Publications by authors named "Katherine S Lawrence"
The plant cell wall structure can be altered by pathogen-secreted polygalacturonases (PGs) that cleave the α-(1→4) linkages occurring between D-galacturonic acid residues in homogalacturonan. The activity of the PGs leads to cell wall maceration, facilitating infection. Plant PG inhibiting proteins (PGIPs) impede pathogen PGs, impairing infection and leading to the ability of the plant to resist infection.
View Article and Find Full Text PDFExpression of the central circadian oscillator components CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), TIMING OF CAB1 (TOC1), GIGANTEA (GI), and CONSTANS (CO) occurs in Glycine max root cells (syncytia) parasitized by the nematode Heterodera glycines while undergoing resistance, indicating a defense role. GmCCA1-1 relative transcript abundance (RTA) in roots experiencing overexpression (OE) or RNA interference (RNAi) is characterized by rhythmic oscillations, compared to a ribosomal protein gene (GmRPS21) control. A GmCCA1-1 RTA change, advancing by 12 h, exists in H.
View Article and Find Full Text PDFThe Glycine max xyloglucan endotransglycosylase/hydrolase (EC 2.4.1.
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- Glycine max (soybean) has 32 MAPKs, with 9 playing a role in defense against the plant parasitic nematode Heterodera glycines.
- RNA sequencing of transgenic lines overexpressing these MAPKs identified 309 genes regulated by the defense MAPKs, 71 of which are active in syncytia associated with nematode infection.
- Functional analyses of 8 secreted defense proteins revealed their role in plant defense, where overexpression reduces nematode life cycle completion, while RNA interference increases parasitism, highlighting the importance of MAPK signaling in plant defense mechanisms.
A Glycine max (soybean) hemicellulose modifying gene, xyloglucan endotransglycoslase/hydrolase (XTH43), has been identified as being expressed within a nurse cell known as a syncytium developing within the soybean root undergoing the process of defense to infection by the parasitic nematode, Heterodera glycines. The highly effective nature of XTH43 overexpression in suppressing H. glycines parasitism in soybean has led to experiments examining whether the heterologous expression of XTH43 in Gossypium hirsutum (upland cotton) could impair the parasitism of Meloidogyne incognita, that form a different type of nurse cell called a giant cell that is enclosed within a swollen root structure called a gall.
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- BRCA1 and BARD1 form an important E3 ubiquitin ligase for DNA damage repair, and their C. elegans counterparts, BRC-1 and BRD-1, also play a role in DNA repair and meiosis.
- Using GFP fusions, it was discovered that BRC-1 and BRD-1 localize in germ cells and co-localize with RAD-51, especially under replication stress.
- BRC-1-BRD-1's localization is crucial for proper meiotic recombination and chromosome synapsis, and their inactivation exacerbates embryonic lethality in mutants, indicating their checkpoint role at the synaptonemal complex.
The Caenorhabditis elegans SUN domain protein, UNC-84, functions in nuclear migration and anchorage in the soma. We discovered a novel role for UNC-84 in DNA damage repair and meiotic recombination. Loss of UNC-84 leads to defects in the loading and disassembly of the recombinase RAD-51.
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- Errors in DNA replication and segregation can cause DNA damage, mutations, and aneuploidies, so cells delay division to allow for repair.
- The DNA damage response (DDR) and spindle assembly checkpoint (SAC) work together in C. elegans germ cells to monitor DNA integrity and ensure proper mitosis, especially during metaphase.
- Both DDR and SAC are crucial for maintaining genome stability, where disturbances can lead to defects in chromosome alignment and inefficiencies in repairing DNA damage.
The spindle assembly checkpoint: More than just keeping track of the spindle.
Trends Cell Mol Biol
January 2015
Article Synopsis
- Genome stability is crucial for cell growth and survival, monitored by two main checkpoints: the DNA damage response (DDR) and the spindle assembly checkpoint (SAC).
- The DDR checks for DNA damage during the G1, S, and G2 phases, while the SAC ensures chromosomes are correctly arranged during the M phase of the cell cycle.
- Recent research shows that the DDR and SAC not only perform their specific functions but also interact and have overlapping roles, particularly during metaphase and in response to DNA damage.
Article Synopsis
- Meiosis relies on chromosome pairing and crossover recombination, with double-strand breaks (DSBs) being crucial for this process, particularly in the X chromosome of Caenorhabditis elegans males, which are hemizygous (having only one copy).
- The study shows that DSB formation and chromosome interactions in male germ cells are closely linked, and a temporary structure called pseudosynapsis allows sister chromatids on the X chromosome to behave similarly to homologous chromosomes during repair.
- Interestingly, X chromosome repair seems to bypass traditional homologous recombination pathways and can engage other methods like single-strand annealing, indicating a unique adaptation for the repair mechanisms in hemizygous sex chromosomes.