TY - JOUR
T1 - Primates, Lice and Bacteria
T2 - Speciation and Genome Evolution in the Symbionts of Hominid Lice
AU - Boyd, Bret M.
AU - Allen, Julie M.
AU - Nguyen, Nam Phuong
AU - Vachaspati, Pranjal
AU - Quicksall, Zachary S.
AU - Warnow, Tandy
AU - Mugisha, Lawrence
AU - Johnson, Kevin P.
AU - Reed, David L.
N1 - WOS:000402754400017
PY - 2017/7/1
Y1 - 2017/7/1
N2 - Insects with restricted diets rely on symbiotic bacteria to provide essential metabolites missing in their diet. The bloodsucking lice are obligate, host-specific parasites of mammals and are themselves host to symbiotic bacteria. In human lice, these bacterial symbionts supply the lice with B-vitamins. Here, we sequenced the genomes of symbiotic and heritable bacterial of human, chimpanzee, gorilla, and monkey lice and used phylogenomics to investigate their evolutionary relationships. We find that these symbionts have a phylogenetic history reflecting the louse phylogeny, a finding contrary to previous reports of symbiont replacement. Examination of the highly reduced symbiont genomes (0.53–0.57 Mb) reveals much of the genomes are dedicated to vitamin synthesis. This is unchanged in the smallest symbiont genome and one that appears to have been reorganized. Specifically, symbionts from human lice, chimpanzee lice, and gorilla lice carry a small plasmid that encodes synthesis of vitamin B5, a vitamin critical to the bacteria-louse symbiosis. This plasmid is absent in an old world monkey louse symbiont, where this pathway is on its primary chromosome. This suggests the unique genomic configuration brought about by the plasmid is not essential for symbiosis, but once obtained, it has persisted for up to 25 My. We also find evidence that human, chimpanzee, and gorilla louse endosymbionts have lost a pathway for synthesis of vitamin B1, whereas the monkey louse symbiont has retained this pathway. It is unclear whether these changes are adaptive, but they may point to evolutionary responses of louse symbionts to shifts in primate biology.
AB - Insects with restricted diets rely on symbiotic bacteria to provide essential metabolites missing in their diet. The bloodsucking lice are obligate, host-specific parasites of mammals and are themselves host to symbiotic bacteria. In human lice, these bacterial symbionts supply the lice with B-vitamins. Here, we sequenced the genomes of symbiotic and heritable bacterial of human, chimpanzee, gorilla, and monkey lice and used phylogenomics to investigate their evolutionary relationships. We find that these symbionts have a phylogenetic history reflecting the louse phylogeny, a finding contrary to previous reports of symbiont replacement. Examination of the highly reduced symbiont genomes (0.53–0.57 Mb) reveals much of the genomes are dedicated to vitamin synthesis. This is unchanged in the smallest symbiont genome and one that appears to have been reorganized. Specifically, symbionts from human lice, chimpanzee lice, and gorilla lice carry a small plasmid that encodes synthesis of vitamin B5, a vitamin critical to the bacteria-louse symbiosis. This plasmid is absent in an old world monkey louse symbiont, where this pathway is on its primary chromosome. This suggests the unique genomic configuration brought about by the plasmid is not essential for symbiosis, but once obtained, it has persisted for up to 25 My. We also find evidence that human, chimpanzee, and gorilla louse endosymbionts have lost a pathway for synthesis of vitamin B1, whereas the monkey louse symbiont has retained this pathway. It is unclear whether these changes are adaptive, but they may point to evolutionary responses of louse symbionts to shifts in primate biology.
KW - Anoplura
KW - Ca. Riesia
KW - endosymbiont replacement
KW - pantothenate
KW - plasmid
KW - thiamin
UR - http://www.scopus.com/inward/record.url?scp=85032495966&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85032495966&partnerID=8YFLogxK
U2 - 10.1093/MOLBEV/MSX117
DO - 10.1093/MOLBEV/MSX117
M3 - Article
C2 - 28419279
AN - SCOPUS:85032495966
SN - 0737-4038
VL - 34
SP - 1743
EP - 1757
JO - Molecular biology and evolution
JF - Molecular biology and evolution
IS - 7
ER -