Worm Breeder's Gazette 12(5): 72 (February 1, 1993)

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.

Novel Conserved Functions of Neurons

Tom Barnes, Gary Ruvkun

Department of Molecular Biology, Wellman 8, MGH, Boston, MA 02114 USA

Although many fundamental processes occurring in the nervous system are well characterized, many others remain poorly characterized or even unknown. It has been shown that up to 50% of the single-copy sequences of the vertebrate genome are neurally expressed, and about one half of these appear to be unique to the brain. Recent surveys of gene sequences expressed in Homo sapiens (2,3) and Caenorhabditis elegans (4,5) have shown that the majority appear to encode unfamiliar proteins. Thus for C. elegans, where a large number of genes required for normal nervous system development or function has been defined by mutation, many such genes will probably encode unfamiliar proteins and be required thus for incompletely characterized processes. We are specifically interested in such nervous-system genes (defined as encoding unfamiliar proteins) and in characterizing these processes further, as long as these genes are evolutionary conserved (defined as having identifiable vertebrate homologs) . The advantage of using a set of mutationally-defined, rather than randomly cloned, genes as the source material is that we will be able to use genetic tools to help elucidate functions.

The advanced state of physical map of the genome makes a systematic analysis of a reasonable number of genes possible. We started with those genes whose cloning, using the physical map of the genome, should be most straightforward. After critically examining the genetic and physical genome maps, we chose a set of 10 genes: unc-10 , unc-11 , unc-14 , unc-24 , unc-26 , unc-37 , unc-63 , unc-67 , unc-74 and daf-14 .The DNA from the regions to which these genes have been delimited was prepared (111 cosmids). Two of the genes ( unc-63 and unc-74 )are being located by looking for rearrangements in Southerns, from a set of alleles provided by Jim Lewis in collaboration. Cosmid miniprep DNAs were pooled for the remaining 8 genes (1 to 22 cosmids per pool; typically 12-15) at a concentration of 0.5 ~ g/ml for each cosmid. All except unc-26 were rescued. The seven successfully rescued genes will now be further localized by splitting the pools. It is remarkable that a pool of 22 cosmids, having a complexity of 0.5 Mb, was able to rescue.

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