Expression of β-galactosidase and eotaxin in different tissues in eotaxin^+/− mice. (A) Expression of β-galactosidase detected by X-gal staining. Frozen tissue sections from wild-type (+/+) and heterozygous (+/−) mice were stained with X-gal overnight and counter-stained with eosin. Shown are the tissues with strong β-galactosidase staining. (B) Expression of eotaxin and fic in different tissues detected by RT-PCR. Total RNA was isolated from eotaxin heterozygous and null mice and amplified by RT-PCR with primers specific for mouse eotaxin, fic, or β-actin. (C) Costaining of X-gal with CD34 markers in lymph nodes and small intestine. Frozen sections were stained with X-gal overnight, followed by immunohistochemical staining with anti-CD34 antibody and then counter-stained with eosin as described in Materials and Methods. The blue staining illustrates the β-galactosidase activity and the brown staining is for CD34 marker.