@article{stinchcombe_weinig_ungerer_olsen_mays_halldorsdottir_purugganan_schmitt_2004, title={A latitudinal cline in flowering time in Arabidopsis thaliana modulated by the flowering time gene FRIGIDA}, volume={101}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.0306401101}, abstractNote={A latitudinal cline in flowering time in accessions of Arabidopsis thaliana has been widely predicted because the environmental cues that promote flowering vary systematically with latitude, but evidence for such clines has been lacking. Here, we report evidence of a significant latitudinal cline in flowering time among 70 Northern European and Mediterranean ecotypes when grown under ecologically realistic conditions in a common garden environment. The detected cline, however, is found only in ecotypes with alleles of the flowering time gene FRIGIDA ( FRI ) that lack major deletions that would disrupt protein function, whereas there is no relationship between flowering time and latitude of origin among accessions with FRI alleles containing such deletions. Analysis of climatological data suggests that late flowering in accessions with putatively functional FRI was associated with reduced January precipitation at the site of origin, consistent with previous reports of a positive genetic correlation between water use efficiency and flowering time in Arabidopsis , and the pleiotropic effects of FRI of increasing water use efficiency. In accessions collected from Southern latitudes, we detected that putatively functional FRI alleles were associated with accelerated flowering relative to accessions with nonfunctional FRI under the winter conditions of our experiment. These results suggest that the ecological function of the vernalization requirement conferred by FRI differs across latitudes. More generally, our results indicate that by combining ecological and molecular genetic data, it is possible to understand the forces acting on life history transitions at the level of specific loci.}, number={13}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Stinchcombe, JR and Weinig, C and Ungerer, M and Olsen, KM and Mays, C and Halldorsdottir, SS and Purugganan, MD and Schmitt, J}, year={2004}, month={Mar}, pages={4712–4717} }
 @article{olsen_halldorsdottir_stinchcombe_weinig_schmitt_purugganan_2004, title={Linkage disequilibrium mapping of Arabidopsis CRY2 flowering time alleles}, volume={167}, ISSN={["1943-2631"]}, DOI={10.1534/genetics.103.024950}, abstractNote={Abstract The selfing plant Arabidopsis thaliana has been proposed to be well suited for linkage disequilibrium (LD) mapping as a means of identifying genes underlying natural trait variation. Here we apply LD mapping to examine haplotype variation in the genomic region of the photoperiod receptor CRYPTOCHROME2 and associated flowering time variation. CRY2 DNA sequences reveal strong LD and the existence of two highly differentiated haplogroups (A and B) across the gene; in addition, a haplotype possessing a radical glutamine-to-serine replacement (AS) occurs within the more common haplogroup. Growth chamber and field experiments using an unstratified population of 95 ecotypes indicate that under short-day photoperiod, the AS and B haplogroups are both highly significantly associated with early flowering. Data from six genes flanking CRY2 indicate that these haplogroups are limited to an ∼65-kb genomic region around CRY2. Whereas the B haplogroup cannot be delimited to <16 kb around CRY2, the AS haplogroup is characterized almost exclusively by the nucleotide polymorphisms directly associated with the serine replacement in CRY2; this finding strongly suggests that the serine substitution is directly responsible for the AS early flowering phenotype. This study demonstrates the utility of LD mapping for elucidating the genetic basis of natural, ecologically relevant variation in Arabidopsis.}, number={3}, journal={GENETICS}, author={Olsen, KM and Halldorsdottir, SS and Stinchcombe, JR and Weinig, C and Schmitt, J and Purugganan, MD}, year={2004}, month={Jul}, pages={1361–1369} }
 @article{ungerer_halldorsdottir_purugganan_mackay_2003, title={Genotype-environment interactions at quantitative trait loci affecting inflorescence development in Arabidopsis thaliana}, volume={165}, number={1}, journal={Genetics}, author={Ungerer, M. C. and Halldorsdottir, S. S. and Purugganan, M. D. and Mackay, T. F. C.}, year={2003}, month={Sep}, pages={353–365} }
 @article{weinig_ungerer_dorn_kane_toyonaga_halldorsdottir_mackay_purugganan_schmitt_2002, title={Novel loci control variation in reproductive timing in Arabidopsis thaliana in natural environments}, volume={162}, number={4}, journal={Genetics}, author={Weinig, C. and Ungerer, M. C. and Dorn, L. A. and Kane, N. C. and Toyonaga, Y. and Halldorsdottir, S. S. and Mackay, T. F. C. and Purugganan, M. D. and Schmitt, J.}, year={2002}, month={Dec}, pages={1875–1884} }
 @article{ungerer_halldorsdottir_modliszewski_mackay_purugganan_2002, title={Quantitative trait loci for inflorescence development in Arabidopsis thaliana}, volume={160}, number={3}, journal={Genetics}, author={Ungerer, M. C. and Halldorsdottir, S. S. and Modliszewski, J. L. and Mackay, T. F. C. and Purugganan, M. D.}, year={2002}, month={Mar}, pages={1133–1151} }