Identification and Characterization of Seminal Fluid Proteins in the Asian Tiger Mosquito, Aedes albopictus

Aedes albopictus. PLoS Negl Trop Dis 8(6): e2946. doi:10.1371/journal.pntd.0002946 Identification and Characterization of Seminal Fluid Proteins in the Asian Tiger Mosquito, Aedes albopictus Laura K. Sirot 0 Kathryn E. Boes 0 Jose M. C. Ribeiro 0 Alex Wong 0 Laura C. Harrington 0 Mariana F. Wolfner 0 Rhoel Ramos Dinglasan, Johns Hopkins Bloomberg School of Public Health, United States of America 0 1 Department of Biology, College of Wooster, Wooster, Ohio, United States of America, 2 Vector Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases , Rockville, Maryland , United States of America, 3 Department of Biology, Carleton University , Ottawa, Ontario , Canada , 4 Department of Entomology, Cornell University , Ithaca , New York, United States of America, 5 Department of Molecular Biology and Genetics, Cornell University , Ithaca, New York , United States of America The Asian tiger mosquito (Aedes albopictus) is an important vector for pathogens that affect human health, including the viruses that cause dengue and Chikungunya fevers. It is also one of the world's fastest-spreading invasive species. For these reasons, it is crucial to identify strategies for controlling the reproduction and spread of this mosquito. During mating, seminal fluid proteins (Sfps) are transferred from male mosquitoes to females, and these Sfps modulate female behavior and physiology in ways that influence reproduction. Despite the importance of Sfps on female reproductive behavior in mosquitoes and other insects, the identity of Sfps in Ae. albopictus has not previously been reported. We used transcriptomics and proteomics to identify 198 Sfps in Ae. albopictus. We discuss possible functions of these Sfps in relation to Ae. albopictus reproduction-related biology. We additionally compare the sequences of these Sfps with proteins (including reported Sfps) in several other species, including Ae. aegypti. While only 72 (36.4%) of Ae. albopictus Sfps have putative orthologs in Ae. aegypti, suggesting low conservation of the complement of Sfps in these species, we find no evidence for an elevated rate of evolution or positive selection in the Sfps that are shared between the two Aedes species, suggesting high sequence conservation of those shared Sfps. Our results provide a foundation for future studies to investigate the roles of individual Sfps on feeding and reproduction in this mosquito. Functional analysis of these Sfps could inform strategies for managing the rate of pathogen transmission by Ae. albopictus. - Funding: This study was partly supported by a grant from the National Institutes of Health (R01- AI09549) to LCH and MFW (http://nih.gov). This study was partly supported by a grant from the Intramural Research Program of the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health (ZIA AI000810-16) to JMCR. Because JMCR is a government employee and this is a government work, the work is in the public domain in the United States. Notwithstanding any other agreements, the NIH reserves the right to provide the work to PubMedCentral for display and use by the public, and PubMedCentral may tag or modify the work consistent with its customary practices. You can establish rights outside of the U.S. subject to a government use license (http://www.niaid.nih.gov/about/organization/dir/Pages/default.aspx). This study was partly supported by a grant from the National Institutes of Health (P30 CA016058) at the Ohio State University (http://nih.gov/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. Aedes albopictus, the Asian tiger mosquito, is an important species from both an epidemiological and an ecological perspective. Epidemiologically, it has the potential ability to transmit over 20 viruses [1,2], and it plays a significant and growing role across the world as an important vector of several pathogens including those that cause dengue and Chikungunya fevers [25]. Ecologically, Ae. albopictus is considered to be one of the worlds fastest-spreading invasive animal species [6]. While native to East Asia, it has recently colonized every continent except Antarctica (most recently reviewed by [5]), and its range is expected to grow in the future [2,7,8]. The impact of this range expansion on disease spread is difficult to predict [9,10], but it will likely pose additional threats to public health [5]. Consequently, there is an urgent need to develop effective strategies for controlling the reproduction and spread of Ae. albopictus [11]. One step toward managing the reproduction of Ae. albopictus is to investigate seminal fluid proteins (Sfps), which are proteins that males transfer to females during mating. Sfps in insects are crucially important for male reproductive success, and they modulate several aspects of female post-mating behavior and physiology [12,13]. In Ae. albopictus, receipt of Sfps bolsters egg development under poor blood feeding conditions [14], increases egg laying [15], and inhibits female remating [16,17]. Interestingly, some of these Sfp-induced effects can last throughout the life of the female, even when she receives a only a very small dose of Sfps [17]. Since Sfps modify female behavior so drastically, their identification and functional characterization may provide promising targets for the control of insects that transmit disease-causing organisms [1820]. Sfps have been identified for a number of insects, including Drosophila melanogaster [2123], medflies [24,25], and species of sand flies [26], honey bees [27], butterflies [28,29], flour beetles The highly invasive Asian tiger mosquito (Aedes albopictus) transmits several pathogens that cause disease in humans and other animals. Therefore, Ae. albopictus poses a large and growing threat to public health across the world. One step toward managing the reproduction and threat of this species is to determine factors that influence its reproductive biology. Seminal fluid proteins (Sfps) are transferred from male mosquitoes to females during mating, and receipt of Sfps changes female reproductive behavior and physiology. Here we report the identity of 198 Ae. albopictus Sfps. We discuss the potential roles and impacts of these Sfps on reproduction. In addition, we compare Ae. albopictus Sfps with proteins (including reported Sfps) from other species, including two other important mosquito vectors of pathogens that cause human diseases. Our results provide a foundation for future studies to investigate the roles of individual Sfps on Ae. albopictus reproduction. [30], and crickets [3134]. Sfps have recently been identified in two mosquito species, the malaria vector Anopheles gambiae [19,20,35] and the yellow fever mosquito Aedes aegyp (...truncated)