Population genetic structure of blacks rats in an urban environment: a case study in Cotonou, Benin

The cosmopolitan black rat, Rattus rattus , has invaded many cities throughout the world. Although the species is responsible for major damages to food stocks and crops and is involved in the main-tenance, circulation and transmission of many zoonotic pathogens to humans and animals, a lot remains to be known about its eco-evolutionary characteristics, especially in highly modified en-vironments like the urban habitat. In particular, very few studies were conducted on the genetic structure of urban black rat populations, which is yet a prerequisite for defining effective management units. Here, we focus on the population genetics of Rattus rattus in Cotonou, Benin. Forty different localities were sampled throughout the city and 457 individuals were genotyped using 18 microsatellitemarkers. Ourresultsrevealtwopoorlydistinguishablebutsignificantgeneticclusters, one of each side of Cotonou channel, that tend to homogenize into a single group due to probable gene flow between the two shores. Implications in terms of management units and rodent control are discussed.