Eotaxin and CCR-3 mRNA expression in embryonic tissues. RT products were prepared from RNA isolated from frozen tissues. Briefly, 1 μg of total RNA was reverse transcribed, and equalized amounts of the cDNA generated were amplified with β-actin (20 cycles), eotaxin (30 cycles), and CCR-3 (32 cycles) primers to generate fragments of 348, 108, and 454 bp, respectively. Adult tissues (A) were used as a control.