Collis, P.

expression globin number level copy number mouse hypersensitive fetus copy numbers b-globin result position sites 2 site 2 site 3 activity grosveld acids research liver rna mosaic region fragment site 1 placental dna microlocu hypersensitive sites deletion liver transgene copy number copy number dependence probe mosaic mice site 4 gene copy research position independence 3- globin b-globin gene level expression mel cells control table transgenic assay analysis nuclease u.s.a control region b-globin microlocus cassette site 4 transgenics transgene hypersensitive site locus dna fragments independence laboratory 3- globin gene mel cell populations table i deboer antoniou 13.5 tissue sample greave placental presence integration placenta talbot 13- globin element sites 1 exogenous gene mutant expression levels hybridized population gene therapy vector sequences