Sequence structure and expression pattern of a novel anionic defensin-like gene from silkworm (Bombyx mori)
Sequence structure and expression pattern of a novel anionic defensin-like gene from silkworm (Bombyx mori)
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DOI：
10.1007/s11033-008-9233-4
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发表时间：
2009-04-01
影响因子：
2.8
通讯作者：
Nakagaki, Masao
中科院分区：
文献类型：
--
作者：
Wen, Hongxiu;Lan, Xiqian;Nakagaki, Masao
在家蚕基因组和表达序列标签数据库中重新发现了防御素样基因BmdefA。BmdefA的开放阅读框编码由22个残基的信号肽、34个残基的前肽和36个残基的成熟肽组成的前肽，分子量为4.0 kDa。成熟肽具有昆虫防御素特有的六个半胱氨酸基序，预测等电点为4.12，表明它是一种新的阴离子防御素。在BmdefA中存在一个内含子，并且在调节区域中存在几个顺式调节元件。在家蚕幼虫的血细胞、丝腺、头部和卵巢中，以及在早期蛹和蛾的脂肪体中组成性高水平转录。BmdefA也被免疫攻击强烈诱导。这些结果表明，BmdefA在免疫和变态中起着重要作用。
A defensin-like gene, BmdefA, was rediscovered in the silkworm genome and expressed sequence tags databases. The open reading frame of BmdefA encodes a prepropeptide consisting of a 22-residue signal peptide, a 34-residue propeptide, and a 36-residue mature peptide with a molecular mass of 4.0 kDa. The mature peptide possesses the characteristic six-cysteine motif of insect defensins, and its predicted isoelectric point is 4.12, indicating it is a novel anionic defensin. An intron is present in BmdefA and several cis-regulatory elements are in the regulating region. It is transcribed constitutively at a high level in the hemocyte, silk gland, head, and ovary of the silkworm larvae, and in the fat body of early-stage pupae and moth. BmdefA is also strongly induced by immune challenge. These results suggest that BmdefA plays an important role in both immunity and metamorphosis.