Asymmetric Cell Divisions in the Early Embryo of the Leech
... Molecular phylogenies have converged on grouping bilaterally symmetric animals into three major clades, a significantly reduced Deuterostomia, and, from the former Protostomia, two new super-phyla called Ecdysozoa and Lophotrochozoa (Aguinaldo et al. 1997; Ruiz-Trillo et al. 1999). Combining this co ...
... Molecular phylogenies have converged on grouping bilaterally symmetric animals into three major clades, a significantly reduced Deuterostomia, and, from the former Protostomia, two new super-phyla called Ecdysozoa and Lophotrochozoa (Aguinaldo et al. 1997; Ruiz-Trillo et al. 1999). Combining this co ...
Caryoneme alternative to chromosome and a new caryological
... nowadays in the sense of a substance containing, consisting of, or showing the staining and other reactions of deoxypentose nucleic acid. In the present state of biochemical and genetical knowledge, it seems doubtful whether it continues to serve as a useful purpose.” As a matter of fact, Barber & C ...
... nowadays in the sense of a substance containing, consisting of, or showing the staining and other reactions of deoxypentose nucleic acid. In the present state of biochemical and genetical knowledge, it seems doubtful whether it continues to serve as a useful purpose.” As a matter of fact, Barber & C ...
Cell cycle parameters of hESC are highly similar to - HAL
... segregate into epiblast and primitive endoderm. Based on mitotic index examination, A.J Copp observed that while the number of cells composing the mural trophectoderm increases considerably in late blastocyst embryos, mural trophectodermal cells divide slower than polar ones [16-18]. This observati ...
... segregate into epiblast and primitive endoderm. Based on mitotic index examination, A.J Copp observed that while the number of cells composing the mural trophectoderm increases considerably in late blastocyst embryos, mural trophectodermal cells divide slower than polar ones [16-18]. This observati ...
Cell cycle regulation during early mouse embryogenesis.
... segregate into epiblast and primitive endoderm. Based on mitotic index examination, A.J Copp observed that while the number of cells composing the mural trophectoderm increases considerably in late blastocyst embryos, mural trophectodermal cells divide slower than polar ones [16-18]. This observati ...
... segregate into epiblast and primitive endoderm. Based on mitotic index examination, A.J Copp observed that while the number of cells composing the mural trophectoderm increases considerably in late blastocyst embryos, mural trophectodermal cells divide slower than polar ones [16-18]. This observati ...
Reverse Engineering Models of Cell Cycle Regulation
... To reverse engineer the network we need a few clues about the master regulator R (also known as MPF, M-phase promoting factor). By 1989 it was known that MPF is a dimer of cdc2 and cyclin B.20,21 The level of cdc2 in cells is constant, but its cyclin partner comes and goes. MPF activity is abruptly ...
... To reverse engineer the network we need a few clues about the master regulator R (also known as MPF, M-phase promoting factor). By 1989 it was known that MPF is a dimer of cdc2 and cyclin B.20,21 The level of cdc2 in cells is constant, but its cyclin partner comes and goes. MPF activity is abruptly ...
TMBP200, a Microtubule Bundling Polypeptide Isolated from
... The full-length cDNA was obtained using RT-PCR and RACE-PCR methods. The cDNA for TMBP200 encodes a polypeptide of 2,029 amino acids with an estimated relative molecular mass of 223 kDa (Fig. 8). Searches of current databases revealed that TMBP200 belongs to a family of weakly ...
... The full-length cDNA was obtained using RT-PCR and RACE-PCR methods. The cDNA for TMBP200 encodes a polypeptide of 2,029 amino acids with an estimated relative molecular mass of 223 kDa (Fig. 8). Searches of current databases revealed that TMBP200 belongs to a family of weakly ...
Activating the DNA damage checkpoint in a developmental context
... in M are very different physiological responses. It has been proposed that differential responses to checkpoint activation arise from inherent differences in the way mitosis is regulated [1]. The budding yeast cell cycle lacks a defined G2 period and executes certain mitotic events, such as the dupl ...
... in M are very different physiological responses. It has been proposed that differential responses to checkpoint activation arise from inherent differences in the way mitosis is regulated [1]. The budding yeast cell cycle lacks a defined G2 period and executes certain mitotic events, such as the dupl ...
Mitosis in the Mouse: A Study of Living and
... from the large nucleoli in his cells were, in fact, associated with the chromocentres sticking to the surface of the nucleoli. Our films show that in early prophase the nucleus often revolves. The rotation usually occurs in greatly expanded cells and seems to be associated with the spindle, since th ...
... from the large nucleoli in his cells were, in fact, associated with the chromocentres sticking to the surface of the nucleoli. Our films show that in early prophase the nucleus often revolves. The rotation usually occurs in greatly expanded cells and seems to be associated with the spindle, since th ...
Compaction and segregation of sister chromatids via active loop
... One hypothesis of how condensins can generate compaction without crosslinking of topologically distinct chromosomes is that they bind to two nearby points and then slide to generate a progressively larger loop (Nasmyth, 2001). This ’loop extrusion’ process creates an array of consecutive loops in in ...
... One hypothesis of how condensins can generate compaction without crosslinking of topologically distinct chromosomes is that they bind to two nearby points and then slide to generate a progressively larger loop (Nasmyth, 2001). This ’loop extrusion’ process creates an array of consecutive loops in in ...
The enhancement of histone H4 and H2A serine 1 phosphorylation
... Received: 15 December 2003 / Revised: 8 March 2004 / Accepted: 19 March 2004 / Published online: 7 May 2004 # Springer-Verlag 2004 ...
... Received: 15 December 2003 / Revised: 8 March 2004 / Accepted: 19 March 2004 / Published online: 7 May 2004 # Springer-Verlag 2004 ...
Cell-cycle regulation
... 3. Regulators of the cell cycle 3.1. CDKs and cyclins The C. elegans genome encodes multiple members of the cyclin-dependent kinase (CDK) family. At least two CDKs, CDK-1 and CDK-4, are essential for cell-cycle progression (Boxem et al., 1999; Boxem and van den Heuvel, 2001; Park and Krause, 1999). ...
... 3. Regulators of the cell cycle 3.1. CDKs and cyclins The C. elegans genome encodes multiple members of the cyclin-dependent kinase (CDK) family. At least two CDKs, CDK-1 and CDK-4, are essential for cell-cycle progression (Boxem et al., 1999; Boxem and van den Heuvel, 2001; Park and Krause, 1999). ...
Gene Section AURKB (aurora kinase B) Atlas of Genetics and Cytogenetics
... 2A (PP2A) (Sugiyama et al., 2002) regulate Aurora B kinase activation while MKlp2 controls Aurora B localization in anaphase (Gruneberg et al., 2004). Regarding mitotic chromosome condensation, Aurora B directly phosphorylates histone H3, not only at S10 but also at S28. The level of S28 phosphoryla ...
... 2A (PP2A) (Sugiyama et al., 2002) regulate Aurora B kinase activation while MKlp2 controls Aurora B localization in anaphase (Gruneberg et al., 2004). Regarding mitotic chromosome condensation, Aurora B directly phosphorylates histone H3, not only at S10 but also at S28. The level of S28 phosphoryla ...
LIFEPAC® 10th Grade Science Unit 8 Worktext - HomeSchool
... using gametes has a different genetic composition than either parent. Each individual obtains its genetic information from both parents, but the combination of traits the new individual has is different from that of either parent. Recall that there are two divisions in meiosis. The chromosomes of a ...
... using gametes has a different genetic composition than either parent. Each individual obtains its genetic information from both parents, but the combination of traits the new individual has is different from that of either parent. Recall that there are two divisions in meiosis. The chromosomes of a ...
as a PDF
... fusion proteins (n = 33 cells, 4.1min average duration at 3.85sec intervals) revealed discrete sites of apparent microtubule initiation at the cell cortex (Fig. 1A,B). Microtubules that depolymerized to visible completion rarely showed recovery (48 of 50 events with >2min of imaging after depolymeri ...
... fusion proteins (n = 33 cells, 4.1min average duration at 3.85sec intervals) revealed discrete sites of apparent microtubule initiation at the cell cortex (Fig. 1A,B). Microtubules that depolymerized to visible completion rarely showed recovery (48 of 50 events with >2min of imaging after depolymeri ...
Plant-specific mitotic targeting of RanGAP
... For correspondence (fax 614 292 5379; e-mail [email protected]). ...
... For correspondence (fax 614 292 5379; e-mail [email protected]). ...
Arabidopsis Kinetochore Fiber-Associated MAP65-4
... MAP65-2 induces stable MT bundles in vitro and is localized with almost all of the MT arrays present in plant cells (Li et al., 2009). The biochemical properties of the remaining MAP65s are not known, and most studies have focused on their subcellular localization using antibodies and green fluoresc ...
... MAP65-2 induces stable MT bundles in vitro and is localized with almost all of the MT arrays present in plant cells (Li et al., 2009). The biochemical properties of the remaining MAP65s are not known, and most studies have focused on their subcellular localization using antibodies and green fluoresc ...
1 Cell polarity and asymmetric cell division: the C. elegans early
... become clearly noticeable by DIC (Figure 1A). While the ruffling of the cortex culminates in one pronounced invagination in the middle of the embryo (pseudocleavage), the female pronucleus starts migrating towards the posterior pole to meet the sperm pronucleus. The two pronuclei meet in the posteri ...
... become clearly noticeable by DIC (Figure 1A). While the ruffling of the cortex culminates in one pronounced invagination in the middle of the embryo (pseudocleavage), the female pronucleus starts migrating towards the posterior pole to meet the sperm pronucleus. The two pronuclei meet in the posteri ...
Asymmetric cell division and axis formation in the embryo
... During these early cleavage divisions, the three principal axes of the body plan are established. First, the anterior-posterior (AP) axis is set up in the one-cell stage, with the sperm-derived centrosome breaking the symmetry of the oocyte and initiating a sequence of events relying on maternally-c ...
... During these early cleavage divisions, the three principal axes of the body plan are established. First, the anterior-posterior (AP) axis is set up in the one-cell stage, with the sperm-derived centrosome breaking the symmetry of the oocyte and initiating a sequence of events relying on maternally-c ...
10–2 Cell Division
... 2 Stages of cell division in eukaryotes: 1.Mitosis 2.Cytokinesis Mitosis is the division of the nucleus. Cytokinesis is the division of the cytoplasm. ...
... 2 Stages of cell division in eukaryotes: 1.Mitosis 2.Cytokinesis Mitosis is the division of the nucleus. Cytokinesis is the division of the cytoplasm. ...
Colorado Agriscience Curriculum
... turning on its axis causing the rising and setting of the sun. You know, just like the cycles seen in nature, our cells replicate in the same way, in phases or cycles. We have already learned about the cell and the importance of the organelles within cells. Has anyone ever wondered about the life cy ...
... turning on its axis causing the rising and setting of the sun. You know, just like the cycles seen in nature, our cells replicate in the same way, in phases or cycles. We have already learned about the cell and the importance of the organelles within cells. Has anyone ever wondered about the life cy ...
γ-Tubulin Is Essential for Microtubule Organization and
... The process of microtubule nucleation in plant cells is still a major question in plant cell biology. g-Tubulin is known as one of the key molecular players for microtubule nucleation in animal and fungal cells. Here, we provide genetic evidence that in Arabidopsis thaliana, g-tubulin is required fo ...
... The process of microtubule nucleation in plant cells is still a major question in plant cell biology. g-Tubulin is known as one of the key molecular players for microtubule nucleation in animal and fungal cells. Here, we provide genetic evidence that in Arabidopsis thaliana, g-tubulin is required fo ...
Spindle checkpoint
During the process of cell division, the spindle checkpoint prevents separation of the duplicated chromosomes until each chromosome is properly attached to the spindle apparatus. In order to preserve the cell's identity and proper function, it is necessary to maintain the appropriate number of chromosomes after each cell division. An error in generating daughter cells with fewer or greater number of chromosomes than expected (a situation termed aneuploidy), may lead in best case to cell death, or alternatively it may generate catastrophic phenotypic results. Examples include: In cancer cells, aneuploidy is a frequent event, indicating that these cells present a defect in the machinery involved in chromosome segregation, as well as in the mechanism ensuring that segregation is correctly performed. In humans, Down syndrome appears in children carrying in their cells one extra copy of chromosome 21, as a result of a defect in chromosome segregation during meiosis in one of the progenitors. This defect will generate a gamete (spermatozoide or oocyte) with an extra chromosome 21. After fecundation, this gamete will generate an embryo with three copies of chromosome 21.The mechanisms verifying that all the requirements to pass to the next phase in the cell cycle have been fulfilled are called checkpoints. All along the cell cycle, there are different checkpoints. The checkpoint ensuring that chromosome segregation is correct is termed spindle assembly checkpoint (SAC), spindle checkpoint or mitotic checkpoint. During mitosis or meiosis, the spindle checkpoint prevents anaphase onset until all chromosomes are properly attached to the spindle. To achieve proper segregation, the two kinetochores on the sister chromatids must be attached to opposite spindle poles (bipolar orientation). Only this pattern of attachment will ensure that each daughter cell receives one copy of the chromosome.