Milk protein polymorphisms and casein haplotypes in Blanco Orejinegro cattle of Colombia

Ano: 2024 | Volume: 1 | Número: 23

Autores: Juan C Rincon-Florez, Maryi N Pulido-Hoyos M, Darwin Y Hernandez-Herrera

Palavras-chave: beta-lactoglobulin; cow´s milk; CSN gene variants; milk proteins.

Resumo Português:

O objetivo foi determinar a variação genética nos genes CSN1S1, CSN2, CSN1S2, CSN3 e LGB em bovinos Blanco Orejinegro. 419 animais de 15 rebanhos foram genotipados com chips GGP Bovine 150 K (n= 70) e 50 K (n= 349). Foram obtidas informações de 43 SNPs nos genes mencionados e as variantes proteicas *B, *C e *D de αS1-CN; *A1, *A2, *B, *H2 e *F de β-CN; *A e *D de αS2-CN, *A, *A1, *B, *I e *H de κ-CN e *A, *B, *C, *D, *E, *F e *H de β-LG foram reconstruídas. As frequências alélicas e genotípicas foram estimadas para SNPs e para variantes de proteínas; o equilíbrio de Hardy-Weinberg e os valores de F_ST foram avaliados para cada um dos SNPs sob diferentes critérios de estruturação. Os valores de LD e as frequências haplotípicas foram estimados para as caseínas. As variantes mais frequentes foram CSN1S1*B (0.804), CSN2*A2 (0.509), CSN1S2*A (0.997), CSN3*A (0.679) e β-LG*B (0.657). Nenhuma das variantes apresentou desvios da HWE, mas o alelo CSN2*A2 apresentou uma leve tendência de aumento ao longo do tempo. Os valores de F_ST foram baixos (0.035) independentemente dos critérios de estruturação. Foram encontrados 28 haplótipos CSN1S1-CSN2-CSN1S2-CSN3, 22 deles com frequências <5%; os três mais frequentes foram BB-A¹A²-AA-AA-AA-AA (16.6%), BB-A¹A²-AA-AA-AA-AB (14.1%) e BB-A²A²-AA-AA-AA (10.1%). Foi relatado um bom potencial do gado BON para produzir leite de alta qualidade com valor funcional.

Resumo Inglês:

The aim was to determine the genetic variation in the CSN1S1, CSN2, CSN1S2, CSN3 and LGB genes in Blanco Orejinegro cattle. 419 animals from 15 herds were genotyped with GGP Bovine 150 K (n= 70) and 50 K (n= 349) chips. Information was obtained from 43 SNPs in the mentioned genes and protein variants *B, *C and *D of α_S1-CN; *A¹, *A², *B, *H² and *F of β-CN; *A and *D of α_S2-CN, *A, *A¹, *B, *I and *H of κ-CN and *A, *B, *C, *D, *E, *F and *H of β-LG were reconstructed. Allele and genotypic frequencies were estimated for SNPs and for protein variants; Hardy-Weinberg equilibrium and F_ST values were evaluated for each of the SNPs under different structuring criteria. LD values and haplotypic frequencies were estimated for caseins. The most frequent variants were CSN1S1*B (0.804), CSN2*A² (0.509), CSN1S2*A (0.997), CSN3*A (0.679) and β-LG*B (0.657). None of the variants showed deviations from HWE, but the CSN2*A² allele showed a slight increasing trend over time. The F_ST values were low (0.035) regardless of the structuring criteria. Twenty-eight CSN1S1-CSN2-CSN1S2-CSN3 haplotypes were found, 22 of them with frequencies <5%; the three most frequent were BB-A¹A²-AA-AA-AA-AA (16.6%), BB-A¹A²-AA-AA-AA-AB (14.1%) and BB-A²A²-AA-AA-AA (10.1%). A good potential of BON cattle to produce high quality milk with functional value was reported.