ArrayExpress

Released on 18 May 2010, last updated on 27 March 2012

Gallus gallus

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).

transcription profiling by array 

Stephanie C Bannister <stephanie.bannister@csiro.au>, Andrew H Sinclair, Craig A Smith, Mark L Tizard, Timothy J Doran

Sexually dimorphic microRNA expression during chicken embryonic gonadal development. Bannister SC, Tizard ML, Doran TJ, Sinclair AH, Smith CA.