Showing papers on "Mink published in 2006"
TL;DR: This hypothesis was tested using concomitant mutagenesis in KCNQ1 and in the membrane‐localized ‘activation triplet’ regions of MinK and MiRP2 to identify pairs of residues that interact to control KCnQ1 activation and suggests specifically that two of the interactions are required for the contrasting gating effects of Mink and Mi RP2.
Abstract: KCNQ1 alpha subunits form functionally distinct potassium channels by coassembling with KCNE ancillary subunits MinK and MiRP2. MinK-KCNQ1 channels generate the slowly activating, voltage-dependent cardiac IKs current. MiRP2-KCNQ1 channels form a constitutively active current in the colon. The structural basis for these contrasting channel properties, and the mechanisms of alpha subunit modulation by KCNE subunits, are not fully understood. Here, scanning mutagenesis located a tryptophan-tolerant region at positions 338-340 within the KCNQ1 pore-lining S6 domain, suggesting an exposed region possibly amenable to interaction with transmembrane ancillary subunits. This hypothesis was tested using concomitant mutagenesis in KCNQ1 and in the membrane-localized 'activation triplet' regions of MinK and MiRP2 to identify pairs of residues that interact to control KCNQ1 activation. Three pairs of mutations exerted dramatic effects, ablating channel function or either removing or restoring control of KCNQ1 activation. The results place KCNE subunits close to the KCNQ1 pore, indicating interaction of MiRP2-72 with KCNQ1-338; and MinK-59,58 with KCNQ1-339, 340. These data are consistent either with perturbation of the S6 domain by MinK or MiRP2, dissimilar positioning of MinK and MiRP2 within the channel complex, or both. Further, the results suggest specifically that two of the interactions, MiRP2-72/KCNQ1-338 and MinK-58/KCNQ1-340, are required for the contrasting gating effects of MinK and MiRP2.
101 citations
TL;DR: A role for minK and eNOS genes as predisposing factors to NVAF is suggested and a role for dominant, recessive, and additive model models is suggested.
Abstract: Aim Mink protein, a β-subunit of Iks potassium channels modulate cardiac cellular electrophysiology, and experimental data demonstrated that NO is involved in cardiac vagal activity and in the inhibition of sympathetic activity. We evaluated the role of eNOS −786T>C, 894G>T, 4a/4b and of minK S38G polymorphisms as predisposing factors to non-valvular atrial fibrillation (NVAF).
Methods and results We studied 331 consecutive patients with documented NVAF and in 441 control subjects, comparable for age and gender. A significant difference in allele frequencies between patients and controls for minK S38G and eNOS −786T>C, but not for eNOS 894G>T and 4a/4b polymorphisms, was observed. The minK 38G allele was significantly associated with susceptibility to NVAF at both univariate and multivariable analysis, according to dominant and recessive genetic model (multivariable analysis, dominant: OR=1.73, P =0.004 and recessive: OR=1.59, P =0.006). The eNOS −786C allele weakly influenced NVAF at univariate analysis, according to the dominant model (OR=1.50, P =0.01). The contemporary presence of minK 38G and eNOS −786C alleles increased the predisposition to NVAF, after adjustment with cardiovascular risk factors (OR minK 38G* eNOS −786C=2.11, P <0.0001; OR=2.58, P =0.003; OR=3.08, P =0.002, according to dominant, recessive, and additive model, respectively).
Conclusion Our findings suggest a role for minK and eNOS genes as predisposing factors to NVAF.
81 citations
TL;DR: It is demonstrated that ecologically relevant exposures to MeHg (i.e., 0.5 ppm in diet) have the potential to alter the cholinergic system in specific brain regions and highlight the autoregulatory nature of cholin neurotransmission.
77 citations
TL;DR: Responses of amphibian populations in the outer Finnish Archipelago to a long-term, large-scale removal of American mink, an invasive predator linked to recent biodiversity loss across Europe, are reported.
Abstract: Amphibians are undergoing enigmatic global declines variously attributed to a complex web of anthropogenic forces. Alien predators pose a fundamental threat to biodiversity generally that is predicted to be most acute in island ecosystems. While amphibian eggs and tadpoles are vulnerable to aquatic predators, the effect of predators on adult, reproducing frogs, which most influence amphibian population processes, is unknown. Here, we report on the responses of amphibian populations in the outer Finnish Archipelago to a long-term, large-scale removal of American mink (Mustela vison Schreb.), an invasive predator linked to recent biodiversity loss across Europe. Removal increased both the densities and distribution of common frogs (Rana temporaria L.) but not those of common toads (Bufo bufo L.), which appear to escape mink predation because of their unpalatable skin. Importantly, the largest benefits of mink removal to frog recovery were slow to appear as frogs apparently have a delayed maturation in these harsh environments, which means we must be cautious about reliance upon short-term results.
64 citations
TL;DR: Munks are able to preserve a low melting point and fluidity of the subcutaneous fat depots, which would be essential to a Northern semi-aquatic mammal, as well as preserve the number of double bonds in the FA chain, which correlated positively with mobilization rate in the retroperitoneal fat.
Abstract: The mobilization of fatty acids (FAs) during food deprivation is a selective process in laboratory rodents and humans. The site-specific differences in adipose tissue functions – e.g. energy storage versus insulation – should also affect the use of different FAs. To study this, 16 female minks were randomly assigned into the control group or fasted for 5 days. Preferential mobilization of n-3 polyunsaturated FAs (PUFAs) during fasting caused a decrease in the n-3/n-6 PUFA ratio in fat and liver. In addition, the minks utilized short-chain FAs efficiently in all fat depots, but long-chain FAs – 20:0, 20:1n-11, 20:1n-9, 22:1n-11 and 24:1n-9 – were preserved. The number of double bonds in the FA chain correlated positively with mobilization rate in the retroperitoneal fat. The observed negative correlation between mobilization rate and the location of the first double bond from the methyl end may be due to peroxisomal chain-shortening of long-chain FAs and not the double bond position per se. As a result, minks are able to preserve a low melting point and fluidity of the subcutaneous fat depots, which would be essential to a Northern semi-aquatic mammal.
46 citations
TL;DR: Because inclusion of PCB-contaminated fish that composed approximately 1% of the diet would reduce mink kit survival by 20% or more, it is likely that consumption of up to 30-fold that quantity of HR fish, as could be expected for wild mink, would have an adverse effect on wild minks populations.
Abstract: We evaluated the effects of feeding farm-raised mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)-contaminated fish from the Housatonic River (HR; Berkshire County, MA, USA) on adult reproductive performance and kit growth and survival. Diets contained 0.22–3.54% HR fish, providing 0.34–3.7 μg total PCBs (TPCB)/g feed wet wt (3.5–68.5 pg toxic equivalence [TEQ]/g). Female mink were fed diets before breeding through weaning of kits. Twelve kits from each treatment were maintained on their respective diets for an additional 180 d. Dietary PCBs had no effect on the number of offspring produced, gestation period, or other measures of adult reproductive performance. Mink kits exposed to 3.7 μg TPCB/g feed (68.5 pg TEQ/g) in utero and during lactation had reduced survivability between three and six weeks of age. The lethal concentrations to 10 and 20% of the population (LC10 and LC20, respectively) were estimated to be 0.231 and 0.984 μg TPCB/g feed, respectively. Because inclusion of PCB-contaminated fish that composed approximately 1% of the diet would reduce mink kit survival by 20% or more, it is likely that consumption of up to 30-fold that quantity of HR fish, as could be expected for wild mink, would have an adverse effect on wild mink populations.
45 citations
TL;DR: The results suggest that the decline of mink is related to an increase in the native otter population through interspecific competition, although at a local level also other factors may be important.
36 citations
TL;DR: The hypothesis that mink populations subject to culling have a higher proportion of young (less than 1 year old) to adults compared with non-culled populations is supported.
Abstract: Demographic data on an invasive species of management concern, the American mink, are presented. Data were obtained on three feral mink populations in Europe distinguished by differences in the time elapsed since population establishment. 2. Demographic data are presented in the form of life tables, age-sex distributions and sex ratios. Mink lived a maximum of 6 years, and mortality of 1-year-olds and adults differed substantially between populations. 3. The data support the hypothesis that mink populations subject to culling have a higher proportion of young (less than 1 year old) to adults compared with non-culled populations.
35 citations
TL;DR: It is demonstrated that intracerebrally inoculated cattle not only amplify TME PrPres but also develop clinical CNS signs and extensive lesions of SE, which has not been shown with other TSE agents similarly inoculated into cattle.
Abstract: To compare clinicopathologic findings of transmissible mink encephalopathy (TME) with other transmissible spongiform encephalopathies (TSE, prion diseases) that have been shown to be experimentally transmissible to cattle (sheep scrapie and chronic wasting disease (CWD)), two groups of calves (n 5 4 each) were intracerebrally inoculated with TME agents from two different sources (mink with TME and a steer with TME). Two uninoculated calves served as controls. Within 15.3 months postinoculation, all animals from both inoculated groups developed clinical signs of central nervous system (CNS) abnormality; their CNS tissues had microscopic spongiform encephalopathy (SE); and abnormal prion protein (PrP res ) as detected in their CNS tissues by immunohistochemistry (IHC) and Western blot (WB) techniques. These findings demonstrate that intracerebrally inoculated cattle not only amplify TME PrP res but also develop clinical CNS signs and extensive lesions of SE. The latter has not been shown with other TSE agents (scrapie and CWD) similarly inoculated into cattle. The findings also suggest that the diagnostic techniques currently used for confirmation of bovine spongiform encephalopathy (BSE) would detect TME in cattle should it occur naturally. However, it would be a diagnostic challenge to differentiate TME in cattle from BSE by clinical signs, neuropathology, or the presence of PrP res by IHC and WB.
34 citations
TL;DR: It is possible that consumption of up to 30-fold that quantity of HR fish, as could be expected for wild mink, would result in more severe lesions characterized by loss of teeth, thus impacting survivability.
Abstract: The effects of feeding ranch mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)-contaminated fish (88 gold fish [Carassius auratus] weighing a total of 70.3 kg and 16 carp [Cyprinus carpio] weighing a total of 77.3 kg) collected from the Housatonic River (HR; Berkshire County, MA, USA) in October 1999 on organ weights and histology and hepatic concentrations of total PCBs (ΣPCBs) and 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalence (TEQ) were evaluated. Diets contained 0.22 to 3.54% HR fish, which provided 0.34 to 3.7 μg ΣPCBs/g feed (3.5-69 pg TEQ/g feed). Female mink were fed the diets eight weeks before breeding through weaning of kits at six weeks of age. Offspring were maintained on their respective diets for an additional 180 d. The dietary concentration of PCBs that caused a decrease in kit survival (3.7 μg ΣPCBs/g feed [69 pg TEQ/g]) resulted in a maternal hepatic concentration of 3.1 μg ΣPCBs/g wet weight (218 pg TEQ/g). Organ weights were not consistently affected. Mandibular and maxillary squamous cell proliferation was apparent in 31-week-old juveniles exposed to as low as 0.96 (xg ΣPCBs/g feed (9.2 pg TEQ/g). Juveniles in this treatment group had a liver concentration of 1.7 μg ΣPCBs/g wet weight (40 pg TEQ/g). Because inclusion of PCB-contaminated fish, which comprised approximately 1% of the diet, resulted in mandibular and maxillary squamous cell proliferation, it is possible that consumption of up to 30-fold that quantity of HR fish, as could be expected for wild mink, would result in more severe lesions characterized by loss of teeth, thus impacting survivability.
34 citations
TL;DR: Results indicated that inclusion of up to 30% carp in the diet had no effect on mink reproduction and kit survivability, and proliferation of maxillary and mandibular squamous epithelia could be induced in ranch mink exposed to environmentally-derived polychlorinated hydrocarbons in utero, during lactation, and throughout the growth period.
Abstract: Polychlorinated hydrocarbons, including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), are ubiquitous environmental contaminants that bioconcentrate in the food chain. Numerous studies have demonstrated mink (Mustela vison) to be one of the most sensitive species to this group of compounds. In recent studies, a lesion characterized by osteoinvasion of epithelial cells into the mandible and maxilla of young mink fed diets containing 3,3’,4,4’,5-pentachlorobiphenyl (PCB 126) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was observed. The objective of the present study was to determine if proliferation of maxillary and mandibular squamous epithelia could be induced in ranch mink exposed to environmentally-derived polychlorinated hydrocarbons (PCBs, PCDDs, and PCDFs) in utero, during lactation, and throughout the growth period. Adult female mink were fed diets containing 0, 10, 20, or 30% carp (Cyprinus carpio) collected from the Saginaw River, Bay City, Michigan, USA, that provided 0.03, 0.83, 1.1, and 1.7 mg total PCBs (tPCBs)/kg feed and 2.5, 28, 47, and 73 ng TCDD toxic equivalents (TEQs)/kg feed, respectively, three weeks prior to breeding through weaning of the resulting offspring. Mink kits were maintained on their respective diets for up to 27 weeks of age. At 6 and 27 weeks of age, six to eight mink in each treatment group were necropsied and their jaws examined for evidence of maxillary and mandibular squamous epithelial proliferation. Results indicated that inclusion of up to 30% carp in the diet (1.7 mg tPCBs/kg feed, 73 ng TEQs/kg feed) had no effect on mink reproduction and kit survivability. However, maxillary and mandibular squamous epithelial proliferation was evident in four of the seven 27-week-old juveniles in the 20% carp group (1.1 mg tPCBs/kg feed, 47 ng TEQs/kg feed) and six of the eight juveniles in the 30% carp group (1.7 mg tPCBs/kg feed group, 73 ng TEQs/kg feed). Hepatic concentrations of tPCBs and TEQs increased in both the 6-week-old kits and the 27-week-old juveniles as the percentage of dietary carp increased. The livers of 6-week-old kits were also assessed for the presence of polybrominated diphenyl ethers, which increased as the percentage of Saginaw River carp in the diet increased.
TL;DR: It is suggested that the expression of both SR-BI isoforms is required for the maintenance of low EC levels and that the predominance of only one isoform is associated with the accumulation of EC but not with apoptosis in the tubules.
TL;DR: The distribution patterns of 3H radioactivity across the FAs isolated from seal blubber and mink subcutaneous adipose tissue were comparable, indicating that mink are a good model for the investigation of lipid metabolism in marine carnivores.
Abstract: Cetoleic acid (22:1n‐11) is a good indicator of diet in marine predators and has proven to be an important fatty acid (FA) when using adipose tissue FA composition to study diet in marine mammals and seabirds. Feeding studies have shown that 22:1 isomers are predictably underrepresented in adipose tissue relative to diet, implying that metabolism within the predator strongly influences the relationship between the level of these FAs in diet and adipose tissue. Fully understanding such metabolic processes for individual FAs is important for the quantitative estimation of predator diets. We employed a dual‐label radioisotope tracer technique to investigate the potential modification of 22:1n‐11 and its recovery in the blubber of gray seals (Halichoerus grypus) and in the adipose tissue and liver of mink (Mustela vison), a smaller model carnivore also accustomed to fish‐based diets. In both seals and mink, 3H radioactivity was found in the chain‐shortened products of 22:1n‐11, with 18:1 being the do...
TL;DR: It is demonstrated that PGE2 plays an important role in regulating uterine and thus placental vascular development, acting through its receptors EP2 and EP4, provoking protein kinase A activation of AP2 and Sp1 as well as acetylation of histone H3 to transactivate the VEGF promoter.
TL;DR: An individual-based cellular lattice model based on a real landscape (Denmark) shows that the degree of adaptation within the free-ranging mink population is likely to vary spatially, with lower adaptation in areas where farm mink density is highest (due to the greater number of escaping mink).
Abstract: In this paper, we present an individual-based cellular lattice model, which is based on a real landscape (Denmark). The model predicts the distribution of free-ranging mink from data collated on the geographic locations of fur farms, the number of breeding mink kept per farm, and a range of parameters regarding escape, reproduction, mortality, and dispersal. When evolution was incorporated in the model, the results showed that the degree of adaptation within the free-ranging mink population is likely to vary spatially, with lower adaptation in areas where farm mink density is highest (due to the greater number of escaping mink). We used the model to explore the potential consequences of closing mink farms, or limiting escapes from them, on the evolutionary ecology of the free-ranging population and found that depending upon the paramaterisation of the evolutionary processes, several different outcomes are possible. Closing mink farms may result in a crash of the free-ranging population, or alternatively it may result in the establishment of a better-adapted, truly feral population that may ultimately outnumber the population that was present before farm closures. The main purpose of this paper is to raise awareness of the potential importance of evolutionary processes for the naturalisation of mink in Denmark, and to highlight the need for further work. Future field studies should be targeted to reduce the uncertainty in key parameters, allowing the development of an improved version of this model that can be used to generate management recommendations. More generally, we believe that further work linking evolutionary and population biology is required particularly in an applied context. There are likely to be many further scenarios where evolutionary processes may hold the key to understanding both population and community dynamics.
TL;DR: It is demonstrated that environmentally relevant exposures to DE-71 did not affect key parameters of the cholinergic neurotransmitter system in the brain of ranch mink.
TL;DR: Pancreatic lesions associated with hyperlipoproteinaemia start in exocrine cells, and are most probably the result of a metabolic disturbance, possibly a toxic effect of an excess of free fatty acids.
TL;DR: Current mink liver PCB concentrations are within the range associated with reproductive impairment, as determined from captive mink studies, in 11.7% of all animals collected from the Lakes Erie and St. Clair basin overall, but in almost 40% of individuals from western Lake Erie.
Abstract: Mink (Mustela vison) carcasses were collected from local commercial trappers from fall 1998 to spring 2003 from tributaries and marshes within 4.8 km from the shores of Lakes Erie and St. Clair, including the Wheatley Harbour and St. Clair River Areas of Concern (AOCs), as well as from inland sites (8 to 40 km from shore). Liver concentrations, on a lipid weight basis, of chlorinated hydrocarbons were measured and compared among sites and to tissue concentrations of mink from two previous collections from similar sites over the past 25 years. Mink from the western Lake Erie sites, which included the Wheatley Harbour AOC, had significantly higher concentrations of sum PCBs and PCB Aroclors than those from the St. Clair corridor or inland sites, with concentrations from the rest of Lake Erie being intermediate. Dieldrin concentrations were also significantly higher in western Lake Erie than many other sites, and those of oxychlordane and mirex also tended to be higher (0.05 < p < 0.1). There were no differences in contaminant concentrations between the St. Clair River AOC and the downstream non-AOC Lake St. Clair site, with the exception of slightly higher levels of octachlorostyrene (OCS). Concentrations of PCBs and other chlorinated hydrocarbons in mink showed a general decrease over the past two decades. In contrast, PCBs and some organochlorine pesticides tended to increase, significantly so with oxychlordane, in western Lake Erie mink over the same time period. DDE declined at all sites. Currently, mink liver PCB concentrations are within the range associated with reproductive impairment, as determined from captive mink studies, in 11.7% of all animals collected from the Lakes Erie and St. Clair basin overall, but in almost 40% of individuals from western Lake Erie.
TL;DR: No overt thyroid toxicity was apparent as thyroid weight, activity, and structure in kits and juveniles of both sexes were similar among diet groups, and plasma retinol and total ester concentrations in mink fed the 30% carp diet relative to controls.
TL;DR: In this article, the value of swimming water for farmed mink was investigated by measuring anticipatory and stereotypical behaviour in subjects raised and housed in the presence and absence of swimming waters.
TL;DR: Baiting traps with scent gland extracts was significantly more effective than baiting with fish and showed that the scent lure was equally attractive to both male and female mink.
Abstract: Introduced invasive American mink are currently posing a threat to endangered bird species on the Western Isles, an archipelago off the west coast of Scotland. As part of a 5‐year eradication campaign established in 2001, we conducted a small‐scale experiment in 2002 and 2003 on six offshore islands, ranging from 9 to 31 ha. Over 810 trap‐nights, 82 live traps were alternately baited with mink scent gland extracts or with traditional fish baits. Baiting traps with scent gland extracts was significantly more effective than baiting with fish. In 2003 a large‐scale field trial was carried out over a 900 km2 section of the Western Isles, using either commercially made scent gland lure or fish to bait complete trap‐lines of 20–35 traps. Trapping with 2154 live traps over 22 525 trap‐nights confirmed the results of the small‐scale experiment, and also showed that the scent lure was equally attractive to both male and female mink. The technique is recommended as a means of improving the efficiency of in...
Journal Article•
TL;DR: Neither sign surveys nor trapping are reliable methods for estimating relative abundances because both are subjected to strong biases, which could severely affect management projects that consider only main streams and projects aimed at extracting American minks need to consider those individuals that never trigger traps.
Abstract: A b s t r a c t. We compared different methods of monitoring an American mink, Mustela vison, population in an European mink, Mustela lutreola, area. The study was carried out in the Butron basin, northern Spain. We compared sign surveys and trapping in the same non-continuous 500 m sections of river. We also radio-tagged 10 minks to evaluate the efficiency of the two methods. There was no significant association between the presence of tracks and trapping success. We noticed the presence of minks in sections where none was captured and vice versa. Furthermore, by monitoring the radio-collared minks, we found inter-sexual differences in spatial use that produced differences in the success of the trapping and sign surveys, with males using the main streams and females selecting little streams where tracks were difficult to survey. Moreover, we detected tracks in the sand of 17 minks that actively avoided the traps. Hence, 1) neither sign surveys nor trapping are reliable methods for estimating relative abundances because both are subjected to strong biases. 2) the spatial use of habitat by minks could severely affect management projects that consider only main streams and 3) projects aimed at extracting American minks need to consider those individuals that never trigger traps, females living in very small streams and the floating population living in other habitats.
TL;DR: A method is described for the identification of European mink hair by light microscopy, and its differentiation, on the basis of cuticular and medullary patterns of guard hairs, from hairs of similar mustelids, the introduced American mink Mustela vison and the European polecat Mustela putorius.
Abstract: The European mink Mustela lutreola is a threatened species that is being monitored throughout its range, and innocuous methods of detection are needed as an alternative to live trapping, which may result in fatalities. A method is described for the identification of European mink hair by light microscopy, and its differentiation, on the basis of cuticular and medullary patterns of guard hairs, from hairs of similar mustelids, the introduced American mink Mustela vison and the European polecat Mustela putorius. When used in conjunction with hair trapping of living animals, this could prove to be the ideal way of conducting monitoring programmes on the European mink.
TL;DR: A free-ranging mink (Mustela vison), estimated to be 3 mo old, was found on the campus of Michigan State University, East Lansing, Michigan; it exhibited clinical signs of left hind limb lameness, ataxia, head tremors, and bilateral blindness, the first report of clinical toxoplasmosis in a free- ranging mink.
Abstract: A free-ranging mink (Mustela vison), estimated to be 3 mo old, was found on the campus of Michigan State University, East Lansing, Michigan; it exhibited clinical signs of left hind limb lameness, ataxia, head tremors, and bilateral blindness. Histologically, the animal had a mild, nonsuppurative meningoencephalitis and severe chorioretinitis with intralesional bradyzoites and tachyzoites. Protozoal organisms were identified as Toxoplasma gondii based on histology, immunohistochemistry, and polymerase chain reaction. To the authors' knowledge, this is the first report of clinical toxoplasmosis in a free-ranging mink.
TL;DR: The results show that the validated Rb+ efflux assay can be used for screening of KCNQ1/KCNE1 openers that potentially treat LQTS in both inherited and acquired forms and for evaluation of possible long-QT liability during cardiac selectivity of new chemical entities.
Abstract: The slow delayed rectifier K+ current, Iks, encoded by KCNQ1 (KvLQT1)/KCNE1 (mink) genes, contributes to cardiac action potential repolarization and determines the heartbeat rate. Mutations in either KCNQ1 or KCNE1 that reduce Iks cause long-QT syndrome (LQTS), a disorder of ventricular repolarization that results in cardiac arrhythmia and sudden death. A well-recognized potential treatment for LQTS caused by reduction of Iks is to enhance functional activation of cardiac KCNQ1/KCNE1 channels. In the present study, we generated a stable Chinese hamster ovary cell line that expresses KCNQ1/KCNE1 channels confirmed by electrophysiology. Using a pharmacological tool compound R-L3 (L-364,373 [(3-R)-1,3-dihydro-5-(2-fluorophenyl)-3-(1H-indol- 3-ylmethyl)-1-methyl-2H-1,4-benzodiazepin-2-one]), which activates KCNQ1/mink channels, we then developed and validated a non-radioactive rubidium (Rb+) efflux assay that directly measures the functional activity of KCNQ1/KCNE1 channels by atomic absorption spectroscopy. ...
TL;DR: The experiment showed that BPM can account for 40% of dietary protein in growing-furring mink without negative effects on N metabolism, body weight gain or fur quality.
Abstract: A bacterial protein meal (BPM), containing 70% crude protein and produced on natural gas, was evaluated versus fish meal as protein source for mink in the growing-furring period (June 29 November 26). BPM, rich in nucleic acids, accounted for 0 (control), 20 and 40% of dietary crude protein corresponding to 0, 4 and 8% of the wet diets, respectively. Each diet was given to 48 animals, 24 males and 24 females. The inclusion of BPM tended to reduce feed intake and body weight gain during the first half of the experimental period, but this was compensated for during the last part of the experiment, except for males on the 8% BPM diet. Balance experiments carried out with 18 and 28 weeks old males, revealed similar digestibility of main nutrients except for fat that were reduced with BPM inclusion. N-retentions were similar for the dietary groups. Daily excretion of urine was lower with the 8% BPM diet than with the other diets. Excretion of urinary purine derivatives (allantoin, xanthine), decreased or was not consistently affected (hypoxanthine, uric acid) by the dietary level of BPM, indicating that nucleic acids from BPM were utilized in vivo. The skin characteristics and fur quality were not affected by diet, except for shorter hair length with inclusion of BPM. In conclusion, the experiment showed that BPM can account for 40% of dietary protein in growing-furring mink without negative effects on N metabolism, body weight gain or fur quality.
TL;DR: SARS-CoV-like viruses isolated from palm civets appeared to be under strong selective pressure and are genetically most similar to viruses infecting humans early in the outbreak, and may have generated strains that could be more easily transmitted to humans.
Abstract: In 2002–2003, there was an outbreak of severe acute respiratory syndrome (SARS) in Guangdong Province, China. This outbreak subsequently affected 29 countries and resulted in 8,096 cases of SARS, of which 774 were fatal. The causative agent was determined to be a previously unrecognized CoV, which became known as SARS-CoV. The SARS-CoV outbreak likely resulted from zoonotic transmission. Although SARSCoV was isolated from several species, the natural reservoir of its progenitor remains to be discovered. Of the animals examined to date, SARS-CoV was most frequently isolated from Himalayan palm civets, which are sold in live animal markets in Guangdong and in other regions of Southeast Asia. The role palm civets played in the SARS outbreak is unclear. However, SARS-CoV-like viruses isolated from palm civets appeared to be under strong selective pressure and are genetically most similar to viruses infecting humans early in the outbreak. The selective pressure of replication in palm civet may have generated strains that could be more easily transmitted to humans. Palm civets are carnivores in the suborder Fissipedia. Other Fissipedia include raccoon dog, dog, cat, raccoon, skunk, ferret (Mustela putorius), and mink (Mustela vison). SARS-CoV-like virus was also detected in a raccoon dog in a live animal market. Furthermore, Fissipedia
TL;DR: Based on these findings, the use of embryo transfer for a conservation programme for the European mink was evaluated and both male and female offspring were lighter at birth in the embryo transfer group compared with naturally born controls, but there was no difference at 3 months of age.
Abstract: The European mink is an endangered Mustelidae species and thus requires effective conservation measures, although little is known about reproduction in this species. In particular, preimplantation development has not been studied and, therefore, embryonic development and the growth of embryos was documented in the present study for European mink using light and fluorescent microscopy. Embryos develop in the oviducts and then migrate into the uterus on Day 6 post coitum (p.c.) at the morula stage. Embryos expanded as blastocysts from Day 7 until implantation on Day 12 p.c. Based on these findings, the use of embryo transfer for a conservation programme for the European mink was evaluated. Embryos were flushed from European mink resource females and transferred into the uterine horns of recipient hybrid females (honoriks and nohoriks). These hybrids were obtained by mating European polecat males with European mink females and vice versa. A total of 40 embryos was transferred and 20 live kits were born. The rates of pre- and postnatal survival were 50% and 70%, respectively. Both male and female offspring were lighter at birth in the embryo transfer group compared with naturally born controls, but there was no difference at 3 months of age.
TL;DR: It is concluded that the mink differs from previously studied homeotherms in thermoregulatory and behavioral responses to fasting probably due to its high energy requirements and predatory success.
Abstract: The aim of this study was to investigate the thermoregulatory adaptations to fasting in a medium-sized mustelid with a high metabolic rate and energetic requirements. Sixteen farm-bred female American minks, Mustela vison, were divided into a fed control group and an experimental group fasted for 5 days. The deep body temperature (Tb) of the minks was registered at 10 min intervals with intraabdominal thermosensitive loggers and the locomotor activity was videotaped continuously for 5 days during the fasting procedure. The Tb of the fasted animals increased during the first day of fasting and decreased during the second day. After 3–4 days of fasting, the levels of physical activity and Tb of the fasted minks increased above the levels of the fed animals. Significant increases in these parameters were observed at the beginning of the working day on the farm, during the feeding of the fed animals and around midnight. It is concluded that the mink differs from previously studied homeotherms in thermoregulatory and behavioral responses to fasting probably due to its high energy requirements and predatory success. J. Exp. Zool. 305A:1–10, 2006. © 2006 Wiley-Liss, Inc.
TL;DR: The results of this study suggest that minks are sensitive to perinatal phytoestrogen exposure.