人工繁育环境中长江鲟繁殖活动的环境DNA动态研究OA

We applied digital PCR targeting mitochondrial DNA(mtDNA)and nuclear DNA(nuDNA)markers to investigate environmental DNA(eDNA)dynamics during artificial propagation of the critically endangered Yangtze sturgeon(Acipenser dabryanus).Species-specific primers and TaqMan probes were designed to quantify mtDNA and nuDNA concentrations and their ratio(nuDNA/mtDNA)across different reproductive stages.Both mtDNA and nuDNA levels increased rapidly and reached their peaks after spawning.In the male pond,concentrations rose to 27-fold(mtDNA)and 130-fold(nuDNA)of pre-spawning levels following sperm release;in the female pond,concentra-tions increased to 8-fold(mtDNA)and 13-fold(nuDNA)after ovulation.The nuDNA/mtDNA ratio peaked at 0.14 and 0.09 in the male and female ponds,respectively.Overall,peak mtDNA concentrations were approximately 11-12 times higher than those of nuDNA and remained detectable for 24-36h,indicating greater persistence.In contrast,nuDNA concentrations declined sharply within 12h post-spawning,demonstrating high temporal sensitivity to spawning events.Our findings demonstrate that eDNA monitoring effectively captures molecular signatures and temporal patterns of A.dabryanus reproductive activity,offering a robust,non-invasive tool for studying the reproductive ecology and inform-ing conservation strategies for endangered fish species.