Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

Browse

Filters

2021 - 20252

Settings

Has files: YesSubject: search.filters.subject.Bos taurus

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    An Increase in Male Recombination Rate With Age in Dairy Cattle Is Heritable and Polygenic
    (John Wiley and Sons Ltd, 2025-06-14) Jade E; Littlejohn MD; Eketone K; Spelman RJ; Stapley J; Santure AW
    Meiotic recombination is an essential process for shuffling genetic diversity in sexually reproducing organisms, can vary within and between individuals in response to intrinsic and extrinsic factors, and can be heritable. Interestingly, recombination rate has been found to vary with age in some species, but to date, there have been no assessments of the heritability and genetic architecture of this age effect. Here, we leverage a large pedigree of SNP chip-genotyped Aotearoa New Zealand Holstein-Friesian and Jersey dairy cattle to test for an effect of age on male recombination rate, the heritability of recombination rate and of any such age effect on recombination, and the genetic architecture underlying these two phenotypes. We found a significant, albeit small, increase in the average number of male autosomal recombinations with age. Consistent with previous studies, we found moderate heritability (h2 ≈ 0.15) of sire recombination rate and detected association with several regions on chromosome 10 encompassing genes such as REC8, REC114, RNF212B and NEK9. Further, we found novel evidence of some heritability (h2 ≈ 0.05) in the rate of change in recombination with age in sires. Variation in the rate of change with age is likely also polygenic, but there is a region on chromosome 1 that is weakly associated with the rate of change. It is unclear whether the heritability of age-related recombination rate change is widespread across species, and we encourage studies in other taxa to assess its prevalence and evolutionary significance.
  • Thumbnail Image
    Item
    Identification of genetic variants the CCKAR gene and based on body measurement and carcass quality characteristics in Qinchuan beef cattle (Bos taurus)
    (Elsevier B.V., 2021-05) Nurgulsim K; Raza SHA; Khan R; Shah MA; Jahejo AR; Batool U; Hongbao W; Zhigerbayevich KN; Schreurs N; Zan L
    Background: This study aimed to explore genetic polymorphisms of the CCKAR gene and their relationship with the growth and development of Qinchuan cattle which could be used as molecular markers for the improvement of the breeding of Qinchuan cattle. Results: Here, we have identified seven single nucleotide polymorphisms (SNPs) at loci g. 1463 C>G; g. 1532 T>A; g. 1570 G>A; g. 1594 C>A; g. 1640 T>C; g. 1677 G>C; and g. 1735 C>T in the coding region of the bovine CCKAR gene. The frequencies identified on allelic and genotypic characteristics have shown that all seven SNPs diverged from the Hardy-Weinberg-Equilibrium. The SNP2, SNP3, SNP6 and SNP7 had the lowest polymorphism information content values, and remaining SNPs were found to be moderate (0.25 < PIC < 0.50). The genotype CG in SNP1 at loci g.1463 C>G had the greatest association with WH, HW, CD and CCF, while the genotype TA at the very same loci was associated with BFT, ULA and IMF content in Qinchuan cattle. The CCKAR gene expression level in adipose tissue, small intestine, liver and skeleton muscle was found to be higher, whereas, the expression level of mRNA in organs of other digestive system including reticulum, abomasum and omasum was moderate. Some expression of CCKAR mRNA was found in the large intestine, kidney and rumen. Conclusion: In summary, our finding suggested that the CCKAR gene could be used as a potential candidate for the improvement of carcass quality and body measurements of Qinchuan cattle.