Molecular characterization of insulin-like peptides in the yellow fever mosquito, Aedes aegypti:: Expression, cellular localization, and phylogeny
Molecular characterization of insulin-like peptides in the yellow fever mosquito, Aedes aegypti:: Expression, cellular localization, and phylogeny
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DOI：
10.1016/j.peptides.2006.07.016
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发表时间：
2006-11-01
期刊：
影响因子：
3
通讯作者：
Brown, Mark R.
中科院分区：
文献类型：
--
作者：
Riehle, Michael A.;Fan, Yongliang;Brown, Mark R.
胰岛素样肽是高等真核生物代谢、生殖和衰老的关键调节因子。在这里，我们提出的识别，表达和组织定位的8个基因编码的胰岛素样肽（ILP）的黄热病蚊子，埃及伊蚊。所有八种ILP都具有胰岛素超家族的保守特征，即由连续信号肽、B、C和A肽组成的前原肽。然而，其中一种ILP具有截短的C肽和羧基末端延伸，其特征与胰岛素生长因子一致。五个ILP的成绩单主要发生在幼虫，蛹和成年蚊子的头部（大脑）。另外两个基因的转录本，其中之一是假定的胰岛素生长因子，存在于所有阶段的头部，胸部和肾脏。最终ILP主要表达于腹部。两种不同的ILP抗血清的免疫细胞化学结果显示，在神经系统和中肠，证实了这些表达模式的存在细胞定位。三个ILP基因紧密相连，只有第一个ILP基因的5'区可能足以作为启动子，表明这些基因形成真核操纵子。这三个ILP几乎相同的表达模式支持这一观点。最后，对双翅目三种昆虫的ILP进行了系统发育关系分析。埃及伊蚊，非洲疟疾蚊子（冈比亚按蚊），和黑腹果蝇是了解昆虫ILP的结构和功能多样性的一步。(c)2006年爱思唯尔公司All rights reserved.
Insulin-like peptides are key regulators of metabolism, reproduction, and senescence in higher eukaryotic organisms. Here we present the identification, expression, and tissue localization of eight genes encoding insulin-like peptides (ILPs) in the yellow fever mosquito, Aedes aegypti. All eight ILPs share the conserved features of the insulin superfamily as prepropeptides consisting of contiguous signal, B, C, and A peptides. However, one of the ILPs has a truncated C peptide and a carboxy terminal extension, features consistent with insulin growth factors. Transcripts for five of the ILPs occurred predominantly in the heads (brains) of larval, pupal, and adult mosquitoes. Transcripts of two other genes, one of which was the putative insulin growth factor, were present in the head, thorax and abdomens of all stages. The final ILP was predominantly expressed in abdomen. Results from immunocytochemistry with two different ILP antisera showed cellular localizations in the nervous system and midgut that corroborated the existence of these expression patterns. Three of the ILP genes are so closely linked that only the 5' region of the first ILP gene likely suffices as a promoter, indicating that these genes form a eukaryotic operon. The nearly identical expression pattern of these three ILPs supported this idea. Finally, the phylogenetic relationship of ILPs from three dipteran species, Ae. aegypti, the African malaria mosquito (Anopheles gambiae), and Drosophila melanogaster is presented as a step towards understanding the structural and functional diversity of insect ILPs. (c) 2006 Elsevier Inc. All rights reserved.