DNA-binding proteins on lampbrush chromosome loops.
When fixed newt lampbrush chromosomes are treated with RNase to remove nascent transcripts and are then probed with radiolabeled single-stranded DNA in 0.1 x SSC, proteins associated with the majority of the lateral loops bind the probe nonspecifically. One or more common hnRNP proteins, several of which are known to bind single-stranded DNA, could be responsible for this generalized binding. In 1.0 x SSC only a relatively small subset of loops continues to bind the probe. In order to characterize this subset of loops, we prepared polyclonal antibodies against DNA-binding proteins initially identified by "Southwestern" analysis. We show by an in situ double labeling experiment that a polyclonal serum raised against gel-eluted histone H1 recognizes the same lateral loops that bind DNA in 1.0 x SSC.
DiMario
P J
PJ
Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21210.
Bromley
S E
SE
Gall
J G
JG
D000818:Animals; D001345:Autoradiography; D002875:Chromosomes / Q000378:metabolism*; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006657:Histones / Q000378:metabolism; D007150:Immunohistochemistry; D009673:Notophthalmus viridescens; D012261:Ribonucleoproteins / Q000378:metabolism
D015342:DNA Probes; D004268:DNA-Binding Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006657:Histones; D012261:Ribonucleoproteins