MEDIUM WEIGHT NEUROFILAMENT MESSENGER-RNA IN GOLDFISH MAUTHNER AXOPLASM

Although axons are generally considered to lack the ability to synthes ize proteins, the Mauthner axon (M-axon) of the goldfish has been repo rted to contain some of the basic components of the translational mach inery, such as transfer RNA (tRNA), ribosomal RNA (rRNA), and ribosome s. To determine if the M-axon also contains mRNA, we isolated samples of M-axoplasm free of glial contamination as demonstrated by the absen ce of glial-specific mRNA and protein. Reverse transcription-polymeras e chain reaction (RT-PCR) of M-axoplasmic cDNA in the presence of prim ers for the goldfish medium-weight neurofilament (NF-M) gene produced a single product of the expected length for RT-PCR amplification of go ldfish NF-M mRNA. This mRNA might direct protein synthesis of NF-M wit hin the M-axoplasm.