Worm Breeder's Gazette 12(2): 16 (January 1, 1992)

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.

C. elegans cDNA Expression Libraries in lambda gt11

Peter Okkema, Verena Plunger, Andrew Fire

Figure 1

Carnegie Institution of Washington, Department of Embryology, 115 W. University Parkway, Baltimore, MD 21210.

We have made cDNA libraries in lambda gt11 using RNA from C. elegans embryos or mixed-stage hermaphrodites. The cDNA was primed with oligo-(dT) and cloned into the EcoRI site of lambda gt11 using adaptors containing EcoRI, BamHI, KpnI, and NcoI restriction sites. The average insert size is 1.1kb for the embryonic library and 1.7kb for the mixed-stage library. Approximately 10+E6 recombinant phage were amplified from each library, and aliquots of the amplified libraries are available from us.

These libraries have not yet been extensively characterized. However, many clones encoding unc-54 enhancer binding proteins were isolated in an initial screen (see abstract by Plunger and Fire). During this work we noticed many clones do not have an EcoRI site within the adaptor. While this does not present a problem in screening the library, the inserts may have to be subcloned using other restriction enzymes.

We have previously screened several other C. elegans expression libraries. When using a library purchased from Clontech Laboratories (Palo Alto, CA), we isolated a number of clones which are not encoded in the C. elegans genome and appear to be contaminating yeast cDNAs. Understandably, our advice would be to stay away from the Clontech library.

[See Figure 1]

Figure 1