SEARCH · Search PubMed

Results for “Lectins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources

PubMed2001

Classification of plant lectins in families of structurally and evolutionary related proteins.

The majority of plant lectins can be classified in seven families of structurally and evolutionary related proteins. Within a given lectin family most but not necessarily all members are built up of protomers with a similar primary structure and overall 3-D fold. The overall structure of the native lectins is not only determined by the structure of the protomers but depends also on the degree of oligomerization and in some cases on the post-translational processing of the lectin precursors. In general, lectin families are fairly homogeneous for what concerns the overall specificity of the individual lectins, which illustrates that the 3-D structure of the binding site has been conserved during evolution. In the case of the jacalin-related lectins the occurrence of a mannose- and galactose-binding subfamily can be explained by the fact that a post-translational cleavage of the protomers (of the galactose-binding subfamily) yields a slightly altered binding site. Unlike the other families, the legume lectins display a wide range of specificites, which is clearly reflected in the occurrence of sugar-binding sites with a different 3-D structure.

Carbohydrate Metabolism↗

PubMed2001

Expression of binding properties of Gal/GalNAc reactive lectins by mammalian glycotopes (an updated report).

Expression of the binding properties of Gal/GalNAc specific lectins, based on the affinity of decreasing order of mammalian glycotopes (determinants) rather than monosaccharide inhibition pattern, is probably one of the best ways to express carbohydrate specifity and should facilitate the selection of lectins as structural probes for studying mammalian glycobiology. Eleven mammalian structural units have been selected to express the binding domain of applied lectins. They are: 1. F, GalNAcalpha1 --> 3GalNAc; 2. A, GalNAcalpha1 --> 3Gal; 3. T, Galbeta1 --> 3GalNAc; 4. I, Galbeta 1 --> 3GlcNAc; 5. II, Galbeta1 --> 4GlcNAc; 6. B, Galalpha1 --> 3Gal; 7. E, Galalpha1--> 4Gal; 8. L, Galbeta1 --> 4Glc; 9. P, GalNAcbeta1 --> 3Gal; 10. S, GalNAcbeta1 --> 4Gal and 11. Tn, GalNAcalpha1 --> 4Ser (Thr) of the peptide chain. Thus, the carbohydrate specificity of Gal/GalNAc reactive lectins can be divided into classes according to their highest affinity for the above disaccharides and/or Tn residue. Examples of the binding properties of these lectins can be demonstrated by Ricimus communis agglutinin (RCA1), grouped as II specific lectin and its binding property is II > I > B > T; Ahrus precatorius agglutinin (APA), classified as T and its carbohydrate specificity is T > I/II > E > B > Tn; Artocarpus integrifolia (jacalin, AIL), as T/Tn specific and its binding reactivity is T > Tn >> I (II) and Geodia cydonium (GCL), as F/A specific, and with affinity for F > Ah [GalNAcalpha1-->43(L(Fuc)alpha1-->2)Gal] >> I > L. Due to the multiple reactivity of lectins toward mammalian glycotopes, the possible existence of different combining sites or subsites in the same molecule has to be examined, and the differential binding properties of these combining sites (if any) have to be characterized. To establish the relationship among the amino acid sequences of the combining sites of plant lectins and mammalian glycotopes should be an important direction to be addressed in lectinology.

Acetylgalactosamine↗

PubMed1986

Lectin cytochemical evaluation of somatosensory neurons and their peripheral and central processes in rat and man.

Paraffin sections of the trigeminal nerve root of the rat, and human spinal nerve root and trigeminal ganglion were stained with a battery of lectin-horseradish peroxidase conjugates to localize and characterize glycoconjugate (GC) in situ. In the rat the myelin sheath of the peripheral segment contained GC with sialic acid most probably linked to the penultinate disaccharide galactose-(beta 1----4)-N-acetylglucosamine (Gal(beta 1----)-GlcNAc), and complex type N-glycosidic side chains. The myelin sheath in the central segment differed in containing little if any of the GC named above and in containing GC with terminal beta-Gal linked to N-acetylgalactosamine (GalNAc), terminal GalNAc and fucose. Schwann cells stained for GC with GlcNAc or mannose whereas oligodendroglia stained for GC with the terminal disaccharide Gal-(beta 1----3)-GalNAc and N-glycosidic side chains, especially in presumed Golgi zones, but also in processes continued as the outer myelin sheath. The human myelin sheath in the central segment differed from that of the rat in not staining with lectins specific for fucose and terminal GalNAc. Sialic acid and terminal beta-Gal were seen in the human central segment but these sugars appeared to bind to astroglial structures rather than to the myelin sheath as in the rat. Astrocytes in both rat and man were stained by two fucose-binding lectins. Several lectins revealed affinity for GC in the neurilemmal sheath, and staining of this structure was stronger in the human specimens. Neurons in the human trigeminal ganglion ranged from unstained to strongly positive for fucoconjugate in cytoplasmic bodies and plasmalemma. Positive ganglion cells gave rise to unmyelinated fibers which also stained for fucoconjugate. Remak fibers and their extensions into the substantia gelatinosa of the human spinal cord stained strongly for content of fucose. The stronger lectin affinity for N-glycosidic core sugars in the peripheral as compared with the central segment suggests that lectins localize Po protein in peripheral myelin. The reactivity for several sugars in the central segment can possibly be attributed to myelin-associated glycoprotein (MAG) of central myelin, but lectin staining for GalNAc shows in addition a biochemically unrecognized GC with O-glycosidic linked oligosaccharides in myelin. The lectin cytochemistry indicates that the 170 K Dalton glycoprotein with PNA affinity obtained from rat sciatic nerves occurs in nodes of Ranvier.

Adult↗

PubMed1990

Secretory glycoconjugates of a mucin-synthesizing human colonic adenocarcinoma cell line. Analysis using double labeling with lectins.

Lectins were used to characterize mucin glycoproteins and other secretory glycoconjugates synthesized by a human colon adenocarcinoma-derived cell line which expresses a goblet cell phenotype. Despite being clonally derived, HT29-18N2 (N2) cells, like normal goblet cells in situ were heterogeneous in their glycosylation of mucin. Only wheat-germ agglutinin, which recognizes N-acetylglucosamine and sialic acid residues, and succinylated wheatgerm agglutinin, which binds N-acetylglucosamine, stained the contents of all secretory granules in all N2 goblet cells. The N-acetylgalactosamine binding lectins Dolichos biflorus and Glycine max stained 20% and 21% of N2 goblet cells respectively. Ricinus communis I, a galactose-binding lectin, stained 67% of N2 goblet cells although staining by another galactose-binding lectin, Bandeiraea simplicifolia I, was limited to 19%. Peanut agglutinin, a lectin whose Gal(beta 1-3)GalNAc binding site is not present on mucins produced in the normal colon but which is found on most mucins of cancerous colonic epithelia, stained 68% of the cells. Ulex europeus I, a fucose-binding lectin, did not stain any N2 goblet cells. Four lectins (Lens culinaris, Pisum sativum, Phaseolus vulgaris E, Phaseolus vulgaris L) which recognize sugars normally present only in N-linked oligosaccharides stained up to 38% of N2 goblet cells. The binding of these lectins indicates either both O-linked and N-linked oligosaccharide chains are present on the mucin protein backbone or the co-existence of non-mucin N-linked glycoproteins and O-linked mucins within the goblet cell secretory granule.

Adenocarcinoma↗

PubMed1992

Lectin binding sites on head structures of the spermatid and spermatozoon of the mosquito Culex quinquefasciatus (Diptera, Culicidae).

The presence of intranuclear and acrosomal lectin binding sites in spermatids and spermatozoa of the mosquito Culex quinquefasciatus was analysed. Direct and indirect lectin-gold techniques were used on LR White-embedded cells. The nuclear compartment was the structure most intensely labelled. Early spermatid nucleus showed moderate labelling for peanut agglutinin (PNA), Griffonia simplicifolia IB4 (GS-IB4) and Ricinus communis agglutinin (RCA), and light labelling for the other lectins tested. The sperm nucleus was intensely labelled by all lectins. The acrosome, an enzyme-containing structure, was labelled by some lectins. The anterior acrosomal region was labelled by PNA, while the proximal acrosomal region was labelled by PNA and G. simplicifolia II (GS II) lectins, and showed the presence of fucose residues with the use of Ulex europaeus I (UEA-I) lectin. The spermatozoa stored in the spermatheca showed the same pattern of labelling as that observed in spermatozoa localized in testis and seminal vesicles for all lectins tested. Carbohydrate residues in the nuclear compartment may be involved with the process of chromatin condensation. In the acrosomal region these residues may play a role in the process of sperm-oocyte interaction.

Acrosome↗

PubMed1985

The use of lectins to study normal differentiation and malignant transformation.

Lectins are polypeptides that specifically recognize carbohydrate residues of glycoproteins and glycolipids. They can be extracted from plants, invertebrates and vertebrates. The binding between lectins and carbohydrate moieties can be blocked by the inhibitory sugar for which the lectin is specific. In analogy to antibodies, lectins can be used to analyse cell surface determinants. Thus, differentiation of cells, in particular of immunocytes, has been studied and lectin receptors are now important markers for distinguishing different developmental stages of T-lymphocytes. In consequence, premature, but already committed, T-cells can be eliminated from human bone marrow by means of lectins prior to transplantation in order to avoid graft-versus-host reactions. Moreover, it has been shown that malignant cells can be distinguished from their non-malignant counterparts by the profile of lectin receptors on their surface. This had led to the use of lectin binding sites as tumour markers in lymphomas and carcinomas.

Animals↗

PubMed1987

The use of avidin-gold complex for light microscopic localization of lectin receptors.

In the present study, we have investigated the use of avidin-gold complex (AG) as a possible cytochemical marker for visualizing and identifying lectin receptors in deparaffinized tissue sections. Monodispersed gold sols of 15 nm average diameter were prepared by sodium citrate reduction. The AG complex was prepared with highly purified egg-white avidin (avidin-D). Deparaffinized sections of cat duodenum were labeled with five different biotinylated lectins, then were washed and stained for 1-2 h with AG. Intensification of the gold staining was achieved by a modification of the silver-enhancement method. For each lectin, the labeling properties of the avidin-gold-silver (AGS) were compared with those of the avidin-biotin-peroxidase (ABC) and the lectin-gold (LG) methods. We found the lectin binding pattern demonstrated by the AG method to be similar to that of the ABC. The AG localization of the carbohydrate residues is more precise, compared to the peroxidase reaction due to lack of diffusion of the gold marker. Labeling with AGS resulted in improved staining over the AG method, similar to the staining intensity of the ABC. In addition, the two-step AG method provided more intense staining than the direct one-step procedure of the lectin-gold labeling. In conclusion, the use of the AGS method for histochemical visualization of lectin receptors requires a simple two-step procedure which allows highly accurate localization of tissue glycoconjugates. It entails using only a single gold-ligand complex applicable to any biotinylated lectin regardless of its biochemical nature.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1982

The cellular specificity of lectin binding in the kidney. I. A light microscopical study in the rat.

In order to estimate the usefulness of lectins in the study of the functional segmentation of the nephron, the sites of binding of five lectins were identified in the rat kidney. Lectin-peroxidase conjugates were applied to cryostat sections. The bound conjugates were stained with 3,3'-diaminobenzidine for light microscopical observation. Each lectin has a specific binding pattern along the nephron. Reversely, the different segments of the nephron defined by other histological methods can be identified on the basis of their affinity for lectins. The different parts of the thick ascending limb, namely the medullary segment, the cortical segment and the macula densa, can be distinguished even more readily with lectin histochemistry than with any other histochemical procedure. The binding of lectins to luminal membranes in some segments indicate the possibility to use lectins for the separation of particular cell types and for the modification of the transport properties of their membranes.

Animals↗

PubMed1995

Differential response of the epidermal growth factor receptor tyrosine kinase activity to several plant and mammalian lectins.

Biosignalling via lectins may involve modulation of protein kinase activities. This aspect of the biological action of mammalian and plant lectins has been investigated for their effect on the activity of the isolated epidermal growth factor receptor (EGFR). The constitutive tyrosine kinase activity of the epidermal growth factor receptor from rat liver, isolated by calmodulin-affinity chromatography, was activated by concanvalin A (ConA), and wheat germ agglutinin (WGA) to a similar extent as the measured enhancement induced by EGF. In contrast, two mannose-specific lectins, the mannan-binding protein (MBP) and serum amyloid P component (SAP), isolated from human serum, have inhibitory effects, both in the absence and presence of EGF. The differential effects of these lectins were tested using as phosphorylatable substrates a co-polymer of glutamic acid-tyrosine, as well as calmodulin. However, two galactoside-specific lectins, the laminin-binding beta-galactoside-binding 14 kDa lectin, isolated from bovine heart (14K-BHL), and the alpha/beta-galactoside-binding lectin, isolated from mistletoe (Viscum album L.) leaves (VAA), do not inhibit the EGFR tyrosine kinase activity. The sugar dependence of the lectin-mediated action was studied by inhibition assays. Mannose and a mannose-containing neoglycoprotein prevent the activating effect of ConA, and N-acetyl-D-glucosamine partially prevents the activation produced by WGA. However, mannose and mannose-containing neoglycoprotein were ineffective to reduce the inhibitory effect of MBP or SAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosamine↗

PubMed1989

Studies of lectin binding to the human cervix uteri: II. Cervical intraepithelial neoplasia and invasive squamous carcinoma.

The cell surface carbohydrate profile of formalin-fixed paraffin-embedded tissue sections of neoplastic cervical squamous epithelium was evaluated using lectins of Bauhinia purpurea (BPA), Canavalin ensiformis (Con A), Griffonia simplicifolia I (GS I), Griffonia simplicifolia II (GS II), Maclura pomifera (MPA), Archis hypogaea (PNA), Glycine max (SBA), Ulex europaeus I (UEA I) and Triticum vulgaris (WGA). Three lectins (BPA, Con A and PNA) showed a similar pattern of staining in both normal squamous epithelium and in cervical intraepithelial neoplasia (CIN). Variable alterations were seen in lectin-binding patterns in CIN with seven lectins (GS I, GS II, MPA, PNA, SBA, UEA I and WGA). A significant difference was seen between the intensity of staining of normal squamous epithelium and CIN with all lectins except WGA. The alteration in GS II-binding pattern and intensity was significantly related to grade of CIN. No correlation was found between lectin binding and the presence of koilocytes in squamous epithelium. Cases of invasive squamous carcinoma showed a heterogeneous lectin-binding pattern and no significant association was found between lectin binding and tumour differentiation of patient survival. These results indicate that neoplasia in cervical squamous epithelium is associated with alterations in terminal alpha-Man residues, alpha- and beta-GalNAc residues, alpha- and beta-GlcNAc residues, alpha- and beta-Gal residues, and alpha-Fuc-containing residues, present in the outer parts of both N-linked and O-linked glycoconjugates. The implications of these findings are discussed.

Carbohydrates↗

PubMed2003

Lectin histochemistry of the lymphoid organs of the chicken.

Cellular interactions within the immune system are in part mediated via the carbohydrate-rich coat of the cell membrane, the glycocalyx, of which the terminal carbohydrate residues are of particular functional importance. Thus, these carbohydrate residues from thymus, bursa of Fabricius, spleen and bone marrow of 2- and 30-day-old chickens were investigated by lectin histochemistry. In the thymus, mannose as well as N-acetyl-glucosamine (glcNAc)-specific lectins labelled macrophages, epithelial reticulum cells and lymphocytes within the cortex. In the bursa of Fabricius, the brush border of the lining epithelium, the macrophages and the endothelium were labelled by mannose-specific lectins. The follicle-associated epithelium was labelled by a broad spectrum of lectins. Epithelial cells that separated the cortex from the medulla and large mononuclear cells in the cortex were only being labelled by N-acetyl-galactosamine (galNAc)-specific and glcNAc-specific lectins, respectively. In the spleen, lymphocytes of the peri-ellipsoid lymphocyte sheaths and macrophages of the red pulp were labelled by lectins of nearly all sugar specificities. In general, glycotopes of these organs were more intensively labelled in the 2-day-old chicken than in the 30-day-old chicken, indicating changes in glycotope expression during post-hatching development. Thus, cells of the avian immune system are as rich and diverse in their lectin binding sites as their mammalian counterparts, indicating that similar carbohydrate lectin interactions between cells and matrices take place in birds as well.

Acetylglucosamine↗

PubMed2004

The in vivo synthesis and accumulation of lectin in developing seeds of black gram (Vigna mungo L. Hepper).

Black gram (Vigna mungo L. Hepper) seed contains two D-galactose-specific lectin species, BGL-I and BGL-II, identified on the basis of elution from ion exchange column and immunochemical cross-reactivity. BGL-I consisted of two monomeric lectins, BGL-I-1 and BGL-1-2, of relative molecular weights 94 and 89 kDa, respectively. BGL-II is another monomeric lectin with a molecular weight of 83 kDa. The in vivo synthesis studies using pulse-chase experiment showed that BGL-II lectin was synthesized as early as 14 days after flowering (DAF). The 94-kDa BGL-I-1 lectin was synthesized around 17 DAF. There was no cotranslational or posttranslational modification of the lectin proteins. The amount of lectin in developing seeds was determined by radial immunodiffusion assay technique. The maximum amount of lectin per seed was found at 28 DAF.

Food Analysis↗

PubMed1984

A solid-phase radio-binding assay for the characterization of lectin recognition.

A rapid and quantitative method for characterizing lectin specificity is presented. This assay is analogous to solid-phase radioimmune assays and utilizes the property of irreversible binding of proteins to vinyl microtiter plates. The lectins phytohemagglutinin and concanavalin A bind to vinyl and retain their biological properties. Iodinated fetuin and immunoglobulin G are both bound by the immobilized lectins. Competing amounts of ligands presented at the same time as the iodinated glycoproteins are shown to reduce binding to the immobilized lectins. Conversely, glycoprotein ligands immobilized to vinyl retain their ability to be recognized and bind lectins. The solid-phase binding assay can be used to characterize the ligand-binding specificity of lectins. For example, the pattern of glycoprotein inhibition of the binding of iodinated gorgonian lectin from Leptogorgia virgulata to insolubilized thyroglobulin is virtually identical to the pattern reported previously using hemagglutination inhibition. The solid-phase radio-binding assay is rapid, reproducible, and sensitive to nanogram quantities of ligand added. Most importantly, it provides quantitative information on lectin recognition.

Animals↗

PubMed1989

Neoglycoenzymes: a versatile tool for lectin detection in solid-phase assays and glycohistochemistry.

Carbodiimide-mediated coupling of p-aminophenyl glycosides to a naturally nonglycosylated enzyme yields a neoglycoenzyme. This compound combines inherent enzymatic activity with synthetically conferred ligand properties to lectins. Appropriate choice of the ligand allows custom-made synthesis to reliably detect various types of lectins. To exemplify practical applications of this class of compounds, glycosylated bacterial beta-galactosidase has been employed to quantitate plant lectins, immobilized on plastic surfaces as well as on nitrocellulose. Competitive inhibition by specific sugar ascertained the dependence of binding on protein--carbohydrate interactions. In view of lectins as tools, a sandwich lectin-binding assay for high mannose-type glycoprotein detection has been modified to principally facilitate wide application to other lectin-reactive sugar chains by introducing the neoglycoenzyme. In addition to lectin determination in solid-phase assays, neoglycoenzymes allow one to glycohistochemically localize endogenous lectins in tissue prints and tissue sections with a minimum number of steps. This nonradioactive, rapid, sensitive, and convenient assay concept, based on conjugation of a ligand to an enzyme with maintenance of its receptor-binding activity, may find extended application beyond lectinology in receptor analysis.

Biotin↗

PubMed1990

Biotinylated derivative of a human brain lectin: synthesis and use in affinoblotting for endogenous ligand studies.

Coupling of biotin to an endogenous lectin yields a probe which can be used for selective nonradioactive detection of complementary endogenous ligands. To exemplify practical applications of this type of compounds, we have synthesized and characterized a biotinylated derivative of a beta-galactoside-specific human brain lectin. Proteins which bind this lectin can be located on nitrocellulose sheets after electrophoretic transfer from gradient polyacrylamide gels, by sequential incubation with biotinylated probes and streptavidin-peroxidase, with visualization by an insoluble reaction product (affinoblotting). Biotinylated galactoside-binding plant lectins were used in the same way to visualize human brain glycoproteins, and their binding specificity was compared with that of human brain lectin. The results obtained by means of these different probes showed the usefulness of the endogenous lectin derivative to actually identify its endogenous partners. Thus this approach may find extended applications in the study of biological activities of vertebrate lectins in homologous systems, i.e., with lectins and ligands coming from the same tissue origin.

Amides↗

PubMed1984

Freeze-etch study of an unmodified lectin interacting with its receptors in model membranes.

Experiments are described in which liposomes bearing ganglioside or glycophorin as receptor were exposed to the native (unmodified) lectin, wheat germ agglutinin, and subsequently examined by freeze-etch electron microscopy. Visualized in this way in the absence of lectin, phosphatidylcholine bilayer membranes show no features attributable to the presence of small amounts of glycolipid. Similarly bilayers bearing glycophorin show no obvious etch face (outer surface) features attributable to that species, although they do have intramembranous particles associated with the hydrophobic interior. However, the otherwise smooth and featureless model membrane outer surface permitted ready visualization of bound lectin molecules, and thus the indirect localization of receptors. The lipid membrane itself in the vicinity of receptors was not visibly affected by lectin binding to glycolipid or glycoprotein. The only identifiable lectin-induced change was lateral redistribution of receptor glycoproteins. Ganglioside molecules showed some evidence of existing in small clusters; but their distribution was apparently unaffected by lectin binding. Clumps of lectin bound to glycophorin were found associated predominantly with fluid bilayer regions of phase separated membranes; and lectin distribution on the etch face correlated with intramembranous particle distribution in the fracture face. In contrast, ganglioside lateral distribution was not appreciably influenced by the host lipid matrix phase separation.

Cholesterol↗

PubMed1980

Circular dichroism study on structural reorganization of lectins by sodium dodecyl sulfate.

The circular dichroism (CD) spectra of lectins from Dolichos biflorus, Helix pomatia, Lotus tetragonolobus, Phaseolus vulgaris (erythroagglutinin), Pisum sativum, Sophora japonica, and Ulex europaeus I were analyzed, before and after the conformational transitions which were effected by sodium dodecyl sulfate (SDS) and change of pH. It was found that the pleated sheet conformation dominated in these lectins and that the best estimates of the amounts of the sheets can be made from the positive CD bands centered at 195 . 197 nm. The mean residue ellipticities of these bands in native lectins varied between 1.0 . 10(4) and 1.7 . 10(4) deg . cm2 . dmol-1. The conformation of the lectins was perturbed by SDS, which caused the CD bands related to the tyrosine and tryptophan chromophores to diminish and which also caused the reorganization of the main chains into new forms having approximately 15--40% of alpha-helix. Acid facilitated these transitions. The secondary structure of Ulex europaeus I lectin was resistant to SDS in neutral solutions but reorganization occurred in acid solutions. In Helix pomatia lectin the helices were formed chiefly from the aperiodic segments of the main chain. As structural perturbant, SDS was most effective at relatively high concentrations of 5 . 10(-3) to 5--10(-2) M, i.e. above the critical micelle concentration. Experiments with Pisum sativum and Sophora japonica lectins indicated that SDS below critical micelle concentration did not effect the tertiary structure of the lectins.

Circular Dichroism↗

PubMed1995

Developmentally-regulated lectin binding in the embryonic mouse telencephalon.

Cell-surface carbohydrate epitopes are important determinants in cell-cell and cell-matrix interactions, and oligosaccharide groups are structural components of many growth factor receptors and cell adhesion molecules. These epitopes may participate in the regulation of stem cell proliferation and differentiation during central nervous system development. To further understand these cellular phenomena, it is important to define the changes in neuroepithelial cell-surface carbohydrate expression during development. We used a panel of fluorescein-conjugated lectins to label live, freshly dissociated cells from the embryonic day 11 to 18 (E11 to E18) mouse telencephalon. The intensity and heterogeneity of lectin labeling was assessed by flow cytometry. The lectins that we examined exhibited widely varying levels of labeling intensity. Lectins with the highest degree of binding included cholera toxin B subunit (CTB), which binds primarily to the gangliosides GM1 and GD1b, phaseolus vulgaris erythroagglutinating lectin (PHA-E), which binds to a variety of cell adhesion molecules, and wheat germ agglutinin (WGA). Many lectins showed increasing labeling intensity and cellular heterogeneity as development progressed. To determine if the observed cellular heterogeneity in lectin binding reflected biological differences in neuroepithelial cell subpopulations, cells from the E14 telencephalon were separated into two populations based on their intensity of CTB labeling using a fluorescence activated cell sorter. The population of weakly CTB labeled cells contained more than four times as many cells in S-phase of the cell cycle than the population of intensely CTB labeled cells. These observations suggest that lectin cytochemistry and flow cytometry can be useful in identifying specific cell subpopulations of neuroepithelial precursor cells during development, allowing their isolation and characterization in vitro.

Animals↗