Neurodevelopment vs. the immune system: Complementary contributions of maternally-inherited gene transcripts and proteins to successful embryonic development in fish

The aim of this study was to investigate the respective contribution of maternally-inherited mRNAs and proteins to egg molecular cargo and to its developmental competence in fish using pikeperch as a model. Our study provides novel insights into the understanding of type-specific roles of maternally-inherited molecules in fish. Here we show, for the first time, that transcripts and proteins have distinct, yet complementary, functions in the egg of teleost fish. Maternally-inherited mRNAs would shape embryo neurodevelopment, while maternallyinherited proteins would rather be responsible for protecting the embryo against pathogens. Additionally, we observed that processes directly preceding ovulation may considerably affect the reproductive success by modifying expression level of genes crucial for proper embryonic development, being novel fish egg quality markers (e.g., smarca4 or h3f3a). These results are of major importance for understanding the influence of external factors on reproductive fitness in both captive and wild-type fish species.

Automated summary

This study investigates the contribution of maternally-inherited mRNA and proteins to fish egg molecular cargo and developmental competence using pikeperch as a model. The findings reveal distinct functions of transcripts and proteins in fish eggs, with mRNA shaping embryo neurodevelopment and proteins protecting against pathogens. Pre-ovulation processes can significantly impact reproductive success by modifying gene expression crucial for embryonic development, serving as novel markers for fish egg quality. These results are crucial for understanding the impact of external factors on reproductive fitness in fish species.