Insect Biochemistry and Molecular Biology最新文献

{"title":"Identification and pharmacological characterization of pH-sensitive chloride channels in the fall armyworm, Spodoptera frugiperda","authors":"Wei Wang ,&nbsp;Jia-Sheng Chen ,&nbsp;Pei-Yun He ,&nbsp;Mo-Han Zhang ,&nbsp;Hai-Qun Cao ,&nbsp;Subba Reddy Palli ,&nbsp;Cheng-Wang Sheng","doi":"10.1016/j.ibmb.2024.104243","DOIUrl":"10.1016/j.ibmb.2024.104243","url":null,"abstract":"<div><div>The pH-sensitive chloride channels (pHCls) are unique to invertebrates and play crucial roles in fluid regulation, food selection, and intake. In this study, we identified and isolated two cDNAs encoding the <em>Sf</em>pHCl1 and <em>Sf</em>pHCl2 subunits from the fall armyworm, <em>Spodoptera frugiperda</em>. Both subunits exhibited similar expression patterns. When expressed in <em>Xenopus laevis</em> oocytes, <em>Sf</em>pHCl1 and <em>Sf</em>pHCl2 formed functional chloride channels with reversal potentials indicative of chloride selectivity. Shifts in extracellular pH from acidic to alkaline conditions induced inward currents in both <em>Sf</em>pHCl1 and <em>Sf</em>pHCl2, with EC₅₀ values of pH 8.24 and 8.49, respectively. Zinc ions (Zn²⁺) and the insecticide emamectin benzoate (EB) also activated concentration-dependent inward currents in these channels, whether expressed individually or co-expressed. Notably, <em>Sf</em>pHCl1 and <em>Sf</em>pHCl2 channels exhibited significant differences in their activation and deactivation time constants. These findings elucidate the biophysical and pharmacological characteristics of pH-sensitive, zinc-gated chloride channels, which, being exclusive to invertebrates, present a promising target for the development of highly specific insecticides.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104243"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expansion of three types of transposon superfamilies within 25 Mya lead to large genome size of a rice insect pest","authors":"Bingbing He ,&nbsp;Yuyang Cong ,&nbsp;Le Xu ,&nbsp;Ying Liu","doi":"10.1016/j.ibmb.2024.104251","DOIUrl":"10.1016/j.ibmb.2024.104251","url":null,"abstract":"<div><div>The brown planthoppers (BPH, <em>Nilaparvata lugens)</em>, white backed planthopper (WBPH, <em>Sogatella furcifera</em>) and small brown planthopper (SBPH, <em>Laodelphax striatellus</em>) are widely distributed rice insect pests, causing huge annual yield loss of rice production. Though these three planthoppers belong to the same family, Delphacidae of Hemiptera, their genome sizes (GS) are very different, ranging from 541 to 1088 Mb. To uncover the main factors driving GS changes of three planthoppers, we first estimated the GS of their ancestor Fulgoroidea, to be 794.33 Mb, indicating GS expansion in BPH but contraction in SBPH and WBPH. Next, we identified repetitive sequences and compared the TE landscapes, showed that three types of transposon superfamilies, hAT, Tc1-Mariner and Gypsy, expanded within 25 Mya in BPH. In addition, BPH kept ancient TEs of Fulgoroidea dated back to 175 Mya, while SBPH and WBPH have lost most of these ancient TEs. Here, we present evidence that the gain of recently expanded TEs driving the GS expansion and loss of ancient TEs leading to the GS contraction, providing new insights into the mechanism of GS variation.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104251"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CRISPR/Cas9-mediated knockout of Tektin 4-like gene (TEKT4L) causes male sterility of Cydia pomonella","authors":"Zihan Wei ,&nbsp;Chang Wang ,&nbsp;Xinyue Zhang ,&nbsp;Yuntong Lv ,&nbsp;Yuting Li ,&nbsp;Ping Gao ,&nbsp;Xueqing Yang","doi":"10.1016/j.ibmb.2025.104257","DOIUrl":"10.1016/j.ibmb.2025.104257","url":null,"abstract":"<div><div>The sterile insect technique (SIT) is a well-established and environmentally benign method for population control. Identifying genes that regulate insect fertility while preserving growth and development is crucial for implementing a novel SIT-based pest management approach utilizing CRISPR/Cas9 to target these genes for genetic manipulation. Tektin (TEKT), an essential alpha-helical protein pivotal in sperm formation due to its role in cilia and flagella assembly, has garnered attention. In this study, we identified 7 TEKT genes in the testis of <em>Cydia pomonella</em>, a globally invasive fruit pest. Notably, <em>Tektin4-like</em> (<em>TEKT4L</em>) displayed the highest expression level in male adult especially the testes, suggesting its significance in reproductive processes. By utilizing CRISPR/Cas9 technology to knockout <em>TEKT4L</em>, male sterility was induced, showcasing dominant inherited. When wild-type (WT) females mated with TEKT4L^−/− males, eggs laying proceeded normally, but the hatching rate was dramatically reduced, with only 15.49% progressing to the eyespot stage and 68.86% failing to develop normally. The reproductive fitness of TEKT4L^−/− males was robust enough to facilitate the transmission of genetic modifications efficiently within the <em>C.pomonella</em> population, yielding a small number of viable offspring. Subsequent cage trials demonstrated the effectiveness of this population in suppressing laboratory populations of <em>C.pomonella</em>, achieving notable results with a relatively low release ratio (TEKT4L^−/−<em>♂</em>: WT<em>♂</em>: WT<em>♀</em> = 5:1:5). Consequently, the targeted disruption of the <em>TEKT4L</em> gene holds promise as a fundamental element in a novel pest control strategy against <em>C. pomonella</em>.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104257"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CLIPA protein pairs function as cofactors for prophenoloxidase activation in Anopheles gambiae","authors":"Yang Wang ,&nbsp;Qiao Jin ,&nbsp;Michael R. Kanost ,&nbsp;Haobo Jiang","doi":"10.1016/j.ibmb.2024.104254","DOIUrl":"10.1016/j.ibmb.2024.104254","url":null,"abstract":"<div><div>Insect prophenoloxidases (proPO) are activated during immune responses by a proPO activating protease (PAP) in the presence of a high molecular weight cofactor assembled from <strong>s</strong>erine <strong>p</strong>rotease <strong>h</strong>omologs (SPH) that lack proteolytic activity. PAPs and the SPHs have a similar architecture, with an amino-terminal clip domain and a carboxyl-terminal protease domain. The SPHs belong to CLIPA subfamily of SP-related proteins. In <em>Manduca sexta</em>, a well characterized biochemical model system for insect immunity, the functional SPH cofactor contains one molecule each from two SPH subfamilies, SPH-I and SPH-II. In <em>Anopheles gambiae</em>, three SPHI-SPHII pairs (CLIPs A4-A6, A4-A7Δ, and A4-A12) were previously reported as cofactors for CLIPB9-mediated activation of proPO2 and proPO7. In this study, we produced recombinant proteins for two splicing variants of CLIPA7, proCLIPA7s (s for short), proCLIPA7f (f for full-length) and proCLIPA14. We cleaved each along with proCLIPA4 using <em>M. sexta</em> PAP3 and found that the CLIPA pairs A4-A7s and A4-A14 are better than A4-A7f in generating highly active PO2 or PO7. CLIPA7f and CLIPA7s, products of alternative splicing, have different strengths as cofactors in combination with CLIPA4. Because mRNA for CLIPA7f is expressed at a significantly higher level than CLIPA7s, cofactors with the weaker combination A4-A7f may predominate in hemolymph, resulting in a potential dampening effect on proPO activation as a regulatory mechanism for altering the strength of the melanization response. <em>A. gambiae</em> CLIPB10x_a is involved in proPO activation but its role as a PAP was not established using mosquito proPOs. Here we showed that factor Xa-treated proCLIPB10_Xa activated proCLIPs A7s, A7f, A14, A4 (poorly), and proPO2. At higher concentrations, CLIPB10x_a efficiently activated proPO2 in the absence of a cofactor, but at low concentrations it required a CLIPA cofactor, suggesting that highly active PO2 can be generated at low concentration of CLIPB10 in cooperation with an SPH cofactor <em>in vivo</em>. Using cofactors generated by PAP3, we demonstrated the order of efficacy for proPO2 activation by B10_Xa is A4-A6 &gt; A4-A14 or A4-A7s &gt; A4-A7f &gt; A4-A12. This agrees with their relative strengths as cofactors for proPO2 and proPO7 activation by <em>M. sexta</em> PAP3. In summary, we further developed an <em>in vitro</em> assay system to elucidate biochemical details of the complex process of proPO activation in <em>A. gambiae</em>.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104254"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142969021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Troponin C is required for copulation and ovulation in Nilaparvata lugens","authors":"Luyao Peng ,&nbsp;Cui Zhang ,&nbsp;Jinjin Ren ,&nbsp;Yaxin Liu ,&nbsp;Yanyuan Bao","doi":"10.1016/j.ibmb.2025.104258","DOIUrl":"10.1016/j.ibmb.2025.104258","url":null,"abstract":"<div><div>Troponin C (TnC) is a calcium-binding subunit of the troponin complex that regulates muscle contraction in animals. However, the physiological roles of TnC, especially in insect development and reproduction, remain largely unknown. We identified seven <em>TnC</em> genes encoding four EF-hand motif protein in the rice pest, the brown planthopper <em>Nilaparvata lugens.</em> This species has emerged as an ideal model insect to study gene functions because of the availability of its complete genome sequence and of the susceptibility to RNA interference (RNAi). RT-qPCR combined with <em>in situ</em> hybridization showed that <em>TnCⅠ</em> was highly expressed in the bursa copulatrix of ovaries. RNAi-mediated knockdown of <em>TnCⅠ</em> in 2nd-to 5th-instar nymphs generated significantly lethal deficits, and also led to copulation and ovulation failure in adult females, although males displayed appropriate mating behavior. These new findings provide insights into understanding the physiological functions of <em>TnCⅠ</em> in the survival of, and female reproductive success, in <em>N. lugens.</em> Thus, this gene could be used as a target to explore methods for pest control of this important species.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104258"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142997496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentially spliced mitochondrial CYP419A1 contributes to ethiprole resistance in Nilaparvata lugens","authors":"B. Zeng ,&nbsp;A.J. Hayward ,&nbsp;A. Pym ,&nbsp;A. Duarte ,&nbsp;W.T. Garrood ,&nbsp;S-F Wu ,&nbsp;C-F Gao ,&nbsp;C. Zimmer ,&nbsp;M. Mallott ,&nbsp;T.G.E. Davies ,&nbsp;R. Nauen ,&nbsp;C. Bass ,&nbsp;B.J. Troczka","doi":"10.1016/j.ibmb.2025.104260","DOIUrl":"10.1016/j.ibmb.2025.104260","url":null,"abstract":"<div><div>The brown planthopper <em>Nilaparvata lugens</em> is one of the most economically important pests of cultivated rice in Southeast Asia. Extensive use of insecticide treatments, such as imidacloprid, fipronil and ethiprole, has resulted in the emergence of multiple resistant strains of <em>N. lugens</em>. Previous investigation of the mechanisms of resistance to imidacloprid and ethiprole demonstrated that overexpression and qualitative changes in the cytochrome P450 gene <em>CYP6ER1</em> lead to enhanced metabolic detoxification of these compounds. Here, we present the identification of a secondary mechanism enhancing ethiprole resistance mediated by differential splicing and overexpression of CYP419A1, a planthopper-specific, mitochondrial P450 gene. Although metabolic resistance to insecticides is usually mediated by overexpression of P450 genes belonging to either CYP 3 or 4 clades, we validate the protective effect of over-expression of CYP419A1, <em>in vivo,</em> using transgenic <em>Drosophila melanogaster.</em> Additionally, we report some unusual features of both the CYP419A1 gene locus and protein, which include, altered splicing associated with resistance, a non-canonical heme-binding motif and an extreme 5’ end extension of the open reading frame. These results provide insight into the molecular mechanisms underpinning resistance to insecticides and have applied implications for the control of a highly damaging crop pest.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104260"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The powers and perils of bug editing","authors":"Helena Araujo","doi":"10.1016/j.ibmb.2024.104253","DOIUrl":"10.1016/j.ibmb.2024.104253","url":null,"abstract":"<div><div>Triatomine insects of the Hemiptera order are vectors of the neglected Chagas disease, that inflicts a great health burden in the Americas. Vector control has been recognized as a fundamental aspect to fight disease spread. However, besides the use of insecticides, no transgenic or gene editing tools have been developed for these insects, limiting the widespread use of biological control strategies. Here I present a personal account in trying to develop gene editing tools for triatomines. I highlight the major challenges we have faced, the efforts we have made to overcome these obstacles, and the hurdles that still lie ahead. I deliver no magic path to guide you through the perilous land of kissing bug gene editing but rather lay down a few rules we have learned that may help ease your journey.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"177 ","pages":"Article 104253"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osmoregulation by sucrose isomerization in the phloem-feeding whitefly Bemisia tabaci involves members of the glycoside hydrolase family 13","authors":"Dor Wintraube ,&nbsp;Yonatan Sadeh ,&nbsp;Ofer Aidlin-Harari ,&nbsp;Yehudit Amor ,&nbsp;Shai Morin ,&nbsp;Osnat Malka","doi":"10.1016/j.ibmb.2025.104266","DOIUrl":"10.1016/j.ibmb.2025.104266","url":null,"abstract":"<div><div>A phloem-sap based diet requires unique enzymatic skills for regulating the osmotic pressure differences in the gut lumen between the sucrose-rich ingested sap and the body fluids, which can lead to desiccation and death. In the phloem-feeding whitefly <em>Bemisia tabaci</em>, members of the glycoside hydrolase family 13 (GH13) are likely to play a critical role in mitigating this risk by oligomerizing and isomerizing the products of sucrose hydrolysis. So far, however, the identities of the family members acting as sucrose isomerases (mainly isomerizing trehalulose) remain unknown. In this study, we focused on four putative sucrose isomerase coding genes of <em>B. tabaci</em> that belong to the GH13 family. The four coding genes were selected based on their phylogeny, expression patterns, and motif analyses. We used artificial diets of sucrose and dsRNA to knockdown the expression of each of the target genes and analyzed the sugar composition of the secreted honeydew. We found that in all cases, gene silencing resulted in a significant reduction of the fractions of trehalulose accompanied by an increase in the fractions of the trisaccharide melezitose, suggesting that the insects attempt to compensate for the inability to isomerize sucrose by synthesizing oligosaccharides. In addition, we found that the downregulation of the target genes also resulted in a significant increase in the mortality rates of the silenced insects and a significant delay in the development of their progeny. Taken together, these findings demonstrate the importance of the osmoregulation-by-isomerization strategy in <em>B. tabaci.</em></div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"178 ","pages":"Article 104266"},"PeriodicalIF":3.2,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peroxiredoxin 6 is essential for the posttranslational activation of xanthine dehydrogenase in the uric acid synthesis of Bombyx mori","authors":"Tsuguru Fujii ,&nbsp;Masato Hino ,&nbsp;Toshiaki Fujimoto ,&nbsp;Kohei Kakino ,&nbsp;Yu Kaneko ,&nbsp;Hiroaki Abe ,&nbsp;Jae Man Lee ,&nbsp;Takahiro Kusakabe ,&nbsp;Toru Shimada","doi":"10.1016/j.ibmb.2025.104264","DOIUrl":"10.1016/j.ibmb.2025.104264","url":null,"abstract":"<div><div>We identified a novel mutant of <em>Bombyx mori</em>, designated as male-absent oily (genetic symbol: <em>om</em>). The larval integument of this mutant is translucent due to a lack of uric acid in the integument. This mutation is Z-linked, and as mutant females are infertile, it is impossible to obtain <em>om</em> homozygous males. Using positional cloning combined with RNA-seq analysis, we identified a 1-bp deletion in the <em>B. mori peroxiredoxin 6</em> (<em>BmPrx6</em>) gene. CRISPR/Cas9 knockout of <em>BmPrx6</em> resulted in a translucent larval integument, indicating <em>BmPrx6</em> as the causative gene for the <em>om</em> locus. Xanthine dehydrogenase (XDH)/xanthine oxidase (XO) is a key enzyme for uric acid synthesis. Injection of bovine XO into <em>om</em> mutants rescued the translucent phenotype, indicating that <em>om</em> is a mutant with defective XDH activity. To investigate XDH in <em>B. mori</em>, we generated a FLAG-tagged XDH gene using the CRISPR/Cas9 knock-in approach. Western blot analysis of XDH in <em>om</em> mutants revealed that <em>BmPrx6</em> is crucial for the posttranslational activation of XDH. The role of <em>BmPrx6</em> in regulating XDH activity is discussed.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"178 ","pages":"Article 104264"},"PeriodicalIF":3.2,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bicarbonate, calcium ions, hydrogen peroxide and trypsin modulate activation of Anopheles gambiae sperm motility and protein tyrosine phosphorylation","authors":"Vincent O. Nyasembe ,&nbsp;Claire E. Schregardus ,&nbsp;Priscila Bascunan ,&nbsp;Catherine M. Steele ,&nbsp;Mark Q. Benedict ,&nbsp;Ellen M. Dotson","doi":"10.1016/j.ibmb.2025.104265","DOIUrl":"10.1016/j.ibmb.2025.104265","url":null,"abstract":"<div><div>With the increasing concern of potential loss of transgenic mosquitoes which are candidates as new tools for mosquito-borne disease control, methods for cryopreservation are actively under investigation. Methods to cryopreserve <em>Anopheles gambiae</em> sperm have recently been developed, but there are no artificial insemination or <em>in vitro</em> fertilization tools available. As a step to achieve this, we sought to identify a suitable medium for <em>in vitro</em> incubation of <em>An. gambiae</em> sperm and to tease out critical components that are involved in the sperm motility activation process. Using two cell viability assays, we identified the Biggers-Whitten-Whittingham (BWW) medium as suitable for <em>in vitro</em> incubation of <em>An. gambiae</em> sperm isolated from testes. We then modified the medium for motility assays by testing different HCO₃⁻ and Ca²⁺ concentrations. Our results show that there is an HCO₃⁻ and Ca²⁺ concentration-dependent activation of <em>An. gambiae</em> sperm motility. We further demonstrated that H₂O₂ can be produced by the testes <em>in vitro</em> and that the addition of 5.3 μM of H₂O₂ to the medium improves sperm motility and increases protein tyrosine phosphorylation in <em>An. gambiae</em>. Finally, we show a dose-dependent activation of sperm motility by the addition of trypsin to the medium and more than a 2-fold increase in sperm motility when modified BWW (mBWW) medium is supplemented with H₂O₂ and trypsin. Our <em>in vitro</em> results suggest that protein tyrosine phosphorylation, intracellular ionic influx, intrinsic production of H₂O₂ and trypsin-like proteases play a vital role in signal transduction that leads to the activation of <em>An. gambiae</em> sperm motility.</div></div>","PeriodicalId":330,"journal":{"name":"Insect Biochemistry and Molecular Biology","volume":"178 ","pages":"Article 104265"},"PeriodicalIF":3.2,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}