Solenopsis invicta Gp-9 RAD analysis

In the fire ant Solenopsis invicta, the existence of two divergent forms of social organisation is under the control of a single Mendelian genomic element marked by the gene Gp-9. Here we characterize the genomic region responsible for this important social polymorphism and show that it is part of a pair of heteromorphic chromosomes having many of the key properties of sex chromosomes.