The karyotype of Ukrainian population of river buffalo (River Buffalo)

Abstract

In recent years, the genetic structure of the buffaloes has been particularly widespread due to the use of molecular methods, in particular microsatellite DNA regions. In Ukraine, such studies were conducted on the basis of the Ukrainian Laboratory of Quality and Safety of Agricultural Product. Equally important is the chromosomal analysis – the study of the morphology, number and structure of the chromosomes, which is not sufficiently investigated in the buffaloes.

The purpose of our work is to study the chromosomal set of buffaloes of the river Ukrainian population.

The material for the study was the peripheral blood of adult river buffaloes, which are contained in the monastery household "Holy Protection of Thoetokos" – LLC "Golosiyevo". Preparation of the culture of lymphocytes and preparation of preparations of chromosomes was carried out on the basis of the Genetics Laboratory of the Institute of Animal Breeding and Genetics nd. a. M.V.Zubets NAAS. For the preparation of chromosomal preparations, 0.5 ml of whole heparinized peripheral blood was cultured in 5 ml of RPMI 1640 medium with the addition of koncanavalin (Sigma, USA) as mitogen, L-glutamine, gentamicin antibiotic and fetal serum. The culture was incubated at 37°C for 72 hours. A 0.2 ml solution of colchicine (10 μg / ml) was inoculated into each culture tube and incubated for an additional 2 hours. The culture was maintained in a hypotonic solution of KCl (0.075 M) and fixed in a mixture of methanol and acetic acid (3:1). The cell suspension was applied to the occasional wet substrate glass. The preparations were stained with 2% Giemsa dye, analyzed by microscope for an increase of 1000 times and photographed.

In work 10 females of river buffalo, which are breeding in Ukraine are investigated. As a result of the analysis of the obtained drugs, it was found that the chromosomal set of investigated buffalo contains 50 chromosomes (2n = 50). The preparations clearly distinguish all pairs of autosomes at the metaphase of the mitosis from the first to the twenty-fourth and the sex chromosomes X and Y. The five pairs of the largest autosomes, from the first to the fifth, have a sub-metacentric structural structure. The remaining 19 pairs of chromosomes are acrocentric. Sexual X-chromosome is the largest acrocentric that has a morphological feature: something like a membrane, which makes it easy to distinguish this chromosome among others. Y chromosome is a small acrocentric structure.

As a result of the analysis of the chromosomal sets of investigated buffaloes, aberrations of both numeric and structural type were identified. Of the total number of (351) studied chromosomal drugs, 30.8% of the cells were aberrant. The frequency of genomic aberrations was: aneuploid cells – 5.55 ± 1.47%, polyploidy – 0.22 ± 0.14%. The spectrum of structural aberrations is represented by fragments and a premature divergence of the chromosome centromer with a frequency of 1.55 ± 0.62 and 1.66 ± 0.64, respectively.

Unlike bovine cattle, the systematic program of cytogenetic buffalo screening is absent, there are only isolated reports of single chromosomal abnormalities found in individual animal groups.

According to researchers, the most common anomalies of the buffalo (mostly river type) chromosomes are abnormalities of the sex chromosomes, which include X-trisomy, X-monosomy, XXY-syndrome and mosaicism XX / XY (fremartinism). Unlike bovine animals, reports of structural aberrations of autosomes, such as translocations, are rarely found in river buffaloes.

The study of buffalo cytogenetic polymorphism is of interest to cover one of the most complex issues of the systematization of mammals and has practical implications for improving the protection, reproduction and rational use of these rare animals. A cytogenetic monitoring of Bubalus bubalis can be an important tool in breeding programs and will improve the use of genetic resources of domestic animals.