MULTIPLE PATERNITY IN THE LEAFCUTTER ANT ATTA-COLOMBICA - A MICROSATELLITE DNA STUDY

An evolutionary understanding of the causes, correlates and consequenc es of multiple paternity in eusocial Hymenoptera (all ants, some bees and some wasps) relies on accurate estimation of this parameter at the species, population and colony level. We developed dinucleotide micro satellite DNA markers in order to study in detail the degree of multip le paternity in a population of tile monogynous Panamanian leafcutter ant Atra colombica. These microsatellite markers were highly polymorph ic such that nondetection caused by finite allelic diversity was very low (0.016). Hence, accurate information on the patterns of multiple p aternity could be obtained. Genetic analysis revealed that in 33 out o f 36 colonies two or more males had contributed genetically to the off spring. The mean number of fathers per colony was 2.6 and the mean eff ective paternity was 2.31. These are the highest values of effective p aternity yet reported fur any ant species, We examined the patterns of paternity frequency in young and old colonies to test if within-colon y genetic diversity is related to colony survival, but found no suppor t for any relationship. Our results confirm previous nongenetic studie s showing high levels of multiple mating by queens of higher leafcutte r ants. We discuss our findings in relation to known patterns of polya ndry and paternity in other eusocial Hymenoptera.