scholarly journals Emerging mechanisms regulating mitotic synchrony during animal embryogenesis

2017 ◽  
Vol 59 (7) ◽  
pp. 565-579 ◽  
Author(s):  
Yosuke Ogura ◽  
Yasunori Sasakura
Keyword(s):  
Mitotic Synchrony

scholarly journals Two alleles of a developmentally regulated alpha-tubulin locus in Physarum polycephalum replicate on different schedules.

1993 ◽  
Vol 13 (1) ◽  
pp. 449-461 ◽  
Author(s):  
D B Cunningham ◽  
W F Dove
Keyword(s):  
Replication Timing ◽  
S Phase ◽  
Temporal Organization ◽  
Developmentally Regulated ◽  
Alpha Tubulin ◽  
Homologous Chromosomes ◽  
Allele Specific ◽  
Rna Blots ◽  
Temporal Windows ◽  
Mitotic Synchrony

The replication timing of a pair of natural alleles was compared at two alpha-tubulin loci of the Physarum plasmodium. Taking advantage of the naturally synchronous cell cycle of nuclei within the syncytial plasmodium, we analyzed the replication schedule of specific DNA fragments to a resolution of 10-min intervals within a 3-h S phase. At this level of resolution, differences in replication timing between polymorphic alleles at the same locus can be detected in a heterozygote. Specifically, the 3' region of the altA1 allele completes replication at between 20 and 40 min of S phase. The same region of the altA2 allele completes replication at between 40 and 80 min of S phase. In contrast, both alleles at the altB locus replicate concurrently within the first 10 to 15 min of S phase. Previous studies showed that both altA and altB are expressed in the plasmodium, their message levels peaking at mitosis, just minutes before the onset of S phase. However, altB message is detected at substantially higher levels than altA message on Northern (RNA) blots. The temporal windows over which the altA alleles each replicate are very broad in comparison with the levels of mitotic synchrony and altB replication synchrony in a single plasmodium. The allele-specific replication schedule of the altA locus demonstrates that the temporal organization of replicons is not strictly conserved between homologous chromosomes.

scholarly journals Colcemid Effects on Mitotic Synchrony and Synchronized Cells

1976 ◽  
Vol 1 (2) ◽  
pp. 187-195
Author(s):  
Hiroshi Ohara ◽  
Toyozo Terasima
Keyword(s):  
Synchronized Cells ◽  
Mitotic Synchrony

Two alleles of a developmentally regulated alpha-tubulin locus in Physarum polycephalum replicate on different schedules

1993 ◽  
Vol 13 (1) ◽  
pp. 449-461
Author(s):  
D B Cunningham ◽  
W F Dove
Keyword(s):  
Replication Timing ◽  
S Phase ◽  
Temporal Organization ◽  
Developmentally Regulated ◽  
Alpha Tubulin ◽  
Homologous Chromosomes ◽  
Allele Specific ◽  
Rna Blots ◽  
Temporal Windows ◽  
Mitotic Synchrony

The replication timing of a pair of natural alleles was compared at two alpha-tubulin loci of the Physarum plasmodium. Taking advantage of the naturally synchronous cell cycle of nuclei within the syncytial plasmodium, we analyzed the replication schedule of specific DNA fragments to a resolution of 10-min intervals within a 3-h S phase. At this level of resolution, differences in replication timing between polymorphic alleles at the same locus can be detected in a heterozygote. Specifically, the 3' region of the altA1 allele completes replication at between 20 and 40 min of S phase. The same region of the altA2 allele completes replication at between 40 and 80 min of S phase. In contrast, both alleles at the altB locus replicate concurrently within the first 10 to 15 min of S phase. Previous studies showed that both altA and altB are expressed in the plasmodium, their message levels peaking at mitosis, just minutes before the onset of S phase. However, altB message is detected at substantially higher levels than altA message on Northern (RNA) blots. The temporal windows over which the altA alleles each replicate are very broad in comparison with the levels of mitotic synchrony and altB replication synchrony in a single plasmodium. The allele-specific replication schedule of the altA locus demonstrates that the temporal organization of replicons is not strictly conserved between homologous chromosomes.

Induction of Mitotic Synchrony by Intermittent Hyperthermia in Ehrlich Carcinoma in vivo

Nature ◽  
1973 ◽  
Vol 244 (5414) ◽  
pp. 299-300 ◽  
Author(s):  
MICHAEL D. SAPOZINK ◽  
ELEANOR E. DESCHNER ◽  
ERIC W. HAHN
Keyword(s):  
Ehrlich Carcinoma ◽  
Mitotic Synchrony

l(3)malignant brain tumor and Three Novel Genes Are Required for Drosophila Germ-Cell Formation

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 1889-1900 ◽  
Author(s):  
Christopher B Yohn ◽  
Leslie Pusateri ◽  
Vitor Barbosa ◽  
Ruth Lehmann
Keyword(s):  
Brain Tumor ◽  
Germ Cell ◽  
Germ Plasm ◽  
Nuclear Division ◽  
Cell Formation ◽  
Nuclear Migration ◽  
Early Embryo ◽  
Malignant Brain Tumor ◽  
Mitotic Synchrony ◽  
Germ Cell Formation

Abstract To identify genes involved in the process of germ-cell formation in Drosophila, a maternal-effect screen using the FLP/FRT-ovoD method was performed on chromosome 3R. In addition to expected mutations in the germ-cell determinant oskar and in other genes known to be involved in the process, several novel mutations caused defects in germ-cell formation. Mutations in any of three genes [l(3)malignant brain tumor, shackleton, and out of sync] affect the synchronous mitotic divisions and nuclear migration of the early embryo. The defects in nuclear migration or mitotic synchrony result in a reduction in germ-cell formation. Mutations in another gene identified in this screen, bebra, do not cause mitotic defects, but appear to act upstream of the localization of oskar. Analysis of our mutants demonstrates that two unique and independent processes must occur to form germ cells—germ-plasm formation and nuclear division/migration.

Ionic coupling and mitotic synchrony of siblings in a Drosophila cell line

1989 ◽  
Vol 184 (2) ◽  
pp. 509-517 ◽  
Author(s):  
David C. Spray ◽  
Lucy Cherbas ◽  
Peter Cherbas ◽  
E.A. Morales ◽  
Grant M. Carrow
Keyword(s):  
Cell Line ◽  
Drosophila Cell ◽  
Mitotic Synchrony ◽  
Drosophila Cell Line ◽  
Ionic Coupling

scholarly journals Mad2, Bub3, and Mps1 regulate chromosome segregation and mitotic synchrony in Giardia intestinalis, a binucleate protist lacking an anaphase-promoting complex

2014 ◽  
Vol 25 (18) ◽  
pp. 2774-2787 ◽  
Author(s):  
Juan-Jesus Vicente ◽  
W. Zacheus Cande
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Mitotic Checkpoint ◽  
Giardia Intestinalis ◽  
Anaphase Promoting Complex ◽  
Critical Importance ◽  
Minimal Set ◽  
Left Hand ◽  
Mitotic Checkpoint Complex ◽  
Mitotic Synchrony

The binucleate pathogen Giardia intestinalis is a highly divergent eukaryote with a semiopen mitosis, lacking an anaphase-promoting complex/cyclosome (APC/C) and many of the mitotic checkpoint complex (MCC) proteins. However, Giardia has some MCC components (Bub3, Mad2, and Mps1) and proteins from the cohesin system (Smc1 and Smc3). Mad2 localizes to the cytoplasm, but Bub3 and Mps1 are either located on chromosomes or in the cytoplasm, depending on the cell cycle stage. Depletion of Bub3, Mad2, or Mps1 resulted in a lowered mitotic index, errors in chromosome segregation (including lagging chromosomes), and abnormalities in spindle morphology. During interphase, MCC knockdown cells have an abnormal number of nuclei, either one nucleus usually on the left-hand side of the cell or two nuclei with one mislocalized. These results suggest that the minimal set of MCC proteins in Giardia play a major role in regulating many aspects of mitosis, including chromosome segregation, coordination of mitosis between the two nuclei, and subsequent nuclear positioning. The critical importance of MCC proteins in an organism that lacks their canonical target, the APC/C, suggests a broader role for these proteins and hints at new pathways to be discovered.

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