Research record26 May 2026Journal article
An X-linked sex determination mechanism in cannabis and hop
Sarah B. Carey, Philip C. Bentz, John T. Lovell, Laramie M. Akozbek, Zachary A. Myers, Walid Korani, Joshua S. Havill, Lillian Padgitt-Cobb, Ryan C. Lynch, Nicholas Allsing, Jack Mangels, Zachary Stansell, George M. Stack, Tyler Gordon, Austin Osmanski, Katherine A. Easterling, Leonardo R. Orozco, Zach E. Marcus, Haley Hale, Hannah McCoy, Zachary Meharg, Jane Grimwood, Lawrence B. Smart, Daniela Vergara, Rafael F. Guerrero, Nolan C. Kane, Rich Fletcher, John K. McKay, Todd P. Michael, Gary J. Muehlbauer, Josh Clevenger, Alex Harkess
Nature Communications · 2026
Abstract
Sex chromosomes in cannabis and hop were identified a century ago because of their obvious visible differences in size (heteromorphy). However, we know little about the genes they contain that control the development of the inflorescences. Here we assembled genomes, with phased sex chromosomes, for hop and cannabis. The XY chromosomes share an origin prior to the divergence between the genera around 36 MYA. Due to the inheritance patterns of the XYs, the male-specific region of the Y is highly-degenerated, with substantial gene loss, while the X shows faster rates of molecular evolution. Consistent with the hypothesis that these species lack an active-Y system, no clear sex-determining genes reside on the Y. Instead, an X-linked homolog of aminocyclopropane-1-carboxylate synthase (ACS), that is involved in the ethylene biosynthesis pathway, determines the fate of the female inflorescence. Beyond sex determination, the sex chromosomes contribute to the sexual dimorphism in ecology and physiology and have played a role in the domestication and breeding of these species.
The paper's abstract, reproduced as published.
Record created 8 August 2026 · maintained by landrace.wiki editors ·
page history
Published26 May 2026
TypeJournal article
VenueNature Communications
Year2026
2026-05-26
2026-08-08
An X-linked sex determination mechanism in cannabis and hop
Journal article
Genetics
Sarah B. Carey, Philip C. Bentz, John T. Lovell, Laramie M. Akozbek, Zachary A. Myers, Walid Korani, Joshua S. Havill, Lillian Padgitt-Cobb, Ryan C. Lynch, Nicholas Allsing, Jack Mangels, Zachary Stansell, George M. Stack, Tyler Gordon, Austin Osmanski, Katherine A. Easterling, Leonardo R. Orozco, Zach E. Marcus, Haley Hale, Hannah McCoy, Zachary Meharg, Jane Grimwood, Lawrence B. Smart, Daniela Vergara, Rafael F. Guerrero, Nolan C. Kane, Rich Fletcher, John K. McKay, Todd P. Michael, Gary J. Muehlbauer, Josh Clevenger, Alex Harkess
Nature Communications
2026
10.1038/s41467-026-73233-7
https://doi.org/10.1038/s41467-026-73233-7
Presents phased sex-chromosome assemblies for Cannabis sativa and Humulus lupulus and dates the origin of their shared XY pair to roughly 36 million years ago, before the two genera diverged. The Y chromosome is heavily degenerated and carries no clear sex-determining gene. The authors instead attribute female inflorescence fate to an X-linked homologue of aminocyclopropane-1-carboxylate synthase, placing the ethylene pathway at the centre of the mechanism. The finding bears directly on the treatment of sex determination and dioecy in Cannabis.
Sex chromosomes in cannabis and hop were identified a century ago because of their obvious visible differences in size (heteromorphy). However, we know little about the genes they contain that control the development of the inflorescences. Here we assembled genomes, with phased sex chromosomes, for hop and cannabis. The XY chromosomes share an origin prior to the divergence between the genera around 36 MYA. Due to the inheritance patterns of the XYs, the male-specific region of the Y is highly-degenerated, with substantial gene loss, while the X shows faster rates of molecular evolution. Consistent with the hypothesis that these species lack an active-Y system, no clear sex-determining genes reside on the Y. Instead, an X-linked homolog of aminocyclopropane-1-carboxylate synthase (ACS), that is involved in the ethylene biosynthesis pathway, determines the fate of the female inflorescence. Beyond sex determination, the sex chromosomes contribute to the sexual dimorphism in ecology and physiology and have played a role in the domestication and breeding of these species.
