Preparation and Property of Antibacterial Nucleus with the Combination of Nano-Silver and Antibiotics

To improve the yield and quality of pearls in freshwater pearl culture and the survival rates after nucleus implanting surgery, pearl farmers used artificial pearl nuclear transplantation techniques to raise pearls. To address the common problem of Staphylococcus aureus and Escherichia coli infection in oyster farming, a new prophylactic method by using compound antibiotics to prepare the medicine coated pearl nucleus was put forward based on existing research results of the nanosilver antibacterial nucleus. Single-factor experiment, multi-factor experiment, orthogonal experiment, SPSS analysis of variance was used to optimize the antibacterial formulation on the assumption that the contaminated probability of these two pathogenic bacteria was the same. The result showed that the optimal ratio of compound antibiotics was 0.0075g/ml of the flavomycin solution and 0.01g/mL of the terramycin solution; the inhibition zones diameter of both pathogenic bacteria was more than 2.6cm in vitro, which was higher than the nanosilver antibacterial nucleus of 0.9cm in vitro. Indicating that the addition of this compound antibiotic formula for the nanosilver antibacterial nucleus could reduce the usage of antibiotics under the premise of maintaining antibacterial effectiveness, and could preferably inhibit the pathogenic microorganisms in the postoperative infection period. This also indicates that compound antibiotics coated antibacterial nanosilver nucleus would be applied more widely.

3. Personalized pluripotent stem cells

‘Personalized pluripotent stem cells’ discusses cloning and its connection to stem cell biology. Somatic cell nuclear transplantation into oocytes can make personalized pluripotent stem cells as a perfect genetic match to a specific patient that provoke no immune rejection on grafting. Because this procedure involves generation of cells but no formation of an actual cloned individual, it has become known as human therapeutic cloning. Induced pluripotent stem cells (iPS cells) are made by introducing a few specific genes into normal cells. They are also a perfect genetic match to the individual donating the normal cells and because they are easy to make are now the preferred source.

Identification of Chromatin Accessibility During The Early Stage of Pig SCNT Embryo Reprogramming by ATAC-Seq

Background: Somatic cell nuclear transplantation (SCNT) can transform highly differentiated donor nuclei into pluripotent nuclei through the large-scale reprogramming of chromatin. The reprogramming of chromatin has been documented to take place in the first few hours after SCNT embryo activation. Thus, studies that characterize dynamic changes in chromatin during the first few hours after embryo activation could provide insight into the mechanism and significance of genome-wide reprogramming. However, few studies have examined the epigenetic remodeling of reconstructed embryos during the early stage of reprogramming.Results: We conducted ATAC-seq on 50 porcine SCNT-HMC embryos and 50 parthenogenetic activation (PA) embryos 10 h after activation. Along with pig embryonic fibroblast (PEF) ATAC-seq data, we found low levels of chromatin accessibility and gene transcription in SCNT and PA embryos. Moreover, PEF genes and the X chromosome became inaccessible during embryo reprogramming. GO enrichment analysis revealed that the molecular functions related to accessible chromatin in embryos primarily included transcriptional regulatory activity and SMAD binding. The differentially accessible chromatin sites between SCNT and PEF were primarily related to transcriptional activity and histone modification.Conclusions: Despite the tight chromatin structure during the early stage of embryo reprogramming, some accessible chromatin sites, which were primarily distributed in the intergenic region, were still detected. Dynamic changes in chromatin accessibility during reprogramming were primarily related to transcriptional activity and histone modification. Generally, this study provided new insight into the dynamics and importance of chromatin accessibility during the early stages of embryo reprogramming.

Mitochondrial Genetic Drift after Nuclear Transfer in Oocytes

Mitochondria are energy-producing intracellular organelles containing their own genetic material in the form of mitochondrial DNA (mtDNA), which codes for proteins and RNAs essential for mitochondrial function. Some mtDNA mutations can cause mitochondria-related diseases. Mitochondrial diseases are a heterogeneous group of inherited disorders with no cure, in which mutated mtDNA is passed from mothers to offspring via maternal egg cytoplasm. Mitochondrial replacement (MR) is a genome transfer technology in which mtDNA carrying disease-related mutations is replaced by presumably disease-free mtDNA. This therapy aims at preventing the transmission of known disease-causing mitochondria to the next generation. Here, a proof of concept for the specific removal or editing of mtDNA disease-related mutations by genome editing is introduced. Although the amount of mtDNA carryover introduced into human oocytes during nuclear transfer is low, the safety of mtDNA heteroplasmy remains a concern. This is particularly true regarding donor-recipient mtDNA mismatch (mtDNA–mtDNA), mtDNA-nuclear DNA (nDNA) mismatch caused by mixing recipient nDNA with donor mtDNA, and mtDNA replicative segregation. These conditions can lead to mtDNA genetic drift and reversion to the original genotype. In this review, we address the current state of knowledge regarding nuclear transplantation for preventing the inheritance of mitochondrial diseases.