Evaluating markers in selected genes for association with functional longevity of dairy cattle

Abstract

BackgroundLongevity expressed as the number of days between birth and death is a trait of great importance for both human and animal populations. In our analysis we use dairy cattle to demonstrate how the association of Single Nucleotide Polymorphisms (SNPs) located within selected genes with longevity can be modeled. Such an approach can be extended to any genotyped population with time to endpoint information available. Our study is focused on selected genes in order to answer the question whether genes, known to be involved into the physiological determination of milk production, also influence individual's survival.ResultsGenerally, the highest risk differences among animals with different genotypes are observed for polymorphisms located within the leptin gene. The polymorphism with a highest effect on functional longevity is LEP-R25C, for which the relative risk of culling for cows with genotype CC is 3.14 times higher than for the heterozygous animals. Apart from LEP-R25C, also FF homozygotes at the LEP-Y7F substitution attribute 3.64 times higher risk of culling than the YY homozygotes and VV homozygotes at LEP-A80V have 1.83 times higher risk of culling than AA homozygotes. Differences in risks between genotypes of polymorphisms within the other genes (the butyrophilin subfamily 1 member A1 gene, BTN1A1; the acyl-CoA:diacylglycerol acyltransferase 1 gene, DGAT1; the leptin receptor gene, LEPR; the ATP-binding cassette sub-family G member 2, ABCG2) are much smaller.ConclusionsOur results indicate association between LEP and longevity and are very well supported by results of other studies related to dairy cattle. In view of the growing importance of functional traits in dairy cattle, LEP polymorphisms should be considered as markers supporting selection decisions. Furthermore, since the relationship between both LEP polymorphism and its protein product with longevity in humans is well documented, with our result we were able to demonstrate that livestock with its detailed records of family structure, genetic, and environmental factors as well as extensive trait recording can be a good model organism for research aspects related to humans.

Bioinformatics and Computational Biology in Poland

“…At the same faculty, a group led by Małgorzata Bogdan works in the area of statistical human genomics, in particular on the problem of locating quantitative trait loci (QTL) [81]. At the Faculty of Biology and Animal Science of the Wrocław University of Environmental and Life Sciences, Joanna Szyda's group works on statistic genomics of animals [82]. Stanisław Cebrat's group at the Faculty of Biotechnology of the University of Wrocław is working in the area of theoretical and computational genomics, e.g., on Monte Carlo simulations of genome and population evolution [26], [83].…”

Longevity in Dairy Cattle

“…In fact, just LEP and polymorphisms were associated with longevity in Polish Holstein-Friesian cows, being considering consistent marker for longevity in this breed [20]. A single nucleotide polymorphic of the pituitary specific transcription factor 1 with domain POU gene (POUlFl) was associated with improved longevity and milk product traits in Holstein cows.…”

LEP gene allelic polymorphism in a subpopulation of Ayrshire cattle

“…For instance, cows bearing the CC genotype (R25C polymorphism of leptin gene) demonstrated a 3.14 fold higher risk of rejection compared to animals with the heterozygous genotype, while cows with the FF genotype (Y7F polymorphism of leptin gene) demonstrated a 3.64 fold higher risk of rejected compared to cows with the YY genotype [6]. The influence of LEP A80V poly morphism on the duration of economical use and the level of animals' profitability was also reported previ ously [1,6].…”

“…The frequencies of LEP gene polymorphic variants (R25C, Y7F, A80V) were studied in several samples of Holstein animals (n = 1975) [1,6].…”

“…Thus, combi nations of "weak" + "strong" genotype and "strong" + "weak" genotypes play a role in productive longevity, while other combinations do not (the CC genotype is worse than RR, while the FF genotype is worse than YY [6]). …”