Data from: The structure and allelic diversity of the self-incompatibility locus (S-locus) in diploid potatoes inferred from genome sequences and transcriptome data from styles and pollen

Gametophytic Self-Incompatibility is a reproductive strategy to prevent
inbreeding and promote outcrossing, and it is controlled by the
self-incompatibility locus (S-locus). Studies to understand molecular and
evolutionary aspects of the SI system in the Solanaceae have been
conducted using several genera, including Petunia, Nicotiana, and Solanum.
S-RNases are pistil determinants of gametophytic SI, and multiple S-RNase
alleles have been identified in a few potato species. SLFs, the pollen
determinants of SI, are linked to S-RNases on chromosome 1. The S-RNase
and SLFs present on each chromatid determine an individual’s
self-compatible (SC) or self-incompatible (SI) haplotypes. We used
long-read genome sequencing and RNA sequencing from styles and pollen to
assess the diversity and composition of elements within the S-locus. RNA
for RNA-seq was collected from stylar tissue and germinated pollen. For
three genotypes, PacBio Iso-Sequencing was used to confirm the presence of
alternative transcripts for the S-RNase gene. The combined datasets
enabled us to localize both the male (pollen) and female (stylar)
components of the S-locus. Sequences of the identified S-RNases and SLFs
were used to evaluate their phylogenies along with other Solanaceae
sequences for the same genes obtained from databases. Our analysis showed
that SLF sequences are expressed in pollen but not in styles, vary in
number between individuals, and are distributed across a 9-17 Mb region
flanking one S-RNase gene. Preferential associations within haplotigs of
specific S-RNase types and SLF types were not observed. Extensive sequence
diversity was observed for S-RNases and SLFs, and phylogenetic analysis
indicates that diversification of both genes predates the divergence
between tomatoes and potatoes.