Effect of DNA and Histone Methyl Transferase Inhibitors on Outcomes of Buffalo–Bovine Interspecies Somatic Cell Nuclear Transfer

The acetyltransferase BmCBP changes the acetylation modification of BmSP3 and affects its protein expression in silkworm, Bombyx mori

BACKGROUND

Protein acetylation is an important post-translational modification (PTM) that widely exists in organisms. As a reversible PTM, acetylation modification can regulate the function of proteins with high efficiency. In the previous study, the acetylation sites of silkworm proteins were identified on a large scale by nano-HPLC/MS/MS (nanoscale high performance liquid chromatography-tandem secondary mass spectrometry), and a total of 11 acetylation sites were discovered on Bombyx mori nutrient-storage protein SP3 (BmSP3). The purpose of this study was to investigate the effect of acetylation level on BmSP3.

METHODS AND RESULTS

In this study, the acetylation of BmSP3 was further verified by immunoprecipitation (IP) and Western blotting. Then, it was confirmed that acetylation could up-regulate the expression of BmSP3 by improving its protein stability in BmN cells. Co-IP and RNAi experiments showed acetyltransferase BmCBP could bind to BmSP3 and catalyze its acetylation modification, then regulate the expression of BmSP3. Furthermore, the knock-down of BmCBP could improve the ubiquitination level of BmSP3. Both acetylation and ubiquitination occur on the side chain of lysine residues, therefore, we speculated that the acetylation of BmSP3 catalyzed by BmCBP could competitively inhibit its ubiquitination modification and improve its protein stability by inhibiting ubiquitin-mediated proteasome degradation pathway, and thereby increase the expression and intracellular accumulation.

CONCLUSIONS

BmCBP catalyzes the acetylation of BmSP3 and may improve the stability of BmSP3 by competitive ubiquitination. This conclusion provides a new functional basis for the extensive involvement of acetylation in the regulation of nutrient storage and utilization in silkworm, Bombyx mori.

Melatonin accelerates the developmental competence and telomere elongation in ovine SCNT embryos

SCNT embryos suffer from poor developmental competence (both in vitro and in vivo) due to various defects such as oxidative stress, incomplete epigenetic reprogramming, and flaws in telomere rejuvenation. It is very promising to ameliorate all these defects in SCNT embryos by supplementing the culture medium with a single compound. It has been demonstrated that melatonin, as a multitasking molecule, can improve the development of SCNT embryos, but its function during ovine SCNT embryos is unclear. We observed that supplementation of embryonic culture medium with 10 nM melatonin for 7 days accelerated the rate of blastocyst formation in ovine SCNT embryos. In addition, the quality of blastocysts increased in the melatonin-treated group compared with the SCNT control groups in terms of ICM, TE, total cell number, and mRNA expression of NANOG. Mechanistic studies in this study revealed that the melatonin-treated group had significantly lower ROS level, apoptotic cell ratio, and mRNA expression of CASPASE-3 and BAX/BCL2 ratio. In addition, melatonin promotes mitochondrial membrane potential and autophagy status (higher number of LC3B dots). Our results indicate that melatonin decreased the global level of 5mC and increased the level of H3K9ac in the treated blastocyst group compared with the blastocysts in the control group. More importantly, we demonstrated for the first time that melatonin treatment promoted telomere elongation in ovine SCNT embryos. This result offers the possibility of better development of ovine SCNT embryos after implantation. We concluded that melatonin can accelerate the reprogramming of telomere length in sheep SCNT embryos, in addition to its various beneficial effects such as increasing antioxidant capacity, reducing DNA damage, and improving the quality of derived blastocysts, all of which led to a higher in vitro development rate.

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.

Current status of assisted reproductive technologies in buffaloes

Buffaloes are raised by small farm holders primarily as source of draft power owing to its resistance to hot climate, disease, and stress conditions. Over the years, transformation of these animals from draft to dairy was deliberately carried out through genetic improvement program leading to the development of buffalo-based enterprises. Buffalo production is now getting more attention and interest from buffalo raisers due to its socioeconomic impact as well as its contribution to propelling the livestock industry in many developing countries. Reproduction of buffaloes, however, is confronted with huge challenge and concern as being generally less efficient to reproduce compared with cattle due to both intrinsic and extrinsic factors such as poor estrus manifestation, silent heat, marked seasonal infertility, postpartum anestrus, long calving interval, delayed puberty, inherently low number of primordial follicles in their ovaries, high incidence of atresia, and apoptosis. Assisted reproductive technologies (ARTs) are major interventions for the efficient utilization of follicle reserve in buffaloes. The present review focuses on estrus and ovulation synchronization for fixed time artificial insemination, in vitro embryo production, intracytoplasmic sperm injection, cryopreservation of oocytes and embryos, somatic cell nuclear transfer, the factors affecting utilization in various ARTs, and future perspectives in buffaloes.

Comparison of pregnancy rates with transfer of in vivo produced embryos derived using multiple ovulation and embryo transfer (MOET) with in vitro produced embryos by somatic cell nuclear transfer (SCNT) in the dromedary camel (Camelus dromedaries)

In the present study, there was comparison of pregnancy rates with transfer of in vivo-produced embryos using multiple ovulation and embryo transfer (MOET) with in vitro-produced embryos by somatic cell nuclear transfer (SCNT) in dromedary camels. In vivo-produced embryos were collected from donors after super-stimulation of follicular development on day 7 after ovulation, while in vitro-derived embryos were produced using SCNT from in vivo-matured oocytes collected from camels after follicular development super-stimulation. As a result of estrous synchronization, all recipient camels for both groups were 1 day earlier in stage of estrous cycle than developmental status of embryos at the time of transfer. The animals into which embryos were transferred were monitored at 7-day intervals after embryo transfer for signs of pregnancy based on response to presence of a male and there was ultrasonic confirmation on days 35 and 60 subsequent to day of estrus in recipient animals. A greater proportion of recipients (P <  0.05) were considered pregnant based on response to male presence when there was transfer of MOET-(76.8 ± 3.2) compared with SCNT- (26.4 ± 2.4) derived embryos on day 14. There was no difference in pregnancy losses in subsequent weeks until day 60 between groups. There were also no differences in calving rates of females in which MOET- (91.7%) and SCNT- (93.3%) derived embryos were transferred. These results indicate pregnancies at day 60 with SCNT-derived embryos are sustained for the remainder of gestation periods similar to when there was transfer of MOET-derived embryos in dromedary camels.

The N-space Episenome unifies cellular information space-time within cognition-based evolution

Self-referential cellular homeostasis is maintained by the measured assessment of both internal status and external conditions based within an integrated cellular information field. This cellular field attachment to biologic information space-time coordinates environmental inputs by connecting the cellular senome, as the sum of the sensory experiences of the cell, with its genome and epigenome. In multicellular organisms, individual cellular information fields aggregate into a collective information architectural matrix, termed a N-space Episenome, that enables mutualized organism-wide information management. It is hypothesized that biological organization represents a dual heritable system constituted by both its biological materiality and a conjoining N-space Episenome. It is further proposed that morphogenesis derives from reciprocations between these inter-related facets to yield coordinated multicellular growth and development. The N-space Episenome is conceived as a whole cell informational projection that is heritable, transferable via cell division and essential for the synchronous integration of the diverse self-referential cells that constitute holobionts.

Effect of supplemetation of Zebularine and Scriptaid on efficiency of in vitro developmental competence of ovine somatic cell nuclear transferred embryos

Somatic cell nuclear transfer (SCNT) technology has been applied in the construction of disease model, production of transgenic animals, therapeutic cloning, and other fields. However, the cloning efficiency remains limited. In our study, to improve SCNT efficiency, brilliant cresyl blue (BCB) staining were chosen to select recipient oocytes. In addition, DNA methyltransferase inhibitor Zebularine (5 nmol/L) and histone deacetylase inhibitor Scriptaid (0.2 μmol/L) were jointly used to treat sheep donor cumulus cells and reconstructed embryo. Moreover, the expression levels of embryonic development-related genes (OCT4, SOX2, H19, IGF2 and Dnmt1) of reconstructed embryo were also detected. Using BCB + oocytes as recipient cell, donor cumulus cells and reconstructed embryos were treated with 5 nmol/L Zebularine and 0.2 μmol/L Scriptaid, the blastocyst rate in Zeb + SCR-SCNT group (28.25%) was significantly higher than SCNT (21.16%) (p < 0.05). Furthermore, results showed that expression levels of OCT4, SOX2, H19, IGF2 and Dnmt1 genes in Zeb + SCR-SCNT embryos were more similar to IVF embryos. Our study proved that 5 nmol/L Zebularine and 0.2 μmol/L Scriptaid treating with sheep donor cumulus cells and reconstructed embryos improved SCNT blastocyst rate and relieve the abnormal expression of embryonic developmental related genes.