Cell-type-specific expression of a TESK1 promoter-linked lacZ gene in transgenic mice

Testicular protein kinase 1 (TESK1) is a serine/threonine kinase highly exp ressed in testicular germ cells and has the potential to phosphorylate cofi lin and induce actin cytoskeletal reorganization. We examined the expressio n of a lacZ reporter gene linked to a 9.0-kb 5'-flanking region of TESK1 ge ne in transgenic mice. A high level of lacZ expression was observed in test icular germ cells only at stages after pachytene spermatocytes, the express ion patterns being similar to those of TESK1 mRNA in rat testis, determined by in situ hybridization. Expression of lacZ was also detected in renal pr oximal tubules, cardiac myocytes, and specific neurons in the central nervo us system in adult transgenic mice. Whole-mount staining revealed the expre ssion of lacZ in neural tissues in embryonic mice. These results suggest th e cell-type- and stage-specific expression of TESK1 gene and the diverse an d specific physiological functions of TESK1, including those in spermatogen esis and neural development. (C) 2001 Academic Press.