Some Observations Co Ncerning
نویسنده
چکیده
One of the more perplexing aspects of mitosis has been the na ture of the mechan ism whereby the chromosomes are moved into their metaphase configuration. Early theories of chromosome movemen t which involved the spindle or chromosomal fibers later gave way to theories proposing alternate mechanisms, as spindle fibers came to be regarded as artifacts of fixation. In recent years, however, evidence for the actual existence of spindle fibers has accumulated, notably Inou6's studies showing the birefringence of the spindle in living mater ia l (Inou6, 1953). Recently improved elect ron microscope techniques have now revealed great numbers of fine fi laments hav ing a tubu la r appearance and a d iameter of approximately 15 to 20 m/z in osmium tetroxide-fixed mater ia l (Roth et al., 1960; Ro th and Daniels, 1962; Harris, 1962; and others). The present paper describes the fine s tructure of the mitotic appara tus at p rometaphase of the first cleavage division, showing the early a t t a c h m e n t of these filaments to the chromosomes and their insertion into the centrosphere region at the poles.
منابع مشابه
Some Observations Co Ncerning
One of the more perplexing aspects of mitosis has been the na ture of the mechan ism whereby the chromosomes are moved into their metaphase configuration. Early theories of chromosome movemen t which involved the spindle or chromosomal fibers later gave way to theories proposing alternate mechanisms, as spindle fibers came to be regarded as artifacts of fixation. In recent years, however, evide...
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