 |
|
|
|
 |
 |
 |
| Contact Us | Register |
| SITE SEARCH |
| HOME |
| ONLINE COMMUNITY |
| MEMBERSHIP |
| MEETINGS & EVENTS |
| PUBLICATIONS/RESOURCES |
| CAREERS |
| GOVERNANCE |
| SECTIONS |
| AWARDS & FUNDING |
| EDUCATION & RESEARCH |
| PUBLIC AFFAIRS |
| EDUCATION FOUNDATION |
| ABOUT US |
 
Public Release Date: 29 July 2005 Contact: Nancy Eckardt Trapping Genes That Control Flower Development Scientists at Yale University and Cold Spring Harbor Laboratory employ "gene trapping" to identify many genes involved in the regulation of flower development. This is the first large-scale gene trap study on flower development, and provides extensive information on many genes likely to have critical roles in this essential stage of plant reproduction. This research, conducted with grant support from the National Science Foundation, is an excellent example of how modern molecular biology techniques help to increase our understanding of complex biological processes. Full release. Contacts: Nancy Eckardt Vivian Irish Robert Martienssen
Trapping Genes That Control Flower Development Scientists use molecular "gene trap" to identify dozens of genes involved in the regulation of flower development Identifying genes based on patterns of gene expression in specific organs or at specific stages of development is a useful approach to improving our understanding of complex biological processes. Scientists Vivian Irish at Yale University in Connecticut, Rob Martienssen at Cold Spring Harbor Laboratory in New York, and their colleagues used a strategy known as "gene trapping" to identify numerous genes involved in the regulation of flower development in the model plant Arabidopsis thaliana. The research is reported in a paper by Nakayama et al. in the September issue of The Plant Cell. The gene trap technique involves genetic transformation of Arabidopsis plants with a reporter gene whose activity is visualized in a simple assay, leading to the rapid identification of genes that show specific patterns of expression. In this case, the researchers isolated 80 different gene trap Arabidopsis lines identifying genes that show distinct patterns of expression in flower petals and/or stamens (the pollen-bearing organs). The research is one of the first large-scale gene trap studies in the area of flower development, and provides extensive information on many genes likely to have critical roles in this essential stage of plant reproduction. Genes provide the blueprints for proteins that carry out the functions of living cells. In any particular organ or tissue at any particular stage of development, gene activity may be "on" (expressing the messenger RNA transcripts that lead to production of the corresponding protein) or "off" (no expression). Examining gene expression patterns therefore provides information on gene function. Gene trapping is an alternative to methods such as DNA microarray analysis for the detection of differentially expressed genes, and has the advantage of identifying subtle differences in expression patterns within target organs. For example, genes expressed only in stamen tissue during the early stages of pollen development are likely to have an important function in controlling pollen formation. As noted by Dr. Martienssen "gene traps are powerful tools to examine both gene expression and gene function in animal and plant systems. Large scale studies like this are going to provide valuable information concerning regulatory networks and target genes". Dr. Irish added "using the gene trapping strategy, we have identified a host of new genes involved in floral development, as well as illuminating some of the processes involved in establishing different tissues and organs. This general approach is very effective in providing novel insights into development that are not easily gleaned using other available techniques." Many of the trapped genes were sequenced and identified, giving clues about how they might function in petal and stamen development. Floral organ development depends on appropriate specification and differentiation of the unique organ identities (e.g. petals, stamens, ovules). An interesting aspect of this research is the finding that the expression of many trapped genes is restricted to particular subdomains of the proximodistal axis of petals and stamens, implying that intensive regulation of patterning along this axis is critical for floral organ development. This research is an excellent example of how modern molecular biology techniques help to increase our understanding of complex biological processes. ### The research paper cited in this report is available at the
following link: ### The Plant Cell is published by the American Society of Plant Biologists. For more information about ASPB, please visit http://www.aspb.org/. |
The gene trap technique
used by Drs. Irish and Martienssen involved genetic transformation of Arabidopsis
plants with the reporter gene β-glucuronidase (GUS) lacking an external promoter
sequence to drive gene expression. Each transformation event leads to insertion
of the GUS gene at a random site within the plant genome. All endogenous genes
contain promoter sequences that determine where and when they will be expressed
in an organism. The reporter GUS gene, lacking its own promoter, will only be
expressed and produce the GUS protein if it happens to be inserted into the
plant genome in the immediate vicinity of an endogenous gene promoter. GUS activity
is assayed in transformed plants by treating harvested seedlings with a stain
that turns blue in the presence of GUS. Successful "gene trapped"
plants will show the characteristic blue stain in specific patterns in the organs
or tissues of interest. The endogenous gene corresponding to the trapped promoter
can be fished out of the genome and sequenced based on its proximity to the
inserted reporter gene. Further experiments can then be conducted, for example,
to examine the expression of the native gene in wild type plants and to investigate
gene function by creating mutant plants that either lack expression of or overproduce
the native protein.