Zoo-FISH analysis of dog chromosome 5: identification of conserved syntenywith human and cat chromosomes

Conserved segments of synteny between the human genome and chromosome 5 (CF A 5) of the domestic dog (Canis familiaris) have been identified by recipro cal chromosome painting analysis. A CFA 5 paint probe was applied to human metaphase spreads, revealing distinct hybridisation sites on human (HSA) ch romosomes 1, 11, 16, and 17. Paint probes for these human chromosomes were then hybridised to dog metaphase spreads, identifying the regions of CFA 5 with which homology is shared with the corresponding human chromosome. Appl ication of the CFA 5 paint probe to metaphase spreads of the domestic cat ( Felis catus, FCA) demonstrated hybridisation to cat chromosomes C1, D1, E1, and E2. Dog PCR primers for type 1 markers known to lie in the correspondi ng regions of HSA 11, 16, and 17 were used to isolate dog BAC clones repres enting four genes. Fluorescence in situ hybridisation analysis confirmed th eir localisation to CFA 5 and suggested that two of the conserved segments lie in opposing orientations on CFA 5, compared to the human chromosome con cerned. A third segment appears to lie in the same orientation on both huma n and dog chromosomes. No suitable gene markers were available for analysis of the fourth segment. The significance of these findings is discussed wit h reference to current and future dog genome mapping efforts. Copyright (C) 1999 S. Karger AG, Basel.