Sr. Bisgrove et al., IMMUNOLOCALIZATION OF CENTRIN DURING FERTILIZATION AND THE FIRST CELL-CYCLE IN FUCUS-DISTICHUS AND PELVETIA-COMPRESSA (FUCALES, PHAEOPHYCEAE), Journal of phycology, 33(5), 1997, pp. 823-829
Antibodies that recognize the centrosome-associated protein centrin we
re used to characterize centrosomal origin and positioning during fert
ilization and the first cell cycle in Fucus distichus subsp. evanescen
s (C. Agardh) Powell and Pelvetia compressa (J. Agardh) Be Tent. Centr
in was identified in sperm, eggs, and zygotes on protein blots, indica
ting the protein is present in both gametes. Using immunofluorescence
microscopy, centrin was found in discrete foci in sperm. In contrast,
eggs lack centrosomes and centrin was not detectable by immunofluoresc
ence, indicating that centrin was probably dispersed in the cytoplasm.
Two foci of centrin were present on the nuclear envelope of zygotes,
but microtubules remained dispersed over the zygotic nucleus. Centrin
foci separated over the nuclear envelope as the first cell cycle progr
essed. Microtubules became concentrated at the centrin foci to form ce
ntrosomes that gave rise to the spindle poles at mitosis.