Mutagenic action of Mitomycin C, causing chromatid abberations, was not random along the chromosomes but seemed to be confined to hot spots on chromosomes 6 and 7 (Gecheff, 1989). These regions were located next to the secondary constriction. The type of abberations were intercalary deletions and duplication-deletions.

Andy Kleinhofs is maintaining a list of barley cDNA and genomic clones. I've pulled the clones for chromosome 7 off that list. These include two dehydrin clones Dhn1 (plasmid plZ 19R-B8) and Dhn2 (plasmid pTZ19R-B9) (Close et al., 1989).

A protein 27 clone Paz32 (plasmid pc paz 1-3) (Heijgaard et al., 1985) a phosphoglycerate kinase clone (p.c. from S. Chao) and the rRNA spacer (p.c. from M. O'Dell) are also reported to be located on chromosome 7.

References:

Close, T. J., A. A. Kortt, and P. M. Chandler. 1989. A cDNA-based comparison of dehydration induced proteins (dehydrins) in barley and corn. Plant Molecular Biology l3:95-108.

Gecheff, K. I. 1989. Position specific effects in the mutagenic action of mitomycin C on the chromosomes of Hordeum vulgare L. Theor. Appl. Genet. 77:705-710.

Hejgaard, J. S., K. Rasmussen, A. Brandt, and I. Swendren. 1985. Sequence homology between barley endosperm protein Z and protease inhibitors of the X₁-antitrypsin family. FEBS 180:89-94.