Minifish as an Emerging Model for Vertebrate Genome Organization and Evolution

Paedocypris is a newly described minifish genus endemic to Southeast Asia. Minifish features the smallest adult vertebrate size, small fragmentary habitats and truncated development. Recently, we have revealed that minifish has also rapid chromosome diversification and the smallest known vertebrate genome (~315 Mb). Intriguingly, minifish mtDNA has compromised DNA replication and abundance of the so-called minifish repeat sequence in the D-loop. Furthermore, minifish shows extensive genetic variation within and between individuals of one and the same population as evidenced by variable mtDNA sizes. Embryological observations reveal rapid and truncated embryogenesis. Light and electron microscopic examinations reveal that both simplicity and complexity operate in the minifish body plan. These unusual characteristics make minifish as emerging unique lower vertebrate model to study several fundamental processes and issues including vertebrate genome organization and evolution, rapid speciation and the evolution of vertebrate development program. Effort has been initiated to sequence and analyze the minifish genome. This talk will present an overview on minifish biology and genome biology.