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Plant Sex Chromosomes.
1Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom;
Annual Review of Plant Biology
|December 15, 2015
Summary
Many plant species have genetic sex determination, with unique sex-linked regions on their chromosomes. These regions, similar to animal sex chromosomes, show genetic degeneration and are valuable for studying evolutionary timescales.
Area of Science:
- Plant genetics
- Evolutionary biology
- Sex determination
Background:
- Dioecious species, where individuals are male or female, are common across diverse plant groups.
- Genetic sex determination is prevalent, with some species exhibiting visible sex chromosomes, while others have smaller, cytologically undetectable sex-linked regions.
- These plant sex-linked regions share similarities with animal sex chromosomes, including repetitive sequence accumulation and genetic degeneration.
Purpose of the Study:
- To investigate the characteristics of sex-linked regions in plants.
- To compare plant sex determination mechanisms with those in animals.
- To understand the evolutionary timescale of sex-linked region development in plants.
Main Methods:
- Analysis of genetic sex determination in various plant species.
- Molecular genetic studies to identify sex-linked markers.
- Cytological examination of sex chromosomes.
- Estimation of recombination cessation times in sex-linked regions.
Main Results:
- Plant sex-linked regions, even small or cytologically undetectable ones, exhibit genetic degeneration and repetitive sequence accumulation, mirroring animal sex chromosomes.
- Many plant sex-linked regions are evolutionarily young.
- Recombination cessation timing provides insights into the age and evolution of these regions.
Conclusions:
- Plant sex determination systems are diverse and evolve through mechanisms similar to those in animals.
- The study of plant sex-linked regions offers a valuable model for understanding the evolution of sex chromosomes and genetic degeneration over time.
- Plants provide a unique opportunity to study the timescale of sex-linked region evolution due to the presence of many young systems.
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