title: Gene expression of chicken gonads is sex- and side-specific.
abstract: In chicken, the left and right female gonads undergo a completely different program during development. To learn more about the molecular factors underlying side-specific development and to identify potential sex- and side-specific genes in developing gonads, we separately performed next-generation sequencing-based deepSuperSAGE transcription profiling from left and right, female and male gonads of 19-day-old chicken embryos. A total of 836 transcript variants were significantly differentially expressed (p < 10(-5)) between combined male and female gonads. Left-right comparison revealed 1,056 and 822 differentially (p < 10(-5)) expressed transcript variants for male and female gonads, respectively, of which 72 are side-specific in both sexes. At least some of these may represent key players for lateral development in birds. Additionally, several genes with laterally differential expression in the ovaries seem to determine female gonads for growth or regression, whereas right-left differences in testes are mostly limited to the differentially expressed genes present in both sexes. With a few exceptions, side-specific genes are not located on the sex chromosomes. The large differences in lateral gene expression in the ovaries in almost all metabolic pathways suggest that the regressing right gonad might have undergone a change of function during evolution.
authors.affiliation: Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt am Main, Frankfurt/M., Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Scheider
authors.forename: Fabian
authors.initials: F
authors.lastname: Afonso-Grunz
authors.forename: Klaus
authors.initials: K
authors.lastname: Hoffmeier
authors.forename: Ralf
authors.initials: R
authors.lastname: Horres
authors.forename: Florian
authors.initials: F
authors.lastname: Groher
authors.forename: Lukas
authors.initials: L
authors.lastname: Rycak
authors.forename: Jörg
authors.initials: J
authors.lastname: Oehlmann
authors.forename: Peter
authors.initials: P
authors.lastname: Winter
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006066:Gonads / Q000196:embryology* / Q000378:metabolism; D008297:Male; D010053:Ovary / Q000378:metabolism; D012727:Sex Characteristics; D012733:Sex Differentiation / Q000235:genetics; D013737:Testis / Q000378:metabolism; D059467:Transcriptome