Quantitative Genetics of Drosophila Melanogaster. II. Heritabilities and Genetic Correlations between Sexes for Head and Thorax Traits.

Abstract A quantitative genetic analysis is reported for traits on the head and thorax of adult fruit flies, Drosophila melanogaster. Females are larger than males, and the magnitude of sexual dimorphism is similar for traits derived from the same imaginal disc, but the level of sexual dimorphism varies widely across discs. The greatest difference between males and females occurs for the dimensions of the sclerotized mouthparts of the proboscis. Most of the traits studied are highly heritable with heritabilities ranging from 0.26 to 0.84 for males and 0.27 to 0.81 for females. In general, heritabilities are slightly higher for males, possibly reflecting the effect of dosage compensation on X-linked variance. The X chromosome contributes substantially to variance for many of these traits, and including results reported elsewhere, the variance for over two-thirds of the traits studied includes X-linked variance. The genetic correlations between sexes for the same trait are generally high and close to unity. Coupled with the small differences in the traits between sexes for heritabilities and phenotypic variances, these results suggest that selection would be very slow to change the level of sexual dimorphism in size of various body parts.

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QUANTITATIVE GENETICS OF DROSOPHILA MELANOGASTER. I. SEXUAL DIMORPHISM IN GENETIC PARAMETERS FOR WING TRAITS

Genetics ◽

10.1093/genetics/114.2.549 ◽

1986 ◽

Vol 114 (2) ◽

pp. 549-566

Author(s):

David E Cowley ◽

William R Atchley ◽

J J Rutledge

Keyword(s):

Drosophila Melanogaster ◽

Sexual Dimorphism ◽

Dosage Compensation ◽

Genetic Parameters ◽

Genetic Model ◽

Genetic Correlations ◽

Error Variance ◽

Minor Effect ◽

Phenotypic Variance ◽

Environmental Variance

ABSTRACT Sexual dimorphism in genetic parameters is examined for wing dimensions of Drosophila melanogaster. Data are fit to a quantitative genetic model where phenotypic variance is a linear function of additive genetic autosomal variance (common to both sexes), additive genetic X-linked variances distinct for each sex, variance due to common rearing environment of families, residual environmental variance, random error variance due to replication, and variance due to measurement error and developmental asymmetry (left vs. right sides). Polygenic dosage compensation and its effect on genetic variances and covariances between sexes is discussed. Variance estimates for wing length and other wing dimensions highly correlated with length support the hypothesis that the Drosophila system of dosage compensation will cause male X-linked genetic variance to be substantially larger than female X-linked variance. Results for various wing dimensions differ, suggesting that the level of dosage compensation may differ for different traits. Genetic correlations between sexes for the same trait are presented. Total additive genetic correlations are near unity for most wing traits; this indicates that selection in the same direction in both sexes would have a minor effect on changing the magnitude of difference between sexes. Additive X-linked correlations suggest some genotype × sex interactions for X-linked effects.

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DOSAGE COMPENSATION OF SERINE-4 TRANSFER RNA IN DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/102.3.525 ◽

1982 ◽

Vol 102 (3) ◽

pp. 525-537

Author(s):

James A Birchler ◽

R Keith Owenby ◽

K Bruce Jacobson

Keyword(s):

Drosophila Melanogaster ◽

X Chromosome ◽

Dosage Compensation ◽

Transfer Rna ◽

Dosage Effect ◽

Rna Expression ◽

Structural Locus ◽

Relative Expression ◽

Total Female ◽

Males And Females

ABSTRACT A dosage series of the X chromosome site for serine-4 transfer RNA consisting of one of three copies in females and one to two in males was constructed to test whether transfer RNA expression is governed by dosage compensation. A dosage effect on the level of the serine-4 isoacceptor was observed in both females and males when the structural locus was varied. However, in males, each dose had a relatively greater expression so the normal one dose was slightly greater than the total female value and the duplicated male had the highest relative expression of all the types examined. Serine-4 levels in males and females from an isogenic Oregon-R stock were similar. Thus the transfer RNA levels conform to the expectations of dosage compensation.

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Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽

10.1093/genetics/143.1.353 ◽

1996 ◽

Vol 143 (1) ◽

pp. 353-364 ◽

Cited By ~ 3

Author(s):

Jerry A Coyne

Keyword(s):

Drosophila Melanogaster ◽

Sexual Dimorphism ◽

Genetic Analysis ◽

Species Difference ◽

The Other ◽

Chromosome 3 ◽

Apparent Effect ◽

The Third ◽

Hydrocarbon Profile ◽

The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

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A quantitative genetic study of starvation resistance at different geographic scales in natural populations of Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672310000327 ◽

2010 ◽

Vol 92 (4) ◽

pp. 253-259 ◽

Cited By ~ 12

Author(s):

JULIETA GOENAGA ◽

JUAN JOSÉ FANARA ◽

ESTEBAN HASSON

Keyword(s):

Drosophila Melanogaster ◽

Genetic Correlations ◽

Natural Populations ◽

Food Shortage ◽

Population Variation ◽

Phenotypic Variance ◽

Starvation Resistance ◽

Natural Genetic Variation ◽

Quantitative Genetic ◽

Variation Explained

SummaryFood shortage is a stress factor that commonly affects organisms in nature. Resistance to food shortage or starvation resistance (SR) is a complex quantitative trait with direct implications on fitness. However, surveys of natural genetic variation in SR at different geographic scales are scarce. Here, we have measured variation in SR in sets of lines derived from nine natural populations of Drosophila melanogaster collected in western Argentina. Our study shows that within population variation explained a larger proportion of overall phenotypic variance (80%) than among populations (7·2%). We also noticed that an important fraction of variation was sex-specific. Overall females were more resistant to starvation than males; however, the magnitude of the sexual dimorphism (SD) in SR varied among lines and explained a significant fraction of phenotypic variance in all populations. Estimates of cross-sex genetic correlations suggest that the genetic architecture of SR is only partially shared between sexes in the populations examined, thus, facilitating further evolution of the SD.

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Quantitative genetic analysis of natural variation in body size in Drosophila melanogaster

Heredity ◽

10.1038/sj.hdy.6800121 ◽

2002 ◽

Vol 89 (2) ◽

pp. 145-153 ◽

Cited By ~ 58

Author(s):

J Gockel ◽

S J W Robinson ◽

W J Kennington ◽

D B Goldstein ◽

L Partridge

Keyword(s):

Drosophila Melanogaster ◽

Body Size ◽

Genetic Analysis ◽

Natural Variation ◽

Quantitative Genetic ◽

Quantitative Genetic Analysis

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Expression of cis-regulatory mutations of the white locus in metafemales of Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672300030123 ◽

1992 ◽

Vol 59 (1) ◽

pp. 11-18 ◽

Cited By ~ 17

Author(s):

James A. Birchler

Keyword(s):

X Chromosome ◽

Dosage Compensation ◽

Phenotypic Expression ◽

Inverse Correlation ◽

Basic Mechanism ◽

Altered Expression ◽

Regulatory Mutations ◽

Sexually Dimorphic Expression ◽

White Locus ◽

Males And Females

SummaryAt the white eye colour locus, there are a number of alleles that have altered expression between males and females. To test these regulatory mutations of the white eye colour locus for their phenotypic expression in metafemales (3X; 2A) compared to diploid females and males, eleven alleles or transduced copies of white were analysed. Two alleles that exhibit dosage compensation between males and females (apricot, blood) also exhibit dosage compensation in metafemales. White-ivory and white-eosin, which fail to dosage compensate in males compared to females, but that are distinct physical lesions, also show a dosage effect in metafemales. Two alleles with greater expression in males than females (spotted, spotted-55) exhibit even lower expression in metafemales. Lastly, five transduced copies of white carrying three different lengths of the white promoter, but that all exhibit higher expression in males, show reduced expression in metafemales, exhibiting an inverse correlation between the level of expression and the dosage of the X chromosome. Because these alleles of white respond to dosage compensation in metafemales as a continuum of the male and female responses, it is concluded that the same basic mechanism of dosage compensation is involved and that the dosage of the X chromosome conditions the sexually dimorphic expression.

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Genetic analysis of the sexual dimorphism of glass in Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672300026331 ◽

1984 ◽

Vol 44 (2) ◽

pp. 125-132 ◽

Cited By ~ 3

Author(s):

James A. Birchler

Keyword(s):

Drosophila Melanogaster ◽

Sexual Dimorphism ◽

Genetic Analysis ◽

Phenotypic Expression ◽

Sexually Dimorphic ◽

Modifier Locus ◽

The Third ◽

Specific Manner ◽

Gene Maps ◽

Insertional Translocation

SUMMARYA modifier locus is described that alters the level of phenotypic expression of the third chromosome mutant glass in a sex specific manner. Alternative alleles either confer a sexually dimorphic level of pigment in glass mutants, with the male being greater, or cause similar expression in the two sexes. The alleles are indistinguishable in females but produce the respective phenotypes in males. The gene maps to the tip of the X chromosome at position 0·96 ± 0·11. Cytologically, the locus is present between polytene bands 3A6–8 and 3C2–3 as determined by its inclusion in translocated X segments in w + Y, Dp(l;2)w70h31 and Dp(l;3)w67k27 The dimorphic allele is dominant to the nondimorphic condition in males heterozygous for an insertional translocation carrying the dimorphic allele and a normal chromosome carrying the nondimorphic form. The dimorphic allele in two doses in males does not exhibit a dosage effect. The modifier phenotype is unaffected in two X flies by the presence of the transformer mutation.

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Chromosomal basis of dosage compensation in Drosophila: I. Cellular autonomy of hyperactivity of the male X-chromosome in salivary glands and sex differentiation

Genetics Research ◽

10.1017/s001667230000197x ◽

1969 ◽

Vol 14 (2) ◽

pp. 137-150 ◽

Cited By ~ 43

Author(s):

S. C. Lakhotia ◽

A. S. Mukherjee

Keyword(s):

Drosophila Melanogaster ◽

Salivary Glands ◽

X Chromosome ◽

Metabolic Activity ◽

Dosage Compensation ◽

Rna Synthesis ◽

Sex Differentiation ◽

Chromosome 3 ◽

Normal Male ◽

Developmental Physiology

Morphology and the rate of RNA synthesis of the X-chromosome in XX/XO mosaic larval salivary glands of Drosophila melanogaster have been examined. For this purpose the unstable ring-X was utilized to produce XX and XO nuclei in the same pair of glands. The width of the X-chromosome and the left arm of the 3rd chromosome (3L) of larval salivary glands was measured and the rate of RNA synthesis by them was studied upon the use of [3H]uridine autoradiography in such XX (female) and XO (male) nuclei developing in a female background (i.e. otherwise genotypically XX). In such mosaic glands the width of the single X-chromosome of male nuclei is nearly as great as that of the paired two X's of female nuclei, as is also the case in normal male (X Y) and female (XX). The single X of male nuclei synthesizes RNA at a rate equal to that of the paired two X's of female nuclei and nearly twice that of an unpaired X of XX nuclei. Neither the developmental physiology of the sex nor the proportion of XO nuclei in a pair of mosaic salivary glands of an XX larva has any influence on these two characteristics of the male X-chromosome.It is suggested that dosage compensation in Drosophila is achieved chiefly, if not fully, by a hyperactivity of the male X, in contrast to the single X inactivation in female mammals, that this hyperactivity of the male X is expressed visibly in the morphology and metabolic activity of the X-chromosome in the larval salivary glands of the male, and that this hyperactivity and therefore dosage compensation in Drosophila in general is not dependent on sex-differentiation, but is a function of the doses of the X-chromosome itself.

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Drosophila CLAMP is an essential protein with sex-specific roles in males and females

10.1101/042820 ◽

2016 ◽

Author(s):

Jennifer A. Urban ◽

Caroline A. Doherty ◽

William T. Jordan ◽

Jacob E. Bliss ◽

Jessica Feng ◽

...

Keyword(s):

X Chromosome ◽

Dosage Compensation ◽

Zinc Finger Protein ◽

Pericentric Heterochromatin ◽

Single Male ◽

Essential Protein ◽

Msl Complex ◽

Males And Females ◽

Male Specific

AbstractDosage compensation is a fundamental mechanism in many species that corrects for the inherent imbalance in X-chromosome copy number between XY males and XX females. In Drosophila melanogaster, transcriptional output from the single male X-chromosome is equalized to that of XX females by recruitment of the Male Specific Lethal (MSL) complex to specific sequences along the length of the X-chromosome. The initial recruitment of MSL complex to the X-chromosome is dependent on a recently discovered zinc finger protein called Chromatin-Linked Adapter for MSL Proteins (CLAMP). However, further studies on the in vivo function of CLAMP remained difficult because the location of the gene in pericentric heterochromatin made it challenging to create null mutations or deficiencies. Using the CRISPR/Cas9 genome editing system, we generated the first null mutant in the clamp gene that eliminates expression of CLAMP protein. We show that CLAMP is necessary for both male and female viability. While females die at the third instar larval stage, males die earlier, likely due to the essential role of CLAMP in male dosage compensation. Moreover, we demonstrate that CLAMP promotes dosage compensation in males and represses key male-specific transcripts involved in sex-determination in females. Our results reveal that CLAMP is an essential protein with dual roles in males and females, which together assure that dosage compensation is a sex-specific process.

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COMPLEMENTATION ANALYSIS OF LATE LETHAL MUTANTS OF DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/77.1.115 ◽

1974 ◽

Vol 77 (1) ◽

pp. 115-125

Author(s):

Allen Shearn

Keyword(s):

Drosophila Melanogaster ◽

Genetic Analysis ◽

Larval Development ◽

Imaginal Disc ◽

Lethal Mutation ◽

Complementation Analysis ◽

Group Of Seven ◽

Gene Functions ◽

Map Location

ABSTRACT Late larval and pupal lethal mutants of Drosophila define those gene functions which are essential for the development of pupae (metamorphosis) but not for embryonic or larval development. In a previous report the isolation of a large number of such mutants was outlined, and a description of the imaginal disc defects in those mutants was described. This report concerns genetic analysis of those mutants. 3746 different pairwise combinations of mutants have been tested for complementation. Only 10 pairs fail to complement. In all of the cases tested, the lethal mutation in each member of a non-complementing pair has a similar map location. In addition to the non-complementing pairs one group of seven partially-complementing mutants has been identified. Comparisons of the imaginal disc defects within the non-complementing pairs and the lethal hybrids formed by the respective pairs were made to test for uniformity of phenotype. No significant qualitative differences were detected between any non-complementing pairs or their respective hybrids.

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