Insect Seminal Fluid Proteins: Identification and Function

Abstract

Seminal fluid proteins (SFPs) produced in reproductive tract tissues of male insects and transferred to females during mating induce numerous physiological and behavioral post-mating changes in females. These changes include decreasing receptivity to re-mating, affecting sperm storage parameters, increasing egg production, modulating sperm competition, feeding behaviors, and mating plug formation. In addition, SFPs also have anti-microbial functions and induce expression of anti-microbial peptides in at least some insects. Here, we review recent identification of insect SFPs and discuss the multiple roles these proteins play in the post-mating processes of female insects.

Morphological and morphometrical assessment of spermathecae of Aedes aegypti females

“…In addition, relative to virgin females, inseminated females have increased egg development and oviposition rates. These changes in inseminated females appear to be induced by molecules produced in male accessory glands and transferred to the female during mating as suggested by Avila et al (2010) and recently confirmed for An. gambiae (Thailayil et al 2011).…”

“…During copulation, the male deposits a mixture of sperm and accessory gland secretion in the female's bursa copulatrix, causing the female to become unreceptive to other males. Male seminal fluid proteins have been shown to influence female reproductive and feeding behaviours in many insects (reviewed in Gillot 2003, Avila et al 2010). In addition, relative to virgin females, inseminated females have increased egg development and oviposition rates.…”

The consequences of genetic variation in sex peptide expression levels for egg laying and retention in females

“…For female insects, mating often induces large transcriptional, physiological and behavioural changes that are often triggered by components of male seminal fluid (Avila et al, 2011). These changes and the molecules that cause them have been studied in detail in Drosophila melanogaster (Findlay et al, 2008).…”

The ejaculatory biology of leafcutter ants

“…We hypothesize that AG secretion might activate sperm to facilitate transfer to the queen's spermatheca (Poiani, 2006;Smith and Stanfield, 2012). AG secretion could also be transferred first to interact with the female environment before the arrival of sperm, for example to eliminate traces of microbial pathogens that might reside there, as seminal fluid has been shown to contain antimicrobial proteins in a number of insects and mammals (Avila et al, 2011;Baer et al, 2009b;Poiani, 2006). In addition, AG secretion could form a temporary barrier between sperm and ejaculates of rival males already present in the reproductive tract of the queen, to delay potential harmful effects.…”