Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E17
Höfundar / Authors: Quentin Horta-Lacueva (1), Lieke Ponsioen (1), Zophonías Jónsson (1), Kalina Kapralova (1)
Starfsvettvangur / Affiliations: (1) Háskóli Íslands
Kynnir / Presenter: Quentin Horta-Lacueva
Hybrid unviability is a powerful driver of reproductive isolation between populations evolving in contrasting environments. However, the genetic mechanisms underlying hybrid unviability are poorly understood. We investigated how heritable differences in skull morphology (a major agent of adaptive diversification in vertebrates) evolved between early diverging populations, what is their impact on the development of hybrids, and what are their molecular origins. We focused on the planktivorous (PL) and the small benthic (SB) Arctic charr of lake Thingvallavatn (Salvelinus alpinus), two morphs that have rapidly diverged towards pelagic and benthic feeding habitats, respectively. By conducting common garden experiments, we observed consistent differences between PL and SB charr across morphology and gene expression. The PL and SB embryos developed oral jaw morphologies with contrasting mechanical properties corresponding to the respective benthic vs. pelagic feeding modes of their respective parents. These findings were supported by differentially expressed candidate genes shaping the mechanical properties of the lower jaw. Finally, the hybrids between PL and SB charr exhibited a complex phenotype (intermediate, but less variable jaw morphology) and a unique pattern of gene expression related to nonadditive mechanisms of inheritance. These results imply that reproductive isolation may occur through the development of numerous, not necessarily intermediate traits in hybrids.