Book excerpt: Guide to Techniques in Mouse Development, Part A comprehensively covers new technologies and methodologies that have appeared for the study of mouse development. - Update of volume 225 of Methods in Enzymology, Guide to Techniques in Mouse Development, edited by P.M. Wassarman and M.L. DePamphilis and published in 1993 - Covers new technologies and methodologies, including: - new techniques for the cryopreservation of gametes and embryos - production of transgenic and null (knockout) animals (use of ES cells) - generation of conditional/inducible mutant animals - use of gene-trap mutagenesis - analysis of allele-specific expresion - use of new reporter constructs - humanizing of transgenic animals - transcript profiling of mouse development - imaging of mouse development - rederivation of animals and use of mouse genomics