Methylation patterns in bovine satellite I DNA were studied by direct sequence analysis. Satellite I DNA was prepared as a discrete restriction fragment from genomic DNA of various bovine tissues and subjected to sequencing by the technique of Maxam and Gilbert. Sequence was obtained for a region of 350 nucleotide pairs in the satellite fragments from calf thymus and bull sperm DNA's. Comparison of sequence ladders from methylated and unmethylated DNA's (thymus and sperm, respectively) facilitated identification of methylated cytosines. / Methylation in thymus DNA was shown to be confined to the configuration 5' ('m)CpG 3', and there was no indication that these sites were methylated in the sperm sequence. In thymus DNA, there were a few occurrences of the CpG doublet in which cytosines were apparently not methylated. In regions where sequence was obtained for both strands, methylation was shown to be symmetrical. When the analysis was extended to DNA from other tissues, the unmethylated pattern was demonstrated only in chorion DNA. All other tissues showed the thymus methylation pattern. / Sequence was also obtained from a cloned satellite I fragment. This sequence was compared by computer with sequence from genomic DNA and with other known bovine satellites. A computerized homology search demonstrated degenerate repetitions within the satellite I sequence and degenerate homologies with other bovine satellites. / The results are discussed in light of other recent findings, and in terms of their possible implications for evolution and development. / Source: Dissertation Abstracts International, Volume: 42-12, Section: B, page: 4681. / Thesis (Ph.D.)--The Florida State University, 1982.
|MCGRAW, ROYAL ALFRED, III., Florida State University
|Florida State University
|On campus use only.
|Dissertation Abstracts International
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