Abstract：Zebrafish Danio rerio embryos that 3 h post fertilization were incubated in a Petri dish and added 50 mL of 0 (clean water control), 2.2×108cfu/mL (high concentration), 1.1×108 cfu/mL (medium concentration), and 5.5×107 cfu/mL (low concentration) concentrations of Aeromonas veronii to soak the infection. The embryonic development was observed and taken photography under a bulk microscope at 6 h, 24 h, 32 h, 48 h, 56 h, 72 h and 80 h for calculation of embryonic death and hatchability, to research on the effects of A. vitilii infection on early embryonic development morphology. The total RNA of the embryos was extracted at 6 h and 24 h for transcriptome sequencing. It was found that significant increase in mortality and delayed development of viable embryos were observed in the zebrafish embryos exposed to A. veronii, with the longer delaying in embryo development at higher concentration of A. veronii. Under the infection at a concentration of 2.2×108 cfu/mL , the developmental period stagnated at 8—14 hours post fertilization (hpf). However, the embryos infected by A. veronii at 2.2×108cfu/mL were put back into clean water and continued to develop forward again. The transcriptome results of the changes in gene expressions related to the developmental process of the embryos exposed to A. veronii revealed that the 22 differentially expressed genes related to the developmental process were screened, most of whose functions were involved in the development of the mesoderm, especially in the embryonic dorsolization. So, we speculated that A. veronii changed the expression of genes related to the dorsolization of mesoderm development or the activity of upstream regulatory factors, resulting in the delayed development of zebrafish embryos.
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2024, Vol. 43 
