Degree Name

PhD (Doctor of Philosophy)

Program

Biomedical Sciences

Date of Award

December 1984

Abstract

The KpnI, 1.2 and 1.5 kb families of interspersed repetitive DNAs from the African green monkey genome were isolated and characterized. Each family contains three populations of segments based on their sequence lengths and susceptibility to cleavage by the restriction enzymes KpnI and RsaI. The first population contains the smallest segments which are susceptible to both KpnI and RsaI cleavage and have fragment lengths of 1.2 kb (1.2 kb family) and 1.5 kb (1.5 kb family) respectively. The members in this population are referred to as KpnI-sensitive segments. The second population contains longer segments (> 2 kb) which represent fusions of members from different families. The fusion sequences are cleaved by KpnI at their termini but lack internal KpnI sites at the junctions that join the individual component members. The third population contains members from each family that are cleaved occasionally by KpnI (KpnI-resistant segments) and remained linked to the bulk of the high molecular weight DNA. KpnI 1.2 kb, 1.5 kb and KpnI-resistant populations were isolated and analyzed for the presence of internal RsaI sites. All members from both populations were cleaved by RsaI into a simple series of low molecular weight fragments. Some members from both the KpnI-sensitive and the KpnI-resistant populations were found to contain internal RsaI sites. Other members from both populations lacked internal RsaI sites. Genomic KpnI 1.2 kb segments were cloned and two recombinants pBK(1.2)14 and pBK(1.2)39 identified. The partial nucleotide sequence of clone Kpn(1.2)14 was determined. The sequence content of KpnI 1.2 and 1.5 kb families in DNA fragments that anchor DNA loops to the nuclear matrix (att-DNA) was also studied. The relative sequence content of both 1.2 and 1.5 kb families was found to be impoverished when compared to their content in total nuclear DNA. However, members in each family were found to be present in detectable amounts. The association of KpnI 1.2 and 1.5 kb family sequences with the nuclear matrix was also demonstrated by metrizamide gradient centrifugation of nuclear matrix complexes. The results suggest that some KpnI 1.2 and 1.5 kb segments are differentially associated with nuclear proteins.

Document Type

Dissertation - unrestricted

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