Searching for the molecular mechanisms underlying spiny lobsters sex determination and development

Over the past four years, a collaboration between the University and Tasmania (Utas) and the University of the Sunshine Coast (USC) in Australia has focused on gaining a better understanding of the molecular mechanisms underlying spiny lobster sex determination and larval development. The collaboration is underpinned by expertise in larval biology at Utas and genomics research at USC. For the first time in a spiny lobster species, we identified the androgenic gland and its putative hormone, which is key for regulating crustacean masculinity. We also characterised the receptor and additional components in the endocrine pathway of the insulin-like androgenic gland hormone. Most recently in Sagmariasus verreauxi, we identified the first invertebrate sex-linked (Y-linked) Dmrt gene and quantified expression during embryogenesis to describe the sex determination period. We are now developing biotechnologies to establish sterile monosex populations, which could benefit growth, behavior, and biosecurity in aquaculture. Developmental research has focused on the key transitional period of metamorphosis. Where, when, and why metamorphosis occurs are important factors affecting recruitment success and, in the context of aquaculture, metamorphosis presents a critical bottleneck due to stage-specific sensitivities. Spiny lobster also provide a valuable crustacean model due to the transparent larvae in which timing of metamorphosis can be accurately predicted. Our research shows that the phyllosoma-puerulus metamorphic transition in S. verreauxi is accompanied by vast transcriptomic changes and that genes previously identified as regulating metamorphosis in other crustaceans do not change during the metamorphic transition. Future research aims to utilize physiological assays, combined with transcriptomics, comparative bioinformatics, in situ hybridization, immunohistochemistry, and in vivo assays to better elucidate the pathways and discover the key factors that regulate lobster metamorphosis.