ABSTRACT
Asymmetric transfer of a solitonic kink between telomeric loops shared by template-replica chromatids is conceptualized in terms of homotopic dynamics. Downscaled to B-Z DNA these ideas lead to interesting possibilities regarding duplication and/or selective activation of genes located at or near DNA "hybrid" chiralities.
Subject(s)
Chromatids/genetics , Models, Genetic , Telomere/genetics , Anaphase/genetics , Animals , DNA/genetics , Mammals/geneticsABSTRACT
The paper discusses a system of hinged leverages functioning as (vectorial) pantographic motors (PMs). Mediated by ratchets, PMs are suited for ferrying mammalian chromatids to mitotic antipoles. Several self-rectifying modes allow PMs to accurately partition genomes with minimal risk of engendering aneuploidy.
Subject(s)
Chromatids/metabolism , Chromatids/physiology , Aneuploidy , Animals , Biological Transport, Active , Humans , Ions , Kinetochores/metabolism , Mitosis , Models, Theoretical , Molecular Motor ProteinsABSTRACT
This paper discusses a mechanism for converting heterochromatin into the more relaxed state of euchromatin. Actuation of such state conversion stems from disassembly of internal vesicles that are incapable of surviving when trapped within the inner chamber of mammalian nuclei.
Subject(s)
Euchromatin/physiology , Gene Expression Regulation/physiology , Mammals/genetics , Animals , Cell Nucleus/ultrastructure , Euchromatin/genetics , Heterochromatin/genetics , Heterochromatin/physiology , Interphase , Models, Genetic , Nuclear Envelope/physiology , Organelles/physiologyABSTRACT
On the basis of numerical and kinetic data, the paper argues against the tenet that BCR-Abl is sufficient for transforming into Chronic Myelogenous leukemia a human hemopoietic stem cell, regardless of degree of pluripotency.
Subject(s)
Cell Transformation, Neoplastic/genetics , Fusion Proteins, bcr-abl/physiology , Hematopoietic Stem Cells/pathology , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/etiology , Neoplastic Stem Cells/pathology , Adult , Fusion Proteins, bcr-abl/genetics , Granulocytes/pathology , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Models, Biological , Reference ValuesABSTRACT
The paper discusses how the environment of regional lymph nodes optimizes growth of metastatic cells shed by non-autonomous tumoral primaries.
Subject(s)
Lymph Nodes/pathology , Neoplasm Seeding , HumansABSTRACT
In general terms the paper discusses the relevance of mitotically quiescent, malignant cells for increasing resistance to chemotherapy. Detailed are some routes to Go for malignancies either dependent or autonomous for their mitotic potential.
Subject(s)
Drug Resistance, Neoplasm , Neoplasms/pathology , Resting Phase, Cell Cycle , HumansABSTRACT
The paper discusses malignant transformation of myeloid precursors that had atypical renewal in vivo. Their in vitro transformation rate disproportionates clinical incidences. Besides composition differences of transforming agents, this is due to quali-quantitative deficiencies of multitask growth factors added to empirical cultures. In combination these anomalies perturb the web of differentiation path, whose robustness minimizes clonal transformation in vivo.
Subject(s)
Bone Marrow Cells/pathology , Cell Transformation, Neoplastic , Cell Division , Cell Lineage , HumansABSTRACT
Using order parameters from field theory, the paper rationalizes the statistics of myeloid and erythroid leukemias more satisfactorily than the random mutation hypothesis. Adapted to B- and plasma cell lineages, the same arguments conceptualize the statistics of related malignancies congruently to clinical findings.
Subject(s)
Leukemia, Erythroblastic, Acute/epidemiology , Leukemia, Myeloid/epidemiology , Acute Disease , Cell Lineage , Chronic Disease , Humans , Incidence , Leukemia, Erythroblastic, Acute/pathology , Leukemia, Myeloid/pathologyABSTRACT
Disentanglement of centromeric braids is refined in 3 dimensions. Besides expanding the combinatronics of chromatid polarization in comparison to 2-D formats, the present study discusses certain chromosomal anomalies such as the statistics of isochromatids and variants thereof in cancer cells.
Subject(s)
Centromere/physiology , Centromere/ultrastructure , Chromatids/physiology , Chromatids/ultrastructure , Chromosome Aberrations , Animals , Centromere/genetics , Chromatids/genetics , Humans , Mammals , Models, Genetic , Models, Structural , Neoplasms/geneticsABSTRACT
The paper discusses a mechanism for segmental insertions (ins) between two chromatids. In human cancers, such rearrangements are significantly less frequent than reciprocal translocations (rt). Regarding the clinical incidence of ins versus rt, the proposed dynamics is more satisfactory than the random mutation hypothesis.
Subject(s)
Chromosome Aberrations , Neoplasms/genetics , Translocation, Genetic , HumansABSTRACT
This paper discusses a mechanism whereby a sister replica unit separates from its template via a flip-rotation rather than by eversion. Such an unusual process engenders a permanent antidromic sequence, as well as two (evanescent) kinks only on the stack of the replicated chromatid.
Subject(s)
Chromatids/genetics , Base Sequence , DNAABSTRACT
The paper proposes a mechanism for regulating nucleo-cytoplasmic exchanges of macromolecules via NPC in vertebrates. Bending of NE toward the transport vector significantly contributes to the dynamics.
Subject(s)
Cell Nucleus/metabolism , Cytoplasm/metabolism , Nuclear Envelope/metabolism , Animals , Biological Transport , VertebratesABSTRACT
We investigate how chromatin entanglements may subvert the topology of DNA segments (and of genes therein) whenever sister chromatids separate by eversion. Such subversions offer interesting ideas on how identical genes may be differently or identically expressed after segregation of sister chromatids.
Subject(s)
Chromatids , Chromatin/metabolismABSTRACT
The paper discusses how a DNA strand contributes pivots that distributively interconnect the jaws of two or more C units of a chromatid stack. Rather than being static, the location of these pivots may be shifted according to alternative modes without compromising the chromatid's physical integrity.
Subject(s)
Chromatids/genetics , Chromatids/ultrastructure , Animals , Humans , Mammals , Models, Genetic , Models, StructuralABSTRACT
The paper discusses a mechanism apt to convert the topology of a straight chromatid into one that could lead to the formation of a O-ring. It is predicted that such conversions might occur only in exceptional circumstances, due to a combination of poorly correlated events.
Subject(s)
Chromatids/ultrastructure , Models, Genetic , Humans , Sister Chromatid ExchangeABSTRACT
After considering few alternative possibilities, it is concluded that eversion is the most efficient mechanism for disengagement of replica chromatids from their templates.
Subject(s)
Models, Genetic , Sister Chromatid Exchange , Humans , Templates, GeneticABSTRACT
The paper studies mammalian chromatids conformed as donut-like rings. Albeit enacting many topologic and dynamic aspects of straight chromatids (e.g. replication, eversion, antipodal segregation at anaphase, etc.), rings differ in certain properties regarding in particular disposal of soliton-like, kinked frustrations of their chirality during recurrent sister chromatid exchanges (SCEs).
Subject(s)
Chromatids , Models, Genetic , Animals , Chromatids/chemistry , Chromatids/physiology , Humans , Models, Molecular , Sister Chromatid ExchangeABSTRACT
The paper discusses a mechanism for semiconservative duplication of a pair of centrioles from a single parent. The mechanism accounts for the (transient or permanent) quasi-orthogonality of mammalian centrioles.
Subject(s)
Centrioles/physiology , Centrioles/ultrastructure , Animals , Biomechanical Phenomena , Elasticity , Humans , Microtubules/physiology , Mitosis/physiology , Models, BiologicalABSTRACT
Rescaling of chromatid C units into similar but smaller epsilon (epsilon) subunits is discussed. When subverted, these subunits are responsible for repositioning genes in different states of transcriptional accessibility via an analogy in miniature of more massive sister chromatid exchanges.
