Linkage Disequilibrium and Gene Expression Analyses of IGF2 Gene in Korean Native Pigs

재래돼지를 이용한 IGF2 유전자의 연관불균형과 유전자발현양상에 대한 분석

  • Li, Song-Lan (College of Agriculture, Life and Environment Sciences, Chungbuk National University) ;
  • Li, Xiaoping (College of Agriculture, Life and Environment Sciences, Chungbuk National University) ;
  • Choi, Bong-Hwan (Animal Genomics and Bioinformatics Division, National Livestock Research Institute, RDA) ;
  • Lee, Cheol-Koo (Collelge of Life Sciences & Biotechnology, Korea University) ;
  • Cho, Byung-Wook (Department of Animal Science, Pusan National University) ;
  • Kim, Jong-Joo (School of Biotechnology, Yeungnam University) ;
  • Kim, Kwan-Suk (College of Agriculture, Life and Environment Sciences, Chungbuk National University)
  • 이송란 (충북대학교 농업생명환경대학 응용생명환경학부 축산학과) ;
  • 이소평 (충북대학교 농업생명환경대학 응용생명환경학부 축산학과) ;
  • 최봉환 (농촌진흥청 농촌진흥청 국립축산과학원) ;
  • 이철구 (고려대학교 생명과학대학 생명공학부) ;
  • 조병욱 (부산대학교 생명자원과학부) ;
  • 김종주 (영남대학교 생명공학부) ;
  • 김관석 (충북대학교 농업생명환경대학 응용생명환경학부 축산학과)
  • Received : 2008.10.14
  • Accepted : 2009.02.11
  • Published : 2009.02.01


Insulin-like growth factor 2 (IGF2) is the first identified imprinted gene, which is paternally expressed in multiple mammalian species. A paternally expressed QTL for muscle growth and backfat thickness (BFT) has previously been identified near the IGF2 locus on the distal tip of pig chromosome 2 (SSC2p). Therefore the IGF2 gene is considered an economically important candidate gene for pig industry. Herein, this study explored genetic variation of IGF2 for in3-G3072A, in7-G162C and a new SNP in intron7 (C1589T) in Korean native pig (KNP) and commercial pig breeds, and detected their linkage disequilibrium within these breeds. Furthermore we investigated the effect of in3-G3072A on IGF2 gene expression in post-natal muscle and backfat tissues. The real-time quantitative PCR results showed that animals inherited allele G from a KNP sire had significant higher IGF2 gene expression in backfat tissue than those inherited allele A from a Yorkshire sire, however opposite situation in muscle. These results demonstrated the allele 3072G is associated with a higher IGF2 gene expression in fat tissues, but low gene expression in muscle tissues when compared with the 3072A allele. These results suggest that KNP with lower muscle mass and higher fat deposition might be associated with a higher frequency of the 3072G allele, and selecting KNP based on IGF2 genotypes could result in an economic benefit to KNP producers.

IGF2 유전자는 최초로 연구된 각인 유전자이고 대부분 포유동물의 부계로부터 유전되는 각인 유전자이다. 근육성장과 지방축적에 연관된 경제 형질좌위가 2번 염색체에 위치하여 있다고 보고되었는데, IGF2-in3-G3072A가 원인 유전자변이라고 밝혀졌다. 본 연구는 IGF2 유전자의 Intron7번의 세 개의 SNP (IGF2-in7-G162C, IGF2-in7-C179G, IGF2-in7-G186T)는 IGF2-in3-G3072A와 품종 별 연관불균형으로 완전 연쇄되어 있는 것을 보고 하였다. Real-time quantitative PCR 실험 결과에서 부모세대가 부계가 IGF2-in3-3072A를 가진 요크셔품종 수퇘지가 IGF2-in3-3072G를 가진 한국재래 암퇘지와 교배하여 생산한 자손(Y그룹)과 IGF2-in3-3072G 유전자형의 한국재래품종 수퇘지와 IGF2-in3-3072A를 가진 요크셔 암퇘지와 교배하여 생산된 자손(K그룹)에서 보다 등지방 조직에서의 IGF2 유전자 발현양이 낮았다. 하지만 근육조직에서는 요크셔품종의 유전자형이 IGF2-in3-3072A를 부계로 하고 IGF2-in3-3072G를 한국재래돼지품종모계로 할 때 IGF2 유전자 발현양이 높은 결과를 보였다. 이러한 연구에서 IGF2 유전자의 근육과 지방조직에서의 발현양은 부계의 유전자형에 의해 결정되며, 한국재래돼지의 높은 체지방 축적과 낮은 성장률에 관련된 특성이 IGF2 유전자 유전자형에 의해 영향을 받는다는 유전적인 근거를 제공함으로써 한국재래돼지를 상업적으로 이용하는데 있어서 IGF2 유전자를 이용할 수 있는 분자유전학적 근거를 제시하였다.


Grant : DNA 마커 도움선발을 이용한 한국재래돼지 개량과 상업적 비육흑돼지 계통조성

Supported by : 농촌진흥청


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