Background: The successful production of superior or transgenic offspring from in vitro produced embryos in cattle relies heavily on the quality of blastocyst stage embryos. In order to enhance the developmental competency of these embryos, a novel culture method was devised. Methods: This study utilized stem cell culture medium (SCM) from hESCs as a supplement within the culture medium for bovine in vitro produced embryos. To gauge the efficacy of this approach, in vitro fertilized embryos were subjected to culture in CR1aa medium enriched with one of three supplements: 0.3% BSA, 10% FBS, or 10% SCM. Results: The blastocyst development and hatching rates of one-cell zygotes cultured in CR1aa medium supplemented with SCM (23.9% and 10.2%) surpassed those cultured in CR1aa medium supplemented with BSA (9.3% and 0.0%) or FBS (3.1% and 0.0%) (p < 0.05). Furthermore, post-zygotic gene activation, cleaved embryos cultured in CR1aa medium supplemented with SCM (57.8% and 34.5%) exhibited notably higher rates (p < 0.05) compared to those cultured with BSA (12.9% and 0.0%) or FBS (45.7% and 22.5%) supplementation. Furthermore, the microinjection of SCM into the cytoplasm or pronucleus of fertilized zygotes resulted in elevated blastocyst development and hatching rates, particularly when the microinjected embryos were subsequently cultured in CR1aa medium supplemented with SCM from the 8-cell embryo stage onwards (p < 0.05), in contrast to those cultured with FBS supplementation. Conclusions: In conclusion, this study conclusively demonstrated that the incorporation of SCM into the culture medium significantly enhances the developmental progress of preimplantation embryos.

본 연구는 붉바리 어미의 사육환경에 따른 난질의 변화를 난의 생화학적 분석을 통하여 난질 에 영향을 미칠 수 있는 요소를 구명하기 위하여 수행하였다. 그 결과 육상수조에서 사육하는 것보다 해상가두리에서 사육할 때 부상률, 수정률, 난 발생 생존율 및 부화율이 우수하였다. 그 리고 해상가두리에서 생산한 수정란의 유리아미노산의 함량이 높았다. 즉, 해상가두리에서 사 육관리할 때 난질이 우수한 수정란을 생산할 수 있고, 난질이 우수할수록 유리아미노산의 함 량이 높았다.

The experimental fish transplanted from China in 2015 was used after seedling production and cultivated. Breeding management for experiment was carried out from October 2020 to February 2021. Also, it succeeded in inducing artificial maturation three to four months earlier than wild broodstock and secured good quality fertilized eggs. The average size of fertilized eggs was 1.22 mm, at 20℃ Blastodisc (15 minutes post-fertilization), 2 cell (50 minutes), 4 cell (1 hours), 8 cell (2 hours), 16 cell (2 hours and 30 minutes), 32 cell (2 hours and 50 minutes), morula (3 hours), blastula (8 hours), gastrula (15 hours), skull formation (20 hours), organ formation (30 hours) and hatching yolk larvae stage (35 hours). The total length of the just hatched larvae were 2.50 ± 2 mm, and then gain growth of 42.5 mm by 60 days, reaching 45 ± 5 mm.

Natural environmental resources are considered a prospective source of microorganisms capable of producing biocatalysts with great potential in industrial areas. Arable soil fertilized with peat moss is a habitat for various microorganisms. The present research focused on the isolation and identification of hydrolase-producing bacteria that thrive at a broad temperature range. In this study, a total of 33 strains were isolated from arable soil fertilized with peat moss (Silla Garden in Busan, South Korea). The isolated bacteria were mesophiles and thermophiles with a wide temperature range. Taxonomic identification showed that the isolated strains belonged to 2 phyla, 5 families, 10 genera, and 24 species. Subsequently, the isolated strains were screened for hydrolase (amylase, lipase, and protease) activity. All isolates possessed activity of at least one enzyme and six bacterial isolates produced combined extracellular enzymes. Diversity of soil bacteria species in the present study suggest the potential of soil bacteria in the various industrial applications.

미토콘드리아는 세포질 칼슘 항상성 및 ATP 생산에 중요한 역할을 하는 세포 소기관으로 이러한 미토콘드리아의 기능은 성숙과 수정 그리고 배 발달에 매우 중요한 역할을 한다. 미토콘드리아 칼슘 축적은 기능장애를 일으킨다. 그러나 돼지 체외성숙란 및 수정란에서 미토콘드리아 칼슘 변화의 관련성에 관한 연구는 보고된 적이 없다. 본 연구의 목적은 미토콘드리아 칼슘 지시자로 알려진 Rhod-2 염색을 이용하여 성숙란 및 수정란에서 미토콘드리아 칼슘 축적의 변화를 확인하였다. 형태학적 모습의 기준을 통해 난구세포의 세포층과 세포질의 균질도를 바탕으로 G1과 G2로 나누어서 체외성숙을 진행하였다. 이후 두 그룹에서 핵 성숙율을 비교하였을 때, G2가 G1에 비해 낮게 나타났다(p<0.001). 돼지 체외성숙란 및 수정란에서 평균적인 Rhod-2 spot 의 수는 G1보다 G2에서 더 많이 나타났다(6시간째 체외수정란: p<0.05). 다음으로 Rhod-2 spot 수에 따른 난모세포의 비율을 확인하기 위해 Rhod-2 spot 의 수를 4개의 군(n<10, 10≤n<20, 20≤n<30, 그리고 30≤n)으로 나누어 해당 난모세포의 비율을 확인하였다. 체외성숙란 및 체외수정란 모두 G1이 G2에 비해 10개 미만(n<10)인 Rhod-2 spot 의 수를 가지는 난모세포가 많았으며, 체외수정란에서는 유의적으로 높았다(p<0.05). 마지막으로 체외성숙란 및 수정란에서 Rhod-2 intensity 값을 측정하여 두 그룹을 비교하였을 때, G2가 G1에 비해 유의적으로 높은 것을 확인 할 수 있었다(성숙란; p<0.001 그리고 수정란; p<0.05). 본 연구의 결과를 토대로 돼지에서 미성숙 난포란의 형태학적인 품질은 체외성숙 및 체외수정 과정 동안 미토콘드리아 내 칼슘 축적과 관련이 있음을 확인하였다.

Polo-like kinase 1 (Plk1) has been known to be a critical element in cell division including centrosome maturation, cytokinesis and spindle formation in somatic, cancer, and mammalian embryonic cells. In particular, Plk1 is highly expressed in cancer cells. Plk1 inhibitors, such as BI2536, have been widely used to prevent cell division as an anticancer drug. In this study, the fertilized murine oocytes were treated with BI2536 for 30 min after recovery from the oviduct to investigate the effect of down-regulation of Plk1 in the in vivo-fertilized murine embryos. Then, the localization and expression of Plk1 was observed by immunofluorescence staining. The sperm which had entered into the oocyte cytoplasm did not form male pronuclei in BI2536-treated oocytes. The BI2536-treated oocytes showed significantly lower expression of Plk1 than non-treated control group. In addition, alpha-tubulin and Plk1 gathered around sperm head in non-treated oocytes, while BI2536-treated oocytes did not show this phenomenon. The present study demonstrates that the Plk1 inhibitor, BI2536, hinders fertilization by inhibiting the formation of murine male pronucleus

Mitochondrion is an organelle for regulating calcium (Ca2+) homeostasis. Mitochondrial Ca2+ plays important roles on oocyte maturation, fertilization and embryonic development for ATP production. Low quality oocytes have mitochondrial dysfunction, which lead to overloaded Ca2+ in mitochondria. Recently, Rhod-2 is well known as a mitochondrial derived Ca2+ indicator. However, the changes of Rhod-2 in matured or fertilized porcine oocytes have not been reported. Therefore, the aim of study was to identify the effects of mitochondrial Ca2+ using Rhod-2 on quality assessment of matured oocyte and zygotes in pigs. Thus, we classified two groups (group 1: G1, compact COCs and group 2: G2, uncompact COCs) according to differences of cumulus cells amount and cytoplasm morphology in germinal vesicle (GV) stage of porcine COCs. Therefore, we investigated number of Rhod-2 spots in matured and fertilized oocytes from G1 and G2 groups. The Rhod-2 spot numbers were separated into four parts; n<10, 10≤ n < 20, 20 ≤ n < 30, and 30 < n. The Rhod-2 spots number of G2 group had greater than G1 group in part of 20 ≤ n. Additionally, we investigate mean number of Rhod-2 spots from G1 and G2 groups in matured and fertilized oocytes. As a result, we confirmed that average number of Rhod-2 spots in G2 group increased than that of G2 group. Finally, we also measured the Rhod-2 intensity in matured and fertilized oocytes of G1 and G2 groups. Interestingly, the Rhod-2 intensity in G2 group was higher than that of G1 group. (oocyte: p < 0.001 and fertilized oocyte: p < 0.05). These results demonstrated that changes in Rhod-2 spots and intensity were increased in low quality of matured and fertilized oocytes. Therefore, our results suggest that the differences in mitochondrial calcium level are associated with morphological quality of porcine COCs.

It has been claimed that artificial insemination (AI) of cows with frozen-thawed semen treated with commercially produced kits, Wholemom (in favour of female gender) increases the birth chance of calves with desired sex ratio by approximately 85% without decrease of pregnancy rates. Hence, this study was conducted to investigate the efficacy of wholemom kits as combined with frozen-thawed bovine semen during in vitro fertilization on the in vitro fertilization and developmental efficiency and sex ratios such as some reproductive parameters in bovine. For this, 1,737 oocytes were in vitro fertilized and developed. Agglutination effects on bovine after treatment of Wholemom kit were observed by time passage and dose respectively. To determine sex of embryos, Bovine embryo Y-specific gene primers(ConEY) and Bovine specific universal primer(ConBV) were used as multiple PCR method. Fertilization rate of wholemom-treated group was significantly lower than its of control group[66.9% (1,156/1,737) in Wholemom-treated group; 75.0% (610/813) in control group]. However, developmental rate after fertilization of both wholemom-treated and control groups were not significantly different [26.1% (404/1,156) in Wholemom-treated group; 27.4% (224/610) in control group]. Sex ratio of in vitro fertilized embryo with frozen-thawed semen treated with wholemom kit was determined by multi PCR. Female ratio in wholemom-treated group [85.4% (173/201)] was significantly higher than its of control group [47.2% (66/141)]. In conclusion, wholemom treatments of semen used in the in vitro fertilization and development of bovine oocytes provided increase in female ratio with decrease of fertilization rate.

To increase the productivity of in vitro development, the antioxidants have been used for culture system of bovine oocytes and embryos. However, comparative studies on these molecules are rare and direct beneficial effects on blastocyst production cannot be discriminated for best results. The study was conducted to determine the influence of N-acetyl-L-cysteine (NAC), N-acetyl-L-cysteine amide (NACA), glutathione (GSH) and cysteamime (CYS) on maturation competence of COCs from GV to MII stage and productivity of blastocyst formation during in vitro fertilization and culture. There was no difference among maturation rates of oocytes to metaphase II with polar body with antioxidants for any of the treatment groups (p>0.05). However, the significant improvement on the rate of blastocysts (32.3±5.0%) was found in 0.1 mM CYS treatment than 0.3 mM NAC, 0.2 mM NACA or 0.5mM GSH (p<0.05). The addition of NAC (18.8±3.7%) or NACA (21.2±3.9%) did not improve development competence to morula and blastocysts than control (24.4±4.1%) and GSH (26.5±5.0%) (p>0.05). Our study showed that medium supplementation with CYS during IVM and IVC improved the rate of bovine embryo development but not with NAC, NACA and GSH addition.

Lysophosphatidic acid (LPA) is an important signaling molecule which mediates many different cellular responses. The purpose of this study was to investigate the effect of in vitro culture (IVC) medium supplemented with LPA on the preimplantation embryonic development of porcine embryos derived from in vitro fertilization (IVF). Embryos derived from IVF were cultured in PZM-3 medium supplemented with 30 μM LPA on Day 1 to Day 7, Day 1 to Day 3 (early stage), or Day 4 to Day 7 (late stage), or without LPA. Moreover, the messenger RNA (mRNA) expression of obtaining blastocysts from each group were analyzed. Data were analyzed by ANOVA followed by Duncan using SPSS (Statistical Package for Social Science) mean ± SEM. There was a significantly higher cleavage rate in Day 1 to Day 7 than control (71.25% and 57.46%, respectively) and significantly higher total cell number of blastocysts in Day 1 to Day 3 and Day 4 to Day 7 than control (56.07,56.53 and 45.19, respectively). The results also showed that the mRNA expression level of PCNA, Bcl-2 and Bax in Day 1 to Day 7 group blastocysts were significantly higher than control and the expression level of Bax in Day 1 to Day 3 was also significantly higher than control. Moreover, it also showed that Bcl-2/Bax mRNA ratio in D1-3 group was significantly lower than control but D4-7 and D1-7 groups were comparable to control group. In conclusion, our results suggest that treatment with 30 μM LPA during IVC improves the porcine early embryo cleavage and the blastocyst total cell number after IVF and regulating the mRNA expression of blastocysts during blastocyst formation.

Post-ejaculation of sperms into the female reproductive tract, acquisition of sperm capacitation is an essential step in the fertilization process. Accordingly, during in-vitro fertilization, the successful fertilization requires necessarily induction of capacitation in the retrieved sperms. To date, many candidate substances have been considered as capacitation inducers. However, there were no reports about the comparison of efficiency inducing sperm capacitation among diverse capacitation inducers. Therefore, we tried to determine an inducer showing the best capacitation performance in mouse sperms by comparing the preimplantation development of in-vitro-fertilized embryos using sperms experiencing capacitation by a variety of capacitation inducers. For these, calcium, progesterone, bovine serum albumin (BSA), heparin, lysophosphaticylcholine (Lyso-PC) were used as candidate capacitation inducers. Optimized concentration of each inducer were determined by accessing ratio of sperms experiencing acrosome reaction using coomassie G-250 blue staining. Subsequently, in vitro fertilization was performed using sperms incubated in each optimized concentration inducer. The ratio of fertilized oocytes was observed. As the results, Calcium at 2.7 mM and 0.3% (w/v) BSA showed the highest fertilization rates compared to 15 μM progesterone, 50 mM heparin, and 100 μM Lyso-PC. From these results, we found that 2.7 mM calcium and 0.3% (w/v) BSA were the most effective sperm capacitation inducers of mouse sperm for in vitro fertilization. From these results, we could identify that, among diverse sperm capacitation inducers, 2.7mM calcium and 0.3% (w/v) BSA were the most effective inducers for in vitro fertilization.

Many pronuclear stage eggs were used to generate transgenic mice (Tg) by microinjection. In this study, we used in vitro fertilized mouse eggs, followed by ultrarapid freezing to establish a simple procedure for production of Tg mice. We produced in vitro fertilized mouse eggs and cryopreserved them by ultrarapid freezing method. A total of 139 cryopreserved-thawed pronuclear eggs, of which 101 (72.6%) were survived following microinjection of chicken b-actin promoter-driven firefly improved luciferase cDNA (β-act/luc+) and were transferred into 5 recipients. All recipients became pregnant and gave birth to a total of 15 (14.8%) pups. As a control, same DNA construction (β- act/luc+) was also injected into 450 in vitro fertilized eggs, of which 338 (75.1%) were survived and then were transferred into 14 recipients. Eleven (78%) mice became pregnant and littered a total of 54 (19.1%) pups. Southern blotting analysis of Tg mice indicated that one (1/15, 6.6%) and three (3/54, 5.5%) transgenic mice were production from cryopreserved and in vitro fertilized eggs, respectively. All Tg mice produced from both eggs showed the expression of improved luciferase gene. These results indicated that efficiency of produced of Tg mice from cryopreserved eggs was comparable to that from in vitro fertilized eggs. Furthermore, it is suggested that microinjection of transgene into in vitro fertilized eggs cryopreserved by ultrarapid freezing is an easy and conveniently method for production of Tg mice.

Antioxidants, as reactive oxygen species scavengers, are one of the beneficial additives in serum-free defined culture medium. In this study, three separate experiments were performed to determine the effects of 3-hyroxyflavone added to the culture medium on the developmental competence of follicular bovine oocytes during in vitro maturation (IVM) and/or in vitro culture (IVC). The rate of blastocyst developed from oocytes cultured in IVM medium with 3 hyroxyflavone was significantly higher than that from control oocytes (39.0% vs. 26.3%, p<0.001), respectively. However, oocytes cultured in the medium with addition of 3-hyroxyflavone only at IVC period did not show significance in the blastocyst development when compared with control. When 3-hyroxyflavone was added to both IVM and IVC media, the rate of blastocyst formation was even significantly lower (21.1%) than control (26.5%; p<0.05). The present findings suggested that antioxidative activity of 3-hydroxyflavone added to only IVM medium beneficially affected the developmental competence of follicular bovine

돼지 수정란의 체외 생산 효율성 향상을 위해서는 배발생율과 더불어 고품질의 배를 조기에 선별해야 한다. 체외 배 발생율에 대한 보고는 많지만, 고품질의 배를 선별할 수 있는 기술에 대한 연구는 거의 없었다. 본 연구에서는 돼지 난포란 유래 수정란의 체외배양에 있어서 배반포로의 배 발달과 생존에 미치는 Vitamin K1(vit K1) 첨가 농도, 시기 및 시간의 효과를 검토하였다. 1.0 μM, 3.0 μM 및 6.0 μM vit K1을 배양 1일째 24시간 첨가한 결과, 배반포 발달율이 시험군이 14.5 ± 4.3, 0.0 및 0.0%로써 대조군의 35.5 ± 3.2%에 비하여 유의하게 낮았고(p<0.05), 배반포의 생존율도 대조군이 31.8 ± 2.6%로써 시험군의 22.2 ± 2.9, 0.0 및 0.0%에 비하여 유의하게 높았다(p<0.05). 상기 첨가 농도에서 첨가 시간을 달리한 결과, 1.0 μM 농도에서 6시간 처리군의 배반포 발달율과 생존율이 각각 26.5 ± 2.9% 및 47.2 ± 2.8%로써 가장 높았고 특히, 12시간 처리군보다 유의하게 높았다(p<0.05). 3.0 μM 농도에서는 대조군의 배발달율이 36.4 ± 3.1%로 가장 높았으나, 생존율은 3.0시간 첨가군이 41.7 ± 3.2%로 대조군에 비하여 유의하게 높았다(p<0.05). 6.0 μM 농도에서도 배발달율은 대조군(32.0 ± 2.8%), 생존율은 0.5시간 첨가군(42.9 ± 1.8%)이 가장 높았다. 각각의 vit K1 첨가 농도와 시간을 기준으로 서로 다른 배양 시기에 첨가한 결과, 1.0 μM 6시간 첨가군에서는 배반포 발달율은 배양 4일째 첨가군, 생존율은 배양 2일째 첨가군이 가장 높았다. 한편, 3.0 μM 3.0시간 및 6.0 μM 0.5시간 첨가군에서는 배양 4일째 첨가군의 배반포 발달율(59.5 ± 4.1% 및 50.0 ± 3.6%)과 생존율(72.7 ± 5.4% 및 79.2 ± 4.0%)이 대조군과 다른 시험군에 비하여 유의하게 높았다(p<0.05). 한편, vit K1 첨가에 따른 배반포의 세포 수를 조사한 결과, 첨가군(1.0 μM 6시간 배양 2일째, 3.0 μM 3.0시간 배양 4일째 및 6.0 μM 0.5시간 배양 6일째)이 53.4 ± 5.8, 49.4 ± 3.8 및 51.5 ± 4.5개로써 대조군의 40.2 ± 2.3개에 비하여 유의하게 많았다(p<0.05). 그러나 사멸세포 수는 시험군이 3.2 ± 0.9∼3.7 ± 2.1개로써 대조군의 4.2 ± 1.2개보다 적었으나, 유의차는 없었다. 세포 사멸 유도 유전자인 Bax mRNA 발현은 처리군과 대조군은 비슷하였으나, 세포 사멸 억제 유전자인 Bcl-xL mRNA 발현은 처리군이 대조군보다 높았고 특히, 6.0 μM 0.5시간 배양 4일째 첨가군이 가장 높았다. 이상의 결과로부터 돼지 미성숙 난포란 유래 수정란의 체외 배양에 vit K1의 첨가는 배반포의 생존율과 세포수 증가에 효과적이었다. 그 이유에 대해서는 아직 많은 부분이 밝혀져야 되겠지만, 고품질의 배반포 조기 선발에는 활용이 가능할 것으로 생각된다.

The present study was performed to investigate the effect of Hh-Ag1.5, a small-molecule chemical agonist of SMOothened receptor, on the in vitro maturation and development of in vitro fertilized (IVF) embryos in pigs. Oocytes or fertilized embryos were cultured in a maturation or embryo culture medium supplemented with 0 (control), 25, 50 or 100 nM of Hh-Ag1.5, respectively. Although the maturation rate were not different among treatment groups, the blastocyst formation rate in the group treated with 25 nM Hh-Ag1.5 was significantly increased compared to other groups (P<0.05). While the highest dose of Hh-Ag1.5 (100 nM) did negatively affect to the embryo development and cell number in blastocysts compared to other groups (P<0.05), the apoptotic cell index in blastocysts was significantly lower in 25 and 50 nM groups than in control and 100 nM groups (P<0.05). The mRNA expression of the proapoptotic gene Bax and the ratio of Bax/Bcl-XL decreased in among treatment groups compared to control (P<0.05). The embryo quality related genes, Tert and Zfp42, were significantly decreased in 50 and 100 nM groups compared with control and 25 nM groups (P<0.05). In conclusion, the addition of 25 nM Hh-Ag1.5 to in vitro maturation and culture medium can enhance the developmental potential as well as quality of IVF embryos in pig.

This study was designed to evaluate the effect of L-cysteine on sperm characteristics and oocyte cleavage in vitro in Korean native cattle. For this study, the freezing of diluted semen were added with Triladyl containing 20% eggyolk and/or 0, 5, 10 and 20 mM L-cysteine before cryopreservation. The viability in frozen-thawed sperm were estimated by SYBR14/PI double stain, acrosome damage with FITC-PNA, mitochondria intact with Rhodamin123 and hydrogen peroxide(H2O2) level with carboxy-DCFDA by flow-cytometry. The developmental capacity was also assessed with cleavage rates in oocytes fertilized in vitro by frozen-thawed sperm. In results, the sperm viability was significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). In addition, acrosome damage was significantly decreased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). The mitochondria intact was also significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). On the other hand, the cleavage rates were significantly increased in 0 mM, 5 mM and 10 mM groups than 20 mM concentration of L-cysteine (p<0.05). The oocyte degeneration of oocytes were significantly decreased in 0 mM, 5 mM and 10 mM groups than in 20 mM L-cysteine group (P<0.05). However, there are no significantly differences among the L-cysteine treatment groups. We suggest that concentration of 10 mM L-cysteine have beneficial impact for sperm cryopreserved in Korean native cattle. This result also could be recommended for artificial insemination program if supported by an improvement in the fertility results and required further study.

본 연구는 돼지의 난포란을 체외성숙하여 세포질내정자주입(ICSI)에 의해 생산된 체외수 정란의 체외발달율을 평가하기 위하여 실시하였다. 세포질내정자주입에 의한 체외수정란의 발달율은 서로 다른 보존상태의 정자인 신선정자, 액상정자 및 동결-융해된 정자를 이용하 더라도 수정율과 배발달율에는 영향을 미치지 않는 것으로 나타났다. 세포질내정자주입 후 난자의 전기적 활성화를 처리한 실험군이 활성화를 처리하지 않은 실험군에 비해 수정율과 배반포기배로의 발달율에 있어서는 높은 경향을 나타내었으나, 체외수정 실험군 및 전기적 활성화를 처리한 실험군과 전기적 활성화를 처리하지 않은 실험군간 배반포기배의 할구수는 유의적인 차이를 나타내지 않았다. 또한 각각의 실험군에서 얻은 배반포기배의 염색체를 분 석한 결과, 정상 이배체 염색체상의 비율에 있어서도 유의성을 나타내지 않았다.