Identification of a cDNA for medaka cytoskeletal beta-actin and construction for the reverse transcriptase-polymerase chain reaction (RT-PCR) primers

A full-length cDNA for medaka cytoskeletal beta-actin was isolated from a liver cDNA library. The entire coding region was 1125 bp long and was well conserved with respect to other vertebrate beta-actins. Two primers for a reverse transcriptase-polymerase chain reaction (RT-PCR) assay were constructed from the nonvariable region among medaka, carp, chicken, and mouse beta-actin. RT-PCR amplified a 510 bp DNA band from medaka cDNA synthesized from the blood, brain, heart, intestine, kidney, liver, muscle, ovary, spleen, and testis poly(A)+mRNA. The constructed primers were used successfully to detect a specific 510 bp fragment of beta-actin from zebrafish, rainbow trout, and Japanese flounder.