Association of transcriptionally active vitellogenin II gene with the nuclear matrix of chicken liver

Abstract

Supercoiled DNA loops linked to the nuclear matrix can be progressively cleaved with deoxyribonuclease I. The DNA which remains associated with the nuclear matrix can be purified and analysed for vitellogenin II sequence content by dot blot hybridization. Using this technique we show that vitellogenin II gene sequences are selectively associated with the nuclear matrix of liver but not with oviduct of laying hens. Following primary stimulation in immature chicks of vitellogenin synthesis with estradiol, the association of the gene with the nuclear matrix precedes vitellogenin mRNA synthesis. After 15 days when the level of vitellogenin mRNA has returned to zero, the gene is no longer preferentially associated with the nuclear matrix. At this time a second stimulation with estradiol results in a reassociation of the vitellogenin II gene with the nuclear matrix. In addition to the structural gene, both the 3' and 5' end flanking regions (1.5-2 kb) also bind to the nuclear matrix. However, beyond the limit of 1.5-2 kb upstream from the 5' end of the gene, there is no preferential binding of DNA to the nuclear matrix.