Publications by authors named "Xiao-Xu Pang"
Article Synopsis
- Ghost introgression involves the transfer of genetic material from extinct lineages into currently existing species, with limited evidence found in plants, particularly for Carya sinensis and Carya cathayensis.
- Researchers assembled chromosome-level genomes for these species and re-sequenced 43 C. sinensis individuals and 11 diploid hickory species to explore genetic patterns and confirm ghost introgression.
- Their analysis, employing methods like D-statistic and BPP alongside phylogenetic network analysis, provided strong evidence of ghost introgression in C. sinensis from an extinct lineage, enhancing the understanding of Carya's evolutionary history and biogeography.
Article Synopsis
- Recent research on hybridization highlights the concept of ghost introgression, where genetic material is transferred from extinct or unsampled species to living ones.
- The study assesses various phylogenetic methods, particularly comparing heuristic approaches and the full-likelihood method BPP, in detecting ghost introgression in a controlled scenario with known species relationships.
- Results indicate that while common methods struggle to accurately identify ghost introgression, the full-likelihood BPP method effectively analyzes complex datasets, as demonstrated by its application to a dataset of Jaltomata species.
Article Synopsis
- Autopolyploidy serves as an effective model for studying how whole-genome duplication affects genomic changes; this research focuses on Cyclocarya paliurus, a species with both diploid and autotetraploid forms.
- The study revealed that the autotetraploid genome has 64 chromosomes with clusters showing similarity in length and gene expression, alongside significant genetic structural variations.
- It was found that many genes displayed allelic loss, particularly near structural variations and transposable elements, though genes with multiple copies had higher expression linked to stress response, indicating evolutionary advantages for autotetraploids.
Article Synopsis
- The study investigates the genetic relationships within the walnut family (Juglandaceae) using data from seven chromosome-level genomes, including two newly assembled genomes.
- Through analyses of microsynteny and gene content, the research confirms previous findings that associate Platycarya with Engelhardia, contrasting with DNA alignment methods that link Platycarya to Carya and Juglans due to past hybridization.
- The research also suggests that Juglandaceae likely originated from hybridization events involving now-extinct or unsampled progenitors closely related to Myricaceae, with Rhoiptelea chiliantha exhibiting a unique slower evolutionary rate and a higher proportion of DNA repair genes compared to other species in the family.
The species studied in any evolutionary investigation generally constitute a small proportion of all the species currently existing or that have gone extinct. It is therefore likely that introgression, which is widespread across the tree of life, involves "ghosts," that is, unsampled, unknown, or extinct lineages. However, the impact of ghost introgression on estimations of species trees has rarely been studied and is poorly understood.
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