Teleostei SERC2a/b, gene synteny: Paralogs share a conserved gene synteny, except for gene SERC2a of Danio (ENSDARG00000056532, ENSDARP00000026726). Analysis of the gene regions of the conserved neighboring genes from Takifugu and Gasterosteus: for 2 of the 4 analyzed genes, Danio possesses an additional gene copy in comparison to the other 2 species. For Danio, the unique 3’ neighborhood of SERC2a includes genes, which are located on the same chromosomes than the SERC genes. For Danio, the unique 3’ neighborhood of SERC2a includes the gene frt55, which has about 30-40 lineage-specific paralogs. Conclusion: The gene relationship between the SERC2a gene of Danio and SERC2a of the other 2 teleostei remains dubious. The gene Danio SERC2a was therefore removed from the reference tree.