Location: Hard Winter Wheat Genetics ResearchTitle: Analysis of single nucleotide polymorphism via genotyping-by-sequencing in the gall midge Mayetiola Destructor (Hessian Fly) Author
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2015
Publication Date: N/A
Citation: N/A Interpretive Summary: Hessian fly is a destructive pest of wheat and can overcome wheat resistance relatively quickly (within 3-8 years after the initial deployment of a resistance gene). To develop wheat cultivars with more durable resistance, we need a better understanding of the molecular mechanisms for Hessian fly avirulence and virulence. The first step to reveal the mechanism for Hessian fly avirulence/virulence is to map and clone Hessian fly avirulence/virulence genes. To map and clone Hessian fly avirulence genes, we need to identify useful molecular markers. In this research, we identified over 7,000 single nucleotide polymorphisms (SNPs) from three different Hessian fly populations. The identified SNPs could be converted into genetic markers for mapping Hessian fly avirulence and other interesting traits.
Technical Abstract: Genotyping-by-sequencing (GBS) is a recently developed technology that has been used to identify DNA markers and map genes for specific traits in many organisms. The gall midge Mayetiola destructor, commonly known as Hessian fly, is a global destructive pest of wheat. In this study, we identified 7039 SNPs in Hessian fly via GBS by sequencing 288 individual insects from three different populations. The identified SNPs are relatively evenly distributed across the four chromosomes based on chromosome size. Over 63% of the identified SNPs are transitional nucleotide substitutions, resulting in transition/transversion ratio 1.7. Twenty-seven percent of the identified SNPs were located within the exons of 573 genes that perform various functions. One of the interesting features of the identified SNPs is the unbalance between the two possible directions of nucleotide substitutions in certain types of SNPs. For example, the ratio between C'T and T'C transitions is 1.2, significantly different from each other (P<0.01). Another interesting feature is the over-representation (~43%) of the A'T transversion and under-representation (~12%) of G'C transversion. Over 98% of the identified SNP sites are heterozygous. The discovery of over-representation of a specific type of transversion and the unbalance between two possible directional substitutions of the same type of SNPs could be important for studying mutational mechanisms or the role of selection forces in both the Hessian fly and other genetic systems. The identified SNPs should be useful for population genetics, genotyping, and mapping of virulence and other important traits.