Related Experiment Videos
Developing expressed sequence tags (ESTs) from polymorphic transcript-derived fragments (TDFs) in cassava (Manihot
M C Suárez1, A Bernal, J Gutiérrez
1Biotechnology Research Unit, Centro International de Agricultura Tropical, Cali, Colombia.
Genome
|March 4, 2000
Summary
Researchers used cDNA-amplified fragment length polymorphism (cDNA-AFLP) to identify over 500 unique DNA fragments in cassava. These transcript-derived fragments (TDFs) proved more polymorphic than random cDNAs, aiding genetic mapping.
Area of Science:
- Genetics
- Molecular Biology
- Plant Science
Background:
- Genetic mapping is crucial for understanding complex traits in crops like cassava (Manihot esculenta).
- Developing informative genetic markers is essential for efficient gene mapping and breeding programs.
Purpose of the Study:
- To identify and map novel genetic markers in cassava using expressed sequence tags (ESTs).
- To evaluate the polymorphism level of transcript-derived fragments (TDFs) compared to random cDNAs for genetic mapping.
Main Methods:
- Applied cDNA-amplified fragment length polymorphism (cDNA-AFLP) to parental mRNA of a cassava mapping population.
- Cloned, sequenced, and mapped a subset of transcript-derived fragments (TDFs) as molecular markers.
- Compared the genetic mapping utility of TDFs with restriction fragment length polymorphism (RFLP) markers.
Main Results:
- Generated over 500 unique TDFs from parental cassava lines.
- Sequencing of 50 TDFs revealed mostly genes with unknown functions.
- Successfully mapped six TDFs onto the cassava genetic map.
- Demonstrated that TDFs exhibit higher polymorphism than random cDNAs when used as genetic markers.
Conclusions:
- cDNA-AFLP is an effective method for generating polymorphic ESTs in cassava.
- TDFs derived from cDNA-AFLP are valuable genetic markers, outperforming random cDNAs.
- Generating ESTs from differentially expressed sequences offers a strategy for candidate gene approaches in complex trait mapping.