Functional assay of differentially expressed SFP genes

Background

Seminal fluid proteins (SFPs) are proteins in ejaculates, transferred to mating partners together with sperm. It has been well documented that SFPs play important roles in mediating healthy post-mating processes (e.g., inducing ovulation), and for exploiting mated females for the benefits of males (e.g., reducing re-mating rate of females). Aligned with these SFP functions, it has been revealed that males strategically use SFPs. For instance, it has been demonstrated that male D. melanogaster tailors the amount of sperm and SFPs independently, according to a sperm competition gradient (Hopkins et al. 2019).

It remains to be examined whether differential production of SFPs associates with their functions in L. stagnalis. Previous studies in this species showed that receiving the SFP LyAcp10 delays egg laying, and receiving LyAcp5 and/or LyAcp8b reduces sperm transfer in a subsequent mating (Koene et al. 2010; Nakadera et al. 2014). Our study also revealed that L. stagnalis increases SFP production when they have a mating partner, including LyAcp10 and LyAcp8b (Nakadera et al. 2019). Therefore, we expect that SFP composition from the snails with one or more mating partners are able to reduce egg laying and sperm transfer far more than SFPs from the ejaculate of snails without a mate. Combined with transcriptomic and proteomic data of SFPs from other on-going projects, functional assays of differentially-expressed SFPs will substantially contribute to reveal the complete picture of SFP expression in Lymnaea stagnalis.

Approaches

– Artificial injection
– Mating observation
– Measure reproductive performance (egg production, sperm transfer)
– Life history traits (growth, maturation)
– Statistics

Keywords

Sexual selection, sexual conflict, reproductive protein, functional assay, gene expression

Reference

Koene JM, Sloot W, Montagne-Wajer K, Cummins SF, Degnan BM, Smith JS, Nagle GT, Ter Maat A. 2010. Male accessory gland protein reduces egg laying in a simultaneous hermaphrodite. PLoS ONE 5:e10117.

Nakadera Y, Giannakara A, Ramm SA. 2019. Plastic expression of seminal fluid protein genes in a simultaneously hermaphroditic snail. Behavioral Ecology 30:904-913.

Nakadera Y, Swart EM, Hoffer JNA, den Boon O, Ellers J, Koene JM. 2014. Receipt of seminal fluid proteins causes reduction of male investment in a simultaneous hermaphrodite. Current Biology 24: 859–862.

Supervision

Dr. Joris M. Koene
E-mail: joris.koene@vu.nl

Dr. Yumi Nakadera
y.nakadera@vu.nl