Weefuen Wang | PubMed Health

PubMed2003

15000 unique zebrafish EST clusters and their future use in microarray for profiling gene expression patterns during embryogenesis.

A total of 15590 unique zebrafish EST clusters from two cDNA libraries have been identified. Most significantly, only 22% (3437) of the 15590 unique clusters matched 2805 (of 15200) clusters in the Danio rerio UniGene database, indicating that our EST set is complementary to the existing ESTs in the public database and will be invaluable in assisting the annotation of genes based on the upcoming zebrafish genome sequence. Blast search showed that 7824 of our unique clusters matched 6710 known or predicted proteins in the nonredundant database. A cDNA microarray representing approximately 3100 unique zebrafish cDNA clusters has been generated and used to profile the gene expression patterns across six different embryonic stages (cleavage, blastula, gastrula, segmentation, pharyngula, and hatching). Analysis of expression data using K-means clustering revealed that genes coding for muscle-specific proteins displayed similar expression patterns, confirming that the coordinate gene expression is important for myogenesis. Our results demonstrate that the combination of microarray technology with the zebrafish model system can provide useful information on how genes are coordinated in a genetic network to control zebrafish embryogenesis and can help to identify novel genes that are important for organogenesis.

Animals↗

PubMed2002

Gibberellin regulates Arabidopsis seed germination via RGL2, a GAI/RGA-like gene whose expression is up-regulated following imbibition.

The germination of Arabidopsis seeds is promoted by gibberellin (GA). Arabidopsis GAI, and RGA are genes encoding key GA signal-transduction components (GAI and RGA) that mediate GA regulation of stem elongation. The Arabidopsis genome contains two further genes, RGL1 and RGL2, that encode proteins (RGL1 and RGL2) that are closely related to GAI and RGA. Here, we show that RGL2 regulates seed germination in response to GA, and that RGL1, GAI, and RGA do not. In addition, we show that RGL2 transcript levels rise rapidly following seed imbibition, and then decline rapidly as germination proceeds. In situ GUS staining revealed that RGL2 expression in imbibed seeds is restricted to elongating regions of pre-emergent and recently emerged radicles. These observations indicate that RGL2 is a negative regulator of GA responses that acts specifically to control seed germination rather than stem elongation. Furthermore, as RGL2 expression is imbibition inducible, RGL2 may function as an integrator of environmental and endogenous cues to control seed germination.

Amino Acid Sequence↗