Characterization of reproductive proteins in the Mexican fruit fly points towards the evolution of novel functions

Abstract

Seminal fluid proteins (Sfps) modify female phenotypes and have wide-ranging evolutionary implications on fitness in many insects. However, in the Mexican fruit fly, Anastrepha ludens , a highly destructive agricultural pest, the functions of Sfps are still largely unknown. To gain insights into female phenotypes regulated by Sfps, we used nano-liquid chromatography mass spectrometry to conduct a proteomic analysis of the soluble proteins from reproductive organs of A. ludens . The proteins predicted to be transferred from males to females during copulation were 100 proteins from the accessory glands, 69 from the testes and 20 from the ejaculatory bulb, resulting in 141 unique proteins after accounting for redundancies from multiple tissues. These 141 included orthologues to Drosophila melanogaster proteins involved mainly in oogenesis, spermatogenesis, immune response, lifespan and fecundity. In particular, we found one protein associated with female olfactory response to repellent stimuli (Scribble), and two related to memory formation (aPKC and Shibire). Together, these results raise the possibility that A. ludens Sfps could play a role in regulating female olfactory responses and memory formation and could be indicative of novel evolutionary functions in this important agricultural pest.

Behavioural and Electrophysiological Response of Anastrepha fraterculus (Diptera: Tephritidae) to a γ-Lactone Synthetic Semiochemical

“…Specifically, gene expression decreased after mating in female flies, showing that olfactory responses to sexual signals are switched off very rapidly after mating. Interestingly, this expression may be correlated with substances present in the male ejaculate, as was found for A. ludens [ 44 ]. Here, the greater antenna responsiveness of immature A. fraterculus could be related to greater gene expression of receptors involved in olfactory response to sexual signals.…”

Postcopulatory Behavior of Tephritid Flies

“…Transcriptomic and proteomic characterizations of the male reproductive tissues and or ejaculate have revealed important genes and proteins in the MAGs and testes (34,39,62,131,145). However, only a few studies have determined whether these molecules are transferred to females.…”

On the Role of Seminal Fluid Protein and Nucleic Acid Content in Paternal Epigenetic Inheritance

“…In D. melanogaster , a few Sfcs of interest were also detected on the surface of eggs [ 185 ]. It is also known that Sfcs penetrate the ovaries and are involved in egg development in some species [ 150 , 152 , 186 , 187 ]. The direct contact of Sfcs with the egg may potentially cause epigenetic changes within the egg, considering its known role in the potential mechanisms used in altering sperm epigenetics described above.…”