After learning that Ultrabithorax, a gene that specifies the development of wings, showed a localized pattern of expression similar to that of Antennapedia, they decided to revisit the classic papers of Ed Lewis. In 1978, Lewis had proposed that all these homeotic genes (the ones that tell animals where to put a wing and where to put a leg and so on) arose from a common ancestral gene. So McGinnis carved up the Antennapedia gene and, using those pieces as probes, the trio identified eight genes, which turned out to be the eight homeotic genes in flies. "That pissed off a lot of people," says Levine. "The homeotic genes were the trophies of the Drosophila genome. And we got 'em all. I mean, we got 'em all!" Far from being humble, Levine says, "We were like, 'We kicked your ass pretty good, didn't we, baby!' Those were the days."[3]
Levine briefly returned to UC Berkeley as a postdoctoral fellow[4] with Gerry Rubin.[8] He then joined the faculty of Columbia University, where he "led the discovery of the modular organization of the regulatory regions of developmental genes."[9] After isolating the even-skipped (eve) gene, Levine's team determined that each of the seven stripes was produced by separate enhancers.[3] With further study they discovered that both a set of activators and a set of repressors worked together to shape the expression of eve in the second stripe, and determined that the repressors shut down only their binding enhancers, leaving other enhancers free of repression.[3] Joseph Corbo said of the work,
"Before Levine's studies of even-skipped stripe 2, it wasn't clear how you generated spatially restricted patterns of gene expression from initially broad crude gradients of morphogens. I think that the even-skipped stripe 2 studies were the defining studies that showed how an organism can interpret those gradients and turn them into specific patterns of gene expression. To me that's Mike's crowning achievement."[3]
After earning tenure in only four years at Columbia,[3] Levine moved to UCSD in 1991,[4] where he added the sea squirt, Ciona intestinalis, to his repertoire. Although much of Levine's work, including his homeobox studies, has been done in Drosophila[6] Levine's team is also prominent in work with the sea squirt, Ciona intestinalis, an invertebrate that facilitates study of development.[3] For example, this work included insights into classical myodeterminants[10][11][12] and the composition of the notochord, the defining tissue of the chordate phylum.[13]
1996 - NAS Award in Molecular Biology - "For his insightful contributions to our understanding of gene regulation networks and molecular mechanisms governing the development of organisms with a segmented body plan."[16]
1998 - Elected to United States National Academy of Sciences in "Cellular and Developmental Biology" section: "Utilizing an elegant blend of in vitro and in vivo studies, Levine carried out insightful and complete analysis of regulatory events that govern segmentation and dorsal-ventral polarity in Drosophila. His work provided a dramatic example of combinatorial regulation at a complex enhancer and established new paradigms for transcriptional control."[17]
Levine cites as a significant influence his instructor Fred Wilt (taking his developmental biology class "was probably the single most galvanizing experience I had in terms of defining my future goals"),[8] and cites fellow scientists Eric Davidson, Peter Lawrence and Christiane Nusslein-Volhard as "mentors [and] friends ... over the years".[8]
On choosing to become a research biologist, he described some family pressure to become a doctor ("Coming from a modest background, particularly a Jewish family, the pressure to become a doctor was intense"),[3]
Han, Kyuhyung; Levine, Michael S.; Manley, James L. (1989). "Synergistic activation and repression of transcription by Drosophila homeobox proteins". Cell. 56 (4): 573–83. doi:10.1016/0092-8674(89)90580-1. PMID2563673. S2CID41210570.
^ abWilbur Cross Medal 2009 Winners Bios, Yale University (last visited 2012 July 29) ("The Wilbur Lucius Cross Medal is an honor presented each year by the Graduate School Alumni Association to a small number of outstanding alumni. The medal recognizes distinguished achievements in scholarship, teaching, academic administration, and public service–all areas in which the legendary Dean Cross excelled.")
^McGinnis, W.; Levine, M. S.; Hafen, E.; Kuroiwa, A.; Gehring, W. J. (1984). "A conserved DNA sequence in homoeotic genes of the Drosophila Antennapedia and bithorax complexes". Nature. 308 (5958): 428–33. Bibcode:1984Natur.308..428M. doi:10.1038/308428a0. PMID6323992. S2CID4235713.