Genomic Insights Into Introgression Between Quercus aquifolioides and Its Sympatric Relatives Across Elevational...

Area of Science:

• Evolutionary Biology
• Genomics
• Plant Science

Background:

• Widespread species often hybridize, but evolutionary outcomes of multi-species hybridization remain unclear.
• Oaks in China's Hengduan Mountains exhibit complex hybridization patterns involving Quercus aquifolioides and related species.

Purpose of the Study:

• Investigate genome-wide introgression patterns in Quercus aquifolioides.
• Assess the evolutionary consequences of multi-species hybridization in this oak complex.
• Understand the role of introgression in intraspecific divergence and adaptation.

Main Methods:

• Utilized a newly assembled genome of Quercus longispica as a reference.
• Performed whole-genome resequencing of focal oak species.
• Analyzed genome-wide introgression patterns and signatures of selection.

Main Results:

• Confirmed bidirectional gene flow between Quercus aquifolioides and its sympatric relatives.
• Identified widespread introgression across the oak genome, driving regional divergence.
• Detected positive selection in introgressed regions, indicating adaptation in genes related to stress response and development.

Conclusions:

• Local introgression is a significant factor in intraspecific divergence of Quercus aquifolioides.
• Evidence suggests adaptive introgression between Quercus aquifolioides and its relatives.
• Hybridization facilitates adaptation to local environments through gene flow.