CDNA LIBRARIES FROM IDENTIFIED NEURONS

One approach to studying the changes in gene expression which underlie differentiation is to construct cDNA libraries from different tissues or at different stages of development. However, generating representa tive cDNA libraries from heterogeneous tissues such as the nervous sys tem is often a real problem. Here, we describe a reproducible method f or the construction of large and complex cDNA libraries from a few lee ch Retzius or P neurons (equivalent to about 50 pg of mRNA) using poly merase chain reaction-based technology. The libraries contain about 10 (6) independant recombinants and are remarkably free from contaminatin g rRNA or polymerase chain reaction artefacts. Sequence analysis of ra ndomly picked clones shows that the libraries contain a high proportio n (more than 90 %) of cDNAs larger than 500 b.p. As expected, many of the clones are novel, but two (alpha-tubulin and cyclophilin-A) have b een extensively characterized in other species. To our knowledge, this is the first report of a cDNA library from identified neurons.