Worm Breeder's Gazette 15(3): 32 (June 1, 1998)

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.

Expression of the unc-116 encoded kinesin heavy chain in the, muscle, nervous system, and germ line of C. elegans

M.Yusuf Ali1, Zeba K.Siddiqui1, M.Liakot Ali Khan1, Takashi Matsuo1, Fumio Hori1, K., Nishikawa2, Tomoko Motohashi2, Yuji Kohara2, Shahid S. Siddiqui1

1 Laboratory of Molecular Biology, Dept of Ecological, Engineering, Toyohashi, University of Technology, Toyohashi 441, Japan
2 DNA Library Lab, National Institute of Genetics, Mishima, 411, Japan

Kinesin is the founding member of a superfamily of ATPases that
transportcellular cargo on microtubule tracks. In C. elegans unc-116
gene encodes the kinesin heavy chain (Patel et al., 1993). We plan to
characterize all members of the kinesin superfamily, and have recently
described idenitification of klp-1 -  klp-14  genes encoding different
kinesin like proteins in C.elegans (Khan et al., 1997). These include
five previously identfied genetic loci, osm-3, unc-104, unc-116, vab-8
and zen-4. Here we report temporal and spatial expression of the UNC-116
kinesin heavy chain (KHC),  using RNA insitu hybridization  and a newly
constructed  unc-116::lacZ reporter gene during embryonic and
post-embryonic development. 

Previously we have reported expression of the unc-116::lacZ reporter
gene in the set of interneurons tentatively identified as RMG, RIFL,
RIS, ADA,ADE,AIM, AIY, AVA, AVB, etc. in the anterior ganglia located in
the head, and PVT,PDA, PDB, located in the pre-anal ganglion.(WBG 14,
#5, p70, 1997, and The 1997 C. elegans meeting abstracts p682).However
this pattern was a bit unusual since the unc-116 mutants are defective
in locomotion, coil as young larvae, and display abnormal backward
movement during late larval and adult life, thus we expected unc-116
expression in the ventral cord motor neurons.  We therefore constructed
a larger unc-116 promoter that added about 0.4 kb upstream sequence in
the promoter region, and fused it with the pPD95.57 (A. Fire) lacZ
expresion vector. Germline  transgenics were obtained by injecting this
large promoter construct and  stained for the lacZ activity. Intense
staining was observed in late embryos, all larval stages and in adults
of both sexes. In particular the body wall and pharyngeal muscles,
stained weakly in young larvae, but staining increases gradually,
reaching a maximum in L3-L4 stage and stays  that way during adult
stage. Staining of the nervous system is strong, and include the set of
motor neurons along the ventral nerve cord,nerve ring in the head,
neurons in the anterior and posterior ganglia. In the pharynx, cells in
the anterior and terminal bulb are strongly stained.Staining of sensory
neurons in the head (amphid and labial) and in the tail (phasmid) is
weak but noticeable. The ventral and dorsal nerve cords and some lateral
processes are also stained. We have also perofrmed in situ RNA
hybridizations using a unc-116 cDNA clone, during embryonic (Tabara et
al., 1996), and post-embryonic development (Y. Kohara, unpublished), and
found that the large promoter expression is consistent with the in situ
hybridization patten observed in the larval and adult stages.  During
early embryonic cleavages, heavy expression of the unc-116 gene is
observed, that is somewhat reduced in later stages, but continues during
most of the embryonic development. Dissected gonads show strong
hybridization signal in developeing oocytes, but meiotic cells in the
gonad apparently do not express the signal. We have begun analysis of
unc-116::lacZ reporter gene expression in different mutant backgrounds,
and find that expression in the muscle and motor neurons is
significantly reduced in the unc-104(rh 1016) mutant background,
especially during the larval stages. Similarly expression of the
reporter gene is eliminated or extremely reduced in the nerve ring and
some muscle cells in the vab-8(e1017) mutant background. Since UNC-104
and VAB-8 are kinesin like proteins, these observations suggest
interaction of multiple kinesins in muscle and neural development of C.
elegans. Experiments are in progress using various mutant backgrounds to
test the embryonic and postembryonic interaction of UNC-116 KHC with
other kinesin and non-kinesin proteins.

We thank D. Thierry-Mieg, E. Hedgecock, A. Otsuka,, D.  Hall, R.
Holmgren, J. Miwa, H. Tabara and J. white for encouragement; Theresa
Stierngale and A. Fire for strains and vectors, and Sanger Centre for
genomic sequence information.