Transcriptional Profiles of Mating-Responsive Genes from Testes and Male Accessory Glands of the Mediterranean Fruit Fly, Ceratitis capitata

Abstract

BackgroundInsect seminal fluid is a complex mixture of proteins, carbohydrates and lipids, produced in the male reproductive tract. This seminal fluid is transferred together with the spermatozoa during mating and induces post-mating changes in the female. Molecular characterization of seminal fluid proteins in the Mediterranean fruit fly, Ceratitis capitata, is limited, although studies suggest that some of these proteins are biologically active.Methodology/Principal FindingsWe report on the functional annotation of 5914 high quality expressed sequence tags (ESTs) from the testes and male accessory glands, to identify transcripts encoding putative secreted peptides that might elicit post-mating responses in females. The ESTs were assembled into 3344 contigs, of which over 33% produced no hits against the nr database, and thus may represent novel or rapidly evolving sequences. Extraction of the coding sequences resulted in a total of 3371 putative peptides. The annotated dataset is available as a hyperlinked spreadsheet. Four hundred peptides were identified with putative secretory activity, including odorant binding proteins, protease inhibitor domain-containing peptides, antigen 5 proteins, mucins, and immunity-related sequences. Quantitative RT-PCR-based analyses of a subset of putative secretory protein-encoding transcripts from accessory glands indicated changes in their abundance after one or more copulations when compared to virgin males of the same age. These changes in abundance, particularly evident after the third mating, may be related to the requirement to replenish proteins to be transferred to the female.Conclusions/SignificanceWe have developed the first large-scale dataset for novel studies on functions and processes associated with the reproductive biology of Ceratitis capitata. The identified genes may help study genome evolution, in light of the high adaptive potential of the medfly. In addition, studies of male recovery dynamics in terms of accessory gland gene expression profiles and correlated remating inhibition mechanisms may permit the improvement of pest management approaches.

Transcriptome analysis in Ceratitis capitata to unveil genes involved in ageing-maturation process

“…Five mssps have been characterized in the medfly (Katsoris et al, 1990;Thymianou et al, 1995). The synthesis of the mssps has been described to take place mainly during the first 5 days after adults' emergence (Thymianou et al, 1998;Scolari et al, 2012). Our data reveal that the main expression of these genes took place between the 5 and the 15 day after emergence, suggesting that male maturity in this medfly strain is reached later.…”

Drosophila reproduction: Molecules meet morphology

“…SFPs in disease-vectoring mosquitoes (23) and in economically important insects, such as flour beetles (24), honey bees (25), and Mediterranean fruit flies (26), also have been characterized, and their effects on female reproductive physiology have been documented. Probing postcopulatory reproductive processes in these species using micro-CT and CRISPER/CA9 can expand our understanding of reproduction in these pests and disease vectors and suggest new targets to control their reproduction.…”

Testis‐specific RNA‐Seq of Calligrapha (Chrysomelidae) as a transcriptomic resource for male‐biased gene inquiry in Coleoptera

“…These and other recent studies included the analysis of seminal proteins in Heliconius butterflies (Walters & Harrison , ), mating‐responsive genes in Ceratitis Mediterranean fruit flies (Scolari et al . ), X‐linked genes in stalk‐eyed Teleopsis flies (Reinhardt et al . ), spermatogenesis genes (Wei et al .…”

“…Recently, Oppenheim et al (2015) listed the handful of studies that have specifically examined the transcriptomes of male reproductive organs of nonmodel insects. These and other recent studies included the analysis of seminal proteins in Heliconius butterflies (Walters & Harrison 2010, mating-responsive genes in Ceratitis Mediterranean fruit flies (Scolari et al 2012), X-linked genes in stalk-eyed Teleopsis flies (Reinhardt et al 2014), spermatogenesis genes (Wei et al 2015) and testicular miRNAs (Tariq et al 2016) in Bactrocera fruit flies, novel transcripts in the paternal sex ratio chromosome of Nasonia jewel wasps (Akbari et al 2013), SSR development in Periplaneta American cockroach (Chen et al 2015), or a broad view of transcriptome architecture in the phlebotomine sand fly Lutzomyia (Azevedo et al 2012), the tsetse fly Glossina (Scolari et al 2016), Gryllus and Teleogryllus field crickets (Andres et al 2013;Bailey et al 2013), or again in Teleopsis (Baker et al 2012). To date, however, there are no similar studies in any representative of the huge Order Coleoptera.…”