TY - JOUR
T1 - Obligate mutualism within a host drives the extreme specialization of a fig wasp genome
AU - Xiao, Jin-Hua
AU - Yue, Zhen
AU - Jia, Ling-Yi
AU - Yang, Xin-Hua
AU - Niu, Li-Hua
AU - Wang, Zhuo
AU - Zhang, Peng
AU - Sun, Bao-Fa
AU - He, Shun-Min
AU - Li, Zi
AU - Xiong, Tuan-Lin
AU - Xin, Wen
AU - Gu, Hai-Feng
AU - Wang, Bo
AU - Werren, John H.
AU - Murphy, Robert W.
AU - Wheeler, David
AU - Niu, Li-Ming
AU - Ma, Guang-Chang
AU - Cook, James M.
PY - 2013
Y1 - 2013
N2 - Background: Fig pollinating wasps form obligate symbioses with their fig hosts. This mutualism arose approximately 75 million years ago. Unlike many other intimate symbioses, which involve vertical transmission of symbionts to host offspring, female fig wasps fly great distances to transfer horizontally between hosts. In contrast, male wasps are wingless and cannot disperse. Symbionts that keep intimate contact with their hosts often show genome reduction, but it is not clear if the wide dispersal of female fig wasps will counteract this general tendency. We sequenced the genome of the fig wasp Ceratosolen solmsi to address this question. Results: The genome size of the fig wasp C. solmsi is typical of insects, but has undergone dramatic reductions of gene families involved in environmental sensing and detoxification. The streamlined chemosensory ability reflects the overwhelming importance of females finding trees of their only host species, Ficus hispida, during their fleeting adult lives. Despite long-distance dispersal, little need exists for detoxification or environmental protection because fig wasps spend nearly all of their lives inside a largely benign host. Analyses of transcriptomes in females and males at four key life stages reveal that the extreme anatomical sexual dimorphism of fig wasps may result from a strong bias in sex-differential gene expression. Conclusions: Our comparison of the C. solmsi genome with other insects provides new insights into the evolution of obligate mutualism. The draft genome of the fig wasp, and transcriptomic comparisons between both sexes at four different life stages, provide insights into the molecular basis for the extreme anatomical sexual dimorphism of this species.
AB - Background: Fig pollinating wasps form obligate symbioses with their fig hosts. This mutualism arose approximately 75 million years ago. Unlike many other intimate symbioses, which involve vertical transmission of symbionts to host offspring, female fig wasps fly great distances to transfer horizontally between hosts. In contrast, male wasps are wingless and cannot disperse. Symbionts that keep intimate contact with their hosts often show genome reduction, but it is not clear if the wide dispersal of female fig wasps will counteract this general tendency. We sequenced the genome of the fig wasp Ceratosolen solmsi to address this question. Results: The genome size of the fig wasp C. solmsi is typical of insects, but has undergone dramatic reductions of gene families involved in environmental sensing and detoxification. The streamlined chemosensory ability reflects the overwhelming importance of females finding trees of their only host species, Ficus hispida, during their fleeting adult lives. Despite long-distance dispersal, little need exists for detoxification or environmental protection because fig wasps spend nearly all of their lives inside a largely benign host. Analyses of transcriptomes in females and males at four key life stages reveal that the extreme anatomical sexual dimorphism of fig wasps may result from a strong bias in sex-differential gene expression. Conclusions: Our comparison of the C. solmsi genome with other insects provides new insights into the evolution of obligate mutualism. The draft genome of the fig wasp, and transcriptomic comparisons between both sexes at four different life stages, provide insights into the molecular basis for the extreme anatomical sexual dimorphism of this species.
UR - http://handle.uws.edu.au:8081/1959.7/541895
UR - http://genomebiology.com/2013/14/12/R141
U2 - 10.1186/gb-2013-14-12-r141
DO - 10.1186/gb-2013-14-12-r141
M3 - Article
SN - 1474-7596
VL - 14
JO - Genome Biology
JF - Genome Biology
IS - 12
M1 - R141
ER -