Absence of Syk and ZAP-70 but normal expression of Src-family kinases in syk^−/− neutrophils.

Lysates of wild-type (WT) and syk^−/−(Syk KO) neutrophils were probed for the presence of Syk and ZAP-70 (A) or Syk and the Src-family kinases Hck, Fgr, and Lyn (B) by immunoblotting with the appropriate antibodies. Lysates of wild-type thymocytes and ofhck^−/−fgr^−/−lyn^−/−(Src-family KO) neutrophils were included as controls. The bottom panel shows equal amount of actin in the different lysates. PMN indicates polymorphonuclear leukocyte.