ESTIMATION OF THE MITOTIC CYCLE IN LARVAL BRAIN CELLS OF THE HOUSE FLY

1970 ◽  
Vol 12 (4) ◽  
pp. 779-784 ◽  
Author(s):  
K. Y. Jan ◽  
J. W. Boyes
Keyword(s):  
Cell Cycle ◽  
Mitotic Cycle ◽  
House Fly ◽  
Total Cell ◽  
Brain Cells ◽  
Theoretical Expectation ◽  
Larval Brain ◽  
Third Instar Larvae

An attempt to estimate the mitotic cycle in brain cells of the house fly was made by injecting thymidine-methyl-H3 into third instar larvae. The G2 period plus prophase was about 1.5 hours for some of the XX and XY cells. The graph of the percentages of metaphases labelled deviated considerably from the theoretical expectation, preventing a valid estimation of the duration of G1, S, mitosis and total cell cycle. The probable causes of such deviation have been discussed.

DURATION OF MITOTIC CYCLE IN BRAIN CELLS OF THE MOSQUITO, AEDES DORSALIS

1969 ◽  
Vol 11 (3) ◽  
pp. 673-676 ◽  
Author(s):  
Asit B. Mukherjee ◽  
Don M. Rees
Keyword(s):  
Cell Cycle ◽  
High Resolution ◽  
Mitotic Cycle ◽  
Brain Cells ◽  
Duration Of Mitosis ◽  
High Resolution Autoradiography

Duration of the mitotic cycle and its various phases in the dividing brain cells of Aedes dorsalis larvae has been determined by high-resolution autoradiography. The length of the cell cycle is 10 hours. The duration of G1 is about 1 hour and 15 minutes, DNA synthetic period (S) is approximately 7 hours, G2 is 1 hour and the duration of mitosis (M) is about 45 minutes.

scholarly journals Cell cycle analysis of brain cells as a growth index in larval cod at different feeding conditions and temperatures

2007 ◽  
Vol 71 (3) ◽  
pp. 485-497 ◽  
Author(s):  
Rafael González-Quirós ◽  
Iyziar Munuera ◽  
Arild Folkvord
Keyword(s):  
Cell Cycle ◽  
Growth Index ◽  
Cell Cycle Analysis ◽  
Brain Cells

scholarly journals Differences in cell cycle characteristics among patients with acute nonlymphocytic leukemia

Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1647-1653 ◽  
Author(s):  
A Raza ◽  
Y Maheshwari ◽  
HD Preisler
Keyword(s):  
Cell Cycle ◽  
Tritiated Thymidine ◽  
S Phase ◽  
Total Cell ◽  
Acute Nonlymphocytic Leukemia ◽  
Cell Cycle Time ◽  
Myeloid Leukemias ◽  
History Of

The proliferative characteristics of myeloid leukemias were defined in vivo after intravenous infusions of bromodeoxyuridine (BrdU) in 40 patients. The percentage of S-phase cells obtained from the biopsies (mean, 20%) were significantly higher (P = .00003) than those determined from the bone marrow (BM) aspirates (mean, 9%). The post- BrdU infusion BM aspirates from 40 patients were incubated with tritiated thymidine in vitro. These double-labeled slides were utilized to determine the duration of S-phase (Ts) in myeloblasts and their total cell cycle time (Tc). The Ts varied from four to 49 hours (mean, 19 hours; median, 17 hours). Similarly, there were wide variations in Tc of individual patients ranging from 16 to 292 hours (mean, 93 hours; median, 76 hours). There was no relationship between Tc and the percentage of S-phase cells, but there was a good correlation between Tc and Ts (r = .8). Patients with relapsed acute nonlymphocytic leukemia (ANLL) appeared to have a longer Ts and Tc than those studied at initial diagnosis. A subgroup of patients at either extreme of Tc were identified who demonstrated clinically documented resistance in response to multiple courses of chemotherapy. We conclude that Ts and Tc provide additional biologic information that may be valuable in understanding the variations observed in the natural history of ANLL.

scholarly journals In vivo determination of cell cycle kinetics of non-Hodgkin's lymphomas using iododeoxyuridine and bromodeoxyuridine.

1992 ◽  
Vol 40 (5) ◽  
pp. 723-728 ◽  
Author(s):  
G Yanik ◽  
N Yousuf ◽  
M A Miller ◽  
S H Swerdlow ◽  
B Lampkin ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lymphoma ◽  
Large Cell ◽  
S Phase ◽  
Total Cell ◽  
Growth Fraction ◽  
Cycle Times ◽  
Large Cell Lymphoma ◽  
Hodgkin's Lymphomas

Using sequential infusions of two S-phase-specific drugs, iododeoxyuridine and bromodeoxyuridine, we have developed an in vivo method for determining the labeling index (LI), the S-phase duration (Ts), and total cell cycle times (Tc) of non-Hodgkin's lymphomas. In nine non-Hodgkin's lymphomas studied, the LI ranged from 1.5% in a follicular small cleaved-cell lymphoma to 29.6% in a diffuse large-cell lymphoma. The Ts ranged from 16 hr in a large-cell lymphoma (immunoblastic type) to 117 hr in a follicular small cleaved-cell lymphoma. The Tc varied from 69 hr in a large-cell lymphoma (immunoblastic type) to over 1000 hr in all low-grade lymphomas studied. Immunohistochemical methods using anti-BrdU antibodies were used to detect cell incorporation of the two S-phase-specific drugs. In this manner, cell cycle times could be calculated while the architecture of the tumor specimen was preserved. Difficulties in using this methodology, specifically in the calculation of the growth fraction and total cell cycle times, are pointed out. This in vivo method does, however, allow for Ts calculations independent of growth fraction considerations. Correlations of cell cycle data with various biological and clinical factors await further patient follow-up.

scholarly journals Role of Drosophila Rap/Fzr (DCdh1) in Retinal Axon Targeting and its Interactions with Loco and Liprin-alpha

2020 ◽  
Author(s):  
Marta Grońska-Pęski ◽  
Tadmiri R. Venkatesh
Keyword(s):  
Cell Cycle ◽  
Ubiquitin Ligase ◽  
Axon Growth ◽  
Scaffolding Protein ◽  
List Type ◽  
Axon Targeting ◽  
The Third ◽  
Retinal Axon ◽  
Third Instar Larvae

AbstractThe development of the wild type Drosophila compound eye involves stereotypical targeting of photoreceptor axons to the specific layers of the optic ganglion, medulla and lamina, in the third instar larvae. To test the hypothesis that ubiquitin ligases play an important role during retinal axon targeting we have examined the patterns of axon targeting in the developing eye of the retina aberrant in pattern (rap/fzr) mutants. Rap/Fzr is a homolog of mammalian Cdh1, an activator of anaphase promoting complex (APC), a multi-subunit E3 ubiquitin ligase, regulating the cell cycle progression. Previous work has shown that Rap/Fzr is required during eye development for proper cell cycle regulation, glia differentiation and pattern formation. It was also necessary for proper neuromuscular junction development and circadian rhythms. Our results show that Rap/Fzr is required for proper retinal axon targeting in the developing eye. Using ro-tau-lacZ, we show that the R2-R5 axons fail to stop in the lamina and mis-target to the medulla levels. Also, mosaic analyses experiments using FLP-FRT and GAL4-UAS techniques show that Rap/Fzr functions in a cell autonomous manner. To test for possible role of other signalling molecules and interactions with Rap/Fzr, we have examined rap/fzr axon projection phenotypes in double mutant combinations with the RGS protein, locomotion defective (loco) mutants and a scaffolding protein, Liprin-α. Our studies suggest that Rap/Fzr is required for proper axon targeting during Drosophila visual system development, and the phenotype is enhanced in double mutants with either loco or Liprin-α. These results are consistent with other mammalian studies reporting a role of Cdh1 in axon growth and targeting and provides further insights into neuronal functions of the ubiquitin ligase APC/CCdh1.HighlightsLoss of rap/fzr in the third instar Drosophila eye disc leads to photoreceptor axon overgrowthOverexpression of rap/fzr leads to photoreceptor axon leads to axon shortening and clumpingLoss of LocoP452 leads to photoreceptor overgrowthDouble mutants of rap and loco or rap and Liprin-α show axon enhancement of the axon targeting defects in the Drosophila third instar larvae eye imaginal discs.

scholarly journals Developmental compartments in the larval trachea of Drosophila

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Prashanth R Rao ◽  
Li Lin ◽  
Hai Huang ◽  
Arjun Guha ◽  
Sougata Roy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Notch Signaling ◽  
Clonal Analysis ◽  
Border Cells ◽  
Tracheal System ◽  
Dorsal Branch ◽  
Dividing Cells ◽  
Organizational Feature ◽  
Third Instar Larvae

The Drosophila tracheal system is a branched tubular network that forms in the embryo by a post-mitotic program of morphogenesis. In third instar larvae (L3), cells constituting the second tracheal metamere (Tr2) reenter the cell cycle. Clonal analysis of L3 Tr2 revealed that dividing cells in the dorsal trunk, dorsal branch and transverse connective branches respect lineage restriction boundaries near branch junctions. These boundaries corresponded to domains of gene expression, for example where cells expressing Spalt, Delta and Serrate in the dorsal trunk meet vein–expressing cells in the dorsal branch or transverse connective. Notch signaling was activated to one side of these borders and was required for the identity, specializations and segregation of border cells. These findings suggest that Tr2 is comprised of developmental compartments and that developmental compartments are an organizational feature relevant to branched tubular networks.

Cell-cycle-dependent effects of sodium-n-butyrate in Physarum polycephalum

1982 ◽  
Vol 58 (1) ◽  
pp. 303-311
Author(s):  
P. Loidl ◽  
P. Grobner ◽  
A. Csordas ◽  
B. Puschendorf
Keyword(s):  
Cell Cycle ◽  
Fatty Acids ◽  
Protein Synthesis ◽  
Physarum Polycephalum ◽  
Mitotic Cycle ◽  
Short Chain Fatty Acids ◽  
Time Interval ◽  
Retarding Effect ◽  
Rna And Protein Synthesis ◽  
Cycle Dependent

Sodium-n-butyrate affects the length of the mitotic cycle of Physarum polycephalum. Application during S- or early G2-period results in a delay of the subsequent mitosis, whereas application later in the cycle has no delaying effect. Interestingly, the second mitotic cycle after application is considerably shortened when butyrate has been administered during S- or early G2-period of the preceding cycle. In comparison, other homologous short-chain fatty acids were tested; the retarding effect on mitosis increases with the number of carbon atoms, although only butyrate can shorten the second mitotic cycle. It is shown that butyrate causes an immediate depression of synthesis of DNA, RNA and protein. After a certain time-interval the plasmodium overcomes the butyrate block. DNA synthesis is fully recovered and the inhibition of RNA and protein synthesis is even overcompensated until the next mitosis, as reflected by elevated levels of RNA and protein.

The Effect of Enucleation on Flagellar Regeneration in the Protozoon Peranema Trichophorum

1969 ◽  
Vol 4 (1) ◽  
pp. 171-178
Author(s):  
S. L. TAMM
Keyword(s):  
Cell Cycle ◽  
Mitotic Cycle ◽  
Living Cells ◽  
Regeneration Capacity ◽  
Flagellar Regeneration ◽  
Single Living Cells ◽  
Single Living

A rotocompressor was used to enucleate the flagellate protozoon Peranema trichophorum at known stages in the mitotic cycle. This new enucleation technique, combined with recently devised methods for amputating the flagellum and recording its regeneration in single living cells, permitted the investigation of the role of the nucleus in flagellar regeneration at different cell ages. The flagellar regeneration capacity of an enucleate Peranema depended on the stage in the cell cycle when the nucleus was removed. Post-division enucleate cells regenerated about half the length reached by sham-operated controls, and at slower rates, while predivision enucleate cells regenerated flagella equally as well as the controls. Therefore, the nucleus is making an immediate contribution to flagellar regeneration early in the cell cycle, but not late in the cell cycle.

scholarly journals A Meiosis-Specific Cyclin Regulated by Splicing Is Required for Proper Progression through Meiosis

2005 ◽  
Vol 25 (15) ◽  
pp. 6330-6337 ◽  
Author(s):  
Jordi Malapeira ◽  
Alberto Moldón ◽  
Elena Hidalgo ◽  
Gerald R. Smith ◽  
Paul Nurse ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Chromosome Segregation ◽  
Mitotic Cycle ◽  
Mitotic Cell ◽  
S Phase ◽  
Mitotic Cell Cycle ◽  
Meiotic Cell ◽  
Cyclin Dependent Kinases ◽  
Negative Factor

ABSTRACT The meiotic cell cycle is modified from the mitotic cell cycle by having a premeiotic S phase which leads to high levels of recombination, a reductional pattern of chromosome segregation at the first division, and a second division with no intervening DNA synthesis. Cyclin-dependent kinases are essential for progression through the meiotic cell cycle, as for the mitotic cycle. Here we show that a fission yeast cyclin, Rem1, is present only during meiosis. Cells lacking Rem1 have impaired meiotic recombination, and Rem1 is required for premeiotic DNA synthesis when Cig2 is not present. rem1 expression is regulated at the level of both transcription and splicing, with Mei4 as a positive and Cig2 a negative factor of rem1 splicing. This regulation ensures the timely appearance of the different cyclins during meiosis, which is required for the proper progression through the meiotic cell cycle. We propose that the meiosis-specific B-type cyclin Rem1 has a central role in bringing about progression through meiosis.

scholarly journals Centrioles in the cell cycle. I. Epithelial cells.

1982 ◽  
Vol 93 (3) ◽  
pp. 938-949 ◽  
Author(s):  
I A Vorobjev ◽  
Chentsov YuS
Keyword(s):  
Cell Cycle ◽  
Mitotic Cycle ◽  
Spindle Pole ◽  
Pig Kidney ◽  
Spindle Poles ◽  
Mother And Daughter ◽  
Mother Centriole ◽  
Spindle Microtubules ◽  
S Period ◽  
Number Of Cells

A study was made of the structure of the centrosome in the cell cycle in a nonsynchronous culture of pig kidney embryo (PE) cells. In the spindle pole of the metaphase cell there are two mutually perpendicular centrioles (mother and daughter) which differ in their ultrastructure. An electron-dense halo, which surrounds only the mother centriole and is the site where spindle microtubules converge, disappears at the end of telophase. In metaphase and anaphase, the mother centriole is situated perpendicular to the spindle axis. At the beginning of the G1 period, pericentriolar satellites are formed on the mother centriole with microtubules attached to them; the two centrioles diverge. The structures of the two centrioles differ throughout interphase; the mother centriole has appendages, the daughter does not. Replication of the centrioles occurs approximately in the middle of the S period. The structure of the procentrioles differs sharply from that of the mature centriole. Elongation of procentrioles is completed in prometaphase, and their structure undergoes a number of successive changes. In the G2 period, pericentriolar satellites disappear and some time later a fibrillar halo is formed on both mother centrioles, i.e., spindle poles begin to form. In the cells that have left the mitotic cycle (G0 period), replication of centrioles does not take place; in many cells, a cilium is formed on the mother centriole. In a small number of cells a cilium is formed in the S and G2 periods, but unlike the cilium in the G0 period it does not reach the surface of the cell. In all cases, it locates on the centriole with appendages. At the beginning of the G1 period, during the G2 period, and in nonciliated cells in the G0 period, one of the centrioles is situated perpendicular to the substrate. On the whole, it takes a mature centriole a cycle and a half to form in PE cells.

Sign in / Sign up

Export Citation Format

Share Document