RT Journal Article
SR Electronic
T1 Genomic Analysis of Hypoxia Inducible Factor Alpha Evolution in Ray-finned Fishes (Actinopterygii)
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.04.16.440203
DO 10.1101/2021.04.16.440203
A1 Ian K. Townley
A1 Bernard B. Rees
YR 2021
UL http://biorxiv.org/content/early/2021/04/18/2021.04.16.440203.abstract
AB Two rounds of genome duplication (GD) in the ancestor of vertebrates, followed by additional GD during the evolution of ray-finned fishes (Actinopterygii), expanded certain gene families, including those encoding the hypoxia inducible transcription factor (HIF). The present study analyzed Actinopterygian genomes for duplicates of HIFα, the subunit that confers oxygen-dependent gene regulation. In contrast to tetrapod vertebrates that retain three HIFα genes from the ancestral vertebrate GD, four HIFα forms were found in the genomes of primitive Actinopterygians (spotted gar and Asian arowana). All four forms have been retained in zebrafish and related species (Otocephala) and salmonids and their sister taxa (northern pike) but one of them (HIF4α) was lost during the evolution of more derived fishes (Neoteleostei). In addition, the current analyses confirm that Otocephala retain duplicates of HIF1α and HIF2α from the teleost-specific GD, provide new evidence of salmonid-specific duplicates of HIF1α, HIF2α, and HIF3α, and reveal a broad distribution of a truncated form of HIF2α in salmonids and Neoteleostei. This study delivers a comprehensive view of HIFα evolution in the ray-finned fishes, highlights the need for a consistent nomenclature, and suggests avenues for future research on this critical transcription factor.Competing Interest StatementThe authors have declared no competing interest.