Syngnathids (seahorses, pipefishes and seadragons) exhibit an array of morphological innovations including loss of pelvic fins, a toothless tubular mouth and male pregnancy. They comprise two subfamilies: Syngnathinae and Nerophinae. Genomes of three Syngnathinae members have been analyzed previously. In this study, we have sequenced the genome of a Nerophinae member, the Manado pipefish (Microphis manadensis), which has a semi-enclosed brood pouch. Comparative genomic analysis revealed that the molecular evolutionary rate of the four syngnathids is higher than that of other teleosts. The loss of all but one P/Q-rich SCPP gene in the syngnathids suggests a role for the lost genes in dentin and enameloid formation in teleosts. Genome-wide comparison identified a set of 118 genes with parallel identical amino acid substitutions in syngnathids and placental mammals. Association of some of these genes with placental and embryonic development in mammals suggests a role for them in syngnathid pregnancy.

中文翻译：

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比较基因组学揭示了合颌鱼类的共同基因组变化以及与胎盘哺乳动物的遗传趋同特征

Syngnathids（海马、尖嘴鱼和海龙）表现出一系列形态创新，包括失去腹鳍、无牙管状嘴和雄性怀孕。它们包括两个亚科：Syngnathinae 和 Nerophinae。先前已经分析了三个 Syngnathinae 成员的基因组。在这项研究中，我们对一种 Nerophiae 成员 Manado pipefish ( Microphis manadensis)的基因组进行了测序。)，它有一个半封闭的育雏袋。比较基因组分析表明，四种合颌动物的分子进化率高于其他硬骨鱼类。除一个富含 P/Q 的 SCPP 基因外，合颌动物中所有缺失的基因都表明缺失的基因在硬骨鱼的牙本质和釉质形成中起作用。全基因组比较确定了一组 118 个基因，在合颌和胎盘哺乳动物中具有平行相同的氨基酸替换。这些基因中的一些与哺乳动物胎盘和胚胎发育的关联表明它们在合颚妊娠中发挥作用。