Brassinosteroid hormones are positive regulators of plant organ growth, yet their function in proliferating tissues remains unclear. Here, through integrating single-cell RNA sequencing with long-term live-cell imaging of the Arabidopsis root, we reveal that brassinosteroid activity fluctuates throughout the cell cycle, decreasing during mitotic divisions and increasing during the G1 phase. The post-mitotic recovery of brassinosteroid activity is driven by the intrinsic polarity of the mother cell, resulting in one daughter cell with enhanced brassinosteroid signaling, while the other supports brassinosteroid biosynthesis. The coexistence of these distinct daughter cell states during the G1 phase circumvents a negative feedback loop to facilitate brassinosteroid production while signaling increases. Our findings uncover polarity-guided, uneven mitotic divisions in the meristem, which control brassinosteroid hormone activity to ensure optimal root growth.
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http://dx.doi.org/10.1016/j.cell.2025.02.011 | DOI Listing |
Am J Surg Pathol
March 2025
Department of Dermatology, Feinberg School of Medicine.
Pediatric Spitz melanoma (SM) with bonafide metastatic disease is rare. In this study, we assembled the largest cohort to date of pediatric SM with a verified Spitz-associated genomic driver and clinical follow-up demonstrating bonafide metastasis. We compared the clinical, morphologic, and molecular features of these SMs to a control cohort of 57 pediatric atypical Spitz tumors (ASTs).
View Article and Find Full Text PDFCell
March 2025
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium; Center for Plant Systems Biology, VIB, Ghent 9052, Belgium. Electronic address:
Brassinosteroid hormones are positive regulators of plant organ growth, yet their function in proliferating tissues remains unclear. Here, through integrating single-cell RNA sequencing with long-term live-cell imaging of the Arabidopsis root, we reveal that brassinosteroid activity fluctuates throughout the cell cycle, decreasing during mitotic divisions and increasing during the G1 phase. The post-mitotic recovery of brassinosteroid activity is driven by the intrinsic polarity of the mother cell, resulting in one daughter cell with enhanced brassinosteroid signaling, while the other supports brassinosteroid biosynthesis.
View Article and Find Full Text PDFChromosoma
March 2025
DGIMI, Univ Montpellier, INRAE, Montpellier, France.
Some insects have holocentric chromosomes, with multiple kinetochores rather than a single centromere. They also lack the CENP-A and CENP-C proteins, suggesting a kinetochore assembly process different from that of monocentric chromosomes. The homolog of CENP-T was recently shown to bind silent chromatin and to play a key role in kinetochore assembly in Bombyx mori, but its role in other insects with holocentric chromosomes is unknown.
View Article and Find Full Text PDFMol Biol Cell
April 2025
Department of Molecular and Cell Biology, University of California at Davis, Davis, CA 95616.
The mitotic spindle, which uses microtubules (MTs) and MT-based motor proteins to separate sister chromosomes prior to cell division, contains abundant membranes, organelles, and protein assemblies derived from the familiar interphase intracellular membrane network. In this essay, mainly with reference to selected animal and fungal cells, I summarize current ideas about the reciprocal functional relationship between these mitotic spindle-associated membranes and the spindle MT cytoskeleton, in which; 1) spindle membranes control the composition, Ca ion concentration and mechanical performance of the spindle MT cytoskeleton; and conversely 2) the spindle MT cytoskeleton contributes to membrane/organelle partitioning and inheritance during cell division and serves as a reservoir of membranes, organelles, and vesicles for delivery to the interphase cytoplasm, plasma membrane, and cleavage furrow.
View Article and Find Full Text PDFClin Res Hepatol Gastroenterol
March 2025
Department of Allied Science, Graphic Era Hill University, Bhimtal, Uttarakhand, 248002; Graphic Era Deemed to be University, Dehradun, Uttarakhand, India. Electronic address:
Gastric cancer (GC), a leading cause of cancer-related mortality, poses a significant global health challenge. Given its complex etiology, understanding the molecular pathways driving GC progression is crucial for developing innovative therapeutic strategies. Among the diverse proteins involved in cellular transport and mitotic regulation, kinesin superfamily proteins (KIFs) have emerged as key players in tumor biology.
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