The minisatellite of the GPI/AMF/NLK/MF gene: interspecies conservation and transcriptional activity

Minisatellites are tandemly repeated DNA sequences found throughout the gen omes of all eukaryotes. They are regions often prone to instability and hen ce hypervariability; thus repeat unit sequence is generally not conserved b eyond closely related species. We have studied the minisatellite located in intron 9 of the human glucose phosphate isomerase (GPI) gene (also known a s neuroleukin, autocrine motility factor, maturation and differentiation fa ctor) and have found, by Zoo blotting coupled with PCR amplification and DN A sequencing, that similar repeat units are present in seven other species of mammal. There is also evidence for the presence of the minisatellite in chicken. The repeat unit does not appear to be present at any other locus i n these genomes. Minisatellite DNA has been reported to be involved in reco mbination activity, control of gene expression of nearby gene(s) (both tran scriptional and translational), whilst others form protein coding regions. The high level of conservation exhibited by the GPI minisatellite, coupled with the unique location, strongly suggests a functional role. Our results from transient and stable transfections using luciferase reporter construct s have shown that the GPI minisatellite region can act to increase transcri ption from the SV40 promoter, CMV promoter and the human GPI promoter. (C) 2001 Elsevier Science B.V. All rights reserved.