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IDENTIFICATION OF BIOLOGICAL MATERIALS OF CATTLE USING GENETIC
MARKERS
Nosirova M.B.
Republican center for forensic expertise Ferghana Department
Uzbekistan, Ferghana, B.Margiloniy street, 121
Email: maftun.nosirova1990@gmail.com
https://doi.org/10.5281/zenodo.15469508
Genetic material (DNA) related to cattle is extracted from biological samples provided
for research. These samples may include meat samples, skin samples, hair, horns, and bone
samples. Specific requirements are set for pieces of animals' muscle or other tissues. The
methods of DNA extraction from different biological materials of cattle vary by method. Аfter
extraction the concentration of extracted DNA was quantified by using the Qubit 4.0
fluorometer (Thermo Fisher Scientific, USA) and the Qubit dsDNA HS Assay Kit (Thermo
Fisher Scientific, USA), following the manufacturer's recommended protocols. For the PCR
amplification process of the extracted cattle DNA samples, the "COrDIS Cattle" kit was used.
The PCR amplification process was performed using the COrDIS Cattle kit protocol. The
following amplification requirements are recommended as standard parameters. It is
important to control the heating rate during the temperature rise from 59°C to 72°C to be
0.3°C per second. Due to the high complexity of the amplification involving 15 primer pairs,
this heating rate is crucial for the optimal efficiency of the reaction.
For obtaining a complete STR profile of the sample, 0.2 nanograms of extracted DNA is
sufficient. The optimal amount is 1 nanogram. PCR was performed on the samples using
ProFlex PCR System (Applied Biosystems, USA) and the PCR products were analyzed using the
SeqStudio 8 Flex genetic analyzer (Hitachi, Japan).
After the analysis is completed, it is necessary to evaluate the results of analyzing the
positive control sample. The genotype of the obtained positive control sample was compared
with the genotype specified in the manual. Since the genotype of the positive control sample
completely matched the expected sample, the genotyping of the analyzed samples continued.
Each marker locus in the electropherogram may correspond to one or two PCR
products, corresponding to homozygous and heterozygous states. The difference in allele
length is usually 2 base pairs, reflecting differences in the number of dinucleotide repeats. To
correctly determine the genotype, it is necessary to take into account the nature of the stutter.
Stutters are the extra products of microsatellite marker amplification. For dinucleotide
markers specific to all loci in the Cordis Cattle set, it is typical for the stutter to be -2 base
pairs relative to the main product. The intensity of the stutter signal can reach up to 50% of
the intensity of the allele product. If the difference in allele length is 2 base pairs, the stutter of
the longer allele overlaps with the shorter allele, significantly increasing the signal level
The results of the conducted research can be effectively used in genetic expertise, as well
as in fundamental and applied studies aimed at examining the allele pool status and dynamics
of animal populations, which are agricultural objects. It can also contribute to the
development of methods for managing the gene pool of breeds. Through the identification of
animal biomaterials, it will be possible to effectively organize the breeding of economically
valuable animals, increase their productivity, and protect their health.
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References:
Используемая литература:
Foydalanilgan adabiyotlar:
1.
https://biomolecula.ru/articles/kriminalistika-molekuliarno-geneticheskaia-ekspertiza
2.
The evaluation of forensic DNA evidence. Washington (DC): National Academies Press,
1996
3.
Instruction for use of the SilicSorbNA kit.
4.
Instruction for use of the COrDIS Cattle kit.
5.
S.A. Ataxodjayev and others “Forensic DNA Expertise of Humans.” Educational manual,
2011.
6.
Saitova N.S. “The Importance of Animal DNA in Criminal Investigation,” Tashkent,
Seminar Proceedings titled “Current Issues in Forensic Biology Expertise,” April 25-26, 2024.
