Dr Dorothea Heimeier (Harrison)

The major histocompatibility complex (MHC) is a highly polymorphic gene family that is crucial in immunity against pathogens, and its diversity can be effectively used as a fitness marker for populations. Despite this important role, MHC remains poorly characterised in non-model species (e.g., cetaceans) as high gene copy number variation, especially in the fast-evolving class I region, makes analyses of genomic sequences difficult. To date, only sections of class I and IIa exon 2 genes have been used to assess functional diversity in cetacean populations. By utilising numerous cetacean genomes that have been published to date, we have developed a next generation sequencing panel that simultaneously sequences the complete exon 2 of five MHC genes from class IIa and class I. We validated this panel in 19 cetacean species and described 354 alleles for class I and IIa. Furthermore, we investigated MHC diversity using the panel in 25 humpback whales, including four paternity trios . This revealed potential classical and non-classical class I genes and determined copy number variable class I haplotypes in humpback whales, likely a common phenomenon across Cetacea. These MHC alleles will form the basis for a cetacean branch of the Immuno-Polymorphism Database (IPD-MHC), a curated resource intended to aid in the systematic compilation of MHC alleles across several different animal species, to support conservation initiatives.