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Biomedical subjects

F Tata

Publications and source records attributed to F Tata.

15 recordsLinked to original sources
PubMed2000

Homeobox genes and gut development.

The gut of vertebrates exhibits a common anteroposterior regional differentiation. The role of homeobox genes in establishing this pattern is inferred by their sites of expression. It is suggested that the primary source of positional information is in the endoderm, which subsequently establishes a 'dialogue' with the surrounding visceral layer of the lateral plate mesoderm. This results in the anatomical and physiological specialization of the adult gut.

Animals↗
PubMed1995

Inhibition of cell fate in Drosophila by Enhancer of split genes.

The neurogenic genes of Drosophila act during many different times and places during development. It is thought their role is to repress cell fate within a group of equivalent cells and thus allow the singling out of discrete numbers of precursors. Amongst the genes at the neurogenic locus, Enhancer of split is a family of seven related genes that encode proteins containing the basic helix-loop-helix motif characteristic of transcriptional regulators. Previous functional analyses of these genes have relied on deletions which eliminate many other genes. We have ectopically expressed two of the Enhancer of split basic helix-loop-helix genes, m5 and m8, to test their effect on the determination of the precursor cells of adult sensory organs. Ectopic expression of m5 or m8 before bristle precursor division results in loss of sensory bristles from all parts of the adult fly. Ectopic expression after bristle precursor division produces bristles with aberrant cuticular structures. We have also tested the effect of reducing Enhancer of split gene function using mitotic recombination and show that this de-represses the neural fate and produces supernumerary sensory bristle neurons. We conclude that the Enhancer of split basic helix-loop-helix genes inhibit neural fate during the selection of neural precursors, and that they also play a role in restricting the neuronal fate to one of the four progeny cells of the bristle precursor.

Animals↗
PubMed1993

The role of the enhancer of split complex during cell fate determination in Drosophila.

Molecular and genetic data predict that the Enhancer of split locus functions at the end of a pathway dictating appropriate cell fate determination in a number of developmental contexts. We have sought to dissect the role individual member genes of the complex play through a molecular analysis. Of the two principle class of genes, the first, members of the basic helix-loop-helix (bHLH) class of proteins are expressed in specific regions of the embryo in subtle, overlapping patterns in cells that will differentiate as epidermis. The second, groucho, a member of the WD40 class of proteins, is expressed more generally. Immunoprecipitation experiments do not implicate groucho in G protein mediated signal transduction, a known function of many WD40 type proteins. Instead, the nuclear localisation of the protein suggests a relationship to the bHLH members of the complex. Differences in expression of the bHLH genes between neurogenic mutants implies two pathways to their activation during epidermal determination.

Amino Acid Sequence↗
PubMed1991

Cloning the mouse homolog of the human cystic fibrosis transmembrane conductance regulator gene.

The cystic fibrosis transmembrane conductance regulator is encoded by the gene known to be mutated in patients with cystic fibrosis. This paper reports the cloning and sequencing of cDNAs for the murine homolog of the human cystic fibrosis transmembrane conductance regulator gene. A clone that, by analogy to the human sequence, extends 3' from exon 9 to the poly(A) tail was isolated from a mouse lung cDNA library. cDNA clones containing exons 4 and 6b were also isolated and sequenced, but the remainder of the mRNA proved difficult to obtain by conventional cDNA library screening. Sequences spanning exons 1-9 were cloned by PCR from mouse RNA. The deduced mouse protein sequence is 78% identical to the human cystic fibrosis transmembrane regulator, with higher conservation in the transmembrane and nucleotide-binding domains. Amino acid sequences in which known cystic fibrosis missense mutations occur are conserved between man and mouse; in particular, the predicted mouse protein has a phenylalanine residue corresponding to that deleted in the most common human cystic fibrosis mutation (delta F508), which should allow the use of transgenic strategies to introduce this mutation in attempts to create a "cystic fibrosis mouse".

Amino Acid Sequence↗
PubMed1990

A new polymorphic locus, D7S411, isolated by cloning from preparative pulse-field gels is close to the mutation causing cystic fibrosis.

The mutation causing cystic fibrosis (CF) has been localized to the DNA sequence of 700 kb bounded by the loci identified by the markers pMP6d-9 (D7S399) and pJ3.11 (D7S8). A 560-kb fragment obtained after SacII digestion of DNA from a cell line containing this region of human chromosome 7 in a mouse background was separated using pulse-field gel electrophoresis and isolated from the gel. The DNA was digested with BamHI prior to cloning into lambda EMBL3. Approximately 0.1% of the resulting clones contained human repetitive sequences, and 24 such recombinants were studied. Of these, 23 are on chromosome 7; 8 clones were duplicated, and of the 15 different recombinants, 7 are between MET and INT1L1, and a further 7 are between INT1L1 and pMP6d-9, leaving a single marker, pG2, which is between pMP6d-9 and pJ3.11. pG2 recognizes an RFLP with XbaI. A cosmid walk from pG2 has generated a further marker, H80, which recognizes an RFLP with PstI. This new locus (D7S411) divides the remaining region between the CF flanking markers, thereby making it more accessible to fine pulse-field mapping and allowing the precise localization of further clones to this region. Although it is not possible to position the CF locus unequivocally with respect to D7S411, both polymorphic markers at this locus exhibit low but significant linkage disequilibrium with CF, placing the emphasis for the search for the gene on the D7S399 to D7S411 interval of 250 kb.

Blotting, Southern↗
PubMed1988

A study of the structure of the gene for lecithin: cholesterol acyltransferase in four unrelated individuals with familial lecithin: cholesterol acyltransferase deficiency.

1. We have used polyclonal antibodies and a complementary DNA clone for human lecithin:cholesterol acyltransferase (LCAT) to study LCAT protein and the structure of the LCAT gene, respectively, in patients with familial LCAT deficiency from Norway, Ireland, Germany and Italy. 2. The patients had low levels of non-functional LCAT protein in their serum as measured by rocket immunoelectrophoresis; its mol. wt. of approximately 68,000 was identical with that of LCAT in normal plasma, as judged by immunoblotting. 3. Enzymatic digestion of DNA samples from the patients produced LCAT gene fragments which were indistinguishable from those found in normal individuals. 4. We conclude that LCAT deficiency in these patients is not caused by a large deletion or rearrangement of the LCAT gene sequences.

Genes↗
PubMed1987

The isolation and characterisation of cDNA and genomic clones for human lecithin: cholesterol acyltransferase.

The protein sequencing of tryptic peptides from purified human lecithin: cholesterol acyltransferase (LCAT) identified sufficient amino-acid sequence to construct a corresponding mixed oligonucleotide probe. This was used to screen an adult human cDNA liver library, from which incomplete cDNA clones were isolated. The DNA sequence of these clones allows the prediction of the entire amino-acid sequence of the mature LCAT enzyme. The mature protein consists of 416 amino acids and contains several marked stretches of hydrophobic residues and four potential glycosylation sites. The cDNA probe detects LCAT mRNA sequences approx. 1500 bases long in human liver, but not intestine, RNA. The cDNA probe was used to isolate LCAT genomic recombinants from a human genomic library. Southern blotting data, and restriction site mapping, suggest that there is a single human LCAT structural gene between 4.3 and 5.5 kb in size.

Amino Acid Sequence↗
PubMed1987

The structural gene for lecithin:cholesterol acyl transferase (LCAT) maps to 16q22.

We have used a cDNA clone for human lecithin:cholesterol acyl transferase (LCAT) and Southern blotting techniques to identify the human LCAT gene in DNA from a series of rodent X human somatic cell hybrids. Our results are compatible with the location of the gene on human chromosome 16, and this has been confirmed using in situ hybridization of the LCAT cDNA to human metaphase chromosomes. These results confirm the earlier studies on LCAT-deficient patients, indicating that the structural gene for LCAT is on human chromosome 16q22.

Animals↗
PubMed1985

The isolation, characterisation, and chromosomal assignment of the gene for human 3-hydroxy-3-methylglutaryl coenzyme A reductase, (HMG-CoA reductase).

We have used a cDNA clone for Chinese hamster 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase to isolate a genomic recombinant for human HMG-CoA reductase. The identity of the gene was confirmed by partial sequence analysis. Several unique fragments that will be useful for restriction fragment length polymorphism (RFLP) studies were identified. In situ hybridisation of a 2.6 kb unique fragment of the gene to human metaphase chromosomes localised the human HMGCoA reductase gene to human chromosome 5q12.

Animals↗
PubMed1985

Isolation and characterisation of a cDNA clone for human apolipoprotein CI and assignment of the gene to chromosome 19.

We have synthesised a mixed oligonucleotide 17 bases long and used it to isolate cDNA clones for apolipoprotein CI (apo CI) from an adult liver cDNA library. The partial sequence of one of these clones confirms its identity. We have used this probe and Southern blotting techniques to identify the human apo CI gene in DNA from a series of rodent X human somatic cell hybrids. Our results provide evidence for the assignment of this gene to human chromosome 19.

Animals↗
PubMedDate not supplied

[Large-cell mediastinal lymphoma].

The authors report a case of large-cell mediastinal lymphoma, a recently defined, fairly infrequent, highly aggressive tumor which responds scarcely to conventional chemotherapy. On the basis of its histopathology, the tumor must be classified as a highly malignant non-Hodgkin lymphoma. The latest data in the literature give cause for a little more optimism thanks to the introduction of the most recent schemes of chemotherapy combined with large-dose radiation for consolidation. Our patient was treated with chemotherapy CHOP high-dose radiation which resulted in complete disappearance of the mediastinal mass and rapid remission of the severe symptoms of mediastinal compression. After about 30 months, instrumental and laboratory findings confirm the persistence of the complete remission.

Adult↗