缺失ca12基因显著提高草鱼耐碳酸盐碱度胁迫能力OA

To explore the function of carbonic anhydrase 12(ca12)in grass carp(Ctenopharyngodon idella)response to carbonate alkalinity stress,we subjected grass carp to alkalinity stress at different NaHCO3 concentration gradients(0,20,40,60,80,100,150 mmol/L),and systematically analyzed the expression level of ca12 in various tissues(brain,heart,kidney,and gill)as well as the histopathological changes in gill and intestinal tissues.Compared with wild-type grass carp,chimeric grass carp edited by CRISPR/Cas9 technology had higher survival rate at different alkalinity levels and time points.Moreover,the expression levels of ca12 in the kidney and gill tissues were significantly downregu-lated with increasing alkalinity.Under stimulation with 60 mM/L NaHCO3,gill and intestinal tissues of chimeric grass carp showed adaptive morphology changes,with a significantly lower apoptosis rate than that of wild-type grass carp,and the survival rate of chimeric grass carp was also higher under this condition.The study indicates that high alkali-nity stress exerts adverse effects on grass carp,and the chimeric grass carp edited by CRISPR/Cas9 technology display significantly higher survival rates in high-alkalinity water than wild-type grass carp.This suggests that the ca12 plays an important regulatory role in grass carp under high-alkaline conditions,making it a critical target for grass carp adap-tion to high-alkaline environments.Loss of ca12 function significantly enhances the alkalinity tolerance of grass carp,providing a new strategy to improve the aquaculture rate in saline-alkali areas and expand the development space of the fishery industry.