Extensive sequence conservation among insect, nematode, and vertebrate vitellogenins reveals ancient common ancestry
Extensive sequence conservation among insect, nematode, and vertebrate vitellogenins reveals ancient common ancestry
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DOI：
10.1007/pl00006164
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发表时间：
1997-04-01
影响因子：
3.9
通讯作者：
Raikhel, AS
中科院分区：
文献类型：
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作者：
Chen, JS;Sappington, TW;Raikhel, AS
大多数卵生动物的卵都含有一种称为卵黄蛋白原（Vg）的蛋白质，它是卵黄的主要成分。直到最近，推导的氨基酸序列仅可从脊椎动物和线虫的Vgs，这被证明是同源的。现在已知几种昆虫Vg的序列，但早期尝试与脊椎动物和线虫Vg进行成对比对是有问题的，导致关于昆虫Vg与其他动物的关系有多密切的相互矛盾的结论。在这篇论文中，我们证明，昆虫VE序列可以确信地彼此对齐沿着他们的整个长度和多个脊椎动物和线虫Vg序列沿沿着他们的跨度。虽然分歧是高的，保护昆虫，脊椎动物和线虫之间的Vg序列是广泛的优势，甘氨酸，脯氨酸，半胱氨酸残基之间严格保守的氨基酸，建立决定性的，从三个门的Vg是同源的。最不确定比对的区域主要在昆虫和脊椎动物的多丝氨酸结构域中及其周围，这些结构域不是同源的。系统发育重建的基础上的序列一致性表明，昆虫谱系是最分歧的，哺乳动物血清蛋白，载脂蛋白B-100，从Vg祖先后，线虫/脊椎动物的分歧。
The eggs of most oviparous animals are provisioned with a class of protein called vitellogenin (Vg) which is stored as the major component of yolk. Until recently, deduced amino acid sequences were available only from vertebrate and nematode Vgs, which proved to be homologous. The sequences of several insect Vgs are now known, but early attempts at pairwise alignments with vertebrate and nematode Vgs have been problematic, leading to conflicting conclusions about how closely insect Vgs are related to the others. Ln this paper we demonstrate that insect VE sequences can be confidently aligned with one another along their entire lengths and with multiple vertebrate and nematode Vg sequences along most of their spans. Although divergence is high, conservation among insect, vertebrate, and nematode Vg sequences is widespread with a preponderance of glycine, proline, and cysteine residues among strictly conserved amino acids, establishing conclusively that Vgs from the three phyla are homologous. Areas of least-certain alignment are primarily in and around insect and vertebrate polyserine domains which are not homologous. Phylogenetic reconstructions of Vgs based on sequence identities indicate that the insect lineage is the most diverged and that the mammalian serum protein, apolipoprotein B-100, arose from a Vg ancestor after the nematode/vertebrate divergence.