Search for associations between polymorphic variants of human acid chitinase gene and bronchial asthma in children of Novosibirsk

High prevalence of bronchial asthma among the population (about 300 million people all over the world) provides rationale for the search for candidate genes of disease. Human acidic chitinase (CHIA (AMCase)), encoded by the CHIA gene, is involved in the degradation of chitin, a component of the fungal cell wall and arthropod exoskeleton, which, if present in food or house dust, is a provoking factor for the bronchial asthma (BA) development. Functionally significant mutations in the CHIA gene may apparently increase the risk of susceptibility to BA.Aim. The aim of the study was to assess the associations of single nucleotide polymorphisms (SNPs) rs12033184 and rs3806448 in the CHIA gene with bronchial asthma in children in Novosibirsk.Material and Methods. The study was organized as case-control. A total of 537 blood samples were used. SNPs were determined by real-time PCR. The associations of polymorphic variants with the disease were assessed by the odds ratio.Results. No associations of rs12033184 and rs3806448 with BA were found.Conclusion. The role of acidic chitinase gene in the development of BA in residents of Novosibirsk was found to be less significant than in the Indian population where it was previously shown to be associated with the disease.

Characterization of the Chitinase Gene Family in Mulberry (Morus notabilis) and MnChi18 Involved in Resistance to Botrytis cinerea

Chitinase is a hydrolase that uses chitin as a substrate. It plays an important role in plant resistance to fungal pathogens by degrading chitin. Here, we conducted bioinformatics analysis and transcriptome data analysis of the mulberry (Morus notabilis) chitinase gene family to determine its role in the resistance to Botrytis cinerea. A total of 26 chitinase genes were identified, belonging to the GH18 and GH19 families. Among them, six chitinase genes were differentially expressed under the infection of B. cinerea. MnChi18, which significantly responded to B. cinerea, was heterologously expressed in Arabidopsis (Arabidopsis thaliana). The resistance of MnChi18 transgenic Arabidopsis to B. cinerea was significantly enhanced, and after inoculation with B. cinerea, the activity of catalase (CAT) increased and the content of malondialdehyde (MDA) decreased. This shows that overexpression of MnChi18 can protect cells from damage. In addition, our study also indicated that MnChi18 may be involved in B. cinerea resistance through other resistance-related genes. This study provides an important basis for further understanding the function of mulberry chitinase.

Molecular Characterization of E. Histolytica Strains Based on the Serine Rich Entamoeba Histolytica Protein (Srehp) And Chitinase Genes.

BACKGROUND: Even though E. histolytica is recognized as an effective pathogen, what determines the outcome of this infection is still not well understood. The present study was carried out to determine the genetic characteristics of E. histolytica isolates from two different regions in South Africa. METHOD: Diarrheal and non-diarrheal stool samples were collected from patients of all ages from Giyani and Pretoria. Different PCR protocols were used to identify E. histolytica and amplify the serine rich E. histolytica protein (SREHP) and chitinase genes. The profiles obtained were compared among the different samples.RESULTS: Out of 111 stool samples collected, 51 were positive by either PCR or microscopy and 14 samples were positive by both methods. The serine- rich E. histolytica protein was amplified in 26 samples. Out of the 26 samples (19) different SREHP profiles were obtained. SREHP #2 was obtained in 5 different samples, 4 from Pretoria and 1 from Giyani (2 diarrheal and 3 non-diarrheal). The chitinase gene was amplified from 51 samples and 22 different chitinase profiles were obtained. Of all the profiles, profile #4 was found in 6 different isolates, 5 from Giyani and 1 from Pretoria (3 symptomatic and 3 asymptomatic). However, profile # 18 was only found in formed stools from Giyani. CONCLUSIONS. The results obtained in this study have further confirmed the genetic heterogeneity of E. histolytica for the SREHP and chitinase genes which might have a significant influence in the outcome of amebic infection, depending on the genetic profile of the infecting strain.

A Cisgenic Approach in the Transformation of Bread Wheat cv. Saratovskaya 29 with Class I Chitinase Gene

Background: Bread wheat is one of the major crops grown worldwide, showing high demand for new varieties with traits such as pathogen resistance. As the public acceptance of transgenic plants remains low, a novel approach – cisgenesis – is being developed to introduce the genes from the same or closely related species. Objective: This study presents a cisgenic approach used for the transformation of wheat with class I chitinase gene derived from T. aestivum cv. Stepnaya 15, co-transformed with acetohydroxyacid synthase gene that provides tolerance to imidazolinone herbicides. Methods: Calli from immature embryos of spring bread wheat Triticum aestivum cv. Saratovskaya 29 were used for co-transformation with two independent Minimal Expression Units (MEUs): class I chitinase and Acetohydroxyacid Synthase (AHAS) gene. For identification of cisgenic plants, genomic DNA was extracted from the leaves of imazethapyr-resistant regenerant plants at the plantlets stage and screened by polymerase chain reaction. The efficiency of transformation was calculated as the relation of regenerated plants with chitinase gene insert to the total number of calli in the experiment. Results: The average transformation efficiency in four series of experiments (total number of calli - 2299) was found to be 1.84% (ranging from 0.3% to 3.4%), while total co-transformation efficiency reached 87.93%. Conclusion: The high efficiency of co-transformation in the experiment promotes it as a very useful technique for the production of wheat lines, free of the selectable marker gene. To our knowledge, this is the first report of cisgenic bread wheat, where both target and selectable genes are derived from wheat.

RNAi-Mediated Silencing of the Chitinase 5 Gene for Fall Webworm (Hyphantria cunea) Can Inhibit Larval Molting Depending on the Timing of dsRNA Injection

Chitinases, which are crucial enzymes required for chitin degradation and reconstruction, are often selectively considered to be effective molecular targets for pest control due to their critical roles in insect development. Although the Hyphantria cunea chitinase gene has been reported previously, its sequence characteristics, gene function, and feasibility as a potential target for pest management were absent. In the present study, we characterized the H. cunea chitinase gene and designated it HcCht5. Phylogenic and domain structure analysis suggested that HcCht5 contained the typical chitinase features and was clustered into chitinase group I. Tissue-specific and developmental expression pattern analysis with Real-Time Quantitative PCR (RT-qPCR) showed that HcCht5 was mainly expressed in the integument tissues and that the transcript levels peaked during molting. RNA interference (RNAi)-mediated silencing of HcCht5 caused 33.3% (2 ug) and 66.7% (4 ug) mortality rates after double-stranded RNA (dsRNA) injection. Importantly, the interference efficiency of HcCht5 depended on the injection time of double-stranded RNA (dsRNA), as the pre-molting treatment achieved molt arrest more effectively. In addition, transcriptome sequencing (RNA-seq) analysis of RNAi samples demonstrated silencing of the down-regulated HcCht5 genes related to chitin metabolism and molting hormone signaling, as well as genes related to detoxification metabolism. Our results indicate the essential role of HcCht5 in H. cunea development and detail the involvement of its gene function in the larval molting process.

Genome-wide identification and expression analysis of the Brassica oleracea L. chitin-binding genes and response to pathogens infections

Main conclusion Chitinase family genes were involved in the response of Brassica oleracea to Fusarium wilt, powdery mildew, black spot and downy mildew. Abstract Abstract Chitinase, a category of pathogenesis-related proteins, is believed to play an important role in defending against external stress in plants. However, a comprehensive analysis of the chitin-binding gene family has not been reported to date in cabbage (Brassica oleracea L.), especially regarding the roles that chitinases play in response to various diseases. In this study, a total of 20 chitinase genes were identified using a genome-wide search method. Phylogenetic analysis was employed to classify these genes into two groups. The genes were distributed unevenly across six chromosomes in cabbage, and all of them contained few introns (≤ 2). The results of collinear analysis showed that the cabbage genome contained 1–5 copies of each chitinase gene (excluding Bol035470) identified in Arabidopsis. The heatmap of the chitinase gene family showed that these genes were expressed in various tissues and organs. Two genes (Bol023322 and Bol041024) were relatively highly expressed in all of the investigated tissues under normal conditions, exhibiting the expression characteristics of housekeeping genes. In addition, under four different stresses, namely, Fusarium wilt, powdery mildew, black spot and downy mildew, we detected 9, 5, 8 and 8 genes with different expression levels in different treatments, respectively. Our results may help to elucidate the roles played by chitinases in the responses of host plants to various diseases.