CHROMATIN DIMINUTION IN CYCLOPS KOLENSIS (COPEPODA, CRUSTACEA) IS A UNIQUE EXAMPLE OF GENETIC-ENGINEERING IN NATURE

Data on chromatin diminution (CD) in Cyclops kolensis and Cyclops stre nuus strenuus obtained by means of light microscopy, cytofotometry, an d molecular biology methods are presented. C. kolensis somatic cell li nes were found to lose nearly 94% of DNA through CD at the fourth clea vage division, and the value of haploid genome changes from 2.3 to 0.1 4 pg. CD in C. strenuus strenuus has two steps and occurs at the fifth and sixth cleavages. About 75% of DNA is eliminated from presomatic c ells as a result. The chromosome numbers in the diploid nuclei of C. k olensis and C. strenuus strenuus cells did not change during CD, remai ning at 22 and 24, respectively. Highly polyploid cells were detected in adult individuals of both Cyclops species. Rearrangement of DNA seq uences in the genome of C. kolensis in the course of CD was revealed b y means of the arbitrary primed polymerase chain reaction method.