The evolutionary ecology of Festuca Novae-Zelandiae in Mid-Canterbury, New Zealand

Festuca novae-zelandiae (Hack.) Cockayne is a long-lived, caesptiose grass indigenous to New Zealand. It has expanded dramatically in range in 1000 years of human settlement. This study was conducted to determine how generalist life-history attributes and 'adaptive' variation have enabled this species to adjust to environmental change. A range of aspects of the biology of F. novae-zelandiae were investigated. Reproduction in 155 individuals over four seasons was monitored. Only 17.4% of individuals flowered every year and 36.1 % did not flower at all. However, the reproductive output of the population was still relatively consistent between years. Reproduction of individuals and the pre-dispersal fate of seeds was compared among eight sites. Differences existed among sites for most attributes measured. Site factors appeared to mask any effects of tussock density on culm production. Total seed predation was positively related to density and negatively to altitude. A flightless fly, Diplotoxa moorei (Diptera, Chloropidae) was found to be the most common identifiable seed predator, accounting for up to 8% of seeds produced in some populations. Seed germination was compared for eight populations in laboratory trials and most seeds germinated easily. Mean final % germination across all populations was 86%. Seedlings were monitored in the field for 30 months. They commonly established on mat-vegetation, were very slow-growing (mean of 0.6 leaves yr-1) and had a half-life of 12 months. Tillers in 26 tussocks were tagged and monitored for 30 months. Tillering was concentrated in spring, tillers lived on average 15.2 months and the majority (64%) did not produce daughter tillers. Tillering rate was not affected by either position within a tussock or size of the tussock. A stage-based approach was used to investigate population structure. Stages were defined using discriminant analysis. The discriminant function was then used to assign stages to 255 tussocks which had been measured at the beginning and end of a two year period. Transition probabilities were calculated between stages. Transitions were distinctly non-linear and tussock size and condition could vary widely in the space of two years in response to environmental fluctuations. The genetic identity of mapped tussocks was investigated using isozyme electrophoresis and it was found that clonal fragmentation did not contribute significantly to the maintenance of population densities. Patterns of variation at different taxonomic levels were compared using three taxa: F. novae-zelandiae s.s., a distinct high altitude form of F. novae-zelandiae and a closely related species, F. matthewsii. Vegetation composition was investigated using ordination and classification techniques. Environmental gradients in altitude, temperature and rainfall were important in explaining observed patterns. The vegetation composition at "high altitude" F. novae-zelandiae sites was more distinct from that of F. novae-zelandiae s.s. sites than the latter was from F. matthewsii sites. Morphological variation in the same taxa was investigated using Principal Components Analysis. The same environmental factors were important to observed patterns of variation. Populations within F. novae-zelandiae possessed some genetically-determined differentiation that related to habitat. A narrow zone of intermediacy was found between F. novae-zelandiae s.s. and F. matthewsii. Plants from populations of the three taxa were grown in cultivation. Culms of F. matthewsii emerged four weeks prior to F. novae-zelandiae s.s. "High altitude" F. novae-zelandiae was more similar to F. matthewsii in flowering phenology. Levels of biochemical variation in populations of all three taxa were investigated using isozyme electrophoresis. All populations were characterised by high within-population variation and relatively low between-population variation. The differences between the three taxa were small. Variation among populations related to environmental factors but not to the proximity of populations. The adaptiveness of populations to their own environment was tested using reciprocal transplants. No 'home-site' advantage was found. All populations proved to be highly plastic in growth responses. The findings of this study are discussed in terms of generalist versus specialist strategies in long-lived, polyploid, perennial grasses. I conclude that in environments characterised by unpredictable, short-term fluctuations, long-lived species will show adaptation to large-scale, long-term environmental trends only, and adopt a generalist strategy in the face of short-term fluctuations

Physical Activity and Nutrition INfluences In ageing (PANINI): consortium mission statement

First paragraph: Current demographic trends indicate that by the year 2020, almost one in five of the European population will be aged 65 years or over. Although life expectancy is increasing by 2 years per decade, the period of life spent in good health is not keeping pace and most Europeans spend their last decade in poor health. Consequently, there is an urgent need to understand how lifestyle factors can influence age-related changes from gene to society level and how they may be integrated into a net effect of healthy ageing. It is also crucial to develop and validate interventions and health policies to ensure that more of our older adults have a healthy and active later life. This is an urgent and cross-cutting research priority in Europe, and to achieve this, it is vital to increase research capacity in this area to push forward the frontiers of scientific understanding. The Horizon 2020 funded Marie Curie Sklodowska Innovative Training Network—PANINI is addressing this capacity issue by focusing on research and training in two major interacting lifestyle factors with impact at multiple levels, namely, physical activity and nutrition

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Accessory costs of seed production and the evolution of angiosperms

Accessory costs of reproduction frequently equal or exceed direct investment in offspring, and can limit the evolution of small offspring sizes. Early angiosperms had minimum seed sizes, an order of magnitude smaller than their contemporaries. It has been proposed that changes to reproductive features at the base of the angiosperm clade reduced accessory costs thus removing the fitness disadvantage of small seeds. We measured accessory costs of reproduction in 25 extant gymnosperms and angiosperms, to test whether angiosperms can produce small seeds more economically than gymnosperms. Total accessory costs scaled isometrically to seed mass for angiosperms but less than isometrically for gymnosperms, so that smaller seeds were proportionally more expensive for gymnosperms to produce. In particular, costs of abortions and packaging structures were significantly higher in gymnosperms. Also, the relationship between seed:ovule ratio and seed size was negative in angiosperms but positive in gymnosperms. We argue that the carpel was a key evolutionary innovation reducing accessory costs in angiosperms by allowing sporophytic control of pre- and postzygotic mate selection and timing of resource allocation. The resulting reduction in costs of aborting unfertilized ovules or genetically inferior embryos would have lowered total reproductive costs enabling early angiosperms to evolve small seed sizes and short generation times.11 page(s

Accessory costs of seed production

Accessory costs of reproduction are those that are necessary to mature a seed, but that do not involve the direct cost of provisioning the seed itself. This study aims to quantify accessory costs in a range of species, and test whether they decrease as a proportion of total reproductive expenditure with increasing seed mass, as might be expected if economies of scale came into play at larger seed sizes. We also test whether accessory costs varied with growth form, pollination mode, and dispersal mode, with the expectation that biotic pollination and dispersal modes should incur greater costs. Reproductive allocation (dry biomass) over one season, was calculated for 14 diclinous angiosperm species. Accessory costs averaged 73% of total reproductive allocation, with the majority spent on packaging and dispersal. Total accessory costs, packaging and dispersal costs, and costs incurred prior to pollination were proportional to direct costs of reproduction in major axis regressions. However, larger seeded species incurred significantly greater costs associated with aborted seeds and fruits, and matured a smaller proportion of ovules. This is consistent with larger seeded species being more selective of the ovules/embryos matured than small-seeded species. Total accessory costs, and proportion of ovules aborted, were also significantly greater for biotically dispersed species, but only due to an association with larger seed masses. Costs associated with abortions were lower for biotically pollinated species, due to a general trend of more ovules per ovary, resulting in greater cost sharing. This study demonstrates that expenditure on items other than seeds accounts for the majority of reproductive allocation in flowering plants. Yet, far more literature exists on seed mass variation than on investment in accessory structures. We found a proportional relationship between accessory costs and seed mass that warrants further investigation within the context of selection on margin returns on investment.8 page(s

Data from: Human blood and mucosal regulatory T cells express activation markers and inhibitory receptors in inflammatory bowel disease

Background: FOXP3+ regulatory T cells (Tregs) are critical for preventing intestinal inflammation. However, FOXP3+ T cells are paradoxically increased in the intestines of patients with the inflammatory bowel disease (IBD) ulcerative colitis (UC) or Crohn's disease (CD). We determined whether these FOXP3+ cells in IBD patients share or lack the phenotype of such cells from patients without IBD. Methods: We quantified and characterized FOXP3+ Treg populations, as well as FOXP3- CD4+ T cells, in the lamina propria lymphocytes (LPL) of intestine surgically resected from patients with and without IBD, and in the blood of controls or Crohn's patients with or without disease activity. Results: In all samples, a similar fraction of FOXP3+ cells expressed the "natural" Treg (nTreg) marker Helios, suggesting that, in IBD, these cells are not entirely "induced" Tregs (iTregs) derived from activated effector T cells. Helios+ and Helios- FOXP3+ T cells demonstrated similar expression of maturation markers, activation markers, and inhibitory molecules between IBD patients and controls, while FOXP3- cells paradoxically expressed more of the inhibitory receptors CD39, CTLA4, and PD-1 in inflamed mucosa. Greater expression of activation markers was also seen in both Helios+ and Helios- Tregs, relative to FOXP3- cells, in both IBD patients and controls, indicating that Tregs are effectively activated by antigen in IBD. Conclusions: Extensive immunophenotyping revealed that Helios+ and Helios- mucosal Tregs exist at a similar frequency, and have a similar expression of inhibitory molecules and activation markers in patients with IBD as in healthy controls

Comparative transcriptome analysis of the wild-type model apomict Hieracium praealtum and its loss of parthenogenesis (lop) mutant

Abstract Background Asexual seed formation (apomixis) has been observed in diverse plant families but is rare in crop plants. The generation of apomictic crops would revolutionize agriculture, as clonal seed production provides a low cost and efficient way to produce hybrid seed. Hieracium (Asteraceae) is a model system for studying the molecular components of gametophytic apomixis (asexual seed reproduction). Results In this study, a reference transcriptome was produced from apomictic Hieracium undergoing the key apomictic events of apomeiosis, parthenogenesis and autonomous endosperm development. In addition, transcriptome sequences from pre-pollination and post-pollination stages were generated from a loss of parthenogenesis (lop) mutant accession that exhibits loss of parthenogenesis and autonomous endosperm development. The transcriptome is composed of 147,632 contigs, 50% of which were annotated with orthologous genes and their probable function. The transcriptome was used to identify transcripts differentially expressed during apomictic and pollination dependent (lop) seed development. Gene Ontology enrichment analysis of differentially expressed transcripts showed that an important difference between apomictic and pollination dependent seed development was the expression of genes relating to epigenetic gene regulation. Genes that mark key developmental stages, i.e. aposporous embryo sac development and seed development, were also identified through their enhanced expression at those stages. Conclusion The production of a comprehensive floral reference transcriptome for Hieracium provides a valuable resource for research into the molecular basis of apomixis and the identification of the genes underlying the LOP locus

Trophic facilitation in forest restoration: Can Nothofagus trees use ectomycorrhizal fungi of the pioneer shrub Leptospermum?

The benefits of plant-to-plant facilitation in ecological restoration are well recognized, yet the potential for indirect trophic facilitation remains understudied. Nothofagus (southern beech; Nothofagaceae) is an iconic southern hemisphere tree genus that is frequently the focus of ecological restoration efforts. One aspect of Nothofagus ecology that may limit restoration success is the availability of appropriate ectomycorrhizal fungi. It has been suggested that pioneer dual-mycorrhizal hosts such as Leptospermum species (Myrtaceae) could facilitate Nothofagus establishment by providing fungal inoculum, but the capacity for Nothofagus to use Leptospermum ectomycorrhizal fungi is unknown. To investigate potential indirect facilitation, we conducted a common garden pot trial to determine if Nothofagus cliffortioides (mountain beech) can use symbionts from Leptospermum scoparium (m & amacr;nuka) ectomycorrhizal communities. Nothofagus and Leptospermum seedlings were grown in monoculture and mixed pairs with reciprocal "home" and "away" soil fungal inoculum. ITS2 metabarcoding of eDNA from hyphal ingrowth bags revealed that Nothofagus and Leptospermum inoculum contained different ectomycorrhizal fungal communities, but that half of the common ectomycorrhizal taxa identified were found in both soil types, suggesting generalist fungi exist. Nothofagus was able to form associations with some fungal species originating from Leptospermum inoculum, however, probable spore contamination meant that the proportion of root colonization associated with those species was ambiguous. Root ectomycorrhizal colonization rates were positively associated with seedling biomass, and there was some evidence of a home soil inoculum advantage in Nothofagus, but these effects were minor. Additionally, we found evidence that home inoculum provides a protective advantage against drought stress for Leptospermum seedlings. Our results indicate the potential for using Leptospermum to promote Nothofagus establishment in restoration plantings and highlight the possible benefits of considering fungal mutualists in ecological restoration projects.ISSN:2045-775