Chen S H, Lin C Y, Kuo C M
Institute of Zoology, Academia Sinica, Taipei, Taiwan.
Mar Biotechnol (NY). 2005 May-Jun;7(3):193-206. doi: 10.1007/s10126-004-0020-5. Epub 2005 Jun 8.
Through multiple sequence alignment and phylogenetic analysis, the subgrouping of the crustacean hyperglycemic hormone (CHH) family was updated using the most complete, nonredundant sequence data set. All sequences from insects were clustered into a distinct subbranch with characters closer to CHH subfamily I. Several sequences that are controversial in their nomenclature and classification are discussed. The motif configuration of CHHs differs from that of molt-inhibiting hormone or gonad-inhibiting hormone in both N and C termini. These two motifs approach each other in tertiary structure models, and the motif preference reveals the critical roles of these regions in functional specificity. Two types of exon organizations of the CHH family genes were observed. Four-exon Chh genes were found in a wide range of pan-crustacean (crustacean and hexapod) taxa, except for the penaeid species, from which the 3-exon Chh genes were reported. Meanwhile, the 3-exon structure was found in the Mih gene and Moih genes from one brachyuran species. Combining gene scan skill and exon splicing rules found in this study, we define three more novel sequences from two insect genomes. The pattern of the exon-exon junction within the mature peptide segment is preserved in all CHH family members.
通过多序列比对和系统发育分析，利用最完整、无冗余的序列数据集更新了甲壳动物高血糖激素（CHH）家族的亚群划分。昆虫的所有序列都聚类到一个独特的亚分支中，其特征更接近CHH亚家族I。讨论了几个在命名和分类上存在争议的序列。CHHs的基序结构在N端和C端均与蜕皮抑制激素或性腺抑制激素不同。在三级结构模型中，这两个基序相互靠近，基序偏好揭示了这些区域在功能特异性中的关键作用。观察到CHH家族基因的两种外显子组织类型。除了报道有3外显子Chh基因的对虾种类外，在广泛的泛甲壳动物（甲壳动物和六足动物）类群中发现了4外显子Chh基因。同时，在一种短尾类动物的Mih基因和Moih基因中发现了3外显子结构。结合本研究中发现的基因扫描技术和外显子剪接规则，我们从两个昆虫基因组中定义了另外三个新序列。成熟肽段内的外显子-外显子连接模式在所有CHH家族成员中均得以保留。
