CONSERVATION OF SEQUENCES BETWEEN HUMAN AND GORILLA LINEAGES - ADP-RIBOSYLTRANSFERASE (NAD(+)) PSEUDOGENE-1 AND NEIGHBORING RETROPOSONS

The evolution of ADP-ribosyltransferase (NAD(+)) pseudogene 1 (ADPRTP1) was studied among higher primates. When the human pseudogene was used to probe genomic DNA from chimpanzee, gorilla, macaque, howler monkey and lemur, a fragment from gorilla produced the most intense hybridization signal. The resultant hybridization pattern indicated a modified pseudogene structure in these primates relative to the human and gorilla loci. Sequence comparison of this new DNA locus (ADPRTP1 and surrounding retroposons) showed a nucleotide (nt) identity of 98.13% (over 5.8 kb) between the genomic regions of human and gorilla, A unique duplicated region of 30 base pairs (bp) was found in gorilla ADPRTP1, separate from the duplicated region (193 bp) responsible for the restriction-fragment length polymorphism (RFLP) previously reported in humans, and which appeared to represent a marker for a predisposition to cancer. An endogenous pol (gene encoding polymerase) related element that flanked the human pseudogene was used as a probe to identify a fragment from this retroviral family in New World monkeys. Altogether, analysis of these retroposons will provide an opportunity for future studies on the molecular phylogenetic relationship of higher primates.