Deoxyribonuclease I sensitivity of the ovomucoid-ovoinhibitor gene complex in oviduct nuclei and relative location of CR1 repetitive sequences.
The location of CR1 middle repetitive sequences within or near the boundaries of the ovalbumin DNase I sensitive domain has suggested that CR1 sequences may play a role in defining transition regions of DNase I sensitivity in hen oviduct nuclei. We have examined this apparent relationship of CR1 sequences and transitions of chromatin structure by determining the DNase I sensitivity in oviduct nuclei of a 47-kilobase region that contains five CR1 sequences and the transcribed ovomucoid and ovoinhibitor genes. We find that three of the CR1 sequences occur within a broad transition region of decreasing DNase I sensitivity downstream of the ovomucoid gene. Another CR1 is in a region of decreased DNase I sensitivity within the ovoinhibitor gene. The fifth CR1 sequence is in a DNase I sensitive region between the two genes but which is less sensitive to DNase I digestion than the region immediately upstream from the ovomucoid gene. Thus, the CR1 sequences occur within regions of reduced relative DNase I sensitivity, suggesting that CR1s could facilitate the formation of a chromatin conformation that is less sensitive to DNase I digestion. Unexpectedly, the noncoding strand of sequences within and immediately adjacent to the 5' end of the actively transcribed ovomucoid and ovalbumin genes was less sensitive to DNase I digestion than their respective coding strands.
Scott
M J
MJ
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
Tsai
M J
MJ
O'Malley
B W
BW
D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D002645:Chickens; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D003850:Deoxyribonuclease I / Q000378:metabolism*; D004527:Egg Proteins / Q000235:genetics*; D005260:Female; D005796:Genes / Q000187:drug effects; D007700:Kinetics; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010057:Oviducts / Q000378:metabolism*; D010059:Ovomucin / Q000037:antagonists & inhibitors / Q000235:genetics*; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000235:genetics*; D014361:Trypsin Inhibitors / Q000235:genetics*
D004527:Egg Proteins; D014361:Trypsin Inhibitors; C039345:ovomucoid inhibitors; D010059:Ovomucin; D014359:Trypsin Inhibitor, Kazal Pancreatic; D004262:DNA Restriction Enzymes; D003850:Deoxyribonuclease I