Mapping genes on an integrated sorghum genetic and physical map using cDNAselection technology

Childs, KL Klein, RR Klein, PE Morishige, DT Mullet, JE

Kl. Childs et al., Mapping genes on an integrated sorghum genetic and physical map using cDNAselection technology, PLANT J, 27(3), 2001, pp. 243-255

51

INGLESE

Article

Plant Sciences","Animal & Plant Sciences

PLANT JOURNAL

0960-7412 → ACNP

27

3

2001

243 - 255

ISI

0960-7412(200108)27:3<243:MGOAIS>2.0.ZU;2-A

Sorghum is an important target of plant genomics. This cereal has unusual t olerance to adverse environments, a small genome (750 Mbp) relative to most other grasses, a diverse germplasm, and utility for comparative genomics w ith rice, maize and other grasses. In this study, a modified cDNA selection protocol was developed to aid the discovery and mapping of genes across an integrated genetic and physical map of the sorghum genome. BAC DNA from th e sorghum genome map was isolated and covalently bound in arrayed tubes for efficient liquid handling. Amplifiable cDNA sequence tags were isolated by hybridization to individual sorghum BACs, cloned and sequenced. Analysis o f a fully sequenced sorghum BAC indicated that about 80% of known or predic ted genes were detected in the sequence tags, including multiple tags from different regions of individual genes. Data from cDNA selection using the f ully sequenced BAC indicate that the occurrence of mislocated cDNA tags is very low. Analysis of 35 BACs (5.25 Mb) from sorghum linkage group B reveal ed (and therefore mapped) two sorghum genes and 58 sorghum ESTs. Additional ly, 31 cDNA tags that had significant homologies to genes from other specie s were also isolated. The modified cDNA selection procedure described here will be useful for genome-wide gene discovery and EST mapping in sorghum, a nd for comparative genomics of sorghum, rice, maize and other grasses.