Project description:We carried out a cross species cattle-sheep array comparative genome hybridization (aCGH) experiment in order to identify copy number variations (CNVs) in the sheep genome analysing animals of Italian dairy breeds (Sarda, Bagnolese, Laticauda, Massese and Valle del Belice) using a tiling oligonucleotide array with ~385,000 probes designed on the bovine genome. We identified 135 CNV regions (CNVRs) covering about 10.5 Mb of the virtual sheep genome referred to the bovine genome (0.398%) with a mean and median equal to 77.6 kb and 55.9 kb, respectively. A comparative analysis between the identified sheep CNVRs and those reported in the cattle and goat genomes indicated that overlaps between sheep and goat and sheep and cattle CNVRs are highly significant (P<0.0001) suggesting that several chromosome regions might contain recurrent interspecies CNVRs. Many sheep CNVs affect genes with important biological functions. Further studies are needed to evaluate the functional relevance of these CNVs.
Project description:Staphylococcus aureus is recognized worldwide as a major pathogen causing clinical or subclinical intramammary infections in all the dairy species (sheep, goats and cows). The present study was designed to comparatively investigate 65 S. aureus isolates recovered from dairy sheep and S. aureus suclinical mastitis from cows (n=21) and goats (n=22), for the presence of 190 putative virulence determinants with a single-dye DNA microarray and PCR. The probes (65 mer) were mainly designed from the S. aureus Mu50. The extracted DNA of each strain was labelled with Cy5. The microarray results were validated with PCR.The genomic comparative study with the DNA microarrays showed lineage and species specificity genes leading to the host-specific pathogenic traits of S. aureus in dairy species.
Project description:We carried out a cross species cattle-sheep array comparative genome hybridization (aCGH) experiment in order to identify copy number variations (CNVs) in the sheep genome analysing animals of Italian dairy breeds (Sarda, Bagnolese, Laticauda, Massese and Valle del Belice) using a tiling oligonucleotide array with ~385,000 probes designed on the bovine genome. We identified 135 CNV regions (CNVRs) covering about 10.5 Mb of the virtual sheep genome referred to the bovine genome (0.398%) with a mean and median equal to 77.6 kb and 55.9 kb, respectively. A comparative analysis between the identified sheep CNVRs and those reported in the cattle and goat genomes indicated that overlaps between sheep and goat and sheep and cattle CNVRs are highly significant (P<0.0001) suggesting that several chromosome regions might contain recurrent interspecies CNVRs. Many sheep CNVs affect genes with important biological functions. Further studies are needed to evaluate the functional relevance of these CNVs. In this study we made use of the high conservation and homology between the cattle and sheep genomes determined by their phylogenetic closeness to identify CNVs in sheep applying the same approach we carried out to identify CNVs in the goat genome. We used a custom tiling array including ~385,000 oligonucleotide probes designed on the Btau_4.0 version of the Bos taurus genome assembly and analysed genomic DNA samples of 11 sheep belonging to 6 different Italian dairy sheep breeds (2 Sarda, 2 Bagnolese, 2 Comisana, 2 Massese, 2 Laticauda and 1 Valle del Belice) compared to the reference DNA of another Sarda sheep.
Project description:Milk and dairy products are an essential food and an economic resource in many countries. Milk component synthesis and secretion by the mammary gland involve expression of a large number of genes whose nutritional regulation remains poorly defined. We aim at understanding the genomic influence on milk quality and synthesis by comparing two sheep breeds, with different milking attitude, Sarda and Gentile di Puglia, using sheep-specific microarray technology. From sheep ESTs deposited at NCBI, we generated the first annotated microarray developed for sheep with a covering of most of the genome.
Project description:This study evaluated the evolution of the host defensive molecular mechanisms triggered by mastitis caused by external agents or events, since it is known that mammary gland infections constitute a significant challenge in dairy sheep, impacting productivity and welfare. Thus, the aim of this study was to examine the transcriptomic response of the sheep mammary gland to an Escherichia coli lipopolysaccharide (LPS) inoculation using temporal RNA-Seq analysis.
Project description:Ovine mastitis is defined as the inflammation of the sheep udder, most commonly caused in response to intramammary infections. Based on the occurrence of clinical signs, mastitis is characterized as either clinical or subclinical (SCM). The impact of ovine SCM on the overall sustainability of dairy sheep farms has been documented underpinning the significance of efficient diagnosis. Although SCM can be detected in cows, the performance and the validity of the methods used do not transfer in dairy sheep. This fact challenges the development of evidence-based ovine udder health management protocols and renders the detection and control of ovine mastitis rather problematic. Currently, cell culture-based models are being successfully used in biomedical studies and have also been effectively used in the case of bovine mastitis. The objective of the present study was to culture ovine primary mammary cells for the development of 2D and 3D cell culture-based models for the study of ovine SCM. Cells were infected by mastitis-inducing pathogens mimicking the pathogenesis of SCM as derived by natural intramammary infections. The secreted proteins were subjected to mass-spectrometry resulting in the identification of 79 distinct proteins. Among those, several had already been identified in healthy or mastitic milk, while others were detected for the first time in the ovine mammary secretome. The development of cell-based models for the early detection and the overall study of SCM has the potential to be applicable and beneficial for the udder health management in dairy sheep.
Project description:Milk and dairy products are an essential food and an economic resource in many countries. Milk component synthesis and secretion by the mammary gland involve expression of a large number of genes whose nutritional regulation remains poorly defined. We aim at understanding the genomic influence on milk quality and synthesis by comparing two sheep breeds, with different milking attitude, Sarda and Gentile di Puglia, using sheep-specific microarray technology. From sheep ESTs deposited at NCBI, we generated the first annotated microarray developed for sheep with a covering of most of the genome. Whole tissue samples of mammary gland were collected from 4 lactating individuals of two sheep (Ovis aries) breeds, Gentile di Puglia and Sarda. Biopsies of lactating mammary tissue were taken at two lactation stages (first record, stage 01: 6 days after lambing; second record, stage 02: 44 days after lambing) in both breeds. Tissues from mammary gland were immersed in RNAlater (Sigma) immediately after biopsy and stored at -20°C.
Project description:To investigate the molecular bases of diet induced differences in milk composition, we collected milk from mid lactation dairy ewes and after 3 weeks of diet supplementation with extruded linseed. RNAs were isolated from milk somatic cells isolated from milk of 3 sheep and Illumina RNA sequencing was performed to analyze RNA synthesis in these cells.