Genetic diversity among Canadienne, Brown Swiss, Holstein and Jersey cattle based on mitochondrial D-loop sequence variation Academic Article uri icon

abstract

  • Polymorphisms creating 36 unique haplotypes were observed with in breeds at 55 sites in the displacement loop (D-loop) region of the mitochondrial DNA (mtDNA) consisting of 814 bp. The majority (56%) of the differences observed were the result of nucleotide substitution events with 19 transitions, 12 transversions, 11 deletions, 12 insertions and 1 inversion. In all cases, the insertions and deletions were of a single nucleotide. Canadienne cattle were found to have 60% unique haplotypes within the population compared to 89% in Brown Swiss, 90% in Holstein and 100% in Jersey cattle, possibly reflecting the narrow genetic base in the Canadienne breed. The degree of sequence divergence in the D-loop region of mtDNA was based on samples from 20 Canadienne, 9 Brown Swiss, 10 Holstein and 10 Jersey cattle and a phylogenetic analysis showed that these cattle (Bos taurus) were not evolutionarily distinct. All four breeds grouped together when a strict consensus tree was generated. Intra-breed variability proved to be high for the Canadienne, Holstein and Jersey breeds (5773%) but not the Brown Swiss breed (29%). The Canadienne and Brown Swiss (45%), and Brown Swiss and Holstein (43%) showed the lowest degree of inter-breed variability. The greatest variability among the four breeds was between Canadienne and Jersey (80%) cattle. These findings question the validity of phenotypic assessment of genetic diversity, such as Canadienne cattle being described as Black Jersey. Key words: Genetic distance, phylogenetic analysis, D-loop sequence, cattle

published proceedings

  • CANADIAN JOURNAL OF ANIMAL SCIENCE

author list (cited authors)

  • Hansen, C., Shrestha, J., Parker, R. J., Crow, G. H., McAlpine, P. J., & Derr, J. N.

citation count

  • 1

complete list of authors

  • Hansen, C||Shrestha, JNB||Parker, RJ||Crow, GH||McAlpine, PJ||Derr, JN

publication date

  • January 1, 2003 11:11 AM