miR-29a Is Downregulated in Progenies Derived from Chronically Stressed Males

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Paternal stress exposure is increasingly recognized for its potential to influence offspring phenotypes.
• The mechanisms by which paternal stress impacts progeny development, particularly at the molecular level, require further elucidation.

Purpose of the Study:

• To investigate the hypothesis that paternal chronic stress negatively impacts zebrafish progeny.
• To identify molecular alterations, specifically microRNAs (miRNAs), and physiological changes in offspring resulting from paternal stress.

Main Methods:

• Zebrafish males were subjected to a 21-day chronic stress protocol.
• RNA sequencing (RNA-seq) was employed to identify differentially expressed small noncoding RNAs in larvae from stressed sires.
• Validation of differentially expressed miRNAs was performed in larvae, sperm, testicles, and brain tissue.

Main Results:

• A single microRNA, miR-29a, was found to be significantly downregulated in larvae from paternally stressed males.
• This downregulation of miR-29a was observed vertically, indicating transmission of stress effects to unexposed offspring.
• Affected offspring exhibited reduced survival and hatching rates, alongside potential impacts on development, morphogenesis, and neurogenesis.

Conclusions:

• Paternal chronic stress can be vertically transmitted to offspring, inducing molecular changes like miR-29a deregulation.
• The observed molecular alterations in offspring are associated with compromised development and reduced viability.
• These findings highlight novel molecular consequences of paternally inherited chronic stress, impacting offspring health and development.