Insects, Год журнала: 2024, Номер 15(8), С. 593 - 593
Опубликована: Авг. 4, 2024
Currently, clusters of 45S and 5S ribosomal DNA (rDNA) have been studied in about 1000 100 species the class Insecta, respectively. Although number insect with known rDNA (also referred to as nucleolus-organizing regions, or NORs) constitutes less than 0.1 percent described members this enormous group, certain conclusions can already be drawn. Since haploid karyotypes single predominate both basal derived groups, character state is apparently ancestral for Insecta general. Nevertheless, number, chromosomal location, other characteristics sites substantially vary across different species, sometimes even within same species. There are several main factors molecular mechanisms that either maintain these parameters alter them on short-term and/or long-term scale. Chromosome structure (i.e., monocentric vs. holokinetic chromosomes), excessive numbers rRNA gene copies per cluster, interactions transposable elements, pseudogenization, meiotic recombination perhaps most important among them.
Язык: Английский