Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.5.7.1 (methylenetetrahydrofolate reductase)
 2,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fluorescein-labeled oligonucleotide probes can be used to continuously monitor the polymerase chain reaction. Depending on the sequence, the fluorescence intensity of the probe is either increased or decreased by hybridization. The greatest effect is probe quenching by hybridization to amplicons containing deoxyguanosine nucleotides (Gs), giving a sequence-specific decrease in fluorescence as product accumulates. Quenching of the probes by Gs is position dependent. A 25% decrease in fluorescence of 5'-labeled probes was observed with a G at the first position of the 3'-dangling end. Additional Gs can increase quenching to about 40%. This change in fluorescence with hybridization allows real-time quantification and mutation detection with a simple single labeled probe. Quantification of the initial template copy number is possible by monitoring fluorescence at each cycle at a constant temperature. Mutation detection by Tm estimates from melting curve analysis for factor V Leiden, hemoglobin C, hemoglobin S, the thermolabile mutation of methylenetetrahydrofolate reductase, and the cystic fibrosis-associated deletion F508del is demonstrated. By using the inherent quenching of deoxyguanosine nucleotides in the amplicon, complicated probe designs involving internal quenching can be avoided.
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PMID:Fluorescein-labeled oligonucleotides for real-time pcr: using the inherent quenching of deoxyguanosine nucleotides. 1118 Sep 41

The causes of spermatogenetic failure found in most cases of non-ohstmctive azoospermia or severe oligospermia remain largely unclear. It is estimated that in about 30% of the cases, male infertility is due to genetic causes, including chromosomal abnormalities, Y chromosome microdeletions, gene mutations, etc. Klinefelter's syndrome and microdeletions in the Y chromosome long arm (Yq) represent the most frequent molecular genetic cause of severe infertility. Gene mutations involved in male infertility include the cystic fibrosis transmembrane conductance regulator (CFTR) gene, androgen receptor (AR) gene, insulin-like factor 3 (INSL3) gene and leucine-rich repeat-containing G-protein coupled receptor 8 (LGR8) gene. CFTR mutations cause cystic fibrosis, absence of vas deferens and non-obstructive azoospermia. The AR gene mutations are responsible for the androgen insensitivity syndrome and spermatogenetic damage. And INSL3 and LGR8 gene mutations have been associated with abnormalities in testis descent and cryptorchidism. Meta-analyses have revealed a significant association between the polymorphism and male infertility only for partial AZFc deletion, CAG repeat length in the AR gene and methylenetetrahydrofolate reductase (MTHFR) gene. This paper mainly reviews the genetic causes of male infertility and the genetic polymorphisms possibly associated with male infertility.
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PMID:[Genetic causes of male infertility]. 1900 17