Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 66-72).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Th.--Sci. nat.--Lille 1, 1977. N°: 382. / Extr. en partie de Biochimica et biophysica acta, 342, 1974, 360-366 et de F.E.B.S. Letters, 65, 1976, 2, 225-228.

The basic protein composition of sperm, as well as the change in basic proteins during spermiogenesis, has been studied in a number of organisms, using both cytochemical and biochemical techniques. The sperm of the seven anurans studied are divided on cytochemical criteria into three of the five classes proposed by Bloch (1969). Rana palustris and R. pretiosa are of the Rana type. Xenopus laevis, Hyla versicolor, and H. regilla are of the Mytilus type while Bufo americanus and B. boreas appear to be of the Salmon type. Electrophoresis of testicular histones from representatives of these three types reveals significant differences. Testis specific components are absent in R. pipiens. In laevis, three testis specific bands, migrating between salmon protamine and the somatic histones, are present. A testis specific band migrating close to salmon protamine is found in B. americanus. The basic protein changes during spermiogenesis in the eastern red spotted newt, Diemictylus viridescens, resemble the transitions described in the snail, Helix aspera, (Bloch and Hew 1960a), the squid, Loligo opalescens (Bloch 1962) and Pleurodeles waltii (Picheral 1970). The early stages of spermiogenesis contain somatic type histones which in later spermatids are replaced by the Mouse/grasshopper type of protein. In turn, these proteins are replaced by the Salmon type of protein in the spermatozoa. Electrophoresis of testicular histones of the newt supports the cytochemical events outlined. Two testis specific bands are found. Spermiogenesis in three cartilaginous fish (dogfish, skate and ratfish) is characterized by unusual changes in basic proteins. Early spermatids contain somatic type histones. However, late spermatids contain the Salmon type of sperm histone while spermatozoa contain the Mouse/grasshopper type. Electrophoresis of testicular histones indicates that protamines are present in elasmobranch testes. However, a Mouse/grasshopper type of protein is not revealed. / Science, Faculty of / Zoology, Department of / Graduate

Nucleosomes were prepared from trout testis nuclei by micrococcal nuclease digestion. The reactivity toward N- [ethyl- ³Hlmaleimide (NEM) of the single sulfhydryl group of histone H3 in the nucleosomes was studied under a variety of conditions. Under conditions of low ionic strength, there is negligible reaction of nucleosomes with NEM, suggesting that the cysteinyl residue of H3 is buried. Complete denaturation of nucleosomes in 6 M guanidinium chloride leads to reaction of 2 moles of NEM per mole of nucleosomes, in agreement with the expected presence of 2 moles of H3 per particle. Exposure of nucleosomes to 2 M NaCI or 1 M MgCl₂ leads to exposure of the thiol group. At higher Mg⁺⁺ concentrations, the thiol group remains exposed, but in NaCI solutions, as the salt concentration is increased beyond 2 M, the thiol group returns to an inaccessible state. The reactivity of nucleosome thiol groups is relatively unaffected by urea to approximately 5 M. Between 5 and 8 M urea, a rapid increase in thiol reactivity indicates a cooperative unfolding of the nucleosome core. When added together, urea and salt act in a cooperative manner to expose the H3 sulfhydryl group. Mixtures of oligonucleosomes have also been studied under different conditions. They were found to behave in a similar fashion to monomers in 6 M guanidine, but their thiols react more slowly than those of monomers in high salt. Removal of the amino-terminal regions of the core histones by tryptic digestion has no noticeable effect on the accessibility of nucleosome thiol groups. It is concluded that the carboxy-terminal region of H3 containing Cys 110 is masked mainly by histone-histone interactions in the octameric core complex, and is located in a region which is relatively insensitive to the perturbations induced by trypsin or low concentrations of urea. Nucleosomes reconstituted in the presence of a sulfhydryl reducing agent were indistinguishable from native particles in their reactivity to NEM in low salt buffers, in 2 M NaCl and in 6 M guanidine hydrochloride. These studies indicate that the degree of exposure of H3 sulfhydryl groups in nucleosomes can be effectively monitored using NEM. The carboxy-terminal region of H3 containing Cys 110 seems to be located in a relatively stable region of the nucleosome core, perhaps at the interface between heterotypic tetramers. / Medicine, Faculty of / Biochemistry and Molecular Biology, Department of / Graduate

Histones have been described by Murray (1964) as basic nuclear proteins which are at some time associated with DNA. Reviews on the biochemistry of histones have been written by Phillips (1962), Busch (1965 ), Butler, Johns and Phillips (1968), Hnilica (1967) and Bonner, Dabrnus, Fambrough, Huang, Marushige and Tuan (1968). These proteins are at present the subject of considerable interest because they are probably involved in the permanent repression of part of the genetic information of the DNA. If this is so, they must be basically involved in the control of cell differentiation.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Virginia, 2006. / Spine title: Transcription by the SAGA complexes. Includes bibliographical references. Also available online through Digital Dissertations.

This thesis investigated the helical structure of core histone octamers to discover interacting surfaces and their relevance to the compaction of nucleosome arrays into the chromating fiber.