Analysis of Nondisjunction Induced by the R-X1 Deficiency During Microsporogenesis in Zea-Mays L

Zhao, Zuo-Yu, Weber, D. (August 1988) Analysis of Nondisjunction Induced by the R-X1 Deficiency During Microsporogenesis in Zea-Mays L. Genetics, 119 (4). pp. 975-980. ISSN 0016-6731

Abstract

The r-X1 deficiency in maize induces nondisjunction at the second mitotic division during embryo sac formation. However, it was not known if this deficiency also induces nondisjunction during the microspore divisions. Microsporogenesis in the plants lacking or containing this deficiency was compared using two approaches. First, chromosome numbers were determined in generative nuclei. Many (8.3%) of the generative nuclei in r-X1-containing plants were aneuploid; however, those from control plants were all haploid. Thus, this deficiency induces nondisjunction during the first microspore division. Second, nucleoli were analyzed in microspores. The only nucleolar organizing region in maize is on chromosome 6. If chromosome 6 underwent nondisjunction during the first microspore division, one nucleus in binucleate microspores would contain no nucleolus and the other would contain two nucleoli (or one nucleolus if the nucleoli fused). Only one (0.03%) microspore of this type was observed in control plants while 1.12% were found in r-X1-containing plants. Thus, the r-X1 deficiency induces nondisjunction of chromosome 6 during the first microspore division. However, both of the sperm nuclei in trinucleate microspores contained one nucleolus in r-X1-containing and control plants; thus, this deficiency does not induce nondisjunction of chromosome 6 (and presumably other chromosomes) during the second microspore division.

Item Type: Paper
Subjects: organism description > plant > maize
organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell division
CSHL Authors:
Communities: CSHL labs
Depositing User: Gail Sherman
Date: August 1988
Date Deposited: 14 Sep 2017 19:50
Last Modified: 14 Sep 2017 19:50
PMCID: PMC1203480
Related URLs:
URI: https://repository.cshl.edu/id/eprint/35233

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