Asymmetric Fitness of Second-Generation Interspecific Hybrids Between Ciona robusta and Ciona intestinalis
Year: 2020
Type: article
Abstract: Reproductive isolation is central to speciation, but interspecific crosses between two closely related species can produce viable and fertile hybrids. Two different species in the tunicate genus Ciona , Ciona robusta and Ciona intestinalis can produce hybrids. However, wild sympatric populations display limited gene flow, suggesting the existence of obstacles to interspecific reproduction that remain unknown. Here, we took advantage of a closed inland culture system to cross C. robusta with C. intestinalis and established F1 and F2 hybrids. We monitored post-embryonic development, survival, and sexual maturation to further probe the physiological mechanisms underlying reproductive isolation. Partial viability of first and second generation hybrids indicated that both pre- and postzygotic mechanisms contributed to genomic incompatibilities in hybrids. Asymmetrical second generation inviability and infertility suggested that interspecific genomic incompatibilities involved interactions between the maternal, zygotic and mitochondrial genomes during development. This study paves the way to quantitative genetic approaches to study the mechanisms underlying genomic incompatibilities and other complex traits in the genome-enabled Ciona model.
Source: G3 Genes Genomes Genetics
Institution: New York University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,709
OpenAlex ID: W3033662215