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

2010 ◽  
Vol 92 (4) ◽  
pp. 253-259 ◽  
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.

scholarly journals The evolutionary potential of diet-dependent effects on lifespan and fecundity in a multi-parental population of Drosophila melanogaster

2018 ◽  
Author(s):  
Enoch Ng’oma ◽  
Wilton Fidelis ◽  
Kevin M. Middleton ◽  
Elizabeth G. King
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Genetic Correlations ◽  
Natural Populations ◽  
Evolutionary Potential ◽  
Fitness Components ◽  
Nutrient Imbalance ◽  
Quantitative Genetic ◽  
Nutritional Conditions ◽  
Quantitative Genetic Parameters

AbstractThe nutritional conditions experienced by a population play a major role in shaping trait evolution in many taxa. Constraints exerted by nutrient limitation or nutrient imbalance can influence the maximal value that fitness components such as reproduction and lifespan attains, and organisms may shift how resources are allocated to different structures and functions in response to changes in nutrition. Whether the phenotypic changes associated with changes in nutrition represent an adaptive response is largely unknown. Further, it is unclear whether the response of fitness components to diet even has the potential to evolve in most systems. In this study, we use an admixed multiparental population of Drosophila melanogaster reared in three different diet conditions to estimate quantitative genetic parameters for lifespan and fecundity. We find significant genetic variation for both traits in our population and show that lifespan has moderate to high heritabilities within diets. Genetic correlations for lifespan between diets were significantly less than one, demonstrating a strong genotype by diet interaction. These findings demonstrate substantial standing genetic variation in our population that is comparable to natural populations and highlights the potential for adaptation to changing nutritional environments.

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

Genetics ◽  
1988 ◽  
Vol 119 (2) ◽  
pp. 421-433
Author(s):  
D E Cowley ◽  
W R Atchley
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
X Chromosome ◽  
Dosage Compensation ◽  
Imaginal Disc ◽  
Genetic Correlations ◽  
Body Parts ◽  
Quantitative Genetic ◽  
Males And Females

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.

scholarly journals A quantitative genetic analysis of fitness and its components in Drosophila melanogaster

1986 ◽  
Vol 47 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Trudy F. C. Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Strongly Correlated ◽  
Wild Type ◽  
Relative Contribution ◽  
Quantitative Characters ◽  
Quantitative Genetic ◽  
Bristle Number ◽  
Metric Traits ◽  
Average Fitness

SummaryForty-one third chromosomes extracted from a natural population of Drosophila melanogaster were assessed for net fitness and for the quantitative characters viability, net fertility, female productivity, male weight, abdominal bristle number, and sternopleural bristle number. Net homozygous and heterozygous fitness of the third chromosomes was estimated by competition against a marked balancer third chromosome. Average fitness of the homozygous lines relative to wild-type heterozygotes was 0·13, indicating substantial inbreeding depression for net fitness. All significant correlations of quantitative characters with fitness and with each other were high and positive. Homozygous fitness is strongly correlated with net fertility, viability, and female productivity, moderately associated with male weight, and not significantly associated with bristle traits. The combination of metric traits which best predicts homozygous fitness is the simple multiple of viability and female productivity. Heterozygous fitness is not correlated with homozygous fitness; furthermore, the relative contribution of metric traits to fitness in a heterozygous population is likely to be different from that deduced from homozygous lines. These observations are consistent with a model of genetic variation for fitness in natural populations caused by segregation of rare deleterious recessive alleles.

scholarly journals Genetic variation affecting heart rate in Drosophila melanogaster

1999 ◽  
Vol 74 (2) ◽  
pp. 121-128 ◽  
Author(s):  
J. ROBBINS ◽  
R. AGGARWAL ◽  
R. NICHOLS ◽  
G. GIBSON
Keyword(s):  
Heart Rate ◽  
Drosophila Melanogaster ◽  
Heart Function ◽  
Susceptibility Gene ◽  
Natural Populations ◽  
Model Organism ◽  
Genetic Dissection ◽  
Wild Type ◽  
Quantitative Genetic ◽  
Wide Range

Heart rate in pre-pupae of Drosophila melanogaster is shown to vary over a wide range from 2·5 to 3·7 beats per second. Quantitative genetic analysis of a sample of 11 highly inbred lines indicates that approaching one-quarter of the total variance in natural populations can be attributed to genetic differences between flies. A hypomorphic allele of the potassium channel gene ether-a-gogo, which is homologous to a human long-QT syndrome susceptibility gene (HERG), has a heart rate at the low end of the wild-type range, but this effect can be suppressed in certain wild-type genetic backgrounds. This study provides a baseline for investigation of pharmacological and other physiological influences on heart rate in the model organism, and implies that quantitative genetic dissection will provide insight into the molecular basis for variation in normal and arrhythmic heart function.

scholarly journals Quantitative genetic variation of enzyme activities in natural populations of Drosophila melanogaster

1980 ◽  
Vol 77 (2) ◽  
pp. 1073-1077 ◽  
Author(s):  
C. C. Laurie-Ahlberg ◽  
G. Maroni ◽  
G. C. Bewley ◽  
J. C. Lucchesi ◽  
B. S. Weir
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Enzyme Activities ◽  
Natural Populations ◽  
Quantitative Genetic

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

Genetics ◽  
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.

The effect of mating on starvation resistance in natural populations of Drosophila melanogaster

2011 ◽  
Vol 26 (4) ◽  
pp. 813-823 ◽  
Author(s):  
Julieta Goenaga ◽  
Julián Mensch ◽  
Juan José Fanara ◽  
Esteban Hasson
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Starvation Resistance

scholarly journals Quantitative genetics of postponed aging in Drosophila melanogaster. II. Analysis of selected lines.

Genetics ◽  
1991 ◽  
Vol 127 (4) ◽  
pp. 729-737
Author(s):  
E W Hutchinson ◽  
A J Shaw ◽  
M R Rose
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effects ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Starvation Resistance ◽  
Selected Lines ◽  
Quantitative Genetic ◽  
Degree Of Differentiation ◽  
Postponed Aging ◽  
Allelic Differentiation

Abstract Quantitative genetic analyses of Drosophila melanogaster stocks with postponed aging have suffered from the problem of a lack of certainty concerning patterns of allelic differentiation. The present experiments were designed to alleviate this difficulty by selecting for enhanced levels of characters known to be related to postponed aging. Selection successfully increased the degree of differentiation of postponed aging stocks with respect to starvation resistance and fecundity, but persistent additive genetic variance suggested that selection did not result in fixation of alleles. The artificially selected stocks were subjected to crosses to test for patterns of dominance and maternal effects. There was little evidence for these effects in the inheritance of the characters underlying postponed aging, even with the increased differentiation of the selected stocks.

scholarly journals Genetic variation in phenology and growth among and within Norway spruce populations from two altitudinal transects in Mid-Norway

Silva Fennica ◽  
2019 ◽  
Vol 53 (1) ◽  
Author(s):  
Tore Skrøppa ◽  
Arne Steffenrem
Keyword(s):  
High Altitude ◽  
Norway Spruce ◽  
Genetic Correlations ◽  
Natural Populations ◽  
Height Growth ◽  
Population Variation ◽  
Clinal Variation ◽  
Short Term ◽  
Narrow Sense Heritability

Progenies from open pollinated cones collected in natural populations of Norway spruce ( (L. Karst.)) distributed along two altitudinal transects in Mid-Norway were tested in the nursery, in short term tests and in long-term field trials. The populations showed clinal variation related to the mean annual temperatures of the populations, with the earliest bud flush and cessation of shoot elongation and lowest height at age nine years for the high altitude populations. Within population variation was considerable as the narrow sense heritability for these traits was 0.67, 0.31 and 0.09 in one transect and 0.55, 0.18 and 0.14 in the other transect, respectively. Lammas shoots occurred in the short term trials with large variation in frequency between years. There was significant family variation for this trait, but also interactions between populations and year. The variance within populations was considerably larger in the populations from low altitude compared to the high-altitude populations. Significant genetic correlations between height and phenology traits and damage scores indicate that families flushing early and ceasing growth late were taller. Taller families also had higher frequencies of damages. Selection of the top 20% families for height growth in short term tests at age nine years gave a simulated gain of 11% increased height growth at age 18 years in long term trials at altitudes similar to those of origin of the populations. The gain was negative when high altitude populations were selected based on testing in the lowland.Picea abies

Variation in cedar leaf blight (Didymascella thujina) resistance of western redcedar (Thuja plicata)

2007 ◽  
Vol 37 (10) ◽  
pp. 1978-1986 ◽  
Author(s):  
John H. Russell ◽  
Harry H. Kope ◽  
Peter Ades ◽  
Heidi Collinson
Keyword(s):  
British Columbia ◽  
Genetic Correlations ◽  
Natural Populations ◽  
High Elevation ◽  
Leaf Blight ◽  
Population Variation ◽  
Thuja Plicata ◽  
Western Redcedar ◽  
Queen Charlotte Islands ◽  
River Site

Western redcedar ( Thuja plicata Donn ex D. Don) seedlings from a population study with family structure were planted at four sites across coastal British Columbia. All seedlings at the time of planting were infected with cedar leaf blight (CLB) ( Didymascella thujina (E.J. Durand) Maire). CLB severity and tree heights were measured at various ages from 2 to 12 years. There were significant site differences in CLB severity with the coastal hypermaritime site showing the most and with the submaritime site showing the least. Population differences in disease severity were evident with British Columbia coastal, low-elevation populations exhibiting the most resistance and with British Columbia high-elevation and California sources showing the least. Population resistance was consistent across all four sites (all r > 0.90, p < 0.001). Coefficients of additive genetic variation in CLB severity at all four sites varied from 13.2% to 20.1% with narrow-sense heritabilities from 0.21 to 0.66. Type B genetic correlations in CLB severity across sites averaged 0.59. Type A genetic correlations between 6 year CLB severity and height at the Jordan River site on western Vanvouver Island and at the site on the Queen Charlotte Islands were –0.96 and –0.86 (p < 0.001), respectively. Results are discussed with respect to climatic influences and prior exposure to CLB on among- and within-population variation in western redcedar natural populations and impact on gene resource management.

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