Hypoxia adaptation and hemoglobin mutation in Tibetan chick embryo
Tibetan chick lives at high altitudes between 2600 and 4200 m with a high hatchability and low land breeds survive rarely with a hatchability of 3.0% under hypoxia of simulated 4200 m. Under hypoxia of whole 21 d, the hatchability of Tibetan chick and Recessive White Feather broiler differed with a greatest disparity from day 4 to 11 and also significantly in other stages except from day 1 to 3. Hypoxia in each stage did not reduce significantly survival rate of this stage except hatchability. These two results indicated that the hypoxia in the early stage had an adverse effect on the later stage. All exons encoding chick hemoglobins were sequenced to analyze gene polymorphism. The functional mutation Met-32(B13)-Leu, related with hypoxia, was found in αD globin chain and the mutation frequency increased with increased altitude. In addition, under hypoxic conditions, the population with higher mutation frequency had a higher hatchability. The automated homology model building was carried out using crystal structure coordinates of chick HbD. The results indicated that the substitution Met-32(B13)-Leu provides a more hydrophobic environment which leads to higher stability of heme and oxygen affinity of hemoglobin. The occurrence of the mutation Met-32(B13)-Leu is related to the origin of Tibetan chick.
作 者： GOU Xiao LI Ning LIAN Linsheng YAN Dawei ZHANG Hao WU Changxin 作者单位： GOU Xiao,ZHANG Hao,WU Changxin(College of Animal Science and Technology, China Agricultural University, Beijing 100094, China)LI Ning(The National Opened Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100094, China)
LIAN Linsheng,YAN Dawei(College of Animal Science and Technology, Yunnan Agricultural University, Kunming 650201, China)
刊 名： 中国科学C辑（英文版） SCI 英文刊名： SCIENCE IN CHINA (LIFE SCIENCES) 年，卷(期)： 2005 48(6) 分类号： Q95 关键词： Tibetan chick hypoxia incubation hemoglobin homology modeling