Worm Breeder's Gazette 14(2): 81 (February 1, 1996)
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
1 | Department of Biology, Boston University, Boston, MA |
2 | Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO |
3 | Department of Cell Biology, Vanderbilt University Medical Center, Nashville, TN |
unc-4 encodes a homeodomain protein [1] that determines the pattern of synaptic input to VA motor neurons in the ventral cord [2]. unc-4 mutations lead to an uncoordinated phenotype whereby animals can crawl forward but not backward. Electron microscopic examination of unc-4(e120) revealed that VA motor neurons, which are necessary for backward movement, receive synaptic input normally reserved for their sister cells, the VB motor neurons [2]. Experiments with unc-4-lacZ reporter genes detected expression in all A-type motor neurons (SAB, DA, VA) and demonstrated that unc-4 activity in the VAs in L1/L2 larvae is sufficient to establish connections with the appropriate interneurons [3]. Thus, one unc-4 function is to distinguish the fates of VA and VB sisters cells with respect to presynaptic input.