Early rattles, purrs and whistles as predictors of later wheeze.

BACKGROUND: Asthma is a common condition characterised by wheeze. Many different respiratory sounds are interpreted by parents as "wheeze" in young children. AIM: To relate different respiratory sounds reported as wheeze in 2-year-olds to asthma outcomes at age 5 years. METHODS: As part of a longitudinal cohort study, parents completed respiratory questionnaires for their children at 2 and 5 years of age. Parents who reported wheeze were given options to describe the sound as rattling, purring or whistling. RESULTS: Of the 1371 2-year-olds surveyed, 210 had current wheeze, of whom 124 had rattle, 49 purr and 24 whistle. Children with whistle at 2 years were more likely to have mothers with asthma, and children with rattle and purr were more likely to be exposed to tobacco smoke. Wheeze status was ascertained at age 5 years in 162 (77%) children with wheeze at 2 years of age. Whistle persisted in 47% of affected children, rattle in 20%, and purr in 13% (p = 0.023). At 5 years of age, asthma medication was prescribed in 40% with whistle, 11% with rattle, and 18% with purr at 2 years of age (p = 0.017). CONCLUSIONS: This study shows different risk factors and outcomes for different respiratory sounds in 2-year-olds: compared with other respiratory sounds, whistle is likely to persist and require asthma treatment in future.

Microsatellite evolution in congeneric mammals: domestic and bighorn sheep.

We compared genotypes at eight (AC)n microsatellite loci in domestic sheep (Ovis aries) and wild Rocky Mountain bighorn sheep (O. canadensis). The domestic sheep had greater genetic variation, higher allele-size variances, and larger allele sizes than the wild sheep. Accumulating evidence from higher taxonomic comparisons shows that these parameters are biased if microsatellite loci are selected in one taxon and used in another. Our results demonstrate similar biases between congeneric species. We compared standard measures of genetic variation, differentiation, and distance within and between species (H, D, FST) to newer measures based on allele-size variance (SW, SB, RST). The size-based distances better detected species-level divergence, but standard measures better distinguished allopatric populations. Empirical calibration of these measures at the subspecies level is needed to establish their useful ranges.

One of two growth hormone genes in coho salmon is sex-linked.

Salmonid fishes have two growth hormone genes resulting from their polyploid ancestry. We used the polymerase chain reaction to examine genetic variation in the third intron (C) of both of these genes in coho salmon (Oncorhynchus kisutch). A polymorphism in the length of intron C in GH-1 is due to a variable number of copies of a 31-nt repeat that is absent from GH-1 of the closely related chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Oncorhynchus mykiss). Thus, this tandem repeat sequence has become established in the genome of coho salmon since the separation of this species from its closest relatives. All male coho salmon examined have an allele at the second growth hormone gene, GH-2, that is not found in females. GH-2 is thus on the sex chromosome and there is no recombination between GH-2 and the sex-determining locus (SEX). Sequences of intron C indicate much greater divergence between the X chromosome-specific allele and the Y chromosome-specific allele within coho salmon than between the X chromosome-specific alleles of coho and the closely related chinook salmon. Thus, absence of recombination between GH-2 and SEX apparently predates separation of these two species.

MITOCHONDRIAL GENOTYPES HAVE NO DETECTABLE EFFECTS ON MERISTIC TRAITS IN CUTTHROAT TROUT HYBRID SWARMS.

Efforts to detect effects of cytoplasmic genes are confounded by the problem of partitioning nuclear and cytoplasmic effects. In this study we test for effects of mtDNA haplotype on development in hybrid populations of cutthroat trout (Oncorhynchus clarki) with randomly associated nuclear and mtDNA genotypes. We have previously described several intraspecific hybrid swarms formed by interbreeding of westslope cutthroat trout (O. c. lewisi) and Yellowstone cutthroat trout (O. c. bouvieri). Genetic distance between these subspecies is high (Nei's D = 0.30; mtDNA P = 0.02), and diagnostic alleles at multiple nuclear loci and two distinct mtDNA haplotypes are present in the hybrids. Historical associations between alleles at nuclear loci and between cytotypes and nuclear alleles have largely decayed. We test for differences in meristic characters between fish with alternate mtDNA haplotypes. Counts and fluctuating bilateral asymmetry for these characters have been previously shown to be sensitive indicators of genetic differences that affect development. No differences were found between mtDNA types in meristic counts or fluctuating asymmetry. Therefore, the alternate mtDNA haplotypes had no detectable effect on development as measured by meristic counts in these hybrid populations. However, diagnostic alleles at one nuclear allozyme locus (CK-CI) were associated with several fin ray counts.

ASSOCIATIONS BETWEEN MITOCHONDRIAL AND NUCLEAR GENOTYPES IN CUTTHROAT TROUT HYBRID SWARMS.

We examined mtDNA and nuclear allozyme genotypes in hybrid populations formed from interbreeding of westslope cutthroat trout (Oncorhynchus clarki lewisi) and Yellowstone cutthroat trout (O. c. bouvieri). These subspecies show substantial genetic divergence (Nei's D = 0.30; mtDNA P = 0.02). Diagnostic alleles at multiple nuclear loci and two distinct mtDNA haplotypes segregate in the hybrids. Nuclear and mtDNA genotypes are largely randomly associated, although there is slight disequilibrium in both nuclear and cytonuclear measures in some samples. Consistent positive gametic disequilibria for three pairs of nuclear loci confirm one previously reported linkage, and indicate two more. Allele frequencies provide no evidence for selection on individual chromosome segments. However, westslope mtDNA haplotype frequencies exceed westslope nuclear allele frequencies in all samples. This may be explained by differences in the frequency of occurrence of reciprocal F1 matings, by viability, fertility, or sex ratio differences in the progeny of reciprocal matings, or by weak selection on mtDNA haplotypes.

Alterations in human endometrial protein synthesis during the menstrual cycle and in progestone-stimulated organ culture.

The cytoplasmic protein content of endometrium from women at various times in the menstrual cycle has been examined by means of polyacrylamide gel electrophoresis using a double-label isotope technique. Analysis of the gels for altered label ratios suggests an increase in the concentration of a single protein band during the immediate postovulatory period that can be duplicated by the addition of progesterone to organ cultures of preovulatory endometrium. An alteration in the protein content is also observed in the same section of these gels when they are stained and scanned. The protein band of interest migrates on sodium dodecyl sulfate gels at a rate that establishes its approximate molecular weight as 51,500.