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: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:In poultry, in vitro derived primordial germ cells (PGCs) represent an important tool for management of genetic resources. However, several studies have highlighted sexual differences exhibited by PGCs through in vitro steps, which may compromise their reproductive capacities. To understand this phenomenon, we compared the proteome of pregonadal chicken male (ZZ) and female (ZW) PGCs expanded in vitro by quantitative proteomic analysis using a GeLC-MS/MS strategy. The proteins found to be differentially abundant in chicken male and female PGCs indicated their early sexual identity. Many of the proteins up-accumulated in male PGCs were encoded by genes strongly enriched in the sexual chromosome Z. This suggests that the known lack of dosage compensation of the transcription of Z-linked genes between sexes persists at protein level in PGCs, and that this may be a key factor of their autonomous sex differentiation. Male and female PGCs up-accumulated protein sets were associated with differential biological processes, and contained proteins biologically relevant for male and female germ cell development respectively. This study presents first evidence on early predetermined sex specific cell fate of chicken PGCs that will help to understand their sexual physiological specificities and enable more precise sex-specific adaptation of in vitro culture conditions.
Project description:Before the onset of sexual differentiation, male and female external genitalia are morphologically indistinguishable. After the onset of sex-specific production of sex steroids by the gonads, the male and female external genitalia differentiate into either a penis or clitoris. Here we use single cell sequencing to investigate the similarities and differences of cell populations in the external genitalia during the critical sexual differentiation window in the mouse embryo. We found the male and female genitalia are largely similar in cell composition and gene expression at the bipotential stage of development. As sexual differentiation ensues, sex steroid-dependent and -independent differences in cell populations arise, leading to dimorphic establishment of the external genitalia.
Project description:The aim of this study was to study the gene expression profile in developing female and male gonads of Xenopus laevis at four stages: at the Nieuwkoop-Faber stage 50 (genital ridge), at NF53 (sex-determining period), NF56 (the onset of sexual differentiation), NF62 (gonads sexually differentiated).
Project description:Biological bases for sexual differences in the brain exist in a wide range of vertebrate species, including the chicken. We examined whether sexually dimorphic gene expression in the brain precedes gonadal differentiation. Using the Affymetrix GeneChip® Chicken Genome Array, we identified many female- and male-enhanced genes that are differentially expressed in sex-specific brains from stage 29 chicken embryos. We postulate that these genes have potential roles in the sexual differentiation of neural function and development in chickens.
Project description:Biological bases for sexual differences in the brain exist in a wide range of vertebrate species, including the chicken. We examined whether sexually dimorphic gene expression in the brain precedes gonadal differentiation. Using the Affymetrix GeneChip® Chicken Genome Array, we identified many female- and male-enhanced genes that are differentially expressed in sex-specific brains from stage 29 chicken embryos. We postulate that these genes have potential roles in the sexual differentiation of neural function and development in chickens. Experiment Overall Design: All analyses were performed in triplicate. The Affymetrix data from male and female brain samples at stage 29 were generated. The male and female brain samples by genetic sexing were pooled and homogenized. Pooled samples ranged from 5 to 8 embryos. 4g of total RNA from the pooled samples was used for labeling. Probe synthesis from total RNA samples, hybridization, detection, and scanning were performed according to standard protocols from Affymetrix.