Adaptation of Fig Wasps (Agaodinae) to Their Host Revealed by Large-Scale Transcriptomic Data
by
, and
Lianfu Chen
1,2, 
Simon T. Segar
3,
Bhanumas Chantarasuwan
4,
Da-Mien Wong
1,
Rong Wang
4,
Xiaoyong Chen
5,* and
Hui Yu
1,2,* 1
Key Laboratory of Plant Resource Conservation and Sustainable Utilization, South China Botanical Garden, The Chinese Academy of Sciences, Guangzhou 510650, China
2
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
3
Department of Crop and Environment Sciences, Harper Adams University, Newport, Shropshire TF10 8NB, UK
4
Thailand Natural History Museum, National Science Museum, PtthumThani 12120, Thailand
5
School of Ecological and Environmental Sciences, Tiantong National Station for Forest Ecosystem Research, East China Normal University, Shanghai 200241, China
*
Authors to whom correspondence should be addressed.
Insects 2021, 12(9), 815; https://doi.org/10.3390/insects12090815
Submission received: 1 May 2021
/
Revised: 11 August 2021
/
Accepted: 8 September 2021
/
Published: 11 September 2021
Simple Summary
Research on fig wasps has made a considerable contribution to the understanding of insect–plant interactions. However, the molecular mechanisms underlying fig wasp host specificity are poorly understood. This study reports on a relatively large-scale transcriptomic dataset of 25 fig wasp species. We outline potential genetic mechanisms underlying the specific host adaptation by investigating changes in a gene family, in evolutionary rates, and in genes under positive selection. The transcriptome datasets reported here (1) provide new insights into the evolutionary diversification and host specificity of fig wasps and (2) contribute to a growing dataset on fig wasp genomics.
Abstract
Figs and fig wasps are highly species-specific and comprise a model system for studying co-evolution and co-speciation. The evolutionary relationships and molecular adaptations of fig wasps to their fig hosts are poorly understood, and this is in part due to limited sequence data. Here, we present large-scale transcriptomic datasets of 25 fig wasp species with the aim of uncovering the genetic basis for host specificity. Our phylogenetic results support the monophyly of all genera associated with dioecious figs, and two genera associated with monoecious figs, Eupristina and Platyscapa, were revealed to be close relatives. We identified gene loss and gain, potentially rapidly evolving genes, and genes under positive selection. Potentially functional changes were documented and we hypothesize as to how these may determine host specificity. Overall, our study provides new insights into the evolutionary diversification of fig wasps and contributes to our understanding of adaptation in this group.
Keywords:
Agaonidae; gene families; pollination ecology; specific mutualism; speciation
