講題:  複製基因對於紅火蟻不同社會類型演化之影響


​講者: Dr. Silvia Fontana (方森婭 博士)

時間: 12/2 (三)10:40-12:10

地點: LS114于名振教室 ​

演講摘要:The  fire ant  Solenopsis invicta presents two social forms:  monogyne colonies, with only one queen,  and polygyne colonies, with multiple queens, regulated by a  ~20  Mb supergene with two variants called "Social  B (SB)"  and  "Social b (Sb)". The supergene includes ~600 genes linked together by a big inversion, which prevents recombination between the two variants. In monogyne colonies, all individuals carry only the SB allele, while in polygyne colonies, some individuals carry the Sb allele. Polygyne workers can distinguish from monogyne (SB/SB) and polygyne (SB/Sb) queens based on odor cues, rejecting monogyne queens from the colony. This study characterizes genetic duplications on the non-recombining social supergene. Extensive acquisition of gene duplicates was found in the Sb genome, with some likely involved in polygyne-related phenotypes. A total of 260 genes have copy number differences between SB and Sb, of which 239 have greater copy number in Sb. Genes duplicated in Sb encompass various functions: putative enzymes responsible for cuticular hydrocarbons (CHCs) and juvenile hormone synthesis, transcription factors, histones, and kinases. Candidate duplications potentially responsible for different CHC profiles in SB and Sb queens were identified. They include a desaturase and an elongase; both potentially responsible for differential queen odor and likely beneficial for polygyne ants. These genes seem to have translocated into the supergene from other chromosomes and proliferated by multiple duplication events. Overall, the results suggest that gene duplications may be an important factor leading to monogyne and polygyne ant societies.