Characterization of class IIA andB genes in a gynogenetic carp clone
- Cite this article as:
- van Erp, S.H.M., Egberts, E. & Stet, R.J.M. Immunogenetics (1996) 44: 192. doi:10.1007/BF02602585
A prerequisite for carrying out functional studies on major histocompatibility complex (Mhc) molecules of fish is the availability of genetically well-defined homozygous strains. Previously we have applied gynogenetic reproduction to generate isogenic carp, denoted clone A410. This clone has recently been demonstrated to express a single class I gene,Cyca-UA1*01, and in the present study two class IIB and two class IIA transcripts were obtained. The two class IIB transcript,Cyca-D(CB3)B andCyca-D(CB4)B, as well as the class II A transcripts,Cycaw-D (10A)A andCyca-D(15A)A, appear to be bona fide class II transcripts, based on the presence of conserved protein characteristics of the inferred class II molecules. With the isolation of class IIA sequences, representatives of all major classes ofMhc genes have been identified in the carp. To assess the relationship between the different class II genes, segregation studies, comparison of cDNA and intron 1 sequence data, and phylogenetic analyses were undertaken. These showed that the class IIB transcripts,Cyca-D(CB3)B andCyca-D(CB4)B, are derived from related, closely lined loci. In addition, these studies indicated that the previously describedCyca-DAB*01 andCyca-DAB*02 are also closely linked, but that this linked pair segregates independently from theCyca-D(CB3)B andCyca-D(CB4)B loci. The class IIA transcripts are most likely derived from separate loci and do not represent alleles, as they were found not to segregate in the individuals of the clone which was generated by meiogenetic gynogenesis.