Genome size and DNA endoreplication pattern of non-generative cells in the antheridia of Chara connivens Salzmann ex A. Braun from Northern Morocco

Abstract

Data on nuclei, mitotic divisions, chromosomal behaviors, and DNA measurements have been examined in individuals of Chara connivens collected in a pond from the Tangier-Tetouan Region (Northern Morocco). Image Cytometry of individual nuclei was used to examine the endoreduplication level in germ line and somatic cells of the antheridia. DNA content increased from 2C up to 128C in shield cells, manubria and capitular cells. However, a progressive decrease in the amount of DNA after any successive endoreplication cycle was apparent in the antheridial non-generative cells suggesting a possible presence of a DNA remodeling mechanism in Chara. The 1C-value found in the cells of the filaments at a mature stage of spermiogenesis has an absolute content of 4.47 pg. The obtained data on DNA amount was combined and analyzed with those available on Chara spp. in the literature. An n = 14 chromosome number was confirmed for this population. Spontaneous anomalies such as laggard chromosomes, formation of micronuclei or amitotic nuclear divisions by gradually pulling apart the nucleus into two parts, were observed in some cells of the antheridial filaments.