Maternal age generates phenotypic variation in Caenorhabditis elegans

Area of Science:

• Developmental Biology
• Genetics
• Animal Behavior

Background:

• Phenotypic variation exists even in genetically identical organisms within the same environment.
• The underlying causes of this variation are often not well understood.
• This phenomenon is observed across diverse species, including humans and model organisms like *C. elegans*.

Purpose of the Study:

• To investigate the causes of phenotypic variation in isogenic *Caenorhabditis elegans*.
• To identify the molecular mechanisms responsible for observed differences in offspring.
• To explore potential fitness trade-offs related to maternal age.

Main Methods:

• Utilized isogenic *Caenorhabditis elegans* populations.
• Assessed multiple phenotypic traits including size, development speed, growth rate, starvation resistance, and fecundity.
• Analyzed maternal provisioning of vitellogenin to embryos across different maternal ages.

Main Results:

• Significant phenotypic variation was observed in size, development, growth, starvation resistance, and fecundity among isogenic nematodes.
• Maternal age was identified as the primary driver of this variation, with progeny of younger mothers showing impairments.
• Age-dependent changes in maternal vitellogenin provisioning to embryos were identified as the molecular mechanism.

Conclusions:

• Maternal age is a critical factor influencing offspring phenotype in *C. elegans*.
• Vitellogenin provisioning is a key molecular mechanism mediating the effects of maternal age on offspring traits.
• The findings suggest a trade-off between maternal fitness strategies, balancing generation time with offspring quality.