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M G Romanini

Publications and source records attributed to M G Romanini.

6 recordsLinked to original sources
PubMed1995

Study of genome organization by DNA cytochemistry and fluorescence imaging: a review.

DNA analysis by quantitative cytochemistry has been a widely exploited approach to investigate chromatin superstructural changes in relation to cell function and cell cycle progress. To this aim, a number of dyes (especially fluorochromes) for nucleic acids have been used, exhibiting different peculiarities, in terms of both binding mechanism and base specificity. Less attention has been paid to the application of different DNA staining techniques for studying possible differences in genome organization among different taxa. The purpose of this paper is to review and discuss the present reports in the literature, concerning the cytochemical analysis of genome organization, in a comparative perspective. Special attention is given to the integration of quantitative studies based on cytofluorometric and imaging techniques.

Animals↗
PubMed1992

Immunoelectron microscopical distribution of histones H2B and H3 and protamines in the course of mouse spermiogenesis.

We have followed the fine structural distribution of two nucleosomal core histones, H2B and H3, and of protamines in the course of mouse spermiogenesis by means of specific antibodies and ultrastructural immunocytochemistry. Our results demonstrate that the nuclear labeling density of histone H2B decreases during steps 6-8 and then increases again in step 9-10 spermatids, while the labeling for histone H3 is constant throughout this period. In step 12 spermatids, the anti-H2B antibody labels mainly the central area of the nucleus. The first signs of protamine labeling are present in step 12 spermatids, where the gold grains can be found over the periphery of the nucleus. Later on, protamine labeling constantly increases and, by the end of spermiogenesis, the whole nucleus is labeled. We suggest that the morphological and structural differences between the central area and the periphery of mouse spermatids are, at least partly, due to a difference in the protein moiety associated with DNA. The central area, which is peculiar to the mouse and has been previously considered as a focus of chromatin condensation, represents, however, the last nuclear region containing histones and consequently the last area where the substitution of histones by protamines takes place.

Animals↗
PubMed1991

Proliferating cell nuclear antigen (PCNA)/cyclin expression during the cell cycle in normal and leukemic cells.

Bivariate flow cytometric analysis of the cell proliferation-associated nuclear protein, identified as the "proliferating cell nuclear antigen" (PCNA)/cyclin and of nuclear DNA content, was performed in quiescent and mitogen-stimulated human peripheral blood lymphocytes, in EUE (human embryonic epithelium) cells, before and after a long-term exposure to a hypertonic (HT) medium, in 4 human leukemic cell lines and in fresh bone marrow (BM) cells from 10 patients with untreated acute non-lymphoblastic leukemia (ANLL). The PCNA/cyclin was detected using both an autoantibody extracted from sera of systemic lupus erythematosus patients and the recently produced mouse monoclonal antibody (MoAb) IgG, named 19F4. The distribution of cells in the different phases of the cycle and the percentage of S-phase cells were obtained in duplicate samples, by DNA flow cytometry (FCM) and by dual parameter FCM of DNA content and bromodeoxyuridine (BUDR) incorporation. In all cell types, the non-specific cytoplasmic background fluorescence was significantly lower with the MoAb compared to that obtained with the polyclonal Ab. The percentage of PCNA-positive cells (both with the autoantibody and the 19F4 MoAb) was always higher than that of S-phase cells by DNA FCM and of BUDR-labeled cells. The pattern of PCNA-expression in both normal proliferating cells and acute leukemia cells, showed that most G0/G1 cells did not express significant amounts of PCNA; an increase in PCNA immunofluorescence was found in late G1 cells, and further increases were observed in S- and G2-M phase cells. PCNA/cyclin, as revealed both with autoantibodies and with the 19F4 MoAb, is associated with all actively or potentially dividing (i.e. G1, S and G2-M) cells thus identifying the proliferative cellular compartment. Combined with the use of multiparameter FCM techniques, the PCNA immunolocalization offers a useful tool to study cell kinetics in normal and leukemic human cell populations.

Antibodies, Monoclonal↗