A masculinizing supergene underlies an exaggerated male reproductive morph in a spider

• DOI: 10.1038/s41559-021-01626-6
• Publication Date: 2021-12-23T17:03:07Z
• Authors: Frederik Hendrickx; Zoë De Corte; Gontran Sonet; Steven M. Van Bel...; Stephan Köstlbacher; Carl Vangestel
• Keywords: Male; 0301 basic medicine; 03 medical and health sciences; Genome; Phenotype; Reproduction; Life Science; Animals; Female; Spiders; Chromosomes

AbstractIn many species, individuals can develop into strikingly different morphs, which are determined by a simple Mendelian locus. How selection shapes loci that control complex phenotypic differences remains poorly understood. In the spiderOedothorax gibbosus, males either develop into a ‘hunched’ morph with conspicuous head structures or as a fast developing ‘flat’ morph with a female-like appearance. We show that the hunched-differs from the flat-determining allele by a hunch-specific genomic fragment of approximately 3 megabases. This fragment comprises dozens of genes that duplicated from genes found at different chromosomes. All functional duplicates, includingdoublesex- a key sexual differentiation regulatory gene, show male-specific expression, which illustrates their combined role as a masculinizing supergene. Our findings demonstrate how extensive indel polymorphisms and duplications of regulatory genes may contribute to the evolution of co-adapted gene clusters, sex-limited reproductive morphs, and the enigmatic evolution of exaggerated sexual traits in general.