House spider genome uncovers evolutionary shifts in the diversity and expression of black widow venom proteins associated with extreme toxicity.
House spider genome uncovers evolutionary shifts in the diversity and expression of black widow venom proteins associated with extreme toxicity.
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DOI：
10.1186/s12864-017-3551-7
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发表时间：
2017-02-16
期刊：
影响因子：
4.4
通讯作者：
Garb JE
中科院分区：
文献类型：
--
作者：
Gendreau KL;Haney RA;Schwager EE;Wierschin T;Stanke M;Richards S;Garb JE
黑寡妇蜘蛛因其神经毒性毒液而臭名昭著，这种毒液会导致极端和持久的疼痛。这种不寻常的毒液主要由latrodectins和latrodectins组成，这两个蛋白质家族在黑寡妇Latrodectus属之外几乎不为人所知，由于蜘蛛基因组的缺乏，很难对它们进行研究。利用组织、性别和阶段特异性表达数据，我们分析了最近测序的黑寡妇近亲家蜘蛛（Parasteatoda tepidariorum）的基因组，以研究latrotoxin和latrodectin的多样性、表达和进化。我们在家蜘蛛基因组中发现了至少47个毒素基因，其中许多是串联排列的。latotoxins在预测的结构域和表达上有很大的不同，这意味着它们具有显著的功能多样化。系统发育分析表明，latodectus /Parasteatoda分离后，latodectus / parasteatata大量复制了latodectus毒素，并且它们也与内共生细菌中发现的蛋白质有关。Latrodectin基因数量少于latrotoxins，但分析表明，它们通过复制，倒置和结构域截断从神经肽激素基因中募集毒液功能。虽然latrodectins和其他多肽在家蜘蛛和黑寡妇毒液腺中高度表达，但latrotoxins在家蜘蛛毒液腺中的表达比例要小得多。家蜘蛛的基因组序列为曾经被认为是黑寡妇特有的毒液毒素的进化提供了新的见解。我们的研究结果极大地扩大了latrotoxin基因家族的规模，加强了其狭窄的系统发育分布，并为latrotoxin在蜘蛛和细菌内共生体之间的横向转移提供了额外的证据。此外，我们加强了从外生动物离子转运肽(ITP)/甲壳类高血糖激素（CHH）神经肽超家族中进化出latodectin蛇毒基因的证据。与黑寡妇相比，家蜘蛛中latrotoxin的表达量较低，而且家蜘蛛基因组中缺乏针对脊椎动物的α-latrotoxin基因，这可能是黑寡妇毒液具有极强效力的原因。本文的在线版本（doi:10.1186/s12864-017-3551-7）包含补充材料，授权用户可以使用。
Black widow spiders are infamous for their neurotoxic venom, which can cause extreme and long-lasting pain. This unusual venom is dominated by latrotoxins and latrodectins, two protein families virtually unknown outside of the black widow genus Latrodectus, that are difficult to study given the paucity of spider genomes. Using tissue-, sex- and stage-specific expression data, we analyzed the recently sequenced genome of the house spider (Parasteatoda tepidariorum), a close relative of black widows, to investigate latrotoxin and latrodectin diversity, expression and evolution. We discovered at least 47 latrotoxin genes in the house spider genome, many of which are tandem-arrayed. Latrotoxins vary extensively in predicted structural domains and expression, implying their significant functional diversification. Phylogenetic analyses show latrotoxins have substantially duplicated after the Latrodectus/Parasteatoda split and that they are also related to proteins found in endosymbiotic bacteria. Latrodectin genes are less numerous than latrotoxins, but analyses show their recruitment for venom function from neuropeptide hormone genes following duplication, inversion and domain truncation. While latrodectins and other peptides are highly expressed in house spider and black widow venom glands, latrotoxins account for a far smaller percentage of house spider venom gland expression. The house spider genome sequence provides novel insights into the evolution of venom toxins once considered unique to black widows. Our results greatly expand the size of the latrotoxin gene family, reinforce its narrow phylogenetic distribution, and provide additional evidence for the lateral transfer of latrotoxins between spiders and bacterial endosymbionts. Moreover, we strengthen the evidence for the evolution of latrodectin venom genes from the ecdysozoan Ion Transport Peptide (ITP)/Crustacean Hyperglycemic Hormone (CHH) neuropeptide superfamily. The lower expression of latrotoxins in house spiders relative to black widows, along with the absence of a vertebrate-targeting α-latrotoxin gene in the house spider genome, may account for the extreme potency of black widow venom. The online version of this article (doi:10.1186/s12864-017-3551-7) contains supplementary material, which is available to authorized users.