Integrated proteomics and metabolomics reveal the variations in the physiological state of spotted seal (Phoca largha) pups following artificial rescue.

Spotted seals (Phoca largha) are a critically endangered pinniped in China. Artificial rescue of newborn pups is a conventional method to enhance their survival and maintain the population. However, little is known about the variations in the physiological state of spotted seal pups following artificial rescue. Here, an integrated proteomics and metabolomics study was performed on spotted seal pups by using whole blood samples to characterize the molecular response to artificial rescue. The proteome was characterized as having 1165 proteins that were predominantly associated with the metabolic pathways, and the complement and coagulation cascades. Remarkable variation was found in spotted seal pup blood following artificial rescue, whereby the levels of 193 proteins and 32 metabolites significantly varied in some metabolic pathways, including glycosylphosphatidylinositol-anchor biosynthesis, focal adhesion, cardiac muscle contraction, and fatty acid beta-oxidation. After rescue, spotted seal pups had a higher risk to mild hemolytic disorder due to the energy metabolism in the red blood cells was possibly suppressed. Moreover, spotted seal pups after rescue could have stronger anaerobic exercise abilities, while their capacity for long-term high-intensity exercise was weaker.

Age-associated variation in the gut microbiota of chinstrap penguins (Pygoscelis antarctica) reveals differences in food metabolism.

Age is known to affect the gut microbiota in various animals; however, this relationship is poorly understood in seabirds. We investigated the temporal succession of gut microbiota in captive chinstrap penguins of different ages using high-throughput sequencing. The gut microbiota exhibited a significant age succession pattern, reaching maturity in adults and then declining with increasing age. Only 15 amplicon sequence variants were shared among the gut microbiota in chinstrap penguins at all studied ages, and these contributed to most of the age-related variations in total gut microbiota. Co-occurrence networks found that these key bacteria belonged to the genera Acinetobacter, Clostridium sensu stricto, and Fusobacterium, and more species interactions were found within the same taxonomy. Functional prediction indicated that most of the metabolic functions were more abundant in the gut microbiota in adult chinstrap penguins, except for carbohydrate metabolism, which was significantly more abundant in older individuals.

Identification of the complete mitochondrial genome of the king penguin Aptenodytes patagonicus (Sphenisciformes: Spheniscidae: Aptenodytes).

The complete mitochondrial genome of the king penguin Aptenodytes patagonicus was firstly determined. The mitogenome is 17,477 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a control region. The total nucleotide composition is 31.0% A, 22.2% T, 33.1% C, and 13.8% G, with a total A + T content of 53.2%. The phylogenetic analysis demonstrates a close relationship between A. patagonicus and A. forsteri. These results provide fundamental information for further phylogeny and genetic studies on Aptenodytes genus.