BGN 19: Coordinator's report: Chromosome 3

Coordinator's report: Chromosome 3

T. Konishi
Research Institute for Bioresources
Okayama University
Kurashiki 710, Japan.


Three loci for esterase isozymes (Est1, Est2, and Est4) are tightly linked as a complex locus (Kahler and Allard, 1970; Nielsen and Frydenberg, 1971a), and located on chromosome 3 (Nieslen and Frydenberg, 1971b). Recently, Konishi and Matsuura (1987) found that Est4 locus is linked with the cu2 locus with a recombination value of 23.8 ± 1.79% and localized at the terminal of the long arm of chromosome 3. The recombination value was estimated to be 25.2 ± 4.08% after recalculation, using F2 and F3 data in the same combination (Konishi and Matsuura, 1990).

Furthermore, a new isozyme locus, Aat3 for aspartate aminotransferase-3, was found to be linked with uz locus with a recombination value of 3.2 ± 0.78%, suggesting that Aat3 locus is located near the centromere of chromosome 3 (Konishi and Matsuura, 1990).

The orientation of 18 loci on chromosome 3 was estimated by a computer program for the maximum likelihood method developed by Jensen and Jørgensen (1975), using data obtained in our institute (see the references in BGN 17:110). The result is indicated in Fig. 1.

References:

Kahler, A.L., and R. W. Allard. 1970. Genetics of isozyme variants in barley. I. Esterase. Crop Sci. 10:444-448.

Konishi, T., and S. Matsuura. 1987. Linkage analysis of Est-4 locus for esterase isozyme-4 in barley. BGN 17:68-70.

Konishi, T., and S. Matsuura. 1990. Chromosomal localization of two isozyme loci on chromosome 3 in barley. BGN 19:46-48.

Jensen, J., and J. Helms Jørgensen. 1975. The barley chromosome 5 linkage map. I. Literature survey and map estimation procedure. Hereditas 80:5-16.

Nielsen, G., and 0. Frydenberg. 1971a. The inheritance and distribution of esterase isozymes in barley. In Barley Genetics 11:14-22.

Nielsen, G., and 0. Frydenberg. 1971b. Chromosome localization of the esterase loci Est-1 and Est-2 in barley by means of trisomics. Hereditas 67:152-154.


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