Loci Associated with Negative Heterosis for Viability and Meat Productivity in Interspecific Sheep Hybrids

SIMPLE SUMMARY: One of the main aims of selection is enhancing the economically important traits of animals and plants. Crossbreeding is one of the common ways to improve the economically important traits. Usually, different species of one genus are used for crossbreeding. The use of different closely related species is known as hybridization. It is expected that hybrids will have advantages over their parents in terms of economic productivity due to the effect known as heterosis. However, the phenomenon of negative heterosis exists and can induce negative impacts on different important traits, such as viability, reproductivity, productivity, etc. The exact biological mechanisms of negative heterosis remain unknown. In this study, we aimed to determine the genetic factors associated with negative heterosis in interspecific hybrids between domestic sheep (Ovis aries) and argali (Ovis ammon). We discovered one novel locus associated with viability and two novel loci associated with meat productivity. For loci associated with meat productivity, we demonstrated the effect of negative heterosis. These results may help to understand one of the possible genetic mechanisms of negative heterosis. ABSTRACT: Negative heterosis can occur on different economically important traits, but the exact biological mechanisms of this phenomenon are still unknown. The present study focuses on determining the genetic factors associated with negative heterosis in interspecific hybrids between domestic sheep (Ovis aries) and argali (Ovis ammon). One locus (rs417431015) associated with viability and two loci (rs413302370, rs402808951) associated with meat productivity were identified. One gene (ARAP2) was prioritized for viability and three for meat productivity (PDE2A, ARAP1, and PCDH15). The loci associated with meat productivity were demonstrated to fit the overdominant inheritance model and could potentially be involved int negative heterosis mechanisms.