Ancient DNA Reveals Genetic Continuity in Mountain Woodland Caribou of the Mackenzie and Selwyn Mountains, Northwest Territories, Canada

We examine the mitochondrial genetic stability of mountain woodland caribou (Rangifer tarandus caribou) in the Mackenzie and Selwyn Mountains, Northwest Territories, over the last 4000 years. Unlike caribou populations in the Yukon, populations in the Northwest Territories show no evidence for mitochondrial genetic turnover during that period, which indicates that they were not adversely affected by the widespread deposition of the White River tephra around 1200 years ago. We detect moderate genetic differentiation between mountain woodland and barren-ground caribou in both territories, lending support to the current subspecies designations. In addition, we identify moderate genetic differentiation between Northwest Territories and western Yukon mountain woodland caribou, suggesting that there has been minimal mixing of matrilines between these herds.Nous examinons la stabilité génétique mitochondriale des caribous des bois des montagnes (Rangifer tarandus caribou) qui ont évolué dans les monts Mackenzie et dans la chaîne de Selwyn, Territoires du Nord-Ouest, ces 4 000 dernières années. Contrairement aux populations de caribou du Yukon, les populations de caribou des Territoires du Nord-Ouest ne montrent aucun signe de rotation génétique mitochondriale pendant cette période, ce qui indique qu’ils n’ont pas été affectés de manière défavorable par le dépôt à grande échelle du téphra de la rivière White, il y a environ 1 200 ans. Nous détectons une différentiation génétique modérée entre le caribou des bois des montagnes et le caribou de la toundra dans les deux territoires, ce qui vient appuyer les désignations actuelles de sous-espèces. Par ailleurs, nous avons dénoté une différenciation génétique modérée entre le caribou des bois des montagnes des Territoires du Nord-Ouest et celui de l’ouest du Yukon, ce qui laisse croire qu’il y aurait eu peu de mélanges matrilinéaires entre ces troupeaux

Predominant expression of Alzheimer’s disease-associated BIN1 in mature oligodendrocytes and localization to white matter tracts

BIN1 is not expressed in human brain microglial cells. (A) Immunohistochemical staining of adjacent sections of normal human brain cortex with antibodies against BIN1 or Iba1 reveals that BIN1 immunoreactive cells that are morphologically distinct from microglia. The boxed region is shown at a higher magnification on the right. (B) Single and two-color immunostaining of the human brain using antibodies against BIN1 and CD45 reveals that perivenular CD45-positive cells of the hematopoietic lineage do not express BIN1. (TIFF 4392 kb

Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms

A central question in lignin biosynthesis is how guaiacyl intermediates are hydroxylated and methylated to the syringyl monolignol in angiosperms. To address this question, we cloned cDNAs encoding a cytochrome P450 monooxygenase (LsM88) and a caffeate O-methyltransferase (COMT) from sweetgum (Liquidambar styraciflua) xylem. Mass spectrometry-based functional analysis of LsM88 in yeast identified it as coniferyl aldehyde 5-hydroxylase (CAld5H). COMT expressed in Escherichia coli methylated 5-hydroxyconiferyl aldehyde to sinapyl aldehyde. Together, CAld5H and COMT converted coniferyl aldehyde to sinapyl aldehyde, suggesting a CAld5H/COMT-mediated pathway from guaiacyl to syringyl monolignol biosynthesis via coniferyl aldehyde that contrasts with the generally accepted route to sinapate via ferulate. Although the CAld5H/COMT enzyme system can mediate the biosynthesis of syringyl monolignol intermediates through either route, k(cat)/K(m) of CAld5H for coniferyl aldehyde was ≈140 times greater than that for ferulate. More significantly, when coniferyl aldehyde and ferulate were present together, coniferyl aldehyde was a noncompetitive inhibitor (K(i) = 0.59 μM) of ferulate 5-hydroxylation, thereby eliminating the entire reaction sequence from ferulate to sinapate. In contrast, ferulate had no effect on coniferyl aldehyde 5-hydroxylation. 5-Hydroxylation also could not be detected for feruloyl-CoA or coniferyl alcohol. Therefore, in the presence of coniferyl aldehyde, ferulate 5-hydroxylation does not occur, and the syringyl monolignol can be synthesized only from coniferyl aldehyde. Endogenous coniferyl, 5-hydroxyconiferyl, and sinapyl aldehydes were detected, consistent with in vivo operation of the CAld5H/COMT pathway from coniferyl to sinapyl aldehydes via 5-hydroxyconiferyl aldehyde for syringyl monolignol biosynthesis

Detection of Mycobacterium avium subspecies paratuberculosis in several herds of Arctic Caribou (Rangifer tarandus ssp.)

Mycobacterium avium subspecies paratuberculosis (MAP) is a common pathogen in domestic ruminants that causes granulomatous inflammation of the small intestine leading to emaciation and wasting. Clinical disease (Johne's disease) is also reported for several wild ruminant species. Between 2007 and 2009 we collected 561 fecal samples from caribou (Rangifer tarandus ssp.) representing 10 herds of migratory caribou, two herds of caribou from Greenland, and three populations of boreal woodland caribou. Feces were tested for MAP by bacterial culture and PCR targeting the IS900 insertion sequence. In total, 31 samples from eight different populations representing all three ecotypes were found positive for MAP by PCR, with one sample from the Rivière-aux-Feuilles herd also being culture positive for the type II (cattle) strain. The proportion of positive animals was particularly high in the Akia-Maniitsoq herd in Greenland, and Rivière-aux-Feuilles and Riviè re-George herds in northeastern Canada (23.4, 11.5, and 10.0%, respectively). Our results indicate that MAP is present in several caribou herds of different ecotypes in northern Canada and Greenland and that MAP circulates within wildlife populations that do not have ongoing contact with domestic livestock. The epidemiology, pathogenicity, and effects on the health of caribou in northern ecosystems remain unknown

Detection of Mycobacterium avium subspecies paratuberculosis in several herds of arctic caribou (Rangifer tarandus ssp.)

Mycobacterium avium subspecies paratuberculosis (MAP) is a common pathogen in domestic ruminants that causes granulomatous inflammation of the small intestine leading to emaciation and wasting. Clinical disease (Johne’s disease) is also reported for several wild ruminant species. Between 2007 and 2009 we collected 561 fecal samples from caribou (Rangifer tarandus ssp.) representing 10 herds of migratory caribou, two herds of caribou from Greenland, and three populations of boreal woodland caribou. Feces were tested for MAP by bacterial culture and PCR targeting the IS900 insertion sequence. In total, 31 samples from eight different populations representing all three ecotypes were found positive for MAP by PCR, with one sample from the Rivière-aux-Feuilles herd also being culture positive for the type II (cattle) strain. The proportion of positive animals was particularly high in the Akia-Maniitsoq herd in Greenland, and Rivière-aux-Feuilles and Rivière-George herds in northeastern Canada (23.4, 11.5, and 10.0%, respectively). Our results indicate that MAP is present in several caribou herds of different ecotypes in northern Canada and Greenland and that MAP circulates within wildlife populations that do not have ongoing contact with domestic livestock. The epidemiology, pathogenicity, and effects on the health of caribou in northern ecosystems remain unknown

Detection of Mycobacterium avium subspecies paratuberculosis in several herds of Arctic Caribou (Rangifer tarandus ssp.)

Mycobacterium avium subspecies paratuberculosis (MAP) is a common pathogen in domestic ruminants that causes granulomatous inflammation of the small intestine leading to emaciation and wasting. Clinical disease (Johne's disease) is also reported for several wild ruminant species. Between 2007 and 2009 we collected 561 fecal samples from caribou (Rangifer tarandus ssp.) representing 10 herds of migratory caribou, two herds of caribou from Greenland, and three populations of boreal woodland caribou. Feces were tested for MAP by bacterial culture and PCR targeting the IS900 insertion sequence. In total, 31 samples from eight different populations representing all three ecotypes were found positive for MAP by PCR, with one sample from the Rivière-aux-Feuilles herd also being culture positive for the type II (cattle) strain. The proportion of positive animals was particularly high in the Akia-Maniitsoq herd in Greenland, and Rivière-aux-Feuilles and Riviè re-George herds in northeastern Canada (23.4, 11.5, and 10.0%, respectively). Our results indicate that MAP is present in several caribou herds of different ecotypes in northern Canada and Greenland and that MAP circulates within wildlife populations that do not have ongoing contact with domestic livestock. The epidemiology, pathogenicity, and effects on the health of caribou in northern ecosystems remain unknown

DAG and TAG molecular species as well as acyl-CoA pool under replete and N-deplete conditions.

<p>The amounts of the molecular species of diacylglycerol (DAG) und triacylglycerol (TAG) are displayed with a threshold of 0.1 μmol/g in (A). These data were produced by neutral loss scanning which allows the determination of the sum (number of carbon atoms and of double bonds) of two (for DAG) or three FAs (for TAG) but not always the elucidation of the distinct fatty acid composition of the molecular species. Therefore, the possible fatty acid composition of the different molecular species are given in (B). (C): The diagrams show the acyl-CoA pool as comparison of day 0 (beige) and the last day of the growth kinetic of growth under replete conditions (blue), N-depletion with normal light (red) and N-depletion with high light (green). Data are mean values of 3 biological replicates, for the comprised time point 0d, 9 biological replicates were used. Error bars indicate standard deviation.</p

CNS fibroblasts form a fibrotic scar in response to immune cell infiltration.

Fibrosis is a common pathological response to inflammation in many peripheral tissues and can prevent tissue regeneration and repair. Here, we identified persistent fibrotic scarring in the CNS following immune cell infiltration in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Using lineage tracing and single-cell sequencing in EAE, we determined that the majority of the fibrotic scar is derived from proliferative CNS fibroblasts, not pericytes or infiltrating bone marrow-derived cells. Ablating proliferating fibrotic cells using cell-specific expression of herpes thymidine kinase led to an increase in oligodendrocyte lineage cells within the inflammatory lesions and a reduction in motor disability. We further identified that interferon-gamma pathway genes are enriched in CNS fibrotic cells, and the fibrotic cell-specific deletion of Ifngr1 resulted in reduced fibrotic scarring in EAE. These data delineate a framework for understanding the CNS fibrotic response

Growth parameters and total fatty acid composition of <i>Phaeodactylum tricornutum</i> control cultures under normal light (blue) or with N-depletion under normal light (red) or high light (green).

<p>In (A) the dry weight content [mg/ml] is depicted and in (B) the chlorophyll <i>a</i> amount in relation to the dry weight [mg/g]. Samples were taken at days 0, 2, 5 and 7 for N-replete growth and at days 0, 2, 3 and 6 for N-depleted growth. These samples were used for determination of growth parameters as well as for lipid and metabolite analysis. The total FA composition in μmol/g is displayed in (C) showing day 0 and the last time point of each condition. Day 0 comprises the mean of all conditions (beige). Day 7 of replete conditions is shown in blue, day 6 of N-deplete with normal light in red and day 6 of N-deplete with high light in green. Data are mean values of 3 biological replicates, for the comprised time point 0d, 4 biological replicates were used. Error bars indicate standard deviation.</p