Showing papers by "Richard A. Flavell published in 1978"
TL;DR: A restriction map of the human beta--and delta-globin genes and the surrounding genomic DNA regions has been constructed and the structure of the Hb Lepore gene is shown to be a fused delta--and beta- globin gene, and to be completely consistent with the derived map of normal beta-- and delta- Globin genes.
220 citations
TL;DR: Cloned β-globin genes of both mouse and rabbit each contain a large and a small intervening sequence (intron) of about equal length at precisely the same positions relative to the coding sequence.
Abstract: Cloned β-globin genes of both mouse and rabbit each contain a large and a small intervening sequence (intron) of about equal length at precisely the same positions relative to the coding sequence The homologous introns show some sequence similarity, particularly at the junctions with the coding sequence They most probably arose from a common ancestral sequence and diverged substantially during evolution
135 citations
TL;DR: Analysis of the linear organisation of the large proportion of repeated sequence DNA as well as the non-repeated DNA in the wheat and rye genomes has enabled schematic maps to be drawn which show how the repeated and non- Repeated sequences are arranged in the Wheat and Rye genomes.
83 citations
TL;DR: The results suggest that the lack of thyroglobulin in these goiters is due to a defect in thyroblobulin mRNA which leads to aberrant processing and/or transport of it from its site of synthesis to the endoplasmic reticulum.
Abstract: The goiters in a breed of hypothyroid goats contain only minute amounts of thyroblobulin-related antigens (0.01% of normal value). We have analyzed these goiters for the presence of mRNA coding for thyroglobulin. Using DNA complementary to beef 33S thyroglobulin mRNA as a probe, we found that the mRNA sequence is present in the goat goiter but at a concentration 1/10-1/40 that of normal goat thyroid. Hybrids of cDNA with either goiter or normal thyroid RNA exhibited identical sharp melting curves which suggests that the same RNA sequence is responsible for hybridization in both tissues. Normal goat thyroid contains a population of large membrane-bound polysomes engaged in throglobulin synthesis. In contrast, such polysomes are absent in the goiter. In regard to subcellular distribution, the relative amount of the thyroglobulin mRNA sequences from the goiter in nuclear RNA was 42% of normal, in cytoplasmic RNA was 7% of normal, and in the membrane fraction was only 1-2% of normal. Our results suggest that the lack of thyroglobulin in these goiters is due to a defect in thyroglobulin mRNA which leads to aberrant processing and/or transport of it from its site of synthesis to the endoplasmic reticulum.
42 citations
6 citations
01 Jan 1978
5 citations
TL;DR: It is found that the viral DNAs PM2, lambda and SV40 contain at least 1, 1 and 2 sites for binding to poly(rC)-Sephadex, respectively; these binding sites have been mapped in the case of SV40 and can be used for physical mapping studies of DNAs containing (dG.dC) clusters.
Abstract: Duplex DNA containing oligo(dG.dC)-rich clusters can be isolated by specific binding to poly(rC)-Sephadex. This binding, probably mediated by the formation of an oligo(dG.dC)rC+ triple helix, is optimal at pH 5 in 50% formamide, 2 M LiCl; the bound DNA is recovered by elution at pH 7.5. Using this method we find that the viral DNAs PM2, lambda and SV40 contain at least 1, 1 and 2 sites for binding to poly(rC)-Sephadex, respectively. These binding sites have been mapped in the case of SV40; the binding sites can in turn be used for physical mapping studies of DNAs containing (dG.dC) clusters. Inspection of the sequence of the bound fragments of SV40 DNA shows that a (dG.dC)6-7 tract is required for the binding of duplex DNA to poly(rC)-Sephadex. Although about 60% of rabbit DNA cleaved with restriction endonuclease KpnI binds to poly(rC)-Sephadex, no binding is observed for the 5.1 kb DNA fragment generated by KpnI digestion, which contains the rabbit beta-globin gene. This indicates that oligo(dG.dC) clusters are not found close to the rabbit beta-globin gene.
4 citations
3 citations