title: Heterozygous Mapping Strategy (HetMappS) for High Resolution Genotyping-By-Sequencing Markers: A Case Study in Grapevine.
abstract: Genotyping by sequencing (GBS) provides opportunities to generate high-resolution genetic maps at a low genotyping cost, but for highly heterozygous species, missing data and heterozygote undercalling complicate the creation of GBS genetic maps. To overcome these issues, we developed a publicly available, modular approach called HetMappS, which functions independently of parental genotypes and corrects for genotyping errors associated with heterozygosity. For linkage group formation, HetMappS includes both a reference-guided synteny pipeline and a reference-independent de novo pipeline. The de novo pipeline can be utilized for under-characterized or high diversity families that lack an appropriate reference. We applied both HetMappS pipelines in five half-sib F1 families involving genetically diverse Vitis spp. Starting with at least 116,466 putative SNPs per family, the HetMappS pipelines identified 10,440 to 17,267 phased pseudo-testcross (Pt) markers and generated high-confidence maps. Pt marker density exceeded crossover resolution in all cases; up to 5,560 non-redundant markers were used to generate parental maps ranging from 1,047 cM to 1,696 cM. The number of markers used was strongly correlated with family size in both de novo and synteny maps (r = 0.92 and 0.91, respectively). Comparisons between allele and tag frequencies suggested that many markers were in tandem repeats and mapped as single loci, while markers in regions of more than two repeats were removed during map curation. Both pipelines generated similar genetic maps, and genetic order was strongly correlated with the reference genome physical order in all cases. Independently created genetic maps from shared parents exhibited nearly identical results. Flower sex was mapped in three families and correctly localized to the known sex locus in all cases. The HetMappS pipeline could have wide application for genetic mapping in highly heterozygous species, and its modularity provides opportunities to adapt portions of the pipeline to other family types, genotyping technologies or applications.
authors.affiliation: Bioinformatics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America; Genomic Diversity Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Katie E
authors.initials: KE
authors.lastname: Hyma
authors.affiliation: Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, United States of America.
authors.forename: Paola
authors.initials: P
authors.lastname: Barba
authors.affiliation: Bioinformatics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Minghui
authors.initials: M
authors.lastname: Wang
authors.affiliation: USDA-ARS Grape Genetics Research Unit, Geneva, New York, United States of America.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Londo
authors.affiliation: Genomic Diversity Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Charlotte B
authors.initials: CB
authors.lastname: Acharya
authors.affiliation: Genomic Diversity Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Mitchell
authors.affiliation: Bioinformatics Facility, Institute of Biotechnology, Cornell University, Ithaca, New York, United States of America.
authors.forename: Qi
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Horticulture Section, School of Integrative Plant Science, Cornell University, Geneva, New York, United States of America.
authors.forename: Bruce
authors.initials: B
authors.lastname: Reisch
authors.affiliation: USDA-ARS Grape Genetics Research Unit, Geneva, New York, United States of America.
authors.forename: Lance
authors.initials: L
authors.lastname: Cadle-Davidson
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping / Q000379:methods*; D032461:Chromosomes, Plant / Q000235:genetics; D005787:Gene Frequency; D018745:Genome, Plant / Q000235:genetics; D005838:Genotype; D060005:Genotyping Techniques / Q000379:methods*; D006579:Heterozygote; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D018895:Microsatellite Repeats / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D015203:Reproducibility of Results; D026801:Synteny; D027843:Vitis / Q000145:classification / Q000235:genetics*