Cloning of Porcine Pituitary Tumor Transforming Gene 1 and Its Expression in Porcine Oocytes and Embryos

Proteomic Exploration of Porcine Oocytes During Meiotic Maturation in vitro Using an Accurate TMT-Based Quantitative Approach

The dynamic changes in protein expression are well known to be required for oocyte meiotic maturation. Although proteomic analysis has been performed in porcine oocytes during in vitro maturation, there is still no full data because of the technical limitations at that time. Here, a novel tandem mass tag (TMT)-based quantitative approach was used to compare the proteomic profiles of porcine immature and in vitro mature oocytes. The results of our study showed that there were 763 proteins considered with significant difference−450 over-expressed and 313 under-expressed proteins. The GO and KEGG analyses revealed multiple regulatory mechanisms of oocyte nuclear and cytoplasmic maturation such as spindle and chromosome configurations, cytoskeletal reconstruction, epigenetic modifications, energy metabolism, signal transduction and others. In addition, 12 proteins identified with high-confidence peptide and related to oocyte maturation were quantified by a parallel reaction monitoring technique to validate the reliability of TMT results. In conclusion, we provided a detailed proteomics dataset to enrich the understanding of molecular characteristics underlying porcine oocyte maturation in vitro.

Single-Cell RNA-Seq Revealed the Gene Expression Pattern during the In Vitro Maturation of Donkey Oocytes

Donkeys are an important domesticated animal, providing labor, meat, milk, and medicinal materials for humans. However, the donkey population is continuously declining and even at risk of extinction. The application of modern animal production technology, such as oocyte in vitro maturation, is a promising method to improve the donkey population. In this study, we explore the gene expression patterns of donkey germinal vesicle (GV) and in vitro matured metaphase II (MII) oocytes using single cell RNA-seq of the candidate genes along with the regulatory mechanisms that affect donkey oocyte maturation. We identified a total of 24,164 oocyte genes of which 9073 were significant differentially expressed in the GV and MII oocytes. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that these genes were associated with the meiotic cell cycle, mitochondrion activity, and N-glycan biosynthesis, which might be the key genes and regulatory mechanisms affecting the maturation of donkey oocytes. Our study provides considerable understanding regarding the maturation of donkey oocytes and serves as a theoretical basis for improving the development of donkey oocytes, which could ultimately benefit the expansion of the donkey population and conservation of biodiversity and genetic resources.

The impact of transcription inhibition during in vitro maturation on the proteome of bovine oocytes†

Proper oocyte maturation is a prerequisite for successful reproduction and requires the resumption of meiosis to the metaphase II stage (MII). In bovine oocytes, nuclear maturation has been shown to occur in in vitro maturing cumulus-enclosed oocytes (COCs) in the absence of transcription, but their developmental capacity is reduced compared to transcriptionally competent COCs. To assess the impact of transcription during in vitro maturation of bovine COCs on the quantitative oocyte proteome, a holistic nano-LC-MS/MS analysis of germinal vesicle oocytes and MII oocytes matured with or without addition of the transcription inhibitor actinomycin D (ActD) was carried out. Analyzing eight biological replicates for each of the three groups, a total of 2018 proteins was identified. These could be clearly classified into proteins depending or not depending on transcription during oocyte maturation. Proteins whose abundance increased after maturation irrespective of transcription inhibition - and hence independent of transcription - were related to the cell cycle, reflecting the progression of meiosis, and to cellular component organization, which is crucial for cytoplasmic maturation. In contrast, transcription-dependent proteins were associated with cell-cell adhesion and translation. Since a high rate of protein synthesis in oocytes has been shown to correlate with their developmental competence, oocyte maturation in transcriptionally impaired COCs is apparently disturbed. Our experiments reveal that impaired transcription during in vitro maturation of COCs has a substantial effect on specific components of the oocyte proteome, and that transcription is required for specific classes of oocyte proteins predominantly involved in translation.

‘Cell cycle’ and ‘cell death’- related genes are differentially expressed during long – term in vitro real-time cultivation of porcine oviductal epithelial cells

Alterations in cells depend on their genetic material, its activation and translation of the products. The genes responsible for the cell cycle processes and apoptosis of porcine oviductal cells have been presented in our study. The processes occurring in the reproductive system of females are extremely complex and require in-depth knowledge. Thanks to in vitro studies on the fallopian tube epithelium cells, we can get closer to understanding the biochemical and morphological changes occurring in mammalian organisms. Our research was conducted on fallopian tubes obtained from commercially bred pigs and its aim was to assess the expression profile of genes responsible for the most important processes of cellular life. Cell cultures were carried out for 30 days, with the obtained cells subjected to molecular analysis. We have shown significant regulation of “cell death” and “cell cycle” genes, some of which are related to the reproductive system. The alterations in transcriptomic profile and mutual relations between the genes were analyzed and related to the literature findings. The knowledge gained could help in identifying new potential markers of the in vitro occurrence of processes described by the ontology groups of interest.

Running title: pig, oocytes, microarray assays, in vitro maturation (IVM)