Gene expression pattern during population growth of the rotifer Brachionus plicatilis

Abstract

To search for genes that are expressed during population growth of the rotifer Brachionus plicatilis in a phase-dependent manner, we carried out mRNA arbitrarily primed reverse transcription-polymerase chain reaction (RAP RT-PCR). Total RNAs were extracted from the population exponentially growing (day 10) and that in a stationary phase (day 15). cDNAs were synthesized with each of five random primers contained in RAP RT-PCR kit, and fingerprinting patterns were compared between the populations on days 10 and 15. One gene from five candidates differentially expressed was successfully cloned, and its DNA nucleotide sequence of 444 bp was determined. The deduced amino acid sequence of 130 residues showed 57-82% identity with those of clathrin heavy chain genes from various organisms including yeast and human. Northern blot analysis revealed that the accumulated mRNA levels were significantly higher in exponential than stationary phase. Thus, it seems possible to use expression patterns of the clathrin gene for monitoring the growth status of rotifer populations. © 2002, The Japanese Society of Fisheries Science. All rights reserved.