Quantitative trait loci and global expression patterns offer insight into phenotypic plasticity

DNA microarrays;Climatic changes;Gene mapping;Arabidopsis thaliana;Phenotypic plasticity

Rubin, Matthew J.Dorn, Lisa ;

University of Wisconsin

关键词: DNA microarrays;    Climatic changes;    Gene mapping;    Arabidopsis thaliana;    Phenotypic plasticity;   

Others  :  https://minds.wisconsin.edu/bitstream/handle/1793/56882/Rubin%2c_Matthew.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: University of Wisconsin

【 摘 要 】

Phenotypic plasticity, i.e. changes in phenotype with environment, may allow organismsto produce optimal phenotypes in all environments (adaptive plasticity). There isconsiderable discussion about the genetic mechanisms for phenotypic plasticity.However, there is some agreement that changes in gene expression must be involved. Inorder to examine how natural selection has acted on phenotypic plasticity on the traitbolting time trait (transition to reproduction) and gene expression patterns in pastpopulations, a set of Recombinant Inbred Lines (RILs) of Arabidopsis thaliana wereused. We tested the effect of cold-treating seeds (stratification) on bolting time inArabidopsis thaliana. Cold stratification of seeds may be one environmental factorcontributing to variation in spring versus fall germination in A. thaliana populations.Variation in both the direction and degree of plasticity was observed in a set of 120 RILsscreened; genotypic selection analysis showed that past selection had favored boltingearlier in both environments. Three RILs that displayed extreme plasticities for boltingtime in opposing directions across cold treatments were identified and global geneexpression patterns were measured in a microarray experiment. A total of 294 genes wereidentified as being differentially expressed across cold treatments for the three extremeRILs (Fold change of >2; p-value<0.05). In addition, Quantitative Trait Loci (QTL) forbolting time were mapped in the complete set of RILs. Five QTL were mapped in thecold environment and three QTL were mapped in the no-cold environment explaining40% and 30% of the observed phenotypic variation, respectively. QTL underlyingvariation in bolting time were screened for differentially expressed genes from themicroarray study to identify candidate genes. Ninety-three of the identified genes colocalizedto bolting time QTL, with kinesis and transferases being overrepresented in theexpressed QTLs. Few studies have combined microarray and QTL data, and this studywill offer insight into the genetic mechanism of phenotypic plasticity.