ISSN:
0886-1544
Keywords:
metaphase
;
anaphase
;
spindle
;
oogenesis
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The transition from metaphase to anaphase was examined in primary oocytes of the Mediterranean mealmoth, Ephestia kuehniella. Isolated spindles were analysed using phase-contrast microscopy and antitubulin immunofluorescence. Metaphase I bivalents in female Lepidoptera contain material derived from the synaptonemal complexes, the elimination chromatin, which is located between the homologs. Upon the onset of anaphase I, the homologs detach from the elimination chromatin. The present observations revealed that prior to the start of anaphase A, the homologs move centripetally, i.e., toward the central spindle axis, while the elimination chromatin remains stationary. This type of movement is not directly comparable with conventional chromosome movements such as prometaphase congression, anaphase A, and anaphase B, since it occurs at right angles to the preferential orientation of the spindle MTs. A MT-based mechanism may nevertheless account for the centripetal shift of homologs in meiosis I of the moth: bundling of kinetochore MTs of different chromosomes could transfer the chromosomes toward the spindle axis. Since the homologs move along the poleward surfaces of the plate of elimination chromatin, a MT-independent force producer could exist as well at the interface between the chromosomes and the plate of elimination chromatin. © 1993 Wiley-Liss, Inc.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970240307
