Comparison of five different RNA sources to examine the lactating bovine mammary gland transcriptome using RNA-Sequencing.

The objective of this study was to examine five different sources of RNA, namely mammary gland tissue (MGT), milk somatic cells (SC), laser microdissected mammary epithelial cells (LCMEC), milk fat globules (MFG) and antibody-captured milk mammary epithelial cells (mMEC) to analyze the bovine mammary gland transcriptome using RNA-Sequencing. Our results provide a comparison between different sampling methods (invasive and non-invasive) to define the transcriptome of mammary gland tissue and milk cells. This information will be of value to investigators in choosing the most appropriate sampling method for different research applications to study specific physiological states during lactation. One of the simplest procedures to study the transcriptome associated with milk appears to be the isolation of total RNA directly from SC or MFG released into milk during lactation. Our results indicate that the SC and MFG transcriptome are representative of MGT and LCMEC and can be used as effective and alternative samples to study mammary gland expression without the need to perform a tissue biopsy

A missense variant in the coil1A domain of the keratin 25 gene is associated with the dominant curly hair coat trait (Crd) in horse

Curly horses present a variety of curl phenotypes that are associated with various degrees of curliness of coat, mane, tail and ear hairs. Their origin is still a matter of debate and several genetic hypotheses have been formulated to explain the diversity in phenotype, including the combination of autosomal dominant and recessive alleles. Our purpose was to map the autosomal dominant curly hair locus and identify the causal variant using genome-wide association study (GWAS) and whole-genome sequencing approaches. A GWAS was performed using a Bayesian sparse linear mixed model, based on 51 curly and 19 straighthaired French and North American horses from 13 paternal families genotyped on the Illumina EquineSNP50 Bead-Chip. A single strong signal was observed on equine chromosome 11, in a region that encompasses the type I keratin gene cluster. This region was refined by haplotype analysis to a segment including 36 genes, among which are 10 keratin genes (KRT-10, -12, -20, -23, -24, -25, -26, -27, -28, -222). To comprehensively identify candidate causal variants within all these genes, whole-genome sequences were obtained for one heterozygous curly stallion and its straighthaired son. Among the four non-synonymous candidate variants identified and validated in the curly region, only variant g. 21891160G> A in the KRT25 gene (KRT25:p.R89H) was in perfect agreement with haplotype status in the whole pedigree. Genetic association was then confirmed by genotyping a larger population consisting of 353 horses. However, five discordant curly horses were observed, which carried neither the variant nor the main haplotype associated with curliness. Sequencing of KRT25 for two discordant horses did not identify any other deleterious variant, which suggests locus rather than allelic heterogeneity for the curly phenotype. We identified the KRT25: p. R89H variant as responsible for the dominant curly trait, but a second dominant locus may also be involved in the shape of hairs within North American Curly horses

Omics technologies provide new insights into the molecular physiopathology of equine osteochondrosis

Background: Osteochondrosis (OC(D)) is a juvenile osteo-articular disorder affecting several mammalian species. In horses, OC(D) is considered as a multifactorial disease and has been described as a focal disruption of endochondral ossification leading to the development of osteoarticular lesions. Nevertheless, OC(D) physiopathology is poorly understood. Affected horses may present joint swelling, stiffness and lameness. Thus, OC(D) is a major concern for the equine industry. Our study was designed as an integrative approach using omics technologies for the identification of constitutive defects in epiphyseal cartilage and/or subchondral bone associated with the development of primary lesions to further understand OC(D) pathology. This study compared samples from non-affected joints (hence lesion-free) from OC(D)-affected foals (n = 5, considered predisposed samples) with samples from OC-free foals (n = 5) considered as control samples. Consequently, results are not confounded by changes associated with the evolution of the lesion, but focus on altered constitutive molecular mechanisms. Comparative proteomics and micro computed tomography analyses were performed on predisposed and OC-free bone and cartilage samples. Metabolomics was also performed on synovial fluid from OC-free, OC(D)-affected and predisposed joints. Results: Two lesion subtypes were identified: OCD (lesion with fragment) and OC (osteochondral defects). Modulated proteins were identified using omics technologies (2-DE proteomics) in cartilage and bone from affected foals compare to OC-free foals. These were associated with cellular processes including cell cycle, energy production, cell signaling and adhesion as well as tissue-specific processes such as chondrocyte maturation, extracellular matrix and mineral metabolism. Of these, five had already been identified in synovial fluid of OC-affected foals: ACTG1 (actin, gamma 1), albumin, haptoglobin, FBG (fibrinogen beta chain) and C4BPA (complement component 4 binding protein, alpha). Conclusion: This study suggests that OCD lesions may result from a cartilage defect whereas OC lesions may be triggered by both bone and cartilage defects, suggesting that different molecular mechanisms responsible for the equine osteochondrosis lesion subtypes and predisposition could be due to a defect in both bone and cartilage. This study will contribute to refining the definition of OC(D) lesions and may improve diagnosis and development of therapies for horses and other species, including humans

Differential expression of microRNAs in synovial fluid as biomarkers of osteochondrosis in equine hock joints

Differential expression of microRNAs in synovial fluid as biomarkers of osteochondrosis in equine hock joints. 35. Conference of the International Society for Animal Genetics (ISAG

Metabolic Response of the Cerebral Cortex Following Gentle Sleep Deprivation and Modafinil Administration

STUDY OBJECTIVES: The main energy reserve of the brain is glycogen, which is almost exclusively localized in astrocytes. We previously reported that cerebral expression of certain genes related to glycogen metabolism changed following instrumental sleep deprivation in mice. Here, we extended our investigations to another set of genes related to glycogen and glucose metabolism. We also compared the effect of instrumentally and pharmacologically induced prolonged wakefulness, followed (or not) by 3 hours of sleep recovery, on the expression of genes related to brain energy metabolism. DESIGN: Sleep deprivation for 6-7 hours. SETTING: Animal sleep research laboratory. PARTICIPANTS: Adults OF1 mice. INTERVENTIONS: Wakefulness was maintained by "gentle sleep deprivation" method (GSD) or by administration of the wakefulness-promoting drug modafinil (MOD) (200 mg/kg i.p.). MEASUREMENTS AND RESULTS: Levels of mRNAs encoding proteins related to energy metabolism were measured by quantitative real-time PCR in the cerebral cortex. The mRNAs encoding protein targeting to glycogen (PTG) and the glial glucose transporter were significantly increased following both procedures used to prolong wakefulness. Glycogenin mRNA levels were increased only after GSD, while neuronal glucose transporter mRNA only after MOD. These effects were reversed after sleep recovery. A significant enhancement of glycogen synthase activity without any changes in glycogen levels was observed in both conditions. CONCLUSIONS: These results indicate the existence of a metabolic adaptation of astrocytes aimed at maintaining brain energy homeostasis during the sleep-wake cycle

Mitochondrial genome variability of 205 Arabian endurance horses

Mitochondrial genome variability of 205 Arabian endurance horses. 7th World Congress on Targeting Mitochondri

Distal control of the pig whey acidic protein (WAP) locus in trangenic mice

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