Efficiently whole-genomic mutagenesis approach by ARTP in blunt snout bream (Megalobrama amblycephala)

The atmospheric and room temperature plasma (ARTP) mutagenesis technique was first used in the present study to produce whole-genomic mutants in blunt snout bream ( Megalobrama amblycephala ). The optimal ARTP mutation parameters for semen were established according to sperm motility and abnormal embryonic rate. A total of 2026 mutated offsprings were produced with normal and abnormal individuals with a ratio of approximately 1:1. Among them, 384 normal mutant fish (~20%), after three months of cultivation, demonstrated improved performance with either fast growth or hypoxia tolerance, and 89 mutant individuals with both hypoxia tolerance and fast growth (H&F). The average bodyweight of the H&F fish increased by 26.48% compared with the control group. The average oxygen tension threshold for loss of equilibrium (LOE crit ) of the H&F fish was 0.45 mg/L, significantly ( p < 0.05) lower than 0.86 mg/L in the control group. Meanwhile, the red blood cell count, hemoglobin concentration, and Na + /K + -ATPase enzyme activity of the H&F group increased significantly ( p < 0.05), whereas, the gill tissue cell apoptosis rate decreased considerably ( p < 0.05), suggesting that they are hypoxia tolerant. According to the genome resequencing analysis, 3,195,434 SNPs and 927,930 InDels were found in the H&F group, which were significantly higher than the 9127 SNPs and 2908 InDels in the control group. The average mutation rate in the H&F fishes reached 2.98 × 10 −3 at the genome level, approximately 350 times that of the control group. Importantly, 3651 special non-synonymous SNP mutations were found in the H&F fish, which are located in 1223 genes. Among them, eight hypoxia- and growth-related genes with non-synonymous mutations at one or more sites were differentially expressed (DE) in H&F fish. Taken together, our results establish a novel whole-genomic mutagenesis approach using ARTP in blunt snout bream, which should be useful for future genetic breeding. • Total 2026 ARTP-mutated offsprings were produced with the optimal ARTP mutation technique. • 4% ARTP-mutant individuals (89 fish) with both hypoxia tolerance and fast growth. • The average mutation rate reached 2.98 × 10 −3 at the genome level, about 350 times than that of the control group. • 3,195,434 SNPs and 927,930 InDels were found in the ARTP-mutated group, which were 350 and 320 times higher than those in control group.