M(6)A transcriptome-wide map of circRNAs identified in the testis of normal and AZ-treated Xenopus laevis

BACKGROUND: Evidence showed that N(6)-methyladenosine (m(6)A) is strongly associated with male germline development. However, the role of m(6)A methylation on circRNAs in amphibians remains unknown. In this study, we conducted m(6)A sequencing analysis to explore the m(6)A transcriptome-wide profile of circRNAs in testis tissues of Xenopus laevis (X. laevis) with and without treatment with 100 µg/L atrazine (AZ). RESULTS: The analysis showed that m(6)A modification of circRNAs enriched in sense overlapping in testes of X. laevis. We identified the differential m(6)A modification sites within circRNAs in testes of AZ-exposed X. laevis and compared that with animals from control group. The results showed that a total of 1507 methylated m(6)A sites was induced by AZ (760 up-methylated and 747 down-methylated). The cross-analysis exhibited a negative correlation of differentially methylated m(6)A peaks and circRNAs expression level. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that 20 key pathways may be involved in the mechanism of testis damage of AZ-exposed X. laevis. CONCLUSIONS: These findings indicated that differentially m(6)A-methylated circRNAs may play important roles in abnormal testis development of AZ-exposed X. laevis. This study is the first report about a map of m(6)A modification of circRNAs in male X. laevis and provides a basis for further studying on the function and mechanism of m(6)A methylation of circRNAs in the testis development of amphibian. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s41021-023-00279-0.