Genetic basis of offspring number-body weight tradeoff in Drosophila melanogaster

Abstract Drosophila melanogaster egg production, a proxy for fecundity, is an extensively studied life-history trait with a strong genetic basis. As eggs develop into larvae and adults, space and resource constraints can put pressure on the developing offspring, leading to a decrease in viability, body size, and lifespan. Our goal was to map the genetic basis of offspring number and weight under the restriction of a standard laboratory vial. We screened 143 lines from the Drosophila Genetic Reference Panel for offspring numbers and weights to create an ‘offspring index’ that captured the number vs. weight trade-off. We found 18 genes containing 30 variants associated with variation in the offspring index. Validation of hid, Sox21b, CG8312, and mub candidate genes using gene disruption mutants demonstrated a role in adult stage viability, while mutations in Ih and Rbp increased offspring number and increased weight, respectively. The polygenic basis of offspring number and weight, with many variants of small effect, as well as the involvement of genes with varied functional roles, support the notion of Fisher’s “infinitesimal model” for this life-history trait.

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Genetic basis of offspring number and body weight variation in Drosophila melanogaster

10.1101/2020.07.14.203406 ◽

2020 ◽

Author(s):

Jamilla Akhund-Zade ◽

Shraddha Lall ◽

Erika Gajda ◽

Denise Yoon ◽

Benjamin de Bivort

Keyword(s):

Drosophila Melanogaster ◽

Life History ◽

Egg Production ◽

Genetic Basis ◽

Resource Constraints ◽

Adult Stage ◽

Life History Trait ◽

Functional Roles ◽

Offspring Number ◽

Weight Variation

AbstractDrosophila melanogaster egg production, a proxy for fecundity, is an extensively studied life-history trait with a strong genetic basis. As eggs develop into larvae and adults, space and resource constraints can put pressure on the developing offspring, leading to a decrease in viability, body size, and lifespan. Our goal was to map the genetic basis of offspring number and weight under the restriction of a standard laboratory vial. We screened 143 lines from the Drosophila Genetic Reference Panel for offspring numbers and weights to create an ‘offspring index’ that captured the number vs. weight trade-off. We found 30 associated variants in 18 genes. Validation of hid, Sox21b, CG8312, and mub candidate genes using gene disruption mutants demonstrated a role in adult stage viability, while mutations in Ih and Rbp increased offspring number and increased weight, respectively. The polygenic basis of offspring number and weight, with many variants of small effect, as well as the involvement of genes with varied functional roles, support the notion of Fisher’s “infinitesimal model” for this life-history trait.

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Genetic Basis of Increased Lifespan and Postponed Senescence in Drosophila melanogaster

G3 Genes|Genome|Genetics ◽

10.1534/g3.120.401041 ◽

2020 ◽

Vol 10 (3) ◽

pp. 1087-1098

Author(s):

Grace A. Parker ◽

Nathan Kohn ◽

Ally Spirina ◽

Anna McMillen ◽

Wen Huang ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Genetic Basis ◽

Natural Populations ◽

Life History Trait ◽

Reproductive Senescence ◽

Evolutionary Forces ◽

Human Orthologs ◽

Evolutionarily Conserved ◽

Conserved Genes ◽

B Lines

Limited lifespan and senescence are near-universal phenomena. These quantitative traits exhibit variation in natural populations due to the segregation of many interacting loci and from environmental effects. Due to the complexity of the genetic control of lifespan and senescence, our understanding of the genetic basis of variation in these traits is incomplete. Here, we analyzed the pattern of genetic divergence between long-lived (O) Drosophila melanogaster lines selected for postponed reproductive senescence and unselected control (B) lines. We quantified the productivity of the O and B lines and found that reproductive senescence is maternally controlled. We therefore chose 57 candidate genes that are expressed in ovaries, 49 of which have human orthologs, and assessed the effects of RNA interference in ovaries and accessary glands on lifespan and reproduction. All but one candidate gene affected at least one life history trait in one sex or productivity week. In addition, 23 genes had antagonistic pleiotropic effects on lifespan and productivity. Identifying evolutionarily conserved genes affecting increased lifespan and delayed reproductive senescence is the first step toward understanding the evolutionary forces that maintain segregating variation at these loci in nature and may provide potential targets for therapeutic intervention to delay senescence while increasing lifespan.

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X- and Y-chromosome linked paternal effects on a life-history trait

Biology Letters ◽

10.1098/rsbl.2011.0608 ◽

2011 ◽

Vol 8 (1) ◽

pp. 71-73 ◽

Cited By ~ 14

Author(s):

Urban Friberg ◽

Andrew D. Stewart ◽

William R. Rice

Keyword(s):

Drosophila Melanogaster ◽

Life History ◽

Parental Care ◽

Maternal Effects ◽

Phenotypic Variation ◽

Genetic Material ◽

Life History Trait ◽

Paternal Effects ◽

Epigenetic Effects ◽

Males And Females

Males and females usually invest asymmetrically in offspring. In species lacking parental care, females influence offspring in many ways, while males only contribute genetic material via their sperm. For this reason, maternal effects have long been considered an important source of phenotypic variation, while paternal effects have been presumed to be absent or negligible. The recent surge of studies showing trans-generational epigenetic effects questions this assumption, and indicates that paternal effects may be far more important than previously appreciated. Here, we test for sex-linked paternal effects in Drosophila melanogaster on a life-history trait, and find substantial support for both X- and Y-linked effects.

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Genome-wide association mapping in a wild avian population identifies a link between genetic and phenotypic variation in a life-history trait

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.0156 ◽

2015 ◽

Vol 282 (1806) ◽

pp. 20150156 ◽

Cited By ~ 34

Author(s):

Arild Husby ◽

Takeshi Kawakami ◽

Lars Rönnegård ◽

Linnéa Smeds ◽

Hans Ellegren ◽

...

Keyword(s):

Life History ◽

Association Mapping ◽

Genetic Basis ◽

Snp Array ◽

Genome Wide Association ◽

Life History Trait ◽

Lifetime Reproductive Success ◽

Phenotypic Variance ◽

Sexual Antagonism ◽

Genome Wide

Understanding the genetic basis of traits involved in adaptation is a major challenge in evolutionary biology but remains poorly understood. Here, we use genome-wide association mapping using a custom 50 k single nucleotide polymorphism (SNP) array in a natural population of collared flycatchers to examine the genetic basis of clutch size, an important life-history trait in many animal species. We found evidence for an association on chromosome 18 where one SNP significant at the genome-wide level explained 3.9% of the phenotypic variance. We also detected two suggestive quantitative trait loci (QTLs) on chromosomes 9 and 26. Fitness differences among genotypes were generally weak and not significant, although there was some indication of a sex-by-genotype interaction for lifetime reproductive success at the suggestive QTL on chromosome 26. This implies that sexual antagonism may play a role in maintaining genetic variation at this QTL. Our findings provide candidate regions for a classic avian life-history trait that will be useful for future studies examining the molecular and cellular function of, as well as evolutionary mechanisms operating at, these loci.

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Genetic Basis and Selection for Life-History Trait Plasticity on Alternative Host Plants for the Cereal Aphid Sitobion avenae

PLoS ONE ◽

10.1371/journal.pone.0106179 ◽

2014 ◽

Vol 9 (9) ◽

pp. e106179 ◽

Cited By ~ 18

Author(s):

Xinjia Dai ◽

Suxia Gao ◽

Deguang Liu

Keyword(s):

Life History ◽

Host Plants ◽

Genetic Basis ◽

Sitobion Avenae ◽

Life History Trait ◽

Alternative Host ◽

Cereal Aphid ◽

Trait Plasticity ◽

Selection For

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Social and physical environment independently affect oviposition decisions in Drosophila melanogaster

10.1101/2021.01.27.428449 ◽

2021 ◽

Author(s):

Emily R. Churchill ◽

Calvin Dytham ◽

Jon R. Bridle ◽

Michael D.F. Thom

Keyword(s):

Drosophila Melanogaster ◽

Spatial Distribution ◽

Egg Production ◽

Larval Density ◽

Offspring Number ◽

Resource Distributions ◽

Distribution Of Resources ◽

Social And Physical Environment ◽

Developmental Conditions ◽

Plastic Responses

AbstractIn response to environmental stimuli, including variation in the presence of conspecifics, animals show highly plastic responses in behavioural and physiological traits influencing reproduction. These responses have been extensively documented in males, but equivalent study of females is so far lacking. We expect females to be highly responsive to environmental variation, with significant impacts on fitness given females’ direct impact on offspring number, size, and developmental conditions. Using Drosophila melanogaster as a model, we manipulate (a) exposure to conspecific females, expected to influence their expectation of number of potential mates and larval density for their own offspring, and (b) test how prior consexual population density interacts with the spatial distribution of potential oviposition sites, with females expected to prefer clustered food resources that can support a larger number of eggs and larvae. After exposure to competition, females were slower to start copulating and reduced their copulation duration – the opposite effect to that observed in males previously exposed to rivals. There was a parallel and perhaps related effect on egg production, with females previously housed in groups laying fewer eggs than those that were housed in solitude. The spatial distribution of resources also influenced oviposition behaviour: females clearly preferred aggregated patches of substrate, being more likely to lay, and laying on more of the available patches, in the clustered environment. However, we found no significant interaction between prior housing conditions and resource patchiness, indicating that females did not perceive the value of different resource distributions differently when they were expecting either high or low levels of larval competition. While exposure to consexual competition influences copulatory behaviours, it is the distribution of oviposition resources that has a greater impact on oviposition decisions.

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Heterogeneous genetic basis of age at maturity in salmonid fishes

10.1101/2020.07.24.220111 ◽

2020 ◽

Cited By ~ 1

Author(s):

Charles D. Waters ◽

Anthony Clemento ◽

Tutku Aykanat ◽

John Carlos Garza ◽

Kerry A. Naish ◽

...

Keyword(s):

Life History ◽

Atlantic Salmon ◽

Sockeye Salmon ◽

Genetic Basis ◽

Coho Salmon ◽

Strong Association ◽

Life History Trait ◽

Age At Maturity ◽

A Genome ◽

Conservation And Management

AbstractUnderstanding the genetic basis of repeated evolution of the same phenotype across taxa is a fundamental aim in evolutionary biology and has applications to conservation and management. However, the extent to which interspecific life-history trait polymorphisms share evolutionary pathways remains under-explored. We address this gap by studying the genetic basis of a key life-history trait, age at maturity, in four species of Pacific salmon (genus Oncorhynchus) that exhibit intra- and interspecific variation in this trait – Chinook Salmon, Coho Salmon, Sockeye Salmon, and Steelhead Trout. We tested for associations in all four species between age at maturity and two genome regions, six6 and vgll3, that are strongly associated with the same trait in Atlantic Salmon (Salmo salar). We also conducted a genome-wide association analysis in Steelhead to assess whether additional regions were associated with this trait. We found the genetic basis of age at maturity to be heterogeneous across salmonid species. Significant associations between six6 and age at maturity were observed in two of the four species, Sockeye and Steelhead, with the association in Steelhead being particularly strong in both sexes (p = 4.46×10−9 after adjusting for genomic inflation). However, no significant associations were detected between age at maturity and the vgll3 genome region in any of the species, despite its strong association with the same trait in Atlantic Salmon. We discuss possible explanations for the heterogeneous nature of the genetic architecture of this key life-history trait, as well as the implications of our findings for conservation and management.

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