Location and behaviour of constitutive heterochromatin during meiotic prophase in Beta vulgaris L.
1980
Jong, J.H. de | Oud, J.L. (Amsterdam Univ. (Netherlands). Inst. of Genetics)
Male meiotic prophase of diploid sugarbeet (Beta vulgaris L.) has been studied with emphasis on location and behaviour of the constitutive heterochromatin during the early prophase stages. The succession of the stages is determined by using anther length, size of the pollen mother cell nuclei and degree of development of the tapetal cells as criteria. Besides, the maturity gradient through each pollen sac and the high synchrony of the meiotic stages within each flowerbud prove to be valuable tools for establishing the stage succession. Preparations of squashed anthers were stained according to a special carmine-Giemsa technique and the C-banding technique. Thus, information has been obtained on the formation of the synizetic knot and the morphological changes of the chromatin taking place during diplotene, with special reference to the diffuse stage. The observations are discussed and compared with data obtained by electron microscopical and biochemical investigations. Some mechanisms underlying these observations are presented
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