title: Initial characterization of a protochordate histocompatibility locus.
abstract: The colonial protochordate, Botryllus schlosseri, undergoes a natural transplantation reaction which is controlled by a single, highly polymorphic locus called the Fu/HC. We are using map-based cloning to identify Fu/HC gene(s), and have currently delineated their location to an approximately 1-cM region of the B. schlosseri genome. The Fu/HC physical map currently consists of 85 sequence-tagged sites mapped on a minimum tiling path of 800 kb which consists of five contigs, with four gaps remaining to be crossed, and is estimated to be 75% completed. Approximately half this region has been sequenced throughout the locus, allowing the first analysis of a metazoan histocompatibility locus outside of vertebrates. This has resulted in the identification of 18 predicted genes, a number of which have been found to be expressed. Several of these genes are well conserved among the chordates; however, none of the predicted or expressed genes are linked within the genome of any organism in the databases. In addition, the Fu/HC is one of the most polymorphic loci ever described, and physical mapping has revealed that the locus is quite dynamic, and includes features such as hotspots of recombination.
authors.affiliation: Hopkins Marine Station, Pacific Grove, CA 93950, USA. tdet@stanford.edu
authors.forename: Anthony W
authors.initials: AW
authors.lastname: De Tomaso
authors.forename: Irving L
authors.initials: IL
authors.lastname: Weissman
mesh_terms: D000818:Animals; D006649:Histocompatibility Antigens / Q000235:genetics*; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping; D014561:Urochordata / Q000235:genetics*
chemical_list: D006649:Histocompatibility Antigens