evolution; adaptation; mating system; phenology; Arabidopsis
Yamada Megumi, Shimizu-Inatsugi Rie, Shimizu Kentaro K, Sese Jun (2013), Quantified expression levels of genes in allopolyploid species. IPSJ SIG Technical Reports, in Information Processing Society of Japan
, 28, 1-2.
Tsuchimatsu Takashi, Kaiser Paskal, Yew Chow-Lih, Bachelier Julien B., Shimizu Kentaro K. (2012), Recent Loss of Self-Incompatibility by Degradation of the Male Component in Allotetraploid Arabidopsis kamchatica, in PLoS Genetics
, 8(7), e1002838-e1002838.
de la Chaux Nicole, Tsuchimatsu Takashi, Shimizu Kentaro K, Wagner Andreas (2012), The predominantly selfing plant Arabidopsis thaliana experienced a recent reduction in transposable element abundance compared to its outcrossing relative Arabidopsis lyrata., in Mobile DNA
, 3(1), 2-2.
Kawagoe Tetsuhiro, Shimizu Kentaro K, Kakutani Tetsuji, Kudoh Hiroshi (2011), Coexistence of trichome variation in a natural plant population: a combined study using ecological and candidate gene approaches., in PloS one
, 6(7), 22184-22184.
Shimizu Kentaro K, Kudoh Hiroshi, Kobayashi Masaki J (2011), Plant sexual reproduction during climate change: gene function in natura studied by ecological and evolutionary systems biology., in Annals of botany
, 108(4), 777-87.
A central question in biology is the molecular basis of biodiversity. Rapid advances in genomics provide novel tools for addressing key ecological and evolutionary questions in integrated biological sciences. Still, the study of adaptive molecular variation has been mostly limited to well-defined traits in model species. Since the preceding project, we have used A. thaliana and its relatives to study adaptation and speciation, including the evolution of self-compatibility and speciation by genome duplication. This follow-up proposal will extend two of our recent publications (Tsuchimatsu et al. Nature 464:1342-6, 2010 and Aikawa et al. Proc Natl Acad Sci USA 107:11632-7, 2010). First, we have revealed that the evolution of self-compatibility of A. thaliana occurred by a mutation in the male specificity gene SCR, and supported its recent origin during glacial-interglacial cycles. In this study, we found that floral traits responsible for selfing syndrome, such as the timing of autopollination by the coordinated growth of pistil and stamen, are polymorphic among accessions of A. thaliana. Although floral morphology of selfing species has been a major topic in evolution and ecology, very little is known about the genes responsible for it. In this project, we plan to identify them using genome-wide association studies combined with microarray data. We will conduct functional and evolutionary analysis to test how rapidly floral traits evolved. Second, we have studied a perennial species A. halleri, and found that the expression of the FLC flowering time gene shows one-year cycle, corresponding its perennial phenology. The advantage of A. halleri is that it is a perennial species with established transgenic technique, and we have already constructed transgenic plants in which the FLC expression was reduced by RNAi. In this proposal, we will analyze its phenotype regarding meristem identity and floral reversion. We also conduct functional and evolutionary analysis of vernalization responsive element in the first intron of the FLC gene.This proposal will strengthen the message from our previous research to the society stating that climate changes such as glacial cycles may induce rapid evolution that would be difficult to revert.