Submitted to: Molecular Ecology Notes
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/1/2006
Publication Date: 6/30/2006
Citation: Schemerhorn, B.J., Crane, Y.M. 2006. Development of microsatellite genetic markers in Hessian fly (Mayetiola destructor). Molecular Ecology Notes. 44(3):3-10. Interpretive Summary: Mayetiola destructor is a major insect pest of wheat crops. It is estimated that the fly causes at least $100 million a year in crop losses in the United States. Little information however is available on the population dynamics of M. destructor in the United States. Microsatellites are relatively short repeated DNA sequences. These loci have been described as powerful markers for population genetics because of their abundance throughout the eukaryotic genomes, high polymorphism, codominance, and ease of scoring. The purpose of this work was to create a microsatellite library from which a number of loci could be used for subsequent work on Hessian fly (Mayetiola destructor). This work can include population genetic work, marker-assisted selection, and mapping of other traits such as virulence as point loci or QTL (quantitative trait loci). The microsatellite library was enriched for microsatellites, in which size-selected DNA is screened with repeats motifs to find microsatellites. Over 52,000 clones were recovered, 8200+ were PCR screened and 2300+ were sequenced. There was a positive success rate of almost 75% of the original clones containing a microsatellite. The microsatellites were tested on four biotypes of Hessian fly, and ultimately 15 were found to be variable, amplifying at a single locus, and easily scored via capillary electrophoresis. The impact of this research is important on gaining a thorough understanding of Hessian fly population dynamics, the spread of virulence through populations and the prevention of additional crop loss due to unforeseen Hessian fly infestations.
Technical Abstract: Microsatellite libraries enriched in eight motifs (AC, GTG, CAG, GAA, AAC, TTA, GA, and TA) were prepared from size-selected genomic DNA of Hessian fly (Mayetiola destructor). From 67.8 to 95.6% of 52,224 recovered clones hybridized with microsatellite motif-specific probes. Of these, 8256 clones were PCR screened, and 2350 of them were successfully sequenced, of which 55.8% contained one or more perfect microsatellites, and another 19.5% contained at least one imperfect microsatellite. Polymorphism and reliability were tested in four Hessian fly biotypes, D, GP, O, and L, for 50 of the microsatellites in agarose gels. Twenty microsatellites were further tested with capillary electrophoresis. Of these, 17 behaved as a polymorphic single locus, two were invariant, and one represented a multiple locus.