Worm Breeder's Gazette 14(5): 70 (February 1, 1997)

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.

Cellular expression of the unc-116 gene encoding kinesin heavy chain.

M.Y. Ali, M.A. Shakir, Z.K. Siddiqui, M.L.A.Khan, S.S.Siddiqui

Laboratory of Molecular Biology, Toyohashi University of Technology, Tempaku-cho, Toyohashi-441, JAPAN

Previously in Caenorhabditis elegans, three kinesin genes osm-3 IV, aka
klp-2 (Shakir et al.,1993), unc-104 II, aka klp-1 (Otsuka et al., 1991),
and unc-116, aka khc (Patel et al.,1993) have been characterized. 
unc-116 encoded kinesin heavy chain contains the motor, stalk, and tail
domains (Patelet al.,1993). Mutants in unc-116 are defective in
locomotion, smaller in size and have no backward locomotion. The unc-116
encoded khc is required at two discrete timesin development : once
during very early embryogenesis,when it is supplied maternally, and the
other during larval development, when the khc is transcribed from the
zygotic genome ( David H.Hall, personal communication quoted by Patel 
et al., 1993).

To study the temporal and spatial expression of unc-116, a unc-116::lacZ
fusion gene was constructed. A  3.1 kb PstI-SalI fragment was obtained
from the cosmid R05D3, encoding the unc-116 gene. The fragment contains
1.3 kb of the promoter and 1.7 kb of the coding region. This fragment
was inserted in a lacZ expression vector pPD95.57, which included
nuclear localization signal (Fire et al.,1996). Two independent
transformed germ lines were obtained by microinjection, both of 
them showed an identical pattern of the lacZ staining. The staining of 
unc-116::lacZ reporter gene suggests that the unc-116 gene expresses
during all larval and adult stages of C. elegans.Staining is also
observed in the late embryos.  It is found that the unc-116 gene
expresses in a  subset of cells in the two pharyngeal bulbs and in the
tail. In L1 larva the staining is stronger in the posterior bulb than
the anterior bulb. But in the adult animals the staining in both the
anterior and posterior bulbs is stronger. Tentatively we have identified
the staining cells in the posterior bulb as RMG,  RIFL, RIS,ADA, 
ADE, AIM, AIY, AVA, AVB etc. and in the tail region PVT, PDB, PDA
located in the pre-anal ganglion. Further confirmation of cell
assignment is in progress using an unc-116::gfp construct.
Interestingly, we have not seen staining of any ventral cord motor
neurons, since the unc-116 mutants are defective in locomotion. This may
suggest that the gene may express in the set of interneurons located in
the head and tail, mediating locomotion. We are also examining the
unc-116::lacZ gene expression in various genetic backgrounds to 
see the regulation of unc-116 gene expression in different mutant

To observe the embryonic expression of the gene, we plan to use the in
situ hybridization approach using a unc-116 cDNA probe ( yk41e9), in the
wild type and mutant embryos.

We thank A. Coulson, Y.Kohara, A.Fire, D.Thiery-Mieg, and T.Stiernagle
for help in this project.