2026-07-23 森林総合研究所,新潟大学,基礎生物学研究所,岡山大学
図1 正常なスギとMS2タイプの無花粉スギの雄花の比較
＜関連情報＞
- https://www.ffpri.go.jp/press/2026/20260723-01/index.html
- https://link.springer.com/article/10.1186/s12864-026-12907-4
スギ（Cryptomeria japonica D. Don）における連鎖地図作成とトランスクリプトームデータによる雄性不妊2（MS2 ）候補遺伝子の位置同定 Positional identification of a candidate gene for MALE STERILITY 2 (MS2) by linkage mapping and transcriptomic data in Cryptomeria japonica D. Don
Saneyoshi Ueno,Yoichi Hasegawa,Tokuko Ujino-Ihara,Momi Tsuruta,Hiroyuki Kakui,Junji Iwai,Satoko Hirayama,Katsushi Yamaguchi,Shuji Shigenobu,Takeshi Fujino,Yutaka Suzuki,Masahiro Kasahara & Yoshinari Moriguchi
BMC Genomics Published:19 May 2026
DOI:https://doi.org/10.1186/s12864-026-12907-4
Abstract
Background
Japanese cedar (Cryptomeria japonica D. Don) is a major plantation species in Japan, but its abundant pollen production is a primary cause of seasonal allergic rhinitis (pollinosis). To mitigate this public health issue, the use of male-sterile cultivars has been promoted. Five types of recessive male-sterile mutations (ms1–ms5) have been identified, and the causal genes and mutations for MS1 and MS4 have been elucidated. However, the gene responsible for MS2-type male sterility remains unknown.
Results
We aimed to identify the candidate gene responsible for MS2-type male sterility using a map-based cloning strategy. High-resolution linkage mapping localized the MS2 locus to a 1.56 cM interval on linkage group 5, corresponding to an 8.64 Mb region of the reference genome. Ninety-one genes in this region were subjected to functional annotation, gene expression analysis, and mutation screening. Among these, a single gene, SUGI_0493010, encoding a GDSL-type esterase/lipase protein (GELP), fulfilled all three criteria: it showed homology to pollen development genes in Arabidopsis thaliana, was specifically expressed in male strobili, and carried a deleterious amino acid substitution (S40F) within the predicted catalytic domain in ms2 mutant. The same mutation was also detected in a heterozygous individual (Ms2/ms2) from a separate breeding population, whose genotype was confirmed through progeny testing. Structural annotation revealed that the affected serine residue lies within the conserved GDSL motif, suggesting a functional disruption of enzymatic activity.
Conclusions
Our results strongly suggest that SUGI_0493010 (GELP) is the candidate gene for MS2-type male sterility in C. japonica. This finding enhances our understanding of male sterility mechanisms in conifers and provides a valuable genetic resource for breeding pollen-free trees. The study also demonstrates the effectiveness of combining genetic mapping with transcriptomic and mutational data in forest tree genomics.
