Development of fly tolerance to consuming a high-protein diet requires physiological, metabolic and transcriptional changes.

Mortality in insects consuming high-protein-and-low-carbohydrate diets resembles a type III lifespan curve with increased mortality at an early age and few survivors that live a relatively long lifespan. We selected for a Drosophila line able to live for a long time on an imbalanced high-protein-low-carbohydrate diet by carrying out five rounds of breeding to select for the most long-lived survivors. Adaptation to this diet in the selected line was studied at the biochemical, physiological and transcriptomic levels. The selected line of flies consumed less of the imbalanced food but also accumulated more storage metabolites: glycogen, triacylglycerides, and trehalose. Selected flies also had a higher activity of alanine transaminase and a higher urea content. Adaptation of the selected line on the transcriptomic level was characterized by down-regulation of genes encoding serine endopeptidases (Jon25i, Jon25ii, betaTry, and others) but up-regulation of genes encoding proteins related to the immune system, such as antimicrobial peptides, Turandot-family humoral factors, hexamerin isoforms, and vitellogenin. These sets of down- and up-regulated genes were similar to those observed in fruit flies with suppressed juvenile hormone signaling. Our data show that the physiological adaptation of fruit flies to a high-protein-low-carbohydrate diet occurs via intuitive pathways, namely a decrease in food consumption, conversion of amino acids into ketoacids to compensate for the lack of carbohydrate, and accumulation of storage metabolites to eliminate the negative effects of excess amino acids. Nevertheless, transcriptomic adaptation occurs in a counter-intuitive way likely via an influence of gut microbiota on food digestion.

Leptomycin B induces apoptosis in cells containing the whole HPV 16 genome.

Cervical cancer is a major cause of death in women worldwide and is strongly associated with human papillomavirus (HPV) infection. Integration of HPV is thought to be a key step in malignant progression, and is associated with loss of regulation of the viral E6 and E7 oncogenes. Leptomycin B (LMB), a nuclear export inhibitor, has previously been shown to induce apoptosis in primary keratinocytes transduced with the HPV 16 E7 or E6/E7 genes, but not in normal cells. We show here that LMB can also induce apoptosis in derivatives of the W12 cell line that contain either episomal or integrated HPV 16. Cells transduced with HPV 16 E7 or E6/E7, and the episomal and integrated W12 derivatives showed distinct temporal expression patterns of the apoptotic markers activated caspase-3 and M30. The expression of both markers occurred later in the episomal derivatives than in either transduced cells or W12 derivatives containing integrated HPV. These findings suggest that, although LMB can induce apoptosis in keratinocytes containing episomal or integrated HPV 16, genome status is likely to influence the response of HPV-associated anogenital lesions to LMB treatment.

Fruit flies may face a nutrient-dependent life-history trade-off between secondary sexual trait quality, survival and developmental rate.

Optimal life-history strategies are those that best allocate finite environmental resources to competing traits. We used the geometric framework for nutrition to evaluate life-history strategies followed by Drosophila melanogaster by measuring the condition-dependent performance of life-history traits, including the morphology of male secondary sexual characters, sex combs. We found that depending on their rearing environment flies faced different forms of trait trade-offs and accordingly followed different life-history strategies. High-energy, high-carbohydrate, low-protein diets supported development of the largest and most symmetrical sex combs, however, consistent with handicap models of sexual selection these foods were associated with reduced fly survival and developmental rate. Expressing the highest quality sex combs may have required secondary sexual trait quality to be traded-off with developmental rate, and our results indicated that flies unable to slow development died. As larval nutritional environments are predominantly determined by female oviposition substrate choice, we tested where mated female flies laid the most eggs. Mothers chose high-energy, high-protein foods associated with rapid larval development. Mothers avoided high-carbohydrate foods associated with maximal sex comb expression, showing they may avoid producing fewer 'sexy' sons in favour of producing offspring that develop rapidly.

Intergenerational effects of nutrition on immunity: a systematic review and meta-analysis.

Diet and immunity are both highly complex processes through which organisms interact with their environment and adapt to variable conditions. Parents that are able to transmit information to their offspring about prevailing environmental conditions have a selective advantage by 'priming' the physiology of their offspring. We used a meta-analytic approach to test the effect of parental diet on offspring immune responses. Using the geometric framework for nutrition (a method for analysing diet compositions wherein food nutrient components are expressed as axes in a Cartesian coordinate space) to define dietary manipulations in terms of their energy and macronutrient compositions, we compiled the results of 226 experiments from 38 published papers on the intergenerational effects of diet on immunity, across a range of study species and immunological responses. We observed intergenerational impacts of parental nutrition on a number of offspring immunological processes, including expression of pro-inflammatory biomarkers as well as decreases in anti-inflammatory markers in response to certain parental diets. For example, across our data set as a whole (encompassing several types of dietary manipulation), dietary stress in parents was seen to significantly increase pro-inflammatory cytokine levels measured in offspring (overall d = 0.575). All studies included in our analysis were from experiments in which the offspring were raised on a normal or control diet, so our findings suggest that a nutrition-dependent immune state can be inherited, and that this immune state is maintained in the short term, despite offspring returning to an 'optimal' diet. We demonstrate how the geometric framework for nutrition can be used to disentangle the role that different forms of dietary manipulation can have on intergenerational immunity. For example, offspring B-cell responses were significantly decreased when parents were raised on a range of different diets. Similarly, our approach allowed us to show that a parental diet elevated in protein (regardless of energy composition and relative to a control diet) can increase expression of inflammatory markers while decreasing B-cell-associated markers. By conducting a systematic review of the literature, we have identified important gaps that impair our understanding of the intergenerational effects of diet, such as a paucity of experimental studies involving increased protein and decreased energy, and a lack of studies directed at the whole-organism consequences of these processes, such as immune resilience to infection. The results of our analyses inform our understanding of the effects of diet on physiological state across diverse biological fields, including biomedical sciences, maintenance of agricultural breed stock and conservation breeding programs, among others.

Integrative taxonomy resolves the cryptic and pseudo-cryptic Radula buccinifera complex (Porellales, Jungermanniopsida), including two reinstated and five new species.

Molecular data from three chloroplast markers resolve individuals attributable to Radula buccinifera in six lineages belonging to two subgenera, indicating the species is polyphyletic as currently circumscribed. All lineages are morphologically diagnosable, but one pair exhibits such morphological overlap that they can be considered cryptic. Molecular and morphological data justify the re-instatement of a broadly circumscribed ecologically variable R. strangulata, of R. mittenii, and the description of five new species. Two species Radula mittenii Steph. and R. notabilis sp. nov. are endemic to the Wet Tropics Bioregion of north-east Queensland, suggesting high diversity and high endemism might characterise the bryoflora of this relatively isolated wet-tropical region. Radula demissa sp. nov. is endemic to southern temperate Australasia, and like R. strangulata occurs on both sides of the Tasman Sea. Radula imposita sp. nov. is a twig and leaf epiphyte found in association with waterways in New South Wales and Queensland. Another species, R. pugioniformis sp. nov., has been confused with Radula buccinifera but was not included in the molecular phylogeny. Morphological data suggest it may belong to subg. Odontoradula. Radula buccinifera is endemic to Australia including Western Australia and Tasmania, and to date is known from south of the Clarence River on the north coast of New South Wales. Nested within R. buccinifera is a morphologically distinct plant from Norfolk Island described as R. anisotoma sp. nov. Radula australiana is resolved as monophyletic, sister to a species occurring in east coast Australian rainforests, and nesting among the R. buccinifera lineages with strong support. The molecular phylogeny suggests several long-distance dispersal events may have occurred. These include two east-west dispersal events from New Zealand to Tasmania and south-east Australia in R. strangulata, one east-west dispersal event from Tasmania to Western Australia in R. buccinifera, and at least one west-east dispersal from Australia to New Zealand in R. australiana. Another west-east dispersal event from Australia to Norfolk Island may have led to the budding speciation of R. anisotoma. In contrast, Radula demissa is phylogeographically subdivided into strongly supported clades either side of the Tasman Sea, suggesting long distance dispersal is infrequent in this species.

Synergy of peptide and sugar in O-GlcNAcase substrate recognition.

Protein O-GlcNAcylation is an essential reversible posttranslational modification in higher eukaryotes. O-GlcNAc addition and removal is catalyzed by O-GlcNAc transferase and O-GlcNAcase, respectively. We report the molecular details of the interaction of a bacterial O-GlcNAcase homolog with three different synthetic glycopeptides derived from characterized O-GlcNAc sites in the human proteome. Strikingly, the peptides bind a conserved O-GlcNAcase substrate binding groove with similar orientation and conformation. In addition to extensive contacts with the sugar, O-GlcNAcase recognizes the peptide backbone through hydrophobic interactions and intramolecular hydrogen bonds, while avoiding interactions with the glycopeptide side chains. These findings elucidate the molecular basis of O-GlcNAcase substrate specificity, explaining how a single enzyme achieves cycling of the complete O-GlcNAc proteome. In addition, this work will aid development of O-GlcNAcase inhibitors that target the peptide binding site.

Behavioural phase polyphenism in the Australian plague locust (Chortoicetes terminifera).

Swarming and the expression of phase polyphenism are defining characteristics of locust species. Increases in local population density mediate morphological, physiological and behavioural changes within individuals, which correlate with mass marching of juveniles in migratory bands and flying swarms of adults. The Australian plague locust (Chortoicetes terminifera) regularly forms migratory bands and swarms, but is claimed not to express phase polyphenism and has accordingly been used to argue against a central role for phase change in locust swarming. We demonstrate that juvenile C. terminifera express extreme density-dependent behavioural phase polyphenism. Isolated-reared juveniles are sedentary and repelled by conspecifics, whereas crowd-reared individuals are highly active and are attracted to conspecifics. In contrast to other major locust species, however, behavioural phase change does not accumulate across generations, but shifts completely within an individual's lifetime in response to a change in population density.

Selective induction of apoptosis by leptomycin B in keratinocytes expressing HPV oncogenes.

Human papillomavirus (HPV) infection is strongly associated with the development of anogenital neoplasia, particularly cervical cancer. It has been estimated that 99.7% of all cervical carcinomas are attributable to infection with HPV, and types 16 and 18 account for the vast majority of such cases. Both of these 'high risk' HPV types encode the oncoproteins E6 and E7, which exert multiple effects on many proteins involved in cell-cycle regulation, including p53. The nuclear export protein inhibitor leptomycin B (LMB) has been shown to cause the nuclear sequestration of p53 in cervical carcinoma cells. We demonstrate that LMB induces apoptosis selectively at nanomolar concentrations in primary human keratinocytes (PHKs) expressing HPV oncogenes. Both monolayer and organotypic raft cultures of transduced PHKs were highly susceptible to treatment with LMB. By contrast, although LMB stimulated p53 accumulation in normal PHKs, no significant induction of apoptosis was detected on Western blots or immunostained monolayer/raft cells, or following pulsed exposure to the drug. Furthermore, topical application of microM concentrations of LMB to mouse skin was non-toxic. These data suggest that the topical application of LMB to HPV-infected intra-epithelial lesions may represent a specific and effective therapeutic strategy against HPV-associated anogenital neoplasia.