Tyrosine Hydroxylase is crucial for maintaining pupal tanning and immunity in Anopheles sinensis.
Tyrosine Hydroxylase is crucial for maintaining pupal tanning and immunity in Anopheles sinensis.
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酪氨酸羟化酶对于维持中华按蚊蛹的晒黑和免疫力至关重要
DOI：
10.1038/srep29835
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发表时间：
2016-07-15
影响因子：
4.6
通讯作者：
Chen B
中科院分区：
文献类型：
--
作者：
Qiao L;Du M;Liang X;Hao Y;He X;Si F;Mei T;Chen B
酪氨酸羟基酶(TH)是黑色素途径的起始酶，催化酪氨酸转化为多巴。尽管TH的表达和调控已经被证明影响昆虫的角质层色素沉积，但到目前为止，还没有直接的功能研究集中在蚊子发育过程中涉及该酶的特定生理过程。在目前的研究中，在中华按蚊蛹中持续高表达的时间段内，ASTH的沉默导致了角质层晒黑和厚度的显著损害，对成虫的羽化造成了严重的障碍。同时，与对照个体相比，干扰个体的黑色素缺乏导致黑化被抑制。因此，防御外来微生物的能力急剧下降。伴随着5个抗菌肽基因基础表达的下调，导致免疫力进一步显着减弱。TH同源物和上游转录因子结合位点的组成在按蚊属中高度保守，这意味着TH介导的功能在按蚊中是至关重要的。这些证据有力地表明TH对按蚊蛹的制革和免疫是必不可少的，并为进一步的研究验证参与黑化途径的关键基因在控制蚊子发育中的作用提供了参考。
Tyrosine hydroxylase (TH), the initial enzyme in the melanin pathway, catalyzes tyrosine conversion into Dopa. Although expression and regulation of TH have been shown to affect cuticle pigmentation in insects, no direct functional studies to date have focused on the specific physiological processes involving the enzyme during mosquito development. In the current study, silencing of AsTH during the time period of continuous high expression in Anopheles sinensis pupae led to significant impairment of cuticle tanning and thickness, imposing a severe obstacle to eclosion in adults. Meanwhile, deficiency of melanin in interference individuals led to suppression of melanization, compared to control individuals. Consequently, the ability to defend exogenous microorganisms declined sharply. Accompanying down-regulation of the basal expression of five antimicrobial peptide genes resulted in further significant weakening of immunity. TH homologs as well as the composition of upstream transcription factor binding sites at the pupal stage are highly conserved in the Anopheles genus, implying that the TH-mediated functions are crucial in Anopheles. The collective evidence strongly suggests that TH is essential for Anopheles pupae tanning and immunity and provides a reference for further studies to validate the utility of the key genes involved in the melanization pathway in controlling mosquito development.