A distorter-restorer system drives quantitative reproductive isolation in rice.
Zhang Y, Yang Y, Shi C, Pu Q, Zhou J
Summary
8.0/10Scientists found a genetic 'lock' that prevents different rice species from breeding together. Using CRISPR gene editing, they discovered how to remove this lock—enabling creation of new rice varieties with desirable traits from both species.
Key Findings
A genetic system called S44 contains four linked components (RID, RIR, RIA, RIS) that together control hybrid sterility and prevent cross-breeding between rice species
The RID element eliminates pollen from one rice species while RIR protects gametes of another species, creating a genetic bias toward the wild rice species
CRISPR-engineered knockout of the RID gene can universally overcome reproductive barriers in rice, enabling revolutionary cross-species breeding for crop improvement
Original Abstract
Hybrid sterility and segregation distortion are the major forms of postzygotic reproductive isolation in rice, yet the molecular basis of their quantitative variation remains unclear. Here we identify S44, a natural distorter-restorer system in Oryza longistaminata/Asian cultivated rice hybrids, comprising four tightly linked elements-Reproductive Isolation Distorter (RID), Reproductive Isolation Restorer (RIR), Reproductive Isolation Activator (RIA) and Reproductive Isolation Suppressor (RIS)-which collectively regulate hybrid male sterility and segregation distortion. The distorter RID triggers the elimination of O. sativa cultivar RD23 pollen, whereas the restorer RIR selectively safeguards O. longistaminata gametes, thereby preferentially transmitting its allele into the progeny. RIS and RIA fine-tune segregation distortion. We further demonstrate that the allelic conflicts at the S44 locus drive quantitative reproductive isolation between O. longistaminata and other rice lineages, and CRISPR-engineered RID knockout can universally overcome S44-mediated reproductive barriers in the AA genome, enabling revolutionary cross-species breeding. This distorter-restorer system provides a unique genetic module for deciphering speciation mechanisms and advancing crop breeding strategies.
Species Mentioned
Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species Oryza sativa —or, much less commonly, Oryza glaberrima. Asian rice was domesticated in China some 13,500 to 8,200 y...
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