Maternal effects regulate population genetic structure by altering intraspecific competitive relationships

Summary 1. The transgenerational plasticity of maternal effects on offspring phenotypes has been well recognized, however, weather maternal effect can drive dynamic changes in population genetic structure by modifying the competitive dynamics among offspring is still unclear. 2. After evaluation of the reliability of COI metabarcoding for intraspecific clone quantification using a monogonont rotifer Brachionus calyciflorus as the model animal, a high-frequency dynamic monitoring experimental system was set to measure maternal effect on temporal dynamics in gene frequencies within mixed populations containing morphologically identical clones. 3. Results showed that maternal effects significantly enhanced the competitive fitness of the target offspring clone, leading to a rapid increase in its frequency inside the population. However, this advantage last for a few generations, and gradually diminished or even reversed as the maternal effects attenuated across generations. 4. Temperature dynamically affected the duration of maternal effect: higher temperature shortened the duration of maternal effects on population genetic dynamics, while lower temperature prolonged it. 5. By population dynamic monitoring, this study revealed the transient nature of maternal effect as a non-genetic buffering mechanism, providing an integrative theoretical framework for understanding the dynamic integration of short-term plasticity and long-term selection pressure in adaptive evolution of intraspecific clones.