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Cell Biology International (1998) 22, 227–236 (Printed in Great Britain)
ANTHERIDIAL CHROMATIN CONDENSATION FACTOR FROM MALE SEX ORGANS OFCHARA TOMENTOSA
ANDRZEJ KAŹMIERCZAK and JANUSZ MASZEWSKI
Department of Cytophysiology, University of Łódź, 90-231, Łódź, ul. Pilarskiego 14, Poland


Abstract

Incubation of roots (Melandrium noctiflorum) in crude extracts obtained from maturing male sex organs ofChara tomentosaresults in supercondensation of mitotic chromosomes. The observed changes, including a number of ‘secondary effects’, confirm precisely with all those kinds of alterations which are typical of M-phase cells in antheridial filaments during their progression from the proliferative period of development towards terminal differentiation into sperm cells. Biological assays performed with proteinaceous extracts of maturing antheridia indicate that the activity is confined merely to a fraction containing low molecular (4.5kDa) peptides, termed as ACCF (antheridial chromatin condensation factor). Microchemical tests showed the acidic character of ACCF and its apparent ability to form cross-links with histones and DNA-histone complexes, mediated presumably by disulfide bridges. The characteristic punctate distribution of vesicles within the cytoplasm suggests the internalization of rhodamine-isothiocyanate labelled ACCF (ACCF-TRITC) by endocytosis, implying possible sequestering and nuclear translocation upon release from the endosomal/lysosomal compartment of the cell.


Key words: chromosome supercondensation, spermatogenesis, Chara tomentosa, Melandrium noctiflorum, endocytosis.


Received 21 March 1997; accepted 11 March 1998

doi:10.1006/cbir.1998.0242


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)