Worm Breeder's Gazette 8(1): 39

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.

Further Analysis of Collagen Genes in C. elegans

J. Kramer, J. Cox, D. Hirsh

We have been studying the collagen gene family of C.  elegans for 
insights into the regulatory and assembly processes that create the 
distinct cuticles formed at the molts.  We have found that the 
collagen gene family contains 50-150 members, the majority of which, 
we believe, encode cuticle collagens.  Genetic mapping using 
Bristol/Bergerac polymorphisms has shown that members of the gene 
family are scattered throughout the genome, with the exception of one 
'cluster' of 4 genes localized within a 2-3 map unit region on 
chromosome IV.  Evidence from phage and cosmid clones also indicates 
that most genes are widely separated.  The times of transcription 
throughout the life cycle have been determined for about 20 genes by 
Northern blot analysis and by probing cloned genes with labeled, stage-
specific cDNA's.  Several different patterns of transcription are seen,
but the genes can be roughly grouped into four categories based on 
the stages during which they are transcribed.  Location in the genome 
does not appear to be important for the control of transcription since 
genes with the same pattern of expression are found on different 
chromosomes, while genes within the 'cluster' on chromosome IV have 
different expression patterns.  We are therefore pursuing the idea 
that the different patterns of transcription are controlled by 
specific regulatory sequences that lie near or within each gene.
We reported the DNA sequences of two collagen genes, col-1 and col-2,
earlier (Kramer et al.  (1982) Cell 30, 599).  We have found that col-
1 and col-2 are transcribed with different temporal patterns and we 
have recently analyzed their transcripts using S1 nuclease digestion 
mapping.  We have found that both transcripts begin approximately 30 
nucleotides before the initiator methionine codon and end 
approximately 12 nucleotides beyond the AATAAA poly-A addition signals.
Major homologies in the 5 - upstream region are: an 8 nucleotide 
stretch at the start of each transcript that may be a ribosome 
recognition sequence, 8 nucleotides that include the 'TATAA' box, and 
a repeated sequence (TTTCCAGT) ,found between nucleotides 200 to 300 
in both collagen genes and also in an MSP gene cloned by M.  Klass.  
We are intrigued to know whether this repeated sequence has any 
special transcriptional functions.  We currently are completing the 
sequences of 5 more collagen genes so that sequence comparisons can be 
made among with genes having different patterns of expression.