THE LACTATE-DEHYDROGENASE GENE FROM NEMATODE CAENORHABDITIS-ELEGANS CONTAINS ONLY 2 OF 6 INTRONS CONSERVED IN THE PROTEIN-ENCODING SEQUENCEOF LDH GENES FROM BIRD AND MAMMALS

The protein-encoding region of L-lactate dehydrogenase (LDH) gene from nematode, Caenorhabditis elegans, was amplified by polymerase-chain-r eaction from total genomic DNA and its nucleotide sequence determined. A comparison of this genomic sequence with the published sequence of nematode LDH cDNA reveals the presence of two introns of 57 and 47 nuc leotides at codon no. 82 and 279-280, respectively. The positions of t he two introns present in this invertebrate LDH gene correspond to the second and sixth introns of vertebrate LDH genes. The protein-coding sequence of human LDH-A (muscle),LDH-B (heart) and LDH-C (testis), mou se LDH-A, and duck LDH-B genes has previously been shown to be interru pted by six introns at the homologous positions.