Expression of RNase9 (A) Tissue distribution of RNase9 . The indicated tissues were analyzed for RNase9 mRNA levels (550 bp) by RT-PCR. RNA (2 ug) from various tissues and different parts of the human epididymis was reverse-transcribed and analyzed by RT-PCR.RNase9 was expressed in all the tissues: epididymis, heart, lung, liver, spleen, kidney, stomach, and testis except muscle (negative control). β-actin (580 bp) served as an internal control. (B) RNase9 expression in epididymis. RT-PCR analysis of RNase9 mRNA levels (550 bp) in human epididymal tissues. Human epididymis tissues were collected from fetus, adult, and older individuals. β-actin (580 bp) served as an internal control.