Endogenous retrovirus HC2 pol fragments in the squirrel monkey: expression, evolution, and phylogeny.
Human endogenous retrovirus HC2 is an incomplete provirus containing the entire gag and pol genes and a 3' LTR, whereas the 5' LTR and env gene are missing. We investigated expression of the HC2 pol gene in the squirrel monkey ( Saimiri sciureus) by RT-PCR. The pol gene was expressed in cerebellum, liver, lung, and spleen of the squirrel monkey, but not in six other tissues tested. RT-PCR products were cloned and sequenced resulting in seven sequences that were analyzed. These sequences showed 73.7-89.2% sequence similarity to HC2 pol genes present in the human genome. No frameshifts or termination codons caused by deletion/insertion or point mutation were found in clones SM-HC27-1 and SM-HC27-4 isolated from squirrel monkey lung tissues. Phylogenetic analysis showed that HC2 pol elements from the squirrel monkey were randomly clustered with those in human genome and the genomes of other nonhuman primates, indicating that substantial evolution of the HC2 elements occurred prior to primate speciation with additional evolution of the elements, independent of each other, after speciation.
Division of Biological Sciences, College of Natural Sciences, Pusan National University, Pusan, Korea.
J-M
JM
Yi
T-H
TH
Kim
J-I
JI
Huh
S
S
Nakamura
O
O
Takenaka
W-H
WH
Lee
B-H
BH
Hyun
H-S
HS
Kim
D000595:Amino Acid Sequence; D000818:Animals; D020077:Endogenous Retroviruses / Q000145:classification / Q000235:genetics*; D015750:Genes, gag; D015751:Genes, pol; D008969:Molecular Sequence Data; D010802:Phylogeny; D012453:Saimiri / Q000821:virology*; D020079:Terminal Repeat Sequences