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Genetic differentiation of Mexican Holstein cattle and its relationship with Canadian and U.S. Holsteins.

García-Ruiz A, Ruiz-López Fde J, Van Tassell CP, Montaldo HH, Huson HJ - Front Genet (2015)

Bottom Line: Admixture analysis differentiated between the genetic composition of the Conv and Lowi systems, and five ancestry groups associated to sire's country of origin were identified.The minimum distance between markers to estimate a useful LD was found to be 54.5 kb for the Mexican HO populations.Mexican HO cattle in Conv and Lowi populations share common ancestry with CAN + USA but have different genetic signatures.

View Article: PubMed Central - PubMed

Affiliation: Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México Ajuchitlán, Mexico.

ABSTRACT
The Mexican Holstein (HO) industry has imported Canadian and US (CAN + USA) HO germplasm for use in two different production systems, the conventional (Conv) and the low income (Lowi) system. The objective of this work was to study the genetic composition and differentiation of the Mexican HO cattle, considering the production system in which they perform and their relationship with the Canadian and US HO populations. The analysis included information from 149, 303, and 173 unrelated or with unknown pedigree HO animals from the Conv, Lowi, and CAN + USA populations, respectively. Canadian and US Jersey (JE) and Brown Swiss (BS) genotypes (162 and 86, respectively) were used to determine if Mexican HOs were hybridized with either of these breeds. After quality control filtering, a total of 6,617 out of 6,836 single nucleotide polymorphism markers were used. To describe the genetic diversity across the populations, principal component (PC), admixture composition, and linkage disequilibrium (LD; r(2) ) analyses were performed. Through the PC analysis, HO × JE and HO × BS crossbreeding was detected in the Lowi system. The Conv system appeared to be in between Lowi and CAN + USA populations. Admixture analysis differentiated between the genetic composition of the Conv and Lowi systems, and five ancestry groups associated to sire's country of origin were identified. The minimum distance between markers to estimate a useful LD was found to be 54.5 kb for the Mexican HO populations. At this average distance, the persistence of phase across autosomes of Conv and Lowi systems was 0.94, for Conv and CAN + USA was 0.92 and for the Lowi and CAN + USA was 0.91. Results supported the flow of germplasm among populations being Conv a source for Lowi, and dependent on migration from CAN + USA. Mexican HO cattle in Conv and Lowi populations share common ancestry with CAN + USA but have different genetic signatures.

No MeSH data available.


Related in: MedlinePlus

Principal component analysis plot of the Mexican Holstein cattle of the conventional (Conv) and low income system (Lowi), the North American Holstein (CAN + USA), Jersey (JE) and Brown Swiss (BS).
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Figure 2: Principal component analysis plot of the Mexican Holstein cattle of the conventional (Conv) and low income system (Lowi), the North American Holstein (CAN + USA), Jersey (JE) and Brown Swiss (BS).

Mentions: In this study, the first three of 625 components of PCA explained 13% of the observed variation. Population differentiation is observed between the Mexican Lowi and Conv subgroups and the Canadian and US HO cattle (Figure 1), despite many common ancestors across these groups. The Conv system seems to be intermediate between the Lowi and CAN + USA groups. Neither Mexican system demonstrated a clustering of animals by country of origin of the sire. PCs for all North American HO cattle along with the JE and BS cattle are shown in Figure 2, where the individuals were color coded by breed and population of origin. Crossbred individuals derived from HO and JE or BS were represented by points located between those pure breeds. Crossbreeding was rare in the Conv herds but was much more common in the Lowi systems with a higher proportion of crossing to JE influenced animals than BS.


Genetic differentiation of Mexican Holstein cattle and its relationship with Canadian and U.S. Holsteins.

García-Ruiz A, Ruiz-López Fde J, Van Tassell CP, Montaldo HH, Huson HJ - Front Genet (2015)

Principal component analysis plot of the Mexican Holstein cattle of the conventional (Conv) and low income system (Lowi), the North American Holstein (CAN + USA), Jersey (JE) and Brown Swiss (BS).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321612&req=5

Figure 2: Principal component analysis plot of the Mexican Holstein cattle of the conventional (Conv) and low income system (Lowi), the North American Holstein (CAN + USA), Jersey (JE) and Brown Swiss (BS).
Mentions: In this study, the first three of 625 components of PCA explained 13% of the observed variation. Population differentiation is observed between the Mexican Lowi and Conv subgroups and the Canadian and US HO cattle (Figure 1), despite many common ancestors across these groups. The Conv system seems to be intermediate between the Lowi and CAN + USA groups. Neither Mexican system demonstrated a clustering of animals by country of origin of the sire. PCs for all North American HO cattle along with the JE and BS cattle are shown in Figure 2, where the individuals were color coded by breed and population of origin. Crossbred individuals derived from HO and JE or BS were represented by points located between those pure breeds. Crossbreeding was rare in the Conv herds but was much more common in the Lowi systems with a higher proportion of crossing to JE influenced animals than BS.

Bottom Line: Admixture analysis differentiated between the genetic composition of the Conv and Lowi systems, and five ancestry groups associated to sire's country of origin were identified.The minimum distance between markers to estimate a useful LD was found to be 54.5 kb for the Mexican HO populations.Mexican HO cattle in Conv and Lowi populations share common ancestry with CAN + USA but have different genetic signatures.

View Article: PubMed Central - PubMed

Affiliation: Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México Ajuchitlán, Mexico.

ABSTRACT
The Mexican Holstein (HO) industry has imported Canadian and US (CAN + USA) HO germplasm for use in two different production systems, the conventional (Conv) and the low income (Lowi) system. The objective of this work was to study the genetic composition and differentiation of the Mexican HO cattle, considering the production system in which they perform and their relationship with the Canadian and US HO populations. The analysis included information from 149, 303, and 173 unrelated or with unknown pedigree HO animals from the Conv, Lowi, and CAN + USA populations, respectively. Canadian and US Jersey (JE) and Brown Swiss (BS) genotypes (162 and 86, respectively) were used to determine if Mexican HOs were hybridized with either of these breeds. After quality control filtering, a total of 6,617 out of 6,836 single nucleotide polymorphism markers were used. To describe the genetic diversity across the populations, principal component (PC), admixture composition, and linkage disequilibrium (LD; r(2) ) analyses were performed. Through the PC analysis, HO × JE and HO × BS crossbreeding was detected in the Lowi system. The Conv system appeared to be in between Lowi and CAN + USA populations. Admixture analysis differentiated between the genetic composition of the Conv and Lowi systems, and five ancestry groups associated to sire's country of origin were identified. The minimum distance between markers to estimate a useful LD was found to be 54.5 kb for the Mexican HO populations. At this average distance, the persistence of phase across autosomes of Conv and Lowi systems was 0.94, for Conv and CAN + USA was 0.92 and for the Lowi and CAN + USA was 0.91. Results supported the flow of germplasm among populations being Conv a source for Lowi, and dependent on migration from CAN + USA. Mexican HO cattle in Conv and Lowi populations share common ancestry with CAN + USA but have different genetic signatures.

No MeSH data available.


Related in: MedlinePlus