Project description:Spotted seals (Phoca largha) is a critically endangered pinniped in China and South Korea. Captive in artificially controlled environment is a conventional method to protect and maintain the population of this species. However, little is known about the physiological differences between the wild and captive P. largha. In order to draw the preliminary protein expression profile in the P. largha, blood from the wild and captive pups were subjected to a label-free comparative proteomic analysis. According to the results, 972 proteins were identified, which performed functions related to various metabolic, immune and cellular processes. Among these identified proteins, the expression level of 51 proteins significantly changed between the wild and captive P. large pups. These differentially expressed proteins were enriched in a wide range of cellular functions, including cytoskeleton, phagocytosis. proteolysis, gene expression regulation and carbohydrate metabolism. The activities of phagocytosis and its related ubiquitin mediated proteolysis were significantly higher in the blood of wild P. largha pups than in captive individuals. In addition, a key protein associated with the differences in the wild and captive P. largha pups, heat shock protein 90-beta, were determined due to the most interactions of it with various differentially expressed proteins. Moreover, the wild P. largha pups could be more nutritionally stressed and have more powerful immune capacity. Our study provides the first data on the preliminary protein composition and gives useful information for the physiological characteristics research in this species.
Project description:Captive breeding is one of the most effective ways of ensuring the conservation of several endangered species. However, only a few studies have explored the effects of living in captivity on animals at the molecular level. In the present study, the isobaric tags for relative and absolute quantification (iTRAQ) approach was applied to compare protein expression in the blood of endangered spotted seal pups (Phoca largha) inhabiting different environments. We identified 519 proteins from 2,628 peptides. The expression of 158 proteins significantly differed between seals in temporary captivity and those in the wild. In addition, 140 proteins were differentially expressed between seals in temporary captivity and those in long-term captivity, and 235 proteins were differentially expressed between the wild and long-term captive groups (p < 0.05). In seal pups in the wild, proteins associated with maintaining cell stability and integrity of cardiomyocytes, protecting the heart, and preventing anaemia were upregulated, reflecting the high stress and energetic costs of moving and foraging. In addition, significant differences were detected in immune-related proteins among the three groups. The results of this study expand our understanding of protein expression profiles in spotted seals and provide data to support future conservation of this species.
Project description:Tidewater glacial fjords in Alaska provide habitat for some of the largest aggregations of harbor seals (Phoca vitulina), with calved ice serving as platforms for birthing and nursing pups, molting, and resting. These fjords have also been popular destinations for tour ships for more than a century, with dramatic increases in vessel traffic since the 1980s. Seals on ice are known to flush into the water when approached by tour ships, but estimating the exposure to disturbance across populations is difficult. Using aerial transect sampling while simultaneously tracking vessel movements, we estimated the spatial overlap between seals on ice and cruise ships in Disenchantment Bay, Alaska, USA. By integrating previously estimated rates of disturbance as a function of distance with an 'intensity surface' modeled spatially from seal locations in the surveys, we calculated probabilities of seals flushing during three separate ship visits. By combining our estimate of seals flushed with a modeled estimate of the total fjord population, we predict that up to 14% of the seals (up to 11% of pups) hauled out would have flushed into the water, depending on the route taken by ships relative to seal aggregations. Such high potential for broad-scale disturbance by single vessels (when up to 4 ships visit per day) was unexpected and underscores the need to 1) better understand long-term effects of disturbance; 2) regularly monitor populations exposed to high vessel traffic; and 3) develop conservation measures to reduce seal-ship overlap.