Project description:Gene dosage imbalance of heteromorphic sex chromosomes (XY or ZW) exists between the sexes, and with the autosomes. Mammalian X chromosome inactivation was long thought to imply a critical need for dosage compensation in vertebrates. However, mRNA abundance measurements that demonstrated sex chromosome transcripts are neither balanced between the sexes or with autosomes in monotreme mammals or birds brought sex chromosome dosage compensation into question. This study examines transcriptomic and proteomic levels of dosage compensation in platypus and chicken compared to mouse, a model eutherian species. We analyzed mRNA and protein levels in heart and liver tissues of chicken, mouse and platypus.
Project description:MicroRNAs (miRNAs) are a highly conserved class of small RNAs which function in a sequence-specific manner to post-transcriptionally regulate expression of target genes. Tissue-specific miRNA expression studies have discovered numerous functions for miRNAs in various aspects of embryonic development, but a role for miRNAs in gonadal development and sex differentiation has not yet been reported. Using the chicken embryo as a vertebrate model, differential miRNA expression between male and female embryonic gonads, was analysed at three developmental stages (embryonic days (E) 5.5, E6.5 and E9.5), using custom-designed 4x2K CombiMatrix miRNA microarray. The aims of this study were to: 1-identify miRNAs differentialy expressed by sex; 2-identify sex-specific miRNAs; 3-analyse global changes in miRNA up-regulation in male versus female gonads before, during and after the histological onset of sexual differentiation. This study provides a basis for establishing whetehr miRNAs are involved in either initiating or regulating vertebrate gonadal sex differentiation. Keywords: miRNA, sex comparison, developmental stage comparison.
Project description:MicroRNAs (miRNAs) are a highly conserved class of small RNAs which function in a sequence-specific manner to post-transcriptionally regulate expression of target genes. Tissue-specific miRNA expression studies have discovered numerous functions for miRNAs in various aspects of embryonic development, but a role for miRNAs in gonadal development and sex differentiation has not yet been reported. Using the chicken embryo as a vertebrate model, differential miRNA expression between male and female embryonic gonads, was analysed at three developmental stages (embryonic days (E) 5.5, E6.5 and E9.5), using custom-designed 4x2K CombiMatrix miRNA microarray. The aims of this study were to: 1-identify miRNAs differentialy expressed by sex; 2-identify sex-specific miRNAs; 3-analyse global changes in miRNA up-regulation in male versus female gonads before, during and after the histological onset of sexual differentiation. This study provides a basis for establishing whetehr miRNAs are involved in either initiating or regulating vertebrate gonadal sex differentiation. Keywords: miRNA, sex comparison, developmental stage comparison. miRNA samples from male and female embryonic chicken gonads from three developmental stages: embryonic day (E) 5.5 (Hamilton & Hamburger (HH) stage 27-28), E6.5 (HH stage 29-30) & E9.5 (HH stage 35-36). Samples are listed with biological replicates used for analysis in brackets following: 1 - Male E5.5 (5); 2 - Female E5.5 (4); 3 - Male E6.5 (5); 4 - Female E6.5 (3); 5 - Male E9.5 (4); 6 - Female E9.5 (4).
Project description:We report the proteomic characterization of gonads from wild P. lividus collected along coastal Sardinia, and describe the changes occurring in gonads according to sex and developmental stage. Gonads in the recovery, pre-mature, mature, and spent stages were analyzed using a shotgun proteomics approach based on filter-aided sample preparation followed by tandem mass spectrometry and label-free differential analysis. A detailed characterization of the proteome changes occurring in gonads of both sexes along maturation was achieved. Significant changes were seen in numerous proteins involved in nutrient accumulation and in gamete biology and maturation. Adding to an improved understanding of the P. lividus reproductive cycle in its natural environment, the results described in this work form the basis for defining novel protein markers and procedures for an easier sexing and staging, and for monitoring sea urchin gonad maturation in aquaculture plants.
Project description:Sex chromosomes are characterized by a non-random content of genes with preferential expression in one sex. The mechanisms which are responsible for this phenomenon are, however, largely unresolved. To elucidate selective forces shaping the Z chromosome gene content in chicken, we analyzed microarray data from adult and embryonic gonads (the latter already available in GEO Series GSE8693).
Project description:Gonadal sex differentiation – testis versus ovary formation – is a fundamental process required for reproduction and evolution. Reflecting this importance, the embryonic gonads of vertebrate species comprise the same key cell types; germ cells, supporting cells and interstitial steroidogenic cells. Remarkably, the genetic triggers for gonadal sex differentiation vary across species (the SRY gene in mammals, DMRT1 in birds and some turtles, temperature in many reptiles, AMH and various other genes in fishes). Despite this variation, the cell biology of gonadal development was long thought to be largely conserved. Here, we present a comprehensive analysis of gonadal sex differentiation, using the chicken embryo as a model and considering the entire gonad. We sampled over 30,000 cells across several developmental stages, prior, during and after the onset of gonadal sex differentiation. The data provide several new insights into cell lineage specification during vertebrate gonadogenesis. Combining lineage tracing with single cell transcriptomics, the data show that somatic supporting cells of the embryonic chicken gonad do not derive from the coelomic epithelium, in contrast to other vertebrates studied. Instead, the early somatic precursors cells of the gonads in both sexes derive from a DMRT1+/PAX2+/WNT4+/OSR1+ mesenchymal cell population. In particular, PAX2 marks immigrating mesenchymal cells that give rise to the supporting cell lineage. We find a greater complexity of gonadal cell types than previously thought, including the identification of two distinct sub-populations of Sertoli cells in developing testes, and derivation of embryonic steroidogenic cells from a differentiated supporting cell lineage. We provide significantly improved resolution of gonadal cell types and identify several new gonadal marker genes. Altogether, these results indicate that, just as the genetic trigger for sex differs across vertebrate groups, cell lineage specification in the gonad may also vary substantially.
Project description:Gene expression profiling of FACS sorted GFP+ve cells from sexed gonads of transgenic pSF1-eGFP mice Keywords: Time course and comparison of sexes
Project description:Sex chromosomes are characterized by a non-random content of genes with preferential expression in one sex. The mechanisms which are responsible for this phenomenon are, however, largely unresolved. To elucidate selective forces shaping the Z chromosome gene content in chicken, we analyzed microarray data from adult and embryonic gonads (the latter already available in GEO Series GSE8693). Experiment Overall Design: Total RNA from gonads of 8 males and 8 females was used for hybridization to Affymetrix GeneChip® Chicken Genome Arrays. Prior to hybridization the samples were combined in equal quantities into 4 pools (4 testes/ovary samples in each pool), 2 of them representing testis and 2 ovary. Experiment Overall Design: All four GeneChips met Affymetrix quality control criteria. Furthermore, all chips were checked by methods based on probe level robust linear model fitting provided by "affyPLM" package (Bolstad, 2007). None of the chips showed any signs of abnormality.