Molecular cloning of the c locus

The c locus is involved in the regulation of anthocyanin biosynthesis and has been cloned using transposable elements as gene tags. The En1 element (Pereira, A., et al., EMBO J. 4:17-23, 1985) as well as the Ac element (Fedoroff, N., et al., Cell 35:235-242, 1983; Muller-Neumann, M., et al., Mol. Gen. Genet. 198:19-24, 1984) were used as probes to screen genomic libraries made from the En induced mutable c alleles c-m668655 and c-m668613 (Reddy, A., and Peterson, P.A., Mol. Gen. Genet. 192:21-31, 1983) and the Ds-induced mutant c-m2 (McClintock, B., Carnegie Inst. Yearbook 47:155-169). Three homologous clones could be isolated from these libraries. From the c-m668655 and c-m668613 libraries, one clone each was isolated which contained a complete 8.4kb En1 element. The screening of the c-m2 library revealed one clone containing a 2kb Ds element. The elements are integrated into a fragment about lkb in size.

From a wild type maize line (LC) a homologous clone could be isolated lacking transposable element specific sequences. A 1kb EcoRI fragment of this wild type clone has been used to probe poly A+ RNA from developing kernels (30 days after pollination) and lights up 3 transcripts of different sizes (1.6kb, 1.4kb, 0.3kb). A clone representing the C-I allele was also isolated. The analysis of this clone revealed long regions of DNA rearrangement (>11kb) compared to the wild type clone.

Javier Paz-Ares, Udo Wienand, Peter A. Peterson1 and Heinz Saedler

1Dept. of Agronomy, Iowa State University

Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.

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