Abstract
Increased understanding of the molecular components involved in reproduction may assist in understanding the evolutionary adaptations used by animals, including hermaphrodites, to produce offspring and retain a continuation of their lineage. In this study, we focus on the Mediterranean snail, Theba pisana, a hermaphroditic land snail that has become a highly invasive pest species within agricultural areas throughout the world. Our analysis of T. pisana CNS tissue has revealed gene transcripts encoding molluscan reproduction-associated proteins including APGWamide, gonadotropin-releasing hormone (GnRH) and an egg-laying hormone (ELH). ELH isoform 1 (ELH1) is known to be a potent reproductive peptide hormone involved in ovulation and egg-laying in some aquatic molluscs. Two other non-CNS ELH isoforms were also present in T. pisana (Tpi-ELH2 and Tpi-ELH3) within the snail dart sac and mucous glands. Bioactivity of a synthetic ELH1 on sexually mature T. pisana was confirmed through bioassay, with snails showing ELH1-induced egg-laying behaviours, including soil burrowing and oviposition. In summary, this study presents a detailed molecular analysis of reproductive neuropeptide genes in a land snail and provides a foundation for understanding ELH function.
Highlights
Snail reproduction is controlled by a tetra neural central nervous system (CNS) [1,2] that coordinates the timely release and action of potent neuropeptides
At 379 amino acids, and encoding twelve APGWamide peptides, Tpi-APGW1 was larger than the Haliotis asinina APGWamide precursor [31], and is approximately 29% larger than Tpi-APGW2. This variability was due to the inclusion of a single 111 amino acid insert in TpiAPGW1 compared with Tpi-APGW2, and comparative to other molluscs, this makes it the largest known molluscan APGWamide precursor identified to date
We have found that T. pisana does not contain a precursor with multiple egg-laying hormone (ELH), it does have an additional two ELH genes, the Tpi-ELH2 and Tpi-ELH3, which are expressed in non-neural tissues, as determined by tissue-specific Reverse Transcription-Polymerase Chain Reaction (RT-PCR)
Summary
Snail reproduction is controlled by a tetra neural central nervous system (CNS) [1,2] that coordinates the timely release and action of potent neuropeptides. There are several neuropeptides that have attracted particular research interest due to their conserved role in reproductive processes, including Ala-Pro-Gly-Try-amide (APGWamide), egg-laying hormone (ELH), and gonadotropin-releasing hormone (GnRH). In Lymnaea stagnalis, APGWamide is known to regulate male reproductive functions, such as controlling penis eversion and inhibition of spontaneous muscular contractions of smooth muscle in the vas deferens [4,5], as well as spermiation in the Donkey’s ear abalone (Haliotis asinina) [6]. In Aplysia, ELH regulates functions of the female reproductive system, namely those involved with ovulation and egg laying [1,15]. Injection of the CDCH into Lymnaea stimulates ovulation and egg mass formation [16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
