Screening And Analysis Of Differentially Expressed Genes In Ovary Of Anhui White Goat

Goats [Capra hircus) are one of the important economical animals, as they provide high-quality leather, wool and animal protein. The lambing rates in goats are low, and heritability is also low in this species, which restricts breeding. There has been an increasing demand for goat mutton and consequent rapid development of the goat industry in recent years for which traditional breeding methods have not been adequate. The Anhui white goat (AWG) is known for its precocious puberty and higher fertility, compared with other types of goat. AWG ewes can estrous all the year round, and lamb twice in one year or three times in two years with high lambing rate. AWG is therefore an ideal model for the study of goat breeding traits. There has been some recent progress in characterizing the major genes involved in the prolificacy of sheep. Such information however is still relatively limited in the goat. In this the present study, estrus ovary ovaries of multiparous and uniparous AWGs were selected as experimental material to detect sampled in order to analyze the differential expression of genes between them using RNA-Seq (Quantification). The aim of this analysis was to screen for major genes which that control high prolificacy, and provided a theoretical basis for the molecular breeding in goat.Experiment Ⅰ:Screening and analysis differentially expressed genes (DEG) in the ovaries of uniparous and multiparous AWG.To investigate the genes associated with high fecundity in the Anhui white goat, six adult ewes (three multiparous and three uniparous) were randomly selected based on breeding records from the previous five years, and their ovaries were used to do high-throughput sequencing through the RNA-Seq (Quantification) method. This analysis generated more than 5,900,000 raw reads in uniparous and multiparous libraries, and the percentages of clean reads among the raw reads reached 98.60% and 98.16% in the two libraries, respectively. A total of 15890 genes were detected, and 2201 genes were differentially expressed (FDR≤0.001 and |log2Ratio|≥1) between the uniparous and multiparous libraries, in which 1583 genes were upregulated and 618 genes were downregulated in multiparous library. Differentially expressed genes were involved in the 50 GO categories and the terms cellular process, cell & cell part and binding were predominant in each of the three main categories, respectively. KEGG pathway significant enrichment analysis found revealed that the DEGs were participated in 244 pathways, and enriched in 11 signaling pathway (Qvalue<0.05), including ECM-receptor interactions, focal adhesion, regulation of the actin cytoskeleton and so on. Quantitative real-time RT-PCR confirmed the differential expression of ten genes. After the bioinformatic analysis, a total of 12 genes which may be associated with high prolificacy of goats were screened out, and FER1L4, GVINP1, GVIN1, Itga4 and OPN msy be the key candidate genes. These results offer a list of new candidate genes to explore the goat prolificacy and thus provide a foundation for further molecular studies in the future.Experiment Ⅱ:Expression profiling of FER1L4 and SRD5A2 genes in different tissues of the goats.To further analyze the relationship between genes differentially expressed and high fecundity in goats, nine adult ewes (three uniparous Anhui White Goat, three multiparous Anhui White Goat and three Boer Goat) were randomly selected, the heart, liver, spleen, lung, kidney, muscle, ovaries, fallopian tubes, uterus and small intestine were collected, and analysis the Expression profiling of FER1L4 and SRD5A2 genes in these tissues. The results showed that:the expression of the two genes present tissue specificity. FER1L4 was expressed in the ovaries, but almost didn’t express in the heart, kidney, uterus of AWG and Boer goat. SRD5A2 was expressed in the ovaries, but almost didn’t express in the heart, lung, uterus and small intestine of AWG and Boer goat. And SRD5A2 was specific high expressed in the liver of uniparous AWG and Boer goat. These results indicated that FER1L4 and SRD5A2 gene may be associated with high fecundity in Anhui White Goat, but their relationship with fecundity in Boer goat is not clear, and the further research is necessary.