Baron Andrea, Veo Kristopher, Angleson Joseph, Dores Robert M
University of Denver, Department of Biological Sciences, Olin Hall 102, 2190 E. Iliff, Denver, Colorado 80210-5212, USA.
Gen Comp Endocrinol. 2009 Mar;161(1):13-9. doi: 10.1016/j.ygcen.2008.11.026. Epub 2008 Dec 7.
Comparative studies support the hypothesis that the proliferation of melanocortin receptor genes (MCRs) in gnathostomes corresponds to the 2R hypothesis for the radiation of gene families in Phylum Chordata. This mini-review will initially focus on the distribution of MCRs in cartilaginous fish and the relationship between the shark MC5R gene and the proposed ancestral MC5R/2R gene. This section will be followed by the results of recent studies on the features of the ligand binding site common to all melanocortin receptors. These data will provide the background for a set of hypotheses to explain the unique ligand selectivity of the MC2 receptor in teleosts and tetrapods.
比较研究支持这样一种假说，即颌口类动物中黑皮质素受体基因（MCRs）的增殖与脊索动物门基因家族辐射的2R假说相对应。本小型综述最初将聚焦于MCRs在软骨鱼类中的分布，以及鲨鱼MC5R基因与推测的原始MC5R/2R基因之间的关系。接下来将阐述近期关于所有黑皮质素受体共有的配体结合位点特征的研究结果。这些数据将为一系列假说提供背景，以解释硬骨鱼和四足动物中MC2受体独特的配体选择性。
