ABSTRACT
Anencephaly and myelomeningocele are the 2 most common forms of neural tube defects (NTDs). During embryogenesis large numbers of extrinsic and intrinsic factors are responsible for the closing of the neural tube. "Stem cells" maintain the pluripotency during differentiation of 3 germ layers, including the neural ectoderm. We examined the role of Oct4, Nanog3, and Sox2 genes in the etiopathology of NTDs in an eastern Indian population using PCR-based DNA analysis. The highest frequency (16%) of complete loss of the Sox2 gene was found in NTDs. The highest frequency (48%) of overexpression (upregulation) was found for Nanog3, while 40% was observed for Oct4 and Sox2. The odds ratio for cases versus controls was from 0.132 at 95% confidence interval = 0.005-1.298 for Nanog3 to 2.316 (0.424-13.812) for Oct4. The highest frequency (77%) of overexpression for Nanog3 and Sox2 was observed in encephalocele and anencephalic patients, while in the comparison of regional variation, i.e., cephalic to caudal regions of NTDs, the highest frequency of downregulation (regression) of Nanog3 and Sox2 was found in lumbosacral myelomeningocele patients. However, cervical myelomeningocele patients had the highest frequency of overexpression in all 3 genes, suggesting that the mutational spectra of stem cells influence the cells of the neural crest in NTDs.
Subject(s)
Neural Tube Defects/genetics , Population/genetics , Stem Cells/classification , Biomarkers/metabolism , Case-Control Studies , Gene Frequency , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , India , Infant , Infant, Newborn , Mutation , Nanog Homeobox Protein , Octamer Transcription Factor-3/genetics , Octamer Transcription Factor-3/metabolism , SOXB1 Transcription Factors/genetics , SOXB1 Transcription Factors/metabolism , Stem Cells/metabolismABSTRACT
Cystathionine beta synthase gene (CßS) catalyzes the condensation of homocysteine with serine, forming cystathionine by the transsulfuration pathway. Disruption of CßS enzyme activity due to defective folic acid metabolism increases the risk factor for neural tube defects. We evaluated the CßS gene mutation in 25 children with neural tube defects (NTDs), including lumbosacral and thoracic myelomeningocele and open NTDs and mothers of cases, along with 25 healthy children and their mothers, serving as controls. Genomic DNA was isolated to assess the polymorphism of 852Ins68 in the CßS gene using PCR-RFLP analysis and nucleotide sequencing techniques. The 68-bp insertion was observed in one of the 25 NTD cases (lumbosacral myelomeningocele), and in two of the mothers of NTD cases. Statistical analysis was carried out using the Fischer exact probability test, which showed a lack of significance (P > 0.05), but the odds ratio of 2.08 with 95% confidence interval of 0.17-24.6 in NTDs mother was quite high because of the small sample size. However, the study was further extended to find out the involvement of specific nucleotide sequences, which again confirmed the 852Ins68 insertion and replacement of nucleotides (TCCAT to GGGG) in lumbosacral myelomeningocele (due to other category of NTDs), suggesting that it could be an independent risk factor for birth defects, including NTDs.
Subject(s)
Cystathionine beta-Synthase/genetics , Meningomyelocele/genetics , Mutagenesis, Insertional , Neural Tube Defects/genetics , Polymorphism, Restriction Fragment Length , Adult , Child, Preschool , Cystathionine beta-Synthase/metabolism , Female , Humans , India/epidemiology , Infant , Infant, Newborn , Male , Meningomyelocele/enzymology , Meningomyelocele/epidemiology , Neural Tube Defects/enzymology , Polymerase Chain Reaction/methods , Prevalence , Risk FactorsABSTRACT
Infertility is a major reproductive health threat; the frequency of male infertility due to Y-chromosome microdeletions is 13-18% in the human population; these microdeletions involve recurrent loss of three non-overlapping regions designated as AZFa, AZFb and AZFc, associated with spermatogenic failure. Several contradictory reports have been published regarding deletion frequency based on sequence-tagged site markers and genotype-phenotype correlation. We examined the prevalence of Yq- deletion in 64 clinically diagnosed infertile male patients. We found a 3% frequency of microdeletion of the AZFc region; hormone profiles (FSH, LH and testosterone) showed significantly (P < 0.001) elevated levels compared to controls. No mutations were observed in the AZFa and AZFb regions, perhaps due to the selective use of sequence-tagged site markers.
Subject(s)
Chromosome Deletion , Chromosomes, Human, Y/genetics , Infertility, Male/genetics , Seminal Plasma Proteins/genetics , Adult , DNA Primers/genetics , Genetic Loci , Genetic Markers , Humans , Male , Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Tagged SitesABSTRACT
Fourteen Azospirillum brasilense strains growing at a sub-optimum temperature were selected based on their ability to grow and carry out plant growth promoting activities at 22 degrees C. The strains were tested for their response to inoculation in wheat (two popular cultivars, HD2285 and WH547, under sterile conditions) crop using sterile and nonsterile rooting medium. Significant increase in plant growth parameters was observed; the overall response to inoculation was better in cultivar HD2285. Based on their performance under sterile conditions, 4 strains were selected and compared under nonsterile conditions with strain sensitive to a sub-optimum temperature in pots using wheat variety HD2285. The strains capable of growing at the sub-optimum temperature can colonize the wheat endorhizosphere efficiently and improve the plant growth and yield as compared to sensitive strain; a 25-27% increase in grain yield was found on inoculating two selected strains compared to NO3- control.