Yuxuan Song

Identification and Profiling of microRNAs in Goat Endometrium during Embryo Implantation

Background MicroRNAs (miRNAs) are short, highly conserved small noncoding RNAs that had fundamental roles in post-transcriptional gene expression, and they are crucial for proper control of biological processes and known to participate in embryo implantation. However, miRNA expression profiles in the pre-receptive and receptive phases of the goat endometrium during embryo implantation are unknown. Results A total of 1,069 and 847 miRNAs were expressed in receptive (R) and pre-receptive (P) goat endometrium, and 632 miRNAs were co-expressed in both phases. We identified 545 (50.98%) known miRNAs in the R library and 522 (61.63%) in the P library. There were 110 up-expressed miRNAs and 33 down-expressed miRNAs in receptive endometrium compared with the pre-receptive endometrium meeting the criteria of P-values< 0.05. Moreover, GO and KEGG analysis of the target genes of the differentially expressed miRNAs revealed some candidate miRNAs, genes and pathways that may involve in the formation of the receptive endometrium. Based on stem-loop RT-qPCR, 15 miRNAs were detected and the results suggested that the majority of the miRNA expression data measured by Solexa deep sequencing could represent actual miRNA expression levels. Conclusions Our data revealed the first miRNA profile related to the biology of the goat receptive endometrium during embryo implantation, and the results suggested that a subset of miRNAs might play important roles in the formation of endometrial receptivity. Thus, elucidating the physiological roles of endometrial miRNAs will help us better understand the genetic control of embryo implantation in goats.

Novel polymorphisms of the growth hormone gene and their effect on growth traits in Chinese goats

The polymorphisms of the growth hormone (GH) gene were analyzed in 686 individuals from four goat populations, Three haplotypes (A, B and C) and three observed genotypes (AA, AB and AC) were detected at the P2 locus, and three haplotypes (E, F and G) and three observed genotypes (EE, EF and EG) were also detected at the P4 locus. In addition, five single nucleotide polymorphisms (SNPs)-A112G, C142T (Gly>Ser), C214T (P2 locus), C266A (Pro>His) and C214T (P4 locus, Arg>Trp), were identified by GH gene sequencing and PCR-SSCP analysis. The SNPs loci were in Hardy-Weinberg disequilibrium in three goat populations (P<0.05). Association of polymorphisms with growth traits was done in BG, F1 and F1 populations, which were shown to be associated with growth traits in three goat populations. The SNPs in the goat GH gene had significant effects on growth traits (P<0.05). suggesting that the GH gene is a strong candidate gene that affects growth traits in goat.

Characterization of the Transcriptional Complexity of the Receptive and Pre-receptive Endometria of Dairy Goats.

Endometrium receptivity is essential for successful embryo implantation in mammals. However, the lack of genetic information remains an obstacle to understanding the mechanisms underlying the development of a receptive endometrium from the pre-receptive phase in dairy goats. In this study, more than 4 billion high-quality reads were generated and de novo assembled into 102,441 unigenes; these unigenes were annotated using published databases. A total of 3,255 unigenes that were differentially expressed (DEGs) between the PE and RE were discovered in this study (P-values < 0.05). In addition, 76,729–77,102 putative SNPs and 12,837 SSRs were discovered in this study. Bioinformatics analysis of the DEGs revealed a number of biological processes and pathways that are potentially involved in the establishment of the RE, notably including the GO terms proteolysis, apoptosis, and cell adhesion and the KEGG pathways Cell cycle and extracellular matrix (ECM)-receptor interaction. We speculated that ADCY8, VCAN, SPOCK1, THBS1, and THBS2 may play important roles in the development of endometrial receptivity. The de novo assembly provided a good starting point and will serve as a valuable resource for further investigations into endometrium receptivity in dairy goats and future studies on the genomes of goats and other related mammals.

Polymorphism of Exon 2 of FShβ Gene and Its Relationship with Reproduction Performance in Two Goat Breeds

Abstract The objectives of the present study were to detect the polymorphism in follicle stimulating hormone beta (FSHβ) gene and investigate the relationship between FSHβ gene and high prolificacy in goats. According to the sequence of ovine FSHβ gene, two pairs of primers were designed to detect single nucleotide polymorphism of exon 2 of FSHβ gene in two goat breeds, Xinong Saanen dairy goat and Boer goat, by PCR-SSCP. The least square mean and genetic variance of different genotypes at polymorphic locus were analyzed, and the selection reaction was forecasted by genetic correlation between marker locus and genetic variance of litter size traits. There was one polymorphic locus occurring in exon 2 (P2) with three genotypes (EE, EF and FF). In Xinong Saanen dairy goat, EE genotype had significantly higher (P

Combined effects of four SNPs within goat PRLR gene on milk production traits

Xinong Saanen (SN, n=323) and Guanzhong (GZ, n=197) goat breeds were used to detect single nucleotide polymorphisms (SNPs) in the coding regions with their intron-exon boundaries of prolactin receptor (PRLR) gene by DNA sequencing, primer-introduced restriction analysis-polymerase chain reaction (PIRA-PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). Four novel SNPs (g.40452T>C, g.40471G>A, g.61677G>A and g.61865G>A) were identified. The g.61677G>A and g.61865G>A SNPs caused amino acid variations p.Ser485Asn and p.Val548Met, respectively. Both g.40452T>C and g.40471G>A loci were closely linked in SN and GZ goat breeds (r(2)>0.33). In addition, there was also a close linkage between g.61677G>A and g.61865G>A loci in both goat breeds. Statistical results indicated that the g.40452T>C, g.61677G>A and g.61865G>A SNPs were significantly associated with milk production traits in SN and GZ breeds. Further analysis revealed that combinative genotype C1 (TTAAGGGG) was better than the others for milk yield in SN and GZ goat breeds. These results are consistent with the regulatory function of PRLR in mammary gland development, milk secretion, and expression of milk protein genes, and extend the spectrum of genetic variation of the caprine PRLR gene, which might contribute to goat genetic resources and breeding.

Polymorphism identification in the goat KITLG gene and association analysis with litter size.

This study reported the analysis of KIT ligand (KITLG) gene polymorphisms in 681 goats of three breeds: Xinong Saanen (SN), Guanzhong (GZ), and Boer (BG). In addition, the study identified three allelic variants: g.769T>C and g.817G>T in SN and GZ breeds, and g.9760G>C in the three goat breeds. The g.769T>C and g.817G>T loci were closely linked (r(2)  > 0.33). All the single nucleotide polymorphism loci were in Hardy-Weinberg disequilibrium (P < 0.05). Significant associations were found for litter size with all three loci. Therefore, these results suggest that the KITLG gene is a strong candidate gene affecting litter size in goats.

Analysis of Differentially Expressed Genes in Ovaries of Polytocous versus Monotocous Dairy Goats Using Suppressive Subtractive Hybridization

In this study, suppressive subtractive hybridization (SSH) was performed to screen differentially expressed genes in ovarian tissues between polytocous and monotocous goats. From the SSH cDNA library, we obtained 29 differentially expressed sequence tags (ESTs) that have high similarity with known genes in the public database, which were involved in signal transduction, transcriptional regulation, cellular molecular dynamics, cytoskeleton, metabolism and oxidation-reduction. In addition, one novel EST that has no similarity with known genes in the public database was obtained. Eight ESTs, TIMP1, NUCB1, OAZ1, CXXC5, CAPNS2, ATP5A1, Z and RPL5, were further examined for the reproducibility of the SSH data by the real-time quantitative PCR. The results confirmed an increased expression of respective mRNA in ovarian tissues of polytocous goats compared with those of monotocous goats. The study has identified several genes (known or unknown) that may have effect on follicular development, ovulation and egg activation in goats.

Identification and profiling of microRNAs in the ovaries of polytocous and monotocous goats during estrus

MicroRNAs (miRNAs) play critical roles in almost all ovarian biological processes, including folliculogenesis, ovulation, luteal development, and regression. The study identified known and novel miRNAs in the ovaries of polytocous and monotocous goats by combining Solexa sequencing with bioinformatics. In total, 862 known and 53 novel miRNAs were identified in the ovaries of polytocous and monotocous goats. A total of 771 miRNAs were co-expressed in both libraries. One hundred twenty miRNAs in the ovaries of polytocous goats and 24 miRNAs in the ovaries of monotocous goats were specifically expressed. In addition, 445 miRNAs were differentially expressed in the ovaries of polytocous and monotocous goats, of which 348 were upregulated, and 97 were downregulated in the ovaries of polytocous goats compared with the ovaries of monotocous goats (P values < 0.05 and |log2 (fold change)|> 1). The expression levels of 12 randomly selected miRNAs were analyzed by stem-loop real-time quantitative polymerase chain reaction, and the results demonstrated that the expression patterns were consistent with Solexa sequencing results. KEGG analysis showed that GnRH, transforming growth factor-beta, vascular endothelial growth factor, and mammalian target of rapamycin signaling pathways, oocyte meiosis and ovarian steroidogenesis participated in follicular development and ovulation. On the basis of miRNA-mRNA network analysis and luciferase reporter assays, the ggo-miR-4488-p3_1ss10CG, bta-miR-2892-p5_1ss8CG and hsa-miR-4532_L+1R-3 were closely related with prolific traits. The results will help to further understand the role of miRNAs in kidding rate regulation.

GRP78 expression and immunohistochemical localization in the female reproductive tract of mice

The 78-kDa glucose-regulated protein (GRP78) is an endoplasmic reticulum chaperone, with multiple functional roles in protein processing and provision of cellular protection. However, the physiological role of GRP78 in embryo development is not clear. Localization of GRP78 and expression of its mRNA in the reproductive organs throughout the estrous cycle in mice were investigated by immunohistochemistry and real-time polymerase chain reaction, respectively. Whereas there was intense staining for GRP78 in the oviduct at estrus, the ciliated cells of isthmus had better staining than those of infundibulum and ampulla at all phases of the cycle. Furthermore, GRP78 was located in the uterine luminal and glandular epithelial cells throughout the estrous cycle, particularly during the estrus phase. However, levels of GRP78 mRNA in the oviduct and uterus varied during the cycle, with peaks at estrus. In conclusion, GRP78 expression varied with the phase of the murine estrous cycle; this might be related to gamete transport, fertilization and early development of the zygote/embryo.

MiR-26a promoted endometrial epithelium cells (EECs) proliferation and induced stromal cells (ESCs) apoptosis via the PTEN-PI3K/AKT pathway in dairy goats†

Changes in endometrial cell morphology and function are absolutely necessary for successful embryo implantation. In this study, miR‐26a was widely expressed in dairy goats, and was found to be regulated by β‐estradiol (E2) and progesterone (P4) in endometrial epithelium cells (EECs) as well as stromal cells (ESCs). Furthermore, miR‐26a played a role in the regulation of cells proliferation and apoptosis by directly regulating PTEN and indirectly regulating the PI3K/AKT pathway in EECs but not in ESCs of dairy goats in vitro. In addition, miR‐26a regulated the expression of osteopontin (OPN), vascular endothelial growth factor (VEGF), Cyclooxygenase‐2 (COX‐2), and prolactin (PRL) in endometrial cells. Therefore, we could get a conclusion that miR‐26a had very complex and diverse functions in the endometrial cells during the development of endometrial receptivity in dairy goats. This study provided an efficient platform for studying the regulatory effect of miR‐26a on endometrial cells during the development of endometrial receptivity in dairy goats.