Surface Layer Of Cells Research Articles

TREATMENT OF TROPHIC COMPLICATIONS IN DECOMPENSATED FORMS OF IMPAIRED ARTERIAL BLOOD CIRCULATION OF THE LOWER EXTREMITIES

Summary. The aim of the study was to study the clinical effectiveness of using the developed method of cryopreservation on wound surfaces using a cryopreservation device. Materials and methods. 87 patients with ulcerative-necrotic defects of the lower legs and feet were selected for the study. The condition for inclusion in the study was Phase I of the wound process. Patients were divided into the main and comparison groups. The main group included 41 patients who had their wounds cleaned according to the proposed method, and the comparison group consisted of 46 patients who underwent surgical treatment. Results. The use of cryodestruction of the surface of trophic ulcers of arterial etiology led to rapid cleaning of necrotic masses, fibrin, a decrease in exudation and pain intensity, and the disappearance of unpleasant odors. The effectiveness of the methods lies in the fact that not only necrotic components of the wound surface, fibrin films, as well as the surface layers of ulcer surface cells are destroyed, that is, phenotypically altered cells of the wound edge and base are removed, leading to a violation of regeneration processes. Conclusions. Debridment methods based on the use of controlled cryodestruction of pathological tissues on the surface of trophic ulcers accelerate the transition of the wound process to phase II by 25% in patients with trophic ulcers with critical ischemia of the lower extremities.

Wildebeest herds on rolling hills: Flocking on arbitrary curved surfaces.

The collective behavior of active agents, whether herds of wildebeest or microscopic actin filaments propelled by molecular motors, is an exciting frontier in biological and soft matter physics. Almost three decades ago, Toner and Tu developed a continuum theory of the collective action of flocks, or herds, that helped launch the modern field of active matter. One challenge faced when applying continuum active matter theories to living phenomena is the complex geometric structure of biological environments. Both macroscopic and microscopic herds move on asymmetric curved surfaces, like undulating grass plains or the surface layers of cells or embryos, which can render problems analytically intractable. In this paper, we present a formulation of the Toner-Tu flocking theory that uses the finite element method to solve the governing equationson arbitrary curved surfaces. First, we test the developed formalism and its numerical implementation in channel flow with scattering obstacles and on cylindrical and spherical surfaces, comparing our results to analytical solutions. We then progress to surfaces with arbitrary curvature, moving beyond previously accessible problems to explore herding behavior on a variety of landscapes. This approach allows the investigation of transients and dynamic solutions not revealed by analytic methods. It also enables versatile incorporation of new geometries and boundary conditions and efficient sweeps of parameter space. Looking forward, the paper presented here lays the groundwork for a dialogue between Toner-Tu theory and data on collective motion in biologically relevant geometries, from drone footage of migrating animal herds to movies of microscopic cytoskeletal flows within cells.

Investigation of Wall Shear Stress in Cardiovascular Research and in Clinical Practice-From Bench to Bedside.

In the 1900s, researchers established animal models experimentally to induce atherosclerosis by feeding them with a cholesterol-rich diet. It is now accepted that high circulating cholesterol is one of the main causes of atherosclerosis; however, plaque localization cannot be explained solely by hyperlipidemia. A tremendous amount of studies has demonstrated that hemodynamic forces modify endothelial athero-susceptibility phenotypes. Endothelial cells possess mechanosensors on the apical surface to detect a blood stream-induced force on the vessel wall, known as “wall shear stress (WSS)”, and induce cellular and molecular responses. Investigations to elucidate the mechanisms of this process are on-going: on the one hand, hemodynamics in complex vessel systems have been described in detail, owing to the recent progress in imaging and computational techniques. On the other hand, investigations using unique in vitro chamber systems with various flow applications have enhanced the understanding of WSS-induced changes in endothelial cell function and the involvement of the glycocalyx, the apical surface layer of endothelial cells, in this process. In the clinical setting, attempts have been made to measure WSS and/or glycocalyx degradation non-invasively, for the purpose of their diagnostic utilization. An increasing body of evidence shows that WSS, as well as serum glycocalyx components, can serve as a predicting factor for atherosclerosis development and, most importantly, for the rupture of plaques in patients with high risk of coronary heart disease.

Hemorrhagic Shock and Resuscitation Causes Glycocalyx Shedding and Endothelial Oxidative Stress Preferentially in the Lung and Intestinal Vasculature.

Hemorrhagic shock has recently been shown to cause shedding of a carbohydrate surface layer of endothelial cells known as the glycocalyx. This shedding of the glycocalyx is thought to be a mediator of the coagulopathy seen in trauma patients. Clinical studies have demonstrated increases in shed glycocalyx in the blood after trauma, and animal studies have measured glycocalyx disruption in blood vessels in the lung, skeletal muscle, and mesentery. However, no study has measured glycocalyx disruption across a wide range of vascular beds to quantify the primary locations of this shedding. In the present study, we used a rat model of hemorrhagic shock and resuscitation to more comprehensively assess glycocalyx disruption across a range of organs. Glycocalyx disruption was assessed by fluorescent-labeled wheat germ agglutinin or syndecan-1 antibody staining in flash frozen tissue. We found that our model did elicit glycocalyx shedding, as assessed by an increase in plasma syndecan-1 levels. In tissue sections, we found that the greatest glycocalyx disruption occurred in vessels in the lung and intestine. Shedding to a lesser extent was observed in vessels of the brain, heart, and skeletal muscle. Liver vessel glycocalyx was unaffected, and kidney vessels, including the glomerular capillaries, displayed an increase in glycocalyx. We also measured reactive oxygen species (ROS) in the endothelial cells from these organs, and found that the greatest increase in ROS occurred in the two beds with the greatest glycocalyx shedding, the lungs, and intestine. We also detected fibrin deposition in lung vessels following hemorrhage-resuscitation. We conclude that the endothelium in the lungs and intestine are particularly susceptible to the oxidative stress of hemorrhage-resuscitation, as well as the resulting glycocalyx disruption. Thus, these two vessel beds may be important drivers of coagulopathy in trauma patients.

A physico-chemical study of the interaction of ethanolic extracts of propolis with bacterial cells

In the present study, an effort has been made to understand the interaction mode of propolis, a natural substance produced by honey bees, with gram-positive and gram-negative bacterial cells by measuring alterations in cell surface physico-chemical properties following the incubation of the cells with different sub-inhibitory concentrations of this antimicrobial agent. Electrophoretic mobility and surface hydrophobicity measurements revealed for the first time that propolis induced substantial changes in the volumetric charge density, electrophoretic softness and degree of hydrophobicity characterizing the outermost surface layer of cells. These changes, which appear to be dose-dependent, seem to be consistent with the increasing accumulation and penetration of the propolis antimicrobial components through the cells extracellular layer. Moreover, electron microscopy observation and the determination of the cell constituents’ release demonstrated that propolis at sub-bactericidal concentrations already provoked (at least localized) cell wall damage and/or perturbations. These findings thus suggest that the initial mechanism of action of propolis is most likely structural, resulting from sufficient interaction between the different propolis components and bacterial cell wall structures.

Nonclassical Chiral Elasticity of the Gyroid Lattice.

The gyroid lattice is a metamaterial which allows chirality that is tunable by geometry.Gyroid lattices were made in chiral and nonchiral form by 3D printing. The chiral lattices exhibited nonclassical elastic effects including coupling between compressive stress and torsional deformation.Gyroid lattices can approach upper bounds on elastic modulus. Effective modulus is increased by distributed moments but is, for gyroid cylinders of sufficiently small radius, softened by a surface layer of incomplete cells. Such size dependence is similar to that in foams but is unlike most lattices.

Shelf-life extension of freeze-dried Lactobacillus brevis WiKim0069 using supercooling pretreatment

Shelf-life extension of freeze-dried lactic acid bacteria is important for reducing distribution costs. Herein, effect of cold adaptation prior to freeze drying on the storage stability of freeze-dried Lactobacillus brevis WiKim0069, a kimchi starter, was investigated under supercooling at −5 °C without ice crystal nucleation and formation. Cold adaptation at 10 °C was used as a reference. Cold adaptation caused an increase in surface layer protein and improved cell viability. The surface layer of cold-adapted cells was substantially thicker than that of non-adapted cells, with supercooling inducing the strongest effect. Cold adaptation increased the viability of L. brevis WiKim0069 during and after 56-day storage. After 56 days of storage, the highest viability of 81.2% was observed with supercooling pretreatment. The addition of surface layer protein during cold adaptation further promoted viability, supporting the role of surface layer protein. These results suggest that supercooling pretreatment can be useful for extending the shelf-life of L. brevis WiKim0069.

Penetration Efficiency of Antitumor Agents in Ovarian Cancer Spheroids: The Case of Recombinant Targeted Toxin DARPin-LoPE and the Chemotherapy Drug, Doxorubicin.

The efficiency of delivering a therapeutic agent into a tumor is among the crucial factors determining the prospects for its clinical use. This problem is particularly acute in the case of targeted antitumor agents since many of them are high-molecular-weight compounds. In this work, the penetration of therapeutic agents of two distinct molecular weights into the spheroids of ovarian adenocarcinoma overexpressing human epidermal growth factor receptor 2 (HER2) was studied. It was shown that the low-molecular-weight chemotherapy drug, doxorubicin (~0.5 kDa), effectively penetrates through almost the entire depth of a 300 to 400 μm spheroid, while the penetration depth of the HER2-specific recombinant targeted toxin, DARPin-LoPE (~42 kDa), is only a few surface layers of cells and does not exceed 70 μm. The low penetration of the targeted toxin into spheroid was shown along with a significant decrease in its efficiency against the three-dimensional tumor spheroid as compared with the two-dimensional monolayer culture. The approaches to increasing the accumulation of agents in the tumor are presented and prospects of their use in order to improve the effectiveness of therapy are discussed.

Distribution of the neuropeptide calcitonin gene-related peptide-α of tooth germ during formation of the mouse mandible

Calcitonin gene-related peptide-α (CGRPα) is a neurotransmitter that is related to bone formation during development. However, CGRP expression is not well known to affect the formation of teeth during development. During tooth germ development, the relationships among CGRPα, calcitonin receptor-like receptor (CRLR), amelogenin (AMELX), dentin sialophosphoprotein (DSPP), osteopontin (OPN) and osteocalcin (OCN) are unclear despite various tooth and osteogenesis markers. Our real-time RT-PCR results showed that the expression levels of CGRPα mRNA gradually decreased, in contrast to the mRNA abundances of CRLR, AMELX, DSPP, OPN, and OCN, which rapidly increased from E14.5 to P1 in the mandible. In situ hybridization using an antisense probe for CGRPα mRNA showed significant localized expression levels around the tooth bud at E14.5 and epithelial cells near the dental ledge and outer and inner enamel epithelium at E17.5 compared to those at P1. The localization of the anti-CGRPα antibody reaction revealed a strong positive reaction at the surface layer of oral epithelial cells at E14.5 and oral epithelial cells of the dental lamina around the dental ledge depression in the mandible of E17.5 mice using immunohistochemical methods The different anti-CGRPα reaction revealed its important roles during tooth formation at the postnatal stage. CGRPα mRNA was also detected in the interactions of tooth germ with the formation of odontoblast and amelobast layers from dental papilla and inner enamel epithelium. CGRPα may also be related to tooth germ development. Furthermore, CGRPα is an important tooth and bone formation marker, and bone cells provide further evidence of a role in mandibular development in contrast to inflammatory systems.

Cell therapy of a knee osteoarthritis rat model using precartilaginous stem cells.

To explore the effect and mechanism of precartilaginous stem cells (PSCs) engraftment-inducing tissue repair in a knee osteoarthritis (OA) rat model. Knee osteoarthritis (OA) model was constructed in Sprague Dawley (SD) rats by partial removal of the medial meniscus of the right knee. PSCs were engrafted by injecting precartilaginous stem cells (PSCs) into the right knee cavity. At 4 and 8 weeks after model construction, the serum levels of interleukine (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 were assessed using enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was performed to assess the histopathology of synovial membrane and cartilage. Western blot analysis was used to assess Notch1, Bcl-2 and Bax levels in the articular cartilage. At 4 and 8 weeks, OA rats demonstrated significantly higher IL-1β, TNF-α, and IL-6 levels than normal rats (p < 0.05), whereas PSCs treatment prominently attenuated IL-1β upregulation (p < 0.05). In OA rats, the number of chondrocytes dramatically decreased over time in OA rats, with disruption of chondrocytes organization and cell layers. PSCs alleviated the deterioration of cartilage, as evidenced by the relatively smooth articular surface, distinct tidemark and clear cell layers. The model and treatment groups demonstrated substantially higher Notch1 expression. The Bcl-2/Bax value in the OA rats was lower than the control group, while PSCs treatment led to increase in Bcl-2/Bax value. PSCs treatment downregulated the expression of inflammatory cytokines, alleviating osteoarthritis in the knee of rats. Notch1 signaling pathway plays an important role in this ameliorating effect of PSCs treatment.

MiRNAs control HAM1 functions at the single-cell-layer level and are essential for normal embryogenesis in Arabidopsis.

KEY MESSAGE: miR171a controls HAM1 functions within the protodermal cells of the embryo, and these controls are essential for normal embryogenesis in Arabidopsis. Arabidopsis thaliana miR171a is known to bind to and cleave mRNAs of three HAIRY MERISTEM (HAM) genes that encode members of the GRAS family transcriptional regulators. The molecular functions of the HAM genes are still being elucidated in Arabidopsis. However, detailed expression patterns of miR171a and the effects of the failure of miR171a to suppress HAM genes were unknown till now. Here, we show the detailed expression patterns of miR171a and HAM1 using green fluorescent protein and confocal scanning microscopy. Our observations revealed that miR171a was expressed in the surface cell layer of the embryo and shoot apical meristem, and it controlled HAM1 functions. To determine the impact of the failure of miR171a to suppress of HAM1, we introduced seven synonymous mutations into the miR171a target site of the HAM1 gene (modified HAM1, mHAM1) and generated transgenic plants that had mHAM1 driven by HAM1 native promoter. The mHAM1 transgenic plants showed organogenic defects. These results indicate that the control of HAM1 functions at the single-cell-layer level by miR171a is essential for proper organ formation in Arabidopsis.

Analysis and modeling of the inverted bioconvection in Chlamydomonas reinhardtii: emergence of plumes from the layer of accumulated cells

Bioconvection is a convective flow found in a suspension of motile cells that swim against gravity, and is a primitive form of order formation of cells, which has been studied both experimentally and theoretically. We formulate here an inverted bioconvection occurring in a suspension of phototactic cells in a high-density medium, which is illuminated from the bottom. We used a highly phototactic strain 137c of Chlamydomonas reinhardtii in the experiments. Using a custom-made lateral microscope, we observed a close view of cellular dynamics in the initiation of inverted bioconvection. In conventional bioconvection, convective flows of cells are formed spontaneously with or without formation of the surface cell layer. In inverted convection, a crowded cell layer was initially formed at the bottom, which was a prerequisite for the subsequent emergence of plumes, namely, floating populations of cells. The plume formation was a result of neither uneven initial cell density nor unequal light intensity. Based on detailed analysis of individual cells, we constructed a model of inverted bioconvection, in which each cell experiences a transition between two modes of movement: phototactically swimming cell and non-motile cell aggregate. A simulation using the CompuCell3D software reproduced basic behaviors of the plume formation. The modal transition has not been a subject of basic studies, but provides an interesting target of study of cell-to-cell interactions.

A method to generate the surface cell layer of the 3D virtual shoot apex from apical initials

BackgroundThe development of cell pattern in the surface cell layer of the shoot apex can be investigated in vivo by use of a time-lapse confocal images, showing naked meristem in 3D in successive times. However, how this layer is originated from apical initials and develops as a result of growth and divisions of their descendants, remains unknown. This is an open area for computer modelling. A method to generate the surface cell layer is presented on the example of the 3D paraboloidal shoot apical dome. In the used model the layer originates from three apical initials that meet at the dome summit and develops through growth and cell divisions under the isotropic surface growth, defined by the growth tensor. The cells, which are described by polyhedrons, divide anticlinally with the smallest division plane that passes depending on the used mode through the cell center, or the point found randomly near this center. The formation of the surface cell pattern is described with the attention being paid to activity of the apical initials and fates of their descendants.ResultsThe computer generated surface layer that included about 350 cells required about 1200 divisions of the apical initials and their derivatives. The derivatives were arranged into three more or less equal clonal sectors composed of cellular clones at different age. Each apical initial renewed itself 7–8 times to produce the sector. In the shape and location and the cellular clones the following divisions of the initial were manifested. The application of the random factor resulted in more realistic cell pattern in comparison to the pure mode. The cell divisions were analyzed statistically on the top view. When all of the division walls were considered, their angular distribution was uniform, whereas in the distribution that was limited to apical initials only, some preferences related to their arrangement at the dome summit were observed.ConclusionsThe realistic surface cell pattern was obtained. The present method is a useful tool to generate surface cell layer, study activity of initial cells and their derivatives, and how cell expansion and division are coordinated during growth. We expect its further application to clarify the question of a number and permanence or impermanence of initial cells, and possible relationship between their shape and oriented divisions, both on the ground of the growth tensor approach.

Effects of Plasma Enhanced Chemical Vapor Deposition Radio Frequency on the Properties of SiNx:H Films

Hydrogenated silicon nitride (SiNx:H) films were fabricated using plasma-enhanced chemical vapor deposition at high (13.56 MHz), low (400 kHz), and dual (13.56 MHz + 400 kHz) radio frequencies. The antireflection and passivation qualities of each film were investigated before their application as the front surface layer of crystalline silicon solar cells. The use of a high radio frequency was observed to have a positive effect on the cell performance, which increased by 0.4% in comparison with the minimum value obtained for a 156 mm × 156 mm cell.

The Physical Basis of Coordinated Tissue Spreading in Zebrafish Gastrulation

SummaryEmbryo morphogenesis relies on highly coordinated movements of different tissues. However, remarkably little is known about how tissues coordinate their movements to shape the embryo. In zebrafish embryogenesis, coordinated tissue movements first become apparent during “doming,” when the blastoderm begins to spread over the yolk sac, a process involving coordinated epithelial surface cell layer expansion and mesenchymal deep cell intercalations. Here, we find that active surface cell expansion represents the key process coordinating tissue movements during doming. By using a combination of theory and experiments, we show that epithelial surface cells not only trigger blastoderm expansion by reducing tissue surface tension, but also drive blastoderm thinning by inducing tissue contraction through radial deep cell intercalations. Thus, coordinated tissue expansion and thinning during doming relies on surface cells simultaneously controlling tissue surface tension and radial tissue contraction.

Micro-Morphological investigation of the Skin of the Larval and Adult Stages of the African Catfish (Clarias gariepinus)

The current study aimed to explore the skin sructure at the larval and adult stages of the African catfish. Of the previous studies on the skin morphology of fish, none has researched the detailed skin differentiation at the larval and adult stages of the African catfish. Here by light microscopic investigation, the skin of the larva after hatching consisted of two layers of simple squamous epithelium. The skin of the 5-6 day old larva consisted of more than one layer of flattened to oval cells, continuous layer of melanocytes and club cells showed up. The skin of the 15-days old larva distinguished into epidermis, dermis and hypodermis. While the skin of the adult catfish, the epidermis consisted of three layers a basal layer of cuboidal or columnar cells, middle layer of polyhedral cells and surface layer of flattened cells. Its mucous cells were oval in shape having foamy cytoplasm. Its club cells had acidophilic cytoplasm and some cells were binucleated. At the lateral line, a group of elongated neuromasts viewed between the club cells. Langerhans like cell showed a positive reaction with CD 1a. The dermis divided into stratum spongiusm and stratum compactum. At lateral line beneath the hypodermis, the neuromast canal detected. By SEM, no any evidence of taste buds pores and neuromast detected at the newly hatched larva. Different forms of neuromast appeared on the surface as small epidermal protrusions at the 6-day old larva. In addition, the neuromast at the epidermal protrusion appeared with long and short hair bundles. While, the skin the adult catfish, the surface epithelium showed many projections, the broken epidermis showed a large club cells, melanocytes with cytoplasmic processes and pores. By TEM of the adult catfish, the surface cells had (microridges), desmosomes distinguished between the neighboring epidermal surface cells. The club cells cytoplasm had scanty organelles, two types of club cells identified; the first type with no vesicular secretion and the second type with fibrillar cytoplasm. The plasma membrane showed many invaginations. The study recorded two types of neuromast; superficial neuromast and canal neuromast set in the dermis. No neurmast detected at the 1st day larva afterthat it appeared and incresead in number and its shape changed from simillar hair cells to long and short hair bundles.

The Repetitive Detection of Toluene with Bioluminescence Bioreporter Pseudomonas putida TVA8 Encapsulated in Silica Hydrogel on an Optical Fiber.

Living cells of the lux-based bioluminescent bioreporter Pseudomonas putida TVA8 were encapsulated in a silica hydrogel attached to the distal wider end of a tapered quartz fiber. Bioluminescence of immobilized cells was induced with toluene at high (26.5 mg/L) and low (5.3 mg/L) concentrations. Initial bioluminescence maxima were achieved after >12 h. One week after immobilization, a biofilm-like layer of cells had formed on the surface of the silica gel. This resulted in shorter response times and more intensive bioluminescence maxima that appeared as rapidly as 2 h after toluene induction. Considerable second bioluminescence maxima were observed after inductions with 26.5 mg toluene/L. The second and third week after immobilization the biosensor repetitively and semiquantitatively detected toluene in buffered medium. Due to silica gel dissolution and biofilm detachment, the bioluminescent signal was decreasing 20–32 days after immobilization and completely extinguished after 32 days. The reproducible formation of a surface cell layer on the wider end of the tapered optical fiber can be translated to various whole cell bioluminescent biosensor devices and may serve as a platform for in-situ sensors.

Wound‐healing potential of curcumin in the carp, L abeo rohita

In this investigation, the effect of dietary administration of curcumin on the healing of skin wound in fish, Labeo rohita, has been reported. Fish were divided into three groups: control group (fish without skin wound), sham group (fish with skin wound without curcumin treatment) and curcumin-treated group (fish with skin wound and subjected to dietary administration of 1% curcumin). Experiments were conducted for 30 days to assess the healing of skin wounds at different time intervals using scanning electron microscopy, histology, and mucopolysaccharide and enzyme histochemistry. In the curcumin-treated group, healing of skin wounds was found to be enhanced than in the sham group as indicated by early restoration of morphology of the surface layer of epithelial cells; the density of the mucous goblet cells; the density of club cells in epidermal layer; and early granular tissue formation, collagen deposition and tissue remodelling in dermal layer. Furthermore, peroxidase and catalase enzyme activity showed increased endogenous defence system in the curcumin-treated group compared with the sham group. It could be concluded that dietary administration of curcumin is beneficial in rapid healing of skin wounds in fish. Early healing of wounds could be considered to prevent the invasion of pathogens and to maintain the integrity of the surrounding tissue.

The Interaction between Endophytic Actinomycetes and Rhizobium in Leguminous Plants

Biological N2 fixation represents the major source of N input in many agricultural soils including those in arid regions where little artificial fertilizer is applied. The major N2-fixing systems in agriculture are the symbiotic systems, where bacteria such as rhizobia interact with legumes to fix atmospheric nitrogen which plays a significant role in improving the fertility and productivity of low-N soils. The symbiotic association of legume-rhizobium is initiated by the colonization of the rhizosphere by the rhizobia and subsequent attachment to the root hairs of the host plant. Furthermore, the host will produce flavonoids, such as luteolin in alfalfa and diazedin in soybean, which interact with nod protein in the rhizobia. Moreover, this process then elicits the expression of a cluster of nodulation genes such as nod, nol, and noe in the rhizobia. The interaction is potentially of great importance to the health and growth in nature of this nodulating legume.The interaction between endophytic Actinomycetes and rhizobia in leguminous plants is one way to improve the capability of leguminous plants to fix atmospheric nitrogen in plant roots and contribute to the plants nutrition. From other studies, we know that certain types of Actinomycetes, for example Streptomyces, interact with peas to form healthy roots as an effective site to form nodules and improve biological nitrogen fixation. Knowledge about this activity against fungal pathogens might lead to finding biocontrol agents for use in sustainable agricultural practices.Root-colonizing soil borne Actinomycetes might influence root nodulation in leguminous plants by increasing root nodulation frequency, possibly at the sites of infection by Rhizobium spp. Actinomycetes also colonize and sporulate within the surface cell layers of the nodules. This colonization leads to an increase in the average size of the nodules that form and improves the vigor of the bacteroids which generate the red color within the nodules by enhancing nodular assimilation of iron and possibly other soil nutrients. Keywords: symbiotic, biological, nitrogen, molecular interaction

The fate of surface cell layers of Daucus carota (L.) embryos raised in suspension culture

The ultrastructure and fate of surface cells covering mature somatic embryos of Daucus carota grown in suspension culture were analyzed and new information obtained concerning somatic embryogenesis in these conditions. Our studies showed that during some developmental stages, these embryos were covered irregularly and discontinuously by cells with a typical protodermal phenotype characterized by a cuticle on the outer cell wall. We observed that cells with cuticles were peeled off from the surface of mature embryos. Before peeling off, these cells underwent programmed cell death, which was confirmed by the TdT-mediated dUTP nick end labeling method. Transmission electron microscopy revealed advanced processes of autophagy in these cells.