New insights into transcriptional and metabolic differences between pregnant males and embryos in seahorses

Abstract

Seahorses exhibit a unique reproduction mode of male pregnancy. Successful gestation plays a crucial role in the seahorse reproduction process and the aquaculture industry. However, the substantial paternal-embryo differences in seahorses remain largely unexplored. In the present study, transcriptomic and metabolic differences between pregnant males and embryos during gestation were explored to investigate the roles of key genes and metabolites in pregnant males and embryos in seahorses. Higher levels of essential amino acids and polyunsaturated fatty acids in embryos compared to fathers may indicate their vital role in embryonic development. The high expression of immune-related genes (CCLs and CCRs) and downregulation of antioxidants in fathers may provide immune protection and reduce the immunological rejection of embryos during gestation. The transcript-metabolite correlation network during pregnancy further indicated the role of key genes and metabolites during embryonic eye (N-acetyl-L-histidine, PAX6, and FZT4) and tail (WNT5 and WNT8) development. The findings of the present study not only provide valuable data on differences between pregnant males and embryos in seahorse, but also lay foundation for future research on seahorse aquaculture.