Selection component analysis of natural polymorphisms using population samples including mother-offspring combinations, III

Population samples including mother-offspring combinations with three or more offspring provide complete information on the selection components in a monogamous organism with discrete generations. The theory for the analysis of a sample consisting of adult individuals including combinations of a mother and a number of her offspring is developed for a one-locus two-allele polymorphism, and extension of the analysis to more complex polymorphisms is discussed. The analysis is illustrated by data from a population of the amphipod Gammarus oceanicus.     

Use of Menopausal Hormone Therapy and Bioidentical Hormone Therapy in Australian Women 50 to 69 Years of Age: Results from a National,Cross-Sectional Study

Menopausal Hormone Therapy (MHT) use in Australia fell by 55% from 2001 to 2005, following the release of large-scale findings on its risks and benefits. Comprehensive national data, including information on overall prevalence of MHT use as well as information on duration of use in Australia have not been reported since the 2004–5 National Health Survey, when 11% of women aged 45+ years were estimated to be current MHT users. No national data are available on prevalence of use of “bioidentical” hormone therapy (BHT). The objective of this study was to determine recent prevalence of MHT and BHT use. A cross-sectional, national, age-stratified, population survey was conducted in 2013. Eligible women, aged 50–69 years, resident in Australia were randomly sampled in 5-year age groups from the Medicare enrolment database (Australia’s universal health scheme). The response rate was 22% based on return of completed questionnaires, and analyses were restricted to 4,389 women within the specified age range. The estimated population-weighted prevalence of current use of MHT was 13% (95%CI 12–14), which was broadly similar to the previously reported national figures in 2004–5, suggesting that the use of MHT in Australia has largely stabilised over the past decade. A total of 39% and 20% of current-users with an intact uterus reported use of oestrogen-progestagen MHT and oestrogen-only MHT, respectively, whereas 77% of hysterectomised current-users used oestrogen-only MHT. Almost three-quarters of current-users [population-weighted prevalence 9% (95%CI 8–10)] had used MHT for ≥5 years. In regard to BHT, estimated population-weighted prevalence of ever use was 6% (95%CI 6–7) and 2% (95%CI 2–3) for current use. The population-weighted prevalence of MHT and BHT combined, in current users in their fifties and sixties was 15% (95%CI 14–16). These data provide a recent national “snapshot” of Australian women’s use of both conventional MHT and of BHT.     

Evolution and intraspecific exploitative competition I. One-locus theory for small additive gene effects

Using the model of exploitative competition of R. H. MacArthur and R. Levins (1967, Amer. Natur. 101, 377–385), evolution at a gene locus which influences the niche position is considered. The locus has multiple alleles, and the contributions of the alleles to the genotypic value are additive. The resource spectrum and the utilization functions of the genotypes are assumed to be Gaussian. Evolution will make the mode of the niche converge to the resource optimum, as long as the allele contributions are small compared to the distance between the mode of the niche and the resource optimum. When this distance is of the same order of magnitude as the allele contributions, then the globally stable equilibrium will maintain at most two alleles in the population, unless the allele contributions are large. Classical overdominance is not needed to maintain polymorphism. This result predicts high linkage disequilibrium in similar multilocus models. It is concluded that intraspecific competition can be a powerful force in maintaining two-allele polymorphisms, and that it can maintain high linkage disequilibrium among closely linked loci.     

Notch signaling in the pigmented epithelium of the anterior eye segment promotes ciliary body development at the expense of iris formation

The ciliary body and iris are pigmented epithelial structures in the anterior eye segment that function to maintain correct intra‐ocular pressure and regulate exposure of the internal eye structures to light, respectively. The cellular and molecular factors that mediate the development of the ciliary body and iris from the ocular pigmented epithelium remain to be fully elucidated. Here, we have investigated the role of Notch signaling during the development of the anterior pigmented epithelium by using genetic loss‐ and gain‐of‐function approaches. Loss of canonical Notch signaling results in normal iris development but absence of the ciliary body. This causes progressive hypotony and over time leads to phthisis bulbi, a condition characterized by shrinkage of the eye and loss of structure/function. Conversely, Notch gain‐of‐function results in aniridia and profound ciliary body hyperplasia, which causes ocular hypertension and glaucoma‐like disease. Collectively, these data indicate that Notch signaling promotes ciliary body development at the expense of iris formation and reveals novel animal models of human ocular pathologies.     

Global phylogeography of sailfish: deep evolutionary lineages with implications for fisheries management

Hydrobiologia - Since the Miocene profound climatic changes have influenced the biology and ecology of species worldwide, such as their connectivity, genetic population structure, and biogeography....     

Tissue-specific Salmonella Typhimurium gene expression during persistence in pigs

Salmonellosis caused by Salmonella Typhimurium is one of the most important bacterial zoonotic diseases. The bacterium persists in pigs resulting in asymptomatic 'carrier pigs', generating a major source for Salmonella contamination of pork. Until now, very little is known concerning the mechanisms used by Salmonella Typhimurium during persistence in pigs. Using in vivo expression technology (IVET), a promoter-trap method based on ΔpurA attenuation of the parent strain, we identified 37 Salmonella Typhimurium genes that were expressed 3 weeks post oral inoculation in the tonsils, ileum and ileocaecal lymph nodes of pigs. Several genes were expressed in all three analyzed organs, while other genes were only expressed in one or two organs. Subsequently, the identified IVET transformants were pooled and reintroduced in pigs to detect tissue-specific gene expression patterns. We found that efp and rpoZ were specifically expressed in the ileocaecal lymph nodes during Salmonella peristence in pigs. Furthermore, we compared the persistence ability of substitution mutants for the IVET-identified genes sifB and STM4067 to that of the wild type in a mixed infection model. The ΔSTM4067::kanR was significantly attenuated in the ileum contents, caecum and caecum contents and faeces of pigs 3 weeks post inoculation, while deletion of the SPI-2 effector gene sifB did not affect Salmonella Typhimurium persistence. Although our list of identified genes is not exhaustive, we found that efp and rpoZ were specifically expressed in the ileocaecal lymph nodes of pigs and we identified STM4067 as a factor involved in Salmonella persistence in pigs. To our knowledge, our study is the first to identify Salmonella Typhimurium genes expressed during persistence in pigs.