Distribution of Nucleic Acid Sequences in Lampbrush Chromosomes

Abstract

Although for the most part this chapter will be concerned with sequences that are transcribed in amphibian oocytes, studies in this field have progressed in such a way that transcribed sequences cannot be considered in isolation from sequences that are not transcribed. Neither can lampbrush chromosomes be considered in isolation, for work on other chromosomes has frequently supplied evidence that is essential for the proper appraisal of the primary topic of this chapter. Much of the information at present available has come from the use of in situ hybridization, the singularly valuable autoradiographic technique devised by Gall and Pardue (1969) and by H. A. John et al. (1969). Mention has been made of one outcome of this technique in the section of Chap. 3 dealing with nucleolus organizers, but here I will discuss wider aspects.