The differentiation of prehypertrophic into hypertrophic chondrocytes drives an OA-remodeling program and IL-34 expression.

Objectives: We hypothesize that chondrocytes from the deepest articular cartilage layer are pivotal in maintaining cartilage integrity and that the modification of their prehypertrophic phenotype to a hypertrophic phenotype will drive cartilage degradation in osteoarthritis.

Design: Murine immature articular chondrocytes (iMACs) were successively cultured into three different culture media to induce a progressive hypertrophic differentiation. Chondrocyte were phenotypically characterized by whole-genome microarray analysis.

Characterization of the various functional pathways elicited by synthetic agonists or antagonists at the melatonin MT and MT receptors.

Melatonin is a neurohormone that translates the circadian rhythm to the peripheral organs through a series of binding sites identified as G protein-coupled receptors MT and MT. Due to minute amounts of receptor proteins in target organs, the main tool of studies of the melatoninergic system is recombinant expression of the receptors in cellular hosts. Although a number of studies exist on these receptors, studies of several signaling pathways using a large number of melatoninergic compounds are rather limited.

Gene expression profiling during hibernation in the European hamster.

Hibernation is an exceptional physiological response to a hostile environment, characterized by a seasonal period of torpor cycles involving dramatic reductions of body temperature and metabolism, and arousal back to normothermia. As the mechanisms regulating hibernation are still poorly understood, here we analysed the expression of genes involved in energy homeostasis, torpor regulation, and daily or seasonal timing using digital droplet PCR in various central and peripheral tissues sampled at different stages of torpor/arousal cycles in the European hamster. During torpor, the hypothalamus exhibited strongly down-regulated gene expression, suggesting that hypothalamic functions were reduced during this period of low metabolic activity.

Maternal organism and embryo biosensoring: insights from ruminants.

In terms of contribution to pregnancy, the mother not only produces gametes, but also hosts gestation, whose progression in the uterus is conditioned by early events during implantation. In ruminants, this period is associated with elongation of the extra-embryonic tissues, gastrulation of the embryonic disk and cross-talk with the endometrium. Recent data have prompted the need for accurate staging of the bovine conceptus and shown that asynchrony between elongation and gastrulation processes may account for pregnancy failure.

Genetic tools to improve reproduction traits in dairy cattle.

Fertility is a major concern in the dairy cattle industry and has been the subject of numerous studies over the past 20 years. Surprisingly, most of these studies focused on rough female phenotypes and, despite their important role in reproductive success, male- and embryo-related traits have been poorly investigated. In recent years, the rapid and important evolution of technologies in genetic research has led to the development of genomic selection.