Gene expression during head development in a sexually monomorphic stalk-eyed fly
Ontology highlight
ABSTRACT:
ORGANISM(S): Teleopsis quinqueguttata
SUBMITTER: Gerald Wilkinson
PROVIDER: E-GEOD-46694 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Stalk-eyed flies (family Diopsidae) are a model system for studying sexual selection due to the elongated and sexually dimorphic eye-stalks found in some species. These flies are of additional interest because their X chromosome is derived largely from an autosomal arm in other flies. To investigate how sex-biased expression arose on the novel X we compared gene expression between males and females using oligonucleotide microarrays and RNA from developing eyestalk tissue in the sexually monomorphic diopsid, Teleopsis quinqueguttata. We use probe sequence divergence to evaluate cross-species ascertainment bias and chromosome assignment to determine if sex linkage influence expression. Microarray analysis revealed sex-biased expression for only 1.9% of 3,748 genes expressed in eye-antennal imaginal discs. Analysis of probe sequences between species indicates that the lack of sex-biased expression is not due to ascertainment bias. These findings indicate that the the majority of sex-biased gene expression observed in developing heads of the dimorphic species, T. dalmanni, is causally related to development of dimorphic head shape.
2014-01-01 | GSE46694 | GEO
Project description:Background: Stalk-eyed flies (family Diopsidae) are a model system for studying sexual selection due to the presence of elongated and sexually dimorphic eye-stalks in many species. Recent genomic studies on these flies have revealed a neo-X chromosome and evidence of gene movement onto or off of this X chromosome. To determine if sex linkage and gene movement are related to sexual dimorphism and sexual conflict, we compared gene expression between males and females using oligonucleotide microarrays and RNA from either developing eyestalk tissue or adult heads from a dimorphic species, Teleopsis dalmanni, or from developing eyestalk tissue in a congeneric monomorphic species, T. quinqueguttata. Results: Comparison of gene expression between the sexes for 3,748 genes indicates that dosage compensation is present due to elevated expression of X-linked genes in males. However, sex-biased expression was detected in 26% of the genes present in eye-antennal imaginal discs of larval T. dalmanni. Functional annotation reveals that female-biased genes are associated with transcription, anatomical development and cell communication in the nucleus, while male-biased genes are associated with metabolism and the mitochondria. Comparison of gene expression between experiments identified 140 genes with concordant sex-biased expression in the larval and adult tissues of T. dalmanni and 17 genes with identical sex-biased expression between species. There were only five reversals of sex-biased expression across experiments. In T. dalmanni, male-biased genes are more common on autosomes than on the X while female-biased genes are more common on the X in T. quinqueguttata. Female-biased expression is especially common among genes that moved onto the ancestral X while male-biased expression is more common among genes that moved onto an autosome. Conclusions: Genes with sex-biased expression exhibit different functions in each sex as expected if sexual conflict has influenced their evolution. The strong relationship between sex-biased expression and gene movement found in this study is consistent with resolution of sexual conflict by an RNA- or DNA-mediated process that moves genes between chromosomes. Measurement of gene expression in additional species should provide a more complete picture of how gene expression change occurs over evolutionary time in these extraordinary flies. Two-condition experiment, female vs. male RNA using larval eye discs for two species (Teleopsis dalmanni, Teleopsis quinqueguttata), and adult heads for one species (Teleopsis dalmanni).
2012-04-09 | E-GEOD-37121 | biostudies-arrayexpress
Project description:Stalk-eyed flies (family Diopsidae) are a model system for studying sexual selection due to the elongated and sexually dimorphic eye-stalks found in many species. These flies are of additional interest because their X chromosome is derived largely from an autosomal arm in other flies. To identify candidate genes required for development of dimorphic eyestalks and investigate how sex-biased expression arose on the novel X we compared gene expression between males and females using oligonucleotide microarrays and RNA from developing eyestalk tissue or adult heads in the dimorphic diopsid, Teleopsis dalmanni. Microarray analysis revealed sex-biased expression for 26% of 3,748 genes expressed in eye-antennal imaginal discs and concordant sex-biased expression for 86 genes in adult heads. Overall, 415 female-biased and 482 male-biased genes were associated with dimorphic eyestalk development but not differential expression in the adult head. Functional analysis revealed that male-biased genes are disproportionately associated with growth and mitochondrial function while female-biased genes are associated with cell differentiation and patterning or are novel transcripts. With regard to chromosomal effects, dosage compensation occurs by elevated expression of X-linked genes in males. Genes with female-biased expression were more common on the X and less common on autosomes than expected, while male-biased genes exhibited no chromosomal pattern. Rates of protein evolution were lower for female-biased genes but higher for genes that moved on or off the novel X chromosome. These findings cannot be due to meiotic sex chromosome inactivation or by constraints associated with dosage compensation. Instead, they could be consistent with sexual conflict in which female-biased genes on the novel X act primarily to reduce eyespan in females while other genes increase eyespan in both sexes. Additional information on sex-biased gene expression in other tissues and related sexually monomorphic species could confirm this interpretation.
2012-04-10 | GSE37121 | GEO
Project description:Data from whole-body, head, thorax, abdomen, ovaries, testes and accessory glands was used to assess possible causes of a non-random distribution of sex-biased genes (sexually dimorphic expression). All samples were derived from virgin adult flies.
2013-11-05 | GSE45801 | GEO
Project description:Eye-stalks of some flies exhibit extreme sexual dimorphism, but little is known about the genetic mechanisms producing variation in these ornamental traits. Therefore, we constructed an EST database of genes expressed in the developing eye-antennal imaginal disc of the highly dimorphic species, Teleopsis dalmanni, and used this set of genes to construct high density oligoarrays and compare patterns of gene expression between lines of flies selected for divergent eyespan. Microarray experiments using eye-antennal disc tissue identified over 350 genes with significant differential expression between male flies from lines selected for high and low relative eyespan but did not reveal any primary biological process or pathway that is driving the expression differences. Custom 4x44K Agilent arrays were designed for approximately 3600 unique genes. Each gene was represented by three 60 bp oligo probes and each probe was printed in triplicate on each array. Each oligoarray was hybridized with two biological samples labeled either with cy3 or cy5. Each sample came from 25 sets of eye-antennal imaginal discs that were dissected from gut-purged male larvae. Samples were from lines of flies that had been under directional selection on males to either increase or decrease relative eyespan for 65 generations. Dye labeling was switched between lines for every other array. Ratios of median intensities were averaged across probes for each gene and then analyzed by SAM to identify genes with differential expression between lines.
2010-06-24 | E-GEOD-15444 | biostudies-arrayexpress
Project description:Background: Changes in gene regulation are thought to be crucial for the adaptation of organisms to their environment. Transcriptome analyses can be used to identify candidate genes for ecological adaptation, but can be complicated by variation in gene expression between tissues, sexes, or individuals. Here we use high-throughput RNA sequencing of a single Drosophila melanogaster tissue to detect brain-specific differences in gene expression between the sexes and between two populations, one from the ancestral species range in sub-Saharan Africa and one from the recently colonized species range in Europe. Results: Relatively few genes (<100) displayed sexually dimorphic expression in the brain, but there was an enrichment of sex-biased genes, especially male-biased genes, on the X chromosome. Over 340 genes differed in brain expression between flies from the African and European populations, with the between-population divergence being highly correlated between males and females. The differentially expressed genes include those involved in stress response, olfaction, and detoxification. Expression differences were associated with transposable element insertions at two genes implicated in insecticide resistance (Cyp6g1 and CHKov1). Conclusions: Analysis of the brain transcriptome revealed many genes differing in expression between populations that were not detected in previous studies using whole flies. There was little evidence for sex-specific regulatory adaptation in the brain, as most expression differences between populations were observed in both males and females. The enrichment of genes with sexually dimorphic expression on the X chromosome is consistent with dosage compensation mechanisms affecting sex-biased expression in somatic tissues. mRNA profiles of Drosophila melanogaster brains from adult males and females from a European and an African population (2 biological replicates each)
2012-11-21 | E-GEOD-40907 | biostudies-arrayexpress
Project description:Eye-stalks of some flies exhibit extreme sexual dimorphism, but little is known about the genetic mechanisms producing variation in these ornamental traits. Therefore, we constructed an EST database of genes expressed in the developing eye-antennal imaginal disc of the highly dimorphic species, Teleopsis dalmanni, and used this set of genes to construct high density oligoarrays and compare patterns of gene expression between lines of flies selected for divergent eyespan. Microarray experiments using eye-antennal disc tissue identified over 350 genes with significant differential expression between male flies from lines selected for high and low relative eyespan but did not reveal any primary biological process or pathway that is driving the expression differences.
2009-08-22 | GSE15444 | GEO
Project description:Data from whole-body, head, thorax, abdomen, ovaries, testes and accessory glands was used to assess possible causes of a non-random distribution of sex-biased genes (sexually dimorphic expression). All samples were derived from virgin adult flies. We measured gene expression of male and female Drosophila serrata from 43 lines (whole-body) and multiple tissues sampled from outbred laboratory stock. All flies were originally samples from Brisbane, Queensland, Australia. Data from two replicates for each sex/line are presented, plus 3-5 replicates per sex/tissue. 24 adult whole-body samples were not used in analyses due to poor quality, giving a total of 176 arrays.
2013-11-05 | E-GEOD-45801 | biostudies-arrayexpress
Project description:Sexually dimorphic traits are by definition exaggerated in one sex, which may arise from a history of sex-specific selection â in males, females, or both. If this exaggeration comes at a cost, exaggeration is expected to be greater in higher condition individuals (condition-dependent). Although studies using small numbers of morphological traits are generally supportive, this prediction has not been examined at a larger scale. We test this prediction across the trancriptome by determining the condition-dependence of sex-biased (dimorphic) gene expression. We find that high-condition populations are more sexually dimorphic in transcription than low-condition populations. High condition populations have more male-biased genes and more female-biased genes, and a greater degree of sexually dimorphic expression in these genes. Also, condition-dependence in male-biased genes was greater than in a set of unbiased genes. Interestingly, male-biased genes expressed in the testes were not more condition-dependent than those in the soma. By contrast, increased female-biased expression under high condition may be have occurred because of the greater contribution of the ovary-specific transcripts to the entire mRNA pool. We did not find any genomic signatures distinguishing the condition-dependent sex-biased genes. The degree of condition-dependent sexual dimorphism (CDSD) did not differ between the autosomes and the X-chromosome. There was only weak evidence that rates of evolution correlated with CDSD. We suggest that the sensitivity of both female-biased genes and male-biased genes to condition may be akin to the overall heightened sensitivity to condition that life-history and sexually selected traits tend to exhibit. Our results demonstrate that through condition-dependence, early life experience has dramatic effects on sexual dimorphism in the adult transcriptome. There were 8 biologically distinct samples. Each was replicated 6 times for a total of 48 biological samples on 24 arrays. There was no reference or control sample as a loop design was used. Each of the 48 samples are represented separately.
2010-01-31 | E-GEOD-19973 | biostudies-arrayexpress
Project description:Background: Changes in gene regulation are thought to be crucial for the adaptation of organisms to their environment. Transcriptome analyses can be used to identify candidate genes for ecological adaptation, but can be complicated by variation in gene expression between tissues, sexes, or individuals. Here we use high-throughput RNA sequencing of a single Drosophila melanogaster tissue to detect brain-specific differences in gene expression between the sexes and between two populations, one from the ancestral species range in sub-Saharan Africa and one from the recently colonized species range in Europe. Results: Relatively few genes (<100) displayed sexually dimorphic expression in the brain, but there was an enrichment of sex-biased genes, especially male-biased genes, on the X chromosome. Over 340 genes differed in brain expression between flies from the African and European populations, with the between-population divergence being highly correlated between males and females. The differentially expressed genes include those involved in stress response, olfaction, and detoxification. Expression differences were associated with transposable element insertions at two genes implicated in insecticide resistance (Cyp6g1 and CHKov1). Conclusions: Analysis of the brain transcriptome revealed many genes differing in expression between populations that were not detected in previous studies using whole flies. There was little evidence for sex-specific regulatory adaptation in the brain, as most expression differences between populations were observed in both males and females. The enrichment of genes with sexually dimorphic expression on the X chromosome is consistent with dosage compensation mechanisms affecting sex-biased expression in somatic tissues.
2012-11-21 | GSE40907 | GEO