1. Detailed analysis of a contiguous 22-Mb region of the maize genome.
- Author
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Fusheng Wei, Joshua C Stein, Chengzhi Liang, Jianwei Zhang, Robert S Fulton, Regina S Baucom, Emanuele De Paoli, Shiguo Zhou, Lixing Yang, Yujun Han, Shiran Pasternak, Apurva Narechania, Lifang Zhang, Cheng-Ting Yeh, Kai Ying, Dawn H Nagel, Kristi Collura, David Kudrna, Jennifer Currie, Jinke Lin, Hyeran Kim, Angelina Angelova, Gabriel Scara, Marina Wissotski, Wolfgang Golser, Laura Courtney, Scott Kruchowski, Tina A Graves, Susan M Rock, Stephanie Adams, Lucinda A Fulton, Catrina Fronick, William Courtney, Melissa Kramer, Lori Spiegel, Lydia Nascimento, Ananth Kalyanaraman, Cristian Chaparro, Jean-Marc Deragon, Phillip San Miguel, Ning Jiang, Susan R Wessler, Pamela J Green, Yeisoo Yu, David C Schwartz, Blake C Meyers, Jeffrey L Bennetzen, Robert A Martienssen, W Richard McCombie, Srinivas Aluru, Sandra W Clifton, Patrick S Schnable, Doreen Ware, Richard K Wilson, and Rod A Wing
- Subjects
Genetics ,QH426-470 - Abstract
Most of our understanding of plant genome structure and evolution has come from the careful annotation of small (e.g., 100 kb) sequenced genomic regions or from automated annotation of complete genome sequences. Here, we sequenced and carefully annotated a contiguous 22 Mb region of maize chromosome 4 using an improved pseudomolecule for annotation. The sequence segment was comprehensively ordered, oriented, and confirmed using the maize optical map. Nearly 84% of the sequence is composed of transposable elements (TEs) that are mostly nested within each other, of which most families are low-copy. We identified 544 gene models using multiple levels of evidence, as well as five miRNA genes. Gene fragments, many captured by TEs, are prevalent within this region. Elimination of gene redundancy from a tetraploid maize ancestor that originated a few million years ago is responsible in this region for most disruptions of synteny with sorghum and rice. Consistent with other sub-genomic analyses in maize, small RNA mapping showed that many small RNAs match TEs and that most TEs match small RNAs. These results, performed on approximately 1% of the maize genome, demonstrate the feasibility of refining the B73 RefGen_v1 genome assembly by incorporating optical map, high-resolution genetic map, and comparative genomic data sets. Such improvements, along with those of gene and repeat annotation, will serve to promote future functional genomic and phylogenomic research in maize and other grasses.
- Published
- 2009
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