A Gene Encoding a DUF247 Domain Protein Cosegregates with the S Self-Incompatibility Locus in Perennial Ryegrass

Mol Biol Evol. 2016 Apr;33(4):870-84. doi: 10.1093/molbev/msv335. Epub 2015 Dec 10.


The grass family (Poaceae), the fourth largest family of flowering plants, encompasses the most economically important cereal, forage, and energy crops, and exhibits a unique gametophytic self-incompatibility (SI) mechanism that is controlled by at least two multiallelic and independent loci, S and Z. Despite intense research efforts over the last six decades, the genes underlying S and Z remain uncharacterized. Here, we report a fine-mapping approach to identify the male component of the S-locus in perennial ryegrass (Lolium perenne L.) and provide multiple evidence that a domain of unknown function 247 (DUF247) gene is involved in its determination. Using a total of 10,177 individuals from seven different mapping populations segregating for S, we narrowed the S-locus to a genomic region containing eight genes, the closest recombinant marker mapping at a distance of 0.016 cM. Of the eight genes cosegregating with the S-locus, a highly polymorphic gene encoding for a protein containing a DUF247 was fully predictive of known S-locus genotypes at the amino acid level in the seven mapping populations. Strikingly, this gene showed a frameshift mutation in self-compatible darnel (Lolium temulentum L.), whereas all of the self-incompatible species of the Festuca-Lolium complex were predicted to encode functional proteins. Our results represent a major step forward toward understanding the gametophytic SI system in one of the most important plant families and will enable the identification of additional components interacting with the S-locus.

Keywords: RNA sequencing (RNAseq); S-locus; domain of unknown function (DUF) 247; fine-mapping; perennial ryegrass (Lolium perenne L.); self-incompatibility (SI).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Mapping*
  • Genetic Linkage
  • Genotype
  • High-Throughput Nucleotide Sequencing
  • Plant Proteins / genetics*
  • Plant Weeds / genetics*
  • Protein Kinases / genetics
  • Self-Incompatibility in Flowering Plants / genetics*


  • Plant Proteins
  • Protein Kinases
  • S-receptor kinase