Identification of genes expressed in the Arabidopsis female gametophyte
Article first published online: 8 JUN 2007
The Plant Journal
Volume 51, Issue 2, pages 281–292, July 2007
How to Cite
Steffen, J. G., Kang, I.-H., Macfarlane, J. and Drews, G. N. (2007), Identification of genes expressed in the Arabidopsis female gametophyte. The Plant Journal, 51: 281–292. doi: 10.1111/j.1365-313X.2007.03137.x
- Issue published online: 8 JUN 2007
- Article first published online: 8 JUN 2007
- Received 08 December 2006; revised 08 March 2007; accepted 22 March 2007.
- female gametophyte;
- embryo sac;
- plant reproduction;
The angiosperm female gametophyte typically consists of one egg cell, two synergid cells, one central cell, and three antipodal cells. Each of these four cell types has unique structural features and performs unique functions that are essential for the reproductive process. The gene regulatory networks conferring these four phenotypic states are largely uncharacterized. As a first step towards dissecting the gene regulatory networks of the female gametophyte, we have identified a large collection of genes expressed in specific cells of the Arabidopsis thaliana female gametophyte. We identified these genes using a differential expression screen based on reduced expression in determinant infertile1 (dif1) ovules, which lack female gametophytes. We hybridized ovule RNA probes with Affymetrix ATH1 genome arrays and validated the identified genes using real-time RT-PCR. These assays identified 71 genes exhibiting reduced expression in dif1 ovules. We further validated 45 of these genes using promoter::GFP fusions and 43 were expressed in the female gametophyte. In the context of the ovule, 11 genes were expressed exclusively in the antipodal cells, 11 genes were expressed exclusively or predominantly in the central cell, 17 genes were expressed exclusively or predominantly in the synergid cells, one gene was expressed exclusively in the egg cell, and three genes were expressed strongly in multiple cells of the female gametophyte. These genes provide insights into the molecular processes functioning in the female gametophyte and can be used as starting points to dissect the gene regulatory networks functioning during differentiation of the four female gametophyte cell types.