Genetic Diversity Evaluation and Conservation of Topmouth Culter (Culter alburnus) Germplasm in Five River Basins in China

Abstract

To study the genetic diversity of Culter alburnus (C. alburnus) populations, we analyzed the genetic diversity of five C. alburnus populations from Songhua Lake (SH), Huaihe River (HH), Changjiang River (CJ), Taihu Lake (TH), and Gehu Lake (GH) based on mitochondrial COI gene sequences. The results showed that the average contents of bases T, C, A, and G in the 526 bp COI gene sequence were 25.3%, 18.1%, 28.1%, and 28.6%, respectively, which showed AT bias. A total of 115 polymorphic sites were detected in the five populations, and 11 haplotypes (Hap) were defined. The nucleotide diversity (Pi) of the five populations ranged from 0.00053 to 0.01834, and the haplotype diversity (Hd) ranged from 0.280 to 0.746, with the highest genetic diversity in the TH population, followed by the SH population, with lower genetic diversity in the HH, CJ and GH populations. The analysis of the fixation index (Fst) and the genetic distance between populations showed that there was significant genetic differentiation between the SH population and the other populations, and the genetic distances between all of them were far; the genetic diversity within populations was higher than that between populations. Neutral tests, mismatch distributions, and Bayesian skyline plot (BSP) analyses showed that the C. alburnus populations have not experienced population expansion and are relatively stable in historical dynamics.

Genetic structure and demographic history of Anguilla bicolor from Tanzania based on mitochondrial cytochrome oxidase I sequence: Implications for effective management and conservation strategies

“…The mutation rate was set at 1% per million years, based on the average mutation rate previously used in mtDNA COI region sequences in fish (He et al, 2022). The outputs and a summary of the posterior distribution of population size over time were visualized using Tracer v1.7 (Rambaut et al, 2018).…”

“…In this case, a standard Markov chain Monte Carlo (MCMC) analysis was run for 10 million generations, sampled every 1000 iterations under the general time reversible (GTR) evolutionary model. The mutation rate was set at 1% per million years, based on the average mutation rate previously used in mtDNA COI region sequences in fish (He et al, 2022). The outputs and a summary of the posterior distribution of population size over time were visualized using Tracer v1.7 (Rambaut et al, 2018).…”