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Biomedical subjects

B D Hall

Publications and source records attributed to B D Hall.

At least 109 records · Page 6Linked to original sources
PubMed1984

A new X-linked multiple congenital anomalies/mental retardation syndrome.

We report on 2 boys, the sons of sisters, and their mother's brother who have a new, X-linked multiple congenital anomalies/mental retardation (MCA/MR) syndrome. The propositus was a 16-month-old caucasian male with 1) mental retardation, 2) congenital microcephaly, 3) postnatal growth deficiency, 4) ridged metopic suture with narrow bifrontal diameter, 5) upslanted palpebral fissures with persistent epicanthal folds, strabismus, and lacrimal duct obstruction, 6) narrow palate, 7) macrodontia, 8) anteverted ears, 9) atrial septal defect, 10) dry brittle scalp hair and 11) cutis marmorata. His chromosomes were normal. His cousin and uncle were similarly affected. This distinctive MCA/MR syndrome is added to the list of X-linked malformation syndromes known at the present time.

Abnormalities, Multiple↗
PubMed1984

The Potter sequence: a clinical analysis of 80 cases.

Eighty cases of Potter sequence due to a renal or urologic abnormality were studied retrospectively. The abnormal renal findings were bilateral renal agenesis in 21.25%; cystic dysplasia in 47.5%; obstructive uropathy in 25%; and others in 5.25%. Fifteen patients had multiple congenital anomalies; of these three had aneuploidy, four had autosomal recessive syndromes, and eight were of unknown cause. Results of chromosome analysis in 41 patients and 21 sets of parents were abnormal in three patients, one of whom had a balanced translocation carrier parent; two additional patients and three parents had apparently balanced translocations. There was one recurrence within the study (the first child had bilateral renal agenesis and the second cystic dysplasia). The ultrasound prenatal diagnosis of the renal abnormality was made in eight cases between 18 and 34 weeks. Family histories were suggestive of an autosomal dominant gene disorder with incomplete penetrance in four of 45 families with nonsyndromic bilateral renal agenesis and cystic dysplasia. The evaluation of patients with the Potter sequence should include an examination for nonrenal defects, autopsy, chromosome analysis, and renal ultrasound or urologic evaluation of parents. Ultrasonographic prenatal monitoring of subsequent pregnancies in such families is strongly warranted because of a definite but unknown degree of recurrence risk.

Abnormalities, Multiple↗
PubMed1983

The primary structure of the alcohol dehydrogenase gene from the fission yeast Schizosaccharomyces pombe.

We have cloned and sequenced the alcohol dehydrogenase gene of the fission yeast Schizosaccharomyces pombe. The gene was isolated by transformation and complementation of a Saccharomyces cerevisiae strain which lacked functional alcohol dehydrogenase with an S. pombe gene bank constructed in the autonomously replicating yeast plasmid YEp13. Southern hybridization analysis indicates that S. pombe contains only one alcohol dehydrogenase gene. The structural region of the gene is 50% homologous to the alcohol dehydrogenase encoding genes of the budding yeast S. cerevisiae. The gene exhibits a very strong codon usage bias; with the set of predominantly used codons generally resembling that which S. cerevisiae employs preferentially. All of the differences in codon usage bias between S. pombe and S. cerevisiae are in the direction of greater G + C content in S. pombe codons. It is argued that this observation supports the hypothesis that selection toward uniform codon-anticodon binding energies contributes to codon usage bias and that the optimum binding energy is, on the average, higher in S. pombe than S. cerevisiae.

Alcohol Dehydrogenase↗
PubMed1983

Brief clinical report: a new syndrome of hemangiomatous branchial clefts, lip pseudoclefts, and unusual facial appearance.

Two unrelated children (one male, the other female) had unusual craniofacial anomalies consisting of hemangiomatous branchial clefts, lip pseudoclefts, and identical unusual facial appearance. One also had unilateral microphthalmia and both had congenital nasolacrimal duct obstruction. Two similar, sporadic cases from the literature were also identified. These four cases form the basis of a new, distinctly recognizable pattern of malformation.

Branchioma↗
PubMed1983

The promoter sequence of a yeast tRNAtyr gene.

Thirty-one base substitution mutations within the yeast SUP4 tRNAtyr gene were used to probe the effects of different intragenic sequences on promoter activity. The various mutant plasmids were tested quantitatively for their in vitro template activity and for their ability to block competitively the transcription of a reference gene. Five mutations within the coding sequence of SUP4 decreased template activity for pre-tRNAtyr synthesis. The competition assays revealed 11 mutant genes that behaved differently than SUP4-o. Six were weaker competitors and five were stronger. The 12 mutations affecting template activity or competition are clustered in three regions: those encoding the dihydrouracil (D) arm, the extra loop, and the T psi arm of the tRNA. All of the mutations that reduce competition involve base changes that decrease homology to a eucaryotic tRNA consensus sequence in the highly conserved D and T psi regions. Three of the five up mutations increased homology to the tRNA consensus sequence.

Base Sequence↗
PubMed1982

An in vitro RNA polymerase III system from S. cerevisiae: effects of deletions and point mutations upon SUP4 gene transcription.

A soluble cell-free extract containing RNA polymerase III and factors essential for selective transcription of the yeast SUP4-o tRNATyr gene was prepared from Saccharomyces cerevisiae cells. An intragenic promoter for yeast RNA polymerase III was identified within the yeast tRNATyr coding sequence by testing several sup4 genes with 5'- and 3'-terminal deletions in the homologous transcription system. Thirty-four different sup4 genes with spontaneous mutations were also tested in the in vitro system. Two point mutations drastically reduced transcription initiation and two other mutations caused premature termination. These mutations have nearly identical effects on SUP4 gene transcription by Xenopus RNA polymerase III (1), which demonstrates that the essential features of RNA polymerase III transcription initiation and termination signals have been conserved throughout the course of eukaryotic evolution.

Base Sequence↗
PubMed1982

Synthesis and assembly of hepatitis B virus surface antigen particles in yeast.

The surface antigens of hepatitis B virus (HBsAg) has been synthesized in the yeast Saccharomyces cerevisiae by using an expression vector that employs the 5'-flanking region of yeast alcohol dehydrogenase I as a promotor to transcribe surface antigen coding sequences. The protein synthesized in yeast is assembled into particles having properties similar to the 22-nm particles secreted by human cells.

Alcohol Dehydrogenase↗
PubMed1982

The primary structure of the Saccharomyces cerevisiae gene for alcohol dehydrogenase.

The DNA sequence of the gene for the fermentative yeast alcohol dehydrogenase has been determined. The structural gene contains no introns. The amino acid sequence of the protein as determined from the nucleotide sequence disagrees with the published alcohol dehydrogenase isozyme I (ADH-I) sequence for 5 of the 347 amino acid residues. At least one, and perhaps as many as four, of these differences is probably due to ADH-I protein heterogeneity in different yeast strains and not to sequencing errors. S1 nuclease was used to map the 5' and 3' ends of the ADH-I mRNA. There are two discrete, mature 5' ends of the mRNA, mapping 27 and 37 nucleotides upstream of the translation initiating ATG. These two equally prevalent termini are 101 and 91 nucleotides, respectively, downstream from a TATAAA sequence. Analysis of the 3' end of ADH-I mRNA disclosed two minor ends upstream of the major poly(A) addition site. These three ends map 24, 67, and 83 nucleotides, respectively, downstream from the translation-terminating TAA triplet. The sequence AA-TAAG is found 28 to 34 nucleotides upstream of each ADH-I mRNA poly(A) addition site. Sequence comparisons of these three 3' ends with those for four other yeast mRNAs yielded a 13-nucleotide consensus sequence to which TAAATAAGA is central. All of the known yeast poly(A) addition sites map at or near the A residue of a CTA site 25 to 40 nucleotides downstream from this consensus octamer.

Alcohol Dehydrogenase↗
PubMed1982

Codon selection in yeast.

Extreme codon bias is seen for the Saccharomyces cerevisiae genes for the fermentative alcohol dehydrogenase isozyme I (ADH-I) and glyceraldehyde-3-phosphate dehydrogenase. Over 98% of the 1004 amino acid residues analyzed by DNA sequencing are coded for by a select 25 of the 61 possible coding triplets. These preferred codons tend to be highly homologous to the anticodons of the major yeast isoacceptor tRNA species. Codons which necessitate site by side GC base pairs between the codons and the tRNA anticodons are always avoided whenever possible. Codons containing 100% G, C, A, U, GC, or AU are also avoided. This provides for approximately equivalent codon-anticodon binding energies for all preferred triplets. All sequenced yeast genes show a distinct preference for these same 25 codons. The degree of preference varies from greater than 90% for glyceraldehyde-3-phosphate dehydrogenase and ADH-I to less than 20% for iso-2 cytochrome c. The degree of bias for these 25 preferred triplets in each gene is correlated with the level of its mRNA in the cytoplasm. Genes which are strongly expressed are more biased than genes with a lower level of expression. A similar phenomenon is observed in the codon preferences of highly expressed genes in Escherichia coli. High levels of gene expression are well correlated with high levels of codon bias toward 22 of the 61 coding triplets. As in yeast, these preferred codons are highly complementary to the major cellular isoacceptor tRNA species. In at least four cases (Ala, Arg, Leu, and Val), these preferred E. coli codons are incompatible with the preferred yeast codons.

Alcohol Oxidoreductases↗
PubMed1982

Genetic analysis of the processing of a spliced tRNA.

We analyzed the effect of 18 single nucleotide changes on the processing of the transcripts produced by cloned yeast tRNATyr genes after microinjection into the nucleus of living Xenopus oocytes. The processing step most easily blocked by mutation is the early maturation of the 5' and 3' termini of the tRNATyr primary transcript, involving removal of 5'-leader and 3'-trailer sequences and CCA addition. The enzymes seem to recognize the whole tRNA cloverleaf structure since mutations in all regions of the molecule can stop processing. Mutations that affect splicing of the 92-nucleotide precursor (which has mature ends but still contains the intervening sequence, and is the normal substrate for the splicing enzymes), are located in the vicinity of the intervening sequence. Base modification enzymes that add pseudouridine, 1-methyladenosine and 5-methylcytosine appear rather insensitive to changes in secondary and tertiary structure of early transcripts in the 16 mutants examined. These enzymes may recognize only limited regions of the precursor RNA. RNA polymerase III behaves as if able to count the number of Us added before termination; and aberrant termination products in two mutants suggest that the secondary structure of the nascent transcript can be very imortant in eukaryotic transcription termination.

Animals↗
PubMed1982

Mutations at the Saccharomyces cerevisiae SUP4 tRNA(Tyr) locus: isolation, genetic fine-structure mapping, and correlation with physical structure.

The SUP4 tRNA(Tyr) locus in Saccharomyces cerevisiae has been studied by the isolation and characterization of mutations at the SUP4 gene which result in the loss of suppressor function. Most of the mutations act as single-site mutations, whereas about a third of the mutations are deletions of the entire gene. Two meiotic fine-structure maps of the gene were made. The first mapping technique placed 10 mutations plus the sup4+ anticodon on a map by a measurement of levels of recombination between pairs of mutations. The second map utilized a more qualitative estimate of recombination frequency, allowing 69 mutations and the sup4+ anticodon to be mapped. The maps were compared with the physical structure of the gene for the 34 mutations whose nucleotide alteration has been determined by DNA sequencing (Koski et al., Cell 22:415-425, 1980; Kurjan et al., Cell 20:701-709, 1980). Both maps show a good correlation with the physical structure of the gene, even though certain properties of genetic fine-structure maps, such as marker effects and "map expansion," were seen.

Chromosome Mapping↗
PubMed1982

Structure of the Schizosaccharomyces pombe cytochrome c gene.

The cytochrome c gene of the fission yeast Schizosaccharomyces pombe has been cloned by using the Saccharomyces cerevisiae iso-1-cytochrome c gene as a molecular hybridization probe. The DNA sequence and the 5' termini of the mRNA transcripts of the gene have been determined. The DNA sequence has confirmed, with two exceptions, the previously determined protein sequence. The nonrandom distribution of silent third base differences which was observed between the two cytochrome c genes of S. cerevisiae does not extend to the S. pombe cytochrome c gene, suggesting that there are no constraints other than protein function and codon usage which have acted to conserve the cytochrome DNA sequences of the two yeasts. Introduction of the S. pombe cytochrome c gene on a yeast plasmid into a S. cerevisiae mutant which lacked functional cytochrome c transformed that recipient strain for the ability to grow on a nonfermentable carbon source. This implies that the S. pombe cytochrome c gene has all the regulatory signals which are required for its expression in S. cerevisiae, and that none of the amino acid differences between the cytochrome c proteins of the two yeasts has a drastic effect on the function of the protein in vivo.

Ascomycota↗
PubMed1981

Expression of a human gene for interferon in yeast.

A DNA sequence coding for mature human leukocyte interferon D (LeIF-D) was linked with DNA fragments of the 5'-flanking sequences of the Saccharomyces cerevisiae (yeast) alcohol dehydrogenase I gene in a plasmid capable of autonomous replication and selection in both yeast and Escherichia coli. Yeast cells transformed by these plasmids synthesize up to 1 x 10(6) molecules of biologically active LeIF-D per cell.

Alcohol Oxidoreductases↗