Microsatellites indicate a high frequency of multiple paternity in Apodemus (Rodentia)

Area of Science:

• Ecology
• Genetics
• Mammalogy

Background:

• Understanding mating systems is crucial for population genetics.
• Multiple paternity, where a single litter is sired by more than one male, can influence population dynamics and genetic diversity.

Purpose of the Study:

• To estimate the frequency of multiple paternity in litters of two Apodemus mouse species.
• To analyze the genetic relatedness of offspring within litters using microsatellite markers.

Main Methods:

• Microsatellite genotyping was performed on DNA from pregnant female mice and their litters.
• Samples were collected from natural populations of striped field mice (Apodemus agrarius) and wood mice (Apodemus sylvaticus) in northern Ukraine.
• Analysis involved 11 microsatellite loci for A. agrarius and 9 for A. sylvaticus.

Main Results:

• Multiple paternity was detected in 80% of A. agrarius litters (8 out of 10) and 50% of A. sylvaticus litters (3 out of 6).
• Evidence of multiple sires was found across multiple microsatellite loci within individual litters.
• In two instances with A. agrarius, up to three different males were identified as fathers for a single litter.

Conclusions:

• Multiple paternity is a frequent occurrence in natural populations of Apodemus mice.
• These findings highlight the complex mating strategies and potential for high genetic variation within litters of these rodent species.