TY  - JOUR
A1  - Potente, Giacomo
A1  - Léveillé-Bourret, Étienne
A1  - Yousefi, Narjes
A1  - Choudhury, Rimjhim Roy
A1  - Keller, Barbara
A1  - Diop, Seydina Issa
A1  - Duijsings, Daniël
A1  - Pirovano, Walter
A1  - Lenhard, Michael
A1  - Szövényi, Péter
A1  - Conti, Elena
T1  - Comparative genomics elucidates the origin of a supergene controlling floral heteromorphism
JF  - Molecular biology and evolution : MBE
N2  - Supergenes are nonrecombining genomic regions ensuring the coinheritance of multiple, coadapted genes. Despite the importance of supergenes in adaptation, little is known on how they originate. A classic example of supergene is the S locus controlling heterostyly, a floral heteromorphism occurring in 28 angiosperm families. In Primula, heterostyly is characterized by the cooccurrence of two complementary, self-incompatible floral morphs and is controlled by five genes clustered in the hemizygous, ca. 300-kb S locus. Here, we present the first chromosome-scale genome assembly of any heterostylous species, that of Primula veris (cowslip). By leveraging the high contiguity of the P. veris assembly and comparative genomic analyses, we demonstrated that the S-locus evolved via multiple, asynchronous gene duplications and independent gene translocations. Furthermore, we discovered a new whole-genome duplication in Ericales that is specific to the Primula lineage. We also propose a mechanism for the origin of S-locus hemizygosity via nonhomologous recombination involving the newly discovered two pairs of CFB genes flanking the S locus. Finally, we detected only weak signatures of degeneration in the S locus, as predicted for hemizygous supergenes. The present study provides a useful resource for future research addressing key questions on the evolution of supergenes in general and the S locus in particular: How do supergenes arise? What is the role of genome architecture in the evolution of complex adaptations? Is the molecular architecture of heterostyly supergenes across angiosperms similar to that of Primula?
KW  - genome architecture
KW  - supergene
KW  - heterostyly
KW  - evolutionary genomics
KW  - chromosome-scale genome assembly
KW  - primula
Y1  - 2022
U6  - https://doi.org/10.1093/molbev/msac035
SN  - 0737-4038
SN  - 1537-1719
VL  - 39
IS  - 2
PB  - Oxford Univ. Press
CY  - Oxford
ER  -