MICE LACKING A FUNCTIONAL CHK GENE HAVE NO APPARENT DEFECTS IN THE HEMATOPOIETIC SYSTEM

Non-receptor tyrosine kinase Chk has been implicated in hematopoietic development. To study the function of Chk lit vivo, we have generated chk-deficient mice using gene targeting. Overall development of mice h omozygous for this mutation was apparently normal. Blood counts, FAGS analysis of hematopoietic cell populations, CFU-C and CAFC assays shel ved no significant difference between wild type and mutant animals. Th us, the dispensability of Chk for mouse development and hematopoiesis suggests that its function may be redundant iii vivo, and most likely be compensated by activity of a closely related protein tyrosine kinas e Csk.