Project description:A new online resource (flyatlas.org) provides the most comprehensive view yet of expression in multiple tissues of Drosophila. Meta-analysis of the data reveals that a significant fraction ofthe genome is expressed with great tissue specificity in the adult, demonstrating the need for the functional genomic community to embrace a wider range of functional phenotypes. Well-known developmental genes are often re-used in surprising tissues in the adult, suggesting new functions. The homologues of many human genetic disease loci show selective expression in Drosophila tissues with function analogous to the affected tissues in the cognate human disease, providing a useful filter for potential candidate genes. Experiment Overall Design: FlyAtlas is composed of data covering 8 distinct adult tissues (brain, head, midgut, Malpighian tubules,hindgut, testis, ovary, male accessory glands) so far, together with two larval tissues (tubule, fat body), each run with 4 replicates on Affymetrix Dros Genome 2 chips (with probesets for 18770 transcripts), and compared with a matched whole-fly sample.
Project description:Recent studies have revealed key roles of non-coding RNAs in sex-related pathways, but little is known about the evolutionary forces acting on these non-coding RNAs. We used whole-genome tiling arrays to profile the transcriptome of Drosophila melanogaster tissues and found that 15% of male-biased transcribed fragments (transfrags) are intergenic non-coding RNAs (incRNAs), suggesting a potentially important role for incRNAs in sex-related biological processes. Statistical analysis revealed a paucity of male-biased incRNAs and coding genes on the X chromosome, suggesting that similar evolutionary forces could be affecting the genomic organization of both coding and non-coding genes. Expression profiling across germline and somatic tissues further suggests that both male meiotic sex chromosome inactivation (MSCI) and sexual antagonism contribute to the chromosomal distribution of male-biased incRNAs. Comparative sequence analysis shows that the evolutionary age of male-biased incRNAs is a significant predictor of their chromosomal locations. In addition to identifying abundant sex-biased incRNAs in fly genome, our work unveils a global picture of the complex interplay between non-coding RNAs and sexual chromosome evolution. We used whole-genome tiling arrays to assess sex-biased transcription in D. melanogaster adult whole bodies, and testis, ovary, and accessory gland samples. Gut and thorax, tissues expected to exhibit little or no sex-biased expression, were included as controls. Expression was measured in 2-4 replicates for each tissue.
Project description:Purpose: Accurate identification of sex-biased genes requires precise measurement of gene expression levels in gonads. This study is designed to provide such data for various Drosophila species to enhance studies of sex-biased gene expression and evolution across the genus. Methods: Virgin flies were collected and aged 6-10 days before dissecting 2-3 replicates of testes or ovaries. Total RNA was extracted using the Arcturus® PicoPure® kit . Illumina® TruSeq® RNA library kits were used to poly-A+ select and reverse-transcribe mRNA, shear cDNA into ~120 bp fragments, and produce libraries for 1x50 bp sequencing on an Illumina GAIIx or HiSeq2000. Illumina®’s Real Time Analysis v1.13 module processed images, called bases, and provided base qualities. Reads were mapped to the current reference genomes using Bowtie v2.1.0 (Langmead and Salzberg, 2012, Nat Meth) with default settings. Differentially expressed genes were detected using Cufflinks v 2.1.0 (Trapnell et al., 2010, Nat Biotech; default settings) or edgeR (Robinson et al., 2010, Bioinformatics; full-quantile GC-content normalization and full-quantile between-sample normalization). Genes were called differentially expressed at a Benjamini-Hochberg false discovery rate of 0.01. Results: Thousands of male- and female-biased genes were detected for each species using both DE detection methods. These results provide a significant improvement in sensitivity of sex-biased gene detection relative to using whole-body RNA-sequencing data. These data provide a foundation for accurate identification of sex-biased genes throughout the Drosophila genus. Testis and ovary samples from Drosophila species were sequenced 1 x 50 bp in duplicate from 6-10 day old virgin, Wolbachia-free adult flies on an Illumina GAIIx or HiSeq2000.
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.
Project description:It is now well established that mature mammalian spermatozoa carry a population of mRNA molecules, at least some of which are transferred to the oocyte at fertilisation. However, the function of the sperm transcriptome remains largely unclear. To shed light on the evolutionary conservation of this feature of sperm biology, we analysed highly purified populations of mature sperm from the fruitfly, Drosophila melanogaster. As with mammalian sperm, we found a consistently enriched population of mRNA molecules that are not likely to be derived from contaminating somatic cells or immature sperm. Using tagged transcripts for three of the spermatozoal mRNAs, we demonstrate that they are transferred to the oocyte at fertilisation and can be detected at least until the onset of zygotic gene expression. We find a remarkable conservation in the functional annotations associated with fly and human spermatozoal mRNAs, in particular a highly significant enrichment for transcripts encoding Ribosomal Proteins. The identification of a conserved set of spermatozoal transcripts opens the possibility of using the power of Drosophila genetics to address the function of this enigmatic class of molecules. Overall design: RNA extracted from three biological replicates of purified sperm (Sperm rep1, Sperm rep2 and Sperm rep3) was used as a template for oligo-dT-primed reverse transcription, amplification, labelling of dye swapped technical replicates and hybridisation to long oligonucleotides microarrays. As a control, RNA from two biological replicates of dissected adult testis plus accessory glands (Testis_rep1, Testis_rep2) was amplified, labelled (dye-swap technical replicate) and hybridised to similar arrays. To help with the spot-finding of the arrays genomic DNA was co-hybridised in some cases (this genomic DNA data was excluded from further analysis). Genes with an intensity level below 200 in at least one channel across the Sperm or Testis set were removed (5579 transcripts present in all three sperm replicates, 5358 transcripts from the testis/accessory gland samples and 4295 transcripts common to both data sets). Then the quantile normalisation was independently applied to the Sperm replicate samples and Testis replicates.
Project description:In this study, three small RNA libraries constructed from gonad tissues of XX female, XY male and YY super-male yellow catfish were sequenced by Solexa high-throughput sequencing technology to investigate the expression pattern of sex-biased microRNA. The sequencing data generated a total of 384 conserved miRNAs and 113 potential novel miRNAs, among which 23, 30 and 14 miRNAs were specifically detected in XX ovary, XY testis, and YY testis, respectively. Interestingly, more abundant piRNAs were found in ovary compared to testis in yellow catfish, which phenomenon is also observed in other fish species but opposite in mammalians. We detected a number of microRNAs differentially expressed between ovary and testis, such as miR-21, miR-462, miR-430 and -200 family. When compared the transcriptome between XY and YY testis, we observed relative lower expression of miR-141 and miR-429 in YY testis. Histological analysis indicated that YY super-males have more spermatids and less spermatocytes in spermatogenic cyst than XY males under the same age and culturing conditions. The expression level of miR-141 and 429 coincides with the progression of spermatogenesis both in yellow catfish and human. At last, The expression pattern of nine arbitrarily selected miRNAs detected by quantitative RT-PCR was consistent with the Solexa sequencing results. Our study provides a comprehensive miRNA transcriptome analysis for gonad of yellow catfish with different sex genotypes, and identifies a number of sex-biased miRNAs that are potentially involved in sex differentiation and spermatogenesis. Overall design: Examination of small RNA expression profilings in yellow catfish gonads of three sex genotypes
Project description:Despite increasing efforts in miRNAs identification across various species and diverse tissue types, little is known about porcine gonad-specific miRNAs. Although the well-known importance of pig in agriculture, as well as a model for human biology, the miRNA catalog of pig has been largely undefined. Identification and preliminary characterization of gonad-specific miRNAs would be a prerequisite for a thorough understanding of their roles in regulating folliculogenesis and spermatogenesis. In the present study, we get insight into miRNA transcriptome in adult porcine ovary and testis using deep sequencing technology, and to elucidate their characteristic organ- and gender-specific profiles, genomic context and emphasize the features of X-linked miRNAs. Overall design: Two small RNA libraries from adult porcine ovary and testis tissues were sequenced.