Ellegren H, Mikko S, Wallin K, Andersson L
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Biomedical Centre, Uppsala.
Mol Ecol. 1996 Feb;5(1):3-9. doi: 10.1111/j.1365-294x.1996.tb00286.x.
The Swedish moose was analysed for genetic variability at major histocompatibility complex (MHC) class I and class II DQA, DQB and DRB loci using restriction fragment length polymorphism (RFLP) and single strand conformation polymorphism (SSCP) techniques. Both methods revealed limited amounts of polymorphism. Since the SSCP analysis concerned an expressed DRB gene it can be concluded that the level of functional MHC class II polymorphism, at least at the DRB locus, is low in Swedish moose. DNA fingerprinting was used to determine if the unusual pattern of low MHC variability could be explained by a low degree of genome-wide genetic diversity. Hybridizations with two minisatellite probes gave similarity indices somewhat higher than the average for other natural population, but the data suggest that the low MHC variability cannot be explained by a recent population bottleneck. However, since minisatellite sequences evolve more rapidly than MHC sequences, the low levels of MHC diversity may be attributed to a bottleneck of more ancient origin. The selection pressure for MHC variability in moose may also be reduced and we discuss the possibility that its solitary life style may reduce lateral transmission of pathogens in the population.
利用限制性片段长度多态性（RFLP）和单链构象多态性（SSCP）技术，对瑞典驼鹿主要组织相容性复合体（MHC）I类以及II类的DQA、DQB和DRB基因座的遗传变异性进行了分析。两种方法均显示多态性数量有限。由于SSCP分析涉及一个表达的DRB基因，因此可以得出结论，瑞典驼鹿功能性MHC II类多态性水平，至少在DRB基因座上较低。采用DNA指纹图谱技术来确定MHC变异性低的异常模式是否可以用全基因组遗传多样性程度低来解释。用两种微卫星探针进行杂交，得到的相似性指数略高于其他自然种群的平均水平，但数据表明，MHC变异性低不能用近期的种群瓶颈来解释。然而，由于微卫星序列的进化速度比MHC序列快，MHC多样性水平低可能归因于更古老起源的瓶颈。驼鹿MHC变异性的选择压力也可能降低，我们讨论了其独居生活方式可能减少种群中病原体横向传播的可能性。
