Environmental DNA (eDNA): Powerful technique for biodiversity conservation

Environmental DNA metabarcoding is a non-invasive method for discovering and identifying rare and endangered species in a variety of ecosystems, including aquatic environments, based on the retrieval of genetic traces emitted into the environment by animals. Environmental (e) DNA research has grown in popularity over the last decade as a result of a rise in the number of studies that employ DNA taken from the environment, particularly in freshwater and marine ecosystems. In terms of detecting diversity patterns, we may claim that DNA retrieved from the environment (eDNA) is altering the game. For resource management in fisheries, information on species composition and biomass/abundance of commercially and noncommercially harvested species is critical. The eDNA is a truly non-invasive method that inflicts no damage on the species or habitats under study even during sampling, the eDNA technique never harms any ecosystems or threatened species. This novel molecular method never affects any endangered species or ecosystem during sampling. Environmental DNA analysis has become more widely accepted and is used in the detection of the presence and absence of aquatic macrofauna, such as freshwater and marine fish. This review study may aid researchers in better understanding the current state of eDNA technology. Despite the fact that various scientists have used eDNA to investigate the worldwide biodiversity of aquatic environments, no one in India is focusing on this new technology. We conclude that the eDNA technique has the potential to become a next-generation tool for biodiversity research and aquatic ecosystem conservation.     

Selection and genetic (co)variance in bighorn sheep

Genetic theory predicts that directional selection should deplete additive genetic variance for traits closely related to fitness, and may favor the maintenance of alleles with antagonistically pleiotropic effects on fitness-related traits. Trait heritability is therefore expected to decline with the degree of association with fitness, and some genetic correlations between selected traits are expected to be negative. Here we demonstrate a negative relationship between trait heritability and association with lifetime reproductive success in a wild population of bighorn sheep (Ovis canadensis) at Ram Mountain, Alberta, Canada. Lower heritability for fitness-related traits, however, was not wholly a consequence of declining genetic variance, because those traits showed high levels of residual variance. Genetic correlations estimated between pairs of traits with significant heritability were positive. Principal component analyses suggest that positive relationships between morphometric traits constitute the main axis of genetic variation. Trade-offs in the form of negative genetic or phenotypic correlations among the traits we have measured do not appear to constrain the potential for evolution in this population.     

Toward a more trait-centered approach to diffuse (co)evolution

How species evolve depends on the communities in which they are embedded. Here, we briefly review the ideas underlying concepts of diffuse coevolution, evolution, and selection. We discuss criteria to identify when evolution will be diffuse. We advocate a more explicitly trait-oriented approach to diffuse (co)evolution, and discuss how considering effects of interacting species on fitness alone tells us little about evolution. We endorse the view that diffuse evolution occurs whenever the response to selection by one interacting species on a given trait is altered by the presence of a second interacting species. Building on the work of others, we clarify and expand the criteria for diffuse evolution and present a simple experimental design that will allow the detection of diffuse selection. We argue that a greater focus on selection on specific traits and the evolutionary response to that selection will improve our conceptual understanding of how communities affect the evolution of species embedded within them.     

Microbial alpha-galactosidase (a review)

The review discusses properties, distribution and potential use of microbial alpha-galactosidase (alpha-D-galactoside galactohydrolase, EC 3.2.1.22), the enzyme catalyzing degradation of alpha-D-galactoside bonds. Recent years have witnessed many publications describing microbial alpha-galactosidase which, in contrast to the similar enzyme from higher plants, has been poorly studied. The microbial enzyme has certain specificities: a smaller substrate specificity, existence in one molecular form, etc. The present communication is an attempt to systematize the data about microbial alpha-galactosidase and to outline the most important investigations for the future.     

Coordination chemistry of co(II)-bleomycin: its investigation through NMR and molecular dynamics

Previous studies on the coordination chemistry of Co-bleomycin have suggested the secondary amine in beta-aminoalanine, the N5 and N1 nitrogens in the pyrimidine and imidazole rings, respectively, and the amide nitrogen in beta-hydroxyhistidine as equatorial ligands to the cobalt ion. The primary amine in beta-aminoalanine and the carbamoyl group of the mannose have been proposed alternatively as possible axial ligands. The first coordination sphere of Co(II) in Co(II)BLM has been investigated in the present study through the use of NMR and molecular dynamics calculations. The data collected from the NMR experiments are in agreement with the equatorial ligands previously proposed, and also support the participation of the primary amine as an axial ligand. The paramagnetic shifts of the gulose and mannose protons could suggest the latter as a second axial ligand. This possibility was investigated by way of molecular dynamics, with distance restraints derived from the relaxation times measured through NMR. The molecular dynamics results indicate that the most favorable structure is six-coordinate, with the primary amine and either the carbamoyl oxygen or a solvent molecule occupying the axial sites. The analysis of the structures previously derived for HOO-Co(III)-bleomycin and HOO-Co(III)-pepleomycin led us to propose the six-coordinate structure with only endogenous ligands, as the one held in solution by the Co(II) derivative of bleomycin.     

Trimethylene carbonate and epsilon-caprolactone based (co)polymer networks: mechanical properties and enzymatic degradation

High molecular weight trimethylene carbonate (TMC) and epsilon-caprolactone (CL) (co)polymers were synthesized. Melt pressed (co)polymer films were cross-linked by gamma irradiation (25 kGy or 50 kGy) in vacuum, yielding gel fractions of up to 70%. The effects of copolymer composition and irradiation dose on the cytotoxicity, surface properties, degradation behavior, and mechanical and thermal properties of these (co)polymers and networks were investigated. Upon incubation with cell culture medium containing extracts of (co)polymers and networks, human foreskin fibroblasts remained viable. For all (co)polymers and networks, cell viabilities were determined to be higher than 94%. The formed networks were flexible, with elastic moduli ranging from 2.7 to 5.8 MPa. Moreover, these form-stable networks were creep resistant under dynamic conditions. The permanent deformation after 2 h relaxation was as low as 1% after elongating to 50% strain for 20 times. The in vitro enzymatic erosion behavior of these hydrophobic (co)polymers and networks was investigated using aqueous lipase solutions. The erosion rates in lipase solution could be tuned linearly from 0.8 to 45 mg/(cm (2) x day) by varying the TMC to CL ratio and the irradiation dose. The copolymers and networks degraded essentially by a surface erosion mechanism.     

Microbial Resolution of (±)-Borneols

(±)-Bornyl acetate and (±)-isobornyl acetate were asymmetrically hydrolyzed by microorganisms to give (?)-borneol with (+)-bornyl acetate and (?)-isoborneol with (+)-isobornyl acetate although in low hydrolytic ratios. On the contrary (±)-bornyl chloroacetate and (±)-isobornyl chloroacetate were easily hydrolyzed by microorganisms to afford (?)-borneol and (?)-isoborneol with the acetate of their antipodes. Also, enzymatic hydrolysis of (±)-menthyl chloroacetate proceeded faster than that of (±)-menthyl acetate.     

Microbial transformation of (-)-carvone

The cyclic monoterpene ketone (-)-carvone was metabolized by the plant pathogenic fungus Absidia glauca. After 4 days of incubation, the diol 10-hydroxy-(+)-neodihydrocarveol was formed. The absolute configuration and structure of the crystalline substance was identified by means of X-ray diffraction and by spectroscopic techniques (MS, IR and NMR). The antimicrobial activity of the substrate and metabolite was assayed with human pathogenic microorganisms.     

Grafted radical (co)polymerization of water-soluble lignin derivatives with methyl acrylate

Synthesis of grafted copolymers of sodium lignosulfonate with methyl acrylate was performed by means of radical (co)polymerization. Mechanism of grafted radical (co)polymerization was proposed on the basis of IR spectroscopy data and functional analysis. Polyelectrolyte, hydrodynamic, polymolecular, and surfactant properties of water-soluble grafted copolymers were studied.     

Neospora caninum (Protozoa: apicomplexa) infections in mice

Groups of mice were given 0 mg, 4 mg, or 2 mg of methylprednisolone acetate (MPA) 7 days prior to, the day of, and 7 days after subcutaneous inoculation with 0 or 2 x 10(5) tachyzoites of Neospora caninum. Clinical signs of disease were seen only in mice given both MPA and N. caninum tachyzoites. Mice given 4 mg MPA and N. caninum tachyzoites developed severe disseminated neosporosis and most died or were killed when comatose 11-13 days postinoculation (PI). Acute pneumonia, polymyositis, encephalitis, hepatitis, and pancreatitis were the main lesions in these mice. Mice given 2 mg MPA and N. caninum developed mild pneumonia and many mice began showing neurological signs 14 days PI. Neurological signs consisted mainly of pronounced head-tilting and associated impairment of movement. Grossly visible 1-2-mm single or multiple, white areas of discoloration were seen in the brains of many of these mice. Encephalitis, ganglioradiculoneuritis, pneumonia, and polymyositis were the main changes seen in these mice. Tissue cysts of N. caninum were only seen in mice given 2 mg MPA and were first seen 21 days PI. Tissue cysts were 16-34 by 13-29 microns and had a 1.5-3.0-microns-thick cyst wall. Tissue cysts were seen only in the brain. Mice given 4 mg MPA and tachyzoites and host cells that had been frozen for 1 wk did not develop clinical signs of infection, indicating that freezing kills tachyzoites and that viruses or other agents were not involved in the genesis of disease seen in mice given MPA and viable tachyzoites.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microbial Resolution of (±)-Acyclic Alcohols

By selected microorganisms the acetates of the racemic sec-alcohols were asymmetrically hydrolyzed to optically active sec-alcohols and the acetates of their antipodes. Microbial hydrolysis of the acetates of the racemic prim-alcohols having an asymmetrical carbon atom at the β-position gave lower optically active alcohols and the acetates of their antipodes, but the acetates having an asymmetrical carbon atom at the γ-position were hydrolyzed only to give racemic alcohols.