Phenotypic Divergence of Indigenous and Translocated Arctic Charr (Salvelinus alpinus) Populations in Maine

Selection on traits related to trophic ecology is recognized as an important contributing factor in adaptive divergence and speciation. For several freshwater fish species, including Arctic charr (Salvelinus alpinus), such selection is commonly reflected in relationships between diet, habitat use and phenotypic divergence. Trophic specializations that emerge have been extensively studied among sympatric forms, but much less is known of the extent of this type of divergence in allopatry. Trait differences among these forms are also thought to reflect thousands of years of evolution, making it difficult to examine root causes of such divergence in natural populations. Here, I address the hypotheses that selection on trophic characters is important to incipient stages of divergence and the maintenance of specialized forms in allopatry, using indigenous and recently translocated populations of Arctic charr in Maine. To address this, I compared aspects of body shape, gill raker morphology, growth, and diet among six populations, including one transplant and its ancestral source. This examination revealed the presence of at least three trophic forms among Maine charr, including a benthic specialist not previously identified in this region. Differences observed among these populations were analogous to those typical of trophic forms found elsewhere in sympatry, though perhaps less extensive in scale. Divergence between a translocated population and its source suggest some aspects of specialization are labile in contemporary time. In combination, these results indicate trophic ecology may play an important role in all stages of adaptive divergence, and niche stability may be important in maintaining trophic specializations over longer periods of time. In light of this new information, I also suggest that management plans for this species in Maine should seek to incorporate more information about such specialized forms, and should employ ecosystem based management to preserve forms within the unique contexts of their respective lake systems. Management approaches that fail to preserve lake community structure in situ are likely to result in either extinctions or revisions of specializations

Occurrence of Lake Chub, Couesius plumbeus, in Northern Labrador

Lake Chub (Couesius plumbeus) were recently found in seven previously undocumented locations in northern Labrador. These populations represent the first recorded accounts of this species in the Labrador region north of the Churchill River drainage and east of the George River. Lake Chub likely invaded this region via dispersal routes provided by eastern spillways of glacial Lake Naskaupi

Integrative analysis of RUNX1 downstream pathways and target genes

Background: The RUNX1 transcription factor gene is frequently mutated in sporadic myeloid and lymphoid leukemia through translocation, point mutation or amplification. It is also responsible for a familial platelet disorder with predisposition to acute myeloid leukemia (FPD-AML). The disruption of the largely unknown biological pathways controlled by RUNX1 is likely to be responsible for the development of leukemia. We have used multiple microarray platforms and bioinformatic techniques to help identify these biological pathways to aid in the understanding of why RUNX1 mutations lead to leukemia. Results: Here we report genes regulated either directly or indirectly by RUNX1 based on the study of gene expression profiles generated from 3 different human and mouse platforms. The platforms used were global gene expression profiling of: 1) cell lines with RUNX1 mutations from FPD-AML patients, 2) over-expression of RUNX1 and CBF[Beta], and 3) Runx1 knockout mouse embryos using either cDNA or Affymetrix microarrays. We observe that our datasets (lists of differentially expressed genes) significantly correlate with published microarray data from sporadic AML patients with mutations in either RUNX1 or its cofactor, CBF[Beta]. A number of biological processes were identified among the differentially expressed genes and functional assays suggest that heterozygous RUNX1 point mutations in patients with FPD-AML impair cell proliferation, microtubule dynamics and possibly genetic stability. In addition, analysis of the regulatory regions of the differentially expressed genes has for the first time systematically identified numerous potential novel RUNX1 target genes. Conclusion: This work is the first large-scale study attempting to identify the genetic networks regulated by RUNX1, a master regulator in the development of the hematopoietic system and leukemia. The biological pathways and target genes controlled by RUNX1 will have considerable importance in disease progression in both familial and sporadic leukemia as well as therapeutic implications

Home food preparation practices, experiences and perceptions: A qualitative interview study with photo-elicitation

Food-related choices have an important impact on health. Food preparation methods may be linked to diet and health benefits. However, the factors influencing people’s food choices, and how they are shaped by food preparation experiences, are still not fully understood. We aimed to study home food preparation practices, experiences and perceptions amongst adults in North East England. A matrix was used to purposively sample participants with diverse socio-demographic characteristics. Participants developed photographic food diaries that were used as prompts during semi-structured interviews. Data were analysed using the Framework Method. Interviews were conducted with 18 adults (five men and 13 women), aged approximately 20 to 80 years, to reach data saturation. Participants’ practices varied widely, from reliance on pre-prepared foods, to preparing complex meals entirely from basic ingredients. Key themes emerged regarding the cook (identity), the task (process of cooking), and the context (situational drivers). Resources, in terms of time, money and facilities, were also underpinning influences on food preparation. Participants’ practices were determined by both personal motivations to cook, and the influence of others, and generally reflected compromises between varied competing demands and challenges in life. Most people appeared to be overall content with their food preparation behaviour, though ideally aspired to cook more frequently, using basic ingredients. This often seemed to be driven by social desirability. Home food preparation is complex, with heterogeneous practices, experiences and perceptions both between individuals and within the same individual over time, according to shifting priorities and circumstances. Generalisability of these findings may be limited by the regional participant sample; however the results support and build upon previous research. Focussing interventions on life transition points at which priorities and circumstances change, with careful targeting to stimulate personal motivation and social norms, may prove effective in encouraging home food preparation.This report is independent research arising from a Doctoral Research Fellowship Grant DRF-2014-07-020 for the lead author (SM), supported by the National Institute for Health Research. JA and MW received funding from the Centre for Diet and Activity Research (CEDAR), a UK Clinical Research Collaboration (UKCRC) Public Health Research Centre of Excellence. HB and SM are members of Fuse, also a UKCRC Public Health Research Centre of Excellence. Grant reference number is MR/K02325X/1. Funding for CEDAR and for Fuse from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research and the Wellcome Trust, under the auspices of the UKCRC, is gratefully acknowledged. The views expressed in this publication are those of the authors and not necessarily those of the National Health Service, the Department of Health, the funders or UKCRC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Physical and Biological Factors Affecting Mercury and Perfluorinated Contaminants in Arctic Char (Salvelinus alpinus) of Pingualuit Crater Lake (Nunavik, Canada) + Supplementary Appendices (See Article Tools)

Pingualuk Lake fills a deep crater in the Parc National des Pingualuit on the Ungava Peninsula (Nunavik, Canada) and is isolated from nearby surface waters. The main objectives of this study were to determine and compare the concentrations of two atmospherically derived contaminants, mercury and perfluorinated chemicals (PFCs), in the lake water column and fish of Pingualuk Lake and to assess the physical and biological factors influencing contaminant concentrations. Mercury concentrations in arctic char muscle tissue were comparable to those of char in other Arctic lakes, while the total amount of PFCs was below reported levels for remote lakes in the Arctic and elsewhere. Stable isotope and stomach content analyses were made to investigate the feeding ecology of the Pingualuk Lake arctic char population and indicated the possibility of multiple feeding groups. Genetics characteristics (MH and mtDNA) of fish from Pingualuk Lake revealed that this population is likely distinct from that of nearby Laflamme Lake. However, both arctic char populations exhibit differential variation of their allele families. Physical characteristics determined for Lake Pingualuk revealed that the water column was inversely stratified beneath the ice and extremely transparent to visible and ultraviolet radiation. The highest mercury concentrations (3 – 6 pg mL-1 TH g) occurred just beneath the ice surface in each lake. Pingualuk Lake, given its near pristine state and exceptional limnological features, may serve as a most valuable reference ecosystem for monitoring environmental stressors, such as contaminants, in the Arctic.Le lac Pingualuk, qui remplit un cratère profond situé dans le parc national des Pingualuit, dans la péninsule d’Ungava (Nunavik, Canada), est isolé des eaux de surface avoisinantes. Les principaux objectifs de la présente étude consistaient à déterminer et à comparer les concentrations de deux contaminants dérivés dans l’atmosphère, soit le mercure et les produits chimiques perfluorés, se trouvant dans la colonne d’eau lacustre et les poissons du lac Pingualuk, ainsi qu’à évaluer les facteurs physiques et biologiques influençant les concentrations de contaminants. Les concentrations de mercure décelées dans le tissu musculaire de l’omble chevalier étaient comparables à celles de l’omble d’autres lacs de l’Arctique, tandis que la quantité totale de produits chimiques perfluorés était inférieure aux niveaux répertoriés dans les lacs éloignés de l’Arctique et d’ailleurs. L’analyse des isotopes stables de même que l’analyse du contenu de l’estomac ont permis d’enquêter sur l’écologie alimentaire de la population d’ombles chevaliers du lac Pingualuk, et ont indiqué la possibilité qu’il existe plusieurs groupes d’alimentation. Les caractéristiques génétiques (MH et ADN mt) des poissons du lac Pingualuk ont révélé que cette population est vraisemblablement distincte de celle du lac Laflamme situé tout près. Toutefois, les deux populations d’ombles chevaliers affichent une variation allélique différentielle. Les caractéristiques physiques déterminées dans le cas du lac Pingualuk ont révélé que la colonne d’eau était inversement stratifiée sous la glace et extrêmement transparente au rayonnement visible et au rayonnement ultraviolet. Les concentrations de mercure les plus prononcées (3 – 6 pg mL-1 TH g) se trouvaient juste sous la surface de glace de chaque lac. Étant donné l’état quasi originel et les caractéristiques limnologiques exceptionnelles du lac Pingualuk, ce lac pourrait servir d’écosystème de référence des plus précieux pour surveiller les agresseurs environnementaux, tels que les contaminants, dans l’Arctique

Water chemistry, and biological traits and mercury content of Salvelinus alpinus and S. namaycush in Laflamme and Pingualuit lake

Pingualuk Lake fills a deep crater in the Parc National des Pingualuit on the Ungava Peninsula (Nunavik, Canada) and is isolated from nearby surface waters. The main objectives of this study were to determine and compare the concentrations of two atmospherically derived contaminants, mercury and perfluorinated chemicals (PFCs), in the lake water column and fish of Pingualuk Lake and to assess the physical and biological factors influencing contaminant concentrations. Mercury concentrations in arctic char muscle tissue were comparable to those of char in other Arctic lakes, while the total amount of PFCs was below reported levels for remote lakes in the Arctic and elsewhere. Stable isotope and stomach content analyses were made to investigate the feeding ecology of the Pingualuk Lake arctic char population and indicated the possibility of multiple feeding groups. Genetics characteristics (MH and mtDNA) of fish from Pingualuk Lake revealed that this population is likely distinct from that of nearby Laflamme Lake. However, both arctic char populations exhibit differential variation of their allele families. Physical characteristics determined for Lake Pingualuk revealed that the water column was inversely stratified beneath the ice and extremely transparent to visible and ultraviolet radiation. The highest mercury concentrations (3- 6 pg/mL THg) occurred just beneath the ice surface in each lake. Pingualuk Lake, given its near pristine state and exceptional limnological features, may serve as a most valuable reference ecosystem for monitoring environmental stressors, such as contaminants, in the Arctic

(Table 1) Age, fork length, tissue d15N and δ¹³C and mercury content of arctic char (Salvelinus alpinus) across the Canadian Arctic

Among-lake variation in mercury (Hg) concentrations in landlocked Arctic char was examined in 27 char populations from remote lakes across the Canadian Arctic. A total of 520 landlocked Arctic char were collected from 27 lakes, as well as sediments and surface water from a subset of lakes in 1999, 2002, and 2005 to 2007. Size, length, age, and trophic position (d15N) of individual char were determined and relationships with total Hg (THg) concentrations investigated, to identify a common covariate for adjustment using analysis of covariance (ANCOVA). A subset of 216 char from 24 populations was used for spatial comparison, after length-adjustment. The influence of trophic position and food web length and abiotic characteristics such as location, geomorphology, lake area, catchment area, catchment-to-lake area ratio of the lakes on adjusted THg concentrations in char muscle tissue were then evaluated. Arctic char from Amituk Lake (Cornwallis Island) had the highest Hg concentrations (1.31 µg/g wet wt), while Tessisoak Lake (Labrador, 0.07 µg/g wet wt) had the lowest. Concentrations of THg were positively correlated with size, d15N, and age, respectively, in 88,71, and 58% of 24 char populations. Length and d15N were correlated in 67% of 24 char populations. Food chain length did not explain the differences in length-adjusted THg concentrations in char. No relationships between adjusted THg concentrations in char and latitude or longitude were found, however, THg concentrations in char showed a positive correlation with catchment-to-lake area ratio. Furthermore, we conclude that inputs from the surrounding environment may influence THg concentrations, and will ultimately affect THg concentrations in char as a result of predicted climate-driven changes that may occur in Arctic lake watersheds