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.

Effect of Dietary Selenomethionine Supplementation on Growth Performance, Tissue Se Concentration, and Blood Glutathione Peroxidase Activity in Kid Boer Goats.

We used 240 kid Boer goats that were divided into six groups. The control group was fed a basal diet containing 0.05 mg of selenium (Se)/kg dry matter (DM). Trial groups received the basal diet supplemented with 0.1, 0.2, 0.3, 0.4, or 0.5 mg Se/kg DM (using a commercial selenomethionine product). Trial groups showed an improvement in growth performance (P < 0.05) despite no change in average daily feed intakes (ADFIs) (P > 0.05) compared to the control group A, quadratic model showed a correlation between glutathione peroxidase activity level in whole blood and dietary Se concentration (R(2) = 0.883, P < 0.04). The best linear model showed that increasing concentrations of Se in the blood (R(2) = 0.968, P < 0.001) and muscle (R(2) = 0.942, P < 0.001) corresponded to increasing Se concentrations in feed. Accumulation of Se in different tissues and organs corresponded to increasing Se concentrations in the diet as well as to the total time goats spent feeding on supplemented diet. Kidney and muscle tissues showed the highest and lowest accumulation of Se, respectively. Thus, Se in goat meat can be increased by adding between 0.1 and 0.5 mg/kg of selenomethionine to the diet of goats.

Identification and gene expression analyses of natriuretic peptide system in the ovary of goat (Capra hircus).

Natriuretic peptides (NPs) are involved in maintaining cardiovascular and fluid homeostasis, regulating reproductive processes and bone growth, and other numerous functions. To better understand the role of NPs in goat (Capra hircus), in the present study, full-length cDNAs of goat Nppa (natriuretic peptide precursor A), Nppb (natriuretic peptide precursor B) and Nppc (natriuretic peptide precursor C), respectively encoding ANP, BNP and CNP, were cloned from adult goat heart and ovary. The putative prepropeptide ANP (prepro-ANP) and prepro-CNP share a high amino acid sequence identity with other species. Real-time PCR showed that Nppa, Nppb and Nppc were widely expressed in adult goat tissues. The mRNA expression of Nppa and Nppb in the heart was extremely higher compared with other tissues. Nppc mRNA expression in the lung and uterus was also higher than in other tissues. The expression of Nppa, Nppb and Nppc genes was examined at different ovarian follicle stages using RT-PCR. The mRNAs of Nppa and Nppb were detected in secondary follicles as well as in COCs (cumulus-oocyte-complexes) and granulosa cells of antral follicles. However, the mRNA expression of Nppc was observed throughout ovarian follicle development, and it was especially higher in granulosa cells of antral follicles. In vitro, stimulating goat granulosa cells with FSH led to an increase in the expression of Nppc by dose- and time-dependent manners and a rapid decline was induced by LH stimulation, but the expression of Nppa and Nppb did not change after FSH or LH treatment. These results suggest that Nppc is a gonadotropin-induced gene in granulosa cells of goat ovary and CNP may be involved in the regulation of ovarian follicle development and oocyte maturation.

Study on polymerization effect of polyembryony genes by SSCP marker and family trees in Chinese goats.

The aim of experiment was to analyze the polymerization effect of genotypes and genotype combinations of PRLR and LHß gene loci in Xinong Saanen goat by SSCP marker and family trees. The relationships of genotype combinations and litter size were compared in Xinong Saanen goat. The results indicate that there are genetic polymorphisms at the PRLR and LHß gene loci, and there are 4 positive genotypes (GG, CC, PP and LL) and 4 negative genotypes (HH, DD, QQ and MM) effects on litter size, respectively in Xinong Saanen goat. Compared with the other genotype combinations, the polymerization effect of GGCCPPLL markedly improved (P < 0.05). The polymerization effect value of CC genotype was higher than that of CD genotype by 14.12%, and MM genotype was higher than that of LM genotype by 3.80%, and PP genotype was higher than that of QQ genotype by 15.67%, and LL genotype was higher than that of LM genotype by 11.48%, and PQ genotype was higher than that of QQ genotype by 11.02%, and CD genotype was higher than that of DD genotype by 10.69%, and PQ genotype was higher than that of PP genotype by 6.09%. There was significantly polymerization effect in the course of reproduction from parental generation (F0) to F1 generation. However, there was significantly gene isolation effect in the course of reproduction from F1 generation to F2 generation. This result can be used to guide the goat breeding in polyembryony trait.

Development and application of a novel signal peptide probe vector with PGA as reporter in Bacillus subtilis WB700: twenty-four tat pathway signal peptides from Bacillus subtilis were monitored.

In this study, we have developed a novel, versatile signal peptide probe vector driven by promoter P43 in Bacillus subtilis WB700, using Penicillin G Acylase (PGA) as reporter. Twenty-four signal peptides considered belonging to twin-arginine translocation (Tat) pathway were cloned into the probe vector to direct the secretion expression of PGA, respectively. Through 6-nitro-3-phenylacetamidobenzoic acid (NIPAB) filter paper assay, four signal peptides (AmyX, AlbB, LipA, and YmzC) were chosen for further investigation. The extracellular production of PGA demonstrated that these recombinants mediated efficient secretion expression in B. subtilis WB700, in which the maximum activity reached 0.11, 0.21, 0.08, and 0.26 U/mL, respectively. Thus, we provided an efficient tool for easy detection of the signal peptides in B. subtilis, and demonstrated the efficiency of Tat pathway signal peptides via PGA secretion in B. subtilis WB700.

An optimal method of DNA silver staining in polyacrylamide gels.

A silver staining technique has widely been used to detect DNA fragments with high sensitivity on polyacrylamide gels. The conventional procedure of the silver staining is tedious, which takes about 40-60 min and needs five or six kinds of chemicals and four kinds of solutions. Although our previous improved method reduced several steps, it still needed six kinds of chemicals. The objective of this study was to improve further the existing procedures and develop an optimal method for DNA silver staining on polyacrylamide gels. The novel procedure could be completed with only four chemicals and two solutions within 20 min. The steps of ethanol, acetic acid, and nitric acid precession before silver impregnation have been eliminated and the minimal AgNO3 dose has been used in this up-to-date method. The polyacrylamide gel of the DNA silver staining displayed a golden yellow and transparent background with high sensitivity. The minimum 0.44 and 3.5 ng of DNA amount could be detected in denaturing and nondenaturing polyacrylamide gel, respectively. This result indicated that our optimal method can save time and cost, and still keep a high sensitivity for DNA staining in polyacrylamide gels.

[Establishment of a new method for early embryo culture in vitro].

A new method, nest culture method, was developed in this study. The culture effects of different methods for embryo culture in vitro were compared. The results showed that whether the suspension in phi35mm dish in nest culture method was covered with mineral oil or not, the developmental rates of embryos had no significant difference. Compared to the nest culture method, the developmental rates of embryos in Brinster's method were significant lower. However, all embryos cultured in the single dish in which the suspensions were not covered with mineral oil were blocked at 2-cell stage. The nest culture method is an effective method for early embryo culture in vitro.