Beltsville Agricultural Research Center
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Technology in the Cregan Lab



Soybean Map

Our primary research goal has been the development of molecular genetic markers that are used to create molecular genetic maps of the soybean genome. The soybean genome is made up of approximately 1.1 billion DNA units or basepairs in one set of its 20 pairs of chromosomes. Thus, the soybean molecular genetic map is actually composed of 20 separate maps corresponding to each of the 20 chromosome pairs. Initial research to develop the molecular genetic map of soybean was begun in the 1980ís in the laboratory of Dr. Randy Shoemaker (USDA, ARS, Ames, IA). This initial research relied on restriction fragment length polymorphism (RFLP) genetic markers. More recent work in our Laboratory at the USDA, ARS, Beltsville demonstrated the used of simple sequence repeat (SSR) or microsatellite DNA markers in plants. This discovery was followed by the development of an extensive set of SSR markers. More recently the laboratory has focused on the development and application of DNA markers based upon single changes in DNA basepairs referred to as single nucleotide polymorphisms (SNPs). Current work focuses on the discovery of SNP DNA markers in soybean genes (referred to a unigenes), the development of assays to rapidly and inexpensively detect these SNPs followed by genetic mapping of the SNP markers (and the unigenes in which they reside). This worked is being undertaken in collaboration with Dr. James Specht (Univ. of Nebraska-Lincoln), United Soybean Board Logo and Link Dr. Randy Shoemaker, (USDA, ARS, Ames, IA) and Dr. Gordon Lark (Univ. of Utah).


Our primary research goals are:
*  Discovery of  Single Nucleotide Polymorphisms (SNPs) in the soybean genome.
*  Development of assays for the detection and mapping of  SNPs using Flow Cytometry
* Creation of a SNP-based map of the soybean genome.
*  Applications of   SNPs and Simple Sequence Repeat  (SSR) DNA markers in soybean for gene and quantitative trait locus discovery.

* Targeted development of SNP and SSR markers to specific points of interest in the soybean genome.
* Application of SNP and SSR DNA markers to the genetic improvement of soybean via marker assisted selection.
* Application of SSR DNA markers for the identification of soybean cultivars and for use in quantifying genetic variation in soybean germplasm.
* Development of SSR DNA markers in wheat.

*  Take a look at our PCR Protocol or a PCR Animation

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  Updated: 08/2015