Microarray analysis of stalk-eyed fly lines selected for divergent eyespan
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ABSTRACT:
ORGANISM(S): Teleopsis dalmanni
PROVIDER: GSE15444 | GEO | 2009/08/22
SECONDARY ACCESSION(S): PRJNA115807
REPOSITORIES: GEO
Similar Datasets
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: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. Two-condition experiment, female vs. male RNA using larval eye discs and adult heads for one species (Teleopsis quinqueguttata)
2014-01-01 | E-GEOD-46694 | biostudies-arrayexpress
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 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: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:We utilized Comparative Genomic Hybridization (CGH), using probes designed from de novo assembly of 10 tissues into a grand transcriptome to identify genes located on the X and Y chromosomes of a stalk-eyed fly, Teleopsis dalmanni. We use next generation sequencing of RNA to identify over 500 genes that are differentially expressed in the testes due to the effects of a driving X chromosome (XSR) in T. dalmanni. Most of these genes were X-linked, evolving more rapidly than control genes, and exhibit elevated expression in the gonads. Finally, XSR has become genetically differentiated from standard X chromosomes – using the RNA sequence data, we found nearly 1000 sites in X-linked genes and only a handful in autosomal genes where there was a fixed nucleotide difference. We conclude that XSR has led to widespread sequence and expression divergence on the X chromosome in T. dalmanni.
2014-03-06 | GSE55601 | GEO
Project description:In this study, we utilized Comparative Genomic Hybridization (CGH), using probes designed from EST sequence, to identify genes located on the X chromosome of four species in the stalk-eyed fly genus Teleopsis. Analysis of log ratio values from the CGH microarrays for over 3400 genes produces a strongly bimodal distribution that clearly differentiates autosomal from X-linked genes for all four species. Genetic mapping of 35 of these genes in T. dalmanni indicates the CGH results correctly identified chromosomal location in all cases. Syntenic comparison with Drosophila indicates that 90% of the X-linked genes in Teleopsis are homologous to genes located on chromosome 2L in D. melanogaster, suggesting the formation of a nearly complete neo-X chromosome from Muller element B in the Dipteran lineage leading to Teleopsis. Overall, this study demonstrates CGH is a useful technique for identifying chromosomal sex-linkage and should be applicable to other organisms with EST or partial genomic information.
2010-03-01 | GSE20315 | GEO
Project description:We utilized Comparative Genomic Hybridization (CGH), using probes designed from de novo assembly of 10 tissues into a grand transcriptome to identify genes located on the X and Y chromosomes of a stalk-eyed fly, Teleopsis dalmanni. We use next generation sequencing of RNA to identify over 500 genes that are differentially expressed in the testes due to the effects of a driving X chromosome (XSR) in T. dalmanni. Most of these genes were X-linked, evolving more rapidly than control genes, and exhibit elevated expression in the gonads. Finally, XSR has become genetically differentiated from standard X chromosomes M-bM-^@M-^S using the RNA sequence data, we found nearly 1000 sites in X-linked genes and only a handful in autosomal genes where there was a fixed nucleotide difference. We conclude that XSR has led to widespread sequence and expression divergence on the X chromosome in T. dalmanni. Two-condition experiment, female vs. male DNA, for one species with 4 biological replicates
2014-03-06 | E-GEOD-55601 | biostudies-arrayexpress
Project description:In this study, we utilized Comparative Genomic Hybridization (CGH), using probes designed from EST sequence, to identify genes located on the X chromosome of four species in the stalk-eyed fly genus Teleopsis. Analysis of log ratio values from the CGH microarrays for over 3400 genes produces a strongly bimodal distribution that clearly differentiates autosomal from X-linked genes for all four species. Genetic mapping of 35 of these genes in T. dalmanni indicates the CGH results correctly identified chromosomal location in all cases. Syntenic comparison with Drosophila indicates that 90% of the X-linked genes in Teleopsis are homologous to genes located on chromosome 2L in D. melanogaster, suggesting the formation of a nearly complete neo-X chromosome from Muller element B in the Dipteran lineage leading to Teleopsis. Overall, this study demonstrates CGH is a useful technique for identifying chromosomal sex-linkage and should be applicable to other organisms with EST or partial genomic information. Two-condition experiment, female vs. male DNA, for four species, each with 4 biological replicates
2010-05-06 | E-GEOD-20315 | biostudies-arrayexpress
Project description:The goal of this study was to examine chromosome topology in Drosophila larval eye and antennal discs by identifying topologically associating domains (TADs) across the genome. TADs were compared between the eye and antennal disc to determine whether they contribute to cell-type-specific homologous pairing and transvection.
2019-08-24 | GSE136267 | GEO