TY - JOUR

T1 - Whole-genomes from the extinct Xerces Blue butterfly can help identify declining insect species

AU - de-Dios, Toni

AU - Fontsere, Claudia

AU - Renom, Pere

AU - Stiller, Josefin

AU - Llovera, Laia

AU - Uliano-Silva, Marcela

AU - Sánchez-Gracia, Alejandro

AU - Wright, Charlotte

AU - Lizano, Esther

AU - Caballero, Berta

AU - Navarro, Arcadi

AU - Civit, Sergi

AU - Robbins, Robert K.

AU - Blaxter, Mark

AU - Marquès-Bonet, Tomàs

AU - Vila, Roger

AU - Lalueza-Fox, Carles

PY - 2023

Y1 - 2023

N2 - The Xerces Blue (Glaucopsyche xerces) is considered to be the first butterfly to become extinct at global scale in historical times. It was notable for its chalky lavender wings with conspicuous white spots on the ventral wings. The last individuals were collected in their restricted habitat, in the dunes near the Presidio military base in San Francisco, in 1941. We sequenced the genomes of four 80 to 100-year-old Xerces Blue, and seven historical and one modern specimens of its closest relative, the Silvery Blue (G. lygdamus). We compared these to a novel annotated genome of the Green-Underside Blue (G. alexis). Phylogenetic relationships inferred from complete mitochondrial genomes indicate that Xerces Blue was a distinct species that diverged from the Silvery Blue lineage at least 850,000 years ago. Using nuclear genomes, both species experienced population growth during the Eemian interglacial period, but the Xerces Blue decreased to a very low effective population size subsequently, a trend opposite to that observed in the Silvery Blue. Runs of homozygosity and deleterious load in the Xerces Blue were significantly greater than in the Silvery Blue, suggesting a higher incidence of inbreeding. These signals of population decline observed in Xerces Blue could be used to identify and monitor other insects threatened by human activities, whose extinction patterns are still not well known.

AB - The Xerces Blue (Glaucopsyche xerces) is considered to be the first butterfly to become extinct at global scale in historical times. It was notable for its chalky lavender wings with conspicuous white spots on the ventral wings. The last individuals were collected in their restricted habitat, in the dunes near the Presidio military base in San Francisco, in 1941. We sequenced the genomes of four 80 to 100-year-old Xerces Blue, and seven historical and one modern specimens of its closest relative, the Silvery Blue (G. lygdamus). We compared these to a novel annotated genome of the Green-Underside Blue (G. alexis). Phylogenetic relationships inferred from complete mitochondrial genomes indicate that Xerces Blue was a distinct species that diverged from the Silvery Blue lineage at least 850,000 years ago. Using nuclear genomes, both species experienced population growth during the Eemian interglacial period, but the Xerces Blue decreased to a very low effective population size subsequently, a trend opposite to that observed in the Silvery Blue. Runs of homozygosity and deleterious load in the Xerces Blue were significantly greater than in the Silvery Blue, suggesting a higher incidence of inbreeding. These signals of population decline observed in Xerces Blue could be used to identify and monitor other insects threatened by human activities, whose extinction patterns are still not well known.

U2 - 10.7554/elife.87928.1

DO - 10.7554/elife.87928.1

M3 - Journal article

JO - eLife

JF - eLife

SN - 2050-084X

ER -