Comparative analysis of karyotypes of Вovidae family from the evolutionary aspect

Abstract

Aim. The aim of the study was to analyze chromosome sets of specific species of agricultural animals of Bovidae family using the techniques of differentiated G- and Ag-banding of chromosomes and to demonstrate the role of their variability in the evolution. Methods. The culture of lymphocytes and chromosome preparations were pre- pared by the method of Moorhead et al (1960). The preparations of metaphase chromosomes were analyzed by the G-banding methods of Barch M J et al (1997) and by Ag-banding method of Zhu JJ et al (2019). The chromosomal aberrations were classified according to the recommendations of the International System for Chromosome No- menclature of Domestic Bovids (2001). The dendrogram of phylogenetic relations between mammalian species was built using “STATISTICA 6.1”. Results. The comparative study of the chromosomal sets of cattle Bos taurus, domestic sheep Ovis aries and river buffalo Bubalus bubalis bubalis was conducted using G- and Ag-banding methods. The homology of the structural organization of chromosomes and the evolutionary changes in karyotypes of Bovidae family were analyzed, highlighting their sex chromosomes and the chromosomes with specific local- ized groups of gene linkage. A considerable homology of chromosome sites was found in the representatives of the investigated species by the G-banding profiles. To study the phylogenetic interrelations, the index of the number of active nucleolus organizer regions (NOR) in the chromosomes during the metaphase stage was used. Conclu- sions. The comparison of the morphology of chromosomes of agricultural animals of Bovidae family, Bos taurus, Ovis aries, and Bubalus bubalis bubalis confirms the association between the homology of some chromosomal sites and the formation of metacentric chromosomes due to the linkage of acrocentric ones. The species-specific morphological differences in sex chromosomes of the investigated animals were found in terms of the length and presence of pericentric inversions. The phylogenetic relations between the species of Bovidae family demonstrate that the value of distances, determined based on the variability of the number of active NOR, reflects the degree of their phylogenetic similarity.