BioProject

The preservation of locally endangered breeds is essential for ecosystem services that affect both society and the environment. More...

The preservation of locally endangered breeds is essential for ecosystem services that affect both society and the environment. Reproductive fitness becomes a crucial consideration in this regard. MicroRNAs (miRNAs) are small noncoding RNA molecules with a key role in post-transcriptional regulation. They usually act in tissues, where they are produced, but when released in extracellular fluid, they are termed circulating miRNAs (c-miRNAs). C-miRNAs might be potential biomarkers, whose profile changes under different physiological states. The purpose of this work is to establish a connection between distinctive variations in c-miRNAs’ expression and specific estrus cycle phases in Frabosana-Roaschina sheep, an endangered Piedmontese breed. Two trials of twenty ewes with different reproductive efficiency (nulliparous in the first trial, pluriparous in the second trial) were sampled on alternate days, after synchronization, for blood, saliva and feces. Ultrasound scans were performed during the induced estrus cycle. Animals were also video recorded to assess behaviors. Play behaviors and no sexual behaviors were detected in the first trial; sexual behaviors and no play behaviors in the second one. Based on plasma trends of 17β-estradiol and progesterone and ultrasound images, two moments were identified for miRNAs analyses: the beginning of the follicular phase (day 2) and the beginning of luteal phase (day 11). C-miRNAs of 6 representative animals from second trial were sent to be sequenced. Analyses on the sequencing data have highlighted twelve c-miRNAs differentially expressed (DE), comparing day 11 with day 2: five miRNAs resulted upregulated, whereas seven miRNAs are downregulated. An enrichment analysis, based on predicted targets, using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases was performed. Many of these genes regulate reproductive pathways with the possible involvement of miRNAs. In the end, qRT-PCR validation of DE miRNAs in all ewes was performed and differences in gene expression between the two sampling points and the two trials emerged, in line with literature. The investigation of these miRNAs’ involvement in the regulation of the estrus could improve reproductive performance and welfare of Frabosana-Roaschina. Overall design: 20 pluriparous ewes of Frabosana-Roaschina ewes were recruited. Animals were synchronized with a standardised protocol using progesterone sponges. Blood samples were collected every 2 days after sponge removal and 6 representative animals were chosen. Two time points were selected: 2 days and 11 days after removal of progesterone sponges corresponding to the beginning of the follicular phase and the luteal phase respectively. microRNA were extracted from plasma and sequenced. Less...