(A) Northern blot analysis of Desrt mRNA expression showing a transcript of ∼9 kb in poly(A)⁺ RNA isolated from adult mouse organs. GAPDH was used as a loading control. (B) RT–PCR of Desrt mRNA expression in adult mouse organs. PCR reactions were carried out in the absence of DNA (PCR H₂O), or by use of cDNA samples that had been prepared from total RNA in the presence (+) or absence (−) of reverse transcriptase. (Top) RT–PCR amplification of a 619-bp fragment of Desrt on an ethidium bromide-stained agarose gel. Southern blot hybridization of the Desrt PCR fragments by use of an internal oligonucleotide (mDesrt7) was performed (middle). (Bottom) RT–PCR amplification of a 284-bp fragment of GAPDH as a positive control.