Project description:Previous studies have demonstrated relative deficiencies of repair tissue within articular lesions when compared to articular cartilage. While cells occupying the lesions might be of mesenchymal origin, they do not recapitulate differentiation to the chondrogenic phenotype of normal articular chondrocytes. Nevertheless, attributes of repair tissue appear similar to chondrocytes and their precursors at various other different states. We hypothesized that analyses of gene expression profiles for these other cell phenotypes would elucidate the identity of repair tissue cells. Total RNA was isolated from repair tissue samples, neonatal articular cartilage, primary articular chondrocytes maintained in monolayer culture and passaged weekly over 28 days, and bone marrow stromal cells expanded to 80% confluence in monolayer culture. Total RNA was linearly amplified and applied to a 9413-probe set equine-specific cDNA microarray. Four repair tissue samples were compared with a dye-swap experimental design to four samples from each of the three other cell populations for a total of twelve comparisons, or twenty-four slides. Differential expression of genes of interest was validated by real-time quantitative polymerase chain reaction. Statistical analysis revealed that a total of 934 (9.9%), 1839 (19.5%), and 940 (10.0%) probe sets were differentially expressed for the bone marrow stromal cells versus repair tissue, de-differentiated chondrocytes versus repair tissue, and neonatal articular chondrocytes versus repair tissue comparisons, respectively. Transcriptional and translational machinery gene ontological categories were over-represented in transcripts demonstrating stable expression amongst the three comparisons. Biomarkers typically associated with normal articular cartilage and fibrocartilage repair tissue comprised much of the genes with the greatest levels of differential expression amongst the three comparisons. Overall, the profiles indicated that repair cells were more chondrogenic than bone marrow stromal cells and de-differentiated chondrocytes. However, transcript levels of key biomarkers and growth factors for repair tissue cells four months post-operatively fell far short of those of neonatal articular chondrocytes destined to undergo normal cartilage maturation.
Project description:Comparative analysis of gene expression profiles in the mammary glands of lactating and nonlactating mares at the second month of gestation
Project description:A comparative gene map of the horse genome composed of 127 loci was assembled based on the new assignment of 68 equine type I loci and on data published previously. PCR primers based on consensus gene sequences conserved across mammalian species were used to amplify markers for assigning 68 equine type I loci to 27 horse synteny groups established previously with a horse-mouse somatic cell hybrid panel (SCHP, UC Davis). This increased the number of coding genes mapped to the horse genome by over 2-fold and allowed refinements of the comparative mapping data available for this species. In conjunction with 57 previous assignments of type I loci to the horse genome map, these data have allowed us to confirm the assignment of 24 equine synteny groups to their respective chromosomes, to provisionally assign nine synteny groups to chromosomes, and to further refine the genetic composition established with Zoo-FISH of two horse chromosomes. The equine type I markers developed in this study provide an important resource for the future development of the horse linkage and physical genome maps.
Project description:Although several tendon-selective genes exist, they are also expressed in other musculoskeletal tissues. As cell and tissue engineering is reliant on specific molecular markers to discriminate between cell types, tendon-specific genes need to be identified. In order to accomplish this, we have used RNA sequencing (RNA-seq) to compare gene expression between tendon, bone, cartilage and ligament from horses. We identified several tendon-selective gene markers, and established eyes absent homolog 2 (EYA2) and a G-protein regulated inducer of neurite outgrowth 3 (GPRIN3) as specific tendon markers using RT-qPCR. Equine tendon cells cultured as three-dimensional spheroids expressed significantly greater levels of EYA2 than GPRIN3, and stained positively for EYA2 using immunohistochemistry. EYA2 was also found in fibroblast-like cells within the tendon tissue matrix and in cells localized to the vascular endothelium. In summary, we have identified EYA2 and GPRIN3 as specific molecular markers of equine tendon as compared to bone, cartilage and ligament, and provide evidence for the use of EYA2 as an additional marker for tendon cells in vitro.
Project description:Humans have domesticated many kinds of animals in their history. Dogs and horses have particularly close relationships with humans as cooperative partners. However, fewer scientific studies have been conducted on cognition in horses compared to dogs. Studies have shown that horses cross-modally distinguish human facial expressions and recognize familiar people, which suggests that they also cross-modally distinguish human emotions. In the present study, we used the expectancy violation method to investigate whether horses cross-modally perceive human emotions. Horses were shown a picture of a human facial expression on a screen, and they then heard a human voice from the speaker before the screen. The emotional values of the visual and auditory stimuli were the same in the congruent condition and different in the incongruent condition. Horses looked at the speaker significantly longer in the incongruent condition than in the congruent condition when they heard their caretaker's voices but not when they heard the stranger voice. In addition, they responded significantly more quickly to the voice in the incongruent condition than in the congruent one. To the best of our knowledge, this is the first study to show that horses cross-modally recognized the emotional states of their caretakers and strangers.