alleviation of the negative effects of O(3) on the leaf chlorophyll a fluorescence variables by fluoranthene occurred. Mannitol solution, which functioned as a reactive oxygen species scavenger was able to mitigate some negative effects of the two pollutants on the tomato plants. Copyright (c) 2010 Elsevier Inc. All rights reserved.

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.)

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

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

BRED: a simple and powerful tool for constructing mutant and recombinant bacteriophage genomes.

Directory of Open Access Journals (Sweden)

Laura J Marinelli

Full Text Available Advances in DNA sequencing technology have facilitated the determination of hundreds of complete genome sequences both for bacteria and their bacteriophages. Some of these bacteria have well-developed and facile genetic systems for constructing mutants to determine gene function, and recombineering is a particularly effective tool. However, generally applicable methods for constructing defined mutants of bacteriophages are poorly developed, in part because of the inability to use selectable markers such as drug resistance genes during viral lytic growth. Here we describe a method for simple and effective directed mutagenesis of bacteriophage genomes using Bacteriophage Recombineering of Electroporated DNA (BRED, in which a highly efficient recombineering system is utilized directly on electroporated phage DNA; no selection is required and mutants can be readily detected by PCR. We describe the use of BRED to construct unmarked gene deletions, in-frame internal deletions, base substitutions, precise gene replacements, and the addition of gene tags.

Characterization of endophytic Bacillus strains from tomato plants (Lycopersicon esculentum) displaying antifungal activity against Botrytis cinerea Pers.

Science.gov (United States)

Kefi, Asma; Ben Slimene, Imen; Karkouch, Ines; Rihouey, Christophe; Azaeiz, Sana; Bejaoui, Marwa; Belaid, Rania; Cosette, Pascal; Jouenne, Thierry; Limam, Ferid

2015-12-01

Eighty endophytic bacteria were isolated from healthy tissues of roots, stems, leaves and fruits of tomato plants (Lycopersicon esculentum). Four strains, named BL1, BT5, BR8 and BF11 were selected for their antagonism against Botrytis cinerea, a phytopathogenic fungus responsible of gray mold in several important crops, with growth inhibitory activity ranging from 27 to 53%. Morphological, biochemical, and molecular parameters as 16S rDNA sequencing demonstrated that the selected bacterial strains were related to Bacillus species which are known to produce and secrete a lot of lipopeptides with strong inhibitory effect against pathogen mycelial growth. Electrospray mass spectrometry analysis showed that these strains produced heterogeneous mixture of antibiotics belonging to fengycin and surfactin for BL1 and BT5, to iturin and surfactin for BR8, to bacillomycin D, fengycin and surfactin for BF11. Furthermore, these bacteria exhibited biocontrol potential by reducing the disease severity when tested on detached leaflets. Based on their antifungal activity against Botrytis cinerea, these strains could be used for biological control of plant diseases.

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)

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)

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)

Uptake, localization, and speciation of cobalt in Triticum aestivum L. (wheat) and Lycopersicon esculentum M. (tomato).

Science.gov (United States)

Collins, Richard N; Bakkaus, Estelle; Carrière, Marie; Khodja, Hicham; Proux, Olivier; Morel, Jean-Louis; Gouget, Barbara

2010-04-15

The root-to-shoot transfer, localization, and chemical speciation of Co were investigated in a monocotyledon (Triticum aestivum L., wheat) and a dicotyledon (Lycopersicon esculentum M., tomato) plant species grown in nutrient solution at low (5 muM) and high (20 muM) Co(II) concentrations. Cobalt was measured in the roots and shoots by inductively coupled plasma-mass spectrometry. X-ray absorption spectroscopy measurements were used to identify the chemical structure of Co within the plants and Co distribution in the leaves was determined by micro-PIXE (particle induced X-ray emission). Although the root-to-shoot transport was higher for tomato plants exposed to excess Co, both plants appeared as excluders. The oxidation state of Co(II) was not transformed by either plant in the roots or shoots and Co appeared to be present as Co(II) in a complex with carboxylate containing organic acids. Cobalt was also essentially located in the vascular system of both plant species indicating that neither responded to Co toxicity via sequestration in epidermal or trichome tissues as has been observed for other metals in metal hyperaccumulating plants.

Internalization and down-regulation of the human epidermal growth factor receptor are regulated by the carboxyl-terminal tyrosines

DEFF Research Database (Denmark)

Helin, K; Beguinot, L

1991-01-01

with receptors in which 1, 2, or all 3 tyrosines were changed to phenylalanines. The triple point mutant EGF-R, expressed in NIH-3T3, exhibited low autophosphorylation in vivo, low biological and reduced kinase activities. Single and double point mutants were down-regulated, as well as wild type EGF......-R in response to EGF showing a half-life of about 1 h. Degradation of the triple point mutant, however, was impaired and resulted in a half-life of 4 h in the presence of EGF. EGF-dependent down-regulation of surface receptors was decreased in the triple point mutant EGF-R as was internalization and degradation...... of EGF. The specific rate of internalization of the triple point mutant was reduced. By contrast, intracellular processing of ligand previously internalized at 20 degrees C was similar between wild type and mutant receptors. Taken together the data indicate that the delay in degradation observed in cells...

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…

Season-controlled changes in biochemical constituents and oxidase enzyme activities in tomato (Lycopersicon esculentum Mill.).

Science.gov (United States)

Sen, Supatra; Mukherji, S

2009-07-01

Season-controlled changes in biochemical constituents viz. carotenoids (carotene and xanthophyll) and pectic substances along with IAA-oxidase and polyphenol oxidase (PPO) enzyme activities were estimated/assayed in leaves of Lycopersicon esculentum Mill. (tomato) in two developmental stages--pre-flowering (35 days after sowing) and post-flowering (75 days after sowing) in three different seasons--summer rainy and winter Carotenoid content along with pectic substances were highest in winter and declined significantly in summer followed by rainy i.e. winter > summer > rainy. Carotenoid content was significantly higher in the pre-flowering as compared to post-flowering in all three seasons while pectic substances increased in the post-flowering as compared to pre-flowering throughout the annual cycle. IAA oxidase and PPO enzyme activities were enhanced in rainy and decreased sharply in summer and winter i.e. rainy > summer > winter. Both the enzymes exhibited higher activity in the post-flowering stage as compared to pre-flowering in all three seasons. These results indicate winter to be the most favourable season for tomato plants while rainy season environmental conditions prove to be unfavourable (stressful) with diminished content of carotenoid and pectic substances and low activities of IAA oxidase and PPO, ultimately leading to poor growth and productivity.

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)

Cultivo de embriões de tomate in vitro visando a introgressão de genes de Lycopersicon peruvianum em L. esculentum Tomato embryo culture for introgression of genes of Lycopersicon peruvianum in L. esculentum

Directory of Open Access Journals (Sweden)

Fernando A. S. Aragão

2002-12-01

Full Text Available Estudou-se diferentes protocolos de germinação e manutenção de híbridos interespecíficos (Lycopersicon esculentum X L. peruvianum pela melhoria das condições de cultura in vitro bem como da aclimatação das plantas germinadas. Quanto à regeneração dos embriões, três formulações de meios de cultura para resgate de embrião foram avaliadas, em combinação com distintos períodos de tempo. A recuperação de híbridos interespecíficos foi influenciada pelo meio de cultura utilizado para o plaqueamento das sementes e pelo intervalo entre a polinização artificial e o plaqueamento. O meio HLH proporcionou os melhores resultados. O intervalo entre 25 e 35 dias após a polinização foi determinado como sendo o período ideal para recuperação. Para aclimatização, foram avaliadas plantas de L. esculentum, L. peruvianum, híbridos interespecíficos (F1 e das gerações RC1 e RC2. O processo de aclimatização foi influenciado pelo tamanho das gemas utilizadas na repicagem anterior à aclimatização, pelos materiais genéticos utilizados e pelo tempo de manutencão das plântulas em tubo de ensaio. A geracão F1 apresentou a melhor capacidade de aclimatização. O período ideal para aclimatização variou entre 26 e 35 dias após a repicagem em tubo de ensaio. As aclimatizações realizadas sob condições ambientais amenas, alcançaram êxito total quanto à sobrevivência das plântulas.Three culture media in combination with distinct accessions, crossing generations and periods of time after artificial pollination were evaluated in order to identify more efficient protocols to recover interspecific hybrids between Lycopersicon esculentum and L. peruvianum. Both type of media for seed plating and the interval time for fruit harvest after artificial pollination had significant influence on the recovery of interspecific hybrids. The HLH medium gave the best results. The interval between 25 and 35 days after the artificial

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.

Weed control in tomato (lycopersicon esculentum mill.) through mulching and herbicides

International Nuclear Information System (INIS)

Bakht, T.; Khan, I.A.

2014-01-01

Experiments were conducted at the Agricultural Research Farm of the University of Agriculture, Peshawar during 2012 and 2013 to determine the impact of row spacing and weed management strategies on tomato (Lycopersicon esculantum Mill.). Variety 'Roma' was planted on a plot size of 4.8m x 3m using a randomized complete block (RCB) design in split plot arrangements, having four replications. The experiment comprised of row spacing in main plots and ten treatments in the subplots that included five mulches viz., white polyethylene, black polyethylene, wheat straw, newspaper and saw dust; three herbicide treatments i.e. fenoxaprop-p-ethyl, pendimethalin, s-metolachlor along with a hand weeding treatment and a weedy check. The data were recorded on weed density m-2 at 20 days after treatments, plant height, fruit yield (kg ha-1). All the studied parameters were significantly affected by the row spacing (factor A) and weed management treatments (factor B); however, the interaction effects were non-significant. An increase in weed density was observed with increase in row spacing, having weed density of 3.39, 4.19 and 4.53 weeds m-2 for 40, 60 and 80 row spacing, respectively. The overall weed density m-2 ranged between 3.24 to 4.30 m-2. A maximum plant height of 62.44cm was recorded in weedy check and minimum 53.31cm plant height was observed in hand weeding treatments. As regards the fruit yield, a highest yield of 2.51 t ha-1 was recorded at row spacing of 60 cm (factor A) and the application of poly ethylene black plastic resulted in significantly highest fruit yield (4.04 t ha-1) among factor B treatments. (author)

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.

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)

Accumulation of New Polypeptides in Ri T-DNA-Transformed Roots of Tomato (Lycopersicon esculentum) during the Development of Vesicular-Arbuscular Mycorrhizae.

Science.gov (United States)

Simoneau, P; Louisy-Louis, N; Plenchette, C; Strullu, D G

1994-06-01

Root-inducing transferred-DNA (Ri T-DNA)-transformed roots of tomato (Lycopersicon esculentum) were in vitro inoculated with surface-sterilized vesicular-arbuscular mycorrhizal leek root pieces. About 1 week after inoculation, the infection of the transformed root culture by the fungal endophyte was confirmed by photonic microscopy. Total proteins were extracted from the mycorrhizal roots and analyzed by two-dimensional polyacrylamide gel electrophoresis. Control gels were run with proteins extracted from noninoculated roots mixed with purified intraradical vesicles and extraradical hyphae. Comparison of the resulting patterns revealed the presence of two polypeptides with estimated apparent masses of 24 and 39 kDa that were detected only in infected roots. Polypeptides with similar migration parameters were not detected in roots challenged with spore extracts, suggesting that the accumulation of the polypeptides was directly linked to root colonization by the fungus rather than to induction by fungus-derived elicitors.

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

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

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)

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases

OpenAIRE

Adnan, Humaira; Zhang, Zhenbo; Park, Hyun-Joo; Tailor, Chetankumar; Che, Clare; Kamani, Mustafa; Spitalny, George; Binnington, Beth; Lingwood, Clifford

2016-01-01

Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subu...

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)

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.)

Identificação de genótipos do gênero Solanum (secção Lycopersicon com resistência a Stemphylium solani e S. lycopersici Identification of Solanum (section Lycopersicon accessions with resistance to Stemphylium solani and S. lycopersici

Directory of Open Access Journals (Sweden)

Bruno Eduardo C de Miranda

2010-06-01

Full Text Available A mancha-de-estenfílio do tomateiro, causada pelos fungos Stemphylium solani e S. lycopersici, foi considerada, por muito tempo, como uma doença secundária devido à utilização combinada de fungicidas e variedades resistentes. Recentemente, severas epidemias da mancha-de-estenfilio têm sido relatadas nas várias regiões produtoras sugerindo a necessidade de retomar o emprego de cultivares com resistência a esta enfermidade. O objetivo do presente trabalho foi avaliar a reação de genótipos cultivados e silvestres de tomateiro [Solanum (secção Lycopersicon] frente a isolados destas duas espécies de Stemphylium. Na primeira etapa do trabalho, 109 genótipos de Solanum (secção Lycopersicon foram avaliados via inoculação com uma suspensão de 10(4 conídios/mL dos isolados 'EH-1740' (S. solani e 'EH-1749' (S. lycopersici. As plantas foram transplantadas aos 18 dias da semeadura e inoculadas sete dias depois. A avaliação da resposta dos genótipos foi feita 15 dias após a inoculação. Cinqüenta e oito genótipos considerados promissores foram novamente avaliados (com os mesmos isolados em um segundo experimento. Neste experimento a reação dos genótipos foi avaliada cada dois dias utilizando como critérios o período de incubação e a severidade da doença através de uma escala de notas de 0 a 5. Com os valores de severidade, nas diferentes leituras, foi calculada a área abaixo da curva de progresso da doença e o índice de doença. Foram identificadas 35 fontes de resistência às duas espécies de Stemphylium em genótipos das espécies S. lycopersicum, S. habrochaites, S. peruvianum e S. pimpinellifolium. Os genótipos de S. lycopersicum e S. pimpinellifolium resistentes possuem, provavelmente, o gene de resistência Sm. No entanto, os genótipos de S. peruvianum e S. habrochaites podem representar fontes de novos genes/alelos que conferem resistência às duas espécies fúngicas. Esta potencial diversidade de fatores

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)

Antioxidant-enzyme reaction to the oxidative stress due to alpha-cypermethrin, chlorpyriphos, and pirimicarb in tomato (Lycopersicon esculentum Mill.).

Science.gov (United States)

Chahid, Karim; Laglaoui, Amin; Zantar, Said; Ennabili, Abdeslam

2015-11-01

Tomato (Lycopersicon esculentum Mill.) becomes one of the world's foremost vegetables, and its world production and consumption have increased fairly quickly. The capacity to induce oxidative stress in tomato plant, exposed to three xenobiotics such as alpha-cypermethrin, chlorpyriphos, and pirimicarb, was investigated by the evaluation of lipid peroxidation by measuring malondialdehyde (MDA) rate; also, we studied the response of tomato to this stress by assessing the response of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione-s-transferase (GST), and glutathione reductase (GR). The effect of the insecticides was observed using four concentrations (25, 50, 75, and 100%) for germinating seeds and only the recommended concentration in agriculture (100%) for growing plants. Our results show an important accumulation of MDA, demonstrating the increase of lipid peroxidation in consequence of the excessive reactive oxygen species (ROS) production due to insecticide treatment. In response to this oxidative stress in tomato seedlings and plants, the activities of antioxidant-enzyme system were generally enhanced. The electrophoretic analysis showed also the apparition of new isoenzymes as the case for CAT and POD.

Selection of tomato mutants (lycopersicon esculentum mill) under conditions of drought stress

International Nuclear Information System (INIS)

Gonzalez, Maria Caridad; Mansoor, Ali; Suarez, Lorenzo; Mukandama, Jean P.; Rodriguez, Yanet

2001-01-01

At the National Institute of Agricultural Sciences were evaluated under conditions of drought estres an M5 population obtained starting from the irradiation of seeds of the Amalia and INCA 9-1varieties with dose of 300 and 500 Gy of rays gamma of 60 Co. The number of clusters for plant, mass average of the fruits, number of fruits for plant and yield for plant, the content of total soluble solids and the acidity of the fruits was evaluated observing differ highly significant among the different ones lines and the respective donating studied. Promissory genotipos of high productive potential was selected under this condition

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)

Factors affecting the production of seeds in fully fertile tomatoes (Lycopersicon esculentum L. Mill. and those showing a tendency to parthenocarpy

Directory of Open Access Journals (Sweden)

Barbara Gabara

2014-01-01

Full Text Available Comparative studies on the development of the female gametophyte, pollination and fertilization in two lines of Lycopersicon esculentum, Kholodostoykye (Kh, fertile and A33 (with a tendency to parthenocarpy have revealed that seed production is affected by disturbances in embryo sac formation but mainly by its degeneration after anthesis, which is especially visible in line A33. Moreover, delayed development of some embryo sacs and incomplete pollination due to various stigma levels seem to be responsible for the diminution of seed number in line A33. Deep fluorescence of numerous pollen grains as well as whole pollen tubes in 83.3 per cent of A33 stigmas and only 24.1 per cent in the Kh line points to the heterogeneity of pollen. This could be one more reason for reduced fertility. The results of application of plant growth regulators (auxin, PCIB which affect seed production in tomato of line A33 remain inconclusive.

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)

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

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

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-.

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)

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

Characterization and quantification of phenolic compounds in four tomato (Lycopersicon esculentum L.) farmers' varieties in northeastern Portugal homegardens.

Science.gov (United States)

Barros, Lillian; Dueñas, Montserrat; Pinela, José; Carvalho, Ana Maria; Buelga, Celestino Santos; Ferreira, Isabel C F R

2012-09-01

Tomato (Lycopersicon esculentum L.) is one of the most widely consumed fresh and processed vegetables in the world, and contains bioactive key components. Phenolic compounds are one of those components and, according to the present study, farmers' varieties of tomato cultivated in homegardens from the northeastern Portuguese region are a source of phenolic compounds, mainly phenolic acid derivatives. Using HPLC-DAD-ESI/MS, it was concluded that a cis p-coumaric acid derivative was the most abundant compound in yellow (Amarelo) and round (Batateiro) tomato varieties, while 4-O-caffeolyquinic acid was the most abundant in long (Comprido) and heart (Coração) varieties. The most abundant flavonoid was quercetin pentosylrutinoside in the four tomato varieties. Yellow tomato presented the highest levels of phenolic compounds (54.23 μg/g fw), including phenolic acids (43.30 μg/g fw) and flavonoids (10.93 μg/g fw). The phenolic compounds profile obtained for the studied varieties is different from other tomato varieties available in different countries, which is certainly related to genetic features, cultivation conditions, and handling and storage methods associated to each sample.

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

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

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

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.

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

Amphitrite ornata dehaloperoxidase (DHP): investigations of structural factors that influence the mechanism of halophenol dehalogenation using "peroxidase-like" myoglobin mutants and "myoglobin-like" DHP mutants.

Science.gov (United States)

Du, Jing; Huang, Xiao; Sun, Shengfang; Wang, Chunxue; Lebioda, Lukasz; Dawson, John H

2011-09-27

Dehaloperoxidase (DHP), discovered in the marine terebellid polychaete Amphitrite ornata, is the first heme-containing globin with a peroxidase activity. The sequence and crystal structure of DHP argue that it evolved from an ancient O(2) transport and storage globin. Thus, DHP retains an oxygen carrier function but also has the ability to degrade halophenol toxicants in its living environment. Sperm whale myoglobin (Mb) in the ferric state has a peroxidase activity ∼10 times lower than that of DHP. The catalytic activity enhancement observed in DHP appears to have been generated mainly by subtle changes in the positions of the proximal and distal histidine residues that appeared during DHP evolution. Herein, we report investigations into the mechanism of action of DHP derived from examination of "peroxidase-like" Mb mutants and "Mb-like" DHP mutants. The dehalogenation ability of wild-type Mb is augmented in the peroxidase-like Mb mutants (F43H/H64L, G65T, and G65I Mb) but attenuated in the Mb-like T56G DHP variant. X-ray crystallographic data show that the distal His residues in G65T Mb and G65I are positioned ∼0.3 and ∼0.8 Å, respectively, farther from the heme iron compared to that in the wild-type protein. The H93K/T95H double mutant Mb with the proximal His shifted to the "DHP-like" position has an increased peroxidase activity. In addition, a better dehaloperoxidase (M86E DHP) was generated by introducing a negative charge near His89 to enhance the imidazolate character of the proximal His. Finally, only minimal differences in dehalogenation activities are seen among the exogenous ligand-free DHP, the acetate-bound DHP, and the distal site blocker L100F DHP mutant. Thus, we conclude that binding of halophenols in the internal binding site (i.e., distal cavity) is not essential for catalysis. This work provides a foundation for a new structure-function paradigm for peroxidases and for the molecular evolution of the dual-function enzyme DHP.

Amphitrite ornata Dehaloperoxidase (DHP): Investigations of Structural Factors That Influence the Mechanism of Halophenol Dehalogenation Using ;Peroxidase-like; Myoglobin Mutants and ;Myoglobin-like; DHP Mutants

Energy Technology Data Exchange (ETDEWEB)

Du, Jing; Huang, Xiao; Sun, Shengfang; Wang, Chunxue; Lebioda, Lukasz; Dawson, John H. (SC)

2012-05-14

Dehaloperoxidase (DHP), discovered in the marine terebellid polychaete Amphitrite ornata, is the first heme-containing globin with a peroxidase activity. The sequence and crystal structure of DHP argue that it evolved from an ancient O{sub 2} transport and storage globin. Thus, DHP retains an oxygen carrier function but also has the ability to degrade halophenol toxicants in its living environment. Sperm whale myoglobin (Mb) in the ferric state has a peroxidase activity {approx}10 times lower than that of DHP. The catalytic activity enhancement observed in DHP appears to have been generated mainly by subtle changes in the positions of the proximal and distal histidine residues that appeared during DHP evolution. Herein, we report investigations into the mechanism of action of DHP derived from examination of 'peroxidase-like' Mb mutants and 'Mb-like' DHP mutants. The dehalogenation ability of wild-type Mb is augmented in the peroxidase-like Mb mutants (F43H/H64L, G65T, and G65I Mb) but attenuated in the Mb-like T56G DHP variant. X-ray crystallographic data show that the distal His residues in G65T Mb and G65I are positioned {approx}0.3 and {approx}0.8 {angstrom}, respectively, farther from the heme iron compared to that in the wild-type protein. The H93K/T95H double mutant Mb with the proximal His shifted to the 'DHP-like' position has an increased peroxidase activity. In addition, a better dehaloperoxidase (M86E DHP) was generated by introducing a negative charge near His89 to enhance the imidazolate character of the proximal His. Finally, only minimal differences in dehalogenation activities are seen among the exogenous ligand-free DHP, the acetate-bound DHP, and the distal site blocker L100F DHP mutant. Thus, we conclude that binding of halophenols in the internal binding site (i.e., distal cavity) is not essential for catalysis. This work provides a foundation for a new structure-function paradigm for peroxidases and for the

An Internal Disulfide Locks a Misfolded Aggregation-prone Intermediate in Cataract-linked Mutants of Human γD-Crystallin.

Science.gov (United States)

Serebryany, Eugene; Woodard, Jaie C; Adkar, Bharat V; Shabab, Mohammed; King, Jonathan A; Shakhnovich, Eugene I

2016-09-02

Considerable mechanistic insight has been gained into amyloid aggregation; however, a large number of non-amyloid protein aggregates are considered "amorphous," and in most cases, little is known about their mechanisms. Amorphous aggregation of γ-crystallins in the eye lens causes cataract, a widespread disease of aging. We combined simulations and experiments to study the mechanism of aggregation of two γD-crystallin mutants, W42R and W42Q: the former a congenital cataract mutation, and the latter a mimic of age-related oxidative damage. We found that formation of an internal disulfide was necessary and sufficient for aggregation under physiological conditions. Two-chain all-atom simulations predicted that one non-native disulfide in particular, between Cys(32) and Cys(41), was likely to stabilize an unfolding intermediate prone to intermolecular interactions. Mass spectrometry and mutagenesis experiments confirmed the presence of this bond in the aggregates and its necessity for oxidative aggregation under physiological conditions in vitro Mining the simulation data linked formation of this disulfide to extrusion of the N-terminal β-hairpin and rearrangement of the native β-sheet topology. Specific binding between the extruded hairpin and a distal β-sheet, in an intermolecular chain reaction similar to domain swapping, is the most probable mechanism of aggregate propagation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

An Internal Disulfide Locks a Misfolded Aggregation-prone Intermediate in Cataract-linked Mutants of Human γD-Crystallin*

Science.gov (United States)

Serebryany, Eugene; Woodard, Jaie C.; Adkar, Bharat V.; Shabab, Mohammed; King, Jonathan A.; Shakhnovich, Eugene I.

2016-01-01

Considerable mechanistic insight has been gained into amyloid aggregation; however, a large number of non-amyloid protein aggregates are considered “amorphous,” and in most cases, little is known about their mechanisms. Amorphous aggregation of γ-crystallins in the eye lens causes cataract, a widespread disease of aging. We combined simulations and experiments to study the mechanism of aggregation of two γD-crystallin mutants, W42R and W42Q: the former a congenital cataract mutation, and the latter a mimic of age-related oxidative damage. We found that formation of an internal disulfide was necessary and sufficient for aggregation under physiological conditions. Two-chain all-atom simulations predicted that one non-native disulfide in particular, between Cys32 and Cys41, was likely to stabilize an unfolding intermediate prone to intermolecular interactions. Mass spectrometry and mutagenesis experiments confirmed the presence of this bond in the aggregates and its necessity for oxidative aggregation under physiological conditions in vitro. Mining the simulation data linked formation of this disulfide to extrusion of the N-terminal β-hairpin and rearrangement of the native β-sheet topology. Specific binding between the extruded hairpin and a distal β-sheet, in an intermolecular chain reaction similar to domain swapping, is the most probable mechanism of aggregate propagation. PMID:27417136

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)

[Bioaccumulation of cadmium and zinc in tomato (Lycopersicon esculentum L.)].

Science.gov (United States)

Sbartai, Hana; Djebar, Med Reda; Sbartai, Ibtissem; Berrabbah, Houria

2012-09-01

This work aims at evaluating the accumulation of cadmium (Cd) and zinc (Zn) (trace elements) in the organs of young tomato plants (Lycopersicon esculentum L. var. Rio Grande) and their effects on the rate of chlorophyll and enzyme activities involved in the antioxidant system: catalase (CAT), glutathion-S-transferase (GST) and peroxysase ascorbate (APX). Plants previously grown on a basic nutrient solution were undergoing treatment for 7 days, either by increasing concentrations of CdCl(2) or ZnSO(4) (0, 50, 100, 250, 500 μM) or by the combined concentrations of Cd and Zn (100/50, 100/100, 100/250, 100/500 μM). The results concerning the determination of metals in the various compartments of tomato plants as a function of increasing concentrations of Cd or Zn, suggest a greater accumulation of Cd and Zn in the roots compared to leaves. The combined treatment (Cd/Zn) interferes with the absorption of the two elements according to their concentrations in the culture medium. The presence of Zn at low concentrations (50 μM of Zn/100 μM Cd) has little influence on the accumulation of Cd in the roots and leaves, while the absorption of these two elements in the leaves increases and decreases in roots when their concentrations are equivalent (100/100 μM) compared to treatment alone. When the concentration of Zn is higher than that of Cd (500 μM of Zn/100 μM Cd) absorption of the latter is inhibited in the roots while increasing their translocation to the leaves. Meanwhile, the dosage of chlorophylls shows that they tend to decrease in a dose-dependent for both treatments (Cd or Cd/Zn), however, treatment with low concentrations of Zn (50 and 100 μM) stimulates chlorophyll synthesis. However, treatment with different concentrations of Cd seems to induce the activity of the enzymes studied (CAT, APX, GST). It is the same for treatment with different concentrations of Zn and this particularly for the highest concentrations. Finally, the combined treatment (Zn

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

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

Study of radiation in fresh tomatoes (lycopersicon esculentum Mill) and in the levels of sauce lycopene

International Nuclear Information System (INIS)

Fabbri, Adriana Diaz Toni

2009-01-01

The purpose of the present study was to determine the effects of ionizing radiation in tomatoes (Lycopersicon esculentum Mill) and at the same time to evaluate the influence of irradiation on the content of lycopene in a sauce made with these fruits irradiated. For this reason tomatoes were subjected to five treatments: control, T1 (0.25 kGy), T2 (0.5 kGy), T3 (1.0 kGy) and T4 (2.0 kGy) and evaluated at 3, 6, 9, 12, 15 and 20 days after irradiation, for the following analysis: maturity, texture, color, soluble solids, pH, acidity and total mass. Measurements were made of lycopene in fresh tomatoes and sauce by open column chromatography according to the ripening of them. The results showed that only the mass was not significantly different (p> 0.05). Treatments 1 and 2 proved to be effective in delaying the maturation and in the maintenance of firm texture (p 0.05) when compared to control. However, it didn't indicate lycopene degradation, as the doses of 1.0 and 2.0 kGy. Thus we can conclude that low doses are effective for maintaining pH, firmness, delayed senescence, mass and, in addition to not degrading the major bioactive compound of tomato, lycopene, suggest a higher bioavailability of this one, depending on the radiation application. (author)

Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

Science.gov (United States)

Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C

2016-06-02

We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10(-4) M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10(-5) M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants.

Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby

Science.gov (United States)

Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C.

2016-01-01

ABSTRACT We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10−4 M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10−5 M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants. PMID:27348536

Increase in the rate of recombinants in tomato (Lycopersicon esculentum L.) after in vitro regeneration.

Science.gov (United States)

Sibi, M; Biglary, M; Demarly, Y

1984-07-01

Modification to the cross-over (C. O.) rate of tomato (Lycopersicon esculentum) was attempted by using in vitro plant regeneration. F1 hybrids with the same genetical homozygous background were compared at two loci: "bs-ms32" on chromosome I, and "aa-d" on chromosome II. For each, the genetic distance separating the two markers was about 20 to 30 map units. One cotyledon of each F2 hybrid seedling was used as in vitro tissue culture material, while the rest of the plantlet was grown as a control. Recombination rates of the selfed progenies from each regenerated and matched control couple were compared. For the first set of markers 59,000 seeds were analysed (5 controls' and 7 regenerated progenies), and for the second, 11,000 (5 controls' and 8 regenerated progenies). There were significant increases in the genetic distance between markers in about half the regenerated individuals. For the first set the increases ranged from 6.07 to 6.91 units out of a control distance of the 19.84 to 25.65, corresponding to lengthenings of 30.59 to 35.29%. For the second set they ranged from 4.92 to 6.04 out of a control distance of 25.05 to 26.57, representing increases of 19.64 to 22.75%. Such a phenomenon can be important either from a fundamental or practical viewpoint, regarding selection efficiency in plants, and potential for gene reassortment.

Brucellosis vaccines: assessment of Brucella melitensis lipopolysaccharide rough mutants defective in core and O-polysaccharide synthesis and export.

Directory of Open Access Journals (Sweden)

David González

Full Text Available BACKGROUND: The brucellae are facultative intracellular bacteria that cause brucellosis, one of the major neglected zoonoses. In endemic areas, vaccination is the only effective way to control this disease. Brucella melitensis Rev 1 is a vaccine effective against the brucellosis of sheep and goat caused by B. melitensis, the commonest source of human infection. However, Rev 1 carries a smooth lipopolysaccharide with an O-polysaccharide that elicits antibodies interfering in serodiagnosis, a major problem in eradication campaigns. Because of this, rough Brucella mutants lacking the O-polysaccharide have been proposed as vaccines. METHODOLOGY/PRINCIPAL FINDINGS: To examine the possibilities of rough vaccines, we screened B. melitensis for lipopolysaccharide genes and obtained mutants representing all main rough phenotypes with regard to core oligosaccharide and O-polysaccharide synthesis and export. Using the mouse model, mutants were classified into four attenuation patterns according to their multiplication and persistence in spleens at different doses. In macrophages, mutants belonging to three of these attenuation patterns reached the Brucella characteristic intracellular niche and multiplied intracellularly, suggesting that they could be suitable vaccine candidates. Virulence patterns, intracellular behavior and lipopolysaccharide defects roughly correlated with the degree of protection afforded by the mutants upon intraperitoneal vaccination of mice. However, when vaccination was applied by the subcutaneous route, only two mutants matched the protection obtained with Rev 1 albeit at doses one thousand fold higher than this reference vaccine. These mutants, which were blocked in O-polysaccharide export and accumulated internal O-polysaccharides, stimulated weak anti-smooth lipopolysaccharide antibodies. CONCLUSIONS/SIGNIFICANCE: The results demonstrate that no rough mutant is equal to Rev 1 in laboratory models and question the notion that

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

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

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)

Whole-Genome Sequencing of Sordaria macrospora Mutants Identifies Developmental Genes.

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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.

Olive mill wastewater triggered changes in physiology and nutritional quality of tomato (Lycopersicon esculentum mill) depending on growth substrate.

Science.gov (United States)

Ouzounidou, G; Asfi, M; Sotirakis, N; Papadopoulou, P; Gaitis, F

2008-10-30

We have studied the changes in the physiology and nutritional quality of Lycopersicon esculentum exposed to olive mill wastewater (OMW) with regard to cultivation in sand and soil. Tomato plant performance decreased with increasing concentration of OMW to both substrates. Root was more sensitive to OMW than the upper parts of the plants, grown either in sand or in soil for 10 days and 3 months, respectively, probably due to the direct OMW toxicity on roots as compared to other parts. Significant restriction on uptake and translocation of nutrients (K, Na, Fe, Ca and Mg) under OMW application was found. The decrease in the photochemical efficiency of PSII photochemistry in the light adapted state and the big decrease in photochemical quenching, indicate that OMW resulted in diminished reoxidation of Q(A)(-) and started to inactivate the reaction centers of PSII. The OMW supply on soil and sand, resulted in leaf water stress and lesser water use efficiency. Plants treated with high OMW concentration, produced fewer but bigger tomatoes as compared to plants treated with lower OMW concentration. Generally, fruit yield and nutritional value was inhibited under OMW application.

Mode of inheritance of irradiation induced dwarfism and male sterility in the tomato, Lycopersicon esculentum

International Nuclear Information System (INIS)

Garofalo, J.F.

1975-01-01

Seedlings of the Louisiana tomato cultivar ''Pelican'' were irradiated in the cotyledonary stage with 10,000 roentgen (R) of gamma radiation from 60 Co at 1.67 R/min by Dr. Milton J. Constantin, Comparative Animal Research Laboratory operated by the University of Tennessee for the Atomic Energy Commission. From these irradiated plants one dwarf and six stamenless mutants were selected and propagated. In 1973 to 1974 a genetic study was conducted to determine the mode of inheritance of these mutant characters. Also a combining ability study was conducted to determine the potential value of the dwarf mutant as a parent in the production of F 1 hybrid seed. The results of the genetic study showed that the induced dwarf character was simply inherited and recessive. Results indicate that this gene is probably located at a locus different from that of genes controlling dwarfism in other tomato lines. The combining ability study showed that this dwarf mutant is of little value as a breeding parent. The genetic study of the stamenless lines showed this character to be simply inherited and recessive. It was also shown that the gene controlling male sterility is located at the same locus in the lines L 39 and L 43, and it is assumed that the same locus is involved in all six lines. The stamenless lines have, as far as has been observed, retained the good combining ability of the original parent cultivar ''Pelican''

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

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

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)

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.

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

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.

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)

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.

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.

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.

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)

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 ...

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

Exploring genetic variation in the tomato (Solanum section Lycopersicon) clade by whole-genome sequencing.

Science.gov (United States)

Aflitos, Saulo; Schijlen, Elio; de Jong, Hans; de Ridder, Dick; Smit, Sandra; Finkers, Richard; Wang, Jun; Zhang, Gengyun; Li, Ning; Mao, Likai; Bakker, Freek; Dirks, Rob; Breit, Timo; Gravendeel, Barbara; Huits, Henk; Struss, Darush; Swanson-Wagner, Ruth; van Leeuwen, Hans; van Ham, Roeland C H J; Fito, Laia; Guignier, Laëtitia; Sevilla, Myrna; Ellul, Philippe; Ganko, Eric; Kapur, Arvind; Reclus, Emannuel; de Geus, Bernard; van de Geest, Henri; Te Lintel Hekkert, Bas; van Haarst, Jan; Smits, Lars; Koops, Andries; Sanchez-Perez, Gabino; van Heusden, Adriaan W; Visser, Richard; Quan, Zhiwu; Min, Jiumeng; Liao, Li; Wang, Xiaoli; Wang, Guangbiao; Yue, Zhen; Yang, Xinhua; Xu, Na; Schranz, Eric; Smets, Erik; Vos, Rutger; Rauwerda, Johan; Ursem, Remco; Schuit, Cees; Kerns, Mike; van den Berg, Jan; Vriezen, Wim; Janssen, Antoine; Datema, Erwin; Jahrman, Torben; Moquet, Frederic; Bonnet, Julien; Peters, Sander

2014-10-01

We explored genetic variation by sequencing a selection of 84 tomato accessions and related wild species representative of the Lycopersicon, Arcanum, Eriopersicon and Neolycopersicon groups, which has yielded a huge amount of precious data on sequence diversity in the tomato clade. Three new reference genomes were reconstructed to support our comparative genome analyses. Comparative sequence alignment revealed group-, species- and accession-specific polymorphisms, explaining characteristic fruit traits and growth habits in the various cultivars. Using gene models from the annotated Heinz 1706 reference genome, we observed differences in the ratio between non-synonymous and synonymous SNPs (dN/dS) in fruit diversification and plant growth genes compared to a random set of genes, indicating positive selection and differences in selection pressure between crop accessions and wild species. In wild species, the number of single-nucleotide polymorphisms (SNPs) exceeds 10 million, i.e. 20-fold higher than found in most of the crop accessions, indicating dramatic genetic erosion of crop and heirloom tomatoes. In addition, the highest levels of heterozygosity were found for allogamous self-incompatible wild species, while facultative and autogamous self-compatible species display a lower heterozygosity level. Using whole-genome SNP information for maximum-likelihood analysis, we achieved complete tree resolution, whereas maximum-likelihood trees based on SNPs from ten fruit and growth genes show incomplete resolution for the crop accessions, partly due to the effect of heterozygous SNPs. Finally, results suggest that phylogenetic relationships are correlated with habitat, indicating the occurrence of geographical races within these groups, which is of practical importance for Solanum genome evolution studies. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

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

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).

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.

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

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 .

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

Identification of the pI 4.6 extensin peroxidase from Lycopersicon esculentum using proteomics and reverse-genomics.

Science.gov (United States)

Dong, Wen; Kieliszewski, Marcia; Held, Michael A

2015-04-01

The regulation of plant cell growth and early defense response involves the insolubilization of hydroxyproline-rich glycoproteins (HRGPs), such as extensin, in the primary cell wall. In tomato (Lycopersicon esculentum), insolubilization occurs by the formation of tyrosyl-crosslinks catalyzed specifically by the pI 4.6 extensin peroxidase (EP). To date, neither the gene encoding EP nor the protein itself has been identified. Here, we have identified tomato EP candidates using both proteomic and bioinformatic approaches. Bioinformatic screening of the tomato genome yielded eight EP candidates, which contained a putative signal sequence and a predicted pI near 4.6. Biochemical fractionation of tomato culture media followed by proteomic detection further refined our list of EP candidates to three, with the lead candidate designated (CG5). To test for EP crosslinking activity, we cloned into a bacterial expression vector the CG5 open-reading frame from tomato cDNA. The CG5 was expressed in Escherichia coli, fractionated from inclusion bodies, and folded in vitro. The peroxidase activity of CG5 was assayed and quantified by ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) assay. Subsequent extensin crosslinking assays showed that CG5 can covalently crosslink authentic tomato P1 extensin and P3-type extensin analogs in vitro supporting our hypothesis that CG5 encodes a tomato EP. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

Synthesis, purification, and characterization of an Arg152 → Glu site-directed mutant of recombinant human blood clotting factor VII

International Nuclear Information System (INIS)

Wildgoose, P.; Kisiel, W.; Berkner, K.L.

1990-01-01

Coagulation factor VII circulates in blood as a single-chain zymogen of a serine protease and is converted to its activated two-chain form, factor VIIa, by cleavage of an internal peptide bond located at Arg 152 -Ile 153 . Previous studies using serine protease active-site inhibitors suggest that zymogen factor VII may possess sufficient proteolytic activity to initiate the extrinsic pathway of blood coagulation. In order to assess the putative intrinsic proteolytic activity of single-chain factor VII, the authors have constructed a site-specific mutant of recombinant human factor VII in which arginine-152 has been replaced with a glutamic acid residue. Mutant factor VII was purified in a single step from culture supernatants of baby hamster kidney cells transfected with a plasmid containing the sequence for Arg 152 → Glu factor VII using a calcium-dependent, murine anti-factor VII monoclonal antibody column. The clotting activity of mutant factor VII was completely inhibited following incubation with dansyl-Glu-Gly-Arg chloromethyl ketone, suggesting that the apparent clotting activity of mutant factor VII was due to a contaminating serine protease. Immunoblots of mutant factor VII with human factor IXa revealed no cleavage, whereas incubation of mutant factor VII with human factor Xa resulted in cleavage of mutant factor VII and the formation of a lower molecular weight degradation product migrating at M r ∼40 000. The results are consistent with the proposal that zymogen factor VII possesses no intrinsic proteolytic activity toward factor X or factor IX

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

El efecto de la disponibilidad de agua durante el crecimiento de Lycopersicon chilense sobre la capacidad de sus semillas para germinar a distintas temperaturas y concentraciones de manitol y NaCl Effect of water availability during the growth of Lycopersicon chilense on the capacity of their seeds to germinate at different temperatures and concentrations of manitol and NaCl

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CARLOS MALDONADO

2002-12-01

Full Text Available El número de semillas producidas por una planta puede estar limitada por factores ambientales adversos, los cuales también pueden afectar el desarrollo, originando semillas no viables. En la Primera Región de Chile hemos observado que Lycopersicon chilense, una especie de tomate endémica del Desierto de Atacama, presenta una alta producción de frutos y de semillas, sin embargo se observa una escasa regeneración de nuevos individuos. Se plantea que esto se debe a dos factores: (a las plantas madres, producto de las condiciones adversas donde crecen desarrollan semillas no viables o (b las semillas son viables pero las condiciones ambientales son desfavorables para la germinación. Se estudió la capacidad germinativa de semillas de Lycopersicon chilense sometidas a distintas temperaturas y concentraciones de manitol y NaCl, provenientes de plantas madres que crecieron con buen abastecimiento hídrico (+H2O y de otro grupo que creció con un abastecimiento hídrico deficiente (-H2O. El nivel de riego tuvo un efecto sobre el número de semillas germinadas y sobre el tiempo que necesitan las semillas para germinar frente a distintas temperaturas y diferentes potenciales hídricos. Las semillas de plantas -H2O fueron capaces de germinar a potenciales hídricos más negativos y en menor tiempo que las semillas provenientes de plantas +H2O en el caso de manitol. Una relación inversa ocurrió respecto a NaCl, en que un mayor porcentaje de germinación y un menor tiempo de germinación se presentó en las semillas provenientes de plantas +H2O. La germinación de L. chilense disminuye progresivamente a potenciales hídricos menores de -0,5 MPa siendo esta disminución más notoria con NaCl, en ambos casos se observó un retraso en la germinación. El óptimo de temperatura para la germinación se encontró entre los 15 y los 25 °C. Lycopersicon chilense no germinó a temperaturas menores de 8 °C y mayores de 35 °C. Los datos mostraron que las

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

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.

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)

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.

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.)

Functional analysis of chloroplast early light inducible proteins (ELIPs)

Energy Technology Data Exchange (ETDEWEB)

Wetzel, Carolyn M

2005-02-22

The objectives of this project were to characterize gene expression patterns of early light inducible protein (ELIP) genes in Arabidopsis thaliana and in Lycopersicon esculentum, to identify knock mutants of the 2 ELIP genes in Arabidopsis, and to characterize the effects of the knockouts. Expression in Arabidopsis was studied in response to thylakoid electron transport chain (PETC) capacity, where it was found that there is a signal for expression associated with reduction of the PETC. Expression in response to salt was also studied, with different responses of the two gene copies. Knockout lines for ELIP1 and ELIP2 have been identified and are being characterized. In tomato, it was found that the single-copy ELIP gene is highly expressed in ripening fruit during the chloroplast-to-chromoplast transition. Studies of expression in tomato ripening mutants are ongoing.

Growth and development of tomato plants Lycopersicon Esculentum Mill. under different saline conditions by fertirrigation with pretreated cheese whey wastewater.

Science.gov (United States)

Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse

2013-01-01

Pretreated cheese whey wastewater (CWW) has been used at different salinity levels: 1.75, 2.22, 3.22, 5.02 and 10.02 dS m(-1) and compared with fresh water (1.44 dS m(-1)). Two cultivars (cv.) of the tomato plant Lycopersicon Esculentum Mill. (Roma and Rio Grande) were exposed to saline conditions for 72 days. Salinity level (treatment) had no significant effects on the fresh weight and dry matter of the leaves, stems and roots. Similar results were found when specific leaf area, leaflet area, ramifications number of 1st order/plant, stem diameter and length, nodes number/stem and primary root length were considered. Conversely, the salinity level significantly influenced the Soil Plant Analysis Development (SPAD) index and the distance between nodes in the plant stem. In the first case, an increase of 21% was obtained in the salinity levels of 5.02 and 10.02 dS m(-1) for cv. Rio Grande, compared with the control run. The results showed that the pretreated CWW can be a source of nutrients for tomato plants, with reduced effects on growth and development.

Lectin conjugates as biospecific contrast agents for MRI. Coupling of Lycopersicon esculentum agglutinin to linear water-soluble DTPA-loaded oligomers.

Science.gov (United States)

Pashkunova-Martic, Irena; Kremser, Christian; Galanski, Markus; Schluga, Petra; Arion, Vladimir; Debbage, Paul; Jaschke, Werner; Keppler, Bernhard

2011-06-01

Magnetic resonance imaging (MRI) requires synthesis of contrast media bearing targeting groups and numerous gadolinium chelating groups generating high relaxivity. This paper explores the results of linking the gadolinium chelates to the targeting group, a protein molecule, via various types of linkers. Polycondensates of diethylenetriaminepentaacetic acid (DTPA) with either diols or diamines were synthesised and coupled to the targeting group, a lectin (Lycopersicon esculentum agglutinin, tomato lectin) which binds with high affinity to specific oligosaccharide configurations in the endothelial glycocalyx. The polycondensates bear up to four carboxylic groups per constitutive unit. Gd-chelate bonds are created through dative interactions with the unshared pair of electrons on each oxygen and nitrogen atom on DTPA. This is mandatory for complexation of Gd(III) and avoidance of the severe toxicity of free gadolinium ions. The polymer-DTPA compounds were characterised by (1)H NMR and mass spectrometry. The final lectin-DTPA-polycondensate conjugates were purified by fast protein liquid chromatography (FPLC). The capacity for specific binding was assessed, and the MRI properties were examined in order to evaluate the use of these oligomers as components of selective perfusional contrast agents.

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.

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

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)

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)

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)

Mutants of Yarrowia lipolytica NCIM 3589 grown on waste cooking oil as a biofactory for biodiesel production.

Science.gov (United States)

Katre, Gouri; Ajmera, Namasvi; Zinjarde, Smita; RaviKumar, Ameeta

2017-10-24

Oleaginous yeasts are fast emerging as a possible feedstock for biodiesel production. Yarrowia lipolytica, a model oleaginous yeast is known to utilize a variety of hydrophobic substrates for lipid accumulation including waste cooking oil (WCO). Approaches to increase lipid content in this yeast include metabolic engineering which requires manipulation of multiple genes in the lipid biosynthesis pathway. A classical and cost-effective approach, namely, random chemical mutagenesis on the yeast can lead to increased production of biodiesel as is explored here. In this study, chemical mutagenesis using the alkylating agent, N- methyl-N'-nitro-N-nitrosoguanidine (MNNG) as well as an additional treatment with cerulenin, a fatty acid synthase inhibitor generated 800 mutants of Y. lipolytica NCIM 3589 (761 MNNG treated and 39 MNNG + cerulenin treated). A three-stage screening using Sudan Black B plate technique, Nile red fluorimetry and total lipid extraction using solvent was performed, which enabled selection of ten high lipid yielding mutants. Time course studies of all the ten mutants were further undertaken in terms of biomass, lipid yield and lipid content to select three stable mutants (YlB6, YlC7 and YlE1) capable of growing and accumulating lipid on WCO, with lipid contents of 55, 60 and 67% as compared to 45% for the wild type. The mutants demonstrated increased volumetric lipid productivities (0.062, 0.044 and 0.041 g L -1  h -1 ) as compared to the wild type (0.033 g L -1  h -1 ). The fatty acid profile of the three mutants consisted of a high content of C16 and C18 saturated and monounsaturated fatty acids and was found to be suitable for biodiesel production. The fuel properties, namely, density, kinematic viscosity, total acid number, iodine value of the three mutants were evaluated and found to lie within the limits specified by internationally accepted standards. Additionally, it was noted that the mutants demonstrated better cetane numbers and

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.

Defective glycinergic synaptic transmission in zebrafish motility mutants

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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.

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

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.)

Histological and Molecular Characterization of Grape Early Ripening Bud Mutant

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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.

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.

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

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)

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)

Synthesis, purification, and characterization of an Arg sub 152 yields Glu site-directed mutant of recombinant human blood clotting factor VII

Energy Technology Data Exchange (ETDEWEB)

Wildgoose, P.; Kisiel, W. (Univ. of New Mexico, Albuquerque (USA)); Berkner, K.L. (ZymoGenetics, Inc., Seattle, WA (USA))

1990-04-03

Coagulation factor VII circulates in blood as a single-chain zymogen of a serine protease and is converted to its activated two-chain form, factor VIIa, by cleavage of an internal peptide bond located at Arg{sub 152}-Ile{sub 153}. Previous studies using serine protease active-site inhibitors suggest that zymogen factor VII may possess sufficient proteolytic activity to initiate the extrinsic pathway of blood coagulation. In order to assess the putative intrinsic proteolytic activity of single-chain factor VII, the authors have constructed a site-specific mutant of recombinant human factor VII in which arginine-152 has been replaced with a glutamic acid residue. Mutant factor VII was purified in a single step from culture supernatants of baby hamster kidney cells transfected with a plasmid containing the sequence for Arg{sub 152} {yields} Glu factor VII using a calcium-dependent, murine anti-factor VII monoclonal antibody column. The clotting activity of mutant factor VII was completely inhibited following incubation with dansyl-Glu-Gly-Arg chloromethyl ketone, suggesting that the apparent clotting activity of mutant factor VII was due to a contaminating serine protease. Immunoblots of mutant factor VII with human factor IXa revealed no cleavage, whereas incubation of mutant factor VII with human factor Xa resulted in cleavage of mutant factor VII and the formation of a lower molecular weight degradation product migrating at M{sup r}{approx}40 000. The results are consistent with the proposal that zymogen factor VII possesses no intrinsic proteolytic activity toward factor X or factor IX.

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)

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

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)

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

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

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)

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

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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

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

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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.

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.

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)

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 ...

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)

Padrão de identidade e qualidade do tomate (Lycopersicon esculentum Mill. de mesa

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Ferreira Sila Mary Rodrigues

2004-01-01

Full Text Available O valor comercial do tomate, Lycopersicon esculentum Mill., é definido pelas características de identidade e qualidade presentes no fruto que podem ser avaliadas pela classificação do produto. A presente revisão de literatura teve como objetivo descrever o padrão de identidade e qualidade do tomate de mesa, através da classificação. O tomate de mesa é classificado em grupos, subgrupos, classes e tipos. De acordo com o formato do fruto, o tomate é classificado em dois grupos: oblongo, quando o diâmetro longitudinal é maior que o transversal e redondo, quando o diâmetro longitudinal é menor ou igual ao transversal. Em função do estádio de maturação, o tomate é classificado em cinco subgrupos: verde maduro, pintado, rosado, vermelho e vermelho maduro. A classe é definida em função do maior diâmetro transversal do fruto em relação ao grupo a que pertença. O tomate oblongo é classificado em três classes: grande, médio e pequeno. O tomate redondo é classificado em quatro classes: gigante, grande, médio e pequeno. De acordo com os índices de ocorrência de defeitos graves e leves presentes nos frutos, o tomate é classificado também em tipo: extra, especial ou selecionado e comercial. São considerados defeitos graves: podridão, passado, queimado, dano por geada, podridão apical, e defeitos leves: dano, mancha, ocado, deformado e imaturo. A amostra de tomate que ultrapasse os índices de defeitos previstos pela legislação do Ministério da Agricultura é classificada como fora do padrão.

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

Construindo Marcas Mutantes

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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.

Interferon β induces clearance of mutant ataxin 7 and improves locomotion in SCA7 knock-in mice.

Science.gov (United States)

Chort, Alice; Alves, Sandro; Marinello, Martina; Dufresnois, Béatrice; Dornbierer, Jean-Gabriel; Tesson, Christelle; Latouche, Morwena; Baker, Darren P; Barkats, Martine; El Hachimi, Khalid H; Ruberg, Merle; Janer, Alexandre; Stevanin, Giovanni; Brice, Alexis; Sittler, Annie

2013-06-01

We showed previously, in a cell model of spinocerebellar ataxia 7, that interferon beta induces the expression of PML protein and the formation of PML protein nuclear bodies that degrade mutant ataxin 7, suggesting that the cytokine, used to treat multiple sclerosis, might have therapeutic value in spinocerebellar ataxia 7. We now show that interferon beta also induces PML-dependent clearance of ataxin 7 in a preclinical model, SCA7(266Q/5Q) knock-in mice, and improves motor function. Interestingly, the presence of mutant ataxin 7 in the mice induces itself the expression of endogenous interferon beta and its receptor. Immunohistological studies in brains from two patients with spinocerebellar ataxia 7 confirmed that these modifications are also caused by the disease in humans. Interferon beta, administered intraperitoneally three times a week in the knock-in mice, was internalized with its receptor in Purkinje and other cells and translocated to the nucleus. The treatment induced PML protein expression and the formation of PML protein nuclear bodies and decreased mutant ataxin 7 in neuronal intranuclear inclusions, the hallmark of the disease. No reactive gliosis or other signs of toxicity were observed in the brain or internal organs. The performance of the SCA7(266Q/5Q) knock-in mice was significantly improved on two behavioural tests sensitive to cerebellar function: the Locotronic® Test of locomotor function and the Beam Walking Test of balance, motor coordination and fine movements, which are affected in patients with spinocerebellar ataxia 7. In addition to motor dysfunction, SCA7(266Q/5Q) mice present abnormalities in the retina as in patients: ataxin 7-positive neuronal intranuclear inclusions that were reduced by interferon beta treatment. Finally, since neuronal death does not occur in the cerebellum of SCA7(266Q/5Q) mice, we showed in primary cell cultures expressing mutant ataxin 7 that interferon beta treatment improves Purkinje cell survival.

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

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.

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

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)

Temperature-sensitive host range mutants of herpes simplex virus type 2

International Nuclear Information System (INIS)

Koment, R.W.; Rapp, F.

1975-01-01

Herpesviruses are capable of several types of infection of a host cell. To investigate the early events which ultimately determine the nature of the virus-host cell interaction, a system was established utilizing temperature-sensitive mutants of herpes simplex virus type 2. Four mutants have been isolated which fail to induce cytopathic effects and do not replicate at 39 C in hamster embryo fibroblast cells. At least one mutant is virus DNA negative. Since intracellular complementation is detectable between pairs of mutants, a virus function is known to be temperature sensitive. However, all four mutants induce cytopathic effects and replicate to parental virus levels in rabbit kidney cells at 39 C. This suggests that a host cell function, lacking or nonfunctional in HEF cells but present in rabbit kidney cells at 39 C, is required for the replication of these mutants in hamster embryo fibroblast cells at 39 C. Therefore, we conclude that these mutants are both temperature sensitive and exhibit host range properties

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)

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.

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

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...

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)

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)

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.)

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

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 ...

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)

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

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)

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

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.

Evaluation of some mutant lines of rice induced by gamma radiation treatment 1. mean performance of rice mutants in M4 generation

International Nuclear Information System (INIS)

El-Banna, M.N.; El-Wakil, H.M.F.; Ebaid, R.A.; Sallam, R.A.

2009-01-01

Grains of eight rice mutants; SC 1, SC 6, RTY 1, RTY 3, HY 14, HYI 17, EH 4 and HYPI 22 were secured from Botany Department Faculty of Agriculture Cairo university. The procedures and the methodology for induction these mutants as well as the original mean performance of such mutants are presented else where; Sabbour, (1989) and Sabbour etal. (2002). Grains were sown (M4 generation) at the experimental farm in Itai EI-Baroud Agricultural Research Station Behaira Governorate Agricultural Research Center (ARC) in the summer season (2007). The mean performance of such mutants was studied during M4 generation. The most exciting results were as follows: the selected line SC 1 showed in M4 generation superior agronomic and yield traits. Sc 1 mutant line is not bred truly and it need more generations to reach stability. SC 6 in M4 generation showed considerable number of individuals scored low mean values toward the negative direction and lowering the overall trait mean performance. The rice lines RTY 1 and RTY 3 proved that, the average number of fertile tillers per plant of the selected lines maintained previously recorded mean values of M3 generation in M4. The traits showed significant differences among their progeny that recorded high CV% values as compared with those showed no significant differences. The rice lines HY 14 and HYI 17 showed a true breeding signs and no more breeding generations are required. Rice lines EH 4, showed a considerable reduction in number of days elapsed from date of cultivation till harvest. As, this mutant maintained 86.58 days till heading. Rice mutant line HYPI 22 did not bred truly for the original selected traits (high yield and high protein content) and it still need more generations of selection to reach considerable stability

Biosynthesis of 14C-phytoene from tomato cell suspension cultures (Lycopersicon esculentum) for utilization in prostate cancer cell culture studies.

Science.gov (United States)

Campbell, Jessica K; Rogers, Randy B; Lila, Mary Ann; Erdman, John W

2006-02-08

This work describes the development and utilization of a plant cell culture production approach to biosynthesize and radiolabel phytoene and phytofluene for prostate cancer cell culture studies. The herbicide norflurazon was added to established cell suspension cultures of tomato (Lycopersicon esculentum cv. VFNT cherry), to induce the biosynthesis and accumulation of the lycopene precursors, phytoene and phytofluene, in their natural isomeric forms (15-cis-phytoene and two cis-phytofluene isomers). Norflurazon concentrations, solvent carrier type and concentration, and duration of culture exposure to norflurazon were screened to optimize phytoene and phytofluene synthesis. Maximum yields of both phytoene and phytofluene were achieved after 7 days of treatment with 0.03 mg norflurazon/40 mL fresh medium, provided in 0.07% solvent carrier. Introduction of 14C-sucrose to the tomato cell culture medium enabled the production of 14C-labeled phytoene for subsequent prostate tumor cell uptake studies. In DU 145 prostate tumor cells, it was determined that 15-cis-phytoene and an oxidized product of phytoene were taken up and partially metabolized by the cells. The ability to biosynthesize, radiolabel, and isolate these carotenoids from tomato cell cultures is a novel, valuable methodology for further in vitro and in vivo investigations into the roles of phytoene and phytofluene in cancer chemoprevention.

Nonbehavioral Selection for Pawns, Mutants of PARAMECIUM AURELIA with Decreased Excitability

Science.gov (United States)

Schein, Stanley J.

1976-01-01

The reversal response in Paramecium aurelia is mediated by calcium which carries the inward current during excitation. Electrophysiological studies indicate that strontium and barium can also carry the inward current. Exposure to high concentrations of barium rapidly paralyzes and later kills wild-type paramecia. Following mutagenesis with nitrosoguanidine, seven mutants which continued to swim in the `high-barium' solution were selected. All of the mutants show decreased reversal behavior, with phenotypes ranging from extremely non-reversing (`extreme' pawns) to nearly wild-type reversal behavior (`partial' pawns). The mutations fall into three complementation groups, identical to the pwA, pwB, and pwC genes of Kung et al. (1975). All of the pwA and pwB mutants withstand longer exposure to barium, the pwB mutants surviving longer than the pwA mutants. Among mutants of each gene, survival is correlated with loss of reversal behavior. Double mutants (A–B, A–C, B–C), identified in the exautogamous progeny of crosses between `partial' mutants, exhibited a more extreme non-reversing phenotype than either of their single-mutant (`partial' pawn) parents.———Inability to reverse could be expected from an alteration in the calcium-activated reversal mechanism or in excitation. A normal calcium-activated structure was demonstrated in all pawns by chlorpromazine treatment. In a separate report (Schein, Bennett and Katz 1976) the results of electrophysiological investigations directly demonstrate decreased excitability in all of the mutants, a decrease due to an altered calcium activation. The studies of the genetics, the survival in barium and the electro-physiology of the pawns demonstrate that the pwA and pwB genes have different effects on calcium activation. PMID:1001878

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)

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

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

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

Production and characterization of radiation-sensitive meiotic mutants of Coprinus cinereus

International Nuclear Information System (INIS)

Zolan, M.E.; Tremel, C.J.; Pukkila, P.J.

1988-01-01

We have isolated four gamma-sensitive mutants of the basidiomycete Coprinus cinereus. When homozygous, two of these (rad 3-1 and rad 9-1) produce fruiting bodies with very few viable basidiospores, the products of meiosis in this organism. A less radiation-sensitive allele of RAD 3, rad 3-2, causes no apparent meiotic defect in homozygous strains. Quantitative measurements of oidial survival of rad 3-1;rad 9-1 double mutants compared to the single mutants indicated that rad 3-1 and rad 9-1 mutants are defective in the same DNA repair pathway. In the pew viable basidiospores that are produced by these two strains, essentially normal levels of meiotic recombination can be detected. None of the mutants exhibits increased sensitivity to UV radiation. Cytological examination of meiotic chromosomes from mutant and wild-type fruiting bodies showed that rad 3-1 homozygous strains fail to condense and pair homologous chromosomes during prophase I. Although rad 9-1 strains are successful at chromosome pairing, meiosis is usually not completed in these mutants

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)

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

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''

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

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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.

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)

Nature of mutants induced by ionizing radiation in cultured hamster cells. II. Antigenic response and reverse mutation of HPRT-deficient mutants induced by. gamma. -rays or ethyl methanesulphonate

Energy Technology Data Exchange (ETDEWEB)

Brown, R; Stretch, A; Thacker, J

1986-04-01

A large series of independent mutants deficient in HPRT enzyme activity, isolated from V79-4 hamster cells, were assessed for properties which reflect the nature of the genetic changes induced. A total of 88 mutants were screened, 43 isolated from ..gamma..-ray-treated cultures and 45 induced by ethyl methanesulphonate (EMS). Firstly, each mutant was assayed for the presence of protein with the antigenic response of HPRT. In a competitive inhibition assay, 31% of EMS-induced mutants were CRM-positive compared to 7% of the ..gamma..-ray series. Secondly, each mutant was tested for ability to revert to HPRT proficiency. All except 2 of the EMS-induced mutants reverted with ethyl nitrosourea ENU, and many reverted spontaneously, under the given conditions. However reversion was not detected in about 80% of ..gamma..-ray-induced mutants, suggesting that the types of forward mutation caused by ionizing radiation differ qualitatively from those caused by EMS. (Auth.). 30 refs.; 6 figs.; 2 tabs.

Isolation and characterization of xylitol-assimilating mutants of recombinant Saccharomyces cerevisiae.

Science.gov (United States)

Tani, Tatsunori; Taguchi, Hisataka; Fujimori, Kazuhiro E; Sahara, Takehiko; Ohgiya, Satoru; Kamagata, Yoichi; Akamatsu, Takashi

2016-10-01

To clarify the mechanisms of xylitol utilization, three xylitol-assimilating mutants were isolated from recombinant Saccharomyces cerevisiae strains showing highly efficient xylose-utilization. The nucleotide sequences of the mutant genomes were analyzed and compared with those of the wild-type strains and the mutation sites were identified. gal80 mutations were common to all the mutants, and recessive to the wild-type allele. Hence we constructed a gal80Δ mutant and confirmed that the gal80Δ mutant showed a xylitol-assimilation phenotype. When the constructed gal80Δ mutant was crossed with the three isolated mutants, all diploid hybrids showed xylitol assimilation, indicating that the mutations were all located in the GAL80. We analyzed the role of the galactose permease Gal2, controlled by the regulatory protein Gal80, in assimilating xylitol. A gal2Δ gal80Δ double mutant did not show xylitol assimilation, whereas expression of GAL2 under the control of the TDH3 promoter in the GAL80 strain did result in assimilation. These data indicate that Gal2 was needed for xylitol assimilation in the wild-type strain. When the gal80 mutant with an initial cell concentration of A660 = 20 was used for batch fermentation in a complex medium containing 20 g/L xylose or 20 g/L xylitol at pH 5.0 and 30°C under oxygen limitation, the gal80 mutant consumed 100% of the xylose within 12 h, but xylitol within 100 h, indicating that xylose reductase is required for xylitol consumption in oxygen-limited conditions. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

24-Epibrassinoslide enhances plant tolerance to stress from low temperatures and poor light intensities in tomato (Lycopersicon esculentum Mill.).

Science.gov (United States)

Cui, Lirong; Zou, Zhirong; Zhang, Jing; Zhao, Yanyan; Yan, Fei

2016-01-01

Brassinosteroids (Brs) are a newly recognized group of active steroidal hormones that occur at low concentrations in all plant parts and one of the active and stable forms is 24-epibrassinolide (EBR). We investigated the effect of EBR on tomato (Lycopersicon esculentum Mill.) and its mechanism when seedlings were exposed to low temperature and poor light stress conditions. Leaves of stress-tolerant 'Zhongza9' and stress-sensitive 'Zhongshu4' cultivars were pre-treated with spray solutions containing either 0.1 μM EBR or no EBR (control). The plants were then transferred to chambers where they were exposed to low temperatures of 12 °C/6 °C (day/night) under a low light (LL) level of 80 μmol · m(-2) · s(-1). Exogenous application of EBR significantly increased the antioxidant activity of superoxide dismutase, catalase and peroxidase, and decreased the rate of O2 · (-) formation and H2O2 and malondialdehyde contents. Additionally, the ATP synthase β subunit content was increased by exogenous hormone application. Based on these results, we conclude that exogenous EBR can elicit synergism between the antioxidant enzyme systems and the ATP synthase β subunit so that scavenging of reactive oxygen species becomes more efficient. These activities enable plants to cope better under combined low temperature and poor light stresses.

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.

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

Survival and mutant production induced by mutagenic agents in Metarhizium anisopliae Sobrevivência e obtenção de mutantes induzidos por agentes mutagênicos em Metarhizium anisopliae

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V. Kava - Cordeiro

1995-12-01

Full Text Available A wild strain of Metarhizium anisopliae, an entomopathogenic fungus, was submitted to three mutagenic agents: gamma radiation, ultraviolet light and nitrous acid. Survival curves were obtained and mutants were selected using different mutagenic doses which gave 1 to 5% survival. Morphological and auxotrophic mutants were isolated. Morphological mutants were grouped in a class with yellow conidia and other with pale vinaceous conidia as opposed to the green wild type conidia. Auxotrophic mutants had requirements for vitamin and aminoacid biosynthesis. More than 58% of the total auxotrophk mutants required proline/aipnine. Gamma radiation showed to be the most efficient mutagenic agent giving 0.2% of auxotrophk mutants followed by ultraviolet light (0.12% and nitrous acid (0.06%.The conidial colour and auxotrophk mutants isolated until now from M. anisopliae were reviewed.Uma linhagem selvagem do fungo entomopatogênico Metarhizium anisopliae foi submetida à ação de três agentes mutagênicos: radiação gama, luz ultravioleta e ácido nitroso. Curvas de sobrevivência foram obtidas para cada mutagênicos utilizado e mutantes foram selecionados a partir de doses dos mutagênicos que proporcionassem de 1 a 5% de sobrevivência. Mutantes morfológicos para a coloração de conídios e mutantes auxotróficos foram isolados. Mutantes para coloração de conidios foram agrupados em duas classes, uma com conídios amarelos e outra com conídios vinho pálido. Os mutantes auxotróficos obtidos foram deficientes para aminoácidos e vitaminas e mais de 58% deles eram auxotróficos para prolina/argmina. Radiação gama foi o mutagênico mais eficiente com uma porcentagem de obtenção de mulantes auxotróficos de aproximadamente 0,2%, seguido pela luz ultravioleta (0.12% e pelo ácido nitroso (0.06%.Os mulantes morfológicos e auxotróficos obtidos até o momento em Metarhizium anisopliae foram revistos.

Study on the early and late mutants of radiation induced rice

International Nuclear Information System (INIS)

Yang Hefeng; Chen Xiulan; He Zhentian; Gu Shiliang; Xu Chenwu

1990-12-01

After three years of consecutive experiments for the irradiated M 2 generations of 53 different varieties of rice, the following results have been obtained: (1) The average of early mutant plant rate is 1.4%. The rate in the early-maturing varieties is lower than that in the late-maturing varieties. It is in proportion to the length of growing period of these varieties tested. The shortened days of growing period of early mutants are 3 to 32 days (the average was 9.5 days), and it is increasing as the growing period increases. (2) In the irradiated M 2 generation of same variety, the early mutants and late mutants could be simultaneously happened, but the rate of the late mutants is 2.67%, which is higher than the rate of early mutants (1.39%). The shortened and prolonged days of growing period are 11.5 and 10.5 days respectively. These early and late mutants have some changes, both good and bad, in agronomical traits such as plant height, weight per kilo-grains and grains number per tassel. In some extent these changes are significant

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)

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

Genetic analysis of plant height in induced mutants of aromatic rice

International Nuclear Information System (INIS)

Kole, P.C.

2005-01-01

Inheritance of plant height in five gamma-ray induced mutants of aromatic rice cultivar Gobindabhog was studied through 6 x 6 diallel cross and segregation analyses. Diallel analysis revealed presence of additive and non-additive gene action with the preponderance of the latter. Proportion of dominant and recessive alleles was distributed unequally among the parents. The direction of dominance was towards tallness. The number of groups of genes was found to be three. The segregation analysis indicated the role of a single major recessive gene for height reduction in three mutants and, in another mutant, a single major recessive gene with negative modifiers. The other semi-dwarf mutant had two major recessive genes with almost equal effect in height reduction. The mutant allele(s) of the latter two mutants were non-allelic to sd sub(1) gene, which could be used as an alternative source of Dee Gee Woo Gen to widen the genetic diversity in semi-dwarfism [it

Improved Medium for Selecting Nitrate-Nonutilizing (nit) Mutants of Verticillium dahliae.

Science.gov (United States)

Korolev, N; Katan, T

1997-10-01

ABSTRACT Nitrate-nonutilizing (nit) mutants are commonly used to determine vegetative compatibility between isolates of Verticillium dahliae by complementation (heterokaryon) testing. These mutants emerge spontaneously as chlorate-resistant sectors growing out of partially restricted, wild-type colonies on chlorate-amended media. The commonly used chlorate media are based on minimal medium (MMC) or cornmeal agar (CMC), amended with potassium chlorate. nit mutants recovered on these media constituted 10 to 36%(on MMC) and 25 to 45%(on CMC) of the apparently resistant sectors. An improved water agar chlorate medium (WAC) is described that is more effective for selecting chlorate-resistant nit mutants. WAC medium consists of agar (2%), glucose (0.02%), and potassium chlorate (2 to 5%). On WAC, growth of most V. dahliae isolates was strongly inhibited, and 66 to 100%(average >80%) of the chlorate-resistant sectors formed were nit mutants. Most mutants were characterized as nit1, and about 6% as NitM.

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...

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)

Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.

Science.gov (United States)

Dong, Juan; Gasmalla, Mohammed A A; Zhao, Wei; Sun, Jingtao; Liu, Wenyu; Wang, Mingming; Han, Liang; Yang, Ruijin

2017-09-01

A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

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.

Molecular analysis of mutant and wild type alcohol dehydrogenase alleles from Drosophila

International Nuclear Information System (INIS)

Batzer, M.A.

1988-01-01

Wild type alcohol dehydrogenase polypeptides (ADH) from Drosophila melanogaster transformants were examined using western blots and polyclonal antiserum specific for Drosophila melanogaster ADH. Mutants induced in Drosophila spermatozoa at the alcohol dehydrogenase (Adh) locus using X-rays, 1-ethyl-1-nitrosourea (ENU) or ethyl methanesulfonate (EMS) were characterized using genetic complementation tests, western blots, Southern blots, northern blots and enzymatic amplification of the Adh locus. Genetic complementation tests showed that 22/30 X-ray-induced mutants, and 3/13 ENU and EMS induced mutants were multi-locus deficiencies. Western blot analysis of the intragenic mutations showed that 4/7 X-ray-induced mutants produced detectable polypeptides, one of which was normal in molecular weight and charge. In contrast 8/10 intragenic ENU and EMS induced mutants produced normal polypeptides. Southern blot analysis showed that 5/7 intragenic X-ray induced mutants and all 10 of the intragenic ENU and EMS induced mutants were normal with respect to the alleles they were derived from

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.

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

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)

Deletion of the distal COOH-terminus of the A2B adenosine receptor switches internalization to an arrestin- and clathrin-independent pathway and inhibits recycling.

Science.gov (United States)

Mundell, S J; Matharu, A-L; Nisar, S; Palmer, T M; Benovic, J L; Kelly, E

2010-02-01

We have investigated the effect of deletions of a postsynaptic density, disc large and zo-1 protein (PDZ) motif at the end of the COOH-terminus of the rat A(2B) adenosine receptor on intracellular trafficking following long-term exposure to the agonist 5'-(N-ethylcarboxamido)-adenosine. The trafficking of the wild type A(2B) adenosine receptor and deletion mutants expressed in Chinese hamster ovary cells was studied using an enzyme-linked immunosorbent assay in combination with immunofluorescence microscopy. The wild type A(2B) adenosine receptor and deletion mutants were all extensively internalized following prolonged treatment with NECA. The intracellular compartment through which the Gln(325)-stop receptor mutant, which lacks the Type II PDZ motif found in the wild type receptor initially trafficked was not the same as the wild type receptor. Expression of dominant negative mutants of arrestin-2, dynamin or Eps-15 inhibited internalization of wild type and Leu(330)-stop receptors, whereas only dominant negative mutant dynamin inhibited agonist-induced internalization of Gln(325)-stop, Ser(326)-stop and Phe(328)-stop receptors. Following internalization, the wild type A(2B) adenosine receptor recycled rapidly to the cell surface, whereas the Gln(325)-stop receptor did not recycle. Deletion of the COOH-terminus of the A(2B) adenosine receptor beyond Leu(330) switches internalization from an arrestin- and clathrin-dependent pathway to one that is dynamin dependent but arrestin and clathrin independent. The presence of a Type II PDZ motif appears to be essential for arrestin- and clathrin-dependent internalization, as well as recycling of the A(2B) adenosine receptor following prolonged agonist addition.

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.

High lysine and high yielding mutants in wheat (Triticum aestivum) L

International Nuclear Information System (INIS)

Mohammad, T.; Mahmood, F.; Ahmad, A.; Sattar, A.; Khan, I.

1988-01-01

The dry seeds of the variety Lu-26 were irradiated with 20 krad of gamma rays. In M 2 about 300 mutant plants were selected for short stature, rust resistance and other desirable traits. As a result of further selection, in M 6 , eight superior lines were finally identified. The agronomic characteristics of these mutants, the parent variety (Lu-26) and a standard check variety (Pak-81) are shown. The selected mutants and commercially grown cultivars (Lu-26 and Pak-81) were studied for total protein content and amino acid pattern. The mutants WM-89-1, WM-6-17 and WM-81-2 showing high yield also contained comparatively high amounts of methionine and lysine. The lysine contents were 565, 410, and 370 mg/100g in the mutants WM-89-1, WM-6-17 and WM-81-2, respectively against a range value of 210-370 mg/100g in other mutants and 250-320 in the commercial cultivars. The mutant WM-81-2 was comparable to WM-56-1-5 in lysine content. The results of these experiments show a possibility of developing varieties having high yield and high amounts of essential amino acids such as lysine and methionine

Structures of the N47A and E109Q mutant proteins of pyruvoyl-dependent arginine decarboxylase from Methanococcus jannaschii

International Nuclear Information System (INIS)

Soriano, Erika V.; McCloskey, Diane E.; Kinsland, Cynthia; Pegg, Anthony E.; Ealick, Steven E.

2008-01-01

The crystal structures of two arginine decarboxylase mutant proteins provide insights into the mechanisms of pyruvoyl-group formation and the decarboxylation reaction. Pyruvoyl-dependent arginine decarboxylase (PvlArgDC) catalyzes the first step of the polyamine-biosynthetic pathway in plants and some archaebacteria. The pyruvoyl group of PvlArgDC is generated by an internal autoserinolysis reaction at an absolutely conserved serine residue in the proenzyme, resulting in two polypeptide chains. Based on the native structure of PvlArgDC from Methanococcus jannaschii, the conserved residues Asn47 and Glu109 were proposed to be involved in the decarboxylation and autoprocessing reactions. N47A and E109Q mutant proteins were prepared and the three-dimensional structure of each protein was determined at 2.0 Å resolution. The N47A and E109Q mutant proteins showed reduced decarboxylation activity compared with the wild-type PvlArgDC. These residues may also be important for the autoprocessing reaction, which utilizes a mechanism similar to that of the decarboxylation reaction

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)

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.

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.

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

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

Radiation-induced mutagenicity in repair deficient Chinese hamster ovary (CHO) mutants

International Nuclear Information System (INIS)

Tesmer, J.G.; Saunders, E.H.; Chen, D.J.

1987-01-01

To determine if there is a relationship between DNA double-strand break repair and mutagenicity the authors utilized two x-ray sensitive mutants of Chinese hamster ovary cells along with the parental line K1. The two mutant lines xrs-5 and xrs-6, which have different DSB repair capabilities, were used to determine cell killing and 6-thioguanine resistance (6TG/sup r/) mutation frequencies induced by either x-rays of α-particles, x-ray survival data indicated the two mutant lines have similar sensitivity and are 5-7 fold more sensitive than the parental line K1. The mutant lines are also sensitive to α-particles but to a lesser extent. The authors' 6TG mutation data indicated that the two mutant lines are hypermutable. When mutation frequencies were plotted against the log of survival, mutation frequency at a given survival level was greater in mutant cell population than in parental K1 cells. Their results support the notion that repair of DSB play an important role in the expression of radiation-induced cell killing and mutagenicity

Respiratory-deficient mutants of the unicellular green alga Chlamydomonas: a review.

Science.gov (United States)

Salinas, Thalia; Larosa, Véronique; Cardol, Pierre; Maréchal-Drouard, Laurence; Remacle, Claire

2014-05-01

Genetic manipulation of the unicellular green alga Chlamydomonas reinhardtii is straightforward. Nuclear genes can be interrupted by insertional mutagenesis or targeted by RNA interference whereas random or site-directed mutagenesis allows the introduction of mutations in the mitochondrial genome. This, combined with a screen that easily allows discriminating respiratory-deficient mutants, makes Chlamydomonas a model system of choice to study mitochondria biology in photosynthetic organisms. Since the first description of Chlamydomonas respiratory-deficient mutants in 1977 by random mutagenesis, many other mutants affected in mitochondrial components have been characterized. These respiratory-deficient mutants increased our knowledge on function and assembly of the respiratory enzyme complexes. More recently some of these mutants allowed the study of mitochondrial gene expression processes poorly understood in Chlamydomonas. In this review, we update the data concerning the respiratory components with a special focus on the assembly factors identified on other organisms. In addition, we make an inventory of different mitochondrial respiratory mutants that are inactivated either on mitochondrial or nuclear genes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

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)

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)

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.

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.

Guidelines for the naming of genes, gene products, and mutants in the opportunistic protists.

Science.gov (United States)

Limper, Andrew H; Weiss, Louis M

2011-01-01

The opportunistic protists encompass a wide diversity of organisms including Pneumocystis, Toxoplasma, cryptosporidia, microsporidia, and related genera. Recent advances in the molecular biology and cellular biochemistry of these organisms have led to the identification of an ever growing numbers of key genes and their cognate proteins. Until now, these molecules have not been designated using any consistent nomenclature system, leading to considerable confusion. The participants of the 11th International Workshop on Opportunistic Protists met on August 3, 2010 to reach consensus of a nomenclature system for genes, gene products, and mutants in the opportunistic protists. The following summary reports the consensus agreement to move toward a unified nomenclature system for these organisms. The system is adapted from that used for Saccharomyces cerevisiae. © 2011 The Author(s). Journal of Eukaryotic Microbiology © 2011 International Society of Protistologists.

Methylammonium-resistant mutants of Nicotiana plumbaginifolia are affected in nitrate transport.

Science.gov (United States)

Godon, C; Krapp, A; Leydecker, M T; Daniel-Vedele, F; Caboche, M

1996-02-25

This work reports the isolation and preliminary characterization of Nicotiana plumbaginifolia mutants resistant to methylammonium. Nicotiana plumbaginifolia plants cannot grow on low levels of nitrate in the presence of methylammonium. Methylammonium is not used as a nitrogen source, although it can be efficiently taken up by Nicotiana plumbaginifolia cells and converted into methylglutamine, an analog of glutamine. Glutamine is known to repress the expression of the enzymes that mediate the first two steps in the nitrate assimilatory pathway, nitrate reductase (NR) and nitrite reductase (NiR). Methylammonium has therefore been used, in combination with low concentrations of nitrate, as a selective agent in order to screen for mutants in which the nitrate pathway is de-repressed. Eleven semi-dominant mutants, all belonging to the same complementation group, were identified. The mutant showing the highest resistance to methylammonium was not affected either in the utilization of ammonium, accumulation of methylammonium or in glutamine synthase activity. A series of experiments showed that utilization of nitrite by the wild-type and the mutant was comparable, in the presence or the absence of methylammonium, thus suggesting that the mutation specifically affected nitrate transport or reduction. Although NR mRNA levels were less repressed by methylammonium treatment of the wild-type than the mutant, NR activities of the mutant remained comparable with or without methylammonium, leading to the hypothesis that modified expression of NR is probably not responsible for resistance to methylammonium. Methylammonium inhibited nitrate uptake in the wild-type but had only a limited effect in the mutant. The implications of these results are discussed.

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.)

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.

Bioefficacy, residue dynamics and safety assessment of the combination fungicide trifloxystrobin 25% + tebuconazole 50%-75 WG in managing early blight of tomato (Lycopersicon esculentum Mill.).

Science.gov (United States)

Saha, Sujoy; Purath, Ahammed Shabeer Thekkum; Jadhav, Manjusha R; Loganathan, M; Banerjee, Kaushik; Rai, A B

2014-01-01

This paper reports the in vitro and in vivo bioefficacy of a combination fungicide trifloxystrobin (25%) + tebuconazole (50%) against early blight disease of tomato (Lycopersicon esculentum Mill.) caused by Alternaria solani and their corresponding pre-harvest intervals (PHI) with reference to the maximum residue limits (European Union). Bioefficacy of the test fungicide combination revealed that in vitro conditions manifested the best control (75.1%) at 350 mg kg(-1) against 76.2% control under field conditions. A sample preparation method based on ethyl acetate extraction and estimation by LC-MS multiple reaction monitoring (MRM) was validated in tomato fruits at 0.01 mg/kg and dissipation studies were conducted in field at single and double doses. The residues of both the compounds on all the sampling days were below the European Union maximum residue limits (EU-MRLs) and the maximum permissible intakes (MPIs) were calculated on the basis of prescribed acceptable daily intake (ADI). The combined bioefficacy and residue dynamics information will support label-claim of this fungicide combination for the management of early blight in tomato.

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.

Genetic and agronomic evaluation of induced semi-dwarf mutants of rice

International Nuclear Information System (INIS)

Rutger, J.N.

1984-01-01

Induced semi-dwarf mutants have played an important role in California's rapid shift from nearly all tall rice varieties in 1978 to nearly all semi-dwarf varieties at present. In 1981 over half of the California rice area was planted with semi-dwarf varieties carrying the induced mutant semi-dwarfing gene sd 1 , while much of the other half was planted to a variety deriving its semi-dwarfism from IR8. The sd 1 mutant is allelic to the major semi-dwarfing gene in DGWG and IR8. Current objectives are to determine the inheritance of new semi-dwarf mutants, including allelism tests with sd 1 , and to evaluate the agronomic potential of nonallelic sources and of double-dwarfs. To date semi-dwarf mutants from 10 varieties have been partially or completely evaluated. At least three nonallelic semi-dwarfing genes, sd 1 , sd 2 , and sd 4 , have been described. Rather than attempt to determine all possible allelic relationships of new mutants, crosses are being made only to the reference sd 1 source, since sd 1 , still seems to be the most productive semi-dwarfing gene source. However, nonallelic semi-dwarf mutants in the varieties M5 and Labelle may be useful if genetic vulnerability from widespread usage of the sd 1 source becomes a problem. (author)

Induction of mutants in Durum Wheat by hybridization and irradiation techniques

International Nuclear Information System (INIS)

Al Ubaidi, M.O.; Ibrahim, I.F.

2001-01-01

This investigation presents a breeding program for induction and development a new genotypes of durum wheat, resistant to lodging with high yield, by irradiated seeds (F2) of durum wheat hybrid's (Sin Al-jemal X Izraa, Sin Al-Jemal X Cocorat and Izraa X Cocorat) with gamma rays 100 Gy dose. This program involves: Induction of variability, selection, evaluation of the best mutants at three different locations, Twaitha(Baghdad), Latifya (Babylon) and Swari (Kutt), for the period 1990-1999. Results revealed that the mutants ( Si X Iz-7, Si X Iz-22, Si X Co-43, Si X Co-48, Si X Co-50, Si X Co- 87, Iz X Co-95 and Iz X Co-105) showed resistance to lodging with a significant reduction in plant heigth, but mutant Si X Iz-22 surpassed the other mutants and it is origin in lodging resistance and reduction in plant heigth (84.8, 81.9 and 86.3 cm) at Twaitha, Latifya and Babylon respectively in M7 and M8 generations. Also there were a significant differences between the mutants and their origin in yield and yield components during the two successive generations, on the other hand mutant Iz X Co-105 surpassed the other mutants in spikes/m2 ( 278.8, 263.3 and 289) and grain yield (4950, 4820 and 5320 kg/ha) in the testing locations respectively

Structure and expression of cytochrome f in an Oenothera plastome mutant.

Science.gov (United States)

Johnson, E M; Sears, B B

1990-06-01

The chloroplast mutant pm7 is one of a number of mutants derived from the plastome mutator (pm) line of Oenothera hookeri, strain Johansen. Immunoblotting showed that this mutant accumulates a protein that is cross-antigenic with cytochrome f, but five kilodaltons larger than the mature wild-type protein. Since cytochrome f is known to be translated on plastid ribosomes as a precursor with an amino-terminal extension, it is proposed that the unprocessed cytochrome f precursor accumulates in pm7. In addition to this precursor-sized cytochrome f protein, some mature-sized cytochrome f was also found in the mutant plastids. The pm7 mutation is inherited in a non-Mendelian fashion; but no alterations in chloroplast DNA restriction patterns, or differences in DNA sequence in the region encoding cytochrome f, were found in a comparison of the wild-type and pm7 chloroplast DNAs. Although the mutant was capable of synthesizing heme, no covalently-bound heme, normally found associated with mature, functional, cytochrome f was detected in the mutant at sizes expected for the presumed precursor, or for mature cytochrome f. These results indicate that the aberrant accumulation of a precursor-sized cytochrome f in pm7 is not due to a lesion directly in the plastid gene encoding cytochrome f, petA, or to a deficiency in the ability of the mutant plastids to synthesize or accumulate heme.

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.

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

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

Heterozygous inactivation of tsc2 enhances tumorigenesis in p53 mutant zebrafish

Directory of Open Access Journals (Sweden)

Seok-Hyung Kim

2013-07-01

Tuberous sclerosis complex (TSC is a multi-organ disorder caused by mutations of the TSC1 or TSC2 genes. A key function of these genes is to inhibit mTORC1 (mechanistic target of rapamycin complex 1 kinase signaling. Cells deficient for TSC1 or TSC2 have increased mTORC1 signaling and give rise to benign tumors, although, as a rule, true malignancies are rarely seen. In contrast, other disorders with increased mTOR signaling typically have overt malignancies. A better understanding of genetic mechanisms that govern the transformation of benign cells to malignant ones is crucial to understand cancer pathogenesis. We generated a zebrafish model of TSC and cancer progression by placing a heterozygous mutation of the tsc2 gene in a p53 mutant background. Unlike tsc2 heterozygous mutant zebrafish, which never exhibited cancers, compound tsc2;p53 mutants had malignant tumors in multiple organs. Tumorigenesis was enhanced compared with p53 mutant zebrafish. p53 mutants also had increased mTORC1 signaling that was further enhanced in tsc2;p53 compound mutants. We found increased expression of Hif1-α, Hif2-α and Vegf-c in tsc2;p53 compound mutant zebrafish compared with p53 mutant zebrafish. Expression of these proteins probably underlies the increased angiogenesis seen in compound mutant zebrafish compared with p53 mutants and might further drive cancer progression. Treatment of p53 and compound mutant zebrafish with the mTORC1 inhibitor rapamycin caused rapid shrinkage of tumor size and decreased caliber of tumor-associated blood vessels. This is the first report using an animal model to show interactions between tsc2, mTORC1 and p53 during tumorigenesis. These results might explain why individuals with TSC rarely have malignant tumors, but also suggest that cancer arising in individuals without TSC might be influenced by the status of TSC1 and/or TSC2 mutations and be potentially treatable with mTORC1 inhibitors.

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)

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

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

Construction of a large-scale Burkholderia cenocepacia J2315 transposon mutant library

Science.gov (United States)

Wong, Yee-Chin; Pain, Arnab; Nathan, Sheila

2014-09-01

Burkholderia cenocepacia, a pathogenic member of the Burkholderia cepacia complex (Bcc), has emerged as a significant threat towards cystic fibrosis patients, where infection often leads to the fatal clinical manifestation known as cepacia syndrome. Many studies have investigated the pathogenicity of B. cenocepacia as well as its ability to become highly resistant towards many of the antibiotics currently in use. In addition, studies have also been undertaken to understand the pathogen's capacity to adapt and survive in a broad range of environments. Transposon based mutagenesis has been widely used in creating insertional knock-out mutants and coupled with recent advances in sequencing technology, robust tools to study gene function in a genome-wide manner have been developed based on the assembly of saturated transposon mutant libraries. In this study, we describe the construction of a large-scale library of B. cenocepacia transposon mutants. To create transposon mutants of B. cenocepacia strain J2315, electrocompetent bacteria were electrotransformed with the EZ-Tn5 transposome. Tetracyline resistant colonies were harvested off selective agar and pooled. Mutants were generated in multiple batches with each batch consisting of ˜20,000 to 40,000 mutants. Transposon insertion was validated by PCR amplification of the transposon region. In conclusion, a saturated B. cenocepacia J2315 transposon mutant library with an estimated total number of 500,000 mutants was successfully constructed. This mutant library can now be further exploited as a genetic tool to assess the function of every gene in the genome, facilitating the discovery of genes important for bacterial survival and adaptation, as well as virulence.

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...

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

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.)

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)

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.

Mutant form C115H of Clostridium sporogenes methionine γ-lyase efficiently cleaves S-Alk(en)yl-l-cysteine sulfoxides to antibacterial thiosulfinates.

Science.gov (United States)

Kulikova, Vitalia V; Anufrieva, Natalya V; Revtovich, Svetlana V; Chernov, Alexander S; Telegin, Georgii B; Morozova, Elena A; Demidkina, Tatyana V

2016-10-01

Pyridoxal 5'-phosphate-dependent methionine γ-lyase (MGL) catalyzes the β-elimination reaction of S-alk(en)yl-l-cysteine sulfoxides to thiosulfinates, which possess antimicrobial activity. Partial inactivation of the enzyme in the course of the reaction occurs due to oxidation of active site cysteine 115 conserved in bacterial MGLs. In this work, the C115H mutant form of Clostridium sporogenes MGL was prepared and the steady-state kinetic parameters of the enzyme were determined. The substitution results in an increase in the catalytic efficiency of the mutant form towards S-substituted l-cysteine sulfoxides compared to the wild type enzyme. We used a sulfoxide/enzyme system to generate antibacterial activity in situ. Two-component systems composed of the mutant enzyme and three S-substituted l-cysteine sulfoxides were demonstrated to be effective against Gram-positive and Gram-negative bacteria and three clinical isolates from mice. © 2016 IUBMB Life, 68(10):830-835, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

Selecting rice mutants with good agronomic performance under conditions of low water supplies

International Nuclear Information System (INIS)

González Cepero, María C.; Martínez Romero, Anirebis

2016-01-01

The present work is part of the researches that are carried out in the Regional Project of the International Organization of Atomic Energy (IAEA) Mutation Breeding of Alimentary Cultivations in Latin America where Cuba participates. The aim of this project is to obtain new rice varieties tolerant to drought using nuclear techniques, for that which is necessary to determine indicators for early selection of tolerant genotypes and to identify somaclones and/or mutants of good behavior under low water supply. For this study were used, 13 mutants obtained in the National Institute of Agricultural Sciences (INCA) as well as the rice varieties Amistad-82 and J-104. The response to the hydric stress under field conditions was determined, using irrigation during the first 45 days, interrupting later for the plant cycle, were determined: I) the height of the plant, II) weigh of 1000 grains, III) length of panicle, IV) number of full grains, V) vain grains, VI) number of panicle for lineal meter and VII) yield for square meter. Likewise in vitro the answers to the drought with a concentration of 5 g L-1 of PEG-6000 to simulate the hydric stress and the Relative Tolerance Index of root and of height were evaluated. Some indicators for early selection of tolerant genotypes starting from the existent correlation among the characters evaluated in the field in vivo and in vitro were also determined. The INCA genotypes LP-10 and 8552 showed a better behavior under conditions of low supplies of water and INCA LP 16 genotypes and mutant 8553 were the most susceptible because they could not panicular under the same conditions. (author)

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)

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

Science.gov (United States)

Adnan, Humaira; Zhang, Zhenbo; Park, Hyun-Joo; Tailor, Chetankumar; Che, Clare; Kamani, Mustafa; Spitalny, George; Binnington, Beth; Lingwood, Clifford

2016-01-01

Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon), to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin) containing genetically inactivated (± an N-terminal polyleucine tail) A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF) mutant (5-10x), F508delCFTR Golgi maturation (glucocerobrosidase (GCC) in N370SGCC Gaucher Disease fibroblasts (3x), another ERAD-exacerbated misfiling disease. We identify a new, potentially benign approach to the treatment of certain genetic protein misfolding diseases.

Characterization of a bacteriophage T4 mutant lacking DNA-dependent ATPase

International Nuclear Information System (INIS)

Behme, M.T.; Ebisuzaki, K.

1975-01-01

A DNA-dependent ATPase has previously been purified from bacteriophage T4-infected Escherichia coli. A mutant phage strain lacking this enzyme has been isolated and characterized. Although the mutant strain produced no detectable DNA-dependent ATPase, growth properties were not affected. Burst sizes were similar for the mutant phage and T4D in polAl, recB, recC, uvrA, uvrB, uvrC, and various DNA-negative E. coli. UV sensitivity and genetic recombination were normal in a variety of E. coli hosts. Mapping data indicate that the genetic locus controlling the mutant occurs near gene 56. The nonessential nature of this gene is discussed

Radiation-sensitive mutant of hypertoxinogenic strain 569B of Vibro cholerae

International Nuclear Information System (INIS)

Das, G.; Das, J.

1983-01-01

A radiation-sensitive mutant of the hypertoxinogenic strain 569B of Vibrio cholerae was isolated and characterized. The mutant, designated V. cholerae 569Bsub(s), lacks both excision- and medium-dependent dark-repair mechanisms of UV-induced DNA damage while retaining the wild-type photoreactivating capability. Analysis of the UV-irradiated cell DNA by velocity sedimentation in alkaline sucrose gradient suggests that UV-induced pyrimidine dimers may not be incised in these cells. In contrast to the wild-type cells, the mutant cell DNA was degraded after treatment with nalidixic acid. The mutant cells failed to produce any detectable amount of cholera toxin as measured by ileal-loop assay. (orig.)

Therapeutic Targeting of Spliceosomal-Mutant Acquired Bone Marrow Failure Disorders

Science.gov (United States)

2017-05-01

spliceosomal mutant cells . This effort has also highlighted a requirement for innate immune signaling in SF3B1-mutant MDS and has implicated a few specific...relative to single-mutant cells (Figure 5A). As innate immune signaling has been implicated in MDS pathogenesis (Basiorka et al., 2016; Fang et al...Sato et al., 2005; Tang et al., 2008; Vink et al., 2013; Xin et al., 2017). Here, we observed that SF3B1K700E/+ human lymphoid leukemia cells (NALM-6

Negative effects of fluoranthene on the ecophysiology of tomato plants (Lycopersicon esculentum Mill) Fluoranthene mists negatively affected tomato plants.

Science.gov (United States)

Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

2010-02-01

Cherry tomato plants (Lycopersicon esculentum Mill) were sprayed with fluoranthene and mixture of fluoranthene and mannitol solutions for 30d. The exposure was carried out in growth chambers in field conditions, and the air was filtered through charcoal filters to remove atmospheric contaminants. Plants were sprayed with 10microM fluoranthene as mist until they reached the fruiting stage, and the eco-physiological parameters were measured to determine the effects of the treatments. We measured CO(2) uptake and water vapour exchange, chlorophyll fluorescence, leaf pigment contents, visual symptoms and biomass allocation. Fluoranthene which was deposited as mist onto leaves negatively affected both growth and the quality of tomato plants, while other treatments did not. The photosynthetic rate measured at saturated irradiance was approximately 37% lower in fluoranthene-treated plants compared with the control group. Other variables, such as stomata conductance, the photochemical efficiency of PSII in the dark, Chl a, Chl b, and the total chlorophyll contents of the tomato leaves were significantly reduced in the fluoranthene-treated plants. Tomato plants treated with fluoranthene showed severe visible injury symptoms on the foliage during the exposure period. Mannitol (a reactive oxygen scavenger) mitigated effects of fluoranthene; thus, reactive oxygen species generated through fluoranthene may be responsible for the damaged tomato plants. It is possible for fluoranthene to decrease the aesthetic and hence the economic value of this valuable crop plant. 2009 Elsevier Ltd. All rights reserved.

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

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 ...

Studies on induced partially resistant mutants of barley against powdery mildew

International Nuclear Information System (INIS)

Roebbelen, G.; Abdel-Hafez, A.G.; Reinhold, M.; Kwon, H.J.; Neuhaus-Steinmetz, J.P.; Heun, M.

1983-01-01

After mutagenic seed treatment of three partially resistant cultivars of spring barley with EMS and NaN 3 , 45 mutants in a first and 16 in a second experiment were selected in the M 2 -M 4 generations. The screening was done alternatively under natural infection in the field or controlled infection with a single pathotype in the greenhouse. These mutants exhibited a higher resistance and a higher susceptibility, respectively, than the initial cultivars Asse, Bomi and Vada. Some mutants expressed their altered resistance behaviour particularly during certain stages of development. High-level resistance was conditioned by mutation in the ml-o locus in three cases. For several Bomi mutants pathotype specificity with and without reversed ranking was proven as well as pathotype non-specificity in comparison with the reaction of the original cultivar. In 14 cases studied the inheritance of the involved mutants was monogenic recessive. The laevigatum locus responsible for the intermediate mildew resistance of Bomi was not affected by the mutations. Detection of groups of allelic mutants showed that there are at least two regions in the barley genome in which mutations for mildew resistance can occur rather frequently. In total, the past ten years of this mutation research have given convincing evidence that the strategies of mutant screening applied have yielded promising new material both for breeding and for progress in basic understanding of host-pathogen interactions. (author)

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)

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

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 ...

The behaviour of Bombus impatiens (Apidae, Bombini on tomato (Lycopersicon esculentum Mill., Solanaceae flowers: pollination and reward perception

Directory of Open Access Journals (Sweden)

Peter Kevan

2013-10-01

Full Text Available The foraging behaviour of pollinators can influence their efficiency in pollinating certain plant species. Improving our understanding of this behaviour can contribute to an improvement of management techniques to avoid pollination deficits. We investigated the relationship between the number of visits of bumble bees (Bombus impatiensto tomato flowers (Lycopersicon esculentum and two variables related to the quality of the resulting fruits (weight, number of seeds, as well as the relationship between foragers’ thoracic weights, physical characteristics of thoracic vibrations (main frequency, velocity amplitude, amount of pollen removed from flowers, and the quality-related variables. In addition, we studied the capability of foragers to assess the availability of pollen in flowers. Tomato weight and seed number did not increase with the number of bee visits, neither were they correlated with the foragers’ thorax weight. Thorax weight also did not correlate with the amount of pollen removed from the flowers nor with the physical characteristics of vibration. Vibration characteristics did not change in response to the amount of pollen available on tomato flowers. Instead, foragers adjusted the time spent visiting the flowers, spending fewer time on flowers from which some pollen had already been removed on previous visits. The quantity and the production-related variables of tomatoes are not dependent on the number of bee visits (usually one visit suffices for full pollination; bigger foragers are not more efficient in pollinating tomato flowers than smaller ones; and B. impatiens foragers are capable of evaluating the amount of pollen on a flower while foraging and during pollination.

A higher yielding mutant of black gram with improved nodule formation

International Nuclear Information System (INIS)

Singh, R.K.; Raghuvanshi, S.S.

1987-01-01

Dry seeds of black gram (Vigna mungo (L) Hopper) var. T 9 with 12.2% moisture content were irradiated at 10, 20 and 30 krad of gamma rays. This was followed by combined treatment of one set in each dose with freshly prepared 0. 25% EMS in phosphate buffer at 7.0 pH at 30± deg. C for 6 hours. In M 2 population of 20 krad two mutants with pentafoliate instead of trifoliate leaves were found. This character was true breeding in M 3 M 6 generation. Crosses revealed monogenic recessive inheritance of this character. The proposed gene symbol is p5. This mutant has normal maturity period and the plant height is the same as T 9 (ca. 50 cm). Preliminary yield trials indicate superiority of the mutant line over control. The mutant line also shows a significant improvement in number and weight of root nodules, potentially improving green manuring value. Improvement of root nodulation in mungbean mutants was reported before by others

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.

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.

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

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...

Increased spontaneous mitotic segregation in MMS-sensitive mutants of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, S.; Prakash, L.

1977-01-01

Methyl methanesulfonate (MMS)-sensitive mutants of Saccharomyces cerevisiae belonging to four different complementation groups, when homozygous, increase the rate of spontaneous mitotic segregation to canavanine resistance from heterozygous sensitive (can/sup r//+) diploids by 13- to 170-fold. The mms8-1 mutant is MMS and x-ray sensitive and increases the rate of spontaneous mitotic segregation 170-fold. The mms9-1 and mms13-1 mutants are sensitive to x rays and uv, respectively, in addition to MMS, and increase the rate of spontaneous mitotic segregation by 13-fold and 85-fold, respectively. The mutant mms21-1 is sensitive to MMS, x rays and uv and increases the rate of spontaneous mitotic segregation 23-fold

Identification of dominant male sterile mutants in rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Zhu Xudong; Rutger, J.N.

2000-01-01

Genetic male sterile mutants 1783 and 1789 were selected from US variety Orion and Kaybonnet seeds treated by gamma irradiation. Investigation of fertility characterization of pollen and spikelets of these mutants were made by progeny tests in 1783 M 7 and 1789 M 6 generations. The results showed that genetic male sterile mutants 1783 and 1789 with the fertility segregating of 1 sterile: 1 fertile were controlled by a single dominant gene. The pollen staining of mutants characterized partial sterility. Open-pollinated seed set was about 30% and bagged seed set was only 0.3%-3.5%. It is concluded that dominant genetic male sterile is a useful tool in improvement of population for rice breeding

Root and Nodulation Phenotypes of the Ethylene-Insensitive Sickle Mutant of Medicago truncatula

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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.

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

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

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.

Internal Dynamics and Ionization States of the Macrophage Migration Inhibitory Factor: Comparison Between Wild-Type and Mutant Forms

International Nuclear Information System (INIS)

Soares, T A.; Lins, R D.; Straatsma, TP; Briggs, J M.

2002-01-01

The macrophage migration inhibitory factor (MIF) is a cytokine which shares a common structural architecture and catalytic strategy with three isomerases: 4-oxalocrotonate tautomerase, 5-carboxymethyl-2-hydroxymuconate isomerase and D-dopachrome tautomerase. A highly conserved N-terminal proline acts as a base/acid during the proton transfer reaction catalyzed by these enzymes. Such unusual catalytic strategy appears to be possible only due to the N-terminal proline pKa be shifted to 5.0-6.0 units. Mutations of this residue result in a significant decrease of the catalytic activity of MIF. Two hypotheses have been proposed to explain the catalytic inefficiency of MIF: the lower basicity of primary amines with regard to secondary ones and the increased flexibility resulting from the replacement of a proline by residues like glycine. To investigate that, we have performed molecular dynamics simulations of MIF-wt and its mutant P1G as well as calculated the protonation properties of sever al mutant forms. It has been found that the N-terminal glycine does not show larger fluctuations compared to proline, but the former residue is more exposed to the solvent throughout the simulations. The apparent pKa of these residues displays very little change (as expected from the structural rigidity of MIF) and is not significantly affected by the surrounding ionizable residues. Instead, the hydrophobic character of the active site seems to be the main factor in determining the pKa of the N-terminal residue and the catalytic efficiency of MIF

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

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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.

Behaviour of UV-sensitive mutants of Proteus mirabilis to repair incision breaks

International Nuclear Information System (INIS)

Stoerl, K.; Mund, C.

1977-01-01

In U.V.-sensitive mutants of P. mirabilis with the phenotype HCR, REC and EXR single-strand breaks appeared immediately after UV-irradiation. The behaviour of REC- and EXR-mutants was similar to the wildtype. The number of incision breaks observed by sedimentation analysis in these strains was very low. They could be joined during the excision repair process. From the ability of REC- and EXR-strains to rejoin most of the induced single-strand breaks it can be concluded that these strains have approximately the same capacity for excision repair as the wildtype. HCR-mutants of P. mirabilis produced single-strand breaks after UV-irradiation in contrast to HCR-mutants of E. coli. Therefore we suggest that HCR-mutants of P. mirabilis are not completely inhibited in the incision step. The single-strand breaks introduced in the DNA at the beginning of the repair process were not rejoined during further incubation. Experiments with toluenized cells led to the same results. The newly synthesized daughter DNA-strands of UV-irradiated HCR-mutants were of low molecular weight in comparison with those from unirradiated control cells during the repair period. This result is in agreement with the incapability of HCR-mutants to remove the pyrimidine dimers from the parental template strand. (author)

Development mutants of anabaena doliolum defective in repair of UV-damage

International Nuclear Information System (INIS)

Tiwari, D.N.; Singh, C.B.

1980-01-01

Nitrosoguanidine induced 'blue' pigment mutants of the blue-green alga anabaena doliolum were isolated. The blue-mutants on further characterization were grouped into three developmental phenotypes - (i) those forming doli-form blue-spores of heterogenous size i.e., Ad 011, (ii) those forming spheroidal cells in the stationary phase, some of which behave like spores on transfer to fresh medium i.e., Ad 012, and (iii) those showing no sporulation and conditionally producing abnormal cells in the presence of combined nitrogen only i.e., Ad 007. The former two classes of mutants showed the formation of abnormal cells irrespective of the presence or absence of combined nitrogen sources in the medium. The formation of abnormal cells in the filaments of the above mutants were distinguished by their larger size and irregular mode of division leading to true-branch formation. The comparative characterization of these mutant strains with the parental one showed sluggish growth, increased UV-sensitivity, almost unchanged photorepair capacity, a marked change in the pigment composition and relative resistance to nitrosoguanidine. Irregular cell division in both space and time in the mutant strains and their increased sensitivity to ultraviolet irradiation indicate the possible involvement of dark repair system in maintaining the precision of cell cylce in this alga. (orig.) 891 AJ/orig. 892 HIS

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

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)

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

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...

A detailed study of gerJ mutants of Bacillus subtilis.

Science.gov (United States)

Warburg, R J; Buchanan, C E; Parent, K; Halvorson, H O

1986-08-01

A total of nine gerJ mutants have now been isolated in Bacillus subtilis. All are defective in their spore germination properties, being blocked at an intermediate (phase grey) stage. The dormant spores are sensitive to heating at 90 degrees C and two of the mutants (generated by transposon insertion) produce spores sensitive at 80 degrees C. The spores of these two more extreme mutants had a visibly defective cortex when studied by electron microscopy, as did some of the other mutants. During sporulation, the acquisition of spore resistance properties and the appearance of the sporulation-specific penicillin-binding protein PBP5* were delayed. A strain probably carrying a lacZ fusion to the gerJ promoter demonstrated increased expression between t2 and t4. We propose that the gerJ locus is involved in the control of one or more sporulation-specific genes.

Rescue of glaucoma-causing mutant myocilin thermal stability by chemical chaperones

Science.gov (United States)

Burns, J. Nicole; Orwig, Susan D.; Harris, Julia L.; Watkins, J. Derrick; Vollrath, Douglas; Lieberman, Raquel L.

2010-01-01

Mutations in myocilin cause an inherited form of open angle glaucoma, a prevalent neurodegenerative disorder associated with increased intraocular pressure. Myocilin forms part of the trabecular meshwork extracellular matrix presumed to regulate intraocular pressure. Missense mutations, clustered in the olfactomedin (OLF) domain of myocilin, render the protein prone to aggregation in the endoplasmic reticulum of trabecular meshwork cells, causing cell dysfunction and death. Cellular studies have demonstrated temperature-sensitive secretion of myocilin mutants, but difficulties in expression and purification have precluded biophysical characterization of wild-type (wt) myocilin and disease-causing mutants in vitro. We have overcome these limitations by purifying wt and select glaucoma-causing mutant (D380A, I477N, I477S, K423E) forms of the OLF domain (228–504) fused to maltose binding protein (MBP) from E. coli. Monomeric fusion proteins can be isolated in solution. To determine the relative stability of wt and mutant OLF domains, we developed a fluorescence thermal stability assay without removal of MBP, and provide the first direct evidence that mutated OLF is folded but less thermally stable than wt. We tested the ability of seven chemical chaperones to stabilize mutant myocilin. Only sarcosine and trimethylamine N-oxide were capable of shifting the melting temperature of all mutants tested to near that of wt OLF. Our work lays the foundation for the identification of tailored small molecules capable of stabilizing mutant myocilin and promoting secretion to the extracellular matrix, to better control intraocular pressure and ultimately delay the onset of myocilin glaucoma. PMID:20334347

Bacillus subtilis mutants deficient in the adaptive response to simple alkylating agents

Energy Technology Data Exchange (ETDEWEB)

Morohoshi, F.; Munakata, N.

1985-03-01

Three mutant strains exhibiting hyper-sensitivity to N-methyl-N'-nitro-N-nitrosoguanidine, but not to methyl methanesulfonate, were selected by a replica method from mutagenized spores of Bacillus subtilis. All three were totally deficient in the adaptive response to N-methyl-N'-nitro-N-nitrosoguanidine with regard to both lethality and mutagenesis. The activity to destroy O/sup 6/-methylguanine residues in the methylated DNA was not elevated in the mutant cells by the pretreatment with sublethal concentrations of N-methyl-N-nitro-N-nitrosoguanidine. This deficiency corresponded to the persistance of O/sup 6/-methylguanine residues in the DNA of both control and pretreated mutant cells challenged with the drug. The lethal and mutagenic sensitivity of the mutant strains were observed only for methyl- or ethyl-nitroso compounds that are thought to be active as inducers and are also active in O-alkylation. Except for the insensitivity to methyl methanesulfonate, the phenotypes of these mutants look very similar to those of ada mutants isolated previously in Escherichia coli.

Characteristic, inheritance and breeding application of rice mutants with greenable albino leaf

International Nuclear Information System (INIS)

Fang Xiantao; Ma Hongli; Zhao Fuyuan; Zhang Qingqi; Zhang Shubiao

2009-01-01

Inheritance and main agronomic traits of photo-thermo-sensitive genic male sterile line with green-revertible albino leaf were investigated. The results indicated that the mutants might be divided into three types: albino regreening type (W2, W3, W4 and W10), albino to kelly type (W9) and abino-regreening-albino-regreening type (W1 and W7). Genetic study indicated that green-revertible albino leaf color trait of the mutants as controlled by a single recessive gene. These mutants had similar agronomic traits and fertility characteristics to the corresponding male sterile line 'Peiai 64S'. The hybrids of these mutants had similar characteristics with original-hybrids in plant type, developing of tillers and plant height. The yield components of the mutant hybrids were different depending on different mutants. The yield potential of hybrids of W1, W2 and W3 were similar to the original-hybrid. The results also indicated that W1, W2 and W3 had breeding application value. (authors)

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

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.

Promissory rice mutants (Oryza sativa L.) obtained by Gamma Rays induction in Peru

International Nuclear Information System (INIS)

Heros, E.; Gomez, L.

2015-01-01

To improve the available rice cultivars in Peru under irrigated conditions, it was tried the rice seed Amazonas and Capirona, cultivars adapted to irrigated conditions in highland jungle, both characterized for late maturity (140-150 days). The doses were: 150-250-350 Gy that induced mutants with different characteristics to the original cultivar like: early maturity, shorter, high yield and milling quality. In Amazonas cultivar were selected 72 mutants of the M 2 generation with agronomy value and continue in evaluation only the mutant (M35-20). There were applied the same doses of gamma rays with the cultivar Capirona, there is much radiosensitivity at high doses, they were selected two early mutants (MC 35-21 and MC 35-123-3) with an early life cycle days (15 days) than parental cultivar. Two mutants tolerant to salinity (12 dSm). Six mutants are still under evaluation, two of them (MC 25-23-1 and MC 35-45-4) have better yields with performances of 9.1 t ha -1 versus 6.6 t ha -1 . These mutants show lodging and shattering resistance. (Author)

Purification and characterization of mutant miniPlasmin for thrombolytic therapy

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Lin Xiaotao

2013-01-01

Full Text Available Abstract Background Previous animal studies by us and others have indicated that catheter-administered plasmin or its des-kringle derivatives may be more appropriate alternatives to plasminogen activators for treating thrombolytic diseases, since it has a very short serum half-life and therefore does not result in hemorrhaging. We have previously produced recombinant miniPlasmin (mPlasmin that was proven suitable for treating peripheral arterial occlusion in animal models. However, our previous results showed that non-specific cleavage at position K698 of mPlasmin during activation hindered the further development of this promising therapeutic candidate. In order to minimize or eliminate the non-specific cleavage problem, we performed saturation mutagenesis at the K698 position to develop a mutant form of mPlasmin for thrombolytic therapy. Methods We changed K698 to 16 other amino acids, with preferred E. coli codons. Each of these mutants were expressed in E. coli as inclusion bodies and then refolded, purified, and subsequently characterized by detailed kinetic assays/experiments/studies which identified highly active mutants devoid of non-specific cleavage. Results Activation studies indicated that at those conditions in which the wild type enzyme is cut at the non-specific position K698, the active mutants can be activated without being cleaved at this position. Conclusions From the above results, we selected two mutants, K698Q and K698N, as our lead candidates for further thrombolytic drug developments. The selected mutants are potentially better therapeutic candidates for thrombolytic therapy.

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.

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)

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)

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...

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...

Temperature-sensitive mutants of fowl plague virus: isolation and genetic characterization

International Nuclear Information System (INIS)

Almond, J.W.; McGeoch, D.; Barry, R.D.

1979-01-01

Forty-nine temperature-sensitive mutants of fowl plague virus (FPV) strain Rostock and four ts mutants of FPV-strain Dobson were isolated by utilizing two methods of plaque screening, after either spontaneous or chemically induced mutagenesis. Twenty-nine of the FPV-Rostock mutants were further characterized by genetic recombination studies and were found to fall into six high frequency recombination groups. The genome segment carrying the ts mutation in each group was identified by analyzing the gene composition of ts + recombinants generated from crosses between representatives of each group and ts mutants of FPV-Dobson. It was concluded that the six groups correspond to mutations in six different genome segments, namely, those coding for the P 1 , P 2 , P 3 , HA, NP, and NS proteins

Analysis of nutritional quality of low phytic acid mutants in maize

International Nuclear Information System (INIS)

Yuan Ming'an; Luo Hongbing; Wang Zhonghua; Chen Jinhong; Mei Shufang; Shu Xiaoli; Wu Dianxing

2008-01-01

Major nutritional quality and components of eight low phytic acid (lpa) mutants and their corresponding wild types were studied. Compared to their corresponding wild types, the content of inorganic P (Pi) was all increased several times, while the content of total P (TP) in mutants was almost the same as their wild types. The contents of crude lipid and amylose were similar, but total starch was significantly different. Crude protein in some of mutants was increased significantly. Most of amino acids were increased, and essential amino acid-Lysine was increased except mutants derived from Q319 and X178. Mineral macronutrients and micronutrients were similar. All results showed that the lpa mutation in maize could enhance the nutritional quality and bioactivities. (authors)

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

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

A higher yielding mutant of black gram with improved nodule formation

Energy Technology Data Exchange (ETDEWEB)

Singh, R K; Raghuvanshi, S S [Plant Genetic Unit, Department of Botany, University of Lucknow (India)

1987-07-01

Dry seeds of black gram (Vigna mungo (L) Hopper) var. T{sub 9} with 12.2% moisture content were irradiated at 10, 20 and 30 krad of gamma rays. This was followed by combined treatment of one set in each dose with freshly prepared 0. 25% EMS in phosphate buffer at 7.0 pH at 30{+-} deg. C for 6 hours. In M{sub 2} population of 20 krad two mutants with pentafoliate instead of trifoliate leaves were found. This character was true breeding in M{sub 3} M{sub 6} generation. Crosses revealed monogenic recessive inheritance of this character. The proposed gene symbol is p5. This mutant has normal maturity period and the plant height is the same as T{sub 9} (ca. 50 cm). Preliminary yield trials indicate superiority of the mutant line over control. The mutant line also shows a significant improvement in number and weight of root nodules, potentially improving green manuring value. Improvement of root nodulation in mungbean mutants was reported before by others.

Un Nuevo Enfoque en el Estudio de la Esporotricosis: Mutantes de Sporothrix schenckii

Directory of Open Access Journals (Sweden)

Haydee Torres-Guerrero

2012-02-01

Full Text Available Una cepa silvestre y cepas mutantes de Sporothrix schenckii, se han estudiado como un modelo experimental de los procesos de diferenciación y desarrollo que se presentan al ser invadidas las células huésped y causar la esporotricosis. Las cepas mutantes de S. schenckii fueron obtenidas por exposición a la luz ultravioleta y Nitrosoguanidina. Las mutantes morfológicas M-III y M-V fueron seleccionadas. Estas mutantes muestran una alteración colonial y un mayor desarrollo que las cepas silvestres. Además, las mutantes presentan mayor adhesión al sustrato. El análisis de componentes de la pared celular y la distribución de núcleos, indican que no existen diferencias significativas que implique un daño por la mutación. Los resultados indican que en las mutantes morfológicas existe una alteración en el patrón de crecimiento y su regulación. Son necesarios, estudios bioquímicos e inmunológicos, relacionados con la virulencia S. schenckii que puedan ser útiles en el diagnóstico y en un futuro contribuyan a medidas preventivas para la esporotricosis. A wild-type strain and mutant strain of Sporothrix schenckii were studied as an experimental model in the process of differentiation and development which occurs when the host cell is invaded causing sporotrichosis. The mutant strains of S. schenckii were obtained by exposure to ultraviolet light and Nitrosoguanidine. The morphological mutants M-III and M-V were selected. These mutants showed a colonial alteration and a higher growth rate than the wild-type strains. Moreover, the mutants showed greater adhesion to the substratum. An analysis of the components of the cell wall and the distribution of nuclei indicate that significant differences do not exist which involve damage by mutation. The results suggest that in morphological mutants there is an alteration of growth and its regulation in the host cell. Biochemical and immunological studies related to the virulence of S. schenkii are

Induction of mutagenized tomato populations for investigation on agronomic traits and mutant phenotyping

Directory of Open Access Journals (Sweden)

Rafiul Amin Laskar

2018-01-01

Full Text Available Global demand for tomato production increased tremendously due to its diverse utility in raw, cooked and processed form of food. This necessitates the continued supply of highly nutritious and better yielding improved cultivars to the producers, considering the rapid changing agro-climatic condition. In this study, induced mutant tomato populations of widely recommended tomato genotype Arka Vikas (Sel-22 were generated using chemical mutagen ethyl methane sulfonate (EMS, hydrazine hydrates (HZ and their combined treatments. In the in vitro study, a gradual reduction in germination percentage and seedling height occurred with the increasing concentrations of mutagens. Combination of EMS and HZ caused maximum biological inhibition followed by EMS and HZ treatments alone in M1 generation. The rate of survival and fertility in M1 plants of tomato was found highly affected due to mutagenic treatment, in which sensitivity toward combined treatment was found highest followed by EMS and HZ. Inspection on induced phenotypic variations in individual plants of M2 population resulted in identification and isolation of wide range of mutants with altered phenotypes. Highest mutation frequency was resulted by combined mutagens followed by the EMS and HZ treatment. Agronomic trait analyses showed intra and inter treatment variations in three quantitative traits (Plant height, fertile branch per plant and fruits per plant of M2 mutagenized population. Assessment on rate of mutant recovery in M2 population showed highest mutant recovery is possible with combination treatments and then 0.02% HZ followed by 0.02% EMS. In the present study, phenotyping of the mutants revealed that vegetative organs (‘plant size’, ‘plant habit’ and ‘leaf morphology’ was the most sensitive category (69.33% to which most of the mutant belongs, followed by ‘fruit color and size’ (20.27% and ‘germination’ (9.79%. Comparative investigation on number of mutants and

Mutant DnaAs of Escherichia coli that are refractory to negative control.

Science.gov (United States)

Chodavarapu, Sundari; Felczak, Magdalena M; Simmons, Lyle A; Murillo, Alec; Kaguni, Jon M

2013-12-01

DnaA is the initiator of DNA replication in bacteria. A mutant DnaA named DnaAcos is unusual because it is refractory to negative regulation. We developed a genetic method to isolate other mutant DnaAs that circumvent regulation to extend our understanding of mechanisms that control replication initiation. Like DnaAcos, one mutant bearing a tyrosine substitution for histidine 202 (H202Y) withstands the regulation exerted by datA, hda and dnaN (β clamp), and both DnaAcos and H202Y resist inhibition by the Hda-β clamp complex in vitro. Other mutant DnaAs carrying G79D, E244K, V303M or E445K substitutions are either only partially sensitive or refractory to inhibition by the Hda-β clamp complex in vitro but are responsive to hda expression in vivo. All mutant DnaAs remain able to interact directly with Hda. Of interest, both DnaAcos and DnaAE244K bind more avidly to Hda. These mutants, by sequestrating Hda, may limit its availability to regulate other DnaA molecules, which remain active to induce extra rounds of DNA replication. Other evidence suggests that a mutant bearing a V292M substitution hyperinitiates by escaping the effect of an unknown regulatory factor. Together, our results provide new insight into the mechanisms that regulate replication initiation in Escherichia coli.

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...

'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)

Severity of mutant phenotype in a series of chlorophyll-deficient wheat mutants depends on light intensity and the severity of the block in chlorophyll synthesis.

Science.gov (United States)

Falbel, T G; Meehl, J B; Staehelin, L A

1996-10-01

Analyses of a series of allelic chlorina mutants of wheat (Triticum aestivum L.), which have partial blocks in chlorophyll (Chl) synthesis and, therefore, a limited Chl supply, reinforce the principle that Chl is required for the stable accumulation of Chl-binding proteins and that only reaction centers accumulate when the supply of Chl is severely limited. Depending on the rate of Chl accumulation (determined by the severity of the mutation) and on the rate of turnover of Chl and its precursors (determined by the environment in which the plant is grown), the mutants each reach an equilibrium of Chl synthesis and degradation. Together these mutants generate a spectrum of phenotypes. Under the harshest conditions (high illumination), plants with moderate blocks in Chl synthesis have membranes with very little Chl and Chl-proteins and membrane stacks resembling the thylakoids of the lethal xantha mutants of barely grown at low to medium light intensities (which have more severe blocks). In contrast, when grown under low-light conditions the same plants with moderate blocks have thylakoids resembling those of the wild type. The wide range of phenotypes of Chl b-deficient mutants has historically produced more confusion than enlightenment, but incomparable growth conditions can now explain the discrepancies reported in the literature.

The Origin of Mutants Under Selection: How Natural Selection Mimics Mutagenesis (Adaptive Mutation)

Science.gov (United States)

Maisnier-Patin, Sophie; Roth, John R.

2015-01-01

Selection detects mutants but does not cause mutations. Contrary to this dictum, Cairns and Foster plated a leaky lac mutant of Escherichia coli on lactose medium and saw revertant (Lac+) colonies accumulate with time above a nongrowing lawn. This result suggested that bacteria might mutagenize their own genome when growth is blocked. However, this conclusion is suspect in the light of recent evidence that revertant colonies are initiated by preexisting cells with multiple copies the conjugative F′lac plasmid, which carries the lac mutation. Some plated cells have multiple copies of the simple F′lac plasmid. This provides sufficient LacZ activity to support plasmid replication but not cell division. In nongrowing cells, repeated plasmid replication increases the likelihood of a reversion event. Reversion to lac+ triggers exponential cell growth leading to a stable Lac+ revertant colony. In 10% of these plated cells, the high-copy plasmid includes an internal tandem lac duplication, which provides even more LacZ activity—sufficient to support slow growth and formation of an unstable Lac+ colony. Cells with multiple copies of the F′lac plasmid have an increased mutation rate, because the plasmid encodes the error-prone (mutagenic) DNA polymerase, DinB. Without DinB, unstable and stable Lac+ revertant types form in equal numbers and both types arise with no mutagenesis. Amplification and selection are central to behavior of the Cairns–Foster system, whereas mutagenesis is a system-specific side effect or artifact caused by coamplification of dinB with lac. Study of this system has revealed several broadly applicable principles. In all populations, gene duplications are frequent stable genetic polymorphisms, common near-neutral mutant alleles can gain a positive phenotype when amplified under selection, and natural selection can operate without cell division when variability is generated by overreplication of local genome subregions. PMID:26134316

Modified Starch of Sorghum Mutant Line Zh-30 for High Fiber Muffin Products

Directory of Open Access Journals (Sweden)

D.D.S. Santosa

2009-01-01

Full Text Available Sorghum mutant line Zh-30 is a breeding line developed at the Center for the Application of Isotope and Radiation Technology, BATAN by using mutation techniques. Gamma irradiation with the dose of 300 Gy was used to induce sorghum genetic variation. Through selection processes in several generations, the mutant line Zh-30 was identified to have better agronomic characteristics, better grain quality and higher grain yield than the original variety. Research on modified starch quality of this mutant line was done to identify its potential use in food industry. Functionality of pregelatinized, hydroxypropyl and crosslinked starch of this mutant line (Mutant TexInstant 30 has been studied for its use in high fiber muffin products. Characteristics of high fiber muffins containing 1.50; 3.50 and 5.50% of Mutant Tex-Instant 30 replacement levels to wheat flour were evaluated using both sensory panel and physical test methods. With regard to the sensory parameters, the high fiber muffins containing 1.50 - 5.50 % Mutant Tex-Instant 30 in general were not significantly different compared to the standard reference muffin. Results of physical evaluations showed that all Mutant Tex-Instant 30 containing products retained more moisture during baking than the standard reference. Tenderness of all products decreased at similar rate following 24 and 48 hr of room temperature storage and seven days at freezer temperature. These results suggested that sorghum mutant line Zh-30 starch could be modified and potentially used in food industry as a subtitute of wheat flour.

Modified Starch of Sorghum Mutant Line Zh-30 For High Fiber Muffin Products

International Nuclear Information System (INIS)

Santosa, D. D. S; Human, S

2009-01-01

Sorghum mutant line Zh-30 is a breeding line developed at the Center for the Application of Isotope and Radiation Technology, BATAN by using mutation techniques. Gamma irradiation with the dose of 300 Gy was used to induce sorghum genetic variation. Through selection processes in several generations, the mutant line Zh-30 was identified to have better agronomic characteristics, better grain quality and higher grain yield than the original variety. Research on modified starch quality of this mutant line was done to identify its potential use in food industry. Functionality of pregelatinized, hydroxypropyl and crosslinked starch of this mutant line (Mutant TexInstant 30) has been studied for its use in high fiber muffin products. Characteristics of high fiber muffins containing 1.50; 3.50 and 5.50% of Mutant Tex-Instant 30 replacement levels to wheat flour were evaluated using both sensory panel and physical test methods. With regard to the sensory parameters, the high fiber muffins containing 1.50 - 5.50 % Mutant Tex-Instant 30 in general were not significantly different compared to the standard reference muffin. Results of physical evaluations showed that all Mutant Tex-Instant 30 containing products retained more moisture during baking than the standard reference. Tenderness of all products decreased at similar rate following 24 and 48 hr of room temperature storage and seven days at freezer temperature. These results suggested that sorghum mutant line Zh-30 starch could be modified and potentially used in food industry as a subtitute of wheat flour (author)

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.

Excision repair in MUT-mutants of Proteus mirabilis after UV-irradiation

International Nuclear Information System (INIS)

Stoerl, K.; Mund, C.

1977-01-01

The behaviour of MUT-mutants of P.mirabilis to perform certain steps of excision repair after U.V.-irradiation is described. MUT-mutants introduce single-strand breaks in the DNA immediately after U.V.-irradiation, but their ability to excise pyrimidine dimers from the DNA is very diminished. Moreover, they are not able to accomplish the excision repair by rejoining of the single-strand breaks. The connection between the incomplete excision repair and the mutator phenotype of these mutants is discussed. (author)

A temperature-sensitive winter wheat chlorophyll mutant derived from space mutagenesis

International Nuclear Information System (INIS)

Zhao Hongbin; Guo Huijun; Zhao Linshu; Gu Jiayu; Zhao Shirong; Li Junhui; Liu Luxiang

2010-01-01

A temperature-sensitive winter wheat (Triticum aestivum L.) chlorophyll mutant Mt18, induced by spaceflight mutagenesis, was studied on agronomic traits, ultrastructure of chloroplast and photosynthesis characteristics. The leaf color of the mutant Mt18 showed changes from green to albino and back to green during the whole growth period. Plant height, productive tillers, spike length, grains and grain weight per plant, and 1000-grain weight of the mutant were lower than those of the wild type. The ultrastructural observation showed that no significant difference was found between the mutant and the wild type during prior albino stage, however, at the albino stage the number of granum-thylakoids and grana lamellae became fewer or completely disappeared, but the strom-thylakoid was obviously visible. After turning green,the structure of most chloroplasts recovered to normal, but number of chloroplast was still lower than that of the wild type. When exposed to photosynthetic active radiation (PAR) of 110 μmol·m -2 ·s -1 , the non-photochemical quenching (NPQ) of mutant was significantly lower than that of the wild type, and the non-regulated energy dissipation (Y NO ) was significantly higher than that of the wild type, while the change of the maximum photosystem II quantum yield (F v /F m ), potential activity of photosystem II (F v /F o ), photochemical quenching (q P ), effective quantum yield (Y PSI I) and regulated non-photochemical energy dissipation (Y NPQ ) were different at various stages. In addition, the differences of the electron transport rate (ETR), photochemical quenching (q P ), and effective quantum yield (Y PSI I) between mutant and wild type varied under different PAR conditions. It was concluded that with the change of chloroplast ultrastructure, the leaf color and photosynthesis of the wheat mutant Mt18 change correspondingly. The chloroplast ultrastructure was obviously different from that of wild type, and the photosynthetic efficiency

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 ...

Relations between protein production, protein quality and environmental factors in Pisum mutants

International Nuclear Information System (INIS)

Gottschalk, W.; Mueller, H.P.; Wolff, G.

1975-01-01

The seed protein content of 138 radiation-induced Pisum mutants was determined. The variability of this genetically well-defined material agrees approximately with that of the world collection of Pisum sativum. Some environmental factors to a great extent influence the protein production of the mutants and the initial line. Therefore, it is necessary to consider the relations between the genetically controlled protein production and its dependence upon the environmental factors. This is especially evident if the protein situation of the same genotypes cultivated under the moderate climatic conditions of middle Europe is compared with the subtropical conditions of India. A generally firm correlation between seed size and protein content could not be found in material regarding 148 different mutants of our assortment. Therefore, the selection of small-grained mutants does not result in a selection of protein-rich genotypes in Pisum sativum. Considering all the criteria positively and negatively influencing the protein production, a positive situation could be found in some mutants, especially in the fasciated ones. Furthermore, an improvement of the protein quality could be reached by a genetically conditioned alteration of the globulin-albumin ratio leading to an increase of some essential amino acids such as methionine and lysine. The combined action of mutant genes results in unexpected changes of the protein quantity as well as the quality of the recombinants in relation to their parental mutants. The comparison of some essential amino acids of our useful mutants with those of the varieties of other genera of the Leguminosae shows certain trends of biochemical alterations realized during evolutionary development of the family. (author)

Study of the UV-sensitivity of the morphological Salmonella typhimurium mutant

Energy Technology Data Exchange (ETDEWEB)

Sakanyan, V A; Dombrovskii, A M; Belokrysenko, S S; Levashev, V S [Vtoroj Moskovskij Gosudarstvennyj Meditsinskij Inst. (USSR)

1975-05-01

As regards sensitivity to ultraviolet radiation, the morphological mutant S. typhimurium LT2 WT ED 143 is similar to the ion-mutants E. coli K12. Data are presented on the sensitivity of the mutant and initial strains to ultraviolet radiation at various phases of growth, on the capacity for restoring the bacteriophages P22 and Felix O after irradiation and on the influence of various treatments after ultraviolet irradiation (incubation in minimum media and at 42/sup 0/ C) on the irradiated strains. The results of densitometry of the membrane proteins of the initial and mutant strains point to a connection between unusual morphology, the disruption of division and the enhanced sensitivity to ultraviolet radiation on one hand and the state of the membrane components of the bacterial cell on the other.

Evaluation of induced mutants of wheat for resistance to fungal diseases

International Nuclear Information System (INIS)

Barriga B, P.; Fuentes P, R.; Andrade S, N.; Seeman F, P.

1990-01-01

Evaluation of induced mutants of wheat for resistance to fungal diseases. Seeds of spring wheat cultivars Austral and Huenufen were exposed to gamma radiation in doses of 0.10 and 0.25 KGy with the objective of producing genotypes resistant to the main fungal diseases, with a high protein content and grain yield, for the southern region of Chile (39 sup(o)-44 sup(o) Latitude south). The selection process and evaluation up to the generation M sub(8) has made possible to identify mutants with a higher protein content and grain yield. Progress made in improving resistance to Puccinia striiformis and tolerance to Septoria spp., has also been important. Some selected mutants, conditioned to their future performance, could be directly used as commercial varieties and other mutants, on crosses with regionally adapted cultivars. (author)

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)

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.

Studies on leaf mutants of Pea. (Part) I. Morphology, performance and somatic chromosomes

International Nuclear Information System (INIS)

Kaul, M.L.H.; Anjali, A.

1988-01-01

Three recessive non-allelic mutant genes alter foliar morphology of pea when present singly and in combination. Gene acacia replaces tendrils by a terminal leaflet, afila replaces leaflets by tendrils and cochleata replaces stipules by spoon shaped appendages. In combination, these genes drastically alter leaf morphology; plants can be identified only after flowering. The mutant genes influence shoot height, floral organ number, maturity period, grain yield and seed protein production; inter- and intra-genotypic variability in certain metric traits is significant. Influence of cochleata gene over floral form and function is considerable. In terms of seed yield and protein content, breeding value of all the mutants except of acacia is low because these mutant genes represent foreign untuned genes in pea genome. Segregation deficit is maximum in triple gene mutant with highly impaired fertility and low seed production. Somatic chromosome number in all the mutants and recombinants is 14; in morphology the chromosomes do not differ from the initial line, Bonneville. (author). 9 refs., 4 tabs

Polyhydroxyalcanoates of strains of Azospirillum spp. isolated of roots of Lycopersicon esculentum Mill. “tomato” and Oryza sativa L. “rice” in Lambayeque

Directory of Open Access Journals (Sweden)

Katty Baca

2010-12-01

Full Text Available In this work was determined the concentration of polyhydroxyalkanoates (PHAs of Azospirillum strains isolated from roots of Lycopersicon esculentum Mill "tomato" and Oryza sativa L. "rice" as an alternative to accumulation of petroleum-based plastics. Previously disinfected root were plated in Nfb semisolid medium where nitrogen-fixing bacteria were recognized by a whitish film on the surface and turn from green to blue. The genus Azospirillum was identified in Congo red agar medium, obtained 96 isolates of A. lipoferum and A. brasilense on tomato and rice. Batch fermentation was performed with broth Azotobacter modified feeding a saturated solution of malic acid every 12 hours and were stained with Sudan Black B. Strains were selected with the greatest number of PHAs granules (in tomato, 18 of A. lipoferum and 2 of A. brasilense; in rice, 10 of A. lipoferum and 10 of A. brasilense and quantified the biomass and PHAs. PHAs concentration reached 0.661 gL-1 in A. lipoferum KM(T-73 and 0.738 gL-1 in A. brasilense KM(T-19, both isolated from tomato. Strains of A. lipoferum and A. brasilense isolated from tomato reached a higher concentration of biomass and PHAs against the strains of rice.

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

High yielding and early maturing mutants in mungbean (Vigna radiata (L) Wilczek)

International Nuclear Information System (INIS)

Malik, I.A.

1988-01-01

Mungbean in Pakistan is grown on about 79 thousand hectares with an annual production of around 39600 t. The poor yield of cultivars may be largely due to their indeterminate excessive vegetative growth, low harvest index, and susceptibility to various diseases. Lack of synchrony in maturity and pod shattering are also limiting factors. Mutation breeding of mungbean at NIAB has the object of evolving early and uniform maturing high yielding mutants. Seeds of mungbean strains Pak-22 and RC71-27 were irradiated with 60 Co gamma rays (5 kR to 80 kR) in 1977. After selecting mutants in the M 2 , further selections were made in M 3 for earliness, uniform maturity, short plant stature and larger number of pods/plant. In the M 4 , 62 selections were subjected to micro plot yield trials and seed protein analysis. Selection was continued in the advanced generations and performance was studied in multilocational trials arranged through the Department of Agriculture. The important characteristics of two mutants namely NM19-19 (derivative of strain Pak 22 at 40 kR) and NM121-25 (derivative of strain RC71-27 at 20 kR) are listed and their field performance is summarized. Both the mutants are short statured and have erect determinate growth habit. They mature early by a margin of 16 days and yield higher. The high harvest index of the mutants indicates their efficiency in partitioning photosynthates towards grain formation. Because of their synchrony in maturity and top fruit bearing habit the mutants are amenable to mechanized harvesting. The early maturity in mutants also makes them more suitable for intercropping practices. The mutants possess greater degree of tolerance to yellow mosaic disease and have shown wide adaptability and stability when grown under different agroclimatic conditions. Both the mutants have been released in 1986, by the Punjab Seed Council as commercial varieties under the names of 'NIAB Mung 121-25' and 'NIAB Mung 19-19' respectively

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)

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)

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

Effect of Simulated Acid Rain on the Germination, Growth, Elements, Protein and Photosynthetic Pigments Contents in Tomato (Lycopersicon esculentum

Directory of Open Access Journals (Sweden)

M. Askary

2014-04-01

Full Text Available Uncontrolled use of fossil fuels in industries and the transport sector has led to an increase in concentrations of gaseous pollutants such as sulphur dioxide (SO2, nitrogen dioxide (NO2 and their derivatives and ozone (O3. In addition to dry and wet deposition of these gases has been the major route of influx in ionic form into the ecosystem. This investigation was evaluated the effects of simulated acid rain (SAR with different pH (6.8 as control, 6.5, 6, 5.5, 5, 4.5, 4, 3.5, 3 and 2.5 on germination, growth, elements, protein, photosynthetic pigments contents of Lycopersicon esculentum in hydroponic culture. Experiments were conducted at research laboratory of arak university in summer of 1391. Results were showed that from pH=6.8 until pH=5/5 significantly increased P and K and protein content, root and shoot dry and wet weight. SAR exposure with high acidity (pH=5/5 until pH=2.5 significantly suppressed germination, growth index, measured elements as P and K, protein and photosynthetic pigments, while significant increased sulphur contect from 150% to 550% compared to controls. Maximal amounts sulphur were measured in pH=2/5. Acid rain in low pH were decrease plant growth and make protein and incearsed sulphur content in leaf. As regards, low acidity promoted the growth of tomato plants and high acidity inhibit, Therefore, it is recommended that tomato plants cultures in soils with low acidity.

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.

Mutants with Enhanced Nitrogenase Activity in Hydroponic Azospirillum brasilense-Wheat Associations

Science.gov (United States)

Pereg Gerk, Lily; Gilchrist, Kate; Kennedy, Ivan R.

2000-01-01

The effect of a mutation affecting flocculation, differentiation into cyst-like forms, and root colonization on nitrogenase expression by Azospirillum brasilense is described. The gene flcA of strain Sp7 restored these phenotypes in spontaneous mutants of both strains Sp7 and Sp245. Employing both constitutive pLA-lacZ and nifH-lacZ reporter fusions expressed in situ, the colony morphology, colonization pattern, and potential for nitrogenase activity of spontaneous mutants and flcA Tn5-induced mutants were established. The results of this study show that the ability of Sp7 and Sp245 mutant strains to remain in a vegetative form improved their ability to express nitrogenase activity in association with wheat in a hydroponic system. Restoring the cyst formation and colonization pattern to the spontaneous mutant Sp7-S reduced nitrogenase activity rates in association with plants to that of the wild-type Sp7. Although Tn5-induced flcA mutants showed higher potentials for nitrogenase expression than Sp7, their potentials were lower than that of Sp7-S, indicating that other factors in this strain contribute to its exceptional nitrogenase activity rates on plants. The lack of lateral flagella is not one of these factors, as Sp7-PM23, a spontaneous mutant impaired in swarming and lateral-flagellum production but not in flocculation, showed wild-type nitrogenase activity and expression. The results also suggest factors of importance in evolving an effective symbiosis between Azospirillum and wheat, such as increasing the availability of microaerobic niches along the root, increased supply of carbon sources by the plant, and the retention of the bacterial cells in vegetative form for faster metabolism. PMID:10788397

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

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

Hypermutability of a UV-sensitive aphidicolin-resistant mutant of Chinese hamster fibroblasts

International Nuclear Information System (INIS)

Liu, P.K.; Chang, C.; Trosko, J.E.

1982-01-01

An ultraviolet light (UV)-sensitive thymidine auxotroph of Chinese hamster V79 cells that exhibits pleiotropic effects such as a high level of deoxycytidine triphosphate, slow growth, sensitivity to cytidine, and high frequencies of site-specific bromodeoxyuridine-dependent chromosomal aberrations was selected by its resistance to aphidicolin. The UV-induced mutability of this mutant and one of its revertants, which retains some of the phenotypes listed above, was studied in 3 mutation assay systems. The results showed that the mutant was hypermutable for ouabain and diphtheria-toxin-resistant mutations compared to wild-type V79 cells at the same UV dose or the same survival level. The mutant exhibits a delayed expression of maximal frequency of induced 6-thioguanine-resistant mutants. When maximal frequencies are compared at the same UV dose, the mutant also has higher mutation frequencies at the hypoxanthine-guanine phosphoribosyl transferase locus. The revertant was similar to the wild-type in UV sensitivity and mutability. (orig./AJ)

Isolation and characterization of acyclovir-resistant mutants of herpes simplex virus.

Science.gov (United States)

Field, H J; Darby, G; Wildy, P

1980-07-01

Mutants of HSV which are resistant to acyclovir (acycloguanosine) have been isolated following serial passages of several herpes simplex virus (HSV) strains in the presence of the drug. The majority of the mutants isolated are defective in induction of thymidine kinase (TK) and this is consistent with the observation that independently isolated TK- viruses are naturally resistant to ACV. One mutant is described (SC16 R9C2) which is resistant in biochemically transformed cells which express HSV TK. This suggests that its resistance resides at a level other than TK. It is also resistant to phosphonoacetic acid, suggesting that the DNA polymerase locus may be involved. A further mutant is described [Cl (101) P2C5] which induces normal levels of TK, although the nature of resistance of this virus is not yet elucidated.

Absence-like and tonic seizures in aspartoacylase/attractin double-mutant mice.

Science.gov (United States)

Gohma, Hiroshi; Kuramoto, Takashi; Matalon, Reuben; Surendran, Sankar; Tyring, Stephen; Kitada, Kazuhiro; Sasa, Masashi; Serikawa, Tadao

2007-04-01

The Spontaneously Epileptic Rat (SER), a double-mutant for tremor and zitter mutations, shows spontaneous occurrences of absence-like and tonic seizures. Several lines of evidence suggest that the combined effect of Aspa and Atrn mutations is the most likely cause of the epileptic phenotype of the SER. To address this issue, we produced a new double-mutant mouse line carrying both homozygous Aspa-knockout and Atrn(mg-3J) mutant alleles. The Aspa/Atrn double-mutant mice exhibited absence-like and tonic seizures that were characterized by the appearance of 5-7 Hz spike-wave-like complexes and low voltage fast waves on EEGs. These results demonstrate directly that the simultaneous loss of the Aspa and Atrn gene functions causes epileptic seizures in the mouse and suggest that both Aspa and Atrn deficiencies might be responsible for epileptic seizures in the SER.

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

Mapping of barley alpha-amylases and outer subsite mutants reveals dynamic high-affinity subsites and barriers in the long substrate binding cleft

DEFF Research Database (Denmark)

Kandra, L.; Abou Hachem, Maher; Gyemant, G.

2006-01-01

Subsite affinity maps of long substrate binding clefts in barley alpha-amylases, obtained using a series of maltooligosaccharides of degree of polymerization of 3-12, revealed unfavorable binding energies at the internal subsites -3 and -5 and at subsites -8 and +3/+4 defining these subsites...... as binding barriers. Barley a-amylase I mutants Y105A and T212Y at subsite -6 and +4 resulted in release or anchoring of bound substrate, thus modifying the affinities of other high-affinity subsites (-2 and +2) and barriers. The double mutant Y105A-T212Y displayed a hybrid subsite affinity profile......, converting barriers to binding areas. These findings highlight the dynamic binding energy distribution and the versatility of long maltooligosaccharide derivatives in mapping extended binding clefts in a-amylases....

Isolation and characteristics of minute plaque forming mutant of cyanophage AS-1

International Nuclear Information System (INIS)

Amla, D.V.

1981-01-01

Minute plaque forming mutant (m) of cyanophage AS-1 infecting unicellular blue-green algae was isolated spontaneously and after mutagenic treatment. Compared to wild type m mutant formed small plaques, adsorption rate was slow and the burst-size was significantly decreased with prolonged eclipse and latent period. The plaque forming ability of mutant phage was sensitive to pH, heat, EDTA shock, distilled water and photosensitisation with acriflavine whereas ultraviolet sensitivity of free and intracellular phage was identical to the parent. The spontaneous reversion frequencies of mutant phage to wild type were between 10 -5 to 10 -3 and appeared to be clonal property. Reversion studies suggested possibilities of frame-shift or base-pair substitution for m mutation. (author)

Isolation and characterization of prophage mutants of the defective Bacillus subtilis bacteriophage PBSX

International Nuclear Information System (INIS)

Thurm, P.; Garro, A.J.

1975-01-01

Bacillus subtilis mutants with lesions in PBSX prophage genes have been isolated. One of these appears to be a regulatory mutant and is defective for mitomycin C-induced derepression of PBSX; the others are defective for phage capsid formation. All of the PBSX structural proteins are synthesized during induction of the capsid defective mutants; however, several of these proteins exhibit abnormal serological reactivity with anti-PBSX antiserum. The two head proteins X4 and X7 are not immunoprecipitable in a mutant which fails to assemble phage head structures. In the tail mutant, proteins X5 and X6 are not immunoprecipitable, tails are not assembled, and a possible tail protein precursor remains uncleaved. The noninducible mutant does not synthesize any PBSX structural proteins after exposure to mitomycin C. The mutation is specific for PBSX since phi 105 and SPO2 lysogens of the mutant are inducible. All of the known PBSX-specific mutations were shown to be clustered between argC and metC on the host chromosome. In addition, the metC marker was shown to be present in multiple copies in cells induced for PBSX replication. This suggests that the derepressed prophage replicates while still integrated and that replication extends into the adjacent regions of the host chromosome

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)

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.

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

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)

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.

Characterization of Brucella abortus mutant strain Δ22915, a potential vaccine candidate.

Science.gov (United States)

Bao, Yanqing; Tian, Mingxing; Li, Peng; Liu, Jiameng; Ding, Chan; Yu, Shengqing

2017-04-04

Brucellosis, caused by Brucella spp., is an important zoonosis worldwide. Vaccination is an effective strategy for protection against Brucella infection in livestock in developing countries and in wildlife in developed countries. However, current vaccine strains including S19 and RB51 are pathogenic to humans and pregnant animals, limiting their use. In this study, we constructed the Brucella abortus (B. abortus) S2308 mutant strain Δ22915, in which the putative lytic transglycosylase gene BAB_RS22915 was deleted. The biological properties of mutant strain Δ22915 were characterized and protection of mice against virulent S2308 challenge was evaluated. The mutant strain Δ22915 showed reduced survival within RAW264.7 cells and survival in vivo in mice. In addition, the mutant strain Δ22915 failed to escape fusion with lysosomes within host cells, and caused no observable pathological damage. RNA-seq analysis indicated that four genes associated with amino acid/nucleotide transport and metabolism were significantly upregulated in mutant strain Δ22915. Furthermore, inoculation of ∆22915 at 10 5 colony forming units induced effective host immune responses and long-term protection of BALB/c mice. Therefore, mutant strain ∆22915 could be used as a novel vaccine candidate in the future to protect animals against B. abortus infection.

Induction of short culm mutants for bread wheat by using gamma rays

International Nuclear Information System (INIS)

Sobieh, S.S.

2002-01-01

This investigation was conducted at the experimental farm of plant research department, nuclear research center, atomic energy authority, Inshas in order to select some short culm mutants from the local wheat varieties; Sid's-5, Sid's-6 and Sid's-7 after gamma irradiation. The obtained results indicated that: 1-M 4 mutants progenies retained the features of their M 3 selections. 2-Some short culm mutants exhibited high grain yield/plant as compared to their original varieties. 3-There were significant decreases in plant height varied from 21.4 to 35.4%. This reduction was due to the shorting of culm inter nods length. As well as, the reduction diameter/culm especially diameter of the inter nods/culm did not differed between original varieties and the mutants. 4-The correlation between grain yield/plant and number of spikes/plant was positive and highly significant for most mutants and the original varieties as well. Data also showed that there were positive relationship between grain yield/plant and number of grains/spike and and length of the inter nods/culm. Positive or negative association between grain yield/plant and plant height as well as diameters of inter nods/culm for mutants and original varieties were detected

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.

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)

Decreased uv mutagenesis in cdc8, a DNA replication mutant of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, L.; Hinkle, D.; Prakash, S.

1978-01-01

A DNA replication mutant of yeast, cdc8, was found to decrease uv-induced reversion of lys2-1, arg4-17, tryl and ural. This effect was observed with all three alleles of cdc8 tested. Survival curves obtained following uv irradiation in cdc8 rad double mutants show that cdc8 is epistatic to rad6, as well as to rad1; cdc8 rad51 double mutants seem to be more sensitive than the single mutants. Since uv-induced reversion in cdc8 rad1 and cdc8 rad51 double mutants is like that of the cdc8 single mutants, we conclude that CDC8 plays a direct role in error-prone repair. To test whether CDC8 codes for a DNA polymerase, we have purified both DNA polymerase I and DNA polymerase II from cdc8 and CDC+ cells. The purified DNA polymerases from cdc8 were no more heat labile than those from CDC+, suggesting that CDC8 is not a structural gene for either enzyme

Interaction of a non-peptide agonist with angiotensin II AT1 receptor mutants

DEFF Research Database (Denmark)

Costa-Neto, Claudio M; Miyakawa, Ayumi A; Pesquero, João B

2002-01-01

and inositol phosphate turnover assays in COS-7 cells transiently transfected with the wild-type and mutant forms of the receptor. Mutant receptors bore modifications in the extracellular region: T88H, Y92H, G1961, G196W, and D278E. Compound L-162,313 displaced [125I]-Sar1,Leu8-AngII from the mutants G196I...... and G196W with IC50 values similar to that of the wild-type. The affinity was, however, slightly affected by the D278E mutation and more significantly by the T88H and Y92H mutations. In inositol phosphate turnover assays, the ability of L-162,313 to trigger the activation cascade was compared...... with that of angiotensin II. These assays showed that the G196W mutant reached a relative maximum activation exceeding that of the wild-type receptor; the efficacy was slightly reduced in the G1961 mutant and further reduced in the T88H, Y92H, and D278E mutants. Our data suggest that residues of the extracellular domain...

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, ...

TOMATOMA Update: Phenotypic and Metabolite Information in the Micro-Tom Mutant Resource.

Science.gov (United States)

Shikata, Masahito; Hoshikawa, Ken; Ariizumi, Tohru; Fukuda, Naoya; Yamazaki, Yukiko; Ezura, Hiroshi

2016-01-01

TOMATOMA (http://tomatoma.nbrp.jp/) is a tomato mutant database providing visible phenotypic data of tomato mutant lines generated by ethylmethane sulfonate (EMS) treatment or γ-ray irradiation in the genetic background of Micro-Tom, a small and rapidly growing variety. To increase mutation efficiency further, mutagenized M3 seeds were subjected to a second round of EMS treatment; M3M1 populations were generated. These plants were self-pollinated, and 4,952 lines of M3M2 mutagenized seeds were generated. We checked for visible phenotypes in the M3M2 plants, and 618 mutant lines with 1,194 phenotypic categories were identified. In addition to the phenotypic information, we investigated Brix values and carotenoid contents in the fruits of individual mutants. Of 466 samples from 171 mutant lines, Brix values and carotenoid contents were between 3.2% and 11.6% and 6.9 and 37.3 µg g(-1) FW, respectively. This metabolite information concerning the mutant fruits would be useful in breeding programs as well as for the elucidation of metabolic regulation. Researchers are able to browse and search this phenotypic and metabolite information and order seeds of individual mutants via TOMATOMA. Our new Micro-Tom double-mutagenized populations and the metabolic information could provide a valuable genetic toolkit to accelerate tomato research and potential breeding programs. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Saccharomyces cerevisiae mutants with enhanced induced mutation and altered mitotic gene conversion.

Science.gov (United States)

Ivanov, E L; Kovaltzova, S V; Korolev, V G

1989-08-01

We have developed a method to isolate yeast (Saccharomyces cerevisiae) mutants with enhanced induced mutagenesis based on nitrous acid-induced reversion of the ade2-42 allele. Six mutants have been isolated and designated him (high induced mutagenesis), and 4 of them were studied in more detail. The him mutants displayed enhanced reversion of the ade2-42 allele, either spontaneous or induced by nitrous acid, UV light, and the base analog 6-N-hydroxylaminopurine, but not by gamma-irradiation. It is worth noting that the him mutants turned out not to be sensitive to the lethal effects of the mutagens used. The enhancement in mutation induced by nitrous acid, UV light, and 6-N-hydroxylaminopurine has been confirmed in a forward-mutation assay (induction of mutations in the ADE1, ADE2 genes). The latter agent revealed the most apparent differences between the him mutants and the wild-type strain and was, therefore, chosen for the genetic analysis of mutants, him mutations analyzed behaved as a single Mendelian trait; complementation tests indicated 3 complementation groups (HIM1, HIM2, and HIM3), each containing 1 mutant allele. Uracil-DNA glycosylase activity was determined in crude cell extracts, and no significant differences between the wild-type and him strains were detected. Spontaneous mitotic gene conversion at the ADE2 locus is altered in him1 strains, either increased or decreased, depending on the particular heteroallelic combination. Genetic evidence strongly suggests him mutations to be involved in a process of mismatch correction of molecular heteroduplexes.

Characterization of novel Sorghum brown midrib mutants from an EMS-mutagenized population.

Science.gov (United States)

Sattler, Scott E; Saballos, Ana; Xin, Zhanguo; Funnell-Harris, Deanna L; Vermerris, Wilfred; Pedersen, Jeffrey F

2014-09-02

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr mutants were identified that were not allelic to these previously described loci. Further allelism testing among these six bmr mutants showed that they represented four novel bmr loci. Based on this study, the number of bmr loci uncovered in sorghum has doubled. The impact of these lines on agronomic traits and lignocellulosic composition was assessed in a 2-yr field study. Overall, most of the identified bmr lines showed reduced lignin concentration of their biomass relative to wild-type (WT). Effects of the six new bmr mutants on enzymatic saccharification of lignocellulosic materials were determined, but the amount of glucose released from the stover was similar to WT in all cases. Like bmr2, bmr6, and bmr12, these mutants may affect monolignol biosynthesis and may be useful for bioenergy and forage improvement when stacked together or in combination with the three previously described bmr alleles. Copyright © 2014 Sattler et al.

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

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

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

Evaluation and genetic analysis of semi-dwarf mutants in rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Awan, M.A.; Cheema, A.A.; Tahir, G.R.

1984-01-01

Four semi-dwarf mutants namely DM16-5-1, DM16-5-2, DM-2 and DM107-4 were derived from the local tall basmati cultivar. The mode of reduction of internode length was studied in DM107-4. The reduction in culm length was due to a corresponding but disproportionate reduction in all the internodes. It was inferred that reduction in internode length contributes more towards reduction in height as compared to the reduction in the total number of internodes. The effect of semi-dwarfism on some yield components (panicle characters) was studied in two semi-dwarf mutants viz. DM16-5-1 and DM107-4 compared to Basmati 370. A marginal reduction in the panicle axis, primary branches per panicle, secondary branches per primary branch per panicle, spikelets borne on secondary branches and total number of spikelets per panicle was observed in DM16-5-1, whereas, a significant reduction of these characters was observed in DM107-4. Evaluation of the semi-dwarf mutants with respect to grain yield and harvest index showed that all the mutants possess high yield potential with higher harvest index values compared to the parent cultivar. Genetic analysis for plant height in 4x4 diallel involving semi-dwarf mutants revealed that mutant DM107-4 carries mainly recessive alleles while mutant DM16-5-1 showed some dominance effects as assessed through the estimates of genetic components of variation and Vr,Wr graph analysis. The semi-dwarf mutants have good potential for use as parents in cross-breeding programmes. (author)

Evaluation of rice mutant lines for resistance to brown planthopper, nilaparvata lugens stall

International Nuclear Information System (INIS)

Mugiono

1985-01-01

The most important and common insect in rice cultivation in South East Asia is brown planthopper, nilaparvata lugens stall. Seven rice mutant lines produced by the National Atomic Energy Agency, Indonesia, were tested at IRRI, the Philippines for resistance to brown planthopper. Those mutant lines were Atomita 1, 627/10-3/PsJ, Atomita 2 and 627/4-E/PsJ originated from Pelita 1/1 which was irradiated with 0.2 kGy of gamma rays and A227/2/PsJ, A227/3/PsJ and A227/5/PsJ, originated from early maturing mutant A23/PsJ/72K from irradiated Pelita 1/1 which was irradiated with 0.1 kGy of gamma rays. Evaluation of resistance was carried out by seedling bulk screening, honeydew excretion, survival and population build up tests by using brown planthopper biotype 1, 2 and 3. Results of these tests showed that the seven tested mutant lines were resistant to biotype 1 but susceptible to biotype 2. Reaction to biotype 3 showed that six mutant lines tested were moderately resistant and only one mutant of 627/4-E/PsJ was susceptible. Reactions of the mutant lines to biotype 1, 2 and 3 were different from the resistant varieties, Mudgo or ASD-7. This indicated that mutant lines might have gene(s) for resistance which differed from those of resistant varieties. The results showed that resistance to brown planthopper is possible to be introduced in Indonesian rice varieties by means of mutations. (author)

Conversion of neurons and glia to external-cell fates in the external sensory organs of Drosophila hamlet mutants by a cousin-cousin cell-type respecification.

Science.gov (United States)

Moore, Adrian W; Roegiers, Fabrice; Jan, Lily Y; Jan, Yuh-Nung

2004-03-15

The Drosophila external sensory organ forms in a lineage elaborating from a single precursor cell via a stereotypical series of asymmetric divisions. HAMLET transcription factor expression demarcates the lineage branch that generates two internal cell types, the external sensory neuron and thecogen. In HAMLET mutant organs, these internal cells are converted to external cells via an unprecedented cousin-cousin cell-fate respecification event. Conversely, ectopic HAMLET expression in the external cell branch leads to internal cell production. The fate-determining signals NOTCH and PAX2 act at multiple stages of lineage elaboration and HAMLET acts to modulate their activity in a branch-specific manner.

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.

Clathrin-dependent internalization, signaling, and metabolic processing of guanylyl cyclase/natriuretic peptide receptor-A.

Science.gov (United States)

Somanna, Naveen K; Mani, Indra; Tripathi, Satyabha; Pandey, Kailash N

2018-04-01

Cardiac hormones, atrial and brain natriuretic peptides (ANP and BNP), have pivotal roles in renal hemodynamics, neuroendocrine signaling, blood pressure regulation, and cardiovascular homeostasis. Binding of ANP and BNP to the guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) induces rapid internalization and trafficking of the receptor via endolysosomal compartments, with concurrent generation of cGMP. However, the mechanisms of the endocytotic processes of NPRA are not well understood. The present study, using 125 I-ANP binding assay and confocal microscopy, examined the function of dynamin in the internalization of NPRA in stably transfected human embryonic kidney-293 (HEK-293) cells. Treatment of recombinant HEK-293 cells with ANP time-dependently accelerated the internalization of receptor from the cell surface to the cell interior. However, the internalization of ligand-receptor complexes of NPRA was drastically decreased by the specific inhibitors of clathrin- and dynamin-dependent receptor internalization, almost 85% by monodansylcadaverine, 80% by chlorpromazine, and 90% by mutant dynamin, which are specific blockers of endocytic vesicle formation. Visualizing the internalization of NPRA and enhanced GFP-tagged NPRA in HEK-293 cells by confocal microscopy demonstrated the formation of endocytic vesicles after 5 min of ANP treatment; this effect was blocked by the inhibitors of clathrin and by mutant dynamin construct. Our results suggest that NPRA undergoes internalization via clathrin-mediated endocytosis as part of its normal itinerary, including trafficking, signaling, and metabolic degradation.

Effects of Different Sources of Nutrition on Quantitative and Qualitative Characteristics of Lycopersicon esculentum under Ecological Cropping System

Directory of Open Access Journals (Sweden)

M.B. Amiri

2016-02-01

Full Text Available Introduction: Increasing usage of chemical fertilizers imposes irreparable damages to the environment. Disadvantages of chemical fertilizers has led to more attention to the application of organic fertilizers and manures. The use of organic fertilizers and livestock, especially in nutrient poor soils, it is necessary to maintain soil quality. Plant growth promoting rhizobacteria (PGPR occupy the rhizosphere of many plant species and have beneficial effects on the host plant. They may influence the plant in a direct or indirect manner. A direct mechanism would be to increase plant growth by supplying the plant with nutrients and hormones. Indirect mechanisms on the otherhand, include, reduced susceptibility to diseases, and activing a form of defese referred to as induces systematic resistance. Examples of bacteria which have been found to enhance plant growth, include Pseudomonas, Enterobacter and Arthrobacter. Biofertilizers contain organic compounds that increase soil fertility either directly or as a result of their decay (9, 10. Tomato (Lycopersicon esculentum L. belongs to the nightshade family, Solanaceae. The plant typically grow 1-3 meters in height and a weak stem. It is a perennial in its native habitat, although often grown outdoors in temperate climates as an annual. An average common tomato weighs approximately 100 grams. Tomatoes contain the carotene lycopene, one of the most powerful natural antioxidants. In some studies, lycopene, especially in cooked tomatoes, has been found to help prevent prostate cancer. Lycopene has also been shown to improve the skin’s ability to protect against harmful UV rays. Tomatoes might help in managing human neurodegenerative diseases. The lycopene has no effect on the risk of developing diabetes, but may help relieve the oxidative stress of people who already have diabetes. The purpose of this study was the possibility of replacing chemical fertilizers with biofertilizers, reducing production

Identification of a Gravitropism-Deficient Mutant in Rice

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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.

Mycothiol-Deficient Mycobacterium smegmatis Mutants Are Hypersensitive to Alkylating Agents, Free Radicals, and Antibiotics

Science.gov (United States)

Rawat, Mamta; Newton, Gerald L.; Ko, Mary; Martinez, Gladys J.; Fahey, Robert C.; Av-Gay, Yossef

2002-01-01

Mycothiol (MSH; 1d-myo-inosityl 2-[N-acetyl-l-cysteinyl]amido-2-deoxy-α-d-glucopyranoside) is the major low-molecular-weight thiol produced by mycobacteria. Mutants of Mycobacterium smegmatis mc2155 deficient in MSH production were produced by chemical mutagenesis as well as by transposon mutagenesis. One chemical mutant (mutant I64) and two transposon mutants (mutants Tn1 and Tn2) stably deficient in MSH production were isolated by screening for reduced levels of MSH content. The MSH contents of transposon mutants Tn1 and Tn2 were found to be less than 0.1% that of the parent strain, and the MSH content of I64 was found to be 1 to 5% that of the parent strain. All three strains accumulated 1d-myo-inosityl 2-deoxy-α-d-glucopyranoside to levels 20- to 25-fold the level found in the parent strain. The cysteine:1d-myo-inosityl 2-amino-2-deoxy-α-d-glucopyranoside ligase (MshC) activities of the three mutant strains were ≤2% that of the parent strain. Phenotypic analysis revealed that these MSH-deficient mutants possess increased susceptibilities to free radicals and alkylating agents and to a wide range of antibiotics including erythromycin, azithromycin, vancomycin, penicillin G, rifamycin, and rifampin. Conversely, the mutants possess at least 200-fold higher levels of resistance to isoniazid than the wild type. We mapped the mutation in the chemical mutant by sequencing the mshC gene and showed that a single amino acid substitution (L205P) is responsible for reduced MSH production and its associated phenotype. Our results demonstrate that there is a direct correlation between MSH depletion and enhanced sensitivity to toxins and antibiotics. PMID:12384335

Induced high yielding mutant in green gram (Vigna radiata (L.) Wilczek)

International Nuclear Information System (INIS)

Pulivarthi, H.R.; Mary, T.N.

1987-01-01

Green gram (mungbean) plays a significant role in meeting the protein requirements in India, with its predominantly vegetarian population. Therefore, an attempt was made to induce desirable mutants. Dry seed of cultivar 'Pusa 105' were irradiated with gamma rays ranging from 10 to 50 krad. A high yielding mutant (Hy I) identified in the M 4 generation from 40 krad dose, has shown significant increases in the number of pods/plants, number of branches/plant, and yield/plant. Further work is in progress. Comparison of the mutant HyI with the parent cultivar Pusa 105 is given

Evaluation of semi-dwarf mutants in triticale and wheat breeding programmes

International Nuclear Information System (INIS)

Driscoll, C.J.

1982-01-01

A number of short-statured triticale plants were selected in M 4 following gamma-ray or EMS treatment of seed of Beagle and DR-IRA triticales. Selection for homozygous mutants will be attempted in M 5 . The Cornerstone male sterility mutant mslc is being combined with the three GA-insensitive, reduced-height mutants Gai/Rht1, Gai/Rht2 and Gai/Rht3 in order to establish a composite cross based on homozygosity of a given Gai/Rht allele. This would allow selection for minor genes for increased height on a GA-insensitive, reduced-height background. (author)

Effects of irradiation-degradated chitosan coating on quality and shelf-life of the fruits of Shatang Mandarin, Fortunella Margariat (LOUR) swingle and Lycopersicon Esculentum MILL. var. cerasiforme alef

International Nuclear Information System (INIS)

Chen Hao; Gao Peng; Gao Ya; Yang Zhirong; Sun Qun

2008-01-01

Effects of irradiation-degradated chiotosan of different molecular weight on weight loss, rotting rate, total acid, soluble solid content, and ascorbic acid in Shatang mandarin, Fortunella margarita (lour) Swingle, and Lycopersicon esculentum Mill. var. cerasiforme Alef during storage were investigated. The result showed that, compared to control, all chitosan treatment could significantly reduce weight loss and rotting rate, and maintain the content of total acid, soluble solid, and ascorbic acid. After 18 days of storage, treatment of chitosan with molecular weight of 6.6 x 10 4 Da showed the highest capability of decreasing the rotting rate in S. mandarin, F. margarita, L. esculentum by 71.11%, 66.01% and 70.22%, respectively; increasing total acid by 55.60%, 36.75% and 36.68%, soluble solid content by 49.06%, 25.75% and 49.46%, and ascorbic acid by 42.80%, 41.65% and 51.70%, respectively. Accordingly, irradiation-degradated chitosan coating could effectively prevent the rotting rate and preserve the quality of the three kinds of fruit during storage and thus prolong their shelf life to 18 days. (authors)

Lack of chemically induced mutation in repair-deficient mutants of yeast

International Nuclear Information System (INIS)

Prakash, L.

1974-01-01

Two genes, rad6 and rad9, that confer radiation sensitivity in the yeast Saccharomyces cerevisiae also greatly reduce the frequency of chemically-induced reversions of a tester mutant cyc1-131, which is a chain initiation mutant in the structural gene determining iso-1-cytochrome c. Mutations induced by ethyl methanesulfonate (EMS), diethyl sulfate (DES), methyl methanesulfonate (MMS), dimethyl sulfate (DMS), nitroquinoline oxide (NQO), nitrosoguanidine (NTG), nitrogen mustard (HN2), β-propiolactone, and tritiated uridine, as well as mutations induced by ultraviolet light (UV) and ionizing radiation were greatly diminished in strains homozygous for either the rad6 or rad9 gene. Nitrous acid and nitrosoimidazolidone (NIL), on the other hand, were highly mutagenic in these repair-deficient mutants, and at low doses, these mutagens acted with about the same efficiency as in the normal RAD strain. At high doses of either nitrous acid or NIL, however, reversion frequencies were significantly reduced in the two rad mutants compared to normal strains. Although both rad mutants are immutable to about the same extent, the rad9 strains tend to be less sensitive to the lethal effect of chemical mutagens than rad6 strains. It is concluded that yeast requires a functional repair system for mutation induction by chemical agents. (auth)

Lack of chemically induced mutation in repair-deficient mutants of yeast.

Science.gov (United States)

Prakash, L

1974-12-01

Two genes, rad6 and rad9, that confer radiation sensitivity in the yeast Saccharomyces cerevisiae also greatly reduce the frequency of chemically-induced reversions of a tester mutant cyc1-131, which is a chain initiation mutant in the structural gene determining iso-1-cytochrome c. Mutations induced by ethyl methanesulfonate (EMS), diethyl sulfate (DES), methyl methanesulfonate (MMS), dimethyl sulfate (DMS), nitroquinoline oxide (NQO), nitrosoguanidine (NTG), nitrogen mustard (HN2), beta-propiolactone, and tritiated uridine, as well as mutations induced by ultraviolet light (UV) and ionizing radiation were greatly diminished in strains homozygous for either the rad6 or rad9 gene. Nitrous acid and nitrosoimidazolidone (NIL), on the other hand, were highly mutagenic in these repair-deficient mutants, and at low doses, these mutagens acted with about the same efficiency as in the normal RAD strain. At high doses of either nitrous acid or NIL, however, reversion frequencies were significantly reduced in the two rad mutants compared to normal strains. Although both rad mutants are immutable to about the same extent, the rad9 strains tend to be less sensitive to the lethal effect of chemical mutagens than rad6 strains. It is concluded that yeast requires a functional repair system for mutation induction by chemical agents.

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)

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

Isolation and characterization of radioresistant mutants in Bacillus subtilis and Bacillus thuringiensis

International Nuclear Information System (INIS)

Kalinin, V.L.; Petrov, V.N.; Petrova, T.M.

1981-01-01

Vegetative cells of Bac. thuringiensis var. galleriae (the wild-type strain 351) are much more sensitive to lethal effects of UV light and 60 Co-γ-rays than those of Bac. subtilis (the wild-type strain 168). This difference is less pronounced for spores of these strains. By means of repeated γ-irradiation-regrowth cycles radioresistant mutants Bac. thuringiensis Gamsup(r) 14 and Bac. subtilis Gamsup(r) 9 were selected. The vegetative cells of these mutants are correspondingly 19 times and 3.9 times more resistant to lethal effects of γ-radiation than the cells of the parental strains. The resistance of the Gamsup(r) mutant cells to lethal effects of UV light and H 2 O 2 is also increased. The spores of the Gamsup(r) 14 mutant are 1.5-1.7 times more resistant to γ-radiation and UV light than the wild-type spores. The radioresistant mutants and the parental strains do not vary in their capacity for host-cell reactivation of UV- or γ-irradiated phages Tg13 and 105

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)

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.

High-content screening of yeast mutant libraries by shotgun lipidomics

DEFF Research Database (Denmark)

Tarasov, Kirill; Stefanko, Adam; Casanovas, Albert

2014-01-01

To identify proteins with a functional role in lipid metabolism and homeostasis we designed a high-throughput platform for high-content lipidomic screening of yeast mutant libraries. To this end, we combined culturing and lipid extraction in 96-well format, automated direct infusion...... factor KAR4 precipitated distinct lipid metabolic phenotypes. These results demonstrate that the high-throughput shotgun lipidomics platform is a valid and complementary proxy for high-content screening of yeast mutant libraries....... nanoelectrospray ionization, high-resolution Orbitrap mass spectrometry, and a dedicated data processing framework to support lipid phenotyping across hundreds of Saccharomyces cerevisiae mutants. Our novel approach revealed that the absence of genes with unknown function YBR141C and YJR015W, and the transcription...

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)

Functional characterization of recombinant snake venom rhodocytin: rhodocytin mutant blocks CLEC-2/podoplanin-dependent platelet aggregation and lung metastasis.

Science.gov (United States)

Sasaki, T; Shirai, T; Tsukiji, N; Otake, S; Tamura, S; Ichikawa, J; Osada, M; Satoh, K; Ozaki, Y; Suzuki-Inoue, K

2018-02-28

interaction-dependent platelet aggregation and experimental lung metastasis. Conclusion These findings provide molecular characterization information on rhodocytin, and suggest that mutant rhodocytin could be used as a therapeutic agent to target CLEC-2. © 2018 International Society on Thrombosis and Haemostasis.

Surface-enhanced Raman spectroscopy of genomic DNA from in vitro grown tomato (Lycopersicon esculentum Mill.) cultivars before and after plant cryopreservation.

Science.gov (United States)

Muntean, Cristina M; Leopold, Nicolae; Tripon, Carmen; Coste, Ana; Halmagyi, Adela

2015-06-05

In this work the surface-enhanced Raman scattering (SERS) spectra of five genomic DNAs from non-cryopreserved control tomato plants (Lycopersicon esculentum Mill. cultivars Siriana, Darsirius, Kristin, Pontica and Capriciu) respectively, have been analyzed in the wavenumber range 400-1800 cm(-1). Structural changes induced in genomic DNAs upon cryopreservation were discussed in detail for four of the above mentioned tomato cultivars. The surface-enhanced Raman vibrational modes for each of these cases, spectroscopic band assignments and structural interpretations of genomic DNAs are reported. We have found, that DNA isolated from Siriana cultivar leaf tissues suffers the weakest structural changes upon cryogenic storage of tomato shoot apices. On the contrary, genomic DNA extracted from Pontica cultivar is the most responsive system to cryopreservation process. Particularly, both C2'-endo-anti and C3'-endo-anti conformations have been detected. As a general observation, the wavenumber range 1511-1652 cm(-1), being due to dA, dG and dT residues seems to be influenced by cryopreservation process. These changes could reflect unstacking of DNA bases. However, not significant structural changes of genomic DNAs from Siriana, Darsirius and Kristin have been found upon cryopreservation process of tomato cultivars. Based on this work, specific plant DNA-ligand interactions or accurate local structure of DNA in the proximity of a metallic surface, might be further investigated using surface-enhanced Raman spectroscopy. Copyright © 2015 Elsevier B.V. All rights reserved.

Mutant in tobacco anther culture induced by 60Co γ-rays

International Nuclear Information System (INIS)

Tong Daoru; Jia Xinghua

1991-01-01

The tobacco anthers at uninucleate eccentric stage were irradiated by 60 Co γ-rays for the purpose of inducing desirable mutants. The results showed that the induction frequency of plantlets increased following 1kR of 60 Co γ-rays treatment. However, the time of plantlet induction was delayed and the percentage of responding anthers as well as the number of plantlets induced per anther significantly decreased after 3kR of 60 Co γ-ray radiation which was considered as a semilethal exposure. The plantlet numbers induced per anther were extremely low following 6kR of 60 Co γ-ray radiation. A white flower mutant appeared in the induced progenies. The tobacco leaf quality of this mutant were significantly improved as compared with its parental line. The mutant line has been tested and proved to have commercial value though the resistance to the black shank of tobacco slightly decreased as compared with the parental line

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)

Induction of two mutants in birdsfoot trefoil (Lotus corniculatus) by x-rays and chemical mutagens

International Nuclear Information System (INIS)

Therrien, M.C.; Grant, W.F.

1982-01-01

The mutagenic effects of X-rays, ethyl methanesulfonate (EMS), 8-ethoxycaffeine (EOC), N-hydroxyurea (HU) and 2-aminopurine (2AP) on seed treatment of birdsfoot trefoil (Lotus corniculatus L. 'Mirabel') were assessed over four generations. Mutants were recovered in the M 2 , M 3 and M 4 generations from selfed lines, from crosses derived form selfed lines and from open pollination lines. Mutant plants exhibiting vestigial floret character were recovered from X-rays, EMS, EOC and HU treatments. Mutant chlorotica plants were obtained from EMS treatment only. No mutants were recovered from 2AP treatment, EMS, the most effective mutagen, produced nine vestigial floret and 12 chlorotica mutants. Mutants were obtained from only one exposure of X-rays (12 krad). There was evidence for preferential elimination of gametes. The chlorotica and vestigial floret mutants were inherited as tetrasomic recessives. Mutation frequencies of 0.4 - 3.1% in a tetrasomic background are indicative of the effectiveness of EMS in birdsfoot trefoil

Induction of two mutants in birdsfoot trefoil (Lotus corniculatus) by x-rays and chemical mutagens

Energy Technology Data Exchange (ETDEWEB)

Therrien, M.C.; Grant, W.F. (McGill Univ., Ste. Anne de Bellevue, Quebec (Canada). Macdonald Coll.)

1982-10-01

The mutagenic effects of X-rays, ethyl methanesulfonate (EMS), 8-ethoxycaffeine (EOC), N-hydroxyurea (HU) and 2-aminopurine (2AP) on seed treatment of birdsfoot trefoil (Lotus corniculatus L. 'Mirabel') were assessed over four generations. Mutants were recovered in the M/sub 2/, M/sub 3/ and M/sub 4/ generations from selfed lines, from crosses derived form selfed lines and from open pollination lines. Mutant plants exhibiting vestigial floret character were recovered from X-rays, EMS, EOC and HU treatments. Mutant chlorotica plants were obtained from EMS treatment only. No mutants were recovered from 2AP treatment, EMS, the most effective mutagen, produced nine vestigial floret and 12 chlorotica mutants. Mutants were obtained from only one exposure of X-rays (12 krad). There was evidence for preferential elimination of gametes. The chlorotica and vestigial floret mutants were inherited as tetrasomic recessives. Mutation frequencies of 0.4 - 3.1% in a tetrasomic background are indicative of the effectiveness of EMS in birdsfoot trefoil.

The yeast complex I equivalent NADH dehydrogenase rescues pink1 mutants.

Directory of Open Access Journals (Sweden)

Sven Vilain

2012-01-01

Full Text Available Pink1 is a mitochondrial kinase involved in Parkinson's disease, and loss of Pink1 function affects mitochondrial morphology via a pathway involving Parkin and components of the mitochondrial remodeling machinery. Pink1 loss also affects the enzymatic activity of isolated Complex I of the electron transport chain (ETC; however, the primary defect in pink1 mutants is unclear. We tested the hypothesis that ETC deficiency is upstream of other pink1-associated phenotypes. We expressed Saccaromyces cerevisiae Ndi1p, an enzyme that bypasses ETC Complex I, or sea squirt Ciona intestinalis AOX, an enzyme that bypasses ETC Complex III and IV, in pink1 mutant Drosophila and find that expression of Ndi1p, but not of AOX, rescues pink1-associated defects. Likewise, loss of function of subunits that encode for Complex I-associated proteins displays many of the pink1-associated phenotypes, and these defects are rescued by Ndi1p expression. Conversely, expression of Ndi1p fails to rescue any of the parkin mutant phenotypes. Additionally, unlike pink1 mutants, fly parkin mutants do not show reduced enzymatic activity of Complex I, indicating that Ndi1p acts downstream or parallel to Pink1, but upstream or independent of Parkin. Furthermore, while increasing mitochondrial fission or decreasing mitochondrial fusion rescues mitochondrial morphological defects in pink1 mutants, these manipulations fail to significantly rescue the reduced enzymatic activity of Complex I, indicating that functional defects observed at the level of Complex I enzymatic activity in pink1 mutant mitochondria do not arise from morphological defects. Our data indicate a central role for Complex I dysfunction in pink1-associated defects, and our genetic analyses with heterologous ETC enzymes suggest that Ndi1p-dependent NADH dehydrogenase activity largely acts downstream of, or in parallel to, Pink1 but upstream of Parkin and mitochondrial remodeling.

Resistance of some early mutant lines of soybean to rust fungus (Phakospora pachyrhizi Syd)

International Nuclear Information System (INIS)

Ratma, Rivaie

1984-01-01

A trial for resistance to rust fungus (Phakospora pachyrhizi Syd.) was conducted on 11 early mutant lines of soybean M6 (derived from Orba variety with a dose of 0.4 kGy of Co-60) at Citayam Experimental Station, Bogor, in the wet season of 80/81. Based on IWGSR rating system, soybean mutant lines number M6/40/6 was moderately susceptible to rust fungus (Phakospora pachyrhizi Syd). While 10 other soybean mutant lines M6/40/1, M6/40/2, M6/40/3, M6/40/4, M6/40/5, M6/40/7, M6/40/8, M6/40/9, M6/40/10 and M6/40/11 were susceptible to rust fungus. Significant differences in yield were observed between the early mutant lines M6/40/6 (moderate susceptible), 10 other mutant lines (susceptible) and ringgit variety (susceptible). However, a significant lower yield was produced by those mutant lines compared with the yield of orba variety. (author)

Induction of high yielding and high protein containing chickpea mutant variety through gamma radiation

International Nuclear Information System (INIS)

Hassan, S.; Javed, M.A.; Khan, A.J.; Tariq, M.

1997-01-01

Pure seeds of a blight susceptible but high yielding chickpea variety 6153 were irradiated at 20 Kr(0.2 kGy) dose of gamma radiation and the mutant line CMN-446-4 was selected in M3 generation on the basis of high yield and disease resistance. After confirmation of its resistance to blight in M4 and M5, the mutant line CMN-446-4 along with other promising chickpea mutants were evaluated in various yield trials at different locations. The mutant line CMN-446-4 was got evaluated in chickpea national uniform yield trial conducted over two locations in the country during 1993-94. The mutant line, on average, ranked 3rd by producing significantly higher yield of 1528 kg/ha as compared to the two checked varieties Punjab-91 and Paidar-91 which yielded 1316 and 1391 kg/ha respectively. The mutant CMN-446-4 has significantly greater percentage of protein content (25.22%) compared to its parental variety having (20.12%). (author)

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)

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)

Grain-filling duration and grain yield relationships in wheat mutants

International Nuclear Information System (INIS)

Larik, A.S.

1987-01-01

Nine stable mutants of bread wheat along with their mother cultivars were investigated for grain-filling characteristics in relation to grain yield. Significant differences among mutants for grain-filling duration and grain-filling index were observed. Inspite of the consistent differences in grain-filling duration there was no significant association between grain-filling duration and grain yield in C-591 and Nayab mutants. Failure to detect an yield advantage due to differences in grain-filling duration in these genotypes suggests that any advantage derived from alteration of grain-filling period may have been outweighed by the coincident changes in length of the vegetative period. Other factors such as synchrony of anthesis may have limited out ability to find an association between grainfilling duration and grain yield. On the contrary, significant association between grain-filling duration and grain yield displayed by indus-66 indus-66 mutants derived from gamma rays, shows the ability of gamma rays to induce functional alternations in the pattern of gene arrangements controlling these traits. Thus, the vaability observed in these physiological traits suggests that selection for these traits could be useful in improving grain yield. (author)

Genetic Analysis of Streaked and Abnormal Floret Mutant st-fon

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De-xi CHEN

2013-07-01

Full Text Available A double mutant with streaked leaf and abnormal floret was found and temporarily named streaked leaf and floral organ number mutant (st-fon. For this mutant, besides white streak appeared on culm, leaves and panicles, the number of floral organs increased and florets cracked. The extreme phenotype was that several small florets grew from one floret or branch rachis in small florets extended and developed into panicles. By using transmission electron microscope to observe the ultrastructure of white histocytes of leaves at the seedling stage, the white tissues which showed abnormal plastids, lamellas and thylakoids could not develop into normal chloroplast, and the development of chloroplast was blocked at the early growth stage of plastid. Scanning electron microscope and paraffin section were also used to observe the development of floral organs, and the results indicated that the development of floral meristem was out of order and unlimited, whereas in the twisty leaves, vascular bundle sheath cells grew excessively, or some bubbly cells increased. Genetic analyses carried out by means of cross and backcross with four normal-leaf-color materials revealed that the mutant is of cytoplasm inheritance.

Italian Nivolumab Expanded Access Program in Nonsquamous Non-Small Cell Lung Cancer Patients: Results in Never-Smokers and EGFR-Mutant Patients.

Science.gov (United States)

Garassino, Marina Chiara; Gelibter, Alain Jonathan; Grossi, Francesco; Chiari, Rita; Soto Parra, Hector; Cascinu, Stefano; Cognetti, Francesco; Turci, Daniele; Blasi, Livio; Bengala, Carmelo; Mini, Enrico; Baldini, Editta; Quadrini, Silvia; Ceresoli, Giovanni Luca; Antonelli, Paola; Vasile, Enrico; Pinto, Carmine; Fasola, Gianpiero; Galetta, Domenico; Macerelli, Marianna; Giannarelli, Diana; Lo Russo, Giuseppe; de Marinis, Filippo

2018-05-03

Nivolumab is the first checkpoint inhibitor approved for the treatment of nonsquamous NSCLC. We report results from the nivolumab Italian expanded access program focusing on never-smokers and patients with EGFR-mutant nonsqamous NSCLC. Nivolumab (3 mg/kg intravenously every 2 weeks) was administered upon physicians' request to patients who had relapsed after one or more prior systemic treatments for stage IIIB/IV nonsquamous NSCLC. Efficacy and safety were evaluated in patients who received at least one dose of nivolumab. Of 1588 patients with nonsquamous NSCLC, 305 (19.2%) were never-smokers. EGFR status was available for 1395 patients. Of the 102 patients (6.4%) with EGFR mutation-positive tumors, 51 (50%) were never-smokers. The objective response rate was significantly higher in patients with wild-type EGFR than patients with EGFR-mutant tumors (19.6% versus 8.8% [p = 0.007]), in former and current smokers than in never-smokers (21.5% versus 9.2% [p = 0.0001]), and in never-smokers with wild-type EGFR than in never-smokers with mutant EGFR (11.0% versus 1.9% [p = 0.04]). There was no significant difference in objective response rate between smokers with wild-type EGFR and smokers with mutant EGFR (22.0% versus 20.6%). There was no statistically significant difference in median progression-free survival or in median overall survival. The median overall survival times were 11 months in patients with EGFR wild-type tumors versus 8.3 months in patients with EGFR-mutant tumors, 11.6 months in smokers versus 10.0 months in never-smokers, 11.0 months in never-smokers with EGFR wild-type tumors versus 5.6 months in never-smokers with EGFR-mutant tumors, and 14.1 months in smokers with EGFR-mutant tumors versus 11.3 months in smokers with EGFR wild-type tumors. The data on the Italian expanded access program in populations with nonsquamous NSCLC suggest that subgroups of patients could benefit differently from nivolumab according to their EGFR mutational status and

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

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.

SRAP analysis for space induced mutant line of maize (Zea mays L.)

International Nuclear Information System (INIS)

Du Wenping; Yu Guirong; Song Jun; Xu Liyuan

2011-01-01

In order to detect the effects of space mutation on maize, 16 SRAP primers were applied for the discrimination of the maize inbred line '968' and its 93 mutant materials, 154 polymorphic fragments were amplified. The average of polymorphic bands detected by per SRAP primer combination was 9.6 with a range from 5 to 18. Genetic similarities among the 94 materials ranged from 0.481 to 1.000 with an average of 0.903, and the largest genetic distance was found between mutant line 37 and control. The 94 materials were divided into six groups with the similarity coefficient of 0.732. The phylogenetic analysis showed distinct variation among the mutants. The results indicated that SRAP markers could be used for analyzing genetic variation of mutants. (authors)

The adhesive properties of the Staphylococcus lugdunensis multifunctional autolysin AtlL and its role in biofilm formation and internalization.

Science.gov (United States)

Hussain, Muzaffar; Steinbacher, Tim; Peters, Georg; Heilmann, Christine; Becker, Karsten

2015-01-01

Although it belongs to the group of coagulase-negative staphylococci, Staphylococcus lugdunensis has been known to cause aggressive courses of native and prosthetic valve infective endocarditis with high mortality similar to Staphylococcus aureus. In contrast to S. aureus, only little is known about the equipment of S. lugdunensis with virulence factors including adhesins and their role in mediating attachment to extracellular matrix and plasma proteins and host cells. In this study, we show that the multifunctional autolysin/adhesin AtlL of S. lugdunensis binds to the extracellular matrix and plasma proteins fibronectin, fibrinogen, and vitronectin as well as to human EA.hy926 endothelial cells. Furthermore, we demonstrate that AtlL also plays an important role in the internalization of S. lugdunensis by eukaryotic cells: The atlL-deficient mutant Mut17 adheres to and becomes internalized by eukaryotic cells to a lesser extent than the isogenic wild-type strain Sl253 and the complemented mutant Mut17 (pCUatlL) shows an increased internalization level in comparison to Mut17. Thus, surface localized AtlL that exhibits a broad binding spectrum also mediates the internalization of S. lugdunensis by eukaryotic cells. We therefore propose an internalization pathway for S. lugdunensis, in which AtlL plays a major role. Investigating the role of AtlL in biofilm formation of S. lugdunensis, Mut17 shows a significantly reduced ability for biofilm formation, which is restored in the complemented mutant. Thus, our data provide evidence for a significant role for AtlL in adherence and internalization processes as well as in biofilm formation of S. lugdunensis. Copyright © 2014 Elsevier GmbH. All rights reserved.

A double-mutant collection targeting MAP kinase related genes in Arabidopsis for studying genetic interactions.

Science.gov (United States)

Su, Shih-Heng; Krysan, Patrick J

2016-12-01

Mitogen-activated protein kinase cascades are conserved in all eukaryotes. In Arabidopsis thaliana there are approximately 80 genes encoding MAP kinase kinase kinases (MAP3K), 10 genes encoding MAP kinase kinases (MAP2K), and 20 genes encoding MAP kinases (MAPK). Reverse genetic analysis has failed to reveal abnormal phenotypes for a majority of these genes. One strategy for uncovering gene function when single-mutant lines do not produce an informative phenotype is to perform a systematic genetic interaction screen whereby double-mutants are created from a large library of single-mutant lines. Here we describe a new collection of 275 double-mutant lines derived from a library of single-mutants targeting genes related to MAP kinase signaling. To facilitate this study, we developed a high-throughput double-mutant generating pipeline using a system for growing Arabidopsis seedlings in 96-well plates. A quantitative root growth assay was used to screen for evidence of genetic interactions in this double-mutant collection. Our screen revealed four genetic interactions, all of which caused synthetic enhancement of the root growth defects observed in a MAP kinase 4 (MPK4) single-mutant line. Seeds for this double-mutant collection are publicly available through the Arabidopsis Biological Resource Center. Scientists interested in diverse biological processes can now screen this double-mutant collection under a wide range of growth conditions in order to search for additional genetic interactions that may provide new insights into MAP kinase signaling. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Recombinant lines for less-spininess in steroid-bearing Solanum viarum using induced mutants as parents

International Nuclear Information System (INIS)

Krishnan, R.; Nanda Kumar, D.; Subhas Chander, M.

1988-01-01

In the domestication of the wild, spinous and steroid-bearing Solanum viarum (syn. S. khasianum var. chatterjeeanum) induced mutations play a major role. The development of Glaxo and BARC mutants catalysed commercial cultivation of this species for its berries containing solasodine, used in steroid industries. The commercially more popular Glaxo mutant population consists predominantly of plants that are totally free of spines in aerial parts except lamina where few straight spines develop. The BARC mutant still possesses spines on aerial parts including the persistent calyx. However, the laminary spines of the BARC mutant are curved and vestigial. Comparative studies on morphology, growth behaviour and agronomic characters of the two mutants, their wild progenitor and their hybrid progenies showed that the three types differ only for spine character. In F 2 generation of a cross involving the Glaxo and BARC mutants, a double mutant recombinant was recovered. The recombinant is devoid of spines in aerial parts like its Glaxo mutant parent, but possesses laminary curved vestigial spines like the BARC parent. The spine characters of the recombinant are inherited double recessive. Three advanced lines of this recombinant type (IIHR 2n - 1,2 and 3) were tested in replicated trials 1985 and 1986. They showed parity in berry yield and solasodine content with the Glaxo mutant and three promising lines evolved elsewhere viz. 'RRL (Bhuhaneswar) Y-14', 'RRL (Jorhat)' and 'Pusa'. The results indicate gainful use of induced mutants in hybridization leading to development of superior less-spiny lines of steroid bearing Solanum viarum

In silico screening of 393 mutants facilitates enzyme engineering of amidase activity in CalB

DEFF Research Database (Denmark)

Hediger, Martin Robert; De Vico, Luca; Rannes, Julie Bille

2013-01-01

Our previously presented method for high throughput computational screening of mutant activity (Hediger et al., 2012) is benchmarked against experimentally measured amidase activity for 22 mutants of Candida antarctica lipase B (CalB). Using an appropriate cutoff criterion for the computed barriers......, the qualitative activity of 15 out of 22 mutants is correctly predicted. The method identifies four of the six most active mutants with ≥3-fold wild type activity and seven out of the eight least active mutants with ≤0.5-fold wild type activity. The method is further used to screen all sterically possible (386......) double-, triple- and quadruple-mutants constructed from the most active single mutants. Based on the benchmark test at least 20 new promising mutants are identified....

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.

The levels of mutant K-RAS and mutant N-RAS are rapidly reduced in a Beclin1 / ATG5 -dependent fashion by the irreversible ERBB1/2/4 inhibitor neratinib.

Science.gov (United States)

Booth, Laurence; Roberts, Jane L; Poklepovic, Andrew; Kirkwood, John; Sander, Cindy; Avogadri-Connors, Francesca; Cutler, Richard E; Lalani, Alshad S; Dent, Paul

2018-02-01

The FDA approved irreversible inhibitor of ERBB1/2/4, neratinib, was recently shown to rapidly down-regulate the expression of ERBB1/2/4 as well as the levels of c-MET and mutant K-RAS via autophagic degradation. In the present studies, in a dose-dependent fashion, neratinib reduced the expression levels of mutant K-RAS or of mutant N-RAS, which was augmented in an additive to greater than additive fashion by the HDAC inhibitors sodium valproate and AR42. Neratinib could reduce PDGFRα levels in GBM cells, that was enhanced by sodium valproate. Knock down of Beclin1 or of ATG5 prevented neratinib and neratinib combined with sodium valproate / AR42 from reducing the expression of mutant N-RAS in established PDX and fresh PDX models of ovarian cancer and melanoma, respectively. Neratinib and the drug combinations caused the co-localization of mutant RAS proteins and ERBB2 with Beclin1 and cathepsin B. The drug combination activated the AMP-dependent protein kinase that was causal in enhancing HMG Co A reductase phosphorylation. Collectively, our data reinforce the concept that the irreversible ERBB1/2/4 inhibitor neratinib has the potential for use in the treatment of tumors expressing mutant RAS proteins.

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.

Functional rescue of mutant ABCA1 proteins by sodium 4-phenylbutyrate.

Science.gov (United States)

Sorrenson, Brie; Suetani, Rachel J; Williams, Michael J A; Bickley, Vivienne M; George, Peter M; Jones, Gregory T; McCormick, Sally P A

2013-01-01

Mutations in the ATP-binding cassette transporter A1 (ABCA1) are a major cause of decreased HDL cholesterol (HDL-C), which infers an increased risk of cardiovascular disease (CVD). Many ABCA1 mutants show impaired localization to the plasma membrane. The aim of this study was to investigate whether the chemical chaperone, sodium 4-phenylbutyrate (4-PBA) could improve cellular localization and function of ABCA1 mutants. Nine different ABCA1 mutants (p.A594T, p.I659V, p.R1068H, p.T1512M, p.Y1767D, p.N1800H, p.R2004K, p.A2028V, p.Q2239N) expressed in HEK293 cells, displaying different degrees of mislocalization to the plasma membrane and discrete impacts on cholesterol efflux, were subject to treatment with 4-PBA. Treatment restored localization to the plasma membrane and increased cholesterol efflux function for the majority of mutants. Treatment with 4-PBA also increased ABCA1 protein expression in all transfected cell lines. In fibroblast cells obtained from low HDL-C subjects expressing two of the ABCA1 mutants (p.R1068H and p.N1800H), 4-PBA increased cholesterol efflux without any increase in ABCA1 expression. Our study is the first to investigate the effect of the chemical chaperone, 4-PBA on ABCA1 and shows that it is capable of restoring plasma membrane localization and enhancing the cholesterol efflux function of mutant ABCA1s both in vitro and ex vivo. These results suggest 4-PBA may warrant further investigation as a potential therapy for increasing cholesterol efflux and HDL-C levels.

Homologous Recombination Defective Arabidopsis Mutants Exhibit Enhanced Sensitivity to Abscisic Acid.

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Sujit Roy

Full Text Available Abscisic acid (ABA acts as an important plant hormone in regulating various aspects of plant growth and developmental processes particularly under abiotic stress conditions. An increased ABA level in plant cells inhibits DNA replication and cell division, causing plant growth retardation. In this study, we have investigated the effects of ABA on the growth responses of some major loss-of-function mutants of DNA double-stand break (DSB repair genes in Arabidopsis during seed germination and early stages of seedling growth for understanding the role of ABA in the induction of genome instability in plants. A comparative analysis of ABA sensitivity of wild-type Arabidopsis and the knockout mutant lines related to DSB sensors, including atatm, atatr, the non-homologous end joining (NHEJ pathway genes, and mutants related to homologous recombination (HR pathway genes showed relatively enhanced sensitivity of atatr and HR-related mutants to ABA treatment. The expression levels of HR-related genes were increased in wild-type Arabidopsis (Col-0 during seed germination and early stages of seedling growth. Immunoblotting experiments detected phosphorylation of histone H2AX in wild-type (Col-0 and DSB repair gene mutants after ABA treatment, indicating the activation of DNA damage response due to ABA treatment. Analyses of DSB repair kinetics using comet assay under neutral condition have revealed comparatively slower DSB repair activity in HR mutants. Overall, our results have provided comprehensive information on the possible effect of ABA on DNA repair machinery in plants and also indicated potential functional involvement of HR pathway in repairing ABA induced DNA damage in Arabidopsis.

Population genetics inference for longitudinally-sampled mutants under strong selection.

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Lacerda, Miguel; Seoighe, Cathal

2014-11-01

Longitudinal allele frequency data are becoming increasingly prevalent. Such samples permit statistical inference of the population genetics parameters that influence the fate of mutant variants. To infer these parameters by maximum likelihood, the mutant frequency is often assumed to evolve according to the Wright-Fisher model. For computational reasons, this discrete model is commonly approximated by a diffusion process that requires the assumption that the forces of natural selection and mutation are weak. This assumption is not always appropriate. For example, mutations that impart drug resistance in pathogens may evolve under strong selective pressure. Here, we present an alternative approximation to the mutant-frequency distribution that does not make any assumptions about the magnitude of selection or mutation and is much more computationally efficient than the standard diffusion approximation. Simulation studies are used to compare the performance of our method to that of the Wright-Fisher and Gaussian diffusion approximations. For large populations, our method is found to provide a much better approximation to the mutant-frequency distribution when selection is strong, while all three methods perform comparably when selection is weak. Importantly, maximum-likelihood estimates of the selection coefficient are severely attenuated when selection is strong under the two diffusion models, but not when our method is used. This is further demonstrated with an application to mutant-frequency data from an experimental study of bacteriophage evolution. We therefore recommend our method for estimating the selection coefficient when the effective population size is too large to utilize the discrete Wright-Fisher model. Copyright © 2014 by the Genetics Society of America.

Characterization of a Thermo-Inducible Chlorophyll-Deficient Mutant in Barley

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Rong Wang

2017-11-01

Full Text Available Leaf color is an important trait for not only controlling crop yield but also monitoring plant status under temperature stress. In this study, a thermo-inducible chlorophyll-deficient mutant, named V-V-Y, was identified from a gamma-radiated population of the barley variety Vlamingh. The leaves of the mutant were green under normal growing temperature but turned yellowish under high temperature in the glasshouse experiment. The ratio of chlorophyll a and chlorophyll b in the mutant declined much faster in the first 7–9 days under heat treatment. The leaves of V-V-Y turned yellowish but took longer to senesce under heat stress in the field experiment. Genetic analysis indicated that a single nuclear gene controlled the mutant trait. The mutant gene (vvy was mapped to the long arm of chromosome 4H between SNP markers 1_0269 and 1_1531 with a genetic distance of 2.2 cM and a physical interval of 9.85 Mb. A QTL for grain yield was mapped to the same interval and explained 10.4% of the yield variation with a LOD score of 4. This QTL is coincident with the vvy gene interval that is responsible for the thermo-inducible chlorophyll-deficient trait. Fine mapping, based on the barley reference genome sequence, further narrowed the vvy gene to a physical interval of 0.428 Mb with 11 annotated genes. This is the first report of fine mapping a thermo-inducible chlorophyll-deficient gene in barley.

Loss of circadian clock accelerates aging in neurodegeneration-prone mutants.

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Krishnan, Natraj; Rakshit, Kuntol; Chow, Eileen S; Wentzell, Jill S; Kretzschmar, Doris; Giebultowicz, Jadwiga M

2012-03-01

Circadian clocks generate rhythms in molecular, cellular, physiological, and behavioral processes. Recent studies suggest that disruption of the clock mechanism accelerates organismal senescence and age-related pathologies in mammals. Impaired circadian rhythms are observed in many neurological diseases; however, it is not clear whether loss of rhythms is the cause or result of neurodegeneration, or both. To address this important question, we examined the effects of circadian disruption in Drosophila melanogaster mutants that display clock-unrelated neurodegenerative phenotypes. We combined a null mutation in the clock gene period (per(01)) that abolishes circadian rhythms, with a hypomorphic mutation in the carbonyl reductase gene sniffer (sni(1)), which displays oxidative stress induced neurodegeneration. We report that disruption of circadian rhythms in sni(1) mutants significantly reduces their lifespan compared to single mutants. Shortened lifespan in double mutants was coupled with accelerated neuronal degeneration evidenced by vacuolization in the adult brain. In addition, per(01)sni(1) flies showed drastically impaired vertical mobility and increased accumulation of carbonylated proteins compared to age-matched single mutant flies. Loss of per function does not affect sni mRNA expression, suggesting that these genes act via independent pathways producing additive effects. Finally, we show that per(01) mutation accelerates the onset of brain pathologies when combined with neurodegeneration-prone mutation in another gene, swiss cheese (sws(1)), which does not operate through the oxidative stress pathway. Taken together, our data suggest that the period gene may be causally involved in neuroprotective pathways in aging Drosophila. Copyright © 2011 Elsevier Inc. All rights reserved.

Isolation of L-methionine-enriched mutant of a methylotrophic yeast, Candida boidinii No.2201

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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

Variation of root system characters in collection of semi-dwarf spring barley mutants

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Nawrot, M.; Zbieszczyk, J.; Maluszynski, M.

2000-01-01

The collection of 371 semi-dwarf mutants, derived from 12 spring barley varieties has been used as material for analysis of root system. The mutants have been obtained after mutagenic treatment with N-methyl-N-nitroso urea (MNH), sodium azide (NaN3), gamma-rays and fast neutrons. The following analysis of root system were performed: seminal root growth of 8-day old seedlings, seminal and adventitious root growth of 6-week old plants and dynamics of root growth during first 6 weeks of plant growth. Seminal root length, root number and the length of the first leaf in barley mutants were investigated with the use of paper rollers. Root system analysis of 6-week old plants was performed on genotypes grown in PVC tubes filled with sand, supplemented with 1 mineral salts of MS medium. The following measurements were made: the length of the longest seminal root and the longest adventitious root, the number of adventitious roots and the number of tillers. Analysis of dynamics of root growth during the first six weeks of vegetation was performed at the end of each 7-day growth period in the PVC tubes filled with sand. Great variability in the seminal root length was found in analysed 8-day old seedling population. Almost half of the analysed mutants showed significant root length reduction, but about ten percent of semi-dwarf mutants developed roots with an increased length in comparison to parents. No significant differences were found between analysed mutants and corresponding parent varieties regarding the number of seminal roots. After six weeks of growth, the selected mutants showed differences in the reduction of root length in comparison to the 8-day old seedlings. The results of root growth dynamics indicated that analysed mutants had different patterns in comparison to the parent variety. Differences in the growth dynamics were also observed among the parent varieties. The observed differences in pattern of root growth between mutants and corresponding parents

Calreticulin mutants in mice induce an MPL-dependent thrombocytosis with frequent progression to myelofibrosis.

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Marty, Caroline; Pecquet, Christian; Nivarthi, Harini; El-Khoury, Mira; Chachoua, Ilyas; Tulliez, Micheline; Villeval, Jean-Luc; Raslova, Hana; Kralovics, Robert; Constantinescu, Stefan N; Plo, Isabelle; Vainchenker, William

2016-03-10

Frameshift mutations in the calreticulin (CALR) gene are seen in about 30% of essential thrombocythemia and myelofibrosis patients. To address the contribution of the CALR mutants to the pathogenesis of myeloproliferative neoplasms, we engrafted lethally irradiated recipient mice with bone marrow cells transduced with retroviruses expressing these mutants. In contrast to wild-type CALR, CALRdel52 (type I) and, to a lesser extent, CALRins5 (type II) induced thrombocytosis due to a megakaryocyte (MK) hyperplasia. Disease was transplantable into secondary recipients. After 6 months, CALRdel52-, in contrast to rare CALRins5-, transduced mice developed a myelofibrosis associated with a splenomegaly and a marked osteosclerosis. Monitoring of virus-transduced populations indicated that CALRdel52 leads to expansion at earlier stages of hematopoiesis than CALRins5. However, both mutants still specifically amplified the MK lineage and platelet production. Moreover, a mutant deleted of the entire exon 9 (CALRdelex9) did not induce a disease, suggesting that the oncogenic property of CALR mutants was related to the new C-terminus peptide. To understand how the CALR mutants target the MK lineage, we used a cell-line model and demonstrated that the CALR mutants, but not CALRdelex9, specifically activate the thrombopoietin (TPO) receptor (MPL) to induce constitutive activation of Janus kinase 2 and signal transducer and activator of transcription 5/3/1. We confirmed in c-mpl- and tpo-deficient mice that expression of Mpl, but not of Tpo, was essential for the CALR mutants to induce thrombocytosis in vivo, although Tpo contributes to disease penetrance. Thus, CALR mutants are sufficient to induce thrombocytosis through MPL activation. © 2016 by The American Society of Hematology.

Probiotic features of Lactobacillus plantarum mutant strains.

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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.

Apoc2 loss-of-function zebrafish mutant as a genetic model of hyperlipidemia

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Chao Liu

2015-08-01

Full Text Available Apolipoprotein C-II (APOC2 is an obligatory activator of lipoprotein lipase. Human patients with APOC2 deficiency display severe hypertriglyceridemia while consuming a normal diet, often manifesting xanthomas, lipemia retinalis and pancreatitis. Hypertriglyceridemia is also an important risk factor for development of cardiovascular disease. Animal models to study hypertriglyceridemia are limited, with no Apoc2-knockout mouse reported. To develop a genetic model of hypertriglyceridemia, we generated an apoc2 mutant zebrafish characterized by the loss of Apoc2 function. apoc2 mutants show decreased plasma lipase activity and display chylomicronemia and severe hypertriglyceridemia, which closely resemble the phenotype observed in human patients with APOC2 deficiency. The hypertriglyceridemia in apoc2 mutants is rescued by injection of plasma from wild-type zebrafish or by injection of a human APOC2 mimetic peptide. Consistent with a previous report of a transient apoc2 knockdown, apoc2 mutant larvae have a minor delay in yolk consumption and angiogenesis. Furthermore, apoc2 mutants fed a normal diet accumulate lipid and lipid-laden macrophages in the vasculature, which resemble early events in the development of human atherosclerotic lesions. In addition, apoc2 mutant embryos show ectopic overgrowth of pancreas. Taken together, our data suggest that the apoc2 mutant zebrafish is a robust and versatile animal model to study hypertriglyceridemia and the mechanisms involved in the pathogenesis of associated human diseases.

Fontes de resistência em acessos de Solanum (secção Lycopersicon a Verticillium dahliae raças 1 e 2 Sources of resistance to Verticillium dahliae races 1 and 2 in accessions of Solanum (section Lycopersicon

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Bruno Eduardo C de Miranda

2010-12-01

Full Text Available A murcha-de-verticílio (Verticillium dahliae é uma das doenças mais severas do tomateiro (Solanum lycopersicum L.. Duas raças fisiológicas de V. dahliae foram caracterizadas infectando o tomateiro e ambas estão presentes no Brasil. A estratégia de controle mais efetiva para isolados da raça 1 tem sido a utilização de cultivares resistentes em associação com práticas culturais. Entretanto, não existem cultivares comerciais de tomate resistentes à raça 2 do patógeno. Neste contexto, torna-se importante a identificação de novas fontes de resistência que sejam efetivas contra as duas raças de V. dahliae. Buscou-se fontes de resistência a isolados de V. dahliae (raças 1 e 2. Cem acessos de uma coleção de germoplasma contendo espécies cultivadas e selvagens de Solanum (secção Lycopersicon foram inicialmente inoculados pelo método de imersão de raízes com um isolado de V. dahliae raça 1 (5 mL de uma suspensão de 10(6 conídios/mL em condições de casa de vegetação. A avaliação foi feita aos 30 dias após a inoculação, usando uma escala de notas variando de 1 (planta sadia a 5 (planta morta. Foram considerados resistentes os acessos que apresentaram nota média entre 1 e 2. Um grupo composto por 38 acessos classificados como resistentes neste primeiro ensaio foi reavaliado para resistência a outros quatro isolados de V. dahliae pertencentes às raças 1 e 2. As cultivares Ponderosa e Floradade foram utilizadas como controles. O ensaio foi conduzido em casa de vegetação em delineamento experimental de blocos ao acaso em arranjo fatorial 5 x 40, com três repetições (vasos com quatro plantas. A avaliação foi feita baseada nos parâmetros epidemiológicos: período de incubação e índice de doença. Foram identificados acessos com resistência raça-específica e também com resistência a ambas as raças. Estes acessos podem ser indicados para futuros programas de melhoramento genético visando incorporar

Homologous series of induced early mutants in Indica rice. Pt.3: The relationship between the induction of homologous series of early mutants and its different pedigree

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

2002-01-01

The percentage of homologous series of early mutants (PHSEM) induced by irradiation was closely related to its pedigree. This study showed that PHSEM for varieties with the same pedigree were similar, and there were three different level of dominance (high, low and normal) in the homologous series induced from different pedigree. The PHSEM for varieties derived form distant-relative-parents were higher than that derived from close-relative-parents. There was the dominance pedigree for the induction of homologous series of early mutants. IR8(Peta x DGWG), IR127 (Cpslo x Sigadis) and IR24 (IR8 x IR127) were dominant pedigree, and varieties derived from them could be easily induced the homologous series of early mutants

MUTANTES DE LARANJA - 'PÊRA' COM NÚMERO REDUZIDO DE SEMENTES, OBTIDOS ATRAVÉS DE MUTAÇÕES INDUZIDAS SWEET ORANGE 'PÊRA' MUTANTS WITH LOW NUMBER OF SEEDS OBTAINED THROUGH MUTATION INDUCTION

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RODRIGO ROCHA LATADO

2001-08-01

Full Text Available A obtenção de cultivares de citros com pequeno número de sementes é importante quando o objetivo é a produção de frutas para o consumo in natura. O objetivo deste trabalho foi o de avaliar, por três anos (1997, 1998 e 1999, o número médio de sementes e 15 outras características agronômicas, de 127 mutantes putativos de laranja-'Pêra', selecionados após irradiação de borbulhas com raios-gama e 8 plantas selecionadas do controle não irradiado. Os mutantes foram divididos em 16 grupos baseados nos tipos de mutações observados e em cada grupo, como controle comum, foram incluídas plantas de laranja-'Pêra' comercial. Observou-se que 46 mutantes putativos e uma planta do controle não irradiado (PSC apresentaram redução significativa no número de sementes por fruto, nos três anos consecutivos, sendo que 15 mutantes apresentaram frutos com média entre uma e duas sementes e 9 mutantes, frutos com média inferior a uma semente. Dentre estes 9 mutantes, os de número 27, 28 e 58, que apresentaram também alterações significativas no diâmetro de copa ou na altura de planta, além do 59 e 101, que não apresentaram alterações nas outras 15 características avaliadas, possuem um maior potencial para serem lançados como novos mutantes de laranja-'Pêra' com pequeno número de sementes.Citrus varieties with low number of seeds are important for in natura fruit market. The objective of the present work was to evaluate, for three years (1997, 1998 and 1999, the average number of seeds per fruit and 15 other agronomic characteristics of 127 putative mutated clones of sweet orange 'Pêra', selected after gamma-irradiation of budwood and 8 non irradiated control clones. Mutants were divided in 16 groups based on the type of mutation observed 'Pêra' commercial control plants (PCC were included. It was observed that 46 putative mutants and one non-irradiated plant (PSC showed significant reduction in seed number per fruit. Fifteen

Photosynthetic Characteristics of Flag Leaves in Rice White Stripe Mutant 6001 During Senescence Process

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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.

Ensemble-based computational approach discriminates functional activity of p53 cancer and rescue mutants.

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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.

Nonsense mutants in the bacteriophage T4D v gene

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