Identification of lncRNAs Differentially Expressed during Natural and Induced Estrus in Sheep

Abstract

Background: The manipulation of the estrous cycle or induction of estrus is a commonly used technique in sheep industry. The goal of this study was to identify and characterize differences of non-coding RNAs (lincRNAs) expression between induced estrus and natural estrus using the BGISEQ-500 plat form in 7 Mongolian sheep, which will provide insights into the regulation mechanisms of lncRNAs in different reproduction mode of sheep. Methods: During the late spring, ovarian, pituitary, hypothalamic, pineal and uterine tissue samples were collected from four artificially induced estrus and three naturally estrus Mongolian sheep. Total RNA was extracted from the five tissues using TRIzol reagent (Invitrogen) and treated with DNase I following the manufacturer’s instructions. A total of 35 sheep samples were sequenced using the BGISEQ-500 plat form. Bioinformatics methods were used to analysis expression difference analysis between groups, SNP and InDel, alternative splicing, lncRNA’s miRNA precursor prediction, lncRNA target gene and family prediction. Result: 211 novel lncRNAs were systematically identified using RNA-Seq technology. Meanwhile, we found that there are diversifications of lncRNAs in induced estrus vs. nature estrus of ewes. Therefore, we predict that, under the action of exogenous hormones, many physiological processes of ewes may be affected to varying degrees through the change of LncRNA to a variety of pathways.