Soil nematode abundance and functional group composition at a global scale.

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.

Nematode ascarosides attenuate mammalian type 2 inflammatory responses.

Mounting evidence suggests that nematode infection can protect against disorders of immune dysregulation. Administration of live parasites or their excretory/secretory (ES) products has shown therapeutic effects across a wide range of animal models for immune disorders, including asthma. Human clinical trials of live parasite ingestion for the treatment of immune disorders have produced promising results, yet concerns persist regarding the ingestion of pathogenic organisms and the immunogenicity of protein components. Despite extensive efforts to define the active components of ES products, no small molecules with immune regulatory activity have been identified from nematodes. Here we show that an evolutionarily conserved family of nematode pheromones called ascarosides strongly modulates the pulmonary immune response and reduces asthma severity in mice. Screening the inhibitory effects of ascarosides produced by animal-parasitic nematodes on the development of asthma in an ovalbumin (OVA) murine model, we found that administration of nanogram quantities of ascr#7 prevented the development of lung eosinophilia, goblet cell metaplasia, and airway hyperreactivity. Ascr#7 suppressed the production of IL-33 from lung epithelial cells and reduced the number of memory-type pathogenic Th2 cells and ILC2s in the lung, both key drivers of the pathology of asthma. Our findings suggest that the mammalian immune system recognizes ascarosides as an evolutionarily conserved molecular signature of parasitic nematodes. The identification of a nematode-produced small molecule underlying the well-documented immunomodulatory effects of ES products may enable the development of treatment strategies for allergic diseases.

A simplified quick microbial genomic DNA extraction via freeze-thawing cycles.

Effective isolation of high-quality genomic DNA is one of the essential steps in molecular biology, biochemistry, and genetic studies. Here we describe a simplified procedure based on repeated freeze-thawing cycles to isolate genomic DNA from different organisms of microbes (Burkholderia pyrrocinia JK-SH007, Bacillus pumilus HRl0, Botrytis cinerea) and nematodes (Bursaphelenchus xylophilus). The DNA extraction buffer includes 10% of CTAB; 4% of NaCl (W/V); 20 mM of ethylenediamine tetraacetic acid; 100 mM of Tris-HCl, pH 8.0 and 1% of polyvinylpyrrolidone. The released DNA was purified from the mixture using a phenol/chloroform mixture and precipitated in 70% ethanol to remove proteins, carbohydrates, phenols, RNA, etc. Our method is a reproducible, simple, and rapid technique for routine DNA extractions from various microorganisms and nematodes. Furthermore, the low cost of this method could be an economic benefit to large-scale studies.

The role of fish helminth parasites in monitoring metal pollution in aquatic ecosystems: a case study in the world's most productive platinum mining region.

Due to the increasing consumption of platinum (Pt), especially in automobile exhaust catalysts, environmental concentrations of Pt are of emerging concern worldwide. Limited information exists on environmental concentrations, particularly in Pt mining regions, while South Africa is the world's main supplier of Pt. Moreover, other metals are also released as by-products of Pt mining, which might also cause environmental concern. Certain fish parasite taxa have the ability to accumulate metals orders of magnitude higher than their hosts and can be used to reliably detect metals with naturally low abundance. Studies on Pt accumulation in parasite-host systems are limited. Therefore, the aims of the present study were (1) to determine the accumulation of a variety of metals (cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), platinum (Pt), and zinc (Zn)) in helminth fish parasites compared with their hosts from a reference site and an impoundment impacted by Pt mining activities; (2) to assess whether there is a difference between bioaccumulation of metals in infected and uninfected hosts, as well as between hosts with different infection intensities; and (3) to compare the biomarker responses (acetylcholine esterase activity (AChE), metallothionein content (MT), catalase activity (CAT), reduced glutathione content (GSH), malondialdehyde content (MDA), protein carbonyls induction (PC), superoxide dismutase activity (SOD), and cellular energy allocation (CEA)) between infected and uninfected hosts. The cestode Atractolytocestus huronensis accumulated significantly higher concentrations of Cr, Ni, and Pt than their host Cyprinus carpio, while the nematode Contracaecum sp. accumulated significantly higher concentrations of Pt and Zn than their host Clarias gariepinus. Infected fish showed lower metal concentrations compared to uninfected fish, while the parasites had no significant effects on their hosts' biomarker responses. The parasites demonstrated the bioavailability of metals derived from Pt mining activities and their ability to resist its toxic effects. Thus, these parasites are promising sensitive accumulation indicators for Cr, Ni, Pb, and Pt contaminations from Pt mining activities.

Photoaffinity probes for nematode pheromone receptor identification.

Identification of pheromone receptors plays a central role for uncovering signaling pathways that underlie chemical communication in animals. Here, we describe the synthesis and bioactivity of photoaffinity probes for the ascaroside ascr#8, a sex-pheromone of the model nematode, Caenorhabditis elegans. Structure-activity studies guided incorporation of alkyne- and diazirine-moieties and revealed that addition of functionality in the sidechain of ascr#8 was well tolerated, whereas modifications to the ascarylose moiety resulted in loss of biological activity. Our study will guide future probe design and provides a basis for pheromone receptor identification via photoaffinity labeling in C. elegans.

Characterization of bactericidal efficiency, cell selectivity, and mechanism of short interspecific hybrid peptides.

Facing rising global antibiotics resistance, physical membrane-damaging antimicrobial peptides (AMPs) represent promising antimicrobial agents. Various strategies to design effective hybrid peptides offer many advantages in overcoming the adverse effects of natural AMPs. In this study, hybrid peptides from different species were investigated, and three hybrid antimicrobial peptides, LI, LN, and LC, were designed by combining the typical fragment of human cathelicidin-derived LL37 with either indolicidin, pig nematode cecropin P1 (CP-1) or rat neutrophil peptide-1 (NP-1). In an aqueous solution, all hybrid peptides had an unordered conformation. In simulated membrane conditions, the hybrid peptide LI displayed more ß-turn and ß-hairpin structures, whereas LN and LC folded into α-helix structures. The three interspecific hybrid peptides LI, LN, and LC exhibited different levels of antimicrobial activity against Gram-positive and Gram-negative bacteria. LI demonstrated the highest antimicrobial activity and cell selectivity. The results of the swimming motility indicated that LI repressed bacterial motility in a concentration-dependent method. Endotoxin binding assay demonstrated that hybrid peptide LI conserved the binding ability to LPS (polyanionic lipopolysaccharides) of its parental peptides. Fluorescence assays, flow cytometry, and SEM further revealed that hybrid peptide LI acted through different bacteriostatic mechanisms than LL37 and indolicidin and that LI killed bacterial cells via membrane damage. In summary, this study demonstrated that hybrid peptide LI produced by interspecific hybrid synthesis possessed strong cell selectivity and is a promising therapeutic candidate for drug-resistant bacteria infection.

Cysteine-Derived Pleurotin Congeners from the Nematode-Trapping Basidiomycete Hohenbuehelia grisea.

The discovery of a Hohenbuehelia grisea specimen during a field trip in Northern Thailand led to the isolation and identification of three novel sulfur-bearing derivatives of dihydropleurotinic acid (4). Thiopleurotinic acid A (1) was established by the interpretation of spectral data (HRESIMS, 2D-NMR) as a 2-hydroxy-3-mercaptopropanoic acid conjugate of dihydropleurotinic acid. Thiopleurotinic acid B (2) was shown to be the N-acetylcysteine conjugate of 4. A third compound (3) was established as a thiazole-containing derivative. Through feeding experiments with [U-13C3, 15N]-l-cysteine the formation of all three metabolites was shown to involve cysteine condensation with 4. The decreased cytotoxicity and antimicrobial activities of the new derivatives 1-3, compared to the parent compound 4, indicate a possible detoxification pathway of filamentous fungi.

The Distribution of Lectins across the Phylum Nematoda: A Genome-Wide Search.

Nematodes are a very diverse phylum that has adapted to nearly every ecosystem. They have developed specialized lifestyles, dividing the phylum into free-living, animal, and plant parasitic species. Their sheer abundance in numbers and presence in nearly every ecosystem make them the most prevalent animals on earth. In this research nematode-specific profiles were designed to retrieve predicted lectin-like domains from the sequence data of nematode genomes and transcriptomes. Lectins are carbohydrate-binding proteins that play numerous roles inside and outside the cell depending on their sugar specificity and associated protein domains. The sugar-binding properties of the retrieved lectin-like proteins were predicted in silico. Although most research has focused on C-type lectin-like, galectin-like, and calreticulin-like proteins in nematodes, we show that the lectin-like repertoire in nematodes is far more diverse. We focused on C-type lectins, which are abundantly present in all investigated nematode species, but seem to be far more abundant in free-living species. Although C-type lectin-like proteins are omnipresent in nematodes, we have shown that only a small part possesses the residues that are thought to be essential for carbohydrate binding. Curiously, hevein, a typical plant lectin domain not reported in animals before, was found in some nematode species.

[Blue death of nematodes.]

This paper shows that the aging and death of nematodes, accompanied by the ignition of a blue glow under fluorescent microscopy, are not directly linked to any lipofuscin (aging pigment), nor with the anthranilic acid (a product of degradation of tryptophan residues of proteins). The main contribution in the blue flash of the dying nematodes belongs to parasitic light, scattered on the cuticle and bodies of the worm. The main contribution in the blue region at spectrofluorometry of homogenates, obtained from nematodes, really gives anthranilic acid. However, the content of anthranilic acid, measured by spectrofluorimetry, in adult nematodes is lower than that in the young ones. Artificial aging of nematodes by moderate heating revealed no accumulation of anthranilate and no loss of tryptophan, from which it must be formed. Thus, it is hardly lipofuscin or anthranilic acid. The cause of aging and death of nematodes is the formation of strong cross-links between proteins. This is supported by data on tryptophan fluorescence and light scattering of homogenates: the old worms show a large number of denaturated proteins and large protein particles with a strong cross-links, which are not destroyed be detergent.

Simultaneous Quantitation of Free Amino Acids, Nucleosides and Nucleobases in Sipunculus nudus by Ultra-High Performance Liquid Chromatography with Triple Quadrupole Mass Spectrometry.

To evaluate the nutritional and functional value of Sipunculus nudus, a rapid, simple and sensitive analytical method was developed using ultra-high performance liquid chromatography coupled with a triple quadrupole mass detection in multiple-reaction monitoring mode for the simultaneous quantitative determination of 25 free amino acids and 16 nucleosides and nucleobases in S. nudus within 20 min, which was confirmed to be reproducible and accurate. The limits of detection (LODs) and quantification (LOQs) were between 0.003-0.229 µg/mL and 0.008-0.763 µg/mL for the 41 analytes, respectively. The established method was applied to analyze 19 batches of S. nudus samples from four habitats with two different processing methods. The results showed that S. nudus contained a variety of free amino acids, nucleosides and nucleobases in sufficient quantity and reasonable proportion. They also demonstrated that the contents of these compounds in different parts of S. nudus were significantly discriminating, which were in the order: (highest) coelomic fluid > body wall > intestine (lowest). The method is simple and accurate, and could serve as a technical support for establishing quality control of S. nudus and other functional seafoods. Moreover, the research results also laid foundation for further exploitation and development of S. nudus.

Combinatorial chemistry in nematodes: modular assembly of primary metabolism-derived building blocks.

The nematode Caenorhabditis elegans was the first animal to have its genome fully sequenced and has become an important model organism for biomedical research. However, like many other animal model systems, its metabolome remained largely uncharacterized, until recent investigations demonstrated the importance of small molecule-based signalling cascades for virtually every aspect of nematode biology. These studies have revealed that nematodes are amazingly skilled chemists: using simple building blocks from conserved primary metabolism and a strategy of modular assembly, C. elegans and other nematode species create complex molecular architectures to regulate their development and behaviour. These nematode-derived modular metabolites (NDMMs) are based on the dideoxysugars ascarylose or paratose, which serve as scaffolds for attachment of moieties from lipid, amino acid, carbohydrate, citrate, and nucleoside metabolism. Mutant screens and comparative metabolomics based on NMR spectroscopy and MS have so-far revealed several 100 different ascarylose ("ascarosides") and a few paratose ("paratosides") derivatives, many of which represent potent signalling molecules that can be active at femtomolar levels, regulating development, behaviour, body shape, and many other life history traits. NDMM biosynthesis appears to be carefully regulated as assembly of different modules proceeds with very high specificity. Preliminary biosynthetic studies have confirmed the primary metabolism origin of some NDMM building blocks, whereas the mechanisms that underlie their highly specific assembly are not understood. Considering their functions and biosynthetic origin, NDMMs represent a new class of natural products that cannot easily be classified as "primary" or "secondary". We believe that the identification of new variants of primary metabolism-derived structures that serve important signalling functions in C. elegans and other nematodes provides a strong incentive for a comprehensive re-analysis of metabolism in higher animals, including humans.

Comparison of RP-HPLC modes to analyse the N-glycome of the free-living nematode Pristionchus pacificus.

Pristionchus pacificus is a free-living nematode increasingly used as an organism for comparison to the more familiar model Caenorhabditis elegans. In this study, we examined the N-glycans of this organism isolated after serial release with peptide:N-glycosidases F and A; after fluorescent labelling with 2-aminopyridine, chromatographic fractionation by three types of RP-HPLC (with either classical C18, fused core C18 or alkylamide-bonded phases) followed by mass spectrometric analyses revealed key features of its N-glycome. In addition to paucimannosidic and oligomannosidic glycans typical of invertebrates, N-glycans with two core fucose residues were detected. Furthermore, a range of glycans carrying up to three phosphorylcholine residues was observed whereas, unlike C. elegans, no tetrafucosylated N-glycans were detected. Structures with three fucose residues, unusual methylation of core α1,3-fucose or with galactosylated fucose motifs were found in low amounts; these features may correlate with a different ensemble or expression of glycosyltransferase genes as compared to C. elegans. From an analytical perspective, both the alkylamide RP-amide and fused core C18 columns, as compared to a classical C18 material, offer advantages in terms of resolution and of elution properties, as some minor pyridylamino-labelled glycans (e.g. those carrying phosphorylcholine) appear in earlier fractions and so potential losses of such structures due to insufficient gradient length can be avoided.

Glutamate-gated chloride channels.

Glutamate-gated chloride channels (GluCls) are found only in protostome invertebrate phyla but are closely related to mammalian glycine receptors. They have a number of roles in these animals, controlling locomotion and feeding and mediating sensory inputs into behavior. In nematodes and arthropods, they are targeted by the macrocyclic lactone family of anthelmintics and pesticides, making the GluCls of considerable medical and economic importance. Recently, the three-dimensional structure of a GluCl was solved, the first for any eukaryotic ligand-gated anion channel, revealing a macrocyclic lactone-binding site between the channel domains of adjacent subunits. This minireview will highlight some unique features of the GluCls and illustrate their contribution to our knowledge of the entire Cys loop ligand-gated ion channel superfamily.

Effects of Group 3 LEA protein model peptides on desiccation-induced protein aggregation.

Group 3 late embryogenesis abundant (G3LEA) proteins have amino acid sequences with characteristic 11-mer motifs and are known to reduce aggregation of proteins during dehydration. Previously, we clarified the structural and thermodynamic properties of the 11-mer repeating units in G3LEA proteins using synthetic peptides composed of two or four tandem repeats originating from an insect (Polypedilum vanderplanki), nematodes and plants. The purpose of the present study is to test the utility of such 22-mer peptides as protective reagents for aggregation-prone proteins. For lysozyme, desiccation-induced aggregation was abrogated by low molar ratios of a 22-mer peptide, PvLEA-22, derived from a P. vanderplanki G3LEA protein sequence. However, an unexpected behavior was noted for the milk protein, α-casein. On drying, the resultant aggregation was significantly suppressed in the presence of PvLEA-22 with its molar ratios>25 relative to α-casein. However, when the molar ratio was <10, aggregation occurred on addition of PvLEA-22 to aqueous solutions of α-casein. Other peptides derived from nematode, plant and randomized G3LEA protein sequences gave similar results. Such an anomalous solubility change in α-casein was shown to be due to a pH shift to ca. 4, a value nearly equal to the isoelectric point (pI) of α-casein, when any of the 22-mer peptides was mixed. These results demonstrate that synthetic peptides derived from G3LEA protein sequences can reduce protein aggregation caused both by desiccation and, at high molar ratios, also by pH effects, and therefore have potential as stabilization reagents.

Purification and characterization of a glycoprotein from Sipunculus nudus and its immune-enhancing activity to RAW 264.7 macrophages.

Sipunculus nudus, an edible marine invertebrate, has long been used as traditional Chinese medicine in folk remedies. In order to assess the immunoregulatory activity of glycoproteins in Sipunculus nudus and conduct a structure-activity relationship, a glycoprotein (SGP1) with molecular mass of 9.26 kDa was purified from Sipunculus nudus, and its chemical structure as well as immune-enhancing activity was investigated in this study. Structure analysis revealed that SGP1, a protein-dominate glycoprotein with O-glycosidic bonds, contained 92.8 % protein and 3.1 % saccharide. GC-MS result indicated that the saccharide moieties of SGP1 basically consisted of lyxose (Lyx), xylose (Xyl) as well as glucose (Glu) at a molar proportion of 0.87:4.16:1.36. The fourier transform infrared specoscopy (FT-IR) result proved that SGP1 have a typical characteristic of glycoprotein. Besides, circular dichroism (CD) result showed that SGP1 contained 4.1 % α-helix, 42.5 % ß-sheet, 21.4 % ß-turn, and 32.0 % random coil, indicating it's mainly a ß-sheet glycoprotein. The amino acid sequence of SGP1 shared a similarity to the Myohemerythrin (sp|Q5K473|HEMTM) with protein sequence coverage of 28.3 %. Moreover, the activity evaluation results showed that SGP1 exhibited significant immune-enhancing activity to the RAW 264.7 macrophages by promoting macrophages proliferation, enhancing phagocytic capacity, and simultaneously stimulating the secretions of nitric oxide (NO), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) via NF-κB pathways. In this study, SGP1 as a novel glycoprotein had an obvious immune-enhancing activity to macrophages, and thus could be applied in the functional foods as a potential immunopotentiator for the hypoimmune population.

Potential of MALDI-TOF mass spectrometry as a rapid detection technique in plant pathology: identification of plant-associated microorganisms.

Plant diseases caused by plant pathogens substantially reduce crop production every year, resulting in massive economic losses throughout the world. Accurate detection and identification of plant pathogens is fundamental to plant pathogen diagnostics and, thus, plant disease management. Diagnostics and disease-management strategies require techniques to enable simultaneous detection and quantification of a wide range of pathogenic and non-pathogenic microorganisms. Over the past decade, rapid development of matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques for characterization of microorganisms has enabled substantially improved detection and identification of microorganisms. In the biological sciences, MALDI-TOF MS is used to analyze specific peptides or proteins directly desorbed from intact bacteria, fungal spores, nematodes, and other microorganisms. The ability to record biomarker ions, in a broad m/z range, which are unique to and representative of individual microorganisms, forms the basis of taxonomic identification of microorganisms by MALDI-TOF MS. Recent advances in mass spectrometry have initiated new research, i.e. analysis of more complex microbial communities. Such studies are just beginning but have great potential for elucidation not only of the interactions between microorganisms and their host plants but also those among different microbial taxa living in association with plants. There has been a recent effort by the mass spectrometry community to make data from large scale mass spectrometry experiments publicly available in the form of a centralized repository. Such a resource could enable the use of MALDI-TOF MS as a universal technique for detection of plant pathogens and non-pathogens. The effects of experimental conditions are sufficiently understood, reproducible spectra can be obtained from computational database search, and microorganisms can be rapidly characterized by genus, species, or strain.

Hierarchical alignment and full resolution pattern recognition of 2D NMR spectra: application to nematode chemical ecology.

Nuclear magnetic resonance (NMR) is the most widely used nondestructive technique in analytical chemistry. In recent years, it has been applied to metabolic profiling due to its high reproducibility, capacity for relative and absolute quantification, atomic resolution, and ability to detect a broad range of compounds in an untargeted manner. While one-dimensional (1D) (1)H NMR experiments are popular in metabolic profiling due to their simplicity and fast acquisition times, two-dimensional (2D) NMR spectra offer increased spectral resolution as well as atomic correlations, which aid in the assignment of known small molecules and the structural elucidation of novel compounds. Given the small number of statistical analysis methods for 2D NMR spectra, we developed a new approach for the analysis, information recovery, and display of 2D NMR spectral data. We present a native 2D peak alignment algorithm we term HATS, for hierarchical alignment of two-dimensional spectra, enabling pattern recognition (PR) using full-resolution spectra. Principle component analysis (PCA) and partial least squares (PLS) regression of full resolution total correlation spectroscopy (TOCSY) spectra greatly aid the assignment and interpretation of statistical pattern recognition results by producing back-scaled loading plots that look like traditional TOCSY spectra but incorporate qualitative and quantitative biological information of the resonances. The HATS-PR methodology is demonstrated here using multiple 2D TOCSY spectra of the exudates from two nematode species: Pristionchus pacificus and Panagrellus redivivus. We show the utility of this integrated approach with the rapid, semiautomated assignment of small molecules differentiating the two species and the identification of spectral regions suggesting the presence of species-specific compounds. These results demonstrate that the combination of 2D NMR spectra with full-resolution statistical analysis provides a platform for chemical and biological studies in cellular biochemistry, metabolomics, and chemical ecology.

The parasitic nematodes Hysterothylacium sp. type MB larvae as bioindicators of lead and cadmium: a comparative study of parasite and host tissues.

Cadmium and lead concentrations were compared in tissues of cutlassfish, Trichiurus lepturus L., its intestinal nematode Hysterothylacium sp. type MB larvae, and in water from the same location in the Sea of Oman. Metal accumulation in hosts, parasites and sea water was measured by ICP-OES. Hysterothylacium larvae from the intestinal lumen and visceral cavity showed much higher metal concentrations than in host tissues or sea water. Statistical analyses revealed no significant differences in metal accumulation between infected and uninfected hosts. Cadmium concentration in the host muscle was lower than in intestine, liver and gonad tissues. The mean concentrations of lead and cadmium in nematodes were 289·03 and 81·5 times higher than in host intestine, 188·4 and 225 times higher than in host muscle, 108·6 and 65·3 times higher than in host gonads, 70·5 and 19·5 times higher than in host liver and 3351 and 148 times higher than in sea water. The results show the value of this and possibly related nematodes as bioindicators of heavy metals and their potential use in environmental studies.

The polyprotein allergens of nematodes (NPAs) - structure at last, but still mysterious.

We are engaged in structural and functional studies of several types of lipid binding protein that are only found in nematodes. Amongst these are the nematode polyprotein allergens (NPAs) and we now report the solution structure of ABA-1A (As-NPA-A1), the most repeated unit within the NPA array of Ascaris suum, which is almost identical in amino acid sequence to that of Ascaris lumbricoides. The protein forms a slightly flattened, compact, globular fold consisting of a long central helix that participates in two flanking helical bundles. Two pockets lined with apolar amino acid sidechains are apparent, one in the carboxy-terminal region of the protein, and another smaller one in the amino-terminal region. The former appears to be the main site of fatty acid binding, and the latter may have different, though possibly overlapping, ligand binding propensities. The structure of the binding sites indicates that lipid ligands are anchored within them with their hydrophobic tails oriented towards the core of the protein and their polar headgroups bound to charged sidechains at the mouth of the pockets. The three-dimensional architectures of the amino- and carboxy-terminal halves of ABA-1A are closely similar, thereby strengthening the long-suspected idea that the repeated units of NPAs themselves originate from an ancient duplication event.

CCS52 and DEL1 function in root-knot nematode giant cell development in Xinjiang wild myrobalan plum (Prunus sogdiana Vassilcz).

Root-knot nematodes (RKNs) are highly invasive plant parasites that establish permanent feeding sites within the roots of the host plant. Successful establishment of the feeding site is essential for the survival of RKN. The formation and development of the feeding cell, also called giant cell, involve both cell division and endoreduplication. Here, we examined giant cell development and endoreduplication in Prunus sogdiana infected with the RKN. We found that feeding sites were established 3-5 days post inoculation (dpi) and matured at 21-28 dpi. The giant cells began to form 5 dpi and continued to increase in size from 7 to 21 dpi. The large numbers of dividing nuclei were observed in giant cells from 7 to 14 dpi. However, nuclear division was rarely observed after 28 days. RT-PCR and in situ hybridization analyses revealed that PsoCCS52A was abundantly expressed at 7-21 dpi and the PsoCCS52A signal observed in giant cell nucleus at 7-14 dpi. The PsoCCS52B is highly expressed at 14 dpi, and the hybridization signal was mainly in the cytoplasm of giant cells. The PsoDEL1 expression was lowest 7-21 dip, with negligible transcript detected in the giant cells. This indicates that the PsoCCS52A plays a role in the process of cell division, while the CCS52B plays a role in the development of giant cells. The PsoDEL1 plays a negative regulatory role in megakaryocyte nuclear replication. These data suggest that an increased expression of PsoCCS52A promotes nuclear division and produces a large number of polyploid nuclei, the area of giant cells and feeding sites increase, ultimately leading to the formation of galls in Prunus sogdiana.