Genetic Diversity and Phylogenetic Relationships of Castor Fiber Birulai in Xinjiang, China

Recent research by a team of scientists from Xinjiang University has shed new light on the genetic diversity and phylogenetic relationships of Castor fiber birulai, a subspecies of the Eurasian beaver. The study, published in the journal Animals, analyzed mitochondrial cytochrome b and D-loop sequences from 19 individuals residing in the Buergen River Basin, Xinjiang, China. The findings suggest that Castor fiber birulai has a relatively small population size compared to other Castor subspecies and has undergone significant genetic differentiation from other Eurasian lineages.

Key Takeaways:

• The research analyzed mitochondrial cytochrome b and D-loop sequences from 19 individuals of Castor fiber birulai in the Buergen River Basin, Xinjiang, China.
• The study found that the genetic diversity within the Chinese population of Castor fiber birulai was low, with a haplotype diversity (Hd) of 0.444 and a nucleotide diversity (Pi) of 0.0043.
• Phylogenetic reconstructions and haplotype network analyses revealed significant genetic differentiation between Castor fiber birulai and other Eurasian lineages (Fst = 0.95), supporting the status of Castor fiber birulai as a distinct evolutionary lineage.
• Demographic analyses provided no evidence of recent population expansion, suggesting a demographically stable population.
• The study recommends increasing nuclear gene data to verify whether the Castor fiber birulai population meets the criteria for Evolutionarily Significant Unit classification.
• Strengthening cross-border protection and cooperation between China and Mongolia is also recommended to prevent anthropogenic disturbances, such as hydraulic infrastructure and fencing, from impeding gene flow and dispersal.

Statistics:

• 19 individuals of Castor fiber birulai were analyzed in the study.
• The genetic diversity within the Chinese population was low, with a haplotype diversity (Hd) of 0.444 and a nucleotide diversity (Pi) of 0.0043.
• The genetic distance between the Chinese and Mongolian populations was relatively small, with a distance of 0.00269.
• Significant genetic differentiation was detected between the Chinese and Mongolian populations, with a Fst value of 0.67055.

Sources:

• Genetic Diversity and Phylogenetic Relationships of Castor fiber birulai in Xinjiang, China, Revealed by Mitochondrial Cytb and D-loop Sequence Analyses. Animals, 2025,15(14):2096.
• Zhu, L., et al. (2025). Genetic Diversity and Phylogenetic Relationships of Castor fiber birulai in Xinjiang, China, Revealed by Mitochondrial Cytb and D-loop Sequence Analyses. Animals, 15(14), 2096.
• MDPI AG. (2025). Animals. doi: 10.3390/ani15142096.