title: In Silico and Fluorescence In Situ Hybridization Mapping Reveals Collinearity between the Pennisetum squamulatum Apomixis Carrier-Chromosome and Chromosome 2 of Sorghum and Foxtail Millet.
abstract: Apomixis, or clonal propagation through seed, is a trait identified within multiple species of the grass family (Poaceae). The genetic locus controlling apomixis in Pennisetum squamulatum (syn Cenchrus squamulatus) and Cenchrus ciliaris (syn Pennisetum ciliare, buffelgrass) is the apospory-specific genomic region (ASGR). Previously, the ASGR was shown to be highly conserved but inverted in marker order between P. squamulatum and C. ciliaris based on fluorescence in situ hybridization (FISH) and varied in both karyotype and position of the ASGR on the ASGR-carrier chromosome among other apomictic Cenchrus/Pennisetum species. Using in silico transcript mapping and verification of physical positions of some of the transcripts via FISH, we discovered that the ASGR-carrier chromosome from P. squamulatum is collinear with chromosome 2 of foxtail millet and sorghum outside of the ASGR. The in silico ordering of the ASGR-carrier chromosome markers, previously unmapped in P. squamulatum, allowed for the identification of a backcross line with structural changes to the P. squamulatum ASGR-carrier chromosome derived from gamma irradiated pollen.
authors.affiliation: Department of Horticulture, University of Georgia-Tifton Campus, Tifton, Georgia, 31793, United States of America.
authors.forename: Sirjan
authors.initials: S
authors.lastname: Sapkota
authors.affiliation: Department of Horticulture, University of Georgia-Tifton Campus, Tifton, Georgia, 31793, United States of America.
authors.forename: Joann A
authors.initials: JA
authors.lastname: Conner
authors.affiliation: Department of Crop and Soil Sciences, University of Georgia-Tifton Campus, Tifton, Georgia, 31793, United States of America.
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Hanna
authors.affiliation: Department of Horticulture, University of Georgia-Tifton Campus, Tifton, Georgia, 31793, United States of America.
authors.forename: Bindu
authors.initials: B
authors.lastname: Simon
authors.affiliation: DuPont Pioneer, DuPont Pioneer, Johnston, Iowa, 50131, United States of America.
authors.forename: Kevin
authors.initials: K
authors.lastname: Fengler
authors.affiliation: DuPont Experimental Station, Wilmington, Delaware, 19803, United States of America.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Deschamps
authors.affiliation: DuPont Pioneer, DuPont Pioneer, Johnston, Iowa, 50131, United States of America.
authors.forename: Mark
authors.initials: M
authors.lastname: Cigan
authors.affiliation: Department of Horticulture, University of Georgia-Tifton Campus, Tifton, Georgia, 31793, United States of America.
authors.forename: Peggy
authors.initials: P
authors.lastname: Ozias-Akins
mesh_terms: D060832:Apomixis / Q000235:genetics; D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant; D020451:Contig Mapping; D008040:Genetic Linkage; D017404:In Situ Hybridization, Fluorescence; D031782:Pennisetum / Q000235:genetics*; D032983:Setaria Plant / Q000235:genetics; D045868:Sorghum / Q000235:genetics*