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Biomedical subjects

T M Slater

Publications and source records attributed to T M Slater.

6 recordsLinked to original sources

Gene discovery and gene function assignment in filamentous fungi.

Filamentous fungi are a large group of diverse and economically important microorganisms. Large-scale gene disruption strategies developed in budding yeast are not applicable to these organisms because of their larger genomes and lower rate of targeted integration (TI) during transformation. We developed transposon-arrayed gene knockouts (TAGKO) to discover genes and simultaneously create gene disruption cassettes for subsequent transformation and mutant analysis. Transposons carrying a bacterial and fungal drug resistance marker are used to mutagenize individual cosmids or entire libraries in vitro. Cosmids are annotated by DNA sequence analysis at the transposon insertion sites, and cosmid inserts are liberated to direct insertional mutagenesis events in the genome. Based on saturation analysis of a cosmid insert and insertions in a fungal cosmid library, we show that TAGKO can be used to rapidly identify and mutate genes. We further show that insertions can create alterations in gene expression, and we have used this approach to investigate an amino acid oxidation pathway in two important fungal phytopathogens.

Alleles↗

Family size, infections, and asthma prevalence in New Zealand children.

We conducted a prevalence case-control study to investigate the relation between family composition, infection, and development of asthma at age 7-9 years. Potential cases (399) and controls (398) were selected from the Wellington, NZ, arm of the International Study of Asthma and Allergies in Childhood, a population-based prevalence study. Further screening questions restricted cases to children with a diagnosis of asthma and current medication use (N = 233) and restricted controls to children without a history of wheezing and no diagnosis of asthma (N = 241). After controlling for confounders (including infections, atopy, and socioeconomic status), family size was strongly related to asthma. Having no siblings [prevalence odds ratio (POR) = 2.51; 95% confidence interval (CI) = 1.05-6.01] or one sibling (POR = 1.86; 95% CI = 1.14-3.03) was associated with an increased risk of asthma compared with having more than one sibling. Parent-reported rubeola infection (and possibly other similar viral exanthems) was independently associated with a decreased risk of asthma (POR = 0.48; 95% CI = 0.27-0.83), but reported pertussis infection (POR = 1.57; 95% CI = 0.58-4.24) and day care attendance in the first year of life (POR = 1.81; 95% CI = 0.93-3.51) were not strongly associated with increased risks of asthma.

Asthma↗

The 25 kDa synaptosomal-associated protein SNAP-25 is the major methionine-rich polypeptide in rapid axonal transport and a major substrate for palmitoylation in adult CNS.

A conspicuous correlate of the developmental transformation of axonal growth cones to synaptic terminals is a marked increase in synthesis and axonal transport of a methionine-rich, acidic polypeptide of approximately 25 kDa. This polypeptide, designated "super protein" (SuP), is the most prominent species among methionine-labeled proteins conveyed by rapid axonal transport in mature CNS and PNS neurons of warm- and cold-blooded vertebrates. We show here that SuP is identical to SNAP-25, a highly conserved synaptic protein of known primary structure, by immunoprecipitation with anti-SNAP-25 antiserum of SuP labeled with 35S-methionine and transported by retinal ganglion cells of rat and cat. In addition, we show that SNAP-25/SuP is the most prominent species among retinal polypeptides that incorporate 3H-palmitate in vivo, that it is fatty acylated through a hydroxylamine-labile, thioester bond, and that palmitoylated SNAP-25/SuP is axonally transported. Thus, SNAP-25/SuP is a rapidly transported constituent of the presynaptic apparatus and a major neuronal substrate for long-chain fatty acylation.

Animals↗

Recent appearance and molecular characterization of mitochondrial DNA deletions within a defined nematode pedigree.

The mitochondrial genome of Romanomermis culicivorax, a parasitic nematode of mosquitoes, contains an amplified 3.0-kilobase (kb) locus organized as direct repeats and as noncontiguous, inverted copies. These amplified sequences are actively undergoing rearrangement. One recent event has resulted in a 1133-base pair (bp) deletion located entirely within a single amplified segment. The deletion junction occurs between two imperfect 58-bp repeats, implicating strand pairing in this alteration. A second event has generated mitochondrial DNA (mtDNA) forms differing by a single, intact 3.0-kb repeating unit. By analyzing molecules derived from independently reared subcultures, it appears these new mtDNA forms arose within the last 170 nematode generations. Our results indicate that the occurrence and selection of novel animal mitochondrial genomes can now be studied in this experimentally manipulable nematode system.

Animals↗