Indicates that this ability is retained by the protein. Conservation of the “hinge region” consensus in MENT Known for their ability to undergo dramatic conformational transitions. The amino acid sequence of MENT reveals a close structural relationship with serpins, a large family of proteins exceptionally compact polynucleosomes, which maintain a level of higher order folding above that imposed by linker Cryoelectron microscopy of chicken granulocyte chromatin, which is highly enriched with MENT, In vertebrate blood cells, these changes can be traced to the accumulation of a developmentally regulated Terminal cell differentiation is correlated with the extensive sequestering of previously active genes into compact transcriptionally Finally, when we assay simultaneously for nuclear-DNA organization and cell membrane organization a progressive uncoupling between nuclear and cell morphometry is apparent if B16-F10 (versus B16-F1). Scanning cytometry of the Feulgen stained sorted subpopulation reveals that the cells possess a unique nuclear morphometry characterized by a 2C-3C DNA content and a large nuclear area (disperse chromatin). This subpopulation when assayed in vivo produced significantly more pulmonary metastases than its parent cell line. Utilizing a sterile cell sorting technique, a subpopulation of B16-F10 with increased fluorescamine uptake representing 30% of the total "intact cell" population was isolated by means of a fluorescence activated cell sorter and replated in vitro. Fluorescamine uptake and poststaining viability is shown to be dependent upon the dye/cell ratio at which staining occurs. (membranes) provides the identification of a homogeneous subpopulation of cells with enhanced metastatic potential based on differential fluorescamine uptake. Furthermore, double staining of B16-F10 and B16-F1 with ethidium bromide (chromatin) and fluorescamine. An illustrated work was published on Orchid pollination and evolution (Dodson 1961).Ĭhromatin structure, in terms of higher order nuclear-DNA condensation (scanning cytometry) and in terms of acridine orange primary binding sites (flow cytometry), is analyzed and shown to be significantly different between high (B16-F10) and low (B16-F1) metastatic variants of B16 melanoma. In broad features of the karyotype, the family as a whole represents a normal grouping, as karyotype alterations, though playing a role in evolution, are equally effective at an intra and interspecific level. In general, genera cannot be categorised on the basis of their karyotypes. In Vanda, polyploidy and aneuploidy occurring at intra and interspecific level as well as cryptic structural alterations have been considered to be the factors which have contributed to the wide geographical distribution and adaptation of the genus. The position of the species Hexisea reflexa, newly recorded here from India, has been assigned under Sarcanthineae. The cytological affinity of Stauropsis with Vanda has been shown. In the subtribe Sarcanthineae, the affinity of Aerides with Sarcachilus has been revealed and presence of supernumerary constriction indicates the extent to which structural changes of chromosomes are operating in evolution.
Dressler (1961) described the northern epiphytes of Mexico and also recorded the severe frost-damage in them excepting Epidendrum conopseum R. chrysanthum where such cytotypes are correlated with distinct environmental conditions. Intraspecific chromosome races are common and a clear case has been demonstrated in D.
In the subtribe Dendrobeae, the genus Dendrobium is quite homogeneous in which polyploidy and aneuploidy along with chromosome changes have played an important role in evolution. On the basis of the chromosome behaviour and karyotype analysis it has been concluded that in the subtribe Coelogyneae, the genus Pholidota is allied to Coelogyne and those two represent homogeneous assemblages. There are 17 new reports from Eastern Himalayas and the Khasia hills. The present paper deals with a detailed chromosome study of 35 species including cytotypes of the tribe Kerosphaereae of Orchidaceae.
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