作者：
Jia-Lin Wang;Qi Zhang;Xu-Sheng Liu（刘绪生）;Yu-Feng Wang
作者机构：
[Xu-Sheng Liu; Jia-Lin Wang; Qi Zhang; Yu-Feng Wang] Laboratory of Genetic Regulation and Integrative Biology, College of Life Science,Central China Normal University, Wuhan 430079, China
会议名称：
The 10th Conference of Insect Physiology, Biochemistry and Molecular Biology(第四届国际昆虫生理生化与分子生物学学术研讨会暨第十届全国昆虫生理生化与分子生物学学术会议)
会议时间：
2013-6-15
会议地点：
南京
会议主办单位：
中国昆虫学会
会议论文集名称：
The 10th Conference of Insect Physiology, Biochemistry and Molecular Biology(第四届国际昆虫生理生化与分子生物学学术研讨会暨第十届全国昆虫生理生化与分子生物学学术会议)论文集
关键词：
HaCTL3;HaCTL7;RD;Helicoverpa armigera
摘要：
<正>C-type lectins play important roles in innate immunity as pattern recognition receptors（PRRs）.Previously,we obtained two C-type lectins HaCTL3and HaCTL7 from the cotton bollworm（Helicoverpa armigera）,
摘要：
BACKGROUND: The heavy metal lead has been shown to be associated with a genotoxic risk. Drosophila melanogaster is a model organism commonly utilized in genetic toxicology testing. The endosymbionts--Wolbachia are now very common in both wild populations and laboratory stocks of Drosophila. Wolbachia may induce resistance to pathogenic viruses, filarial nematodes and Plasmodium in fruit fly and mosquito hosts. However the effect of Wolbachia infection on the resistance of their hosts to heavy metal is unknown. METHODOLOGY/PRINCIPAL FINDINGS: Manipulating the lead content in the diet of Drosophila melanogaster, we found that lead consumption had no different effects on developmental time between Wolbachia-infected (Dmel wMel) and -uninfected (Dmel T) flies. While in Pb-contaminated medium, significantly reduced amount of pupae and adults of Dmel wMel were emerged, and Dmel wMel adults had significantly shorter longevity than that of Dmel T flies. Lead infusion in diet resulted in significantly decreased superoxide dismutase (SOD) activity in Dmel T flies (P<0.05), but not in Dmel wMel flies. Correspondingly, lead cultures induced a 10.8 fold increase in malonaldehyde (MDA) contents in Dmel T larvae (P<0.05). While in Dmel wMel larvae, it resulted in only a 1.3 fold increase. By quantitative RT-PCR, we showed that lead infused medium caused significantly increased expression level of relish and CecA2 genes in Dmel T flies (P<0.01). Lead cultures did not change dramatically the expression of these genes in Dmel wMel flies. CONCLUSIONS/SIGNIFICANCE: These results suggest that Wolbachia infection decreased the resistance of Drosophila to lead likely by limiting the production of peroxides resulted from lead, thus being unable to activate the immunological pathway in the host to prevent them from lead damage. This represents a novel Wolbachia-host interaction and provides information that researchers working on Drosophila toxicology should take in consideration the presence of Wolbachia in the stocks they are analyzing.
作者：
Ya Zheng;Chen Liu;Lin-Ling Yuan;Jia-Lin Wang;Yu-Feng Wang
作者机构：
[Ya Zheng; Chen Liu; Lin-Ling Yuan; Jia-Lin Wang; Yu-Feng Wang] Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan 430079, P.R.China
会议名称：
2012全国发育生物学大会
会议时间：
2012-10-20
会议地点：
西安
会议主办单位：
中国遗传学会;中国细胞生物学学会
会议论文集名称：
2012全国发育生物学大会论文集
摘要：
Wolbachia are obligate endosymbiotic bacteria that infect numerous species of arthropods and nematodes.Wolbachia can induce several reproductive phenotypes in their insect hosts, such as Cytoplasmic incompatibility (CI).CI results in embryo mortality when Wolbachia uninfected eggs are fertilized by sperm from Wolbachia-infected males.Some studies showed that Drosophila male pronucleus can not be formed normally in CI embryo due to aborted chromatin bridge construction in the karyokinesis process.
通讯机构：
[Wang, Yu-Feng] H;Huazhong Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
摘要：
The histone H3.3 chaperone HIRA is essential for chromatin assembly during male pronucleus formation in Drosophila. However, the role of HIRA during fertilization in vertebrates remains unclear. The gibel carp (Carassius auratus gibelio) is a unique gynogenetic crucian carp (gyno-carp). Heterologous sperm nuclei cannot decondense when incorporated in the egg, thus the eggs produce a clonal lineage of all females by typical gynogenesis. In contrast, after entering the egg, homologous sperm can undergo decondensation and sexual reproduction is activated, which may produce both female and male offspring. Therefore, this fish is a useful model for studying the mechanisms of fertilization. Herein, we first compared HIRA expression during embryogenesis between gyno-carp and the gonochoristic color crucian carp (Carassius auratus; gono-carp). In gono-carp, a dramatic reduction of HIRA protein occurs shortly after fertilization, whereas HIRA protein is consistently expressed during embryogenesis of gyno-carp. Next, we used immunodepletion and an in vitro sperm decondensation system, and found that complete removal of HIRA inhibited sperm decondensation in both of the fish. Immunofluorescence localization showed that in the condensed sperm nuclei of gono-carp incubated in gyno-carp egg extracts, HIRA was detected, but neither the histone H2A variant H2af1o nor acetylated histone H4 was observed. These results suggest that HIRA may be a critical factor required for sperm nucleus decondensation, while the defect in deposition of some maternal histones in the sperm nucleus could be one reason why heterologous sperm cannot decondense in the gibel carp egg. Mol. Reprod. Dev. 78: 139-147, 2011. (c) 2011 Wiley-Liss, Inc.
摘要：
Background
Wolbachia are obligate endosymbiotic bacteria that infect numerous species of arthropods and nematodes. Wolbachia can induce several reproductive phenotypes in their insect hosts including feminization, male-killing, parthenogenesis and cytoplasmic incompatibility (CI). CI is the most common phenotype and occurs when Wolbachia-infected males mate with uninfected females resulting in no or very low numbers of viable offspring. However, matings between males and females infected with the same strain of Wolbachia result in viable progeny. Despite substantial scientific effort, the molecular mechanisms underlying CI are currently unknown.
Methodology/Principal Findings
Gene expression studies were undertaken in Drosophila melanogaster and D. simulans which display differential levels of CI using quantitative RT-PCR. We show that Hira expression is correlated with the induction of CI and occurs in a sex-specific manner. Hira expression is significantly lower in males which induce strong CI when compared to males inducing no CI or Wolbachia-uninfected males. A reduction in Hira expression is also observed in 1-day-old males that induce stronger CI compared to 5-day-old males that induce weak or no CI. In addition, Hira mutated D. melanogaster males mated to uninfected females result in significantly decreased hatch rates comparing with uninfected crosses. Interestingly, wMel-infected females may rescue the hatch rates. An obvious CI phenotype with chromatin bridges are observed in the early embryo resulting from Hira mutant fertilization, which strongly mimics the defects associated with CI.
Conclusions/Significance
Our results suggest Wolbachia-induced CI in Drosophila occurs due to a reduction in Hira expression in Wolbachia-infected males leading to detrimental effects on sperm fertility resulting in embryo lethality. These results may help determine the underlying mechanism of CI and provide further insight in to the important role Hira plays in the interaction of Wolbachia and its insect host.
摘要：
Wolbachia are endosymbiotic bacteria that are frequently found in arthropods and nematodes. These maternally inherited bacteria manipulate host reproduction by several mechanisms including cytoplasmic incompatibility (CI). CI is the most common phenotype induced by Wolbachia and results in the developmental arrest of embryos derived from crosses between Wolbachia-infected males and uninfected females. Although the molecular mechanisms of CI are currently unknown, several studies suggest that host sperm is modified by Wolbachia during spermatogenesis. We compared the gene expression of Drosophila melanogaster larval testes with and without the w Mel strain of Wolbachia to identify candidate genes that could be involved in the interaction between Wolbachia and the insect host. Microarray, quantitative RT-PCR and in situ hybridization analyses were carried out on D. melanogaster larval testes to determine the effect of Wolbachia infection on host gene expression. A total of 296 genes were identified by microarray analysis to have at least a 1.5 fold change [q-value < 5%] in expression. When comparing Wolbachia-infected flies to uninfected flies, 167 genes were up-regulated and 129 genes down-regulated. Differential expression of genes related to metabolism, immunity, reproduction and other functions were observed. Quantitative RT-PCR (qRT-PCR) confirmed 12 genes are differentially expressed in the testes of the 3rd instar larvae of Wolbachia-infected and uninfected flies. In situ hybridization demonstrated that Wolbachia infection changes the expression of several genes putatively associated with spermatogenesis including JH induced protein-26 and Mst84Db, or involved in immune (kenny) or metabolism (CG4988-RA). Wolbachia change the gene expression of 296 genes in the larval testes of D. melanogaster including genes related to metabolism, immunity and reproduction. Interestingly, most of the genes putatively involved in immunity were up-regulated in the presence of Wolbachia. In contrast, most of the genes putatively associated with reproduction (especially spermatogenesis) were down-regulated in the presence of Wolbachia. These results suggest Wolbachia may activate the immune pathway but inhibit spermatogenesis. Our data provide a significant panel of candidate genes that may be involved in the interaction between Wolbachia and their insect hosts. This forms a basis to help elucidate the underlying mechanisms of Wolbachia-induced CI in Drosophila and the influence of Wolbachia on spermatogenesis.
