[
Worm Breeder's Gazette,
2002]
We describe the molecular characterization of laboratory strains of the nematode genus Pristionchus , which lays a foundation for microevolutionary analyses of vulva development. We isolated 13 laboratory strains of the Pristionchus genus that are derived from natural isolates from around the world. Mating experiments and ITS sequence analysis indicated that these 13 strains represent four different species; the gonochoristic species P. lheritieri and three hermaphroditic species, P. pacificus , P. maupasi and an as yet undescribed species Pristionchus sp., respectively. P. pacificus is represented by five different strains isolated from California, Washington, Hawaii, Ontario and Poland. Our working 'wild type' strain is the California strain. Since polymorphisms are becoming an important tool in modern day genomic analysis, which facilitate cloning of mutations, we decided to search for polymorphisms in the various Pristionchus pacificus strains. We performed amplified restriction fragment length polymorphism (AFLP) analyses of the different P. pacificus strains and found that the American strains are highly polymorphic (Srinivasan et al., 2001). We observed the largest genetic variation between the strain from California on the one hand and Washington and Hawaii on the other hand. In contrast, the developmentally distinct strain from Poland is identical to the Californian strain. Hence, we chose the Washington strain as our polymorphic strain for future experiments. These results provide us a framework for further studies on microevolution in developmental processes. Reference: Srinivasan, J., Pires-daSilva, A.; Gutierrez, A.; Jungblut, B.; Zheng, M.; Witte, H.; Schlak., I. & Ralf J. Sommer, Evolution & Development (2001) 3 : 229-240.