Nature Communications: The genetic mechanism by which flat-bellied wasps maintain genome stability and rapid venom evolution

On October 27, 2022, the team of Professor Ye Gongyin from the College of Agriculture and Biotechnology of Zhejiang University, together with the Institute of Plant Protection of the Guangdong Academy of Agricultural Sciences, and other teams published a speech in Nature Communications The research paper "Genomic signatures associated with maintenance of genome stability and venom turnover in two parasitoid wasps" reveals the genomic characteristics
of parasitic wasps to maintain genome stability and rapid venom evolution 。 At the same time, the paper also reported the high-quality genomic information of two types of flat-bellied wasps, which provided an important genetic information resource
for biological control research.

Parasitic wasps are a class of insects with extremely rich biodiversity and are ideal models
for studying evolutionary biology.
The comparative genomics study of them is of great significance
to uncover the secrets of the evolution of various magical traits and enrich people's understanding of the evolution of species.
The flat-bellied wasp is an excellent class of egg parasitic wasps, and it is also one of the natural enemies of parasitic natural enemies that have mature large-scale breeding technology and field release technology, and have been successfully applied to pest control, and have remarkable
effects in the control of fruit tree bugs.
However, the genetic level of its effective pest control has been significantly insufficiently
understood to date.

Through gene genome sequencing and assembly, the team determined that the genome size of Anastatus japonicus and A.
fulloi of the Japanese flat-bellied bee Anastatus japonicus and A.
fulloi is about 950 Mb, which is the genome size of most known hymenoptera 2~4 times
.
Further research showed that the large genomic profile of flat-bellied wasps was associated
with recent LTR transposon expansion.
At the same time, it was noted that a large number of intact transposable elements were present in the bee's genome, which may mean that these elements are still transposable and pose a threat
to the stability of the genome.
Exploring the evolutionary characteristics of the bee's genome in response to these potential threats to genome stability, it was found that the Piwi gene associated with piRNA was amplified in large numbers and widely expressed
at various developmental stages and among tissues.
In addition, combined with small RNA sequencing data, the inhibitory effect
of piRNA on transposons was further confirmed.
At the same time, combined with venom multi-omics data, the rapid evolution mechanism of venom genes of two flat-bellied wasps was studied, and it was found that gene selection (co-option) and neofunctionalization after gene replication were found and other evolutionary models have jointly shaped the pattern of rapid evolution of flat-bellied bee venom, in which gene selection plays a major role
.
In addition, the study also constructs a regulatory network of venom genes, finds a large number of non-venom functional genes co-expressed with venom genes, and identifies that such non-venom genes may also play an important role in the rapid evolution of venom (Figure 1).

In conclusion, this study demonstrates the evolutionary strategy of the parasitic bee genome in response to sudden transposon outbreaks, which is helpful for further study of the molecular mechanism that maintains genome stability and is of great significance
for in-depth understanding of genome size evolution.
At the same time, the discovery of the rapid evolution of parasitic bee venom has improved the evolutionary model of venom genes, which is of great value
for in-depth understanding of the production of new gene functions.

Dr.
Xinhai Ye and Dr.
Yi Yang of Zhejiang University and Dr.
Can Zhao, Institute of Plant Protection, Guangdong Academy of Agricultural Sciences are the co-first authors, and Professor Gongyin Ye of the Institute of Entomological Sciences, Zhejiang University, and researcher Li Dunsong, Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, are the corresponding authors
of this paper.
Professor Wu Fei, School of Computer Science/Zhejiang University, Shanghai Institute for Advanced Study, Zhejiang University, Associate Professor Fang Qi, Dr.
Xiao Shan, Dr.
Xiong Shijiao, Dr.
Zhao Xianxin, Dr.
Sun Yu of the University of Rochester, and Xu Hongxing, researcher of Zhejiang Academy of Agricultural Sciences, participated in the study
.
The research work has been supported
by the National Natural Science Foundation of China Key Program, the National Natural Science Foundation of China Youth Program, the National Litchi Longan Industrial Technology System Project, and the China Postdoctoral Fund.

Fig.
1 Evolution of flat-bellied bee venom-related network modules

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