Using RT-PCR and glutathione level to study the effect of follicular fluid on in vitro maturation and gene expression of sheep oocytes

Differential proteomic analysis demonstrates follicle fluid participate immune reaction and protein translation in yak

Background

Ovarian follicle fluid (FF) as a microenvironment surrounding oocyte plays critical roles in physio-biochemical processes of follicle development and oocyte maturation. It is hypothesized that proteins in yak FF participate in the physio-biochemical pathways. The primary aims of this study were to find differentially expressed proteins (DEPs) between mature and immature FF, and to elucidating functions of the mature and immature FF in yak.

Results

The mature and immature FF samples were obtained from three healthy yaks that were nonpregnant, aged from four to five years, and free from any anatomical reproductive disorders. The FF samples were subjected to mass spectrometry with the isobaric tags for relative and absolute quantification (iTRAQ). The FF samples went through correlation analysis, principle component analysis, and expression pattern analysis based on quantification of the identified proteins. Four hundred sixty-three DEPs between mature and immature FF were identified. The DEPs between the mature and immature FF samples underwent gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and protein-protein interaction (PPI) analysis. The DEPs highly expressed in the mature FF mainly took parts in the complement and coagulation cascades, defense response, acute-phase response, response to other organism pathways to avoid invasion of exogenous microorganisms. The complement activation pathway contains eight DEPs, namely C2, C5, C6, C7, C9, C4BPA, CFH, and MBL2. The three DEPs, CATHL4, CHGA, and PGLYRP1, take parts in defense response pathway to prevent invasion of exogenetic microorganism. The coagulation cascades pathway involves many coagulation factors, such as F7, F13A1, FGA, FGB, FGG, KLKB1, KNG1, MASP1, SERPINA1, and SERPIND1. While the DEPs highly expressed in the immature FF participated in protein translation, peptide biosynthetic process, DNA conformation change, and DNA geometric change pathways to facilitate follicle development. The translation pathway contains many ribosomal proteins, such as RPL3, RPL5, RPS3, RPS6, and other translation factors, such as EIF3J, EIF4G2, ETF1, MOV10, and NARS. The DNA conformation change and DNA geometric change involve nine DEPs, DDX1, G3BP1, HMGB1, HMGB2, HMGB3, MCM3, MCM5, MCM6, and RUVBL2. Furthermore, the expressed levels of the main DEPs, C2 and SERPIND1, were confirmed by western blot.

Conclusions

The differential proteomics revealed the up-regulated DEPs in mature FF take parts in immunoreaction to prevent invasion of microorganisms and the up-regulated DEPs in immature FF participate in protein synthesis, which may improve our knowledge of the follicular microenvironment and its biological roles for reproductive processes in yak. The DEPs, C2 and SERPIND1, can be considered as protein markers for mature yak follicle.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03097-0.

In vitro production of small ruminant embryos: latest improvements and further research

This review presents the latest advances in and main obstacles to the application of invitro embryo production (IVEP) systems in small ruminants. This biotechnology is an extremely important tool for genetic improvement for livestock and is essential for the establishment of other biotechnologies, such as cloning and transgenesis. At present, the IVEP market is almost non-existent for small ruminants, in contrast with the trends observed in cattle. This is probably related to the lower added value of small ruminants, lower commercial demand and fewer qualified professionals interested in this area. Moreover, there are fewer research groups working on small ruminant IVEP than those working with cattle and pigs. The heterogeneity of oocytes collected from growing follicles in live females or from ovaries collected from abattoirs remains a challenge for IVEP dissemination in goats and sheep. Of note, although the logistics of oocyte collection from live small ruminant females are more complex than in the bovine, in general the IVEP outcomes, in terms of blastocyst production, are similar. We anticipate that after appropriate training and repeatable results, the commercial demand for small ruminant invitro -produced embryos may increase.

The in vitro development of cloned sheep embryos treated with Scriptaid and Trichostatin (A)

Although, it has been success in the generation of animal clones from somatic cells in various animal species, the information related to nuclear reprogramming of cloned embryos is found to be limited. This study aims to compares the effect of both Scriptaid (SCR) and Trichostatin (A) treatments in improving cloning efficiency, and embryos developmental rate of cloned sheep embryos in vitro. Three groups were formed, i.e., one SCR group, second TSA group, with both treatment concentrations of 5 nM, 50 nM, and 500 nM, respectively, and third were control group with 0 nM. Methods: Ovaries of slaughtered sheep were collected and oocytes were recovered from antral follicles using aspiration method and in vitro maturation of oocytes were done. Then zona dissecting with micropipettes and oocyte enucleation were carried out under the micromanipulator. Later nuclear transfer, cell fusion and activation were done via cell fusion machine. Finally the embryo cultured in incubating chamber at the CO2 incubator up to 9 days. The result: In general the results showed that when the concentration increases the cleavage rate increased. The cleavage rates of the SCNT embryos treated with SCR at different concentrations are closely related to cleavage rate of embryos treated with TSA at same concentration; such as 39.47% for 500 nM TSA, 38.09% for 500 nM SCR; 18.6% for 50 nM TSA, 19.17% for 50 nM SCR, and 22.64% for 5 nM TSA, 17.18% for 5 nM SCR. As for the control group, the cleavage rate of the SCNT embryos cleavage ratewere27.47%., 30% and 30.85% respectively for bothtreatments. While there is a significant difference in TSA treatments at an eight-cell stage at the concentration (5 and 50 nM TSA) compared to the all other cleavage cell stages of (500 nM TSA and control). Also their were a differences between (50 nM of TSA) compared to the (50 nM SCR). Also there were a significant differences between the 16 cell stage at the (500 nM TSA) compared to other treatment (5 nM, 50 nM TSA and control). Regarding the SCR there were a significant difference at 8 cell stage between (5 nM SCR), compared to the other treatment (50 nM, 500 nM SCR and control). Also there were a significant difference at 16 cell stage between (50 nM, and 500 nM SCR), compared to the other treatment (5 nM SCR and control). While in the development of the embryos reach to blastocyst stage the SCR and the control group show a higher rate, in compered to TSA that did not show any development to blastocyst stage. The total SCR treatment showed (3/41 = 7.31%), and the total control showed (4/89 = 4.49%) blastula stage. It concludes that SCR improve the final development blastula stage compared to the TSA treatments that did not improved embryos reach to final developmental blastula stages may be due to spices differences or to the toxicity of TSA, especially at higher concentrations.