오래전부터 산업곤충으로서 이용되어온 누에는 최근 바이오 신소재 생산을 위한 생체공장으로써 주목받고 있다. 소재생산을 위해서는 주 로 형질전환 기술을 이용하게 되며, 이는 배아가 있는 알 속으로 목적 유전자를 삽입하는 마이크로인젝션(microinjection) 방식으로 이루어진다. 마이크로인젝션을 위해서는 알을 고정하는 과정이 필수적이며 시간 소모 및 피로도가 높은 작업이다. 따라서 본 연구에서는 시간 소모 및 피로도 개선을 통하여 형질전환 효율을 높이고자 3D 프린팅을 이용하여 알의 정렬 및 고정에 도움을 줄 수 있는 알 배열판(egg liner) 및 접착제 줄눈판 (glue drawer)을 3DCADian 프로그램을 이용하여 모델링하고, Fusion 360를 이용하여 3차원 도면을 제작 후 프린팅하여 제작하였다. 제작된 두 도구를 이용하여 슬라이드 글라스에 알을 고정하고, 소요된 시간을 분석한 결과 도구를 사용하지 않았을 때에 비하여 2가지 도구를 이용했을 때 작업시간이 약18.6% 감소하였으며, 연구자의 작업 편의성을 향상시키고 마이크로인젝션을 위한 현미경 및 로봇 팔(manipulator) 조작을 유 리하게 하였다. 따라서 알의 배열 수 또는 조작 편의성을 개선할 수 있는 추가적인 연구 및 개량이 이루어진다면, 알 배열판 및 접착제 줄눈판이 누 에 형질전환 효율성 개선 및 다른 산업 곤충의 형질전환 연구에도 이용될 수 있을 것으로 판단된다.

CRISPR/Cas9-induced knock-out/-in can be occurred at specific locus in the genome by non-homologous end joining (NHEJ) or homology directed repair (HDR). Here, we demonstrate the targeted insertion into the specific loci of embryo fertilized by semen from transgenic cattle via CRISPR/Cas9 system. Recently, we published on the efficient generation of transgenic cattle using the DNA transposon system (Yum et al. Sci Rep. 2016 Jun 21;6:27185). In the study, eight transgenic cattle were born following transposon-mediated gene delivery system (Sleeping Beauty and Piggybac transposon system) via microinjection. In the analysis of their genome stability using next-generation sequencing, there was no significant difference in the number of genetic variants between transgenic and non-transgenic cattle. All the transgenic cattle have grown up to date (the oldest age: 33 months old, the youngest age: 15 months old) without any health issue. One of transgenic male cattle expressing GFP reached puberty and semen was collected. Over 200 frozen semen straws were produced and some were used for in vitro fertilization (IVF). On seven days after IVF, expression of GFP was observed at blastocyst stage and was seen in 80% of the embryos. Another application is to edit the GFP locus of the transgenic cattle because long-term and ubiquitous expression of transgene didn’t affect their health. In one cell stage embryos produced using GFP frozen-thawed semen, microinjection of sgRNA for GFP, Cas9, together with donor DNA that included RFP and homology arms to link the double-strand break of sgRNA target site into fertilized eggs resulted in expression of RFP. This indicated that the GFP locus of transgenic cattle shows potential candidates for stable insertion of the functional transgene. Knock-out/-in for editing GFP locus using CRISPR-Cas9 might be a valuable approach for the next generation of transgenic models by microinjection. In conclusion, we demonstrated P-112 that transgenic cattle via transposon system are healthy to date and germ-line competence was confirmed. The GFP locus will be used as the potential target site for future gene engineering via genome-editing technology. Finally, all those animals could be a valuable agricultural and veterinary science resource for studying the effects of gene manipulation on biomedical research and medicine. This work was supported by BK21 PLUS Program for Creative Veterinary Science and Seoul Milk Coop (SNU 550-20160004).

Transcription activator like effector nucleases (TALENs) are artificial restriction enzymes generated by fusing a TALE DNA binding domain to a DNA cleavage domain which remove and introduce specific genes to produce transgenic animals. To investigate the efficient laboratory techniques for the injection of TALEN mRNA, pEGFP-N1 commercial plasmid were microinjected into porcine parthenogenetic and in vitro fertilization (IVF). In Experiment 1, to investigate injection time, compared 4 different time durations (2 hr, 4 hrs, 6 hrs & 8 hrs) after post activation of parthenogenetic embryos and after 6 hrs of co-incubation with sperms in IVF embryos. There were significant difference (P<0.05) in development to the blastocysts (4.4, 8.9, 3.9, 0.6%), GFP expression in blastocysts (1.3, 5.7, 2.3, 0.0%) which injected after post activation of 4 hrs compared with other 3 groups. IVF embryos after 2 hrs and 4 hrs injected were expressed GFP significantly higher than rest of two groups (P<0.05). In Experiment 2, compared development of 2 different concentrations (20 ng/μl and 50 ng/μl) of EGFP injection. There were significant difference (P<0.05) between two treatments which has higher cleavage (58.8 vs 41.9%), blastocysts development rate (13.0 vs 11.1%) and GFP expressed blastocysts (5.7 vs 0.0%) in 20 ng/μl than the 50 ng/μl in parthenogenetic embryos. In IVF embryos, only 20 ng/μl injected embryos were expressed GFP (4.2%) after 7 days of incubation and 77.3 vs 64.7% of cleavage, 26.4 vs 23.5% development to blastocysts. In Experiment 3, three different volumes (5, 10 and 20 pl) were microinjected into porcine embryos to determine the most appropriate volume. Out of 3 groups, significantly higher development rates of cleavage (68.3, 58.0, 29.3%), blastocysts (11.7, 12.7, 0.5%) and GFP expressed blastocysts (2.9, 7.8, 0.0%) were shown in the 10 pl group (P<0.05). In conclusion, these results imply that 20 ng/μl concentration, 10 pl of volume and injection at 4 hrs after post activation for parthenogenetic and 2∼4 hrs after IVF, 20 ng/μl concentration and 10 pl volume for IVF embryos were more effective microinjection conditions.

This study was conducted to investigate the efficacy of vitrification procedure for the cryopreservation of porcine oocytes and the utilization of vitrified oocytes as recipient cytoplasts for somatic cell nuclear transfer (NT), and observed that porcine oocytes are evaluated by pronuclear formation, and parthenogenetic development. Single fetal donor cells were deposited into the perivitelline space of vitrified enucleation oocytes, followed by electrical fusion and activation. NT embryos were cultured in NCSU-23 medium supplemented with 5% FBS, at in 5% and air. 1. When the developmental rates of the oocytes after being culture for hours vitrified with EDS and ETS were 42.0%, 38.0%, respectively. This results were lower than the control group(62.2%). 2. When the developmental rates of the oocytes after being culture for hours vitrified-thawed with sucrose and glucose, 5% PVP, NCSU-23 supplemented with 10% FBS were 33.3%, 25.9%, respectively. This results were lower than the control group(55.6%). 3. The fusion and development to the blastocyst stage between the NT embryos constructed with the vitrified and non-vitrified oocytes were significant differences. Developmental rate of oocytes and NT embryos constructed with the vitrified or non-vitrified oocytes were , respectively.

Embryonic germ (EG) cells are undifferentiated stem cells isolated from cultured primordial germ cells (PGC). These cells share many characteristics with embryonic stem cells including morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of differentiation both in vitro and in vivo have been established. Since EG cells can be cultured indefinitely in an undifferentiated state, whereas somatic cells in primary culture are often unstable and have limited lifespan, EG cells may provide inexhaustible source of karyoplasts in nuclear transfer (NT). In this study the efficiencies of NT using porcine EG and fetal fibroblast cells were compared. Two different techniques were used to perform NT. With conventional NT procedure (Roslin method) involving fusion of donor cells with enucleated oocytes, the rates of development to the blastocyst stage in EG and somatic cell NT were 16.8% (59/351) and 14.5% (98/677), respectively. In piezo-driven microinjection (Honolulu method) of donor nuclei into enucleated oocytes, the rates of blastocyst formation in EG and somatic cell NT were 11.9% (15/126) and 9.4% (9/96), respectively. Regardless of NT methods used in this study, EG cell NT gave rise to comparable rate of blastocyst development to somatic cell NT. Overall, EG cells can be used as karyoplast donor in NT procedure, and embryos can be produced by EG cell NT that may be used as an alternative to conventional somatic cell NT.

본 연구는 돼지 난포란의 동결보존 후 생존성과 난자의 활성화 처리에 따른 체외발생율과 이를 이용한 핵 이식배의 체외발생율을 조사하였다. 활성화 처리된 배는 FBS가 첨가된 NCSU 23 배양액으로 , 와 air의 조건으로 배양하였다. 1. 난포란을 EDS와 PVP로 동결 후 FBS가 첨가된 NCSU 23 배양액으로 시간 배양했을 때 체외발생율은 로서 대조군인 비동결 난포란의 체외발생율 에 비해 낮았다. 2. Ethanol과 cyclojexamide로 처

본 연구는 한우 체외수정란에 외래 유전자를 미세현미 주입한 후 체외 배발달을 조사하였다. DNA 미세주입은 체외수정 18~20시간 후에 DNA를 미세주입하였으며 체외 배발달율은 7일간 배양 후 조사하였다. 미세현미 주입 후 난할율은 36.3%로 대조구의 난할율 66.4% 보다 유의적으로 낮았으며(p<0.05) DNA가 주입된 수정란 중 상실배와 배반포배까지 발달율은 각각 5.6%와 1.9%로 대조구의 20.5%와 12.8%에 비하여 유의적으로 낮게 나타