Patterns and trends in two decades of research on Nepal’s mammalian fauna (2000–2019): examining the past for future implications

Nepal is a global biodiversity hotspot, supporting 213 mammal species with diverse habitats across various landscape types, from the lowland Terai to the high Himalayas. Studies of Nepal’s mammalian fauna are not evenly distributed and better understanding of past biases towards some species, research themes and locations can provide better strategic direction for future research investments. Therefore, we reviewed 575 scientific articles on mammals in Nepal, published between 2000 and 2019 and compiled these in March 2020, to examine trends, patterns and gaps, and pave future plans for mammalian research in Nepal. A positive increase in the number of publications (β?=?0.27?±?0.02SD, P?<?0.00) was observed, with a more than threefold increase between 2010 and 2019 compared to 2000–2009 (t?=?? 6.26, df?=?12.21, P?<?0.000). Analysis of these documents revealed that mammalian researches favored large flagship, threatened species of carnivores inside Nepal’s protected area system. Geographically, mammalian research was not uniform in Nepal, as most studies were concentrated in Bagmati Province and in the Terai and Chure region. Baseline surveys and ecological studies were more common types of research, while studies on the impact of climate change and wildlife trade and poaching, are scant, which deserves a future look. While these studies shape current mammalogy in Nepal, studies of small, uncharismatic species, and in areas outside protected areas and other provinces except Bagmati, Lumbini and Province One are severely lacking. The research identified habitat loss, degradation and human-wildlife conflict as the major threats to the survival of mammalian species in Nepal. Therefore, redesigning and strict implementation of policies based on habitat management and human-wildlife co-existence, including other threat mitigation measures, are warranted. To address knowledge gaps, the prioritization of future research and funding should be focused on relatively unexplored research themes and under-researched provinces. This approach will help to re-align the research focus with the current need, and assist to fully understand and effectively conserve the wealth of mammalian diversity that Nepal holds.

     

Differential Chlorate Inhibition of Chaetomium globosum Germination, Hyphal Growth, and Perithecia Synthesis

Chaetomium globosum Kunze:Fr is a dermatophytic, dematiaceous fungus that is ubiquitous in soils, grows readily on cellulolytic materials, and is commonly found on water-damaged building materials. Chlorate affects nitrogen metabolism in fungi and is used to study compatibility among anamorphic fungi by inducing nit mutants. The effect of chlorate toxicity on C. globosum was investigated by amending a modified malt extract agar (MEA), oat agar, and carboxymethyl cellulose agar (CMC) with various levels of potassium chlorate (KClO₃). C. globosum perithecia production was almost completely inhibited (90–100?%) at low levels of KClO₃ (0.1?mM) in amended MEA. Inhibition of perithecia production was also observed on oat agar and CMC at 1?and 10?mM, respectively. However, hyphal growth in MEA was only inhibited 20?% by 0.1–100?mM KClO₃ concentrations. Hyphal growth was never completely inhibited at the highest levels tested (200?mM). Higher levels of KClO₃ were needed on gypsum board to inhibit perithecia synthesis. In additional experiments, KClO₃ did not inhibit C. globosum, Fusarium oxysporum, Aspergillus niger, Penicillum expansum, and airborne fungal spore germination. The various fungal spores were not inhibited by KClO₃ at 1–100?mM levels. These results suggest that C. globosum perithecia synthesis is more sensitive to chlorate toxicity than are hyphal growth and spore germination. This research provides basic information that furthers our understanding about perithecia formation and may help in developing control methods for fungal growth on building materials.     

Allorecognition Triggers Autophagy and Subsequent Necrosis in the Cnidarian Hydractinia symbiolongicarpus

Transitory fusion is an allorecognition phenotype displayed by the colonial hydroid Hydractinia symbiolongicarpus when interacting colonies share some, but not all, loci within the allorecognition gene complex (ARC). The phenotype is characterized by an initial fusion followed by subsequent cell death resulting in separation of the two incompatible colonies. We here characterize this cell death process using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and continuous in vivo digital microscopy. These techniques reveal widespread autophagy and subsequent necrosis in both colony and grafted polyp assays. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays and ultrastructural observations revealed no evidence of apoptosis. Pharmacological inhibition of autophagy using 3-methyladenine (3-MA) completely suppressed transitory fusion in vivo in colony assays. Rapamycin did not have a significant effect in the same assays. These results establish the hydroid allorecognition system as a novel model for the study of cell death.     

Towards a critical understanding of the photosystem II repair mechanism and its regulation during stress conditions

Photosystem II (PSII) is vulnerable to high light (HL) illumination resulting in photoinhibition. In addition to photoprotection mechanisms, plants have developed an efficient PSII repair mechanism to save themselves from irreversible damage to PSII under abiotic stresses including HL illumination. The phosphorylation/dephosphorylation cycle along with subsequent degradation of photodamaged D1 protein to be replaced by the insertion of a newly synthesized copy of D1 into the PSII complex, is the core function of the PSII repair cycle. The exact mechanism of this process is still under discussion. We describe the recent progress in identifying the kinases, phosphatases and proteases, and in understanding their involvement in the maintenance of thylakoid structure and the quality control of proteins by PSII repair cycle during photoinhibition.     

Omega-3 fatty acids and metabolic syndrome: Effects and emerging mechanisms of action

Epidemiological, human, animal, and cell culture studies show that n−3 fatty acids, especially α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), reduce the risk factors of cardiovascular diseases. EPA and DHA, rather than ALA, have been the focus of research on the n−3 fatty acids, probably due to the relatively inefficient conversion of ALA to EPA and DHA in rodents and humans. This review will assess our current understanding of the effects and potential mechanisms of actions of individual n−3 fatty acids on multiple risk factors of metabolic syndrome. Evidence for pharmacological responses and the mechanism of action of each of the n−3 fatty acid trio will be discussed for the major risk factors of metabolic syndrome, especially adiposity, dyslipidemia, insulin resistance and diabetes, hypertension, oxidative stress, and inflammation. Metabolism of n−3 and n−6 fatty acids as well as the interactions of n−3 fatty acids with nutrients, gene expression, and disease states will be addressed to provide a rationale for the use of n−3 fatty acids to reduce the risk factors of metabolic syndrome.     

Effects of ALA,EPA and DHA in high-carbohydrate,high-fat diet-induced metabolic syndrome in rats

We compared the cardiovascular, hepatic and metabolic responses to individual dietary n-3 fatty acids (α-linolenic acid, ALA; eicosapentaenoic acid, EPA; and docosahexaenoic acid, DHA) in a high-carbohydrate, high-fat diet-induced model of metabolic syndrome in rats. Additionally, we measured fatty acid composition of plasma, adipose tissue, liver, heart and skeletal muscle in these rats. The same dosages of ALA and EPA/DHA produced different physiological responses to decrease the risk factors for metabolic syndrome. ALA did not reduce total body fat but induced lipid redistribution away from the abdominal area and favorably improved glucose tolerance, insulin sensitivity, dyslipidemia, hypertension and left ventricular dimensions, contractility, volumes and stiffness. EPA and DHA increased sympathetic activation, reduced the abdominal adiposity and total body fat and attenuated insulin sensitivity, dyslipidemia, hypertension and left ventricular stiffness but not glucose tolerance. However, ALA, EPA and DHA all reduced inflammation in both the heart and the liver, cardiac fibrosis and hepatic steatosis. These effects were associated with complete suppression of stearoyl-CoA desaturase 1 activity. Since the physiological responses to EPA and DHA were similar, it is likely that the effects are mediated by DHA with EPA serving as a precursor. Also, ALA supplementation increased DHA concentrations but induced different physiological responses to EPA and DHA. This result strongly suggests that ALA has independent effects in metabolic syndrome, not relying on its metabolism to DHA.     

Seedling and adult‐plant stage resistance of a world collection of barley genotypes to stripe rust

Barley stripe rust caused by Puccinia striiformis f.sp. hordei (PSH) is one of the major diseases in barley production regions worldwide. A total of 336 barley genotypes with diverse genetic backgrounds targeted for low‐input barley production were tested for seedling and adult‐plant stage resistance against six PSH races (0S0, 0S0‐1, 1S0, 4S0, 5S0 and 7S0) originated from India. The seedling resistance was evaluated by inoculating the barley genotypes with six races separately under controlled conditions in Shimla, India. The same barley genotypes were evaluated for adult‐plant stage resistance in the Agricultural Research Station (ARS) of Rajasthan Agriculture University, Durgapura, Rajasthan, India. Out of the 336 barley genotypes tested for seedling resistance, 119 (35.4%), 101 (30.1%), 87 (25.9%), 100 (29.8%), 91 (27.1%) and 70 (20.8%) genotypes were resistant to races 0S0, 0S0‐1, 1S0, 4S0, 5S0 and 7S0, respectively. In the field, 102 (30.3%) genotypes showed the resistance response of which 18 (5.3%) genotypes were highly resistant to PSH. Barley genotypes AM‐14, AM‐177, AM‐37, AM‐120, AM‐300, AM‐36, AM‐103, AM‐189, AM‐291, AM‐275 and AM‐274 showed resistance response to all six races at seedling and adult‐plant stages. Seedling resistance reported in the current study is effective against the newly emerged race 7S0 and previously reported five races in India. Therefore, resistant barley genotypes identified in the current study provided effective protection against all six races at seedling and adult‐plant stages. The stripe rust resistance identified in the current studies may be potential donors of stripe rust resistance to barley breeding programmes in India and elsewhere.