It was at the Drosophila meeting in San Diego 10-14th of April 2002. I had arrived with my uncle Einar Arnason and his late wife Betty, after driving down from Passadena. In the ginormous reception ball room we snacked and drank, until Einar was bundled by a springly fellow with wired hair and manners. Marty Kreitman had arrived at the scene.

Drosophila Research Conference (drosophila-conf.org)

I had greatly admired his population genetic work, though it was the work Marty did with Misha Ludwig that particularly impressed me. The first did population genetics on the best characterized regulatory element at the time, the stripe 2 enhancer of the eve (even-skipped) gene of D. melanogaster, and then moved to functional studies, comparing the element between species. See for instance a very impressive paper on chimeras of D. melanogaster and D. pseudoobscura s2e enhancers.

Evidence for stabilizing selection in a eukaryotic enhancer element.

To make a long story short, serendipity helped me make Marty´s acquaintance and a year later I started a postdoc with him and Misha at the University of Chicago. There we had three fun years doing population genetics on enhancers and analyzing gene expression in embryos.

Functional evolution of a cis-regulatory module. 2005. Ludwig MZ, Palsson A, Alekseeva E, Bergman CM, Nathan J, Kreitman M. PLoS Biology. 3(4):e93. (doi:10.1371/journal.pbio.0030093 PDF)

Canalization of segmentation and its evolution in Drosophila. 2007. Lott SE, Kreitman M, Palsson A, Alekseeva E, Ludwig MZ. Proc Natl Acad Sci U S A. 104(26):10926-31. (doi: 10.1073/pnas.0701359104 PDF)

Naturally Occurring Deletions of Hunchback Binding Sites in the Even-Skipped Stripe 3+7 Enhancer. 2014. Palsson A, Wesolowska N, Reynisdóttir S, Ludwig MZ, Kreitman M. PLoS ONE 9(5): e91924. doi:10.1371/journal.pone.0091924.

In the summer of 2022 former trainees and friends of Marty arranged a nice farewell symposium for him in Chicago. Thankfully I got to participate via zoom, and see some of the great people again.