Unusual conservation among genes encoding small secreted salivary gland proteins from a gall midge.
Unusual conservation among genes encoding small secreted salivary gland proteins from a gall midge.
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DOI：
10.1186/1471-2148-10-296
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发表时间：
2010-09-28
影响因子：
3.4
通讯作者：
Hulbert S
中科院分区：
文献类型：
--
作者：
Chen MS;Liu X;Yang Z;Zhao H;Shukle RH;Stuart JJ;Hulbert S
在大多数蛋白质编码基因中，由于选择性限制，在非编码区（内含子和非翻译区）观察到的序列变异比编码区大。在表征的基因和转录编码小分泌唾液腺蛋白（SSSGPs）从黑森蝇，我们发现恰恰相反的模式，在几个家庭的基因的保守性：非编码区高度保守，但编码区是高度可变的。来自SSSGP-1家族的七个基因在基因组的15 kb区域内聚集为一个反向重复和六个串联重复。除了SSSGP-1A 2（一个编码与SSSGP-1A 1编码的蛋白相同的蛋白的基因）之外，其他六个基因由高度多样化的成熟蛋白编码区以及高度保守的区域（包括启动子、5 '-和3'-UTR、信号肽编码区和内含子）组成。这种高度多样化的编码区与基因其余部分的高度保守区相结合的不寻常模式也在其他几组SSSGP编码基因或cDNA中观察到。在亚洲稻瘿蚊的SSSGP cDNA中也发现了这种不寻常的保守模式，但在橙子小麦开花蚊中没有发现。强烈的正选择是多样化的驱动力之一，而一致的同质化可能是序列保守的机制。成熟SSSGPs的快速多样化表明，这些基因处于功能适应的选择压力之下。这些基因的非编码区（包括内含子）的保守性也表明了序列均一化的潜在机制，但尚未完全了解。这一报告将有助于进一步研究寄生虫基因进化和功能适应的遗传机制。
In most protein-coding genes, greater sequence variation is observed in noncoding regions (introns and untranslated regions) than in coding regions due to selective constraints. During characterization of genes and transcripts encoding small secreted salivary gland proteins (SSSGPs) from the Hessian fly, we found exactly the opposite pattern of conservation in several families of genes: the non-coding regions were highly conserved, but the coding regions were highly variable. Seven genes from the SSSGP-1 family are clustered as one inverted and six tandem repeats within a 15 kb region of the genome. Except for SSSGP-1A2, a gene that encodes a protein identical to that encoded by SSSGP-1A1, the other six genes consist of a highly diversified, mature protein-coding region as well as highly conserved regions including the promoter, 5'- and 3'-UTRs, a signal peptide coding region, and an intron. This unusual pattern of highly diversified coding regions coupled with highly conserved regions in the rest of the gene was also observed in several other groups of SSSGP-encoding genes or cDNAs. The unusual conservation pattern was also found in some of the SSSGP cDNAs from the Asian rice gall midge, but not from the orange wheat blossom midge. Strong positive selection was one of the forces driving for diversification whereas concerted homogenization was likely a mechanism for sequence conservation. Rapid diversification in mature SSSGPs suggests that the genes are under selection pressure for functional adaptation. The conservation in the noncoding regions of these genes including introns also suggested potential mechanisms for sequence homogenization that are not yet fully understood. This report should be useful for future studies on genetic mechanisms involved in evolution and functional adaptation of parasite genes.
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影响因子：
5.1
作者：
Bede, JC;Musser, RO;Korth, KL
通讯作者：
Korth, KL
影响因子：
2.3
作者：
Causton, CE;Peck, SB;Landry, B
通讯作者：
Landry, B
影响因子：
4
作者：
Chen, Ming-Shun;Liu, Xiang;Wilde, Gerald E.
通讯作者：
Wilde, Gerald E.
影响因子：
2.6
作者：
Chen, MS;Fellers, JP;Liu, X
通讯作者：
Liu, X
DOI：
10.1126/science.1171663
发表时间：
2009-05-08
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Burdon JJ;Thrall PH
通讯作者：
Thrall PH