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

Abstract

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.

Synthesis, depletion and cell-type expression of a protein from the male accessory glands of the dengue vector mosquito Aedes aegypti

“…However, there are three transferred Ae. albopictus Sfps that have 68% identity with AAEL010824 over the entire length of the protein (Boes et al, 2014). This finding is interesting as Leahy (1965) showed that implantation of Ae.…”

“…Sequences from predicted Ae. albopictus proteins were obtained from Boes et al (2014). Sequences from predicted Ae.…”

Who’s Zooming Who? Seminal Fluids and Cryptic Female Choice in Diptera

“…There is ample evidence that, across a wide range of taxa, Sfps do tend to diverge more quickly on averge than non-Sfp genes (e.g., Aguadé 1998Aguadé , 1999Begun et al 2000;Swanson et al 2001;Haerty et al 2007;Almeida and DeSalle 2008;Mancini et al 2011;Wong et al 2012;Wong and Rundle 2013;Boes et al 2014). However, this pattern is consistent not only with CFC and sexually antagonistic coevolution, but also with male-male competition and other forms of selection such as host-pathogen interactions .…”

“…In some instances, both males and females produce the same proteins-transferred as Sfps in the case of the male. For example, Aedes albopictus males transfer the neuropeptide adipokinetic hormone-1 (AKH-1) to females during mating (Boes et al 2014). AKH-1 is also produced by female mosquitoes and mobilizes the release of carbohydrates from the fat body into the hemolymph in some species (Kaufmann and Brown 2008;Kaufmann et al 2009).…”

“…They argued for the importance of integrating evolutionary and physiological approaches in the study of Sfps (Eberhard and Cordero 1995). Since that time, many researchers have pursued such an integration through a variety of methods including investigating the mechanisms by which Sfps act in females (e.g., Heifetz and Wolfner 2004;Yang et al 2008;Yapici et al 2008;Häsemeyer et al 2009;Rogers et al 2009;Fricke et al 2013;Haussmann et al 2013;Rubinstein and Wolfner 2013;Heifetz et al 2014;Rezával et al 2014), testing for positive Darwinian selection on Sfps (e.g., Aguadé 1998Aguadé , 1999Begun et al 2000;Swanson et al 2001;Haerty et al 2007;Almeida and DeSalle 2008;Walters and Harrison 2010;Mancini et al 2011;Wong et al 2012;Wong and Rundle 2013;Boes et al 2014), comparing the rates of Sfp evolution across mating systems that differ in the strength of sexual selection (e.g., Walters and Harrison 2010), conducting experimental evolution studies (e.g., Wong and Rundle 2013), and testing how indicators of sperm competition affect Sfp production and allocation (e.g., Wigby et al 2009;Sirot et al 2011). Together, these studies provide a rich new resource for evaluating the potential for CFC to act on Sfps.…”