106 research outputs found
The Proteomic Response of Northern Elephant Seal (\u3ci\u3eMirounga angustirostris\u3c/i\u3e) Pups to Physiological Stress during Development
Background: Northern elephant seals transition from terrestrial nursing pups to pelagic foraging juveniles in a short period of just 8-12 weeks. During the post-weaning period, pups rely solely on the energy reserves gained during nursing for their caloric demands and water supply. The prolonged absence of food after weaning is the first of many fasts for which the seals have evolved adaptations such as decreased urine production and increased blubber reserves. The stressors experienced from learning to dive for the first time are also stressors that they will experience frequently as an adult and for which they have evolved adaptations. The purpose of this study was to understand the tissue-specific molecular fasting- and diving- induced adaptive responses of pups during this critical transition.
Methods: To investigate these adaptive responses to fasting and diving, we collected skeletal muscle and (inner and outer) adipose tissue from early-fasting (\u3c 1 week post-weaning) and late-fasting (8 weeks post-weaning) pups. We analyzed the samples with mass-spectrometry-based proteomics using two-dimensional gel electrophoresis. Proteomics is an invaluable tool for analyzing marine mammal physiology, as it provides a large, unbiased data set of proteins that offer a comprehensive set of mechanisms involved with the cellular processes being studied. Proteomics has only been used as analytical tool for marine mammal biology in two other studies, and it can be used as a tool leading to the discovery of novel, unanticipated results.
Results and Discussion: Because muscles are utilized during locomotion, we expected the proteome of skeletal muscle to highlight important physiological changes as the pups learn to dive. Inner adipose is more metabolically active than outer adipose, so we anticipated it would show important changes in metabolism throughout their fast. Outer adipose was useful to detect changes in the proteome due to thermoregulation, as it experiences the most drastic change in temperature and pressure while the pups learn to dive. In all tissues, we found significant shifts in energy metabolism proteins that show a decrease in lipid metabolism and urine production, and an increase in alternative metabolic pathways, such as the pentose phosphate pathway, which produces precursors for nucleic acid synthesis. We also found increases in cytoskeletal proteins, skeletal muscle proteins, and oxygen-binding proteins that facilitate the development of diving ability in late-fasting pups. Lastly, changes in the abundance of oxidative stress related proteins showed increased use of antioxidant proteins to control the production of reactive oxygen species in late-fasting pups. This study provides insight into cellular and physiological responses in marine mammals during ontogeny and their adaptive capacity during a key transition from a terrestrial to aquatic lifestyle
Excitability scores of goats administered ascorbic acid and transported during hot-dry conditions
In this study, we investigated the effect of ascorbic acid (AA) administration on goat excitability due to transportation. Ten goats administered AA (p.o.) at 100 mg/kg of body weight before transportation served as the experimental group, and seven goats administered only 10ml/kg of sterile water (p.o.) served as controls. Excitability scores were recorded for each goat; when weighed, before, immediately after, and 3 h after 8 h of transportation. A score of one to four was allocated to each goat; higher scores represent greater excitability. Immediately after transportation, excitability scores decreased significantly, especially those of control goats (p < 0.001). At 3 h post-transportation, the excitability scores of animals in the experimental group were not significantly (p>0.05) different from their pre-transportation normal values, whereas those of control goats were significantly lower (p < 0.01). The correlation i.e. the relationship between excitability score values and percent excitability (percentage of goat with particular excitability score) for different excitability score group 3 h post-transportation was positive and highly significant (p < 0.001), in both experimental and control goats. Our results indicate that road transportation induces considerable stress (depression) in goats as evidenced by a lower excitability score post-transportation. Moreover, the administration of AA pre-transportation facilitated the transition from a state of depression to excitation. In conclusion, AA administration to animals prior to transportation may ameliorate the depression often encountered after road transportation
Molecular dissection of mRNA poly(A) tail length control in yeast
In eukaryotic cells, newly synthesized mRNAs acquire a poly(A) tail that plays several fundamental roles in export, translation and mRNA decay. In mammals, PABPN1 controls the processivity of polyadenylation and the length of poly(A) tails during de novo synthesis. This regulation is less well-detailed in yeast. We have recently demonstrated that Nab2p is necessary and sufficient for the regulation of polyadenylation and that the Pab1p/PAN complex may act at a later stage in mRNA metabolism. Here, we show that the presence of both Pab1p and Nab2p in reconstituted pre-mRNA 3′-end processing reactions has no stimulating nor inhibitory effect on poly(A) tail regulation. Importantly, the poly(A)-binding proteins are essential to protect the mature mRNA from being subjected to a second round of processing. We have determined which domains of Nab2p are important to control polyadenylation and found that the RGG-box work in conjunction with the two last essential CCCH-type zinc finger domains. Finally, we have tried to delineate the mechanism by which Nab2p performs its regulation function during polyadenylation: it likely forms a complex with poly(A) tails different from a simple linear deposit of proteins as it has been observed with Pab1p
An essential role for Clp1 in assembly of polyadenylation complex CF IA and Pol II transcription termination
Polyadenylation is a co-transcriptional process that modifies mRNA 3′-ends in eukaryotes. In yeast, CF IA and CPF constitute the core 3′-end maturation complex. CF IA comprises Rna14p, Rna15p, Pcf11p and Clp1p. CF IA interacts with the C-terminal domain of RNA Pol II largest subunit via Pcf11p which links pre-mRNA 3′-end processing to transcription termination. Here, we analysed the role of Clp1p in 3′ processing. Clp1p binds ATP and interacts in CF IA with Pcf11p only. Depletion of Clp1p abolishes transcription termination. Moreover, we found that association of mutations in the ATP-binding domain and in the distant Pcf11p-binding region impair 3′-end processing. Strikingly, these mutations prevent not only Clp1p-Pcf11p interaction but also association of Pcf11p with Rna14p-Rna15p. ChIP experiments showed that Rna15p cross-linking to the 3′-end of a protein-coding gene is perturbed by these mutations whereas Pcf11p is only partially affected. Our study reveals an essential role of Clp1p in CF IA organization. We postulate that Clp1p transmits conformational changes to RNA Pol II through Pcf11p to couple transcription termination and 3′-end processing. These rearrangements likely rely on the correct orientation of ATP within Clp1p
Transferring Results of Behavioral Research to Industry to Improve Animal Welfare on the Farm, Ranch and the Slaughter Plant
The article focuses on three results of the study: "(1)Communicate your results outside the research. Write articles in popular and industry magazines. Speak at producer meetings and develop websites that can be used to transfer research results into practice. (2) Choose places (e.g. farms or plants) that have managers who believe in your research, and be prepared to spend a lot of time with the first place that uses your findings. (3) to fail. (4) Do not allow your technology to get tied up in patent disputes.
Effects of Wolves on Elk and Cattle Behaviors: Implications for Livestock Production and Wolf Conservation
BACKGROUND: In many areas, livestock are grazed within wolf (Canis lupus) range. Predation and harassment of livestock by wolves creates conflict and is a significant challenge for wolf conservation. Wild prey, such as elk (Cervus elaphus), perform anti-predator behaviors. Artificial selection of cattle (Bos taurus) might have resulted in attenuation or absence of anti-predator responses, or in erratic and inconsistent responses. Regardless, such responses might have implications on stress and fitness. METHODOLOGY/PRINCIPAL FINDINGS: We compared elk and cattle anti-predator responses to wolves in southwest Alberta, Canada within home ranges and livestock pastures, respectively. We deployed satellite- and GPS-telemetry collars on wolves, elk, and cattle (n = 16, 10 and 78, respectively) and measured seven prey response variables during periods of wolf presence and absence (speed, path sinuosity, time spent head-up, distance to neighboring animals, terrain ruggedness, slope and distance to forest). During independent periods of wolf presence (n = 72), individual elk increased path sinuosity (Z = -2.720, P = 0.007) and used more rugged terrain (Z = -2.856, P = 0.004) and steeper slopes (Z = -3.065, P = 0.002). For cattle, individual as well as group behavioral analyses were feasible and these indicated increased path sinuosity (Z = -2.720, P = 0.007) and decreased distance to neighbors (Z = -2.551, P = 0.011). In addition, cattle groups showed a number of behavioral changes concomitant to wolf visits, with variable direction in changes. CONCLUSIONS/SIGNIFICANCE: Our results suggest both elk and cattle modify their behavior in relation to wolf presence, with potential energetic costs. Our study does not allow evaluating the efficacy of anti-predator behaviors, but indicates that artificial selection did not result in their absence in cattle. The costs of wolf predation on livestock are often compensated considering just the market value of the animal killed. However, society might consider refunding some additional costs (e.g., weight loss and reduced reproduction) that might be associated with the changes in cattle behaviors that we documented
Ganho de peso e características de carcaça de bovinos Nelore castrados ou não-castrados terminados em confinamento
- …