RANDOM RAPID AMPLIFICATION OF CDNA ENDS (RRACE) ALLOWS FOR CLONING OFMULTIPLE NOVEL HUMAN CDNA FRAGMENTS CONTAINING (CAG)(N) REPEATS

We describe a new technique for isolating cDNA fragments in which (i) either a partial sequence of the cDNA is known or (ii) a repeat sequen ce is utilized. We have used this technique, termed random rapid ampli fication of cDNA ends (random RACE), to isolate a number of trinucleot ide repeat (CAG)(n)-containing genes. Using the random RACE (RRACE) te chnique, we have isolated over a hundred (CAG)(n)-containing genes. Th e results of our initial analysis of ten clones indicate that three ar e identical to previously cloned (CAG)(n)-containing genes. Three of o ur clones matched with expressed sequence tags, one of which contained a CA repeat, The remaining four clones did not match with any sequenc e in GenBank. These results indicate that this approach provides a rap id and efficient method for isolating trinucleotide repeat-containing cDNA fragments, Finally, this technique may be used for purposes other than cloning repeat-containing cDNA fragments, If only a partial sequ ence of a gene is known, our system, described here, provides a rapid and efficient method for isolating a fragment of the gene of interest.