Induction of haploid zebrafish and analysis of resultant developmental defects and aberrant gene expression

Haploid syndrome represents a fatal phenotypic condition that manifests during the embryonic stages of teleost fish, posing challenges for genetic screening and aquaculture breeding. This research employs zebrafish as a model to pinpoint the critical spectrum of developmental abnormalities that arise post-haploid induction and to uncover the primary transcriptomic dysregulation network along with potential functional genes. Haploid zebrafish embryos were produced using gynogenesis facilitated by sperm that had been exposed to ultraviolet radiation. The haploid condition was verified through flow cytometry and chromosome karyotype assessments. Whole-transcriptome sequencing was conducted via RNA sequencing (RNA-seq) across various phenotypic categories to pinpoint differentially expressed genes. Enrichment analysis, co-expression network construction, and quantitative reverse transcription PCR (qRT-PCR) were utilized to identify relevant functional modules and key regulatory genes. The haploid embryos displayed characteristic phenotypes such as body axis curvature, pericardial edema, and early mortality, with a hatching rate significantly lower than that of the diploid control group. Transcriptomic analysis identified 2247 differentially expressed genes, with 13 genes consistently recognized across several group comparisons. Their functional enrichment was notably focused on the FGF/Wnt signaling pathway, mitochondrial translation, ion transport, cell cycle regulation, and other essential hub genes linked to developmental anomalies. Additionally, their expression levels showed a significant dose-dependent correlation with the extent of malformations. The results of this study suggest that the lethal developmental issues associated with haploid syndrome stem from the combined dysregulation of multiple pathways, establishing a set of key target genes for potential intervention. This research lays a theoretical groundwork and offers practical strategies for improving haploid survival rates, holding considerable promise for advancements in fish haploid breeding technology. • The key developmental abnormal phenotype spectrum after haploid induction have been characterized. • Functional enrichment analysis of haploid-specific DEGs was carried out. • Thirteen candidate functional genes associated with haploid developmental abnormalities were identified.