Ancestral genetic variation in phenotypic plasticity underlies rapid evolutionary changes in resurrected populations of waterfleas.

The role of phenotypic plasticity in adaptive evolution has been debated for decades. This is because the strength of natural selection is dependent on the direction and magnitude of phenotypic responses to environmental signals. Therefore, the connection between plasticity and adaptation will depend on the patterns of plasticity harbored by ancestral populations before a change in the environment. Yet few studies have directly assessed ancestral variation in plasticity and tracked phenotypic changes over time. Here we resurrected historic propagules of Daphnia spanning multiple species and lakes in Wisconsin following the invasion and proliferation of a novel predator (spiny waterflea, Bythotrephes longimanus). This approach revealed extensive genetic variation in predator-induced plasticity in ancestral populations of Daphnia It is unlikely that the standing patterns of plasticity shielded Daphnia from selection to permit long-term coexistence with a novel predator. Instead, this variation in plasticity provided the raw materials for Bythotrephes-mediated selection to drive rapid shifts in Daphnia behavior and life history. Surprisingly, there was little evidence for the evolution of trait plasticity as genetic variation in plasticity was maintained in the face of a novel predator. Such results provide insight into the link between plasticity and adaptation and highlight the importance of quantifying genetic variation in plasticity when evaluating the drivers of evolutionary change in the wild.

Unique maternal and environmental effects on the body morphology of the Least Killifish, Heterandria formosa.

An important step in diagnosing local adaptation is the demonstration that phenotypic variation among populations is at least in part genetically based. To do this, many methods experimentally minimize the environmental effect on the phenotype to elucidate the genetic effect. Minimizing the environmental effect often includes reducing possible environmental maternal effects. However, maternal effects can be an important factor in patterns of local adaptation as well as adaptive plasticity. Here, we report the results of an experiment with males from two populations of the poeciliid fish, Heterandria formosa, designed to examine the relative influence of environmental maternal effects and environmental effects experienced during growth and development on body morphology, and, in addition, whether the balance among those effects is unique to each population. We used a factorial design that varied thermal environment and water chemistry experienced by mothers and thermal environment and water chemistry experienced by offspring. We found substantial differences between the two populations in their maternal and offspring norms of reaction of male body morphology to differences in thermal environment and water chemistry. We also found that the balance between maternal effects and postparturition environmental effects differed from one thermal regime to another and among traits. These results indicate that environmental maternal effects can be decidedly population-specific and, as a result, might either contribute to the appearance of or blur evidence for local adaptation. These results also suggest that local adaptation might also occur through the evolution of maternal norms of reaction to important, and varying, environmental factors.

Variable alterations of the microbiota, without metabolic or immunological change, following faecal microbiota transplantation in patients with chronic pouchitis.

Faecal microbiota transplantation (FMT) is effective in the treatment of Clostridium difficile infection, where efficacy correlates with changes in microbiota diversity and composition. The effects of FMT on recipient microbiota in inflammatory bowel diseases (IBD) remain unclear. We assessed the effects of FMT on microbiota composition and function, mucosal immune response, and clinical outcome in patients with chronic pouchitis. Eight patients with chronic pouchitis (current PDAI ≥7) were treated with FMT via nasogastric administration. Clinical activity was assessed before and four weeks following FMT. Faecal coliform antibiotic sensitivities were analysed, and changes in pouch faecal and mucosal microbiota assessed by 16S rRNA gene pyrosequencing and (1)H NMR spectroscopy. Lamina propria dendritic cell phenotype and cytokine profiles were assessed by flow cytometric analysis and multiplex assay. Following FMT, there were variable shifts in faecal and mucosal microbiota composition and, in some patients, changes in proportional abundance of species suggestive of a "healthier" pouch microbiota. However, there were no significant FMT-induced metabolic or immunological changes, or beneficial clinical response. Given the lack of clinical response following FMT via a single nasogastric administration our results suggest that FMT/bacteriotherapy for pouchitis patients requires further optimisation.

Shape variation in the least killifish: ecological associations of phenotypic variation and the effects of a common garden.

Studies of the adaptive significance of variation among conspecific populations often focus on a single ecological factor. However, habitats rarely differ in only a single ecological factor, creating a challenge for identifying the relative importance of the various ecological factors that might be maintaining local adaptation. Here we investigate the ecological factors associated with male body shape variation among nine populations of the poeciliid fish, Heterandria formosa, from three distinct habitats and combine those results with a laboratory study of three of those populations to assess the contributions of genetic and environmental influences to shape variation. Field-collected animals varied principally in three ways: the orientation of the gonopodium, the intromittent organ; the degree of body depth and streamlining; and the shape of the tail musculature. Fish collected in the spring season were larger and had a more anteriorly positioned gonopodium than fish collected in autumn. Fish collected from lotic springs were larger and more streamlined than those collected from lentic ponds or tidal marshes. Some of the variation in male shape among populations within habitats was associated with population-level variation in species richness, adult density, vegetative cover, predation risk, and female standard length. Population-level differences among males in body size, position of the gonopodium, and shape of the tail musculature were maintained among males reared in a common environment. In contrast, population variation in the degree of streamlining was eliminated when males were reared in a common environment. These results illustrate the complicated construction of multivariate phenotypic variation and suggest that different agents of selection have acted on different components of shape.

Constitutive gut-homing capacity on circulating myeloid dendritic cells in coeliac disease / Capacidad constitutiva del intestino para células dendríticas mieloides circulantes en la enfermedad celiaca

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Lost therapeutic potential of monocyte-derived dendritic cells through lost tissue homing: stable restoration of gut specificity with retinoic acid.

Human monocyte-derived dendritic cells (DC) (MoDC) are utilized for immunotherapy. However, in-vitro immunological effects are often not mirrored in vivo. We studied the tissue-homing potential of MoDC. Circulating monocytes and DC expressed different tissue-homing markers and, during in-vitro development of MoDC, homing marker expression was lost resulting in a 'homeless' phenotype. Retinoic acid (RA) induced gut-homing markers (ß7 and CCR9) and a regulatory phenotype and function [decreased human leucocyte antigen D-related (HLA-DR) and increased ILT3 and fluorescein isothiocyanate (FITC-dextran uptake) in MoDC]. RA-MoDC were less stimulatory and primed conditioned T cells with a gut-homing profile (ß7(+)CLA(-)). Unlike the normal intestinal microenvironment, that from inflamed colon of ulcerative colitis (UC) patients did not induce regulatory properties in MoDC. However, RA-MoDC maintained their regulatory gut-specific properties even in the presence of UC microenvironment. Therefore, MoDC may be ineffectual for immunotherapy because they lack tissue-homing and tissue-imprinting specificity. However, MoDC rehabilitation with gut-homing potential by RA could be useful in promoting immunotherapy in pathologies such as UC.

Skin- and gut-homing molecules on human circulating γδ T cells and their dysregulation in inflammatory bowel disease.

Changes in phenotype and function of γδ T cells have been reported in inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Dysregulation of lymphocyte migration plays a key role in IBD pathogenesis; however, data on migratory properties of γδ T cells are scarce. Human circulating γδ T cells from healthy controls (n = 27), patients with active CD (n = 15), active UC (n = 14) or cutaneous manifestations of IBD (n = 2) were characterized by flow cytometry. Circulating γδ T cells in healthy controls were CD3(hi) and expressed CD45RO. They expressed gut-homing molecule ß7 but not gut-homing molecule corresponding chemokine receptors (CCR)9, or skin-homing molecules cutaneous lymphocyte-associated antigen (CLA) and CCR4, despite conventional T cells containing populations expressing these molecules. CCR9 expression was increased on γδ T cells in CD and UC, while skin-homing CLA was expressed aberrantly on γδ T cells in patients with cutaneous manifestations of IBD. Lower levels of CD3 expression were found on γδ T cells in CD but not in UC, and a lower proportion of γδ T cells expressed CD45RO in CD and UC. Enhanced expression of gut-homing molecules on circulating γδ T cells in IBD and skin-homing molecules in cutaneous manifestations of IBD may be of clinical relevance.

Etiology of pouchitis.

Restorative proctocolectomy with ileal-pouch anal anastomosis (RPC) is the operation of choice for ulcerative colitis (UC) patients requiring surgery. It is also used for patients with familial adenomatous polyposis (FAP). Pouchitis accounts for 10% of pouch failures. It is an idiopathic inflammatory condition that may occur in up to 50% of patients after RPC for UC. It is rarely seen in FAP patients after RPC. The etiology of pouchitis remains unclear. An overlap with UC is suggested by the frequency with which pouchitis affects patients with UC compared with FAP patients. There is significant clinical evidence implicating bacteria in the pathogenesis of pouchitis. Studies using culture and molecular methods demonstrate a dysbiosis of the pouch microbiota in pouchitis. Risk factors, genetic associations, and serological markers of pouchitis suggest that the interactions between the host immune responses and the pouch microbiota underlie the etiology of this idiopathic inflammatory condition. Here we present a detailed review of the data focusing on the pouch microbiota and the immune responses that support this hypothesis. We also discuss the contribution of luminal metabolic factors and the epithelial membrane in the etiology of this inflammatory process. The ileoanal pouch offers a unique opportunity to study the inter-relationships between the gut microbiota and host immune responses from before the onset of disease. For this reason the study of pouchitis could serve as a human model that significantly enhances our understanding of inflammatory bowel diseases in general.

Review article: faecal transplantation therapy for gastrointestinal disease.

BACKGROUND: Evidence is emerging regarding the relationship between a dysbiosis of the human gut microbiota and a number of gastrointestinal diseases as well as diseases beyond the gut. Probiotics have been investigated in many gastrointestinal disease states, with variable and often modest outcomes. Faecal transplantation is an alternative approach to manipulate the gut microbiota. AIM: To review the use of faecal transplantation therapy for the management of gastrointestinal disorders. METHODS: Available articles on faecal transplantation in the management of gastrointestinal disorders were identified using a Pubmed search and bibliographies of review articles on the subject were collated. RESULTS: A total of 239 patients who had undergone faecal transplantation were reported. Seventeen of 22 studies of faecal transplantation were in fulminant or refractory Clostridium difficile. Studies of faecal transplantation are heterogeneous regarding the patients, donors, screening, methods of administration and definition of response. Faecal transplantation for C. difficile has been demonstrated to be effective in 145/166 (87%) patients. Small numbers of patients are reported to have undergone successful faecal transplantation for irritable bowel syndrome and inflammatory bowel disease. CONCLUSIONS: Faecal transplantation has been reported with good outcomes for fulminant and refractory C. difficile. No adverse effects of faecal transplantation have been reported. However, there are no level 1 data of faecal transplantation and reports to date may suffer from reporting bias of positive outcomes and under-reporting of adverse effects. This therapy holds great promise, where a dysbiosis of the gut microbiota is responsible for disease and further studies are necessary to explore this potential.

Synchronous bidirectional endoscopy for iron deficiency anaemia: is it appropriate for patients under 50?

BACKGROUND: UK guidelines1 suggest investigation with bidirectional endoscopy (BDE) (upper endoscopy and colonoscopy) in the same sedative episode is a reasonable approach for the investigation of iron deficiency anaemia. There are few data regarding such investigation for iron deficiency anaemia (IDA) in young men. OBJECTIVE: To assess the use of synchronous BDE for IDA in men and in women <50; and to compare the effectiveness of synchronous BDE in the investigation of iron deficiency anaemia in patients <50 years with those >50 years. METHODS: Our endoscopy database was searched for all synchronous bidirectional endoscopies that were undertaken for the indication of iron deficiency anaemia between 2003 and 2009. Age, gender and endoscopic findings were retrieved for each procedure. Significant findings were defined as cancer, grade 3 oesophagitis (Savory Miller classification), oesophageal stricture, Barrett's oesophagus, ulcer, arteriovenous malformation, colitis, and colonic polyps >1 cm. RESULTS: 558 patients underwent synchronous BDE for iron deficiency anaemia between 2003 and 2009. A significant finding in those >50 years was found in 24.6% vs 11.3% of patients <50 years (OR 2.5, 95% CI 1.3 to 5.0). In men under 50 years a significant finding was present in 20.6%. Dual pathology was present in 1.5% of patients over 50 vs 1.3% under 50 years. CONCLUSIONS: Our findings suggest that synchronous BDE is an appropriate means of investigation for iron deficiency anaemia in patients >50 and for men <50 years old.

A utility analysis correlation with visual acuity: methodologies and vision in the better and poorer eyes.

OBJECTIVE: To ascertain the correlation between visual acuity levels and ophthalmic utility values obtained using time tradeoff and standard gamble utility analysis methodologies. METHODS: Three hundred twenty-five consecutive patients with visual loss to 20/40 or less in at least one eye with predominantly vitreoretinal pathology were evaluated in a cross-sectional fashion using a standardized testing methodology to obtain ophthalmic time tradeoff and standard gamble utility values. Spearman correlation coefficients were employed to correlate the utility values with visual acuity in better seeing and poorer seeing eyes. RESULTS: The Spearman correlation coefficient for time tradeoff utility values and vision in the better seeing eye was 0.455 (p < 0.001), while that for time tradeoff utility values and visual acuity in the poorer seeing eye was 0.268 (p < 0.001). The coefficient for standard gamble utility values and the better seeing eye was 0.371 (p < 0.001), while that for standard gamble utility values and vision in the poorer seeing eye was 0.250 (p < 0.001). CONCLUSIONS: There is a greater correlation between ophthalmic utility values and vision in the better seeing eye, as versus vision in the poorer seeing eye. Time tradeoff ophthalmic utility values demonstrate a greater correlation with vision in the better seeing eye than do standard gamble utility values.