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).

It is well known that the production of transgenic bovine embryos is more difficult than the production of non-transgenic bovine embryos. We performed whether the quality of transgenic bovine embryos expressing the enhanced green fluorescent protein (EGFP) can be improved when cultured for 4 days from day 4 until day 8 after activation with epidermal growth factor (EGF), insulin-like growth factor (IGF), and flavonoid (F) supplements. The EGFP gene was introduced into bovine IVF embryos using microinjector. In experiment, transgenic bovine embryos were cultured in modified CR1aa medium containing 10% FBS at 38.8℃ in an incubator (5% CO2, 5% O2, and 90% N2) for 8 days and embryos were equally divided into four groups [non-treated group (control), 1 μM IGF+EGF (IE), 10 μM F and 1 μM IGF+EGF+10 μ M F (IEF)] at day 4 embryos. In the result, development rate of F treatment group (41.8%) was higher than that of control (33.3%), IE (23.9%) and IEF groups (28.0%). However, hatching rate was significantly high in IE (53.0%) and IEF (65.0%) groups than in control (42.9%) and F group (42.8%) (p<0.05). The EGFP expression rate was not different among all groups (30.0~33.3%) at blastocyst stage. In comparison of total cell number, IE group (145.2±10.4) was significantly higher than control group (101.4±14.3). Apoptotic index of IE group (1.9%) was the lowest compared with that of control (3.3%), F (3.5%) and IEF groups (4.6%). This result demonstrate that the combination of IGF, EGF and flavonoid can be helpful to improve the development potential and the quality of transgenic bovine embryos.

The α-Gal epitope (Galα1,3Galα1,4GlcNAc-R) is responsible for hyperacute rejection (HAR) during transgenic pig-to-non-human primate xenotransplantation. There are genes related to the expression of α-Gal epitope such as α1,3Galactosyltransferase gene (GT-/-) and the isoglobotrihexosylceramide synthase (iGb3s-/-). This study was performed to investigate the expression of α-Gal epitope in the skin derived from GT-/- transgenic pig. The skin (7/1000 inches) was obtained by dermatome (Zimmer® Electric Dermatome) from one month old of wildtype (WT) and GT-/- piglets, respectively. The skins were fixed, dehydrated, cleaned, and embedded. To analyze the expression of α-Gal epitope, the paraffin section of WT and GT-/- were stained with BS-IB4 lectin and isoglobotrihexosylceramide synthase antibody. There was a strong BS-IB4 lectin signal in the skin of WT, but not detected in GT-/-. However, the iGb3s positive signals were stained in the skin of both WT and GT-/-. Taken together, it can be postulated that the knocked out of GT gene may not enough to inhibit the expression of α-Gal epitope. Further studies are needed to evaluate the functions of the double knock out of GT and iGb3s on the expression of α-Gal epitope.

The α-Gal epitope (Galα1,3Galα1,4GlcNAc-R) is responsible for hyperacute rejection (HAR) during transgenic pig-to-non-human primate xenotransplantation. To overcome HAR after xenografts, it is essential for the inactivation of α1,3Galactosyltransferase (GT) gene by the homozygotic knocked out of GT-/- and the isoglobotrihexosylceramide synthase (iGb3s-/-). This study was performed to investigate the generation and characterization of the α1,3GT-MCP/-MCP+iGb3-/- transgenic cells. Ear fibroblast cells from the GT-MCP/-MCP pig were cultured and used to positive control. For iGb3s knock out, the Cas9-GFP-iGb3s vector was transfected into the GT-MCP/-MCP cells. The Cas9-GFP-iGb3s transfected cells were sorted and sequenced for the selection of GT-MCP/-MCP+ iGb3s-/- cells. Among the three sorted cell lines, one transgenic cell line was homozygously deleted 3 bases and 10 bases in each chromosome, respectively. To characterize an expression of α-Gal epitope, a wild type and the transgenic cells were measured by FACS Aria using BS-IB4 lectin antibody. The expression of α-Gal epitope in GT-MCP/-MCP cells (<0.01 %) were significantly down-regulated to the range of wild type (99.4 %) fibroblast cells (p<0.05). To analyze the function of iGb3s, α -Gal epitope expressions were measured for the GT-MCP/-MCP, GT-MCP/-MCP+iGb3s-/+, and GT-MCP/-MCP+iGb3s-/-. The range was 95.8%, 94.2%, and 75.8%, respectively. Interestingly, there was a negative range (16.2%) of α-Gal epitope -/- section in GT-MCP/-MCP+iGb3s-/-, compared to 2.74% of GT-MCP/-MCP+iGb3s-/+ and 1.4% of WT, respectively. Our results demonstrated that iGb3s-/-combined with GT-/- had a function to inhibit α-Gal epitope expression in pig cells. Further studies are needed to evaluate the functions of double gene knock out to minimize a HAR response after xenotransplantation.

돼지의 장기를 영장류에 이식할 때 단시간 내에 발생하는 초급성 면역거부반응 문제를 해결하기 위해 이를 제어할 수 있는 alpha1,3-galactosyltransferase knock out (Gal-T-/-) 돼지를 생산하였다. 그럼에도 불구하고 그 심장을 이식을 받은 영장류가 사망하는 것으로 보고되었으며, 그 원인은 non-Gal 항원-항체 반응에 의한 면역반응과 돼지와 영장류 간 분자, 생리적 차이에 의해 발생하는 급성 체액성 거부반응 때문이라고 알려져 있다. 본 연구는 어떤 인자와 기전에 의해 이식된 장기가 손상되고 사망하게 되는지 분자 수준에 서 알아보기 위하여, 영장류에 이식한 Gal-T-/- 돼지 심장에서 유전자의 발현 변화를 분 석하였다. 이를 위해 동일 부모에서 태어난 Gal-T-/- 돼지의 이식에 활용하지 않은 심장 을 대조군으로 하여 cynomolous 원숭이에 이식 후 9일째 채취한 심장으로부터 총 RNA 를 추출한 후 Sequencing을 통해 전 돼지 유전자의 발현수준을 비교하였다. 분석 결과, 이식된 심장에서 1292개의 유전자 발현이 유의적으로 증가하였고, 949개는 유의적으로 감 소하는 것으로 분석되었다. 이 중에서 심근 경색 등과 같이 심장이 손상되면 발현이 증가 하는 matricellular 단백질 유전자인 tenascin C(23.7배), Tsp-1(13.9배), -2(5.8배), -4(6.6 배), SPARC(3.6)의 발현이 증가한 것으로 분석되었다. 특히 혈관에서 혈액 응고를 촉진 시킨다고 알려진 Tsp-1의 발현이 유의하게 증가한다는 것을 quantitative RT-PCR 분석 으로 확인하였다. 또한 혈액응고의 중요한 조절 인자인 TF의 발현이 증가한 반면 억제 인자인 TFPI와 TBM의 발현은 변화가 없다는 것을 확인하였다. 이러한 결과는 이식 과 정 중에 가해진 생리적 또는 물리적 손상 및 원숭이 혈액의 재관류 자극에 의해 심장의 기능 마커 유전자가 지속적으로 발현되는 것으로 예측된다.

Using a partial D-loop sequence of mtDNA, a comprehensive molecular evolutionary analysis was performed of the maternal lineages of the Jeju native pigs(JNPs) that presented in Jeju Island. A total of 100 DNA sequences from Asian domestic pigs(ADP), European domestic pigs(EDP), Asian wild boars(AWB), European wild boars(EWB), and JNPs were used for the molecular evolutionary analyses including phylogeny and network analyses. The most fitted model for the phylogenetic analysis was determined using hierarchical likelihood-ratio tests conducted by MrModeltest implemented in the PAUP package. A consensus tree was established from 5,000,000 iterations using the MR BAYS program. Three recognizable JNP groups–one(JNPE) in the European cluster and two(JNPA1 and JNPA2) in the Asian cluster–were detected in the estimated phylogenetic tree and network. The maternal lineage of JNPE was the most adjacent to that of EWB and a clear haplogroup sharing an identical haplotype(hap16) among 15 individuals of JNPE and 2 individuals of EWB was detected.

축산농가에서 사육되는 주요 가축으로 한우, 젖소, 돼지, 가금류, 흑염소, 사슴, 말 등으로 이들 가축 들은 생산성을 높이기 위하여는 과학적인 번식관리를 통한 증식과 개량이 꾸준히 적용되어지고 있다. 농촌진흥청에서 축산농가에 제공되는 연구개발된 번식분야 실용화 기술들은 매년 보급되고 있으며 활 용도를 높이기 위하여 책자, DVD, 인터넷 등 매체를 통하여 보급되고 있다. 이와 같이 1993~2016년 동안 제공된 영농활용기술 중 번식분야를 중심으로 제공된 기술을 분석하여 향후 축산농가 번식기술 방향을 제시하고자 조사를 실시하였다. 1993~2016년 동안 번식분야 영농활용기술은 총 407건으로 축 종별로는 한우 170건, 젖소 94건, 돼지 97건, 가금류 18건, 흑염소 12건, 사슴 8건, 말 7건 등이었고, 번식 기능별로는 번식관리 167건, 인공수정 99건, 수정란이식 45건, 교배계획 31건, 가금번식 14건 등 순이었 다. 번식관리 분야는 전체 167건에서 호르몬 처리에 의한 번식력 향상 기술이 35건, 사료 사양관리 17, 비타민급여 번식효율 향상 9, 신체충실지수(BCS) 7건, 발정관찰 5건, 임신진단 4건 등 순이었다. 인공 수정 분야는 전체 99건에서 인공수정 일반기술이 42건, 정액제조 21건, 정액선택 16건, 정액보존 11건, 정액채취 6건 등 이었다. 수정란이식 분야는 전체 45건에서 호르몬처리에 의한 수정란이식 일반관리기 술 16건, 다배란유기 기술이 12건, 신체충실지수 적용기술이 4건, 수정란 성판별 기술 2건 등이었다. 가금류 번식분야는 14건에서 부화기술 5건, 종계관리 4건, 종란관리 3건, 인공수정 2건이었다.