Figure 2: Physical map of the IgH gene locus in two crocodilian species.
From: Extensive diversification of IgH subclass-encoding genes and IgM subclass switching in crocodilians

(a) Physical map of the IgH gene locus in the Siamese crocodile. (b) Physical map of the IgH gene locus in the Chinese alligator. A detailed structure for each gene is also shown under or above the backbone map with the exons indicated by Arabic numerals. All of the α genes in the locus were found to be inverted. ‘ψ’ is used to denote pseudo genes or pseudo exons. M: membrane region-encoding exon.