CYTOLOGICAL STUDIES ON ORGANIZATION OF DNA IN GIANT TROPHOBLAST NUCLEI OF MOUSE AND RAT
CYTOLOGICAL STUDIES ON ORGANIZATION OF DNA IN GIANT TROPHOBLAST NUCLEI OF MOUSE AND RAT
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DOI：
10.1007/bf00331800
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发表时间：
1974-01-01
期刊：
影响因子：
1.6
通讯作者：
SHERMAN, MI
中科院分区：
文献类型：
--
作者：
BARLOW, PW;SHERMAN, MI
小鼠和大鼠的巨大滋养层细胞核，已知含有数百甚至数千倍的DNA，已经通过许多细胞学技术进行了研究。这些细胞核呈现两种形态学状态：“网状”，其中大量大小均匀的染色质丝混杂在整个细胞核中，通常从核仁附近的异染色质团块辐射，和“均匀”，其中染色质更均匀地分散，单个丝更难以区分。还观察到中间形态。在这两种情况下，类似于多线染色体的结构可辨别。- Giemsa BSG技术揭示的着丝粒异染色质已被定量分析巨大与二倍体滋养细胞核。虽然巨细胞核的染色中心数中位数略高于二倍体细胞核，但范围相似。在这两种情况下，染色中心数通常小于染色体对的二倍体数，表明着丝粒之间的吸引力不仅同源，而且异源，染色体。通过扫描显微光密度测定，我们观察到巨细胞的染色中心面积与核总面积之比是恒定的。该比值可能反映了染色中心体积与总核体积的比值，与卫星DNA与总DNA的比值非常一致。
Giant trophoblast nuclei of the mouse and the rat, known to contain hundreds, or even thousands, of times the haploid amount of DNA, have been studied by a number of cytological techniques. These nuclei appear in two morphological states:“reticulate,” in which large numbers of chromatin threads of uniform size intermingle throughout the nucleus, often radiating from clumps of heterochromatin adjacent to the nucleoli, and “homogeneous,” in which the chromatin is more evenly dispersed and individual threads are more difficult to distinguish. Intermediate morphologies are also observed. In neither case were structures resembling polytene chromosomes discernible. — Centromeric heterohromatin as revealed by the Giemsa BSG technique has been quantitatively analyzed in giant versus diploid trophoblast nuclei. Although the median number of chromocenters is slightly greater in giant than in diploid nuclei, the range is similar. In both cases, the chromocenter number is usually less than the diploid number of chromosome pairs, indicating the attraction between centromeres not only of homologous, but also of heterologous, chromosomes. By scanning microdensitometry, we have observed a constant ratio of chromocenter area: total nuclear area in giant cells. This ratio, which likely reflects the ratio of chromocenter volume: total nuclear volume, is in good agreement with that of satellite DNA: total DNA.