Sperm pre-fertilization thermal environment shapes offspring phenotype and performance

Area of Science:

• Reproductive Biology
• Environmental Physiology
• Evolutionary Biology

Background:

• Sperm's pre-fertilization environment may influence offspring traits (transgenerational plasticity).
• The adaptive significance of this sperm-mediated transgenerational plasticity remains largely unknown.
• Understanding these effects is crucial for predicting species' responses to environmental change.

Purpose of the Study:

• Investigate transgenerational effects of sperm pre-fertilization thermal environment.
• Assess the impact on offspring phenotype and performance in European whitefish.
• Clarify the adaptive significance of sperm's thermal history.

Main Methods:

• Full-factorial breeding design with European whitefish (Coregonus lavaretus).
• Sperm pre-incubation at 3.5°C vs. 6.5°C for 15 hours prior to fertilization.
• Evaluated sperm traits, fertilization success, embryo mortality, offspring size, and swimming performance.

Main Results:

• Sperm thermal pre-treatment did not affect sperm motility, size, or fertilization success.
• Offspring fertilized with sperm exposed to 6.5°C were smaller and had poorer swimming performance.
• Interactions between thermal treatment, female, and male affected embryo mortality.

Conclusions:

• Sperm's pre-fertilization thermal environment significantly shapes offspring phenotype and post-hatching performance.
• Short-term thermal changes in sperm can negatively impact offspring fitness.
• Sperm thermal environment is a key factor in organismal adaptation potential to climate change.