Abstract
This study was taken to isolate transferrin fractions from the sera of tilapia(Oreochromis niloticus) by physico-chemical analyses such as the rivanol precipitation, iron-staining method, SDS-polyacrylamide gel electrophoresis and $^{59}FeCl_3$ autoradiography, and to calculate gene frequencies by using Hardy-Weinberg Law. The results obtained in this experiment were summarized as follow : 1. The transferrin fraction is composed of several components possessing relative lower electrophoretic mobilities and higher molecular sizes than the albumin components. 2. When different staining method was compared with transferrin in band, it was not found difference. 3. It was concluded that the optimun ratio of rivanol to serum was 2 : 1 and this ratio was used in all further fractionation. 4. The molecular weight of transferrin component was about 70,000 $\pm$ 2,000. 5. Tilapia transferrin fractionations were found to be polymorphic. 6. There transferrin variants(A, B and C) have been found in tilapia(Oreochromis niloticus) and Tf types were assumed to be controlled by three codominant alleles Tf A, Tf B and Tf C. Six different phenotypes can be theoretically expected Tf AA, Tf AB, Tf AC, Tf BB, Tf BC, and Tf CC. Only five types of these were observed and Tf CC types(homozygotes) was not found. 7. The frequencies of the three allele Tf A, Tf B and Tf C were 0.795, 0.15 and 0.055 respectively.
본 실험은 rivanol 침전법, iron-staining method, SDS-Polyacrylamide gel electrophoresis 그리고 $^{59}FeCl_3$ sutoradiography를 이용하여 tilapia(Oreochromis niloticus) 혈청으로부터 transferrin을 분리 추출하며, Hardy-Weinberg법칙을 이용하며 유전자 빈도와 유전자형 빈도 추정하기 위하여 시도하였다. 본 실험에서 얻어진 결과는 다음과 같다. 1. Tilapia의 transferrin은 albumin보다 상대적으로 느린 전기영동도와 높은 분자양의 크기를 가졌고, globulin 보다는 빠른 전기영동도와 낮은 분자양을 나타내었다. 2. 염색방법을 달리하여 transferrin의 band를 비교하였을 때, 별다른 차리를 발견하지 못했다. 3. Rivanol 대 혈청의 비율은 2 : 1이 가장 적합했고, 모든 분획에 이 비율을 이용하였다. 4. Transferrin의 분자양은 각 70,000$\pm$2,000을 나타내었다. 5. Transferrin의 종내 다형현상을 나타내었다. 6. 3개의 transferrin 변이체(A,B 그리고 C)가 발견되었고, Tf형은 3개의 공동 우성 대립유전자(Tf A, Tf B 그리고 Tf C)에 의해 조절되며, 6개의 가능한 표현형(Tf AA, Tf AB, Tf AC, Tf BC 그리고 Tf CC)중에서 5개의 표현형만이 발견되었고, Tf CC형은 발견되지 않았다. 7. 3개의 대립유전자 Tf A, Tf B 그리고 Tf C의 빈도는 각각 0.795, 0.15 그리고 0.055 이었다.