Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Áki Jarl Láruson (1), Maria Akopyan (2), Nina Overgaard Therkildsen (2)
Starfsvettvangur / Affiliations: 1. Marine & Freshwater Research Institute, Fornbúðir 5, 220 Hafnarfjörður, Iceland 2. Cornell University, Department of Natural Resources & the Environment, 208 Fernow Hall, Ithaca, NY 14853
Kynnir / Presenter: Áki Jarl Láruson
The neotropical silversides (genus Menidia) are a group of small Atheriniforme fish that range across the Caribbean and West Atlantic. Remarkable diversity within Menidia has been observed in terms of habitat preference (freshwater, euryhaline, marine) and reproductive strategy (sexual & asexual). Recent genome sequencing of the Atlantic silverside (M. menidia) revealed several large chromosomal inversions that segregate across different populations along the Eastern US coast. These inversions exhibit substantially elevated sequence divergence levels across the species range, compared to sequences outside the inversions. A few sequences even show divergence levels comparable to the average divergence seen between M. menidia and the congeners M. beryllina & M. penisula, from which M. menidia diverged approximately 11 million years ago. By sampling and crossing individuals from two distinct populations, from Georgia and New York, a cohort of hybrid individuals was produced. Assessing the number of de novo variants present in the hybrid families gives a potentially very accurate per generation mutation rate, and was used to estimate when the chromosomal inversions originated, as well as reconstruct the historical demography of the two M. menidia populations fixed for opposite orientations of several inversions.