Genome Biol Evol. 2022 May 7:evac067. doi: 10.1093/gbe/evac067. Online ahead of print.
ABSTRACT
The Balearic shearwater (Puffinus mauretanicus) is the most threatened seabird in Europe and member of the most speciose group of pelagic seabirds, the order Procellariiformes, which exhibit extreme adaptations to a pelagic lifestyle. The fossil record suggests that human colonization of the Balearic Islands resulted in a sharp decrease of the Balearic shearwater population size. Currently, populations continue to be decimated mainly due to predation by introduced mammals and bycatch in longline fisheries, and some studies predict their extinction by 2070. Here, we generated the first high-quality reference genome for the species, with a completeness amongst the highest across available avian species, using a combination of short and long reads. We used this reference genome to study critical aspects relevant to the conservation status of the Balearic shearwater and to gain insights into the adaptation to a pelagic lifestyle of the order Procellariiformes. We detected relatively high levels of genome-wide heterozygosity in the Balearic shearwater despite its reduced population size. However, the reconstruction of its historical demography uncovered an abrupt population decline potentially linked to a reduction of the neritic zone during the Penultimate Glacial Period (∼194-135 kya). Comparative genomics analyses uncover a set of candidate genes that may have played an important role into the adaptation to a pelagic lifestyle of Procellariiformes, including those for the enhancement of fishing capabilities, night vision and the development of natriuresis. The reference genome obtained will be the keystone for future developments of genetic tools in conservation efforts for this Critically Endangered species.
PMID:35524941 | DOI:10.1093/gbe/evac067
