title: Tyrosine Hydroxylase is crucial for maintaining pupal tanning and immunity in Anopheles sinensis.
abstract: 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.
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Qiao
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Du
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liang
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Youjin
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: He
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Fengling
authors.initials: F
authors.lastname: Si
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Mei
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008543:Melanins / Q000378:metabolism*; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics; D011679:Pupa / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid; D014446:Tyrosine 3-Monooxygenase / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D019476:Insect Proteins; D008543:Melanins; D014446:Tyrosine 3-Monooxygenase