Subject(s)
Magnetic Resonance Imaging/methods , Matrix Metalloproteinase 3/blood , Mucocutaneous Lymph Node Syndrome/complications , Osteoarthritis, Knee/etiology , Biomarkers/blood , Child, Preschool , Diagnosis, Differential , Female , Follow-Up Studies , Humans , Mucocutaneous Lymph Node Syndrome/diagnosis , Mucocutaneous Lymph Node Syndrome/enzymology , Osteoarthritis, Knee/diagnosis , Osteoarthritis, Knee/enzymologyABSTRACT
Previous studies on early female mouse embryos revealed the presence of two kinds of inactive X chromosomes, one replicating late and the other early in the DNA synthetic period. The X chromosome that replicates early is of special interest because of its paternal origin, preferential occurrence in trophectoderm and primitive endoderm derivatives, and programmed shift to the late replicator. This study by BrdU labeling and acridine orange fluorescence staining was undertaken to examine whether the inactive X chromosome behaves in a similar manner in other laboratory mammals. In rat embryos the paternal X chromosome was found to show the same behavior in extraembryonic tissues. Early replicating chromosomes were also found in the extraembryonic regions of Chinese hamster and rabbit embryos, although their parental origin could not be determined due to the absent of X chromosome polymorphism in these species. Probably the early replicating X chromosome occurs commonly in mammals. Its functional significance is unknown.
