Polygenic systems controlling the expression of major mutant genes which affect chaeta number in Drosophila melanogaster

Cocks, Betty

doi:10.1038/hdy.1954.2

Cited by 6 publications

(4 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Certainly pyd v and at least some of the extra bristle polygenes manifest in sc+ are being expressed in suppressed ScI and since we know that the polygenes affecting scI are largely distinct from those affecting sc+ (Haskell 1943;Cocks 1954;Lee and Fraser 1969), it would appear from the suppressed scI array (Fig. 1) that yet other specific modifiers of su(Hw) 2 are operative.…”

Section: Discussionmentioning

confidence: 99%

“…Substitution of major mutant alleles has the effect of changing this spectrum of quantitative variation (Haskell 1943;Cocks 1954) suggesting that polygenic modifiers are primarily posttranslational, since genes affecting transcription or translation would be expected to affect both mutants and their wild-type alleles similarly (Lee and Fraser 1969). Fraser, Erway, and Brenton (1968) have proposed that 8C 1 acts as a switch gene activating a wholly new constellation of polygenes, while Rendel (1959) claims that while the polygenes affecting 8C 1 are active in the presence of 8C+ the magnitude of their effects is considerably reduced by the canalized nature of the system, due to the presence of 8C+ and independent of mean bristle number.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Phenogenetics of A Super-Suppressor in Drosophila Melanogaster I. Phenotypic Characterization and Suppressor Efficiency

Gl¹

1970

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

SummaryAn investigation of the phenotypic characteristics of the super-suppressor Bu(Hw)2 of D. melanogaster was carried out using the suppressible mutant sc1 together with the scutellar, dorsocentral, and vertical bristle systems. The effect of the suppressor was studied in a series of selection lines differing in both their sc1 and sc+ means.The suppressor was found to be highly efficient and sensitive to genetic background but insensitive to temperature, developmental rate, and heterochromatin. It would appear that Bu(Hw)2 behaves as a complete recessive in all cases but this was only established definitely for the quantifiable mutant sc1• The absence of the femalespecific characteristics of su(Hw)2 in males was found not to be due to the presence of the Y -chromosome. There was a great similarity between suppressed mutant and wildtype phenotypes which was particularly apparent in the bristle class distributions.The data are not seen as compatible with the idea that the su(Hw)2 locus is normally a structural gene for t-RNA although the possibility that the translational machinery is in some way involved is very strong.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Phenogenetics of A Super-Suppressor in Drosophila Melanogaster I. Phenotypic Characterization and Suppressor Efficiency

Gl¹

1970

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

show abstract

“…Nearly all the genetic variability in the sc homozygote popUlation would then come from ordinary additive genes, while the coefficients of determination (;'2) in Table 4 would indicate the proportion of genetic variability in the heterozygote population due to the ordinary genes, the rest being due to the modifiers of the heterozygote. Cocks (1954) gave 0·85 as an estimate of the coefficient of determination for abdominal bristle number between the wild type and the sc hemizygote of various populations. Although her estimate is not directly comparable to ours, both at least indicate the presence of genetic variability dependent on the scute genotype.…”

Section: Discussionmentioning

confidence: 99%

Correlated Responses of Different scute Genotypes to Long-term Selection for Increased Abdominal Bristle Number in Drosophila melanogaster

Yoo¹

1974

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

The first dose effect of sc+ has been measured for abdominal bristle number in six replicate lines of D. melanogaster being selected upward for this character in the sc homo-and hemizygote. The within-line regression coefficient of the heterozygote on the sc homozygote showed considerable variation among the lines with a range of 0-47-1' 22, indicating the dependence of gene action on genetic background. But, on the average, the effect of sc+ was approximately additive for abdominal bristle number. From this average, the genetic correlation in the base population between the two genotypes was estimated to be considerably less than unity, which suggests some genetic variability that is dependent on the genotype of the major locus. A similar relationship was also obtained for the two male hemizygotes.The sc+ homozygote as well as the above genotypes were scored for abdominal and scutellar bristle number near the end of long-continued selection and the degree of dominance of sc+ over sc assessed for each character. For abdominal bristle number, the degree of dominance was not altered significantly except in one line (Ua), where sc increased the bristle number in females only and was dominant ove~ sc+; the degree of dominance was apparently lowered for scutellar bristle number in all the lines, probably because selection had pulled the sc+ homozygote and the heterozygote out of the four-bristle canalized zone.Scutellar bristle number showed positive correlated response for all scute genotypes in each line except in Ua, but, when the five lines are compared, the relative amount of correlated response in one genotype does not necessarily correspond to that in another, suggesting interaction between the scute locus and genetic background for scutellar bristle number, at least in some lines.

show abstract

“…The continuous variation in bristle number in the expression of scute in D. melanogaster is known to be sensitive to differences in modifying genes (HASKELL, 1943 andCOCKS, 1954) and to environmental factors ( PLUNKETT, 1926 andIVES, 1939). Thus it would be desirable to study the scute effect in isogenic stocks and at constant temperature.…”

mentioning

confidence: 99%

Variation in the Manifestation of the Scute Mutation in Different Strains of Drosophila Funebris

Perje

1955

Acta Zoologica

View full text Add to dashboard Cite

Polygenic systems controlling the expression of major mutant genes which affect chaeta number in Drosophila melanogaster

Cited by 6 publications

References 7 publications

The Phenogenetics of A Super-Suppressor in Drosophila Melanogaster I. Phenotypic Characterization and Suppressor Efficiency

The Phenogenetics of A Super-Suppressor in Drosophila Melanogaster I. Phenotypic Characterization and Suppressor Efficiency

Correlated Responses of Different scute Genotypes to Long-term Selection for Increased Abdominal Bristle Number in Drosophila melanogaster

Variation in the Manifestation of the Scute Mutation in Different Strains of Drosophila Funebris

Contact Info

Product

Resources

About