Identifying genetic susceptibility to Aspergillus fumigatus infection using collaborative cross mice and RNA-Seq approach

Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidate genes associated with host susceptibility to Aspergillus fumigatus(Af)using an RNAseq approach in CC lines and hepatic gene expression.Methods:We studied 31 male mice from 25 CC lines at 8 weeks old;the mice were infected with Af.Liver tissues were extracted from these mice 5 days post-infection,and next-generation RNA-sequencing(RNAseq)was performed.The GENE-E analysis platform was used to generate a clustered heat map matrix.Results:Significant variation in body weight changes between CC lines was ob-served.Hepatic gene expression revealed 12 top prioritized candidate genes differ-entially expressed in resistant versus susceptible mice based on body weight changes.Interestingly,three candidate genes are located within genomic intervals of the previ-ously mapped quantitative trait loci(QTL),including Gm16270 and Stox1 on chromo-some 10 and Gm11033 on chromosome 8.Conclusions:Our findings emphasize the CC mouse model's power in fine mapping the genetic components underlying susceptibility towards Af.As a next step,eQTL analysis will be performed for our RNA-Seq data.Suggested candidate genes from our study will be further assessed with a human cohort with aspergillosis.

Research progress on the relationship between Paneth cellssusceptibility genes,intestinal microecology and inflammatory bowel disease

Inflammatory bowel disease(IBD)is a disorder of the immune system and intestinal microecosystem caused by environmental factors in genetically susceptible people.Paneth cells(PCs)play a central role in IBD pathogenesis,especially in Crohn's disease development,and their morphology,number and function are regulated by susceptibility genes.In the intestine,PCs participate in the formation of the stem cell microenvironment by secreting antibacterial particles and play a role in helping maintain the intestinal microecology and intestinal mucosal homeostasis.Moreover,PC proliferation and maturation depend on symbiotic flora in the intestine.This paper describes the interactions among susceptibility genes,PCs and intestinal microecology and their effects on IBD occurrence and development.

Development of RAPD Markers and SCAR Markers Linked to Bentazon Susceptible Lethality Gene in Rice

Rice cultivar Norin 8 and its mutant Norin 8m harbour bentazon resistance trait and bentazon susceptibility trait respectively. A total of 360 arbitrary 10-mer oligonucleotide primers were screened on the genomic DNA of Norin 8 and Norin 8m with RAPD technique. Among which, five primers produced seven polymorphic RAPD bands between Norin 8 and Norin 8m. Amplified RAPD polymorphic products were cloned and sequenced. The sequences were used to design primers for PCR. Five SCAR markers, SCAR/G18/883, SCAR/G18/890, SCAR/G18/919/948, SCAR/D10/1237 and SCAR/F03/1186, were developed from OPG18/943, OPG18/972, OPD10/1248 and OPF03/1198. F-2 progeny of 320 individuals was analyzed to map SCAR markers in relationship to ben or Ben genes. SCAR markers of SCAR/G18/883, SCAR/G18/890, SCAR/G18/919/948 were shown to cosegregate with ben or Ben genes, and SCAR/D10/1237 to be linked of Ben gene with a distance of (14.8 +/- 2.1) cM. The genetic linkage to ben gene and SCAR markers was identified by a pair of near isogenic lines H121 and Hben121. Southern blotting analysis and segregation ratio of F-2 progeny revealed that OPG18/943 and OPG18/972 were single-copy in genome, and locus of OPG18/943 and OPG18/972 were allelic and sequence tagged sites. It is the first report on molecular markers linked to ben or Ben genes. The markers are useful to marker-assisted selection for the breeding and tag ben gene with map-based cloning.

The relation between HLA-DQA1 genes and genetic susceptibility to duodenal ulcer in Wuhan Hans

AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wascarried out by digesting the locus specificpolymerase chain reaction amplified productswith alleles specific restriction enzymes(PCR-RFLP),i.e.,Apal Ⅰ,Bsaj Ⅰ,Hph Ⅰ,Fok Ⅰ,Mbo Ⅱ and Mnl Ⅰ.RESULTS The allele frequencies of DQA1 * 0301and DQA1 * 0102 in patients with duodenal ulcerwere significantly higher and lower respectivelythan those in healthy controls(0.40 vs 0.20,P = 0.003,mcorret = 0.024)and(0.05 vs 0.14,P = 0.012,but Pcorret】0.05),respectively.CONCLUSION DQA1 * 0301 is a susceptiblegene for duodenal ulcer in Wuhan Hans,andthere are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients andhealthy controls.

The relationship of Imp2 and DR3 genes with susceptibility to type Ⅰ diabetes mellitus in south China Han population

AIN To study the relationship of Imp2 and DR3genes with type Ⅰ diabetes mellitus.NETHODS Imp2 genotypes and DR3 wereidentified in 68 patients with type Ⅰ diabetesmellitus(Ⅰ-DM)and 71 healthy controls.Then,Ⅰ-DM patients and controls were respectivelyallocated into DR3-positive and DR3-negativegroups.The frequencies of Imp2 and DR3 genein random subjects,and Imp2 genotypes in DR3-matched subjects were compared between Ⅰ-DMpatients and controls.At the same time,Ⅰ-DMpatients were divided into 3 groups based on theonset age of diabetics:group A≤14 years,group B 15-30 years and group C≥31 years.RESULTS The frequency of DR3 in Ⅰ-DMpatients was significantly higher than that incontrols(47% vs 21%,P【0.005),and it wassignificantly higher in group A than that in groupB+C(70% vs 36%,x^2=7.07,P【0.01).Therewas a significant difference among groups withdifferent onset age of diabetics(x^2=8.19,rp=0.33,P【0.05).In random subjects,thefrequency of Imp2.R/R in Ⅰ-DM patients waslower(43% vs 61%,P【0.05)and Imp2.R/Hhigher(53% vs 28%,P【0.05)than that incontrols,and there was no significant differenceamong groups with different onset age ofdiabetics.In DR3-positive subjects,thefrequency of Imp2.R/R in Ⅰ-DM patients waslower(47% vs 87%,P【0.05)and Imp2-R/H higher(47% vs 13%,P【0.05)than that incontrols.In DR3-negative subjects,thefrequency of Imp2.R/H in Ⅰ-DM patients washigher than that in controls(58% vs 32%,P【0.01),but the frequency of Imp2-R/R and Imp2H/H was not significantly different betweenthese two groups.CONCLUSION DR3 gene may be one of thesusceptible genes of Ⅰ-DM,and significantlyrelated to the onset age of diabetics,and thepersons with DR3 may have an younger onsetage of diabeteS.The Imp2-R/R may be theprotective genotype of Ⅰ-DM,and Imp2-R/H thesusceptible genotype.These were not affectedby DR3 gene.Imp-2 genotypes were not relatedwith the onset age of diabetics.

AFLP Marker Linked to Turnip Mosaic Virus Susceptible Gene in Chinese Cabbage(Brassica rapa L.ssp.pekinensis)

Turnip mosaic virus (TuMV) which has several strains causes the most important virusdisease in Chinese cabbage in terms of crop damage. In China, Chinese cabbage is infectedby a mixture of strains, breeding of cultivar for the TuMV resistance has become themajor aim. Screening the molecular marker linked to the TuMV-resistance gene formolecular assisted selection is the major method to improve the breeding efficiency. Inthis study, we used AFLP technique and the method of bulked segregant analysis(BSA) tostudy the progeny of Brp0058Brp0108, and identified two DNA molecular marker linked toTurnip mosaic virus-resistance gene with a recombination frequency 7.5 cM and 8.4 cM.

Association between 15 known or potential breast cancer susceptibility genes and breast cancer risks in Chinese women

Objective:There are many hereditary breast cancer patients in China,and multigene panel testing has been a new paradigm of genetic testing for these patients and their relatives.However,the magnitude of breast cancer risks related to multiple breast cancer susceptibility genes are largely unknown in Chinese women.Methods:We screened pathogenic variants in 15 established or potential breast cancer susceptibility genes from 8,067 consecutive Chinese female breast cancer patients and 13,129 Chinese cancer-free female controls.These breast cancer patients were unselected for age at diagnosis or family history.Results:We found that pathogenic variants in TP53[odds ratio(OR):16.9,95%confidence interval(CI):5.2–55.2];BRCA2(OR:10.4,95%CI:7.6–14.2);BRCA1(OR:9.7,95%CI:6.3–14.8);and PALB2(OR:5.2,95%CI:3.0–8.8)were associated with a high risk of breast cancer.ATM,BARD1,CHEK2,and RAD51D were associated with a moderate risk of breast cancer with ORs ranging from 2-fold to 4-fold.In contrast,pathogenic variants of NBN,RAD50,BRIP1,and RAD51C were not associated with increased risk of breast cancer in Chinese women.The pathogenic variants of PTEN,CDH1,and STK11 were very rare,so they had a limited contribution to Chinese breast cancer.Patients with pathogenic variants of TP53,BRCA1,BRCA2,and PALB2 more often had earlyonset breast cancer,bilateral breast cancer,and a family history of breast cancer and/or any cancer.Conclusions:This study provided breast cancer risk assessment data for multiple genes in Chinese women,which is useful for genetic testing and clinical management of Chinese hereditary breast cancer.

Fine mapping and characterization of stripe rust resistance gene YrAYH in near-isogenic lines derived from a cross involving wheat landrace Anyuehong

Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease in wheat worldwide.Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs.In this study,we fine-mapped and characterized a stripe rust resistance gene,YRAYH,on chromosome arm 5BL in the Chinese wheat landrace Anyuehong(AYH).Evaluations of stripe rust response to prevalent Chinese Pst races in near-isogenic lines derived from a cross of Anyuehong and Taichung 29 showed that YrAYH conferred a high level of resistance at all growth stages.Fine mapping using a large segregating population of 9748 plants,narrowed the YRAYH locus to a 3.7 Mb interval on chromosome arm 5BL that included 61 annotated genes.Transcriptome analysis of two NIL pairs identified 64 upregulated differentially expressed genes(DEGs)in the resistant NILs(NILs-R).Annotations indicated that many of these genes have roles in plant disease resistance pathways.Through a combined approach of fine-mapping and transcriptome sequencing,we identified a serine/threonine-protein kinase SRPK as a candidate gene underlying YrAYH.A unique 25 bp insertion was identified in the NILs-R compared to the NILs-S and previously published wheat genomes.An InDel marker was developed and co-segregated with YrAYH.Agronomic trait evaluation of the NILs suggested that YrAYH not only reduces the impact of stripe rust but was also associated with a gene that increases plant height and spike length.

An Investigation of the Effects of B7-H4 Gene rs10754339 and miR-125a Gene rs12976445 on Cancer Susceptibility

Objective To investigate the effects of the B7-H4 gene rs10754339 and miR-125a gene rs12976445 on cancer susceptibility through a case-control study and meta-analysis.Methods A total of 1,490 cancer patients(lung/gastric/liver/:550/460/480)and 800 controls were recruited in this case-control study.The meta-analysis was performed by pooling the data from previous related studies and the present study.Results The results of this study showed that in the Hubei Han Chinese population,the rs10754339gene was significantly associated with the risk of lung and gastric cancer but not liver cancer,and the rs12976445 gene was significantly associated with the risk of lung cancer but not liver or gastric cancer.The meta-analysis results indicated that rs10754339 and rs12976445 contributed to cancer susceptibility in the Chinese population and also revealed a significant association between rs10754339and breast cancer risk,as well as between rs12976445 and lung cancer risk.Conclusion The B7-H4 gene rs10754339 and miR-125a gene rs12976445 may be the potential genetic markers for cancer susceptibility in the Chinese population,which should be validated in future studies with larger sample sizes in other ethnic populations.

SCAR Markers Assisted Selection for a Bentazon Susceptible Lethality Gene (ben) in Rice

In progenies resulting from crosses involving rice cultivar Norin 8m susceptible to bentazon as the donor of ben gene, SCARs tightly linked to ben were utilized for selection of ben. The homozygous and heterozygous genotypes with ben could be identified with the SCARs. The molecular markers offer a powerful tool for indirect selection of ben and can accelerate the introgression of ben into current rice cultivars.

Differential expression analysis of coronary heart disease related genes in Hainan residents

Objective:To explore the correlation between coronary heart disease related genes and coronary heart disease in hospitalized patients in Hainan,and to provide theoretical basis for enriching the screening methods of high-risk groups of coronary heart disease in Hainan,and optimizing the prevention and treatment strategies.Methods:We select hospitalized patients born in Hainan and aged>30 years old from the Second Affiliated Hospital of Hainan Medical Unversity between January 1,2020 and June 30,2022,and divided the patients into the coronary heart disease group and the non-coronary heart disease group.PCR real-time fluorescence was used to measure gene expression,and Spearman correlation analysis was used to explore the correlation between gene expression and coronary heart disease.Results:A total of 55 whole blood samples were collected from non-coronary heart disease patients(including 26 women and 29 men),with a median age of 57 years,and 170 whole blood samples from coronary heart disease patients(including 44 women and 126 men),with a median age of 63.17.Apolipoprotein B gene(ApoB)was highly expressed in patients with coronary heart disease(P<0.001);AGT gene(P=0.0158),ApoE gene(P=0.0126),FGB gene(P=0.005),GNB gene(P=0.0151),MTFHR gene(P=0.0119),SEL gene(P=0.005),TNF gene(P=0.0298)were significantly overexpressed in the non-coronary heart disease group.The expression of NOS3 gene(P=0.3047),IL6 gene(P=0.7239),ACE gene(P=0.7852)was not different between the two groups.Coronary heart disease was negatively correlated with AGT gene(r=-0.163,P=0.011,P<0.05),positively correlated with APOB gene(r=0.75,P=0,P<0.01),negatively correlated with FGB gene(r=-0.163,P=0.011,P<0.05),negatively correlated with GNB gene(r=-0.165,P=0.011,P<0.05),negatively correlated withSEL gene(r=-0.171,P=0.007,P<0.01),negatively correlated with MHTHR gene(r=-0.210,P=0.001,P<0.01)and negatively correlated with TNF gene(r=-0.131,P=0.04,P<0.05),but coronary heart disease was not correlated with APOE,NOS3,ACE,IL6 and other genes(P>0.05).The ApoB gene of coronary heart disease was negatively correlated with triglyceride(r=-0.461,P=0),positively correlated with age(r=0.173,P=0.009),positively correlated with total cholesterol(r=0.499,P=0),negatively correlated with high-density lipoprotein(r=-0.181,P=0.007),and negatively correlated with low-density lipoprotein(r=-0.143,P=0.031).Conclusion:(1)The detection of apolipoprotein B gene expression may be used as an indicator for screening coronary heart disease in the coronary population in Hainan.It may increase the risk of coronary heart disease by affecting the level of total cholesterol.A larger sample of research is still needed.(2)AGT,ApoE,FGB,GNB,MTFHR,SELE,TNF and other genes may be the protective genes of non-coronary heart disease population in Hainan,and the high expression of these genes may reduce the occurrence of coronary heart disease,which still needs further study.

Antibiotic susceptibility and molecular characterization of resistance genes among Escherichia coli and among Salmonella subsp. in chicken food chains

Objective: To investigate the occurrence of resistance genes among Escherichia coli(E. coli) and Salmonella subsp. isolated in chicken food chains in Phnom Penh, 2012–2013.Methods: Six hundred eighty two E. coli and 181 Salmonella Albany, Corvallis, and Kentucky strains were examined for susceptibilities to eight antimicrobials and following resistance genes were identified by PCR: blaTem, Str A, aad A, sul1, sul2, gyr A, Tet(A), and Tet(B).Results: E. coli presented high resistances to tetracycline, amoxicillin, and sulfamethoxazole(63.1%–76.1%). Salmonella Albany and Salmonella Kentucky traduced high resistance percentages to amoxicillin, tetracycline, sulfamethoxazole, and nalidixic acid(84.6%–100%). Among amoxicillin-resistant isolates, blaTemgenes were observed for 62% of E. coli isolates and 20% of 65 Salmonella Kentucky. The Str A gene was prevalent in 36% of 331 aminoglycoside-resistant E. coli and 90% of 40 aminoglycoside-resistant Salmonella Corvallis. The sul2 gene was predominant among sulfamethoxazole-resistant isolates, for 56% of 431 E. coli and 53% of 66 Salmonella Corvallis; the sul1 gene was observed in 54% of Salmonella Albany. The Tet(A) resistance gene was prevalent in E.coli(86%), Salmonella Corvallis(82%), Salmonella Kentucky(84%). High percentages of gyr A genes observed among nalidixic-acid resistant E. coli(91%), Salmonella Albany(92%), Salmonella Corvallis(75%) and Salmonella Kentucky(85%).Conclusions: Important occurrences of resistance gene were observed among E. coli and Salmonella in chicken food chains in Cambodia.

A Comprehensive Study of the Association between LEPR Gene rs1137101 Variant and Risk of Digestive System Cancers

Objective The leptin receptor,encoded by the LEPR gene,is involved in tumorigenesis.A potential functional variant of LEPR,rs1137101(Gln223Arg),has been extensively investigated for its contribution to the risk of digestive system(DS)cancers,but results remain conflicting rather than conclusive.Here,we performed a case–control study and subsequent meta-analysis to examine the association between rs1137101 and DS cancer risk.Methods A total of 1,727 patients with cancer(gastric/liver/colorectal:460/480/787)and 800 healthy controls were recruited.Genotyping of rs1137101 was conducted using a polymerase chain reactionrestriction fragment length polymorphism(PCR-RFLP)assay and confirmed using Sanger sequencing.Twenty-four eligible studies were included in the meta-analysis.Results After Bonferroni correction,the case–control study revealed that rs1137101 was significantly associated with the risk of liver cancer in the Hubei Chinese population.The meta-analysis suggested that rs1137101 is significantly associated with the risk of overall DS,gastric,and liver cancer in the Chinese population.Conclusion The LEPR rs1137101 variant may be a genetic biomarker for susceptibility to DS cancers(especially liver and gastric cancer)in the Chinese population.

Isolation,identification,and virulence gene analysis of pathogenic Aeromonas dhakensis in Macrobrachium rosenbergii and histopathological observation

To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.

Correlation between single nucleotide polymorphism of rs3811047 in IL-1 F7 gene and rheumatoid arthritis susceptibility among Han population in central plains of China

Objective:To discuss the association between single nucleotide polymorphism(SNP) of rs3811047 in IL-1 F7 gene and rheumatoid arthritis(RA) susceptibility among the Han population in central plains of China.Methods:A total of 276 RA patients admitted to our hospital from December 2009 to December 2011 together with 276 healthy physical examinees in the same period were chosen as the subjects.The typing for rs3811047 SNP in IL-1 F7 gene was carried out by using ligase detection reaction and polymerase chain reaction technique.And the frequency of each allele and genotypes distribution was calculated so as to evaluate the association between genotype distribution and RA susceptibility.Results:The frequency of A allele of rs3811047 in IL-1 F7 gene in RA group and control group was 16.27%and 17.68%,respectively,and that of G allele in two groups was 83.73%and 82.32%,respectively.The difference between two groups wasn’t statistical significant(P 】0.05).The frequency of genotype AA,AG and GG in RA group was 2.19%,27.84%and 69.97%,respectively,while that in control group was 2.94%,29.78%and 67.28%, respectively.The difference of distribution of three genotypes was not statistically significant (P 】0.05).RA patients with A allele were better than those without A allele in joint swelling index, rest pain,HAQ scoring and blood sedimentation.There was significant difference between two groups in above indexes(P【0.05/P【0.01).Conclusions:No significant correlation between RA susceptibility among the Han population in central plains of China and rs3811047 SNP inIL-1 F7 gene is observed.However,A allele of rs3811047 has certain influence on the condition of RA patients.

Genetics of non-alcoholic fatty liver disease: From susceptibility and nutrient interactions to management

Genetics plays an important role in determining the susceptibility of an individual to develop a disease. Complex, multi factorial diseases of modern day(diabetes, cardiovascular disease, hypertension and obesity) are a result of disparity between the type of food consumed and genes, suggesting that food which does not match the host genes is probably one of the major reasons for developing life style diseases. Non-alcoholic fatty liver is becoming a global epidemic leading to substantial morbidity. While various genotyping approaches such as whole exome sequencing using next generation sequencers and genome wide association studies have identified susceptibility loci for non-alcoholic fatty liver disease(NAFLD) including variants in patatin-like phospholipase domain containing 3 and transmembrane 6 superfamily member 2 genes apart from others; nutrient based studies emphasized on a combination of vitamin D, E and omega-3 fatty acids to manage fatty liver disease. However majority of the studies were conducted independent of each other and very few studies explored the interactions between the genetic susceptibility and nutrient interactions. Identifying such interactions will aid in optimizing the nutrition tailor made to an individual's genetic makeup, thereby aiding in delaying the onset of the disease and its progression. The present topic focuses on studies that identified the genetic susceptibility for NAFLD, nutritional recommendations, and their interactions for better management of NAFLD.

The Alzheimer's disease-associated gene TREML2 modulates inflammation by regulating microglia polarization and NLRP3 inflammasome activation

Triggering receptor expressed on myeloid cells-like 2(TREML2)is a newly identified susceptibility gene for Alzheimer's disease(AD).It encodes a microglial inflammation-associated receptor.To date,the potential role of mic roglial TREML2 in neuroinflammation in the context of AD remains unclear.In this study,APP/PS1 mice were used to investigate the dynamic changes of TREML2 levels in brain during AD progression.In addition,lipopolysaccharide(LPS)stimulation of primary microglia as well as a lentivirus-mediated TREML2 overexpression and knockdown were employed to explore the role of TREML2 in neuroinflammation in the context of AD.Our res ults show that TREML2 levels gradually increased in the brains of AP P/PS1 mice during disease progression.LPS stimulation of primary microglia led to the release of inflammato ry cytokines including interleukin-1β,inte rleukin-6,and tumor necrosis factor-a in the culture medium.The LPS-induced mic roglial release of inflammatory cytokines was enhanced by TREML2 overexpression and was attenuated by TREML2 knoc kdown.LPS increased the levels of mic roglial M1-type polarization marker inducible nitric oxide synthase.This effect was enhanced by TREML2 overexpression and ameliorated by TREML2 knockdown.Furthermore,the levels of microglial M2-type polarization markers CD206 and ARG1 in the primary microglia were reduced by TREML2 overexpression and elevated by TREML2 knockdown.LPS stimulation increased the levels of NLRP3 in primary microglia.The LPS-induced increase in NLRP3 was further elevated by TREML2 overexpression and alleviated by TREML2 knockdown.In summary,this study provides the first evidence that TREML2 modulates inflammation by regulating microglial polarization and NLRP3 inflammasome activation.These findings reveal the mechanisms by which TREML2 regulates microglial inflammation and suggest that TREML2 inhibition may represent a novel therapeutic strategy for AD.

Current status of the genetic susceptibility in attenuated adenomatous polyposis

Adenomatous polyposis(AP)is classified according to cumulative adenoma number in classical AP(CAP)and attenuated AP(AAP).Genetic susceptibility is the major risk factor in CAP due to mutations in the known high predisposition genes APC and MUTYH.However,the contribution of genetic susceptibility to AAP is lower and less understood.New predisposition genes have been recently proposed,and some of them have been validated,but their scarcity hinders accurate risk estimations and prevalence calculations.AAP is a heterogeneous condition in terms of severity,clinical features and heritability.Therefore,clinicians do not have strong discriminating criteria for the recommendation of the genetic study of known predisposition genes,and the detection rate is low.Elucidation and knowledge of new AAP high predisposition genes are of great importance to offer accurate genetic counseling to the patient and family members.This review aims to update the genetic knowledge of AAP,and to expound the difficulties involved in the genetic analysis of a highly heterogeneous condition such as AAP.

Physical Location of HelminthosporiumCarbonum Susceptibility Gene hm1 by FISH of a RFLP Marker umc119 in Maize

A fluorescencein situ hybridization (FISH) procedure was adopted to physically map a RFLP marker, umc119 near the centromere of the long arm of linkage group1 in maize. The hm1 gene (Helminthosporium carbonum susceptibility gene) was linked closely with the marker umc119. RFLP markers are very good landmarks for mapping genes. Therefore, we also determined the position of the gene hm1 on the chromosome based on the physical location of umc119. The disease induced by infection ofHelminthosporium carbonum is one of the serious maize diseases and it distributes in many countries including China. Hybridization sites were showed on 1 L (long arm of chromosome1) and 5 L. The percentage distance from centromere to the hybridization site was 22.86 on 1 L and 58.23 on 5 L the detection rate was about 12% for mitotic cells. In interphase nuclei five hybridized sites were detected. It demonstrated that umc119 was multiplicated sequences. FISH has more advantages overin situ hybridization (ISH) detected by DAB for increasing the detection ratio and contrast between chromosomes and hybridization signals. The ability to detect the hybridization signal of a small low copy DNA sequence is a very important key towards wide application of FISH for plant genome mapping.

The Association between RASSF1 Gene Polymorphisms and Lung Cancer Susceptibility among People in Hubei Province of China

The relationship between Ala/Ser polymorphism in 133 codon of exon 3 region of the RASSF1 gene and genetic susceptibility of lung cancer in Hubei province Han population was investigated by a case-control study. Polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） technique was adopted to analyze the polymorphism of codon 133 of exon 3 in the RASSF1 gene of 100 pathologically diagnosed lung cancer patients, and 100 healthy controls. The relationship between different genotypes and the susceptibility of lung cancer was analyzed. Among 200 blood samples from Han people in Hubei Province, including 100 from lung cancer patients and 100 from healthy controls, the frequencies of Ala/Ala, Ala/Ser, Ser/Ser genotype of the RASSF1 in lung cancer patients were 83%, 16%, 1%, and those in healthy controls was 93%, 7%, 0% respectively, with the difference being statistically significant between two groups （P〈0.05）. The individuals with Ala/Ser genotype had higher risk of suffering from lung cancer, with an OR of 2.341, and 95% CI of 1.009-6.393 respectively. It was concluded that RASSF1Ala133Ser was a susceptible genetic factor of lung cancer. Ala/Ser genotype increased the risk of lung cancer.