期刊
PARASITOLOGY
卷 137, 期 1, 页码 159-171出版社
CAMBRIDGE UNIV PRESS
DOI: 10.1017/S0031182009990321
关键词
development; immune modulator; stage-specific expression
类别
资金
- Medical Research Council
- Wellcome Trust
- Scottish Government Rural and Environment Research and Analysis Directorate (RERAD)
The transforming growth factor-beta (TGF-beta) gene family regulates critical processes in animal development, and plays a crucial role in regulating the mammalian immune response. We aimed to identify TGF-beta homologues from 2 laboratory model nematodes (Heligmosomoides polygyrus and Nippostrongylus brasiliensis) and 2 major parasites of ruminant livestock (Haemonchus contortus and Teladorsagia circumcincta). Parasite cDNA was used as a template for gene-specific PCR and RACE. Homologues of the TGH-2 subfamily were isolated, and found to differ in length (301, 152, 349 and 305 amino acids respectively), with variably truncated N-terminal pre-proteins. All contained conserved C-terminal active domains (> 85% identical over 115 amino acids) containing 9 cysteine residues, as in C. elegans DAF-7, Brugia malayi TGH-2 and mammalian TGF-beta. Surprisingly, only the H. contortus homologue retained a conventional signal sequence, absent from shorter proteins of other species. RT-PCR assays of transcription showed that in H. contortus and N. brasiliensis expression was maximal in the infective larval stage, and very low in adult worms. In contrast, in H. polygyrus and T. circumcincta, tgh-2 transcription is higher in adults than infective larvae. The molecular evolution of this gene family in parasitic nematodes has diversified the pre-protein and life-cycle expression patterns of TGF-beta homologues while conserving the structure of the active domain.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据