Efficient and cost-effective non-invasive population monitoring as a method to assess the genetic diversity of the last remaining population of Amur leopard (Panthera pardus orientalis) in the Russia Far East.

Small populations of the endangered species are more vulnerable to extinction and hence require periodic genetic monitoring to establish and revisit the conservation strategies. The Amur leopard is critically endangered with about 100 individuals in the wild. In this study, we developed a simple and cost-effective noninvasive genetic monitoring protocol for Amur leopards. Also, we investigated the impact of fecal sample's age, storage, and collection season on microsatellite genotyping success and data quality. We identified 89 leopard scats out of the 342 fecal samples collected from Land of the Leopard between 2014-2019. Microsatellite genotyping using 12 markers optimized in 3 multiplex PCR reactions reveals presence of at least 24 leopard individuals (18 males and 6 females). There was a significant difference in the success rate of genotyping depending on the time from feces deposition to collection (p = 0.014, Fisher's exact test), with better genotyping success for samples having <2 weeks of environmental exposure. Amur leopard genetic diversity was found low (Ho- 0.33, HE- 0.35, and NA- 2.57) with no visible population substructure and recent bottleneck signature. Although a historical bottleneck footprint was observed. Mitochondrial DNA diversity was also found low with two haplotypes differing by a point mutation reported in 1,769 bp of investigated sequence covering parts of cytochrome b gene (846 bp), NADH-5 gene (611 bp) and control region (312 bp). We recommend periodic genetic monitoring of wild Amur leopards following the proposed methodology to achieve cost effectiveness and efficiency.

Whole genome survey of big cats (Genus: Panthera) identifies novel microsatellites of utility in conservation genetic study.

Big cats (Genus: Panthera) are among the most threatened mammal groups of the world, owing to hunting, habitat loss, and illegal transnational trade. Conservation genetic studies and effective curbs on poaching are important for the conservation of these charismatic apex predators. A limited number of microsatellite markers exists for Panthera species and researchers often cross-amplify domestic cat microsatellites to study these species. We conducted data mining of seven Panthera genome sequences to discover microsatellites for conservation genetic studies of four threatened big cat species. A total of 32 polymorphic microsatellite loci were identified in silico and tested with 152 big cats, and were found polymorphic in most of the tested species. We propose a set of 12 novel microsatellite markers for use in conservation genetics and wildlife forensic investigations of big cat species. Cumulatively, these markers have a high discriminatory power of one in a million for unrelated individuals and one in a thousand for siblings. Similar PCR conditions of these markers increase the prospects of achieving efficient multiplex PCR assays. This study is a pioneering attempt to synthesise genome wide microsatellite markers for big cats.

CD11b Deficiency Exacerbates Methicillin-Resistant Staphylococcus aureus-Induced Sepsis by Upregulating Inflammatory Responses of Macrophages.

Macrophages are important for the first line of defense against microbial pathogens. Integrin CD11b, which is encoded by Itgam, is expressed on the surface of macrophages and has been implicated in adhesion, migration, and cell-mediated cytotoxicity. However, the functional impact of CD11b on the inflammatory responses of macrophages upon microbial infection remains unclear. Here, we show that CD11b deficiency resulted in increased susceptibility to sepsis induced by methicillin-resistant Staphylococcus aureus (MRSA) infection by enhancing the pro-inflammatory activities of macrophages. Upon infection with MRSA, the mortality of Itgam knockout mice was significantly higher than that of control mice, which is associated with increased production of TNF-α and IL-6. In response to MRSA, both bone marrow-derived macrophages and peritoneal macrophages lacking CD11b produced elevated amounts of pro-inflammatory cytokines and nitric oxide. Moreover, CD11b deficiency upregulated IL-4-induced expression of anti-inflammatory mediators such as IL-10 and arginase-1, and an immunomodulatory function of macrophages to restrain T cell activation. Biochemical and confocal microscopy data revealed that CD11b deficiency augmented the activation of NF-κB signaling and phosphorylation of Akt, which promotes the functional activation of macrophages with pro-inflammatory and immunoregulatory phenotypes, respectively. Overall, our experimental evidence suggests that CD11b is a critical modulator of macrophages in response to microbial infection.

mTOR kinase leads to PTEN-loss-induced cellular senescence by phosphorylating p53.

Loss of PTEN, the major negative regulator of the PI3K/AKT pathway induces a cellular senescence as a failsafe mechanism to defend against tumorigenesis, which is called PTEN-loss-induced cellular senescence (PICS). Although many studies have indicated that the mTOR pathway plays a critical role in cellular senescence, the exact functions of mTORC1 and mTORC2 in PICS are not well understood. In this study, we show that mTOR acts as a critical relay molecule downstream of PI3K/AKT and upstream of p53 in PICS. We found that PTEN depletion induces cellular senescence via p53-p21 signaling without triggering DNA damage response. mTOR kinase, a major component of mTORC1 and mTORC2, directly binds p53 and phosphorylates it at serine 15. mTORC1 and mTORC2 compete with MDM2 and increase the stability of p53 to induce cellular senescence via accumulation of the cell cycle inhibitor, p21. In embryonic fibroblasts of PTEN-knockout mice, PTEN deficiency also induces mTORC1 and mTORC2 to bind to p53 instead of MDM2, leading to cellular senescence. These results collectively demonstrate for the first time that mTOR plays a critical role in switching cells from proliferation signaling to senescence signaling via a direct link between the growth-promoting activity of AKT and the growth-suppressing activity of p53.

CD11b regulates antibody class switching via induction of AID.

The integrin CD11b, which is encoded by the integrin subunit alpha M (ITGAM), is primarily expressed on the surface of innate immune cells. Genetic variations in ITGAM are among the strongest risk factors for systemic lupus erythematosus, an autoimmune disease characterized by the presence of autoantibodies. However, the regulatory function of CD11b in the antibody responses remains unclear. Here, we report the induction of CD11b in activated B2 B cells and define its unexpected role in immunoglobulin heavy chain class switch recombination (CSR). LPS-activated B cells lacking CD11b yielded fewer IgG subtypes such as IgG1 and IgG2a in vitro, and immunization-dependent CSR and affinity maturation of antibodies were severely impaired in CD11b-deficient mice. Notably, we observed the reduced expression of activation-induced cytidine deaminase (AID), an enzyme that initiates CSR and somatic hypermutation, and ectopic expression of AID was sufficient to rescue the defective CSR of CD11b-deficient B cells. LPS-induced phosphorylation of NF-κB p65 and IκBα was attenuated in CD11b-deficient B cells, and hyperactivation of IκB kinase 2 restored the defective AID expression and CSR, which implied that CD11b regulates the NF-κB-dependent induction of AID. Overall, our experimental evidence emphasized the function of CD11b in antibody responses and the role of CD11b as a vital regulator of CSR.

A green preparation of nitrogen doped graphene using urine for oxygen reduction in alkaline fuel cells.

A simple, eco-friendly and efficient harmless chemical approach has been developed for the simultaneous nitrogen (N) doping and reduction of graphene oxide (GO) by cost free human urine using simple refluxing. Large-scale preparation of graphene has been hindered largely by several issues, such as highly toxic reducing agents that are harmful to human health and environment, complicated reduction process and costly chemicals. Human urine is a natural precursor of urea with no cost. In this process, the NH3 has acted as not only reducing but also doping agent that produced via thermal decomposition of urea, while the N doping level of ~11.1 at% is achieved. For the first time we have used urine as a reductant and doping agent in such a high class chemical technology. The simultaneous reduction and N-doping of GO using urine (denoted as UNG) have confirmed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and UV-vis spectroscopy. The resultant UNG has demonstrated to show remarkable electrocatalytic activity toward oxygen reduction reaction (ORR) with better fuel selectivity, and stability than that of the commercially available 20 wt% Pt/C electrode using cyclic voltammetry (CV) and chronoamperometry.

A lead(II)-selective PVC membrane based on a Schiff base complex of N,N'-bis(salicylidene)-2,6-pyridinediamine.

PVC membrane electrodes for lead ion based on N,N'-bis(salicylidene)-2,6-pyridinediamine as membrane carrier were prepared. Among their membranes, a membrane electrode (m-3) containing o-NPOE as a plasticizer and 50mol% additive displays an excellent Nernstian response (29.4mV/decade) and the limit of detection of -loga (M) = 6.04 to Pb(2+) in Pb(NO(3))(2) solutions at room temperature. It has a rapid response time within 10s over the entire concentration range. The proposed electrode revealed good selectivity and response for Pb(2+) over a wide variety of other metal ions in a pH 5.0 buffer solutions, and good reproducibility of base line in subsequent measurements.