Cine Micrographic Studies on Mitotic Spiralization Cycle

Holm, Gerhard; Bajer, A.

doi:10.1111/j.1601-5223.1966.tb02027.x

Cited by 9 publications

(4 citation statements)

References 13 publications

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“…The presence of chromonemal organization within chromatids of metaphase chromosomes is WKi 1978; IG6-KEMENES and ZACHAU 1978; VOGEL-quite unambiguously documented both with light microscope (see, e.g., MANTON 1950;HOLM and BAJER 1966;OHNUKI 1968;HAAPALA and NOKKALA 1982;NOKKALA and NOKKALA 1985) and electron microscope (RUZICKA 1973; HAAPALA and NOKKALA 1982). Recently, it has been established (NOKKALA and NOKKALA 1985) that the chromonema within mitotic and second meiotic metaphase chromatids represents a so-called primary chromonema equaling or being half of the length of pachytene chromosome.…”

Section: Discussionmentioning

confidence: 90%

“…Ample evidence is available for the fact that the last step in chromosome condensation is the coiling of chromonema resulting in the mature metaphase chromatid (see, e.g., MANTON 1950;HOLM and BAJER 1966;OHNUKI 1968;HAAPALA and NOKKALA 1982;NOKKALA and NOKKALA 1985). Recently, it has been established that within mitotic and second meiotic metaphase chromosomes the chromonema is a so-called primary chromonema equaling or being half of the pachytene chromosome length .…”

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confidence: 99%

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Coiled internal structure of chromonema within chromosomes suggesting hierarchical coil model for chromosome structure

Nokkala

2008

Hereditas

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Internal structure of chromonema within chromosomes at the second meiotic division in Mecostethus grossus was studied by staining the axial filament of chromonema with silver nitrate. It was found that axial filament is the coiling product of axial fiber, allowing the conclusion that the internal structure of chromonema is coiled. On the grounds of the present observation combined with other available observations on structural details of chromosomes, a new model for chromosome structure is presented. According to the model, three organizational levels above the 30 nm fiber can be identified. The first level is formed by the loop‐interloop organization of the 30 nm fiber, where interloop regions form a seemingly continuous axial fiber housing the axial DNA. The second level of organization, a chromonema, is achieved by the coiling of the 30 nm axial fiber. The coiled axial fiber forms axial filament or the axial system of chromonema. The third level of organization is the mature metaphase chromatid, which is formed by the coiling of chromonema, i. e., the model is based on the principle of hierarchical coilings of axial DNA. On the basis of the model, detailed quantitative account for package of DNA in Drosophila, human, and Lilium chromosomes is given. Since the packing of coils in both coiling cycles evidently shows species specific variation, it is obvious that there is a species specific packing ratio of axial DNA by which the total package of DNA within metaphase chromatid is achieved. Furthermore, it is suggested that in meiotic cells, only part of axial DNA stretches function as zygDNA and participate in the formation of lateral elements of meiotic prophase chromosomes.

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Section: Discussionmentioning

confidence: 90%

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confidence: 99%

Coiled internal structure of chromonema within chromosomes suggesting hierarchical coil model for chromosome structure

Nokkala

2008

Hereditas

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“…Baranetzky was the first to find spiral bands in the chromosomes of Tradescantia (Baranetzky, ). The chromosome spiral structure was observed by light microscopy both in mitotic chromosomes fixed in situ and after different treatments that promoted chromosome decondensation (Manton, ; Holm and Bajer, ; Ohnuki, ; Haapala and Nokkala, ). It was not possible to precisely determine the size of these fibers using light microscopy, but it was obvious that they were larger than chromonemata, which cannot be seen under a non‐fluorescent microscope due to the limitations of microscope resolution.…”

Section: –250 Nm Fibermentioning

confidence: 99%

Chromatin fibers: from classical descriptions to modern interpretation

Kuznetsova

Sheval

2016

Cell Biology International

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The first description of intrachromosomal fibers was made by Baranetzky in 1880. Since that time, a plethora of fibrillar substructures have been described inside the mitotic chromosomes, and published data indicate that chromosomes may be formed as a result of the hierarchical folding of chromatin fibers. In this review, we examine the evolution and the current state of research on the morphological organization of mitotic chromosomes.

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“…In compact metaphase chromosomes, helical gyn are not visible light microscopically, chromatids usually having a homogeneous appearance. The condensation of chromosomes towards metaphase has been suggested to be accomplished as a process of gyre elimination (SWANSON 1943;HOLM and BAJER 1966;BAK et al 1981;HARRISON et al 1981;JOHNSON et al 198 I): the number of gyri decreases towards metaphase, while the width of gyri is increasing with the apparent decrease of the length of the chromonema. In the present approach to studying the consecutive and simultaneous events of compaction, human lymphocyte chromosomes were screened for the number of macrocoil gyri and Giemsa dark bands at a variety of chromosome length preceding metaphase.…”

Section: Chromatid Compactionmentioning

confidence: 99%

Chromatid macrocoiling and chromosome compaction

Haapala

2008

Hereditas

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Haapala, O. 1984. Chromatid macrocoiling and chromosome compaction. —Hereditas 100: 17–27. Lund, Sweden. ISSN 0018–0661. Received March 17, 1983 The process of chromosome compaction was studied by the observation of the number of macrocoil gyri within a variety of chromosome lengths towards metaphase. The number of gyri was found to remain almost unchanged from the onset of macrocoiling until compact metaphase codiration, suggesting that chromatid contraction by coiling is not accompanied by gyre elimination. The specific helical dimensions of chromosome 1 macrocoils were measured and the lengths of helical chromonemata were calculated. The lengths varied between 18.1 and 23.9 mUm and, accordingly, the chromonemal lengths of 192–249 mUm for the autosome set were derived. The coiling pattern of the individual chromatid arms indicated that chromatid arms do not spiralize, in respect to the coil direction (left‐ or right‐handed helix) they generate, randomly within a chromosome. Present results, along with theoretical considerations, make possible a better interpretation of the relationship of chromatid substructures emerging during mitotic condensation of chromosomes.

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Cine Micrographic Studies on Mitotic Spiralization Cycle

Cited by 9 publications

References 13 publications

Coiled internal structure of chromonema within chromosomes suggesting hierarchical coil model for chromosome structure

Coiled internal structure of chromonema within chromosomes suggesting hierarchical coil model for chromosome structure

Chromatin fibers: from classical descriptions to modern interpretation

Chromatid macrocoiling and chromosome compaction

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