C23 gene regulates the nucleolin structure and biosynthesis of ribosomes in bovine intraspecific and interspecific somatic cell nuclear transfer embryos

Proteomic Analysis and Reprogramming Potential of the Porcine Intra-Ooplasmic Nanovesicles

Oocytes contain reprogramming machinery that can transform somatic cells into totipotent cells. In this study, we aimed to isolate and characterize nanovesicles from mature porcine oocytes and described them for the first time as "intra-ooplasmic vesicles (IOVs)". Isolated IOVs had an average diameter of 186.3 ± 10.8 nm. Proteomic analysis revealed 467 peptide reads, with the top 20 proteins related to reprogramming, antioxidative defense, cytoskeleton, heat shock proteins, and metabolism. Protein-protein interaction and gene ontology analysis indicated that these proteins were involved in various biological pathways, including protein folding, metabolism, and cellular responses to stress. Supplementing cultured fibroblasts with IOVs resulted in the expression of the pluripotency marker OCT4 and the early trophoblastic marker CDX2 and increased expression of the corresponding mRNAs together with increasing KLF4 and SALL4 expression. IOV treatment of fibroblasts for 14 consecutive days resulted in changes in cell morphology, with increased expression of ZEB2 and YBX3 as markers for epithelial-to-mesenchymal transition (EMT). These results provide a rationale for further characterization of IOVs, investigation of potential reprogramming capabilities for EMT, and the generation of induced pluripotent or oligopotent stem cells.

Low Expression of Mitofusin 1 Gene Leads to Mitochondrial Dysfunction and Embryonic Genome Activation Failure in Ovine-Bovine Inter-Species Cloned Embryos

Inter-species somatic cell nuclear transfer (iSCNT) is significant in the study of biological problems such as embryonic genome activation and the mitochondrial function of embryos. Here, we used iSCNT as a model to determine whether abnormal embryo genome activation was caused by mitochondrial dysfunction. First, we found the ovine-bovine iSCNT embryos were developmentally blocked at the 8-cell stage. The reactive oxygen species level, mitochondrial membrane potential, and ATP level in ovine-bovine cloned embryos were significantly different from both bovine-bovine and IVF 8-cell stage embryos. RNA sequencing and q-PCR analysis revealed that mitochondrial transport, mitochondrial translational initiation, mitochondrial large ribosomal subunit, and mitochondrial outer membrane genes were abnormally expressed in the ovine-bovine embryos, and the mitochondrial outer membrane and mitochondrial ribosome large subunit genes, mitochondrial fusion gene 1, and ATPase Na+/K+ transporting subunit beta 3 gene were expressed at lower levels in the ovine-bovine cloned embryos. Furthermore, we found that overexpression and knockdown of Mfn1 significantly affected mitochondrial fusion and subsequent biological functions such as production of ATP, mitochondrial membrane potential, reactive oxygen species and gene expressions in cloned embryos. These findings enhance our understanding of the mechanism by which the Mfn1 gene regulates embryonic development and embryonic genome activation events.

The role of passage numbers of donor cells in the development of Arabian Oryx – Cow interspecific somatic cell nuclear transfer embryos

The cloning between different animals known as interspecific somatic cell nuclear transfer (iSCNT) was carried out for endangered species. The iSCNT has been characterized by a poor success rate due to several factors that influence the formation of the SCNT in various cytoplasms. The cell cycle of the transferred somatic cell, the passage number of the cultured somatic cell, the mitochondria oocytes, and their capabilities are among these factors. This study investigates the role of the passage number of the Arabian Oryx somatic cell culture when transplanted to an enucleated domestic cow oocyte and embryo development in vitro. The fibroblast somatic cell of the Arabian Oryx was cultured for several passage lanes (3–13). The optimal passage cell number was found to be 10–13 Oryx cell lines that progressed to various cell stages up to the blastula stage. There was some variation between the different passage numbers of the oryx cell line. The 3–9 cell line did not show a good developmental stage. These could be attributed to several factors that control the iSCNT as stated by several investigators. More investigation is needed to clarify the role of factors that affect the success rate for the iSCNT.