BACKGROUND: Small antral follicles as the final reserve of folliculogenesis, are existed throughout the reproductive life span of sheep. However, the ovarian cycles of ewe cease in the anestrus phase. This study was aimed to elucidate the ovarian small antral follicles transcriptome in the ewe’s anestrus phase.

METHODS: Granulosa cells of small antral follicles (≤3 mm) were collected from two groups of Mehraban ewes under long days of summer in the non-breeding season as anestrus phase. Transcriptome profiling of these granulosa cells were obtained using the RNA-Seq technology. An integrative analysis was utilized to identify key regulatory genes which may have potential impacts on intra-ovarian molecular activities.

RESULTS: Globally, 14506 genes were expressed whose higher expressions belonged to genes that encoded ribosomal proteins. Top significant terms of gene ontology were pertained to protein translational processes. Apart of this, most of highly significant terms were also relevant to apoptotic process through extracellular vesicles, including apoptotic bodies and exosomes. Regarding to node effect property, UBA52 (ubiquitin A-52 residue ribosomal protein fusion product 1) and RPS5 (ribosomal proteins S5) contained in highest out-degree and in-degree, respectively.

CONCLUSION: Our data suggest that ribosomal mRNA/proteins could make the granulosa cells undergo a lot of changes from the point of view that ovarian activities are ceased in the anestrus phase.