Mitochondrial phylogenomics reveal the origin and adaptive evolution of the deep-sea caridean shrimps(Decapoda:Caridea)

摘要

The deep-sea is considered as the most extensive ecosystem on the Earth.It is meaningful for elucidating the life origins by exploring the origin and adaptive genetic mechanisms of the large deepsea organisms.Caridean shrimps have colonized and successfully adapted to deep-sea environments.They provide an ideal model to analyze the origin and adaptive evolution of modern deep-sea fauna.Here,we conducted the phylogenetic analyses of mitocho ndrial genomes(mitogenomes)from carideans,including 11 newly sequences reported in this investigation to explore the habitat origins,divergence times,and adaptive evolution of deep-sea(seamounts and hydrothermal vents)caridean shrimps.The results showed that the species of deep-sea Caridea formed a monophyletic group.Phylogenetic analysis supported that the deepsea caridean shrimps may originated from shallow sea.The hydrothermal vents alvinocaridid shrimps and Lebbeus shinkaiae from Thoridae underwent a second range expansion from seamounts to vent ecosystems.Estimates of divergence time showed that the caridean shrimps invaded into deep-sea at 147.75 Ma.The divergence of most of the modern seamount and hydrothermal vent species are in the late Cretaceous/early Tertiary.This may associate with the geological events of the Western Pacific,the climate change,and the global deep-water anoxic/dysoxic events during this period.Twenty-two potentially important adaptive residues were detected in the deep-sea shrimp lineage,which were located in atp6,atp8,cox1,cox3,cytb,nad2,nad4 l,and nad5.This investigation adds our understanding of the evolutionary history of deep-sea caridean shrimps,and provides insights into the mitochondrial genetic basis of deep-sea adaptation in this group.