Investigating the evolution of animal gametes
Cellular and Molecular foundations of animal sperm and egg
All animals start their development through the fusion of two highly specialized gametes: a sperm and an egg. Despite their importance, little is known about their evolutionary origin. As the closest living relatives of animals, choanoflagellates are uniquely suited to investigate the ancestry of animal gametogenesis. During my postdoctoral research, I am using the model choanoflagellate Salpingoeca rosetta, which can produce anisogametes under certain environmental conditions, to better understand the cellular and molecular foundations of animal gametes.
The first animal (green circle) evolved from a now-extinct unicellular ancestor (green/magenta), shared with choanoflagellates (magenta). Somewhere along this evolutionary path, the ability to differentiate into sperm and egg cells emerged. Whether animal gametes arose from ancient sexual programs already present in the unicellular ancestor is unknown. Some choanoflagellates (e.g. Salpingoeca rosetta) can differentiate into morphologically distinct male and female gametes (anisogametes) under specific environmental conditions.
Garcia De Las Bayonas A., Gonzalez S., King N. An adhesion GPCR regulates cell adhesion and mating in the closest living relatives of metazoans. BioRxiv 2026.06.27.734982; doi: 10.64898/2026.06.27.734982. [link]
Mapping the GPCR Toolkit in Choanoflagellates
Receptor diversity in animals' closest relatives
G protein-coupled receptors (GPCRs) are central to animal biology, detecting signals ranging from light and hormones to neurotransmitters. They also constitute the largest class of drug targets in medicine. Yet how this signaling system evolved before the origin of animals remains unclear. Although GPCRs have been relatively well characterized in animals, far less is known about GPCR signaling in choanoflagellates, their closest living relatives. During my postdoctoral research, I am investigating the choanoflagellate GPCR repertoire using genomic and transcriptomic data from 23 choanoflagellate species. This work will provide a valuable resource for future comparative studies of GPCR biology and evolution.
1. Alain Garcia De Las Bayonas, Nicole King (2025) G-protein-coupled receptor diversity and evolution in the closest living relatives of metazoa eLife 14:RP107467.
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