Abstract
Background:Complex haploinsufficiency is characterized by individuals with two heterozygous loci producing a phenotype that is not seen in either of the corresponding single-locus heterozygous individuals. The mutants of the anaphase-promoting complex/cyclosome (APC/C) subunit geneAPC11and the mitotic cyclin geneCYCLIN A1;2/TARDY ASYNCHRONOUS MEIOSIS(TAM) inArabidopsis thalianaare embryo-lethal and defective in meiosis, respectively, but their heterozygous single mutants do not exhibit defective embryo development and seed germination.Methods:Crosses between two heterozygousapc11mutant alleles and two homozygoustammutant alleles, and between two heterozygousapc11mutant alleles and aTAM:TAM-GFPline were conducted. Phenotypes of the F1seeds were analyzed by light microscopy.Results:We found that F1embryos from the crosses between heterozygousapc11-1(APC11/apc11-1) and homozygoustam-2(tam-2/tam-2) or betweenAPC11/apc11-2andtam-2/tam-2were morphologically normal but all the seeds failed to germinate. F1embryos from the crosses betweenAPC11/apc11-2andtam-1/tam-1(weaker allele thantam-2) produced morphologically normal seeds that germinated to form mature plants. However, F1embryos from the crosses betweenAPC11/apc11-1andtam-1/tam-1were abnormal and the seeds failed to germinate. Moreover, F1embryos from the crosses betweenAPC11/apc11-1and aTAM:TAM-GFPline were arrested at early developmental stages while F1embryos from the crosses betweenAPC11/apc11-2and theTAM:TAM-GFPline appeared fully developed but the seeds failed to germinate.Conclusions:Our observations indicate that theapc11andtammutants have an allele-dependent complex haploinsufficient relationship in embryo development and seed germination.
Funder
Ministry of Science and Technology of the People's Republic of China
Subject
General Pharmacology, Toxicology and Pharmaceutics,General Immunology and Microbiology,General Biochemistry, Genetics and Molecular Biology,General Medicine