Targeting Oncogenes into a Defined Subset of Mammary Cells Demonstrates That the Initiating Oncogenic Mutation Defines the Resulting Tumor Phenotype

Breast cancers exhibit high intertumoral heterogeneity in genetic alterations as well as histopathological and other phenotypic characteristics. The contribution of the initiating oncogenic mutation to tumor phenotype remains controversial, largely due to the technical difficulties in delivering genetic alterations into well-defined subsets of mammary epithelial cells. To examine how different initiating oncogenes drive tumor phenotype, we somatically delivered two oncogenes (ErbB2, PyMT) into a narrow and distinct subset of the mouse mammary epithelium defined by the expression of the progenitor marker keratin 6a (Krt6a), and compared the phenotypes of the resulting mammary tumors. While PyMT-induced tumors were well-differentiated and displayed glandular and papillary features, ErbB2-induced tumors were poorly differentiated and exhibited epithelial-to-mesenchymal transition as well as β-catenin activation. These in vivo data demonstrate that the initiating oncogene plays a key role in driving mammary tumor phenotype.     

Macrolepidoptera diversity in the Indo-Australian tropics: geographic, biotopic and taxonomic variations

Data are presented on the richness of Macrolepidoptera faunas in the Indo-Australian tropics, and on the proportional representation of the various families. Both overall diversity and diversity of families decline with latitude and also with isolation from major land areas. Exceptions are noted.
Measures of alpha-diversity from quantitative light-trap samples indicate that diversity within the tropics is often greatest at altitudes around 1000 m, declining above that level. Diversity is much lower in Pacific archipelagos. Loss of diversity through disturbance and conversion to agriculture is evident and marked. Problems in the measurement of diversity with light-traps are discussed, exemplified by results obtained using different trap types.
Changes in family proportions with habitat type are examined. Family diversity generally decreased with altitude and with disturbance and conversion to agriculture, though there are exceptions to this decline.     

Comparison of miRNA profiling during airway epithelial repair in undifferentiated and differentiated cells in vitro

Respiratory epithelium is a highly integrated structure that efficiently protects lungs from extrinsic irritants thanks to rapid repair of the wound. The repair is a complex process that requires coordinated expression of networks of genes. Plausible regulators of this process are microRNAs. We investigated whether global miRNA silencing influences the epithelial repair, and whether changes in miRNA expression profile during repair are similar between two bronchial epithelial cell cultures: differentiated and undifferentiated cells. Two bronchial cell types were used:16HBE14o- and NHBE. Transfection was performed with siRNAs against Drosha and Dicer. For miRNA profiling, non-transfected cells were cultured until confluent and harvested for RNA isolation at baseline (cells before wounding) and at different time post-wounding (8, 16, 24, and 48 h). MicroRNA expression profiling was performed using TaqMan Array Human MicroRNA Card A. Target prediction was done in miRNA body map, and pathway analysis using DAVID. Cells with downregulated Drosha and Dicer demonstrated a significantly delayed wound repair in comparison to control in both cell lines. MiRNA expression profiling revealed that ten miRNAs exhibited significant changes over time after cell injury. These genes showed a similar expression pattern in both cell lines. The predicted targets of these miRNAs were then clustered by pathway analysis into six biological groups related to wound repair. Silencing of global miRNA expression confirmed that miRNAs are crucial for airway epithelial repair. Moreover, epithelial cells of two different origins demonstrated some similarities in miRNA expression pattern during wound repair, independent of differentiation state.     

Ethnobotany of the Fort Yukon Region,Alaska

Native plants of the Fort Yukon region, Alaska, were identified as to their medicinal, edible and material uses by the Gwich'in Athabaskan and Caucasian residents. Forty eight species or groups of native plants were identified as having some use predominantly as medicines (40%) and as food or beverage (56%). Their value in past and present Gwich ’in culture is discussed.     

Extreme gender-based post-fledging brood division in the toc-toc

The possibility that parents of one sex may preferentially investin offspring of a certain sex raises profound evolutionary questionsabout the relative worth of sons and daughters to their mothersand fathers. Post-fledging brood division—in which eachparent feeds a different subset of offspring—has beenwell documented in birds. However, a lack of empirical evidencethat this may be based on offspring sex, combined with the theoreticaldifficulty of explaining such an interaction, has led researchersto consider a gender bias in post-fledging brood division highlyunlikely. Here we show that in the toc-toc, Foudia sechellarum,post-fledging brood division is extreme and determined by sex;where brood composition allows, male parents exclusively provisionmale fledglings, whereas female parents provision female fledglings.This is the first study to provide unambiguous evidence, basedon molecular sexing, that sex-biased post-fledging brood divisioncan occur in birds. Male and female parents provisioned at thesame rate and neither offspring nor parent survival appearedto be affected by the sex of the parent or offspring, respectively.The current hypotheses predicting advantages for brood divisionand preferential care for one specific type of offspring arediscussed in the light of our results.     

Influence of growth medium on surface and wall lipid of fungal spores

Conidiospores of Alternaria tenuis, Botrytis fabae, Neurospora crassa and sporangiospores of Rhizopus stolonifer from cultures on various media were shown by microelectrophoresis to have lipid on their surface. Analyses of lipid fractions obtained by sequential solvent extraction demonstrated that surface lipid forms a small but discrete layer different in composition from that within the wall. Free fatty acids, alkanes, triglycerides and other acyl lipids were identified by GC-MS. Phospholipids and sterols were absent. The qualitative and quantitative composition of both the surface and wall lipid fractions was dependent upon the growth medium used.