Whole-body transcriptomics of Nasonia vitripennis females as they respond to sex allocation cues
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ABSTRACT:
ORGANISM(S): Nasonia vitripennis
PROVIDER: GSE74241 | GEO | 2015/11/11
SECONDARY ACCESSION(S): PRJNA299590
REPOSITORIES: GEO
Similar Datasets
Project description:Linking the evolution of the phenotype to the underlying genotype is a key aim of evolutionary genetics and is crucial to our understanding of how natural selection shapes a trait. Here we consider the genetic basis of sex allocation behaviour in the parasitoid wasp Nasonia vitripennis using a transcriptomics approach. Females allocate offspring sex in line with Local Mate Competition (LMC) theory. Female-biased sex ratios are produced when one or few females lay eggs on a patch. As the number of females contributing offspring to a patch increases, less female-biased sex ratios are favoured. We contrasted the transcriptomic responses of females as they oviposit under conditions known to influence sex allocation: foundress number (a social cue) and the state of the host (parasitised or not). We found, that when females encounter other females on a patch, or assess host quality with their ovipositors, the resulting changes in sex allocation is not associated with significant changes in whole-body gene expression. We also found that the gene expression changes produced by females, as they facultatively allocate sex in response to a host cue and a social cue, are very closely correlated. We expanded the list of candidate genes associated with oviposition behaviour in Nasonia, some of which may be involved in fundamental processes underlying the ability to facultatively allocate sex, including sperm storage and utilisation. 2 x 3 factorial design. Females were placed into 1 of 2 "foundress number" groups: 1) alone or 2) in the presence of 9 other females (co-foundresses). Females were further subdivided into host treatment groups: i) given no host, ii) given a fresh host and iii) given a pre-parasitised host. This gives a total of 6 possible treatment combinations. For each of these 6 groups, 7 pools of 10 females were sequenced giving 42 libraries altogether.
2015-11-11 | E-GEOD-74241 | biostudies-arrayexpress
Project description:Female Nasonia facultatively vary their offspring sex ratio in line with Hamilton’s theory of Local Mate Competition (LMC). A single female or “foundress” laying eggs on a patch will lay just enough sons to fertilise her daughters. As the number of “foundresses” laying eggs on a patch increases (and LMC declines) females produce increasingly male-biased sex ratios. Phenotypic studies have revealed the cues females use to estimate the level of LMC their sons will experience but our understanding of the genetics underlying sex allocation is limited. Here, we exposed females to three foundress number conditions, i.e. three LMC conditions, and allowed them to oviposit. mRNA was extracted from only the heads of these females to target the brain tissue. The subsequent RNA-seq experiment confirmed that differential gene expression is not associated with the response to sex allocation cues and that we must instead turn to the underlying neuroscience to reveal the underpinnings of this impressive behavioural plasticity.
2018-01-11 | GSE105796 | GEO
Project description:For many behaviours studied at the phenotypic level, we have little or no idea of where to start searching for “candidate” genes: the transcriptome provides such a starting point. Here we consider transcriptomic changes associated with oviposition in the parasitoid wasp Nasonia vitripennis. Oviposition is a key behaviour, as females are faced with a variety of decisions that will impact offspring fitness. These include choosing between hosts of differing quality, as well as deciding on clutch size and offspring sex ratio. We compared the whole-body transcriptomes of resting or ovipositing female Nasonia using a “DEEP-Sage” gene expression approach on the Illumina sequencing platform.
2013-07-22 | GSE43352 | GEO
Project description:Whole-body transcriptomics of Nasonia vitripennis females as they respond to sex allocation cues
| PRJNA299590 | ENA
Project description:The extraordinary range in the degree of sexual dimorphism (SD) among animal species is widely perceived to be caused in part by differences in patterns of sexual selection, but sex-specific adaptations and sex chromosome differences also play a role. Studies in insects have discovered a substantial number of sex-biased genes, but little is known about the epigenetic basis of SD. The degree and genome-wide distribution of sex-biased expression become interesting questions in hymenoptera species with haplodiploid sex-determination. To study the genetic and epigenetic architecture of SD and understand the conservation and evolution of sex-biased expression in a haplodiploid system that lacks sex chromosomes, we performed RNA-seq and whole-genome bisulfite sequencing in female and male adult samples of two parasitoid wasp species, Nasonia vitripennis and Nasonia giraulti. More than 75% of the expressed genes displayed significantly sex-biased expression. Both the number and the degree of sex-biased genes are higher than insects like Drosophila melanogaster, which have sex-chromosome mediated sex determination. Females from the two Nasonia species have far more similar expression profiles than does the contrast between the two sexes within either species. Interestingly, the extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes are highly enriched for key enzymes in sex-pheromone synthesis; female-biased genes are enriched for nuclear-located genes that are responsible for epigenetic regulation of gene expression. Unlike gene expression profiles, DNA methylomes are more similar within species, and no stable differentially methylated genes have been found between the two sexes, suggesting that DNA methylation is not directly responsible for the molecular basis of SD. However, methylation status does influence sex-biased expression: 80% of female-biased genes are methylated, which is more than two-fold higher than the genome average (30%); almost all male-biased and sex-specific genes are non-methylated, which is consistent with the fact that methylated genes have house-keeping functions and a broader expression breadth. Evolutionarily, male-biased genes have greater sequence divergence between the two species, and they are more likely to have a functional paralog in the Nasonia genome. Sex-specific genes have significantly higher non-synonymous substitution rates and dN/dS ratios. In addition, local clusters of sex-biased genes in the genome may have epigenetic properties similar to the sex chromosome. In summary, Nasonia accomplish a striking degree of sex-differential expression through a difference in ploidy along with associated differences in methylations status. Whole-genome bisulfite sequencing of 24-hour adult whole body samples of Nasonia vitripennis and Nasonia giraulti using Iilumina sequencing.
2015-06-08 | E-GEOD-61158 | biostudies-arrayexpress
Project description:The extraordinary range in the degree of sexual dimorphism (SD) among animal species is widely perceived to be caused in part by differences in patterns of sexual selection, but sex-specific adaptations and sex chromosome differences also play a role. Studies in insects have discovered a substantial number of sex-biased genes, but little is known about the epigenetic basis of SD. The degree and genome-wide distribution of sex-biased expression become interesting questions in hymenoptera species with haplodiploid sex-determination. To study the genetic and epigenetic architecture of SD and understand the conservation and evolution of sex-biased expression in a haplodiploid system that lacks sex chromosomes, we performed RNA-seq and whole-genome bisulfite sequencing in female and male adult samples of two parasitoid wasp species, Nasonia vitripennis and Nasonia giraulti. More than 75% of the expressed genes displayed significantly sex-biased expression. Both the number and the degree of sex-biased genes are higher than insects like Drosophila melanogaster, which have sex-chromosome mediated sex determination. Females from the two Nasonia species have far more similar expression profiles than does the contrast between the two sexes within either species. Interestingly, the extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes are highly enriched for key enzymes in sex-pheromone synthesis; female-biased genes are enriched for nuclear-located genes that are responsible for epigenetic regulation of gene expression. Unlike gene expression profiles, DNA methylomes are more similar within species, and no stable differentially methylated genes have been found between the two sexes, suggesting that DNA methylation is not directly responsible for the molecular basis of SD. However, methylation status does influence sex-biased expression: 80% of female-biased genes are methylated, which is more than two-fold higher than the genome average (30%); almost all male-biased and sex-specific genes are non-methylated, which is consistent with the fact that methylated genes have house-keeping functions and a broader expression breadth. Evolutionarily, male-biased genes have greater sequence divergence between the two species, and they are more likely to have a functional paralog in the Nasonia genome. Sex-specific genes have significantly higher non-synonymous substitution rates and dN/dS ratios. In addition, local clusters of sex-biased genes in the genome may have epigenetic properties similar to the sex chromosome. In summary, Nasonia accomplish a striking degree of sex-differential expression through a difference in ploidy along with associated differences in methylations status. Profiling of expression levels in Nasonia vitripennis and Nasonia giraulti adult male and female samples using Illumina RNA-seq
2015-06-08 | E-GEOD-61156 | biostudies-arrayexpress
Project description:For many behaviours studied at the phenotypic level, we have little or no idea of where to start searching for “candidate” genes: the transcriptome provides such a starting point. Here we consider transcriptomic changes associated with oviposition in the parasitoid wasp Nasonia vitripennis. Oviposition is a key behaviour, as females are faced with a variety of decisions that will impact offspring fitness. These include choosing between hosts of differing quality, as well as deciding on clutch size and offspring sex ratio. We compared the whole-body transcriptomes of resting or ovipositing female Nasonia using a “DEEP-Sage” gene expression approach on the Illumina sequencing platform. Single 2-day old mated Nasonia vitripennis females (ASymC strain) were isolated in a glass vial and provided with a single host to produce F1 daughters. Eight 2-day old mated F1 females were subsequently provided with three hosts to produce the F2 test females. We randomly selected one host from each F1 female, and isolated 16 2-day old mated F2 test females in glass tubes, of which eight were randomly allocated to the oviposition treatment and eight to the resting treatment. We provided the test females with a single host for 24 hours as pre-treatment to facilitate egg development. We then discarded the pre-treatment hosts and gave each female a piece of chromatography paper soaked in honey solution for a further 24 hours. For the experiment, we transferred the females to 1.5 mL Eppendorf tubes that contained a single host for the oviposition experiment, or were empty for the resting treatment. After 60 mins, females were flash-frozen in liquid nitrogen and stored on dry-ice until the addition of RNAlater-ICE (Ambion, Austin, TX, USA) after which they were transferred to -20C. All females in the oviposition treatment were observed to have commenced ovipositing. We pooled the F2 test females from each F1 mother according to treatment, generating a total of eight pooled samples per treatment (consisting of 8 females per pool) for RNA isolation and sequencing.
2013-07-22 | E-GEOD-43352 | biostudies-arrayexpress
Project description:The extraordinary range in the degree of sexual dimorphism (SD) among animal species is widely perceived to be caused in part by differences in patterns of sexual selection, but sex-specific adaptations and sex chromosome differences also play a role. Studies in insects have discovered a substantial number of sex-biased genes, but little is known about the epigenetic basis of SD. The degree and genome-wide distribution of sex-biased expression become interesting questions in hymenoptera species with haplodiploid sex-determination. To study the genetic and epigenetic architecture of SD and understand the conservation and evolution of sex-biased expression in a haplodiploid system that lacks sex chromosomes, we performed RNA-seq and whole-genome bisulfite sequencing in female and male adult samples of two parasitoid wasp species, Nasonia vitripennis and Nasonia giraulti. More than 75% of the expressed genes displayed significantly sex-biased expression. Both the number and the degree of sex-biased genes are higher than insects like Drosophila melanogaster, which have sex-chromosome mediated sex determination. Females from the two Nasonia species have far more similar expression profiles than does the contrast between the two sexes within either species. Interestingly, the extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes are highly enriched for key enzymes in sex-pheromone synthesis; female-biased genes are enriched for nuclear-located genes that are responsible for epigenetic regulation of gene expression. Unlike gene expression profiles, DNA methylomes are more similar within species, and no stable differentially methylated genes have been found between the two sexes, suggesting that DNA methylation is not directly responsible for the molecular basis of SD. However, methylation status does influence sex-biased expression: 80% of female-biased genes are methylated, which is more than two-fold higher than the genome average (30%); almost all male-biased and sex-specific genes are non-methylated, which is consistent with the fact that methylated genes have house-keeping functions and a broader expression breadth. Evolutionarily, male-biased genes have greater sequence divergence between the two species, and they are more likely to have a functional paralog in the Nasonia genome. Sex-specific genes have significantly higher non-synonymous substitution rates and dN/dS ratios. In addition, local clusters of sex-biased genes in the genome may have epigenetic properties similar to the sex chromosome. In summary, Nasonia accomplish a striking degree of sex-differential expression through a difference in ploidy along with associated differences in methylations status.
2015-06-08 | GSE61156 | GEO
Project description:The extraordinary range in the degree of sexual dimorphism (SD) among animal species is widely perceived to be caused in part by differences in patterns of sexual selection, but sex-specific adaptations and sex chromosome differences also play a role. Studies in insects have discovered a substantial number of sex-biased genes, but little is known about the epigenetic basis of SD. The degree and genome-wide distribution of sex-biased expression become interesting questions in hymenoptera species with haplodiploid sex-determination. To study the genetic and epigenetic architecture of SD and understand the conservation and evolution of sex-biased expression in a haplodiploid system that lacks sex chromosomes, we performed RNA-seq and whole-genome bisulfite sequencing in female and male adult samples of two parasitoid wasp species, Nasonia vitripennis and Nasonia giraulti. More than 75% of the expressed genes displayed significantly sex-biased expression. Both the number and the degree of sex-biased genes are higher than insects like Drosophila melanogaster, which have sex-chromosome mediated sex determination. Females from the two Nasonia species have far more similar expression profiles than does the contrast between the two sexes within either species. Interestingly, the extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes are highly enriched for key enzymes in sex-pheromone synthesis; female-biased genes are enriched for nuclear-located genes that are responsible for epigenetic regulation of gene expression. Unlike gene expression profiles, DNA methylomes are more similar within species, and no stable differentially methylated genes have been found between the two sexes, suggesting that DNA methylation is not directly responsible for the molecular basis of SD. However, methylation status does influence sex-biased expression: 80% of female-biased genes are methylated, which is more than two-fold higher than the genome average (30%); almost all male-biased and sex-specific genes are non-methylated, which is consistent with the fact that methylated genes have house-keeping functions and a broader expression breadth. Evolutionarily, male-biased genes have greater sequence divergence between the two species, and they are more likely to have a functional paralog in the Nasonia genome. Sex-specific genes have significantly higher non-synonymous substitution rates and dN/dS ratios. In addition, local clusters of sex-biased genes in the genome may have epigenetic properties similar to the sex chromosome. In summary, Nasonia accomplish a striking degree of sex-differential expression through a difference in ploidy along with associated differences in methylations status.
2015-06-08 | GSE61158 | GEO
Project description:A selection experiment has been set that selects females Mercurialis annua for increased allocation in male functions by depriving selected populations of all males. This resulted in a drastic phenotypic shift in sex allocation in females of the selected lines. The present RNA sequencing of control and selected lines after four generations of selection permits us to track the expression levels of previously identified male- and female-biased genes in females of the selected lines.
2018-08-01 | E-MTAB-6905 | biostudies-arrayexpress