DNA Content in Nuclei of Cyclops kolensis and Cyclops insignis(Crustacea, Copepoda)

摘要

Chromatin diminution (CD) in two Cyclopoida species, Cyclops kolensis and Cyclops insignis, was studied by static digital Feulgen cytophotometry. DNA content (pg/cell) was evaluated with standard dependences constructed by amounts of DNA in the bloodcells of five organisms with known DNA contents of 1.25-14.7 pg. It was found that the C. kolensis diploid genome had about 40 pg DNA before CD and 1.8-2.0 pg DNA after CD. These values are similar both for Moscow and Baikal population of C. kolensis andexceed previous estimates by six to ten times (Grishanin, 2008). Our data confirm that CD reaches 94-96% of DNA content in C. kolensis. In mitotic cells of C. insignis DNA content was about 7.5 pg in both early and late embryos; CD was not revealed forthis species. The data obtained show that the DNA content in the C. kolensis genome before CD is highest among the examined Cyclopoides.