Application of disease-associated differentially expressed genes – Mining for functional candidate genes for mastitis resistance in cattle

Abstract

-In this study the mRNA differential display method was applied to identify mastitisassociated expressed DNA sequences based on different expression patterns in mammary gland samples of non-infected and infected udder quarters of a cow. In total, 704 different cDNA bands were displayed in both udder samples. Five hundred-and-thirty two bands, (75.6%) were differentially displayed. Ninety prominent cDNA bands were isolated, re-amplified, cloned and sequenced resulting in 87 different sequences. Amongst the 19 expressed sequence tags showing a similarity with previously described genes, the majority of these sequences exhibited homology to protein kinase encoding genes (26.3%), to genes involved in the regulation of gene expression (26.3%), to growth and differentiation factor encoding genes (21.0%) and to immune response or inflammation marker encoding genes (21.0%). These sequences were shown to have mastitis-associated expression in the udder samples of animals with and without clinical mastitis by quantitative RT-PCR. They were mapped physically using a bovine-hamster somatic cell hybrid panel and a 5000 rad bovine whole genome radiation hybrid panel. According to their localization in QTL regions based on an established integrated marker/gene-map and their disease-associated expression, four genes (AHCY, PRKDC, HNRPU, OSTF1) were suggested as potentially involved in mastitis defense. mastitis / expressed sequence tag / gene expression / cattle / RH mapping

Promoter variants at AP2 box region of Hsp70.1 affect thermal stress response and milk production traits in Frieswal cross bred cattle

“…The greater ability of wild type promoter genotypes to express hsp70.1 than the deletion mutant genotypes, as observed in our study, may partially explain the better milk production traits of wild type genotypes. These findings indirectly agree with Schwerin et al (2003a), who reported the association of the same SNP within hsp70 promoter to the shorter productive life. Previous studies highlighted the role of polymorphism within hsp70 promoter region to the reproductive parameters including pregnancy rate, calf weaning weights and fertility in dairy cattle (Bank et al, 2007;Rosenkrans et al, 2010;Starkey et al, 2007).…”

“…It was found that heterozygous cytosine deletion mutant genotypes (C−) form majority with the absence of homozygous cytosine deletion mutant genotypes (−−) in tested population. Previously the polymorphism at same position had reported the presence of all three genotypes in Holstein dairy cows (Basirico et al, 2011;Schwerin et al, 2003a). Since the present study involves a cross breed Frieswal (Holstein × Sahiwal) population, it supports the concept that the genotype and allele frequency of the specific SNP may not be repeatable in different populations of same breed or in different breeds.…”

“…Similarly the functional analysis was done to understand the effect of promoter sequence variants on AP2 factor binding and subsequently the stress induced expression of Hsp70 genes (Schwerin et al, 2001). Polymorphisms within promoters, altering the potential cis acting elements, were also associated with relative stress tolerance in terms of "productive life time" in Holstein breed of cattle (Schwerin et al, 2003a). Considering these facts, it is assumed that the polymorphism within the promoter of Hsp70.1 gene may strongly be associated with the thermotolerance and other production traits in dairy cattle.…”

Application of Selection Mapping to Identify Genomic Regions Associated with Dairy Production in Sheep

“…The POFUT1 (protein O-fucosyltransferase 1) gene plays a crucial role in Notch signaling, which regulates mammary stem cell function and luminal cell-fate commitment [44]. TFAP2C (transcription factor AP-2 gamma; activating enhancer binding protein 2 gamma) is involved in mammary development, differentiation, and oncogenesis playing a critical role in gene regulation in hormone responsive breast cancer [45], and AHCY (adenosylhomocysteinase) has been suggested as potentially involved in mastitis defense based on its disease-associated expression [46]. Another positional candidate gene for this core region is the GHRH (growth hormone-releasing hormone) gene.…”

Genetic factors affecting susceptibility to udder pathogens

“…3, 4, 9, 11, 18 and 27, which recommends them as candidate chromosomes for fine mapping. This was done by Brunner et al (2003) and Mömke et al (2005) for Chr. 18.…”