title: MicroRNA Expression Profile in Bovine Granulosa Cells of Preovulatory Dominant and Subordinate Follicles during the Late Follicular Phase of the Estrous Cycle.
abstract: In bovine, ovarian follicles grow in a wave-like fashion with commonly 2 or 3 follicular waves emerging per estrous cycle. The dominant follicle of the follicular wave which coincides with the LH-surge becomes ovulatory, leaving the subordinate follicles to undergo atresia. These physiological processes are controlled by timely and spatially expressed genes and gene products, which in turn are regulated by post-transcriptional regulators. MicroRNAs, a class of short non-coding RNA molecules, are one of the important posttranscriptional regulators of genes associated with various cellular processes. Here we investigated the expression pattern of miRNAs in granulosa cells of bovine preovulatory dominant and subordinate follicles during the late follicular phase of bovine estrous cycle using Illumina miRNA deep sequencing. In addition to 11 putative novel miRNAs, a total of 315 and 323 known miRNAs were detected in preovulatory dominant and subordinate follicles, respectively. Moreover, in comparison with the subordinate follicles, a total of 64 miRNAs were found to be differentially expressed in preovulatory dominant follicles, of which 34 miRNAs including the miR-132 and miR-183 clusters were significantly enriched, and 30 miRNAs including the miR-17-92 cluster, bta-miR-409a and bta-miR-378 were significantly down regulated in preovulatory dominant follicles. In-silico pathway analysis revealed that canonical pathways related to oncogenesis, cell adhesion, cell proliferation, apoptosis and metabolism were significantly enriched by the predicted target genes of differentially expressed miRNAs. Furthermore, Luciferase reporter assay analysis showed that one of the differentially regulated miRNAs, the miR-183 cluster miRNAs, were validated to target the 3'-UTR of FOXO1 gene. Moreover FOXO1 was highly enriched in granulosa cells of subordinate follicles in comparison with the preovulatory dominant follicles demonstrating reciprocal expression pattern with miR-183 cluster miRNAs. In conclusion, the presence of distinct sets of miRNAs in granulosa cells of preovulatory dominant and subordinate follicles supports the potential role of miRNAs in post-transcriptional regulation of genes involved in bovine follicular development during the late follicular phase of the estrous cycle.
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Samuel
authors.initials: S
authors.lastname: Gebremedhn
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Dessie
authors.initials: D
authors.lastname: Salilew-Wondim
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Ijaz
authors.initials: I
authors.lastname: Ahmad
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Sudeep
authors.initials: S
authors.lastname: Sahadevan
authors.affiliation: Department of Animal Breeding & Genetics, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
authors.forename: Md Munir
authors.initials: MM
authors.lastname: Hossain
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hoelker
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Franca
authors.initials: F
authors.lastname: Rings
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Neuhoff
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Ernst
authors.initials: E
authors.lastname: Tholen
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Looft
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Schellander
authors.affiliation: Institute of Animal Science, Dept. Animal Breeding and Husbandry, University of Bonn, Endenicher Allee 15, 53115 Bonn, Germany.
authors.forename: Dawit
authors.initials: D
authors.lastname: Tesfaye
mesh_terms: D000818:Animals; D002417:Cattle; D004971:Estrus; D005260:Female; D005498:Follicular Phase; D020869:Gene Expression Profiling; D006107:Granulosa Cells / Q000378:metabolism*; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000235:genetics*
chemical_list: D035683:MicroRNAs