Fig. 4. Identification of ESD1. (A) Map-based cloning of ESD1. The genetic interval, molecular markers and BAC clones in the ESD1 region are shown. The number of recombinant events between molecular markers is given in parentheses. The centromere is located between the T15D2 and T25F15 markers (http://www.arabidopsis.org/info/agicomplete.jsp). GAP indicates the existence of genomic regions of unknown size, where it was not possible to get overlapping BAC clones. Gray bars correspond to the deleted region in each esd1 allele. The ESD1 locus was delimited to a deleted overlapping genomic region between the 5F21A14 and 1T14A11 molecular markers. Mb, megabases. (B) Complementation of the esd1 mutant. Col, esd1-3 and TN 18.1, a transgenic esd1-3 plant containing the genomic region harbouring open reading frames At3g33520 y At3g33530, shown at the time of bolting initiation. (C) Flowering phenotype of esd1-10, a T-DNA insertion allele. Left, Col plant; right, a homozygous plant for the T-DNA insertion within the At3g33520 gene (Wisc Ds-Lox 289 line), showing an early flowering phenotype. RT-PCR analyses of the expression of At3g33520 in esd1-10 show no expression of this gene in the T-DNA mutant, indicating that it is a loss-of-function allele.