Journal of Embryo Transfer (한국수정란이식학회지)

The Korean Society of Embryo Transfer (한국수정란이식학회)
권호 표지

Designing of the Statistical Models for Imprinting Patterns of Quantitative Traits Loci (QTL) in Swine

돼지에 있어서 양적 형질 유전자좌(QTL) 발현 특성 분석을 위한 통계적 검정 모형 설정

  • Published : 2004.12.01
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Abstract

Characterization of quantitative trait loci (QTL) was investigated in the experimental cross population between Berkshire and Yorkshire breed. A total of 512 F$_2$ offspring from 65 matting of F$_1$ parents were phenotyped the carcass traits included average daily gain (ADG), average backfat thickness (ABF), tenth rip backfat thickness (TRF), loin eye area (LEA), and last rip backfat thickness (LRF). All animals were genotyped for 125 markers across the genome. Marker linkage maps were derived and used in QTL analysis based on line cross least squares regression interval mapping. A decision tree to identify QTL with imprinting effects was developed based on tests against the Mendelian mode of QTL expression. To set the evidence of QTL presence, empirical significance thresholds were derived at chromosome-wise and genome-wise levels using specialized permutation strategies. Significance thresholds derived by the permutation test were validated in the data set based on simulation of a pedigree and data structure similar to the Berkshire-Yorkshire population. Genome scan revealed significant evidences for 13 imprinted QTLs affecting growth and body compositions of which nine were identified to be QTL with paternally expressed inheritance mode. Four of QTLs in the loin eye area (LEA), and tenth rip backfat thickness (TRF), a maternally expressed QTL were found on chromosome 10 and 12. These results support the useful statistical models to analyse the imprinting far the QTLs related carcass trait.

요크셔종과 버크셔종 교배 실험 집단을 활용하여 양적형질 유전자좌 (QTL)의 발현 특성 관련 유전 양식을 조사하였다. 총 512두의 F$_2$ 자손이 F$_1$간의 65교배 조합으로부터 생산되었으며 표현형 조사 기록은 일당증제량(ADG), 평균 등지방 두께(ABF), 10번째 등뼈 부위 등지방 두께(TRF) 및 등심단면적(LEA), 최후 척추부위 등지방 두께 (LRF)였다. 125종의 유전자 표지 (microsatellite)에 대한 3세대 개체별 유전자형이 분석되었으며 이들 정보를 통하여 최소자승 회귀 모형을 이용한 interval mapping 방법을 적용하였다. QTL의 유전양식 여부 검정에 대한 절차를 도식화하기 위해 귀무가설인 통상의 벤델리안 모형에 근거를 두고 수행하였다. 경험적 다중 검정 통계량에 대한 임계치는 단일 개개의 염색체 수준과 게놈 전반에 걸친 실험수준으로 유도하였으며, permutation에 의해 유도된 임계치의 유효성을 검증하기 위해 본 연구에 활용된 실험축 집단 구조와 유사한 simulation 집단 구조에 의해 산출된 결과들과 비교하여 유효성이 인정되었다. 본 연구에 활용된 실험축 집단구조와 Genome 전반에 걸친 QTL imprinting 여부를 조사한 결과 13종의 QTL 에 대한 imprinting이 확인되었으며 이들 중 9종의 QTL 유전 양식은 부계로부터 전달된 자손에게만 발현되는 것으로 추론되었다.

Keywords

References

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