Genome Scan for Genes underlying Global Warming Adaptation Using Next-generation Sequencing: Application to Genetic Diversity Projection

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21996
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 22:Civil engineering and related fields
• Research Institution: Ehime University
• Principal Investigator: Watanabe Kozo 愛媛大学, 沿岸環境科学研究センター, 教授 (80634435)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: ゲノム / 適応遺伝子 / 次世代シークエンシング / 遺伝的多様性 / 河川

Outline of Final Research Achievements

In this study, we constructed a method to describe adaptive changes population genetic structure associated with changes in environmental gradients within a watershed due to climate change. We developed an adaptive evolution model for seven riverine aquatic insect species by searching the genome for environmentally selective loci that are affected by environmental factors related to global warming (e.g., water temperature and precipitation) and predicting their allele frequencies from environmental variables. Then, we predicted the spatial distribution of environmental variables at the basin scale under climate change scenarios, and predicted the spatial distribution of allele frequencies and genetic diversity by gapping with the above adaptive evolution model. The results showed that habitat reduction does not necessarily degrade genetic diversity when adaptive evolution is considered.

Free Research Field

応用生態工学

Academic Significance and Societal Importance of the Research Achievements

従来の気候変動下の遺伝的多様性の予測は，中立進化（環境選択を受けない）を前提としているが，現実には，例えば低水温に適応した遺伝子型は温暖化が起きれば，水温が低い高標高・高緯度地域に避難して存続できる可能性がある。しかし，従来法では中立遺伝子座が解析されてきたため，環境勾配に沿った遺伝子の「避難現象」を再現できず，遺伝的多様性の低下を過剰に予測する可能性が懸念される。本研究は、ゲノム上の環境選択性遺伝子に着目して，気候変動下における環境勾配に沿った遺伝子型の移動（避難）も考慮した上で，遺伝的多様性をより正確に予測するモデルを開発した点で高い学術的意義がある。