9 research outputs found
Diseases of red deer introduced to Patagonia and implications for native ungulates
The red deer (Cervus elaphus) invasion in Patagonia has been continuing for nearly a century, with occurrence in all habitats between 34-55°S. Their distribution, movement patterns and locally high densities raise concerns over their potential epidemiological role in maintaining disease reservoirs or transmitting diseases like foot-and-mouth disease or tuberculosis, with potential severe health and economical impact at the interface of humans, livestock or native wildlife. Among adult females collected by rifle and radiocollared deer that died naturally, no ectoparasites were found (n=73). Fasciola hepatica was encountered in three surveys at prevalences ranging from 9 to 50% (n=108). Taenia ovis krabbei was identified, and Cysticerus tenuicollis was found at a prevalence of 8% (n=12). Ostertagia sp., Bunostomum sp., and Dictyocaulus sp. had a prevalence of 75%, 25% and 13% (n=9), respectively. Several gastrointestinal parasites reported at low prevalence in endangered Patagonian huemul (Hippocamelus bisulcus), are common in livestock and considered commensals in domestic ruminants. Sympatry of huemul with livestock is commonplace, whereas with red deer it occurs in 100 years in Argentina, both red deer and livestock play epidemiological roles for shared diseases. Research, conservation and management efforts should be directed towards livestock herd health programs or restriction of free livestock movements, particularly if diseases are shown to have impact on recruitment of endangered natives. Livestock are routinely researched and inspected at slaughter and thus provide a proxy for diseases afflicting co-existing ungulates.Testing for antibodies to foot-and-mouth disease viral antigen was negative (n=41). A tentative diagnosis of mycobacterial infection was based on typical visceral lesions. Antler damage occurred on 73% of shed antlers, with 36% having major breaks of tines and main beams, possibly indicating mineral imbalances. One male had both antlers, including pedicles with portions of frontal, parietal and occipital bones broken off the skull, causing his death. The prevalence of 0.9% of campylognathia (n=776) indicates that the disease unlikely is inheritable, because the founding stock of 20 animals would have had a prevalence of at least 5%. Among deer, handedness of scoliosis related significantly to the hemisphere where specimens originated (p <0.001, n=131). Coriolis forces are known to affect early stages of development such as the innervation pattern of the mammalian vestibular system, or the plane of bilateral symmetry. It is therefore conceivable that the networks processing these environmental cues, or the mechanisms responsible for compensation, are malfunctioning and thus result in a preponderance of facial scoliosis in accordance to the earth´s rotation.Fil: Fluck, Werner Thomas. Universidad de Basilea; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Smith Flueck, Jm. Universidad Atlantida Argentina; Argentin
Delayed Recovery of Skeletal Muscle Mass following Hindlimb Immobilization in mTOR Heterozygous Mice
The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/−) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR+/− mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR+/− mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR+/− mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA) during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth
Identification and Genome-Wide Prediction of DNA Binding Specificities for the ApiAP2 Family of Regulators from the Malaria Parasite
The molecular mechanisms underlying transcriptional regulation in apicomplexan parasites remain poorly understood. Recently, the Apicomplexan AP2 (ApiAP2) family of DNA binding proteins was identified as a major class of transcriptional regulators that are found across all Apicomplexa. To gain insight into the regulatory role of these proteins in the malaria parasite, we have comprehensively surveyed the DNA-binding specificities of all 27 members of the ApiAP2 protein family from Plasmodium falciparum revealing unique binding preferences for the majority of these DNA binding proteins. In addition to high affinity primary motif interactions, we also observe interactions with secondary motifs. The ability of a number of ApiAP2 proteins to bind multiple, distinct motifs significantly increases the potential complexity of the transcriptional regulatory networks governed by the ApiAP2 family. Using these newly identified sequence motifs, we infer the trans-factors associated with previously reported plasmodial cis-elements and provide evidence that ApiAP2 proteins modulate key regulatory decisions at all stages of parasite development. Our results offer a detailed view of ApiAP2 DNA binding specificity and take the first step toward inferring comprehensive gene regulatory networks for P. falciparum
A view on the role of epigenetics in the biology of malaria parasites
Cells and unicellular organisms are similar to their progenitors because information is transmitted from one generation to the next. The information is mainly transmitted in the primary sequence of the genome (genetic information), but there are heritable traits that are transmitted by other mechanisms. Epigenetics studies these alternative modes of inheritance. According to classic definitions, epigenetics refers to heritable differences between cells or organisms that occur without changes in DNA sequence, and do not depend on different external conditions