Roller Ladislav, Yamanaka Naoki, Watanabe Ken, Daubnerová Ivana, Zitnan Dusan, Kataoka Hiroshi, Tanaka Yoshiaki
Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia.
Insect Biochem Mol Biol. 2008 Dec;38(12):1147-57. doi: 10.1016/j.ibmb.2008.04.009.
Cloning-based approach combining homology search in the Bombyx genome sequence and Rapid Amplification of cDNA Ends (RACE) resulted in annotation of 23 neuropeptide genes and different splicing variants of three genes. In total 37 neuropeptide genes in addition to bombyxin gene family have been identified in Bombyx. Comparison of available insect neuropeptide genes revealed that the silkworm genome contains most conserved neuropeptide genes except those encoding proctolin, vasopressin-like peptide and neuropeptide-like precursor 2. In addition, we identified several paralogous neuropeptide genes which have not been found in other insects. The Bombyx genome contains a triplet of paralogous genes encoding adipokinetic hormones (AKH), two genes encoding different neuropeptide Fs (NPFs) and a tandem of related SIFamide and IMFamide genes. A novel gene coding for CCHamide was cloned and its expression in the CNS and midgut was demonstrated. Differential splicing was observed for the first time in transcripts for diuretic hormones and cardioacceleratory peptides 2b. Most paralogous genes or splicing variants of the same gene showed different expression patterns in the central nervous system (CNS). These results suggest that unique duplication and differential expression of several neuropeptide genes occurred during the evolution in Bombyx. This may be an effective mechanism for functional diversification of conserved neuropeptides.
基于克隆的方法，结合家蚕基因组序列中的同源性搜索和cDNA末端快速扩增（RACE），对23个神经肽基因和3个基因的不同剪接变体进行了注释。在家蚕中，除了家蚕素基因家族外，总共鉴定出37个神经肽基因。对现有昆虫神经肽基因的比较表明，家蚕基因组包含大多数保守的神经肽基因，但不包括编码促肠动肽、血管加压素样肽和神经肽样前体2的基因。此外，我们还鉴定出了一些在其他昆虫中未发现的旁系同源神经肽基因。家蚕基因组包含一组编码脂肪动激素（AKH）的旁系同源基因、两个编码不同神经肽F（NPF）的基因以及一组相关的SIF酰胺和IMF酰胺基因。克隆了一个编码CCH酰胺的新基因，并证明了其在中枢神经系统和中肠中的表达。在利尿激素和心脏加速肽2b的转录本中首次观察到差异剪接。大多数旁系同源基因或同一基因的剪接变体在中枢神经系统（CNS）中表现出不同的表达模式。这些结果表明，家蚕在进化过程中发生了几个神经肽基因的独特复制和差异表达。这可能是保守神经肽功能多样化的一种有效机制。
