Polyploidy plays an important role in evolution, providing a ‘backup’ genetic material and increasing
genetic novelty. However, polyploids have to adapt their cellular machinery to the instantaneous
doubling of chromosomes, in particular the segregation of chromosomes during meiosis, since
random crossovers between each copy may compromise regular chromosomal segregation.
Polyploidy in animals is rare and most polyploid animals reproduce asexually. The Amphibia is the
only exception among vertebrates with multiple independent sexualy reproducing polyploid
lineages, as in the Australian frog genus Neobatrachus. Our preliminary results comparing
nucleotide diversity and differentiation between the diploid N. pictus and the tetraploid N. sudellae
show that potentially selected genes in the tetraploid are enriched for microtubule motor activity
function. This suggests modifications of the homologous pairing process during meiosis.
To clarify the mechanism of meiotic adaptation in Neobatrachus, we will assemble genome of the
diploid N. pictus. The Neobatrachus reference genome will be only a third available genome for the
Order Anura and the first one for the Superfamily Hyloidea. By extending low coverage genome data
for the rest of the genus we will reconstruct its evolutionary history, and identify potentially
selected regions and adaptive changes in tetraploids compared to diploids. This will provide the first
description of adaptation mechanism to polyploidy in animals.