Zona pellucida (ZP), a primarily representative coat of mammalian egg and embryo, has an extremely heterogeneous morphology during different developmental stages. The objective of the present study was to compare the morphological changes of the ZP surface of immature, in vitro and in vivo matured canine oocytes by using scanning electron microscopy (SEM). Canine ovaries were collected from local veterinary hospitals to recover immature oocytes. The ovaries were sliced and the released cumulus oocyte complexes (COCs) were washed with TL-HEPES. The selected COCs were randomly divided into two groups, first group was processed immediately at immature state and the second group was processed 72 h after in vitro maturation, and compared with in vivo derived oocytes. Oocytes were fixed, critical point dried and examined under SEM. The diameters of oocyte and outer holes of the ZP were measured on a total of 249 oocytes; the results were analyzed using One-way ANOVA. Our results showed that, the diameter of immature oocytes significantly differed (p < 0.05) from that of in vivo matured oocytes (79.60 ± 0.77 μm vs. 101.46 ± 1.07 μm, respectively). Similarly, a significant difference (p < 0.05) in the diameters between those of in vitro and in vivo matured oocytes were found (79.51 ± 2.36 μm vs. 101.46 ± 1.07 μm, respectively). Moreover, the diameters of the outer holes of the ZP were significantly (p < 0.05) larger in in vivo matured (1.48 ± 0.42 μm) than in vitro matured for 72 and immature oocytes (1.10 ± 0.16 and 0.43 ± 0.12 μm, respectively). Taken together, these data indicates that the ZP surface is related to oocyte maturity in canine.

Up-to-date artificial insemination (AI) using frozen sperm consider as the most widely using technology for improvement of Korean Native Cow (Hanwoo) embryo production. However, it is time consuming, required at least 15~20 years to make more than 6 generations, and their offspring number is limited. To overcome such limitations, superovulation and in vitro fertilization have been developed. For superovulation, the number of produced embryos are not enough for commercialization and donor cows need rest period. This led to use of slaughterhouse ovary for in vitro fertilization, but it is impossible to repeat the collection from the same individual and it only can improve the genetic merits of offspring for one generation. Production of embryos using Ovum Pick-Up (OPU) technique, where oocytes can be repeatedly collected from living elite donor, might overcome these limitations. In this study, we investigated the possibility of using OPU technique from donors at different age and different session periods for mass-embryo-production. Oocytes were collected from 26 donor cows twice per week, 3 - 4 months per year, between 2013 and 2016. Results showed that, the average number of embryo produced in first year used donor was significantly higher than that in second year used donor (3.89 ± 2.85 vs 3.29 ± 2.70), however, there was no significant difference between third year used donor (3.51 ± 3.32) and other groups. Taken together, our data showed that repeated using of donor up to three years is possible for in vitro embryo mass-production. Moreover, OPU can be used as suitable embryo producing technique for livestock breed improvement.

The aim of this study was to investigate the role of Src homology 2-containing phosphotyrosine phosphatase SHP2 in intricate signaling network invoked by oocyte to achieve cytoplasmic maturation and also blastocyst development. Activation of SHP2 regulates multicellular differentiation, proliferation and survival through numerous signal pathways. The most prominent pathway is RAS/PI3K and p-AKT signaling cascade, as a result mitogenic effect become enhanced. Oocytes were cultured in cisplatin an anticancer drug, but selective activator of SHP2 and our grouping were SOF medium alone, SOF + EGF, SOF + CISPLATIN 0.3 μM, and SOF + EGF + CISPLATIN 0.3 μM. We evaluated that EGF neutralizes the apoptotic effect of cisplatin as well as maintain the high expression of SHP2, as a result blastocyst development become boosted up. We also found that inhibition of SHP2 with its specific inhibitor PHPS1 5 μM decreases the blastocyst development and neutralizes growth factors effect. The developmental ability and quality of bovine embryos were determined by assessing their cell number, gene expression, immunofluorescence, and immunoblot. The differences in embryo development between experimental groups were analyzed by one-way ANOVA. Our results show that SHP2 have significant effect on MAP kinase pathways which expand the cumulus cells during oocyte maturation and blastocyst development as compare to inhibition of SHP2 with PHPS1. SHP2 not only transduce the signaling of epidermal growth factor but it also has a role in signal transduction of FGF and IGF. The expression of ERK, PI3K/p-AKT and mTOR was increased with EGF, but with the treatment of SHP2 inhibitor the expression of these genes become drop done. So we can conclude from these results that SHP2 is important for oocyte maturation as well as for blastocyst development.

Bovine somatic cell nuclear transfer (bSCNT) embryos can develop to the blastocyst stage at a rate similar to that of embryos produced by in vitro fertilization (IVF). However, the efficiency of somatic cell cloning has remained low, and applications have been limited, irrespective of the nuclear donor species or cell types. One possible explanation is that the reprogramming factors of each oocyte is insufficient or not properly adapted for the receipt of a somatic cell nucleus, because it is naturally prepared only for the receipt of a gamete. Here, we would like to introduce the aggregation method (agSCNT), a new experimental system that enables and increase oocyte volume and examined its subsequent development. Judgement by the blastocyst formation rate or total cell number was significantly higher in the agSCNT group than that in the SCNT group, and was very similar to that in the control IVF group. Moreover, the cleavage formation rate in the agSCNT group (61.5 ± 1.3) was higher than that in the SCNT group (39.7 ± 2.1), while still less than that in the IVF group (75.4 ± 1.3). We also analyzed the epigenetic modifications in bovine IVF, agSCNT, and untreated SCNT embryos. In conclusion, the present study demonstrated that agSCNT improves the in vitro developmental competence and quality of cloned embryos, as evidenced by increased total cell numbers (TC).

The production of feline induced pluripotent stem cells (iPSCs) can solve the problems that are related with existing unstable supply and demand of eggs as well as ethical aspects about embryonic stem cell at the same time. On the basis of excellent proliferation, it is to facilitate the researches about human disease like FIV and Allergen at the level of cells, not experimental animals. But, a lot of advanced researches are lean too much towards on the transduction using DNA type virus that have the risk of tumorigenesis during reprogramming and on the mLIF-dependent culture condition for the production of feline iPSCs. This being so, this study shows the reprogramming results using Sendai virus vector that is RNA type virus and have no the footprint after transduction. In addition, the feline iPSCs were stably cultured in bFGF-dependent culture condition during the reprogramming step and culture step. In conclusion, we found the bFGF-dependent culture condition in feline iPSCs and suggested the approach using Sendai virus vector as an alternative for reprogramming without concern about tumorigenesis. These methods can be universally applicable to not only the researches about reconstruction and conservation of feline species, but also to a lot of deep studies related with iPSCs or LIF, bFGF to find new approaches.