Showing papers by "Carl W. Schmid published in 1984"
TL;DR: Most of the highly repetitive (greater than 50,000 copies) human interspersed repeats have already been identified, and the bulk of the in vivo transcriptional activity of these repeats appears to be nonspecific read through from other promoters.
Abstract: Randomly selected human genomic clones have been surveyed for the presence of non-Alu family interspersed repeats. Four such families of repeats have been isolated and characterized with respect to repetition frequency, interspersion, base sequence, sequence divergence, in vitro RNA polymerase III transcription, elongation of transcripts in isolated nuclei, and in vivo transcription. The two most abundant of the four families of repeats correspond to previously reported families of repeats, namely the kpn I family and poly (CA). We conclude that most of the highly repetitive (greater than 50,000 copies) human interspersed repeats have already been identified. Two lower abundance repeats families are also described here. The abundance with which each of these families is represented in nuclear RNA qualitatively corresponds to their genomic reiteration frequencies. Further, the complementary strands of each repeat family are approximately symmetrically transcribed. The abundance of these repeats in cytoplasmic RNA is qualitatively less than in nuclear RNA. The bulk of the in vivo transcriptional activity of these repeats thus appears to be nonspecific read through from other promoters.
110 citations
TL;DR: The nucleotide sequences of the two 5'-homology blocks of human alpha-globin gene duplication units were determined and provide the physical evidence for polar gene correction process in a mammalian genome.
Abstract: The nucleotide sequences of the two 59-homology blocks of human alpha-globin gene duplication units were determined. The sequence difference between the two blocks is essentially zero in the 59 portions, and increases gradually toward the 39 ends until it reaches a value of 18 percent. This gradient of sequence divergence is similar to the distribution of the frequencies of gene conversion along several loci in Ascobolus and yeast. Hot spots for initiation of gene correction processes appear to exist near the 59 ends of the human alpha-globin duplication units. The data provide the physical evidence for polar gene correction process in a mammalian genome.
54 citations