Evolutionary conservation and molecular cloning of the recombinase activating gene 1.
A 700-bp fragment of the recombinase activating gene 1 (RAG-1) was cloned from several evolutionarily distant (sandbar shark, paddlefish, goldfish, axolotl and pig) species using PCR. The nucleotide and deduced amino acid sequences revealed a highly conserved region that has remained essentially unaltered during 400 million years of evolution; e.g., shark and human sequences were 75% identical at the nucleic acid level and 87% as protein. The RAG-1 mRNA levels in the shark were analyzed using semi-quantitative PCR to reveal expression patterns contrary to normal mammalian expression. These results establish that the genetic mechanisms for Ig gene rearrangement are present in all extant gnathanstomes.
Bernstein
R M
RM
College of Medicine, University of Arizona, Tucson 85724.
Schluter
S F
SF
Lake
D F
DF
Marchalonis
J J
JJ
D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D003001:Cloning, Molecular; D017124:Conserved Sequence; D016654:Genes, RAG-1; D006054:Goldfish; D006801:Humans; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D012754:Sharks; D013154:Spleen / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism