Action of circulating and infiltrating B cells in the immune microenvironment of colorectal cancer by single-cell sequencing analysis

BACKGROUND The complexity of the immune microenvironment has an impact on the treatment of colorectal cancer(CRC),one of the most prevalent malignancies worldwide.In this study,multi-omics and single-cell sequencing techniques were used to investigate the mechanism of action of circulating and infiltrating B cells in CRC.By revealing the heterogeneity and functional differences of B cells in cancer immunity,we aim to deepen our understanding of immune regulation and provide a scientific basis for the development of more effective cancer treatment strategies.AIM To explore the role of circulating and infiltrating B cell subsets in the immune microenvironment of CRC,explore the potential driving mechanism of B cell development,analyze the interaction between B cells and other immune cells in the immune microenvironment and the functions of communication molecules,and search for possible regulatory pathways to promote the anti-tumor effects of B cells.METHODS A total of 69 paracancer(normal),tumor and peripheral blood samples were collected from 23 patients with CRC from The Cancer Genome Atlas database(https://portal.gdc.cancer.gov/).After the immune cells were sorted by multicolor flow cytometry,the single cell transcriptome and B cell receptor group library were sequenced using the 10X Genomics platform,and the data were analyzed using bioinformatics tools such as Seurat.The differences in the number and function of B cell infiltration between tumor and normal tissue,the interaction between B cell subsets and T cells and myeloid cell subsets,and the transcription factor regulatory network of B cell subsets were explored and analyzed.RESULTS Compared with normal tissue,the infiltrating number of CD20+B cell subsets in tumor tissue increased significantly.Among them,germinal center B cells(GCB)played the most prominent role,with positive clone expansion and heavy chain mutation level increasing,and the trend of differentiation into memory B cells increased.However,the number of plasma cells in the tumor microenvironment decreased significantly,and the plasma cells secreting IgA antibodies decreased most obviously.In addition,compared with the immune microenvironment of normal tissues,GCB cells in tumor tissues became more closely connected with other immune cells such as T cells,and communication molecules that positively regulate immune function were significantly enriched.CONCLUSION The role of GCB in CRC tumor microenvironment is greatly enhanced,and its affinity to tumor antigen is enhanced by its significantly increased heavy chain mutation level.Meanwhile,GCB has enhanced its association with immune cells in the microenvironment,which plays a positive anti-tumor effect.

Safety assessment of a novel marine multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 according to phenotype and whole genome-sequencing analysis

The application of microorganisms as probiotics is limited due to lack of safety evaluation.Here,a novel multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 with aroma-producing properties was identified from marine mangrove microorganisms.Its safety and probiotic properties were assessed in accordance with phenotype and whole-genome sequencing analysis.Results showed that the genes and phenotypic expression of related virulence,antibiotic resistance and retroelement were rarely found.Hyphal morphogenesis genes(SIT4,HOG1,SPA2,ERK1,ICL1,CST20,HSP104,TPS1,and RHO1)and phospholipase secretion gene(VPS4)were annotated.True hyphae and phospholipase were absent.Only one retroelement(Tad1-65_BG)was found.Major biogenic amines(BAs)encoding genes were absent,except for spermidine synthase(JA9_002594),spermine synthase(JA9_004690),and tyrosine decarboxylase(inx).The production of single BAs and total BAs was far below the food-defined thresholds.GXDK6 had no resistance to common antifungal drugs.Virulence enzymes,such as gelatinase,DNase,hemolytic,lecithinase,and thrombin were absent.Acute toxicity test with mice demonstrated that GXDK6 is safe.GXDK6 has a good reproduction ability in the simulation gastrointestinal tract.GXDK6 also has a strong antioxidant ability,β-glucosidase,and inulinase activity.To sum up,GXDK6 is considered as a safe probiotic for human consumption and food fermentation.

Cloning and Sequence Analysis of Actin Gene from Rehmannia glutinosa

[ Objective ] The aim of this study is to clone and analyze the actin gene from Rehmannia glutinosa. [ Method ] Degenerate primers were designed according to the conserved regions of actin sequences of Rehmannia glutinosa and its similar species, RT-PCR was next conducted to amplify the actin gene from Rehmannia glutinosa. [ Result] The amplified fragment is 724 bp and correspondingly 240 amino acids. The BLAST results indicate that the homology between the amplified fragment and other higher plants for aetin gene sequences and amino acid are more than 80% and 90%, respectively, suggesting that the amplified fragment is the actin gene of Rehmannia glutinosa. [ Conclusion] Phylogenetic analysis shows that the actin gene of Rehmannia glutinosa has an intimate genetic relationship with actin7 gene of Nicotiana tabacum.

Screening biomarkers for spinal cord injury using weighted gene co-expression network analysis and machine learning

Immune changes and inflammatory responses have been identified as central events in the pathological process of spinal co rd injury.They can greatly affect nerve regeneration and functional recovery.However,there is still limited understanding of the peripheral immune inflammato ry response in spinal cord inju ry.In this study.we obtained microRNA expression profiles from the peripheral blood of patients with spinal co rd injury using high-throughput sequencing.We also obtained the mRNA expression profile of spinal cord injury patients from the Gene Expression Omnibus(GEO)database(GSE151371).We identified 54 differentially expressed microRNAs and 1656 diffe rentially expressed genes using bioinformatics approaches.Functional enrichment analysis revealed that various common immune and inflammation-related signaling pathways,such as neutrophil extracellular trap formation pathway,T cell receptor signaling pathway,and nuclear factor-κB signal pathway,we re abnormally activated or inhibited in spinal cord inju ry patient samples.We applied an integrated strategy that combines weighted gene co-expression network analysis,LASSO logistic regression,and SVM-RFE algorithm and identified three biomarke rs associated with spinal cord injury:ANO10,BST1,and ZFP36L2.We verified the expression levels and diagnostic perfo rmance of these three genes in the original training dataset and clinical samples through the receiver operating characteristic curve.Quantitative polymerase chain reaction results showed that ANO20 and BST1 mRNA levels were increased and ZFP36L2 mRNA was decreased in the peripheral blood of spinal cord injury patients.We also constructed a small RNA-mRNA interaction network using Cytoscape.Additionally,we evaluated the proportion of 22 types of immune cells in the peripheral blood of spinal co rd injury patients using the CIBERSORT tool.The proportions of naive B cells,plasma cells,monocytes,and neutrophils were increased while the proportions of memory B cells,CD8^(+)T cells,resting natural killer cells,resting dendritic cells,and eosinophils were markedly decreased in spinal cord injury patients increased compared with healthy subjects,and ANO10,BST1 and ZFP26L2we re closely related to the proportion of certain immune cell types.The findings from this study provide new directions for the development of treatment strategies related to immune inflammation in spinal co rd inju ry and suggest that ANO10,BST2,and ZFP36L2 are potential biomarkers for spinal cord injury.The study was registe red in the Chinese Clinical Trial Registry(registration No.ChiCTR2200066985,December 12,2022).

Sequence Analysis of Polymorphic Fragments in the Third Intron of Porcine H-FABP Gene

[ Objective] The aim of this study was to provide a theoretical basis for exploring the major genes affecting intramuscular fat （IMF） deposition. [Method] Taking 383 pigs from five breeds including Mashen Pig, Large White Pig, Landrace, Duroc and Shanxi White Pig as the experimental animals, polymorphisms of partial fragments in the third intron of porcine H-FABP gene were detected by PCR-SSCP method, and then the polymorphic fragments were sequenced. [ Result] Two alleles, designated as A and B, were found at the locus 346 in the third intron of porcine H-FABP gene, and the mutation was caused by a A→G substitution. [ Conclusion] A polymorphic locus was discovered in the third intron of porcine H-FABP gene in this experiment, laying a foundation for the further study on the relationship between H-FABP gene and IMF content.

Molecular Cloning and Sequence Analysis of Class Ⅱ Chitinase Gene in Leymus chinensis

[ Objective] The aim of this study was to clone Class Ⅱ chitinase gene in Leymus chinensis grown in saline land in Heilongjiang Province and analyze its sequence, which provided a foundation for further study on the biological function and application of chitinasa gene. [ Method] cDNA library of Leymus chinensis leaves were constructed, and its DNA sequence was determined or analyzed, while the homology of chitinasa gene and amino acid sequence was compared with that in GenBank. [ Result] One full length cDNA fragment with length of 996 bp was cloned from cDNA library of Leymus chinensis leaves. The length of ORF was 768 bp encoding 225 amino acids （GenBank accession number： EU344908）. The encoding products lacked CBD and C-terminal extension region from the view of structure, but had structural characters of Class Ⅱ chitinase gene, which indicated that amino acid sequence had high homology compared with Class Ⅱ chitinase gene of rye and wheat. The constructed recombinant vector pQE-LcChi2 could express a protein of 27 kD through induction, which was consistent with the deduced encoding product of pQE-LcChi2 gene. [ Conclusion] LcChl2 gene is an expression gene, which can express in E. coll.

Sequence Analysis of HA Genes from Three H9N2 Subtype Avian Influenza Viruses

[ Objective] The study aimed to understand the genetic characters of H9N2 subtype avian influenza viruses isolated in Belling area. [ Method] HA genes of three H9N2 subtype avian influenza viruses A/Chicken/Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/ liu/00 were amplified by RT-PCR and then sequenced. [ Result] The results of phylogenetic analysis showed that A/Chicken/Beijing/xu/00, A/ Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 shared the nucleotide homologies of 84.8% （ Dk/HK/Y439/97 ） -98.0% （ Ck/GX17/00 ）, 85.1% （Dk/HK/Y439/97） - 99.1% （ Ck/GXl 7/00）, 90.7% （ Ck/BJ/3/01 ） - 99.1% （Ck/GX17/00） with the isolates from Hongkong and other are- as of Chinese Mainland respectively. At the same time, the analysis of amino acid indicated that the three isolates belonged to low pathogenic H9N2 isolates of avian origin. The 226^th amino acid of them were L （ Leu）, suggesting their high binding affinity to human cells. There were seven glyco- sylation sites in HA protein, five from HA1 and two from HA2. [ Cenclusien] By analysis at molecular level, it could be concluded that A/Chicken/ Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 were low pathogenic H9N2 isolates of avian origin.

Determination and Analysis of Mitochondrial ND2 Gene Sequence of Anas platyrhynchos

[Objective] The study was to analyze the phylogenesis of Anas platyrhynchos. [Method] Complete sequence of mitochondrial ND2 gene of 4 Anas platyrhynchos was determined by direct DNA sequencing based on PCR products. Combined with ND2 gene sequences of the Anas Linnaeus accessed in GenBank, phylogenetic tree was constructed by Neighbor-joining and maximum parsimony methods. [Result] The ND2 gene sequences of 4 Anas platyrhynchos were identical(1 041 bp in length; the nucleotide contents of A, G, T, and C were 28.91%, 13.35%, 20.75% and 36.98% respectively; A+T content approximated to that of C+G). Sequences of ND2 gene of mallard were same as spotbill duck, and had high homology with others. The phylogenetic trees indicated mallard and spotbilled duck were close in genetic relationship, both shared a haplotype; then Philippine duck, green-winged teal and northern pintail fell into branch ''A". [Conclusion] The domestic duck may be domesticated from mallard and spotbilled duck.

Isolation of Rice EPSP Synthase cDNA and Its Sequence Analysis and Copy Number Determination

In order to isolate the total cDNA of rice (Oryza sativa L.) epsps gene, RT-PCR was carried out with template of rice first-strand cDNA and primers designed according to rice EPSP synthase genomic sequence obtained in previous study. A 1 585-bp cDNA fragment was amplified and cloned. The 1 585-bp cDNA contains an open reading frame (ORF) comprising of 1 533 nucleotides (nt) which encodes a 511 residue polypepetides, including 67 amino acids chloroplast transit peptide and 444 amino acids EPSP synthase mature peptide. A comparison between the EPSP synthase of different sources indicates that the mature peptide shows more than 51% identity except for the fungi EPSP synthase and the transit peptide shows considerably less sequence conservation. The copy number of rice epsps gene is estimated to be one copy per haploid rice genome using southern blot. RT-PCR indicated that rice epsps gene is expressed in rice leaves, endosperms and roots and has the highest expression level in leaves.

Cloning and Sequence Analysis of 16S rRNA and COI Gene in Mitochondrial DNA of Scortum barcoo

[Objective] The aim was to provide molecular biological basis for the researches on the genetic resources,genetic relationship among species and phyletic evolution of S.barcoo.[Method] PCR amplification and sequencing were used to study the 16S rRNA and COI gene fragments.[Result] As for 16S rRNA gene fragments,nucleotide sequences of 791 bp were obtained,and the A,T,G and C contents in this fragment were 31.6%,21.4%,20.4% and 26.7%respectively.As for the COI gene fragments,the size was 631 bp and the A,T,G And C contents were 27.7%,23.6%,29.8% and 18.9% respectively.Among these two gene fragments,the content of GC was lower than AT,and AT/GC of these two fragments was 1.13 and 1.05 respectively.[Conclusion] The genetic characteristics of gene fragments of 16S rRNA and COI of S.barcoo suggested that the variation in the same species was relatively low.The sequences of 16S rRNA gene in three samples the same,while the sequences of COI gene was also the same,indicating that these two gene of S.barcoo were conservative.

Cloning and Sequence Analysis of Lactate Dehydrogenase C(LDH-C)Gene from Black-lipped Pika in Western Sichuan Plateau

[Objective] The aim was to lay a foundation for research of contraceptive rodenticide with LDH-C4 as target protein. [ Method] EST sequence of LDH-C gene from black-lipped pika was cloned by PCR with degenerate primers; then the full length open reading frame （ORF） and 3＇UTR sequence were cloned by RACE technique. [ Result] The full length cDNA was 1 498 bp containing an ORF of 996 bp and a 3＇UTR of 486 bp. The ORF encoded a polypeptide of 332 amino acids. The alignment of LDH-C gene ORF nucleotide sequences from different species showed that the gene was conserved even between large taxons. The phylogenic tree showed that black-lipped pika LDH-C was closer to prima- tes and artiodactyla than to rodents. [Conclusion] cDNA sequence of LDH-C gene from black-lipped pika was cloned successfully.

Sequence Analysis of ITS Region of rDNA of Alternaria Nees. from Some Areas of China

[Objective] The study aimed to identify Alternaria Nees from some areas of China at molecular level by analyzing the rDNA ITS sequence. [ Method ] The DNA sequences coding for the 5.8S rDNA and the flanking internal transcribed spacers （ ITS1 and ITS2） were amplified by PCR with universal primers ITS4 and ITS5 and subsequently sequenced for 34 Alternaria isolates from different areas of China. [Result] Sequences analysis showed that 5.8S rDNA was 159 bp and no variation in tested 34 isolates. There had variables sites in ITS. The isolates that had same sequences as A. tenuissima or A. alternata all put up eurytopicity to area and host. The variables sites of the isolates showed the diver- sity of Alternaria in the hosts of Oleaceae, Rosaceae and Solanaceae. At the same time that ITS could not clearly separated the isolates was indicated. The results indicated that the phylogenetic relationship were not closely related to the geographical origin and hosts of these isolates. [ Conclusion] The sequence analysis of ITS region could provide theory basis for the identification of Alternaria Nees..

Molecular Cloning, Sequence Analysis and Prokaryotic Expression of Ovine Activin Receptor Type IIB(ActRIIB) Gene

Objective] This study aimed to clone ovine activin receptor type llB （Ac-tRIIB） gene, construct the prokaryotic expression vector and express the target gene in vitro, thus providing basis for further function verification. [Method] The template cDNA which was reversely transcribed from total RNA of sheep liver tissue, was subjected to polymerase chain reaction （PCR） using specific primers of ActRIIB. The ful-length cDNA of ovine ActRIIB was obtained by pMD18-T cloning and sequencing for bioinformatics analysis. Ovine ActRIIB encoding sequence was subcloned into prokaryotic expression vector pET41a with restriction sites BamHl/Notl, and then transformed into BL21 （DE3）. The induced products by lPTG were analyzed with SDS-PAGE and Western Blot. [Result] The amplified ful-length cDNA of ovine Ac-tRllB gene was 1 564 bp in length （Genbank accession number： JX422071.1） with an open reading frame of 1 539 bp, encoding 512 amino acides. Ovine ActRllB shared the highest homology （99.6%） with bovine ActRllB. ActRllB had highly ho-mologous C-terminal domains and belonged to the TGFβ family. After prokaryotic expression, an approximately 92 kD His-tagged ActRllB recombinant protein was obtained, which was consistent with the excepted result. [Conclusion] Cloning and successful expression of ovine ActRIIB laid solid foundation for further investigation of its biological function.

Cloning and Sequence Analysis of HN and F Protein Genes from a Strain of Goose Paramyxovirus

[ Objective] The study was to clone HN and F genes from GX1 strain of goose paramyxovirus and analyze their sequences. [ Method] According to the full nucleotide sequence of GPV-SF02 strain of goose paramyxovirus, two pairs of pdmers were designed to amplify the HN and F genes from GX1 strain of goose paramyxovirus isolated from diseased goose in Guangxi Zhuang Autonomous Region; the amplified products were ligated into pMD18-T vector and sequenced. [ Result ] HN and F genes of this strain tested were 1 716 and 1 662 bp in full nucleotide length, respectively; both showed the homologues of about 97.3% with GPV- SF02 strain, of 80.3% -97.5% with strains LaSota, F48E9 and JS, of just 84.8% with Miyadera strain. [ Conclusion] The results show that isolated strain BX1 matches to virulent APMV-1 strain, belonging to genotype Ⅶ of APMV-1 strain.

Cloning and Sequence Analysis of Three Plant Ran Genes

[Objective]The aim was to study homology between Ran gene in Allium cepa,Allium sativum and Brassica napus and Ran2 gene in Arabidopsis in order to determine whether three kinds of plant material as substitute for Arabidopsis. [Method]By using RT-PCR method,homology gene was cloned from totoal RNA which extracted from splinter cells of Allium cepa,Allium sativum and Brassica napus with Arabidopsis Ran2 primer,then,carrying out sequence and comparative analysis. [Result]The results showed that the open reading frames of Ran genes in Allium cepa,Allium sativum and Brassica napus were 666,663,666 bp,coding 221,220 and 221 amino acids respectively,with the molecular weight of 24.3 kDa. The sequence analysis showed that the amino acid homology of Ran genes between Allium cepa,Allium sativum,Brassica napus and Arabidopsis Ran2 were respectively 99.1 %,100 % （except an Asp D at Allium sativum C terminal）,96.4 %. The phylogenetic tree indicated that Ran genes from Allium cepa and Allium sativum had closer evolutionary relationship with Arabidopsis Ran2. [Conclusion]The research laid a foundation for further study on the biological function of plant Ran gene.

Sequence Analysis of Mitochondrial DNA D-loop Region in Xinjiang Goose

[Objective] The sequences of mitochondrial DNA D-loop region of Xinjiang Goose with three different colors of plumage were analyzed in order to study the genetic diversity of Xinjiang Goose, as well as the phylogeny and evolution. [Method] Ten geese were selected randomly from the core populations of grey-, mosaic- and white-plumaged Xinjiang Goose respectively with a total number of thirty as experi- mental materials, of which the blood samples were collected from the largest vein under the wing （brachial vein） for DNA extraction. Sequences of mitochondrial DNA D-loop regions were determined using DNA sequencing technology to analyze the polymorphism. In addition, the genetic distances among different populations were estimated through the comparison with the reference sequences. [Resull] The con- tents of A, G, C and T nucleotides in the D-loop region of Xinjiang Goose were 28.85%, 17.05%, 25.38% and 28.72%, respectively. The average haplotype diversity and nucleotide diversity of Xinjiang Goose were 0.583 and 0.056. Xinjiang Goose and Greylag Goose were clustered into the same group. [Conclusion] The results showed that Xinjiang Geese with three different colors of plumage all descend from Greylag Goose （Anser anser）.

Construction of Midgut Tissue-Specific cDNA Library of Bombyx mandarina M. and Isolation and Sequence Analysis of Serine Protease Gene Fragment

[Objective] The aim of the study is to construct cDNA library of midgut tissue of wild silkworm and isolate the serine protease gene. [Method] The midgut tissue-specific cDNA library of wild silkworm was constructed via cDNA Library Construction Kit (TaKaRa), then the serine protease gene was cloned via sequencing of the yielded cDNA library. [Result] The titer of cDNA library reached 6.2×105 pfu/ml, average insert size was about 1.2 kb. The serine protease gene cDNA fragment was obtained from colony sequencing (Accession No: EU672968). The nucleotide sequence of the cloned 854 bp fragment encodes 284 amino acid residues. Homology analyses showed some homology between putative amino acid sequence of the cloned fragment and amino acid sequences of serine proteases from other ten insects. [Conclusion] The results may avail to reveal the resistance of silkworm and wild silkworm to exotic intrusion.

Cloning and Sequence Analysis of Interleukin 10 (IL-10) Full-length cDNA from Cyprinus carpio L.

[Objective] This study aimed to obtain IL-10 (interleukin 10) full-length cDNA of common carp (Cyprinus carpio L.) and conduct the sequence analysis. [Method] The differentially expressed cDNA fragment was obtained by DD-RTPCR (differential display RT-PCR). The cDNA library of peripheral blood leukocytes which were separated from common carp and stimulated by mitogen was screened with a probe labeled with DIG (digoxigenin). The IL-10 full-length cDNA was cloned from 0.8×104 pfu of recombinant phages, and the sequence analysis and homology comparison were carried out. [Result] Sequence analysis indicated that the IL-10 full-length cDNA of common carp was 1 117 bp long, containing a 55 bp 5’-UTR, a 522 bp 3’-UTR, and a 540 bp open reading frame(ORF) encoding 179 amino acids. In addition, there were three mRNA instability motifs (ATTTA) in the 3’-untranslated region. The deduced protein sequence shared typical sequence features of the IL-10 family. Homology comparison indicated that the obtained sequence shared 89.1% homology with the carp IL-10 gene from GenBank. [Conclusion] This study laid foundation for further study of the expression manner, functional characteristic and regulation mechanism of IL-10 in vivo and the interaction mechanism in the inflammatory reaction and immune response.

Development and parentage analysis of SNP markers for Chestnut-vented Nuthatch(Sitta nagaensis)based on ddRAD-seq data

Extra-pair paternity(EPP)is commonly found in socially monogamous birds,especially in small passerine birds,and there are interspecific and intraspecific variations in the extent of EPP.The Chestnut-vented Nuthatch(Sitta nagaensis)is a socially monogamous passerine bird,and verifying whether this species has EPP relies on parentage testing-S.nagaensis is not known to have EPP.In this study,we developed SNP markers of this species that are informative for parentage analysis from double digest restriction site-associated DNA sequencing(ddRAD-seq)data.A panel consisting of 50 SNP markers,with a mean heterozygosity of 0.343,was used to resolve 95% of nestlings to fathers.The combined exclusion probabilities for the first parent and second parent were 0.991 and 0.9999,respectively.This panel of SNP markers is a powerful tool for parentage assignments in S.nagaensis.In addition,we found that three offspring(7.9%)from three nests(23.1%)were the result of extra-pair fertilization out of 38 offspring in 13 nests.Our study provided information on parentage analysis that has not been reported before in S.nagaensis.It also supplemented the understudied EPP behavior of birds in Asia,contributing to a general understanding of the EPP behaviors of birds.

Fine-mapping and primary analysis of candidate genes associated with seed coat color in mung bean(Vigna radiata L.)

Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the seed coat color gene in mung beans would facilitate the development of new varieties and improve their value.In this study,an F2 mapping population consisting of 546 plants was constructed using Jilv9(black seed coat)and BIS9805(green seed coat).Using bulk segregated analysis(BSA)sequencing and kompetitive allele-specific PCR(KASP)markers,the candidate region related to seed coat color was finally narrowed to 0.66 Mb on chromosome(Chr.)4 and included eight candidate genes.Combined transcriptome and metabolome analyses showed that three of the eight candidate genes(LOC106758748,LOC106758747,and LOC106759075)were differentially expressed,which may have caused the differences in flavonoid metabolite content between Jilv9 and BIS9805.These findings can provide a research basis for cloning the genes related to seed coat color and accelerate molecular markerassisted selection breeding in mung beans.