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At least 595 records · Page 33Linked to original sources
PubMed1989

Restriction fragment length polymorphisms associated with growth hormone and prolactin genes in Holstein bulls: evidence for a novel growth hormone allele.

Sperm DNA isolated from sons of three extensively used US Holstein bulls was screened for differences associated with the primary gene structure of the bovine growth hormone (bGH) and prolactin (bPrl) genes. Southern blot analysis of DNA digested with 10 restriction enzymes revealed that offspring from two of the three bull families exhibited polymorphisms around the bGH and bPrl genes. Restriction fragment length polymorphisms (RFLPs) around the bGH gene were detected with five enzymes, whereas three enzymes revealed RFLPs around the bPrl gene. At least three structural differences were predicted around the bGH gene. The most common variant hybridization pattern appeared to involve an insertion/deletion located downstream of the conserved 3' EcoRI site. The presence of RFLPs in the genes coding for these pituitary hormones within a familial line may provide the basis for genetic markers associated with lactation and mammary development.

Alleles↗
PubMed1994

Restriction fragment length polymorphism of the human CYP2E1 (cytochrome P450IIE1) gene and susceptibility to lung cancer: possible relevance to low smoking exposure.

Polymorphic metabolism of certain chemical carcinogens may result in differences in susceptibility to cancers. Human CYP2E1 (cytochrome P450IIE1) is an enzyme involved in the metabolic activation of precarcinogens such as nitrosamines. We detected a restriction fragment length polymorphism (RFLP) of the human CYP2E1 gene for the restriction endonuclease Dra I. The distribution of this polymorphism was examined among lung cancer patients (n = 91), patients with cancer of the digestive tract (n = 45) and controls (n = 76). A significant difference in the distribution was observed between lung cancer patients and controls (chi 2 = 11.4 with 2 df; p < 0.005). On the other hand, there was no significant difference between patients between cancer of the digestive tract and controls (chi 2 = 4.87 with 2 df; NS). This finding suggests that the Dra I polymorphism of the CYP2E1 gene is associated with susceptibility to lung cancer. In addition, an association was found between the amount of lifelong smoking exposure and the distribution of the genotypes of the RFLP among lung cancer patients. The distribution pattern seemed deviated from that of controls especially in the population of low smoking exposure. Our Northern blot analysis data using RNA from human liver autopsy samples suggest that the Dra I polymorphism might be associated with the gene expression of CYP2E1 at mRNA level.

Aged↗
PubMed1985

Use of restriction fragment length polymorphisms to determine the clonal origin of human tumors.

A novel strategy to determine the clonal origin of human tumors has been devised. The strategy involves the use of a cloned polymorphic X-chromosomal gene and two restriction endonucleases. The first endonuclease distinguishes the paternal and maternal copies of the gene through a DNA polymorphism of restriction fragment length. The second endonuclease distinguishes active from inactive copies of this gene through changes in DNA methylation. As illustrations of this strategy, three human cancers were each shown to be monoclonal. The analysis described should have a wide variety of clinical and experimental applications.

Autoradiography↗
PubMed1988

Restriction fragment length polymorphisms in the ETS-1 proto-oncogene. Comparison of Saudi and Western populations.

We have cloned part of the ETS 1 proto-oncogene and demonstrated the presence of two polymorphic Sst I restriction sites. A probe derived from one of our clones revealed the presence of 8.3 kb, 9.5 kb and/or 11.5 kb fragments on Southern blots of human DNA samples. The relative frequencies of these alleles appear to be significantly different between Saudi and Western populations, but there are no apparent differences in these frequencies between Saudi non-leukemic and leukemic individuals.

Alleles↗
PubMed1991

Restriction fragment length polymorphism of a bovine T-cell receptor beta gene.

Genetic polymorphism of a bovine T-cell receptor beta gene was investigated by analysing restriction fragment length polymorphism (RFLP). One locus, denoted TCRB, with four allelic variants was revealed. The relationship between alleles at the TCRB locus and bull breeding values for disease and milk production was investigated in a sample of 196 progeny-tested AI bulls of the Swedish Red and White breed. The statistical evaluation of the data revealed no convincing association between TCRB alleles and any of the traits studied.

Alleles↗
PubMed1991

HLA-DRw11, DQw7 has four cellular subtypes revealed by homozygous typing cells and undetected by restriction fragment length polymorphism.

HLA-DRw11 is in strong linkage disequilibrium with DQw7. We have investigated the heterogeneity of DRw11, DQw7 by cellular typing and by HLA cDNA probes. The results obtained by local and other homozygous typing cells in four informative Caucasoid families and 20 genotyped individuals demonstrate the existence of at least four different cellular subtypes. The frequency of DRw11, DQw7 is 25.7% with the following distribution of subtypes: Dw5 (17.3%), JAC (4.2%), JVM (2.8%), TIS (0.7%), and blank (0.7%). JVM (10W 9039) has been previously described; TIS (10W 9042) and JAC are postulated new specificities from our laboratory. None of these subtypes typed for DRw11, DQw1 cells. The cellular heterogeneity contrasts with the absence of polymorphism observed by serology and by restriction fragment length polymorphism after hybridization with DRB, DQA, and DQB probes. Variation in amino acids of the DRB1 chain has been reported for at least three variants: Dw5, JVM, and TIS (more recently).

Amino Acid Sequence↗
PubMed1991

Membrane cofactor protein of the complement system. A HindIII restriction fragment length polymorphism that correlates with the expression polymorphism.

An RFLP was found in the DNA of 25 unrelated persons, two families, and five cell lines that correlated with their membrane cofactor protein phenotype. If restricted with HindIII, DNA derived from upper band predominant protein (U) phenotypes had a band at 2 kb, whereas DNA of lower band predominant (L) phenotypes had a 4-kb band. The equal band protein phenotype, in which equal quantities of the two species are expressed, had bands at both 4 and 2 kb. The polymorphic HindIII site was localized to an intron within the membrane cofactor protein gene between exon 1 (codes for 5'UT/signal peptide) and exon 2 (codes for the first short consensus repeat). Using the polymerase chain reaction (PCR), sequences around this site were amplified and a single band of 260 bp was produced. In the U phenotype, the PCR product was restricted with HindIII into 200- and 60-bp fragments. In the L phenotype, there was no change in the size of 260 bp upon restriction with HindIII. For the equal band protein phenotype, the PCR product was partially cleaved. The 260-bp PCR product was subcloned and sequenced. DNA from the U phenotype demonstrated an intact HindIII site (AAGCTT), whereas in the DNA of the L phenotype, this site was altered because a "G" was substituted for a "C" (AAGGTT).

Alleles↗