Maize pollen test systems to detect nondisjunction.

Three pollen test systems to detect the induction of nondisjunction in maize are actively being explored. (1) Each member of a tetrad of haploid microspores produced by meiosis contains a single chromosome 6 which carries the only nucleolar organizing region in the maize genome. Thus, each member of...

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Autor principal: Weber, D F
Formato: Texto
Lenguaje:English
Publicado: 1981
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1568637/
https://www.ncbi.nlm.nih.gov/pubmed/7460886
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author Weber, D F
author_facet Weber, D F
author_sort Weber, D F
collection PubMed
description Three pollen test systems to detect the induction of nondisjunction in maize are actively being explored. (1) Each member of a tetrad of haploid microspores produced by meiosis contains a single chromosome 6 which carries the only nucleolar organizing region in the maize genome. Thus, each member of a normal tetrad contains one nucleolus. If nondisjunction took place at the first or second meiotic division, 2:2:0:0 or 2:1:1:0 tetrads would be produced respectively. (2) If a male parent carrying a dominant endosperm marker is crossed by a female carrying a recessive allele of this gene, all normal kernels would be heterozygous and would express the dominant phenotype in their endosperm. If nondisjunction of the chromosome carrying this gene took place at the second microspore division and the nullisomic and disomic sperm fertilized the polar nuclei and egg of a given embryo sac respectively, an exceptional kernel is produced which would express the recessive endosperm phenotype and contain a trisomic embryo. (3) Complementing null mutations of genes expressed in individual pollen grains can be utilized to detect nondisjunction. Normal haploid pollen grains from plants heterozygous for two complementing null alleles of a locus would each express the recessive phenotype. If nondisjunction took place during either meiotic division, disomic pollen grains containing both alleles could be produced expressing the dominant phenotype due to complementation. We are exploring this test system utilizing appropriate alcohol dehydrogenase mutants.
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spelling pubmed-15686372006-09-19 Maize pollen test systems to detect nondisjunction. Weber, D F Environ Health Perspect Research Article Three pollen test systems to detect the induction of nondisjunction in maize are actively being explored. (1) Each member of a tetrad of haploid microspores produced by meiosis contains a single chromosome 6 which carries the only nucleolar organizing region in the maize genome. Thus, each member of a normal tetrad contains one nucleolus. If nondisjunction took place at the first or second meiotic division, 2:2:0:0 or 2:1:1:0 tetrads would be produced respectively. (2) If a male parent carrying a dominant endosperm marker is crossed by a female carrying a recessive allele of this gene, all normal kernels would be heterozygous and would express the dominant phenotype in their endosperm. If nondisjunction of the chromosome carrying this gene took place at the second microspore division and the nullisomic and disomic sperm fertilized the polar nuclei and egg of a given embryo sac respectively, an exceptional kernel is produced which would express the recessive endosperm phenotype and contain a trisomic embryo. (3) Complementing null mutations of genes expressed in individual pollen grains can be utilized to detect nondisjunction. Normal haploid pollen grains from plants heterozygous for two complementing null alleles of a locus would each express the recessive phenotype. If nondisjunction took place during either meiotic division, disomic pollen grains containing both alleles could be produced expressing the dominant phenotype due to complementation. We are exploring this test system utilizing appropriate alcohol dehydrogenase mutants. 1981-01 /pmc/articles/PMC1568637/ /pubmed/7460886 Text en
spellingShingle Research Article
Weber, D F
Maize pollen test systems to detect nondisjunction.
title Maize pollen test systems to detect nondisjunction.
title_full Maize pollen test systems to detect nondisjunction.
title_fullStr Maize pollen test systems to detect nondisjunction.
title_full_unstemmed Maize pollen test systems to detect nondisjunction.
title_short Maize pollen test systems to detect nondisjunction.
title_sort maize pollen test systems to detect nondisjunction.
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1568637/
https://www.ncbi.nlm.nih.gov/pubmed/7460886
work_keys_str_mv AT weberdf maizepollentestsystemstodetectnondisjunction