Identification and Structure of Lampbrush Sex Bivalents Prior to and afterthe Reproductive Period of the European Domestic Goose Anser anser

摘要

Lampbrush chromosomes (LBCs) present in bird oocytes are a new model in cytogeneticswith particular significance for bird chromosome analysis. The fact that female birds areheterogametic makes it possible to observe both sex chromosomes in the form ofdecondensed structures typical of lampbrush chromosomes. A change in transcriptionactivity associated with physiological processes in geese prior to and after the reproductiveseason is reflected in chromosome morphology. Lampbrush chromosomes obtained after thereproductive period have reduced side loops, sites of intensive transcriptional activity.However, noticeable characteristics in the chromosomes include inactive chromomeres.Chiasms, PBs, large side loops (ML) and telomeric loops (T, TLL, and GLL) are structuresthat undergo degradation latest after the termination of reproduction, and as a result,constitute the basis of identification of individual bivalents in different periods of the cell'stranscriptional activity.