Score: 2.00 | Title: A rice homeobox gene , OSH1 , is expressed before organ differentiation in a specific region during early embryogenesis .
| Author: Sato Y Hong SK Tagiri A Kitano H Yamamoto N Nagato Y Matsuoka M | Journal: Proc . Natl . Acad . Sci . USA Citation: V : 93 ( 15 ) P : 8117-22 Year: 1996 Type: ARTICLE | Literature: oryza Field: abstract Doc ID: pub8755613 Accession (PMID): 8755613 | Abstract: Homeobox genes encode a large family of homeodomain proteins that play a key role in the pattern formation of animal embryos .
By analogy , homeobox genes in plants are thought to mediate important processes in their embryogenesis , but there is very little evidence to support this notion .
Here we described the temporal and spatial expression patterns of a rice homeobox gene , OSH1 , during rice embryogenesis .
In situ hybridization analysis revealed that in the wild-type embryo , OSH1 was first expressed at the globular stage , much earlier than organogenesis started , in a ventral region where shoot apical meristem and epiblast would later develop .
This localized expression of OSH1 indicates that the cellular differentiation has already occurred at this stage .
At later stages after organogenesis had initiated , OSH1 expression was observed in shoot apical meristem [ except in the L1 ( tunica ) layer ] , epiblast , radicle , and their intervening it issues in descending strength of expression level with embryonic maturation .
We also performed in situ hybridization analysis with a rice organless embryo mutant , orl1 , that develops no embryonic organs .
In the orl1 embryo , the expression pattern of OSH1 was the same as that in the wild-type embryo in spite of the lack of embryonic organs .
This shows that OSH1 is not directly associated with organ differentiation , but may be related to a regulatory process before or independent of the organ determination .
The results described here strongly suggest that , like animal homeobox genes , OSH1 plays an important role in regionalization of cell identity during early embryogenesis . | Matching Sentences: [ Sen. 7, subscore: 1.00 ]: We also performed in situ hybridization analysis with a rice organless embryo mutant , orl1 , that develops no embryonic organs . [ Sen. 8, subscore: 1.00 ]: In the orl1 embryo , the expression pattern of OSH1 was the same as that in the wild-type embryo in spite of the lack of embryonic organs .
| Supplemental links/files: reference in endnote online text related articles pubmed citation | |