Characterization of a very rare case of living ewe-buck hybrid using classical and molecular cytogenetics

The natural occurrence of live hybrid offsprings between sheep and goats has been documented in literature, however all the studies have reported the mating of goats with rams, whereas the reciprocal cross was never documented. This study reports on a very rare case of interspecies hybridization occurred between a ewe (2n = 54, XX) and a buck (2n = 60, XY). The hybrid, born in a German flock under natural conditions, is characterised by an intermediate karyotype (2n = 57, XX). The CBA-banding has shown 3 metacentric and 54 acrocentric chromosomes, whereas the GTG- and RBA-banding have revealed that the autosomes involved in the hybrid combination were CHI1, 3; CHI2, 8 and CHI5, 11 corresponding to the metacentric chromosomes OAR1, OAR2 and OAR3. A tri-colour FISH using chromosome paintings and BAC probes has validated this arrangement. A further FISH analysis has been carried out to analyse the telomeres, which showed a normal structure. Nucleolus organiser-bearing chromosomes were identified as pairs OAR1p(CHI3), OAR2q(CHI2), OAR3q(CHI5), OAR4(CHI4) and OAR25(CHI28), and nuclear associations were found. Sex chromosomes were correctly arranged. The odd number of the karyotype might be responsible for a reduced fertility as consequence of the incorrect chromosomal pairing and/or segregation during the meiosis

The NALP3 inflammasome is involved in the innate immune response to amyloid-beta

The fibrillar peptide amyloid-beta (A beta) has a chief function in the pathogenesis of Alzheimer\u27s disease. Interleukin 1 beta (IL-1 beta) is a key cytokine in the inflammatory response to A beta. Insoluble materials such as crystals activate the inflammasome formed by the cytoplasmic receptor NALP3, which results in the release of IL-1 beta. Here we identify the NALP3 inflammasome as a sensor of A beta in a process involving the phagocytosis of A beta and subsequent lysosomal damage and release of cathepsin B. Furthermore, the IL-1 beta pathway was essential for the microglial synthesis of proinflammatory and neurotoxic factors, and the inflammasome, caspase-1 and IL-1 beta were critical for the recruitment of microglia to exogenous A beta in the brain. Our findings suggest that activation of the NALP3 inflammasome is important for inflammation and tissue damage in Alzheimer\u27s disease