Mode Of Cell Division Research Articles

"Candidatus Uabimicrobium helgolandensis"-a planctomycetal bacterium with phagocytosis-like prey cell engulfment, surface-dependent motility, and cell division.

The unique cell biology presented by members of the phylum Planctomycetota has puzzled researchers ever since their discovery. Initially thought to have eukaryotic-like features, their traits are now recognized as exceptional but distinctly bacterial. However, recently discovered strains again added novel and stunning aspects to the planctomycetal cell biology-shapeshifting by members of the "Saltatorellus" clade to an extent that is unprecedented in any other bacterial phylum, and phagocytosis-like cell engulfment in the bacterium "Candidatus Uabimicrobium amorphum." These recent additions to the phylum Planctomycetota indicate hitherto unexplored members with unique cell biology, which we aimed to make accessible for further investigations. Targeting bacteria with features like "Ca. U. amorphum", we first studied both the morphology and behavior of this microorganism in more detail. While similar to eukaryotic amoeboid organisms at first sight, we found "Ca. U. amorphum" to be rather distinct in many regards. Presenting a detailed description of "Ca. U. amorphum," we furthermore found this organism to divide in a fashion that has never been described in any other organism. Employing the obtained knowledge, we isolated a second "bacterium of prey" from the harbor of Heligoland Island (North Sea, Germany). Our isolate shares key features with "Ca. U. amorphum": phagocytosis-like cell engulfment, surface-dependent motility, and the same novel mode of cell division. Being related to "Ca. U. amorphum" within genus thresholds, we propose the name "Ca. Uabimicrobium helgolandensis" for this strain.IMPORTANCE"Candidatus Uabimicrobium helgolandensis" HlEnr_7 adds to the explored bacterial biodiversity with its phagocytosis-like uptake of prey bacteria. Enrichment of this strain indicates that there might be "impossible" microbes out there, missed by metagenomic analyses. Such organisms have the potential to challenge our understanding of nature. For example, the origin of eukaryotes remains enigmatic, with a contentious debate surrounding both the mitochondrial host entity and the moment of uptake. Currently, favored models involve a proteobacterium as the mitochondrial progenitor and an Asgard archaeon as the fusion partner. Models in which a eukaryotic ancestor engulfed the mitochondrial ancestor via phagocytosis had been largely rejected due to bioenergetic constraints. Thus, the phagocytosis-like abilities of planctomycetal bacteria might influence the debate, demonstrating that prey engulfment is possible in a prokaryotic cellular framework.

Stem Cell Division and Its Critical Role in Mammary Gland Development and Tumorigenesis: Current Progress and Remaining Challenges.

The origin of breast cancer (BC) has traditionally been a focus of medical research. It is widely acknowledged that BC originates from immortal mammary stem cells and that these stem cells participate in two division modes: symmetric cell division (SCD) and asymmetrical cell division (ACD). Although both of these modes are key to the process of breast development and their imbalance is closely associated with the onset of BC, the molecular mechanisms underlying these phenomena deserve in-depth exploration. In this review, we first outline the molecular mechanisms governing ACD/SCD and analyze the role of ACD/SCD in various stages of breast development. We describe that the changes in telomerase activity, the role of polar proteins, and the stimulation of ovarian hormones subsequently lead to two distinct consequences: breast development or carcinogenesis. Finally, gene mutations, abnormalities in polar proteins, modulation of signal-transduction pathways, and alterations in the microenvironment disrupt the balance of BC stem cell division modes and cause BC. Important regulatory factors such as mammalian Inscuteable mInsc, Numb, Eya1, PKCα, PKCθ, p53, and IL-6 also play significant roles in regulating pathways of ACD/SCD and may constitute key targets for future research on stem cell division, breast development, and tumor therapy.

An untargeted cultivation approach revealed Pseudogemmatithrix spongiicola gen. nov., sp. nov., and sheds light on the gemmatimonadotal mode of cell division: binary fission

Members of the phylum Gemmatimonadota can account for up to 10% of the phylogenetic diversity in bacterial communities. However, a detailed investigation of their cell biology and ecological roles is restricted by currently only six characterized species. By combining low-nutrient media, empirically determined inoculation volumes and long incubation times in a 96-well plate cultivation platform, we isolated two strains from a limnic sponge that belong to this under-studied phylum. The characterization suggests that the two closely related strains constitute a novel species of a novel genus, for which we introduce the name Pseudogemmatithrix spongiicola. The here demonstrated isolation of novel members from an under-studied bacterial phylum substantiates that the cultivation platform can provide access to axenic bacterial cultures from various environmental samples. Similar to previously described members of the phylum, the novel isolates form spherical appendages at the cell poles that were believed to be daughter cells resulting from asymmetric cell division by budding. However, time-lapse microscopy experiments and quantitative image analysis showed that the spherical appendages never grew or divided. Although the role of these spherical cells remains enigmatic, our data suggests that cells of the phylum Gemmatimonadota divide via FtsZ-based binary fission with different division plane localization patterns than in other bacterial phyla.

A cell fate decision map reveals abundant direct neurogenesis bypassing intermediate progenitors in the human developing neocortex

The human neocortex has undergone strong evolutionary expansion, largely due to an increased progenitor population, the basal radial glial cells. These cells are responsible for the production of a diversity of cell types, but the successive cell fate decisions taken by individual progenitors remain unknown. Here we developed a semi-automated live/fixed correlative imaging method to map basal radial glial cell division modes in early fetal tissue and cerebral organoids. Through the live analysis of hundreds of dividing progenitors, we show that basal radial glial cells undergo abundant symmetric amplifying divisions, and frequent self-consuming direct neurogenic divisions, bypassing intermediate progenitors. These direct neurogenic divisions are more abundant in the upper part of the subventricular zone. We furthermore demonstrate asymmetric Notch activation in the self-renewing daughter cells, independently of basal fibre inheritance. Our results reveal a remarkable conservation of fate decisions in cerebral organoids, supporting their value as models of early human neurogenesis.

Progeny counter mechanism in malaria parasites is linked to extracellular resources.

Malaria is caused by the rapid proliferation of Plasmodium parasites in patients and disease severity correlates with the number of infected red blood cells in circulation. Parasite multiplication within red blood cells is called schizogony and occurs through an atypical multinucleated cell division mode. The mechanisms regulating the number of daughter cells produced by a single progenitor are poorly understood. We investigated underlying regulatory principles by quantifying nuclear multiplication dynamics in Plasmodium falciparum and knowlesi using super-resolution time-lapse microscopy. This confirmed that the number of daughter cells was consistent with a model in which a counter mechanism regulates multiplication yet incompatible with a timer mechanism. P. falciparum cell volume at the start of nuclear division correlated with the final number of daughter cells. As schizogony progressed, the nucleocytoplasmic volume ratio, which has been found to be constant in all eukaryotes characterized so far, increased significantly, possibly to accommodate the exponentially multiplying nuclei. Depleting nutrients by dilution of culture medium caused parasites to produce fewer merozoites and reduced proliferation but did not affect cell volume or total nuclear volume at the end of schizogony. Our findings suggest that the counter mechanism implicated in malaria parasite proliferation integrates extracellular resource status to modify progeny number during blood stage infection.

Diversification of division mechanisms in endospore-forming bacteria revealed by analyses of peptidoglycan synthesis in Clostridioides difficile

The bacterial enzymes FtsW and FtsI, encoded in the highly conserved dcw gene cluster, are considered to be universally essential for the synthesis of septal peptidoglycan (PG) during cell division. Here, we show that the pathogen Clostridioides difficile lacks a canonical FtsW/FtsI pair, and its dcw-encoded PG synthases have undergone a specialization to fulfill sporulation-specific roles, including synthesizing septal PG during the sporulation-specific mode of cell division. Although these enzymes are directly regulated by canonical divisome components during this process, dcw-encoded PG synthases and their divisome regulators are dispensable for cell division during normal growth. Instead, C. difficile uses a bifunctional class A penicillin-binding protein as the core divisome PG synthase, revealing a previously unreported role for this class of enzymes. Our findings support that the emergence of endosporulation in the Firmicutes phylum facilitated the functional repurposing of cell division factors. Moreover, they indicate that C. difficile, and likely other clostridia, assemble a distinct divisome that therefore may represent a unique target for therapeutic interventions.

ABA signaling converts stem cell fate by substantiating a tradeoff between cell polarity, growth and cell cycle progression and abiotic stress responses in the moss Physcomitrium patens

Abscisic acid (ABA)-mediated abiotic stress tolerance causes plant growth inhibition. Under such stress conditions, some mosses generate de novo stress-resistant stem cells, also called brood cells or brachycytes, that do not exist under normal conditions. However, the cell physiological basis of the growth inhibition and the stem cell formation is not well understood. Here, we show that the ABA-induced growth inhibition of the moss Physcomitrium patens apical protonemal cells (protonemal stem cells) is mediated through a shift from asymmetric to symmetric cell division. This change of the cell division mode, and consequently change of stem cell activity, is substantiated by dampening cell polarity and cell proliferative activity through the altered distribution of cytoskeletal elements, the mitotic spindle and the vacuole, which results in the production of stress-resistant stem cells. Alteration of the cell physiological data is supported by the results of RNAseq analysis indicating rapid changes in both cell polarity and cell cycle regulation, while long-term treatments with ABA for 5 to 10 days impact mainly the transcriptional and translational regulation. The regulation of cell polarity and cell cycle genes suggests growth arrest mediated by small GTPases (ROPs) and their guanine exchange factors (ROPGEFs) and by cyclin and cyclin-dependent-kinase complex, respectively. Our data suggest that a tradeoff relationship between growth ability and abiotic stress response in the moss is substantiated by ABA signaling to suppress cell polarity and asymmetric cell growth and may play a pivotal role in stem cell fate conversion to newly produced stress-resistant stem cells.

Targeting polyploid giant cancer cells potentiates a therapeutic response and overcomes resistance to PARP inhibitors in ovarian cancer.

To understand the mechanism of acquired resistance to poly(ADP-ribose) polymerase inhibitors (PARPi) olaparib, we induced the formation of polyploid giant cancer cells (PGCCs) in ovarian and breast cancer cell lines, high-grade serous cancer (HGSC)-derived organoids, and patient-derived xenografts (PDXs). Time-lapse tracking of ovarian cancer cells revealed that PGCCs primarily developed from endoreplication after exposure to sublethal concentrations of olaparib. PGCCs exhibited features of senescent cells but, after olaparib withdrawal, can escape senescence via restitutional multipolar endomitosis and other noncanonical modes of cell division to generate mitotically competent resistant daughter cells. The contraceptive drug mifepristone blocked PGCC formation and daughter cell formation. Mifepristone/olaparib combination therapy substantially reduced tumor growth in PDX models without previous olaparib exposure, while mifepristone alone decreased tumor growth in PDX models with acquired olaparib resistance. Thus, targeting PGCCs may represent a promising approach to potentiate the therapeutic response to PARPi and overcome PARPi-induced resistance.

DOT1L activity affects neural stem cell division mode and reduces differentiation and ASNS expression.

Cortical neurogenesis depends on the balance between self-renewal and differentiation of apical progenitors (APs). Here, we study the epigenetic control of AP's division mode by focusing on the enzymatic activity of the histone methyltransferase DOT1L. Combining lineage tracing with single-cell RNA sequencing of clonally related cells, we show at the cellular level that DOT1L inhibition increases neurogenesis driven by a shift of APs from asymmetric self-renewing to symmetric neurogenic consumptive divisions. At the molecular level, DOT1L activity prevents AP differentiation by promoting transcription of metabolic genes. Mechanistically, DOT1L inhibition reduces activity of an EZH2/PRC2 pathway, converging on increased expression of asparagine synthetase (ASNS), a microcephaly associated gene. Overexpression of ASNS in APs phenocopies DOT1L inhibition, and also increases neuronal differentiation of APs. Our data suggest that DOT1L activity/PRC2 crosstalk controls AP lineage progression by regulating asparagine metabolism.

Determining Germ Cells in Flowering Plants: Common Concepts and Molecular Mechanisms Steering Meiocyte Specification and Mode of Cell Division

Determining Germ Cells in Flowering Plants: Common Concepts and Molecular Mechanisms Steering Meiocyte Specification and Mode of Cell Division

Cooperation between primary cilia signaling and integrin receptor extracellular matrix engagement regulates progenitor proliferation and neuronal differentiation in the developing cerebellum.

Neural progenitors and their neuronal progeny are bathed in extrinsic signals that impact critical decisions like the mode of cell division, how long they should reside in specific neuronal laminae, when to differentiate, and the timing of migratory decisions. Chief among these signals are secreted morphogens and extracellular matrix (ECM) molecules. Among the many cellular organelles and cell surface receptors that sense morphogen and ECM signals, the primary cilia and integrin receptors are some of the most important mediators of extracellular signals. Despite years of dissecting the function of cell-extrinsic sensory pathways in isolation, recent research has begun to show that key pathways work together to help neurons and progenitors interpret diverse inputs in their germinal niches. This mini-review utilizes the developing cerebellar granule neuron lineage as a model that highlights evolving concepts on the crosstalk between primary cilia and integrins in the development of the most abundant neuronal type in the brains of mammals.

Dinoflagellate Amphiesmal Dynamics: Cell Wall Deposition with Ecdysis and Cellular Growth.

Dinoflagellates are a major aquatic protist group with amphiesma, multiple cortical membranous "cell wall" layers that contain large circum-cortical alveolar sacs (AVs). AVs undergo extensive remodeling during cell- and life-cycle transitions, including ecdysal cysts (ECs) and resting cysts that are important in some harmful algal bloom initiation-termination. AVs are large cortical vesicular compartments, within which are elaborate cellulosic thecal plates (CTPs), in thecate species, and the pellicular layer (PL). AV-CTPs provide cellular mechanical protection and are targets of vesicular transport that are replaced during EC-swarmer cell transition, or with increased deposition during the cellular growth cycle. AV-PL exhibits dynamical-replacement with vesicular trafficking that are orchestrated with amphiesmal chlortetracycline-labeled Ca2+ stores signaling, integrating cellular growth with different modes of cell division cycle/progression. We reviewed the dynamics of amphiesma during different cell division cycle modes and life cycle stages, and its multifaceted regulations, focusing on the regulatory and functional readouts, including the coral-zooxanthellae interactions.

Significance of the Nudiform and Tectiform Modes of Silica Deposition, Lorica Assembly and Cell Division in Choanoflagellates as Exemplified by Stephanoeca diplocostata and Enibas spp.

The deposition of silicified costal strips and lorica assembly in choanoflagellates is precisely linked to the cell cycle. A minority of species undergo nudiform division whereby a loricate cell divides to produce a naked daughter cell that deposits a set of costal strips and then assembles a lorica. Most species undergo tectiform division whereby a parent loricate cell produces a set of costal strips, divides and passes on the stored strips to a daughter cell that immediately assembles a lorica. Many phylogenetic analyses recover nudiform and tectiform species as sister-clades giving the impression that they are distinct evolutionary lineages. However, the tectiform species Stephanoeca diplocostata is capable of undergoing nudiform division and depositing costal strips and assembling a lorica with certain modifications in a nudiform manner. The recent discovery of a new genus, Enibas, comprising species with Stephanoeca-like loricae that undergo nudiform cell division and on phylogenetic analysis occur as a sister group to other nudiform species has drawn attention to whether there are also unique features in lorica construction. A range of Enibas loricae is illustrated and it appears that there are unique features which might be interpreted as being derived from a Stephanoeca-like ancestor.

Evolution of longitudinal division in multicellular bacteria of the Neisseriaceae family

Rod-shaped bacteria typically elongate and divide by transverse fission. However, several bacterial species can form rod-shaped cells that divide longitudinally. Here, we study the evolution of cell shape and division mode within the family Neisseriaceae, which includes Gram-negative coccoid and rod-shaped species. In particular, bacteria of the genera Alysiella, Simonsiella and Conchiformibius, which can be found in the oral cavity of mammals, are multicellular and divide longitudinally. We use comparative genomics and ultrastructural microscopy to infer that longitudinal division within Neisseriaceae evolved from a rod-shaped ancestor. In multicellular longitudinally-dividing species, neighbouring cells within multicellular filaments are attached by their lateral peptidoglycan. In these bacteria, peptidoglycan insertion does not appear concentric, i.e. from the cell periphery to its centre, but as a medial sheet guillotining each cell. Finally, we identify genes and alleles associated with multicellularity and longitudinal division, including the acquisition of amidase-encoding gene amiC2, and amino acid changes in proteins including MreB and FtsA. Introduction of amiC2 and allelic substitution of mreB in a rod-shaped species that divides by transverse fission results in shorter cells with longer septa. Our work sheds light on the evolution of multicellularity and longitudinal division in bacteria, and suggests that members of the Neisseriaceae family may be good models to study these processes due to their morphological plasticity and genetic tractability.

Inner membrane complex proteomics reveals a palmitoylation regulation critical for intraerythrocytic development of malaria parasite.

Malaria is caused by infection of the erythrocytes by the parasites Plasmodium. Inside the erythrocytes, the parasites multiply via schizogony, an unconventional cell division mode. The inner membrane complex (IMC), an organelle located beneath the parasite plasma membrane, serving as the platform for protein anchorage, is essential for schizogony. So far, the complete repertoire of IMC proteins and their localization determinants remain unclear. Here we used biotin ligase (TurboID)-based proximity labeling to compile the proteome of the schizont IMC of the rodent malaria parasite Plasmodium yoelii. In total, 300 TurboID-interacting proteins were identified. 18 of 21 selected candidates were confirmed to localize in the IMC, indicating good reliability. In light of the existing palmitome of Plasmodium falciparum, 83 proteins of the P. yoelii IMC proteome are potentially palmitoylated. We further identified DHHC2 as the major resident palmitoyl-acyl-transferase of the IMC. Depletion of DHHC2 led to defective schizont segmentation and growth arrest both in vitro and in vivo. DHHC2 was found to palmitoylate two critical IMC proteins CDPK1 and GAP45 for their IMC localization. In summary, this study reports an inventory of new IMC proteins and demonstrates a central role of DHHC2 in governing the IMC localization of proteins during the schizont development.

P-163 Effects of Early Modes of Cell Division on Blastocyst Ploidy

Abstract Study question Abnormal cleavage (AC) has been confirmed at early development. We performed an NGS analysis on AC-derived blastocysts to investigate ploidy of the resulting embryos. Summary answer Group in which AC occurred during second division showed significantly higher rates for embryos appropriate for transfer than group where AC occurred during first division. What is known already Early division is important in embryogenesis and serves as an indicator of subsequent embryonic development. The occurrence of AC during early development can be identified with the advent of the time-lapse incubator, which in turn has led to difficulties in determining whether such AC-derived blastocysts can be used embryo transfer. In this study, we performed NGS analysis on AC-derived blastocysts to investigate the ploidy of the resulting embryos. Study design, size, duration The subjects comprised women from whom oocytes were collected for NGS analysis from January 2019 to November 2021. Retrospective analysis was performed using a time-lapse system (EmbryoScope+). Embryos were categorized into two groups: those with abnormal divisions observed during the first and second divisions and those in which normal divisions were observed in the same cycle. Participants/materials, setting, methods The group with AC observed was designated the AC group and the other with normal divisions as the Normal Cleavage (NC) group. Within the AC group, the subgroup with AC observed during first division was designated as the First (AC-F) group and the subgroup with AC observed during second division as the Second (AC-S) group for comparing the acquisition rates for euploidy embryos and embryos appropriate for transfer. Main results and the role of chance The AC group (17.3%) showed a significantly lower rate of good blastocyst formation than did the NC group (53.4%) (P < 0.01). The cutoff point for mosaicism was defined as > 20% of abnormal cells. Percentage <20 were classified as normal (euploid); >80, abnormal (aneuploidy); and 20-80, mosaic. Using a cutoff of 50% to differentiate ‘‘low’’ mosaics from ‘‘high’’ mosaics. There was no difference between the two groups in the acquisition rates for euploidy embryos (30.8-35.1%) and the embryos appropriate for transfer, including low-mosaic ones (44.3-46.1%). There also was no difference in the acquisition rates for euploidy embryos (24.0-37.0%) between the AC-F and AC-S groups. However, the AC-S group (59.3%) showed significantly higher acquisition rates than the AC-F group (32.0%) for the embryos appropriate for transfer, including low-mosaic ones (P < 0.05). Limitations, reasons for caution PGT-A is still under clinical research in Japan. Wider implications of the findings The group in which AC occurred during second division showed significantly higher acquisition rates for the embryos appropriate for transfer than the group in which AC occurred during first division. This indicates that the most important factor for identifying euploidy embryos is going through the two-cell phase during first division. Trial registration number not applicable

Preprint Highlight: Hyphal compartmentalization and sporulation in Streptomyces require the conserved cell division protein SepX.

Most bacteria undergo binary division. Streptomyces, filamentous soil bacteria with a multicellular life cycle, have two functionally distinct modes of cell division: vegetative cross-wall formation and sporulation septation. Although sporulation septation is an important survival strategy, the physiological significance of cross-wall formation remains largely unknown. Using genetics and quantitative imaging, the authors identified a previously uncharacterized protein, SepX, essential for cross-wall formation and for efficient sporulation septation. Deletion of sepX caused severe growth defects, demonstrating the necessity for vegetative division. These results provide a genetic basis for future research into the regulation of bacterial multicellular development, including how cross-walls form, how they relate to fitness, and how the two distinct cell types are coordinated.

Mitotic drive in asymmetric epigenetic inheritance.

Asymmetric cell division (ACD) produces two daughter cells with distinct cell fates. This division mode is widely used during development and by adult stem cells during tissue homeostasis and regeneration, which can be regulated by both extrinsic cues such as signaling molecules and intrinsic factors such as epigenetic information. While the DNA replication process ensures that the sequences of sister chromatids are identical, how epigenetic information is re-distributed during ACD has remained largely unclear in multicellular organisms. Studies of Drosophila male germline stem cells (GSCs) have revealed that sister chromatids incorporate pre-existing and newly synthesized histones differentially and segregate asymmetrically during ACD. To understand the underlying molecular mechanisms of this phenomenon, two key questions must be answered: first, how and when asymmetric histone information is established; and second, how epigenetically distinct sister chromatids are distinguished and segregated. Here, we discuss recent advances which help our understanding of this interesting and important cell division mode.

Abscisic acid switches cell division modes of asymmetric cell division and symmetric cell division in stem cells of protonemal filaments in the moss Physcomitrium patens.

Multicellular organisms regulate cell numbers and cell fate by using asymmetric cell division (ACD) and symmetric cell division (SCD) during their development and to adapt to unfavorable environmental conditions. A stem cell self-renews and generates differentiated cells. In plants, various types of cells are produced by ACD or SCD; however, the molecular mechanisms of ACD or SCD and the cell division mode switch are largely unknown. The moss Physcomitrium (Physcomitrella) patens is a suitable model to study plant stem cells due to its simple anatomy. Here, we report the cell division mode switch induced by abscisic acid (ABA) in P. patens. ABA is synthesized in response to abiotic stresses and induces round-shape cells, called brood cells, from cylindrical protonemal cells. Although two daughter cells with distinct sizes were produced by ACD in a protonemal stem cell on ABA-free media, the sizes of two daughter cells became similar with ABA treatment. Actin microfilaments were spatially localized on the apices of apical stem cells in protonemata on ABA-free media, but the polar accumulation was lost under the condition of ABA treatment. Moreover, ABA treatment conferred an identical cell fate to the daughter cells in terms of cell division activity. Collectively, the results indicate ABA may suppress the ACD characteristics but evoke SCD in cells. We also noticed that ABA-induced brood cells not only self-renewed but regenerated protonemal cells when ABA was removed from the media, suggesting that brood cells are novel stem cells that are induced by environmental signals in P. patens.

Comparative Transcriptome Analysis of Hard and Tender Fruit Spines of Cucumber to Identify Genes Involved in the Morphological Development of Fruit Spines.

The spines of cucumber fruit not only have important commercial value but are also a classical tissue to study cell division and differentiation modes of multicellular trichomes. It has been reported that CsTs (C-type Lectin receptor-like kinase) can influence the development of fruit spines. In this study, we took a pair of cucumber materials defined as hard (Ts, wild type) and tender spines (ts, mutant) and defined the developmental process of fruit spines as consisting of four stages (stage I to stage IV) by continuously observing by microscope and SEM. Comparisons of transcriptome profiles at different development stages of wild-type spines showed that 803 and 722 genes were upregulated in the stalk (stage II and stage III) and base (stage IV) development stages of fruit spines, respectively. The function analysis of DEGs showed that genes related to auxin polar transport and HD-ZIP transcription factor are significantly upregulated during the development of the stalk. bHLH transcription factors and cytoskeleton-related genes were significantly upregulated during the development of the base. In addition, stage III is the key point for the difference between wild-type and mutant spines. We detected 628 DEGs between wild type and mutant at stage III. These DEGs are mainly involved in the calcium signaling of the cytoskeleton and auxin polar transport. Coincidentally, we found that CsVTI11, a factor involved in auxin signal transmission, can interact with CsTs in vivo, but this interaction does not occur between CsVTI11 and Csts, further suggesting that CsTs may regulate the development of fruit spines by influencing cell polarity. These results provide useful tools to study the molecular networks associated with cucumber fruit spine development and elucidate the biological pathways that C-type Lectin receptor-like kinase plays in regulating the development of fruit spines.