Ultrastructural and autoradiographic studies of non-generative cells in the antheridium of Chara vulgaris. II. Capitular cells.
In young antheridia, the structure of capitular cells is typical of meristematic cells. The cytoplasm is characterized by poorly developed ER system, numerous free ribosomes, active Golgi apparatus and plastids at the stage of proplastids. In the period of mitotic divisions, i.e. during formation of the initial cells of antheridial filaments, the nuclei of capitular cells have a changing structure. When capitular cells stop budding leading to the formation of successive antheridial filaments. DNA content in the nucleus is at 2C-4C level. The nucleolus with nucleolonema-like structure becomes gradually smaller in the course of the development of the anteheridium. During spermiogenesis capitular cells are vacuolated, cytoplasm contains numerous polysomes, mitochondria assume condensed structure, the incorporation of 3N-uridine and of labelled aminoacids increases. It has been suggested that capitular cells collaborate with other antheridial cells in the regulation of the course of spermiogenesis.
Kwiatkowska
M
M
Laboratory of Cytophysiology, University of Lódź, Poland.
Maszewski
J
J
D001345:Autoradiography; D002455:Cell Division; D004247:DNA / Q000032:analysis; D008297:Male; D059828:Plant Cells; D010944:Plants / Q000378:metabolism / Q000648:ultrastructure; D014176:Protein Biosynthesis; D013091:Spermatogenesis; D014158:Transcription, Genetic; D014316:Tritium; D014364:Tryptophan / Q000378:metabolism; D014529:Uridine / Q000378:metabolism
D014316:Tritium; D014364:Tryptophan; D004247:DNA; D014529:Uridine