1. MaineHealth Institute for Research, MaineHealth, Scarborough, ME (A.S., C.P., A.K., A.H., M.M., B.T., J.S., I.P., C.V., L.R., L.L.).
2. Graduate School of Biomedical Science and Engineering, University of Maine, Orono (A.S., M.M., R.K., I.P., C.V., L.L.).
3. The Jackson Laboratory, Bar Harbor, ME (G.L.S., R.K.).
4. Now with Department of Molecular and Cellular Biology, University of Arizona, Tucson (G.L.S.).