10 research outputs found
A review on fisheries and conservation status of Asian Horseshoe crabs
Horseshoe crabs are the only extant xiphosurans and are believed to be morphologically
unchanged for more than 200 million years. Of the four extant species namely, Limulus
polyphemus, Tachypleus tridentatus, Tapinauchenius gigas and Carcinoscorpius rotundicauda,
the latter three are found in Asian waters. Recent evidences showed that Asian
horseshoe crabs are facing serious threats such as degradation of their spawning grounds
and habitat, environmental pollution, overexploitation as a culinary delicacy and biomedical
bleeding practices. Baseline data on the distribution and existing population of the wild
horseshoe crabs remain poorly known in several Asian regions. Several studies have clearly
revealed that pressure due to over-fshing of wild stock has increased tremendously in the
last decade. Due to an increase in demand for Tachypleus Amebocyte Lysate (TAL) analogous
to Limulus Amebocyte Lysate (LAL) in the United States, there is an urgent need to
comprehensively address their fshing and conservation measures in the Asian region. This
review addresses the overall studies on three species of Asian horseshoe crabs in relation
to their fshing practices, local exploitation of their wild stock either for human consumption
(or) by biomedical industries. The authors have structured the discussion on an international
scale to address the existing problems in fshing and conservation of horseshoe
crabs. Since no specifc regulatory force or legislative protection act or a policy to preserve
their natural stock are available to this date, this paper strongly recommends representative
countries to include horseshoe crabs under their wildlife protection act to avoid further
unsustainable exploitation of their wild population
End of Biological Mothers?
39-40Scientists at the University of Bath in the UK have demonstrated that the cellular components of a mother are not strictly required to create a biological offspring
Is Sex Reversal Common Phenomenon in Horseshoe Crabs Too?
The capacity of organisms to change their sex has evolved independently in several species. Sex change has been widely studied, but research approaches have differed and conclusions have often been specific. Although sex allocation theory provides a unifying framework for the study of sex change, this unity has not always been appreciated, Environmental sex reversal (ESR), which results in a mismatch between genotypic and phenotypic sex, is well documented in numerous species and may be induced by chemical exposure. In the present study, an attempt was made to hypothesize the phenomenon of sex reversal in both Asian species (Tachypleus gigas and Carcinoscorpius rotundicauda) of the horseshoe crab in accordance with the size of the animals. Our findings suggest that both Asian species of horseshoe crabs ultimately show a positive sign of sex reversal phenomenon, however, this hypothesis needs further confirmation by studying the hormonal changes at all moulting stages of the horseshoe cra
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Not AvailableC4 plants are superior to C3 plants in terms of productivity and limited photorespiration. PPDK (pyruvate orthophosphate dikinase) and NADP-ME (NADP-dependent malic enzyme) are two important photosynthetic C4-specific enzymes present in the mesophyll cells of C4 plants. To evaluate the effect of C4 enzymes in rice, we developed transgenic rice lines by separately introducing Setaria italica PPDK [SiPPDK] and S. italica ME [SiME] gene constructs under the control of the green tissue-specific maize PPDK promoter. Rice plant lines for both constructs were screened using the polymerase chain reaction (PCR), Southern hybridization, and expression analysis. The best transgenic plant lines for each case were selected for physiological and biochemical characterization. The results from qRT-PCR and enzyme activity analysis revealed higher expression and activity of both PPDK and NADP-ME genes compared with the nontransformed and empty-vector-transformed plants. The average photosynthetic efficiency of transgenic plant lines carrying the PPDK and NADP-ME genes increased by 18% and 12%, respectively, and was positively correlated with the increased accumulation of photosynthetic pigment. The decrease in Fv/Fm, increased electron transport rate (ETR), and increased photochemical quenching (qP) compared with nontransformed control plants suggest that transgenic rice plants transferred more absorbed light energy to photochemical reactions than wild-type plants. SiME-transgenic plants displayed reduced leaf malate content and superior performance under water deficit conditions. Interestingly, the transgenic plants showed yield enhancement by exhibiting increased plant height, panicle length, panicle weight and thousand grain weight. Overall, the exogenous foxtail millet C4 gene PPDK enhanced photosynthesis and yield to a greater extent than NADP-ME.Not Availabl
Nature Potential for COVID-19: Targeting SARS-CoV-2 Mpro Inhibitor with Bioactive Compound
Corona viruses were first
identified in 1931 and SARS-CoV-2 is the most recent. COVID-19 is a pandemic
that put most of the world on lockdown and the search for therapeutic drugs is
still on-going. Therefore, this study uses in silico screening to
identify natural bioactive compounds from fruits, herbaceous plants and marine
invertebrates that are able to inhibit protease activity in SARS-CoV-2(PDB:
6LU7). We have used various screening strategies such as drug likeliness,
antiviral activity value prediction, molecular docking, ADME (absorption,
distribution, metabolism, and excretion), molecular dynamics (MD) simulation
and MM/GBSA (molecular mechanics/generalized born and surface area continuum
solvation). 17 compounds were shortlisted using Lipinski’s rule. 5 compounds
revealed significantly good predicted antiviral activity values and out of them
only 2 compounds, Macrolactin A and Stachyflin, showed good binding energy values of -9.22 and -8.00
kcal/mol within the binding pocket,
catalytic residues (HIS 41 and CYS 145) of Mpro.
These two compounds were further analyzed for their ADME properties. The ADME evaluation of these 2 compounds
suggested that they could be effective as therapeutic agents for developing drugs for clinical trials. MD simulations showed that
protein-ligand complexes of Macrolactin A and Stachyflin were stable for 100
nano seconds. The MM/GBSA calculations of Mpro – Macrolactin A
complex indicated higher binding free energy (-42.58 ± 6.35 kcal/mol) with Mpro protein
target receptor (6LU7). DCCM and PCA analysis on the residual movement in the
MD trajectories confirmed the good stability on Macrolactin A bound state of
6LU7. This signify the stable conformation of 6LU7 with high binding energy
with Macrolactin A. Thus, this study showed that Macrolactin A could be an
effective therapeutical agent for SARS-CoV-2protease (6LU7) inhibition.
Additional in vitro and in vivo validations are needed to
determine efficacy and dose of Macrolactin A in biological systems.</p
Predicting Tachypleus gigas spawning distribution with climate change in northeast coast of India
Species distribution models are used to predict ideal grounds, species range, and spatial shifts in an ecology over a span of time. With an aim to use Maximum entropy model (MaxEnt), presence records and pseudo-absence points are used to predict the Tachypleus gigas spawning activity for 2030 and 2050 in northeast India. The bearings of sixty T. gigas spawning grounds identified in 2018 were inserted into ArcGIS v.10.1. Meanwhile, 19 environment
variables were inserted into MaxEnt v. 3.3.3, before the model performance was tested using receiver operational
characteristics and area under curve (AUC). With an AUC of 0.978,85% was achieved for isothermality (bio3) and
74% for temperature (x̄= average) of the wettest quarter (bio8), all of which were inserted into ArcGIS to produce
spatial maps. Although we learnt that T. gigas are still spawning in Odisha in 2030 and 2050, their distribution
range is predicted to shrink due to the coastal morphology change. The climate conditions in Odisha revolve with the monsoon, summer and winter seasons from which, temperature variations do not only influence the annual absence/presence of spawning adults but also, the survival of juveniles in natal beaches. The use of MaxEnt offers novelty to predict population sustainability of arthropods characterized by oviparous spawning (horseshoe crabs, turtles, terrapins and crocodiles) through which, the government of India can take advantage of the present data to initiate the coastal rehabilitation measures to preserve their spawning grounds
Macrolactin A as a novel inhibitory agent for SARS-CoV-2 Mpro: bioinformatics approach
COVID-19 is a disease that puts most of the world on lockdown and the search for therapeutic drugs is still ongoing. Therefore, this study used in silico screening to identify natural bioactive compounds from fruits, herbaceous plants, and marine invertebrates that are able to inhibit protease activity in SARS-CoV-2 (PDB: 6LU7). We have used extensive screening strategies such as drug likeliness, antiviral activity value prediction, molecular docking, ADME, molecular dynamics (MD) simulation, and MM/GBSA. A total of 17 compounds were shortlisted using Lipinski’s rule in which 5 compounds showed significant predicted antiviral activity values. Among these 5, only 2 compounds, Macrolactin A and Stachyflin, showed good binding energy of −9.22 and −8.00 kcal/mol, respectively, within the binding pocket of the Mpro catalytic residues (HIS 41 and CYS
145). These two compounds were further analyzed to determine their ADME properties. The ADME evaluation of these 2 compounds suggested that they could be effective in developing therapeutic drugs to be used in clinical trials. MD simulations showed that protein–ligand complexes of Macrolactin A and Stachyflin with the target receptor (6LU7) were stable for 100 nanoseconds. The MM/GBSA calculations of Mpro–Macrolactin A complex indicated higher binding free energy (−42.58 ± 6.35 kcal/mol).
Dynamic cross-correlation matrix (DCCM) and principal component analysis (PCA) on the residual movement in the MD trajectories further confirmed the stability of Macrolactin A bound state with 6LU7. In conclusion, this study showed that marine natural compound Macrolactin A could be an effective therapeutic inhibitor against SARS-CoV-2 protease (6LU7). Additional in vitro and in vivo validations are strongly needed to determine the efficacy and therapeutic dose of Macrolactin A in biological
systems