Ribosomal gene amplification in the oocytes of Creophilus maxillosus (Staphylinidae, Coleoptera-Polyphaga) - An insect with telotrophic ovaries

We have shown that the extrachromosomal DNA body present in the oocyte nucleus of Creophilus maxillosus contains amplified copies of ribosomal DNA and that multiple nucleoli associated with extrachromosomal DNA body contain ribosomal RNA. In addition, we assessed the level of rDNA amplification in Creophilus oocytes. The amount of DNA in single extra DNA body corresponds to 86% of total nuclear DNA content or 617% of chromosomal DNA content. In Creophilus, there are two phases of transcriptional activity of extrachromosomal rDNA, first in oogonia, and second in growing oocytes, separated by a short period of transcriptional quiescence in the ovary of newly hatched imago. We have described the organization and activity of extra DNA body in RNA synthesis and production of multiple nucleoli in previtellogenic stages of oocyte growth in imaginal ovariole of Creophilus.