Abstract
The major chromomeres of pachytene chromosomes 6 and 11 in the oocytes of Acheta (Orthoptera) are regions of amplification for ribosomal RNA cistrons (28 S and 18 S). During late prophase the amplified DNA copies are released from the chromomeres, which decrease in size as the amount of DNA decreases. The number of nucleotide pairs released from the major chromomere of chromosome 11 is about 1.38 x 10(9).