Artículos de revistas
Coexistence of two chromatin structures in sperm nuclei of the bivalve molluscProtothaca thaca
Registro en:
Molecular and Cellular Biochemistry 125 (1): 87-95
0300-8177
Autor
Olivares, C.
Vera, M.L.
Ruíz Lara, Simón
Institución
Resumen
Ruiz Lara, S. Departamento Ciencias Biológicas, Universidad de Talca, Talca, Chile. The chromatin of the spermatozoa from the bivalve molluscProtothaca thaca, has a peculiar composition in which coexist core histones with sperm-specific proteins H1 and Pt1, the latter being a protein exhibiting features intermediate between histones and protamines. In this paper, we report an analysis of chromatin organization using micrococcal nuclease digestion, salt fractionation of soluble chromatin derived from nuclease digestion and crosslinking experiments. The results obtained indicate that it is possible to obtain two types of chromatin, one which is soluble, more accessible to micrococcal nuclease action and which does not contain Pt1, and another insoluble type, more resistant to micrococcal nuclease and enriched in protein Pt1. The crosslinking experiments show that the protein Pt1 interacts with itself and with core histones but not with sperm-specific H1. These results have led us to propose a special structural arrangement for this chromatin. Based in the data reported here we propose the coexstence in the genome ofP. thaca of two interspersed chromatin domains, one nucleosomal and the other nonnucleosomal containing protein Pt1.