Species specificity in major urinary proteins by parallel evolution.
Species specificity in major urinary proteins by parallel evolution.
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DOI：
10.1371/journal.pone.0003280
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发表时间：
2008-09-25
期刊：
影响因子：
3.7
通讯作者：
Stowers L
中科院分区：
文献类型：
--
作者：
Logan DW;Marton TF;Stowers L
物种特有的化学信号，信息素，调节社会行为，如侵略，交配，幼崽哺乳，领土建立和统治。这些线索的身份大部分仍未确定，很少有哺乳动物信息素已被确定。遗传编码信息素可能会表现出几种不同的编码机制：1)多样性，使多种行为能够发出信号；2)动态调节，指示年龄和优势；3)物种特异性。近年来，主要的尿蛋白（Mups）已被证明可以作为基因编码的信息素来调节物种特异性行为。Mups是多种高度相关的蛋白质，它们以组合模式表达，在个体、性别和年龄之间存在差异；足以满足前两个标准。现在我们已经对小鼠Mup基因的内容进行了详细的表征和完整的注释。这使我们能够进一步分析Mup编码多样性的程度，并确定它们编码物种特异性线索的潜力。我们的研究结果表明，小鼠Mup基因簇由两个亚群组成：一个更古老、更多样化的基因和假基因类，以及一个由单基因/假基因对最近的序列重复形成的具有高序列同一性的第二类。先前的研究表明，截断的Mup假基因可能编码一个具有信息素活性的功能性六肽家族。然而，序列比较表明它们的编码潜力有限。对其他9个完整基因组的类似分析发现，Mup基因在不同谱系（包括大鼠、马和灰鼠狐猴）中扩展，独立于其他胎盘哺乳动物中存在的单一祖先Mup。我们的研究结果表明，Mup基因家族的基因组复杂性的增加并不是进化上孤立的，而是一种在哺乳动物中产生与物种特异性功能一致的编码多样性的循环机制。
Species-specific chemosignals, pheromones, regulate social behaviors such as aggression, mating, pup-suckling, territory establishment, and dominance. The identity of these cues remains mostly undetermined and few mammalian pheromones have been identified. Genetically-encoded pheromones are expected to exhibit several different mechanisms for coding 1) diversity, to enable the signaling of multiple behaviors, 2) dynamic regulation, to indicate age and dominance, and 3) species-specificity. Recently, the major urinary proteins (Mups) have been shown to function themselves as genetically-encoded pheromones to regulate species-specific behavior. Mups are multiple highly related proteins expressed in combinatorial patterns that differ between individuals, gender, and age; which are sufficient to fulfill the first two criteria. We have now characterized and fully annotated the mouse Mup gene content in detail. This has enabled us to further analyze the extent of Mup coding diversity and determine their potential to encode species-specific cues. Our results show that the mouse Mup gene cluster is composed of two subgroups: an older, more divergent class of genes and pseudogenes, and a second class with high sequence identity formed by recent sequential duplications of a single gene/pseudogene pair. Previous work suggests that truncated Mup pseudogenes may encode a family of functional hexapeptides with the potential for pheromone activity. Sequence comparison, however, reveals that they have limited coding potential. Similar analyses of nine other completed genomes find Mup gene expansions in divergent lineages, including those of rat, horse and grey mouse lemur, occurring independently from a single ancestral Mup present in other placental mammals. Our findings illustrate that increasing genomic complexity of the Mup gene family is not evolutionarily isolated, but is instead a recurring mechanism of generating coding diversity consistent with a species-specific function in mammals.