Differential gene expression in ovaries of Qira black sheep and Hetian sheep using RNA-Seq technique.

The Qira black sheep and the Hetian sheep are two local breeds in the Northwest of China, which are characterized by high-fecundity and low-fecundity breed respectively. The elucidation of mRNA expression profiles in the ovaries among different sheep breeds representing fecundity extremes will helpful for identification and utilization of major prolificacy genes in sheep. In the present study, we performed RNA-seq technology to compare the difference in ovarian mRNA expression profiles between Qira black sheep and Hetian sheep. From the Qira black sheep and the Hetian sheep libraries, we obtained a total of 11,747,582 and 11,879,968 sequencing reads, respectively. After aligning to the reference sequences, the two libraries included 16,763 and 16,814 genes respectively. A total of 1,252 genes were significantly differentially expressed at Hetian sheep compared with Qira black sheep. Eight differentially expressed genes were randomly selected for validation by real-time RT-PCR. This study provides a basic data for future research of the sheep reproduction.

Identification of SNPs within the sheep PROP1 gene and their effects on wool traits.

Regarding mutations of PROP1 (Prophet of POU1F1) gene significantly associating with combined pituitary hormone deficiency (CPHD) in human patients and animals, PROP1 gene is a novel important candidate gene for detecting genetic variation and growth, reproduction, metabolism traits selection and breeding. The aim of this study was to detect PROP1 gene mutation of the exon 1-3 and its association with wool traits in 345 Chinese Merino sheep. In this study, on the basis of PCR-SSCP and DNA sequencing methods, ten novel SNPs within the sheep PROP1 gene, namely, AY533708: g.45A>G resulting in Glu15Glu, g.1198A>G, g.1341G>C resulting in Arg63Ser, g.1389G>A resulting in Ala79Ala, g.1402C>T resulting in Leu84Leu, g.1424A>G resulting in Asn91Ser, g.1522C>T, g.1556A>T, g.1574T>C, g.2430C>G were reported. In addition, association analysis showed that three genotypes of P4 fragment were significantly associated with fiber diameter in the analyzed population (P=0.044). These results strongly suggested that polymorphisms of the PROP1 gene could be a useful molecular marker for sheep breeding and genetics through marker-assisted selection (MAS).