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The work was funded from core support given to the Sea Mammal Research Unit, Scottish Oceans Institute from the Natural Environmental Research Council (United Kingdom). Mammalian mothers usually provide their offspring with large quantities of immunoglobulins (antibodies) for circulation in blood, either trans-placentally before birth, via colostrum briefly thereafter, or, less commonly, from milk. Neonates of true, phocid seals, however, are peculiarly impoverished in serum immunoglobulins, the levels of which slowly increase but do not reach adult levels by the time of weaning. We investigated whether grey seal (Halichoerus grypus) neonates compensate through an elevation or rapid maturation in levels of serum innate immune factors, namely acute phase and complement proteins. Instead, their sera contained remarkably low levels of acute phase proteins (including C-reactive protein, haptoglobin, hemopexin, ceruloplasmin, orosomucoid), compared to their mothers, that barely increased to adult levels by weaning. For complement, there was a strong demarcation between the early activation and amplification cascade components (present at normal adult levels in pups) and the late lytic membrane attack complex and regulatory proteins (consistently at low relative levels). Phocid neonates therefore differ dramatically from land Carnivorans, such as dogs and cats, in early life immune protection. That neonatal phocids survive this apparent vulnerability to infections between birth and weaning prompts questions as to what other mechanisms protect them, and the adaptive value of their seeming vulnerability. Publisher PDF

Funding: The work was funded from core support given to the Sea Mammal Research Unit, Scottish Oceans Institute, from the Natural Environmental Research Council (United Kingdom). True, phocid seals have the shortest known lactations relative to body mass, during which mass transfer of adipose stores from mother to offspring occurs at an unrivalled rate and extent. The mothers of most species of seal fast until weaning whilst their pups gorge on the most fat-rich milks known. This results in a dramatic reduction in maternal blubber mass while pups may triple their body weights before weaning. Mothers mobilise their blubber fat, transport it via blood to their mammary glands and into milk, whilst pups transfer fat in the opposite direction, from their intestines, via blood, to their blubber. Using proteomic analysis of mother and pup sera from Atlantic grey seals, we find that this mirror image flux of lipids between mothers and pups is reflected in an almost inverse relationship in the proteins in their blood specialised to transport fats, lipids, and fat-soluble vitamins. For instance, apolipoproteins ApoB-48/100, ApoA-II and ApoA-IV, which are structural components of the main lipid carrier complexes such as chylomicrons and HDL particles, occur at much higher levels in pups than mothers. Meanwhile, carriers of fat-soluble vitamins such as retinol- and vitamin D-binding proteins are lower in pups and gradually build towards weaning. In contrast, sex hormone-binding globulin occurs at remarkably high relative concentrations in pups. There are therefore dramatic differences between, and an unrealised complexity in, the balance of proteins involved in the rapid transfer of fats and other lipids from mother to pups in preparing their offspring for their post-weaning fasts on land and eventual survival at sea before they can feed again. Publisher PDF

Canine babesiosis is an important worldwide tick- borne disease caused by the intra-erythrocyte protozoal parasites Babesia canis or Babesia gibsoni (Beck et al., 2009). Although the disease process primarily affects erythrocytes, it may also have multisystemic consequences (Barić Rafaj et al., 2013). The main complications are the development of an excessive inflammatory response called ”systemic inflammatory response syndrome” or SIRS (Bone et al., 1992) and also a multiple organ dysfunction syndrome or MODS (Jacobson and Clark, 1994). Specific metabolites are being discovered as biomarkers to improve disease diagnosis, prognosis, and treatment outcomes. The emergence of innovative, post-genomic technologies, has led to the development of strategies aimed at identifying specific and sensitive biomarkers among thousands of molecules present in biological fluids and tissues (Moore et al., 2007). Nowadays, according to its great potential for biomarkers evaluation, metabolomics is one of the most frequently applied approaches in the field of systems biology (Robinson et al., 2014). Blood and urine contains a multitude of unstudied and unknown biomarkers that may reflect physiological and pathological states of tissues and organs. Particularly low-molecular-weight region of metabolome from blood samples is an important source of diagnostic biomarkers. The goal was to examine the difference of serum metabolome between dogs naturally infected with Babesia canis (B. canis) and healthy dogs using liquid chromatography coupled to mass spectrometry (LC-MS).Serum was collected from 12 dogs naturally infected with B. canis and 12 healthy dogs. Briefly, 25 μL serum aliquots were prepared, and 1000 μL of 1:3:1 chloroform:methanol:water was added to precipitate the proteins. The samples were allowed to cool on ice for 30 minutes before centrifugation to pellet the proteins. The Eppendorf tubes vortexed on 4˚C for 5 minutes, and then centrifuge for 3 minutes at 13.000 g at 4˚C. The supernatant (200 μL) was transferred to a screw-top vial and stored at 80˚C until liquid chromatography-mass spectrometry (LC-MS) analysis. Samples were analysed on an Orbitrap Q-Exactive mass spectrometer (Thermo Fisher Scientific) operating in alternating positive and negative negative modes with mass resolution 70.000 at m/z range 70 – 1050. Analyses were performed using Polyomics integrated Metabolomics Pipeline (PiMP) program specifically designed for metabolomics.The metabolomics analysis resulted in the annotation of 1802 peaks, 158 of which showed statistically significant differences (p < 0.05) between dogs with B. canis infection and healthy control. The peaks represent metabolites in positive and negative modes. 22 identified metabolites were significantly changed. The most significant metabolites are Inosine, Hypoxanthine, Choline phosphate, Hypoxanthine, L-Kynurenine, and L- Cystine. Biological functions of differently abundant metabolites indicate the involvement of various pathways in canine babesiosis including aminobenzoate degradation, benzoate degradation, bile secretion, calcium signalling pathway, D- glutamine and D-glutamate metabolism, dioxin degradation, phenylalanine metabolism, and purine metabolism.The study confirmed that host pathogen interactions (Dog – B. canis) can be studied by metabolomics to assess chemical changes in the host, respectively that the differences in serum metabolome between dogs with B. canis infection and healthy dogs can be detected with LC-MS method. The non-targeted LC-MS metabolomic’s approach profiled the metabolic change in serum from B. canis-infected dogs.

True seals have the shortest lactation periods of any group of placental mammal. Most are capital breeders that undergo short, intense lactations, during which they fast while transferring substantial proportions of their body reserves to their pups, which they then abruptly wean. Milk was collected from Atlantic grey seals (Halichoerus grypus) periodically from birth until near weaning. Milk protein profiles matured within 24 hours or less, indicating the most rapid transition from colostrum to mature phase lactation yet observed. There was an unexpected persistence of immunoglobulin G almost until weaning, potentially indicating prolonged trans-intestinal transfer of IgG. Among components of innate immune protection were found fucosyllactose and siallylactose that are thought to impede colonisation by pathogens and encourage an appropriate milk-digestive and protective gut microbiome. These oligosaccharides decreased from early lactation to almost undetectable levels by weaning. Taurine levels were initially high, then fell, possibly indicative of taurine dependency in seals, and progressive depletion of maternal reserves. Metabolites that signal changes in the mother’s metabolism of fats, such as nicotinamide and derivatives, rose from virtual absence, and acetylcarnitines fell. It is therefore possible that indicators of maternal metabolic strain exist that signal the imminence of weaning. Publisher PDF