Synthesis of nucleic acids associated with a DNA-containing body in oocytes of Acheta

Abstract

A large DNA containing body is found in gonial and in oocyte nuclei of the house cricket, Acheta domesticus. The DNA body is present in addition to chromosomal DNA and accounts for approx. 25% of the DNA in early prophase nuclei. Synthesis of this extra DNA continues into early prophase of meiosis long after DNA synthesis is completed by the chromosomes. While it is being formed, the DNA body is intimately associated with one or more chromosome pairs. Large quantities of nucleolar material accumulate at the periphery of the body during the diplotene stage of development. The DNA body of diplotene cells is composed of an inner core of Feulgen-positive material surrounded by a mass of RNA. As the cells proceed through the diplotene stage, it is proposed that DNA from the central core of the body acts as a template for synthesis of nucleolar RNA and in so doing is incorporated into the nucleolar mass.