Poster: Genome evolution

Abs # 845: Aligning Physical and Functional Maps of a Genomic Region Spanning the Apomixis Locus by Exploiting Model Cereal Genomics

Presenter:	Conner, Joann A., jaconner@tifton.uga.edu
Authors	Conner, Joann A. (A)   Goel, Shailendra  (A)   Gunawan, Gunawati  (A)   Cordonnier-Pratt, Marie-Michele  (A)   Liang, Chun  (A)   Wang, Haiming  (A)   Pratt, Lee  (A)   Mullet, John E. (B)   Hanna, Wayne W. (A)   Ozias-Akins, Peggy  (A)
Affiliations:	(A): University of Georgia (B): Texas A&M University

Apomixis, defined as asexual reproduction through seed, is widespread among angiosperm families. We are studying apomixis in Pennisetum squamulatum and Cenchrus ciliaris, members of the Poaceae family, the most important crop plant family in the human food chain. All crop plants in this family reproduce sexually, although some wild relatives of maize, wheat, and pearl millet undergo asexual (apomictic) reproduction. Gene identification within the apospory-specific genomic region (ASGR) has been conducted through sample sequencing at 0.5X coverage of shotgun libraries from 36 overlapping or unique BAC clones containing approximately 2,730 kb of DNA genetically mapped to this region. Sequences were processed and analyzed for “genic” content using a bioinformatics pipeline developed at the University of Georgia. Our initial sequencing data suggest that the ASGR is transposon and retrotransposon rich, but gene poor. Gene identification at the ASGR could be greatly facilitated by the use of well developed molecular tools from related diploid model species such as sorghum and rice. We are therefore exploring the degree of macro and microsynteny between the “genic” sequences of the ASGR and both the rice and sorghum genome. Gene sequences were anchored to the rice and sorghum genome using hybridization to rice and sorghum BAC library filters. Results from the hybridization data were then analyzed for correspondence with sequence comparisons using a strictly bioinformatics approach in rice.