scholarly journals Genetic and maternal variation for heat resistance in Drosophila from the field.

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 783-789 ◽  
Author(s):  
N L Jenkins ◽  
A A Hoffmann
Keyword(s):  
Drosophila Melanogaster ◽  
Body Size ◽  
Heat Resistance ◽  
Maternal Effects ◽  
Maternal Effect ◽  
Morphological Traits ◽  
Wing Length ◽  
Regression Coefficients ◽  
Physiological Trait ◽  
Heritable Variation

Abstract In Drosophila, field heritability estimates have focused on morphological traits and ignored maternal effects. This study considers heritable variation and maternal effects in a physiological trait, heat resistance. Drosophila were collected from the field in Melbourne, Australia. Resistance was determined using knock-down time at 37 degrees. Drosophila melanogaster was more resistant than Drosophila simulans, and males tended to be more resistant than females. Field heritability and maternal effects were examined in D. simulans using the regression of laboratory-reared F1 and F2 onto field-collected parents. Males from the field were crossed to a laboratory stock to obtain progeny. The additive genetic component to variation in heat resistance was large and significant, and heritability was estimated to be around 0.5. A large maternal effect was also evident. Comparisons of regression coefficients suggested that the maternal effect was not associated with cytoplasmic factors. There was no correlation between body size (as measured by wing length) and heat resistance. Unlike in the case of morphological traits, the heritability for heat resistance in nature is not less than that measured in the laboratory.

scholarly journals Temporal uniformity of the spontaneous mutational variance of quantitative traits in Drosophila melanogaster

2000 ◽  
Vol 75 (1) ◽  
pp. 47-51 ◽  
Author(s):  
AURORA GARCÍA-DORADO ◽  
JESUS FERNÁNDEZ ◽  
CARLOS LÓPEZ-FANJUL
Keyword(s):  
Drosophila Melanogaster ◽  
Morphological Traits ◽  
Quantitative Traits ◽  
Wing Length ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
Bristle Number ◽  
Sib Mating ◽  
Mutational Variance ◽  
Interaction Variance

Spontaneous mutations were allowed to accumulate over 209 generations in more than 100 lines, all of them independently derived from a completely homozygous population of Drosophila melanogaster and subsequently maintained under strong inbreeding (equivalent to full-sib mating). Traits scored were: abdominal (AB) and sternopleural (ST) bristle number, wing length (WL) and egg-to-adult viability (V). On two occasions – early (generations 93–122) and late (generations 169–209) – ANOVA estimates of the mutational variance and the mutational line × generation interaction variance were obtained. Mutational heritabilities of morphological traits ranged from 2 × 10−4 to 2 × 10−3 and the mutational coefficient of variation of viability was 0·01. For AB, WL and V, temporal uniformity of the mutational variance was observed. However, a fluctuation of the mutational heritability of ST was detected and could be ascribed to random genotype × environment interaction.

scholarly journals The tumorous-head-1 Locus Affects Bristle Number of the Drosophila melanogaster Cuticle

Genetics ◽  
1998 ◽  
Vol 148 (2) ◽  
pp. 743-752
Author(s):  
G Packert ◽  
D T Kuhn
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effects ◽  
X Chromosome ◽  
Maternal Effect ◽  
Side Effect ◽  
Adult Offspring ◽  
Bithorax Complex ◽  
Naturally Occurring ◽  
Bristle Number ◽  
Lethal Genes

Abstract The tuh-1 maternal effect locus contains two naturally occurring isoalleles, tuh-1h and tuh-1g. Until recently there has been no possibility to distinguish between the tuh-1h and the tuh-1g maternal effects other than evaluating their effect on the Bithorax-Complex (BX-C) Abdominal B (Abd-B) mutant tuh-3. However, in this report we identify a bristle phenotype associated with the tuh-1 locus that has very interesting evolutionary implications. Females homozygous for tuh-1h always produce adult offspring with more bristles than females homozygous or heterozygous for tuh-1g. The effect is global. Increased bristle number occurs in the head, the thorax, and the anterior and posterior abdomen. Females totally deficient for the tuh-1 gene produce offspring with high bristle number. Thus, the bristle phenotype results from the absence of the maternally contributed tuh-1g factor. Genetic evidence shows that the bristle phenotype is caused by the tuh-1 locus and that tuh-1h is completely recessive to tuh-1g. The tuh-1 locus is located at the euchromatin-β-heterochromatin junction near the centromere of the X chromosome and deficiency analysis places the locus between the lethal genes extra organs (eo) and lethal B20 (lB20). The variance in bristle number attributable to the tuh-1 locus in nature is approximately 10.1%, an indication that the bristle phenotype is most likely a neutral, pleiotrophic side effect of tuh-1.

scholarly journals Response of Two Heat Shock Genes to Selection for Knockdown Heat Resistance in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1615-1627 ◽  
Author(s):  
Gawain McColl ◽  
Ary A Hoffmann ◽  
Stephen W McKechnie
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Resistance ◽  
Dna Sequences ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Allelic Variation ◽  
Epistatic Effect ◽  
Frequency Change ◽  
Heritable Variation ◽  
Gene Effects ◽  
Stress Genes

Abstract To identify genes involved in stress resistance and heat hardening, replicate lines of Drosophila melanogaster were selected for increased resistance to knockdown by a 39° heat stress. Two selective regimes were used, one with and one without prior hardening. Mean knockdown times were increased from ~5 min to >20 min after 18 generations. Initial realized heritabilities were as high as 10% for lines selected without hardening, and crosses between lines indicated simple additive gene effects for the selected phenotypes. To survey allelic variation and correlated selection responses in two candidate stress genes, hsr-omega and hsp68, we applied denaturing gradient gel electrophoresis to amplified DNA sequences from small regions of these genes. After eight generations of selection, allele frequencies at both loci showed correlated responses for selection following hardening, but not without hardening. The hardening process itself was associated with a hsp68 frequency change in the opposite direction to that associated with selection that followed hardening. These stress loci are closely linked on chromosome III, and the hardening selection established a disequilibrium, suggesting an epistatic effect on resistance. The data indicate that molecular variation in both hsr-omega and hsp68 contribute to natural heritable variation for hardened heat resistance.

scholarly journals A Comparison of the Genetic Basis of Wing Size Divergence in Three Parallel Body Size Clines of Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 1775-1787 ◽  
Author(s):  
A Stuart Gilchrist ◽  
Linda Partridge
Keyword(s):  
Drosophila Melanogaster ◽  
Body Size ◽  
Maternal Effects ◽  
Wing Size ◽  
Dominance Model ◽  
Additive Variance ◽  
Variance Model ◽  
Generation Means ◽  
Parallel Body ◽  
Linkage Effects

Abstract Body size clines in Drosophila melanogaster have been documented in both Australia and South America, and may exist in Southern Africa. We crossed flies from the northern and southern ends of each of these clines to produce F1, F2, and first backcross generations. Our analysis of generation means for wing area and wing length produced estimates of the additive, dominance, epistatic, and maternal effects underlying divergence within each cline. For both females and males of all three clines, the generation means were adequately described by these parameters, indicating that linkage and higher order interactions did not contribute significantly to wing size divergence. Marked differences were apparent between the clines in the occurrence and magnitude of the significant genetic parameters. No cline was adequately described by a simple additive-dominance model, and significant epistatic and maternal effects occurred in most, but not all, of the clines. Generation variances were also analyzed. Only one cline was described sufficiently by a simple additive variance model, indicating significant epistatic, maternal, or linkage effects in the remaining two clines. The diversity in genetic architecture of the clines suggests that natural selection has produced similar phenotypic divergence by different combinations of gene action and interaction.

Mobile Element 297 in the Abd-B gene of Drosophila melanogaster, Not Delta 88, Is Responsible for the tuh-3 Mutation

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 679-688
Author(s):  
Judith A Mack ◽  
Ronald D Smith ◽  
David T Kuhn
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effects ◽  
Molecular Analysis ◽  
Maternal Effect ◽  
Mobile Element ◽  
Bithorax Complex ◽  
Genital Tissue

The tumorous-head-3 (tuh-3) mutation has been associated with the insertion of mobile element Delta 88 at +200 on the bithorax complex (BX-C) DNA map, 5′ of all Abdominal-B (Abd-B) transcripts. Different phenotypes of tuh-3 are regulated by the tumorous-head-1 (tuh-1) maternal effect locus. In the presence of the recessive tuh-1h maternal effect, tuh-3 offspring produce homeotic abdominal and genital tissue in the head. In the presence of the dominant tuh-1g maternal effect, tuh-3 offspring have normal heads but now show genital defects. One other mutant, I127B, produces flies with identical defects to that of tuh-3 in the presence of both maternal effects. Molecular analysis of I127B revealed the insertion of mobile element 297 in the Abd-B gene, ∼25 kb downstream of the Delta 88 insertion in tuh-3. No other abnormalities were detected. Reexamination of our tuh-3 strain revealed a 297 insertion in an identical region to that of I127B, in addition to the Delta 88 insertion. Recombinants of tuh-3, carrying 297 only, produced homeotic head defects and genital defects in the presence of the tuh-1h and tuh-1R maternal effects, respectively. Recombinants of tuh-3, carrying Delta 88 only, failed to produce any defects in the presence of either maternal effect. Based upon these results, we propose that it is the 297 insertion in the Abd-B gene, not Delta 88, that is responsible for the tuh-3 mutation.

scholarly journals Environmental effects on body size variation in Drosophila melanogaster and its cellular basis

1997 ◽  
Vol 70 (1) ◽  
pp. 35-43 ◽  
Author(s):  
G. H. DE MOED ◽  
G. DE JONG ◽  
W. SCHARLOO
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Body Size ◽  
Cell Size ◽  
Wing Length ◽  
Size Variation ◽  
Cell Number ◽  
Food Level ◽  
Mean Size ◽  
Food Conditions

Eight isofemale lines of Drosophila melanogaster were raised at four temperatures and at four yeast concentrations in their food. Temperature and food show a significant interaction in determining wing length and thorax length, affecting mean size per line and genetic variation between lines. The combination of low temperature and poor food conditions leads to a sharp increase in the genetic variation over lines of both body size characters. The increase in genetic variation in wing length under less favourable conditions is due to an increase in genetic variation of both cell size and cell number. Changes in wing area in response to both temperature and food level follow a common cell size/cell number trajectory. Changes in wing size are obtained by line-specific changes in the cellular composition of the wing, rather than by changes specific for the environmental factor.

scholarly journals Trans-generational effect of protein restricted diet on adult body and wing size of Drosophila melanogaster

2020 ◽  
Author(s):  
Sudhakar Krittika ◽  
Pankaj Yadav
Keyword(s):  
Body Weight ◽  
Drosophila Melanogaster ◽  
Body Size ◽  
Wing Length ◽  
Wing Size ◽  
Restricted Diet ◽  
Trade Offs ◽  
Adult Body ◽  
Control Food ◽  
Protein Restricted Diet

AbstractDietary Restriction (DR) via protein restriction (PR) has become an inquisitive field and has established feasible trade-offs between various fitness and behavioral traits in Drosophila melanogaster to understand lifespan or aging in a nutritionally challenged environment. However, the phenotypes of body size, weight and wing length respond according to factors such as flies’ genotype, environmental exposure, and parental diet. Hence, understanding the long-term effect of PR on these phenotypes is essential. Here, we demonstrate the effect of PR diet on body size, weight and normal & dry wing length of flies subjected to PR50 and PR70 (50% and 70% protein content present in control food respectively) for 20 generations from pre-adult stage. We found that PR fed flies have lower body weight, relative water content (in males), unaltered (PR50%) and higher (PR70%) relative fat content in males, smaller normal and dry body size as compared to control and generations 1 and 2. Interestingly, wing size and pupal size of PR flies are smaller and showed significant effects of diet and generation. Thus, these traits are sex and generation dependent along with an interaction of diet, which is capable of modulating these results variably. Our study suggests that trans-generational effect is more prominent in influencing these traits and wing length might not be a predictor for body size. Taken together, the trans-generational effect of PR on fitness and fitness-related traits might be helpful to understand the underpinning mechanisms of evolution and aging in fruit flies D. melanogaster.Summary statementTwenty generations of protein restricted diet have a diet and generation dependent effect on adult body size, wing length and body weight.

scholarly journals A NOTE ON THE MATERNAL EFFECT MUTANTS DAUGHTERLESS AND ABNORMAL OOCYTE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 73 (1) ◽  
pp. 73-86
Author(s):  
Arthur P Mange ◽  
L Sandler
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effect ◽  
Sex Chromosome ◽  
Chromosome 2 ◽  
Dominant Marker ◽  
Enhancing Effect ◽  
X Irradiation ◽  
The Right ◽  
Chromosome Breakpoint ◽  
Special Region

ABSTRACT Two deficiencies for, and a dominant enhancer of, the second chromosome maternal effect mutant, "daughterless" (da), were induced with X-irradiation. Their properties were studied with respect to both da and the linked maternal effect mutant, "abnormal oocyte" (abo), with the following conclusions. (1) The most probable map positions of da and abo are: J–½–da–2½–abo, where J is a dominant marker located at 41 on the standard map. (2) The da locus is in bands 31CD-F on the polytene chromosome map; abo is to the right of 32A. (3) Because homozygous da individuals survive while individuals carrying da and a deficiency for da are lethal, it is concluded that da is hypomorphic. (4) From a weak da-like maternal effect in heterozygous da females induced by an "Enhancer of da," we have confirmed a previous report that (a) the amount of sex chromosome heterochromatin contributed by the father can influence the severity of the da maternal effect, and (b) the sex chromosome heterochromatin which influences the da effect is different from that which influences the abo effect. (5) The possibility that da and abo are in a special region of chromosome 2 concerned with the regulation of sex chromosome heterochromatin is strengthened by the observation that the Enhancer of da appears to rescue abnormal eggs produced by homozygous abo mothers. (6) The Enhancer of da is a translocation between chromosomes 2 and 3 with the second chromosome breakpoint in the basal heterochromatin; because the enhancing effect maps in this region of chromosome 2, it is possible that autosomal, as well as sex chromosomal, heterochromatin interacts with da and abo.

scholarly journals Insect body size changes under future warming projections: a case study of Chironomidae (Insecta: Diptera)

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Rungtip Wonglersak ◽  
Phillip B. Fenberg ◽  
Peter G. Langdon ◽  
Stephen J. Brooks ◽  
Benjamin W. Price
Keyword(s):  
Body Size ◽  
Ambient Temperature ◽  
Wing Length ◽  
The Body ◽  
Mesocosm Experiments ◽  
Future Warming ◽  
Increasing Temperature ◽  
Emergence Date ◽  
Average Body

AbstractChironomids are a useful group for investigating body size responses to warming due to their high local abundance and sensitivity to environmental change. We collected specimens of six species of chironomids every 2 weeks over a 2-year period (2017–2018) from mesocosm experiments using five ponds at ambient temperature and five ponds at 4°C higher than ambient temperature. We investigated (1) wing length responses to temperature within species and between sexes using a regression analysis, (2) interspecific body size responses to test whether the body size of species influences sensitivity to warming, and (3) the correlation between emergence date and wing length. We found a significantly shorter wing length with increasing temperature in both sexes of Procladius crassinervis and Tanytarsus nemorosus, in males of Polypedilum sordens, but no significant relationship in the other three species studied. The average body size of a species affects the magnitude of the temperature-size responses in both sexes, with larger species shrinking disproportionately more with increasing temperature. There was a significant decline in wing length with emergence date across most species studied (excluding Polypedilum nubeculosum and P. sordens), indicating that individuals emerging later in the season tend to be smaller.

scholarly journals Ontogeny of body size and shape of Antarctic and subantarctic fur seals

2007 ◽  
Vol 85 (12) ◽  
pp. 1275-1285 ◽  
Author(s):  
Sebastián P. Luque ◽  
Edward H. Miller ◽  
John P.Y. Arnould ◽  
Magaly Chambellant ◽  
Christophe Guinet
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Morphological Traits ◽  
Body Shape ◽  
Size And Shape ◽  
Fur Seals ◽  
Fur Seal ◽  
Adult Body ◽  
Weaning Age ◽  
Lactation Duration

Pre- and post-weaning functional demands on body size and shape of mammals are often in conflict, especially in species where weaning involves a change of habitat. Compared with long lactations, brief lactations are expected to be associated with fast rates of development and attainment of adult traits. We describe allometry and growth for several morphological traits in two closely related fur seal species with large differences in lactation duration at a sympatric site. Longitudinal data were collected from Antarctic ( Arctocephalus gazella (Peters, 1875); 120 d lactation) and subantarctic ( Arctocephalus tropicalis (Gray, 1872); 300 d lactation) fur seals. Body mass was similar in neonates of both species, but A. gazella neonates were longer, less voluminous, and had larger foreflippers. The species were similar in rate of preweaning growth in body mass, but growth rates of linear variables were faster for A. gazella pups. Consequently, neonatal differences in body shape increased over lactation, and A. gazella pups approached adult body shape faster than did A. tropicalis pups. Our results indicate that preweaning growth is associated with significant changes in body shape, involving the acquisition of a longer, more slender body with larger foreflippers in A. gazella. These differences suggest that A. gazella pups are physically more mature at approximately 100 d of age (close to weaning age) than A. tropicalis pups of the same age.

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