Department of Biochemistry, University of Otago, Dunedin, 9054, New Zealand.
Published: September 2014
AI Article Synopsis
Article Abstract
The MINICHROMOSOME MAINTENANCE 2-7 (MCM2-7) complex, a ring-shaped heterohexamer, unwinds the DNA double helix ahead of the other replication machinery. Although there is evidence that individual components might have other roles, the essential nature of the MCM2-7 complex in DNA replication has made it difficult to uncover these. Here, we present a detailed analysis of Arabidopsis thaliana mcm2-7 mutants and reveal phenotypic differences. The MCM2-7 genes are coordinately expressed during development, although MCM7 is expressed at a higher level in the egg cell. Consistent with a role in the egg cell, heterozygous mcm7 mutants resulted in frequent ovule abortion, a phenotype that does not occur in other mcm mutants. All mutants showed a maternal effect, whereby seeds inheriting a maternal mutant allele occasionally aborted later in seed development with defects in embryo patterning, endosperm nuclear size, and cellularization, a phenotype that is variable between subunit mutants. We provide evidence that this maternal effect is due to the necessity of a maternal store of MCM protein in the central cell that is sufficient for maintaining seed viability and size in the absence of de novo MCM transcription. Reducing MCM levels using endosperm-specific RNAi constructs resulted in the up-regulation of DNA repair transcripts, consistent with the current hypothesis that excess MCM2-7 complexes are loaded during G1 phase, and are required during S phase to overcome replicative stress or DNA damage. Overall, this study demonstrates the importance of the MCM2-7 subunits during seed development and suggests that there are functional differences between the subunits.
AbstractClimate change will affect both the mean and the variability in environmental conditions and may have major negative impacts on population densities in the future. For annual plants that already live in an extreme environment like the Sonoran Desert, keeping a fraction of their seeds dormant underground (for possibly years at a time) is critical to survive. Here, we consider how this form of bet hedging (i.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No.1, Nanjing, 210095, China.
A dwarf mutant with short branches (csdf) was identified from EMS-induced mutagenesis. Bulked segregant analysis sequencing and map-based cloning revealed CsKAO encoding ent-kaurenoic acid oxidase as the causal gene. Plant architecture is the primary target of artificial selection during domestication and improvement based on the determinate function for fruit yield.
Phenotypic plasticity plays an essential role in adaptive evolution. However, the molecular mechanisms of how genotype-by-environment interaction (G × E) effects shape phenotypic plasticity in marine organisms remain poorly understood. The crucial temperature-responsive trait triacylglycerol (TAG) content and its major gene adipose triglyceride lipase (Atgl) expression have divergent plastic patterns in two congeneric oyster species (Crassostrea gigas and Crassostrea angulata) to adapt to relative-cold/northern and relative-warm/southern habitats, respectively.
Rice is considered to be moderately salt-tolerant during germination, development, and ripening stages, and environmentally sensitive during seedling and reproductive stages, which affects seedling emergence and growth, resulting in significant yield losses. Seed conditioning with chitosan has been employed as a useful tool in high-salinity environments with the aim of increasing crop productivity and quality, as well as promoting more sustainable agricultural practices. Therefore, this study aimed to examine the effect of seed conditioning with chitosan on seed germination and rice seedling growth under salinity stress.
Recent studies have revealed the potential of tumor-infiltrating lymphocytes (TILs) to treat solid tumors effectively and safely. However, the translation of TIL therapy for patients is still hampered by non-standardized and laborious manufacturing procedures that are expensive and produce highly variable cellular products. To address these limitations, the CliniMACS Prodigy Tumor Reactive T cell (TRT) Process has been developed.
