Physiological responses to acute experimental hypoxia in the air-breathing Indian catfish, Clarias batrachus (Linnaeus, 1758)

With an aim to study the mechanism of adaptation to acute hypoxic periods by hypoxia-tolerant catfish, Clarias batrachus, the mass-specific metabolic rate (VO₂) along with its hematological parameters, metabolic response and antioxidant enzyme activities were studied. During progressive hypoxia, C. batrachus was found to be an oxyconformer and showed a steady decline in its aquatic oxygen consumption rate. When C. batrachus was exposed for different periods at experimental hypoxia level (0.98?±?0.1 mg/L, DO), hemoglobin and hematocrit concentrations were increased, along with decrease in mean cellular hemoglobin concentration, which reflected a physiological adaptation to enhance oxygen transport capacity. Significant increase in serum glucose and lactate concentration as well as lactate dehydrogenase activity was observed. Antioxidant enzymes were found to operate independently of one another, while total glutathione concentration was unaffected in any of the tissues across treatments. These observations suggested that hypoxia resulted in the development of oxidative stress and C. batrachus was able to respond through increase in the oxygen carrying capacity, metabolic depression and efficient antioxidant defense system to survive periods of acute hypoxia.     

Distribution of Voltage-Gated Sodium Channel (Nav) Alleles among the Aedes aegypti Populations In Central Java Province and Its Association with Resistance to Pyrethroid Insecticides

The emergence of insecticide resistant Aedes aegypti mosquitoes has hampered dengue control efforts. WHO susceptibility tests, using several pyrethroid compounds, were conducted on Ae. aegypti larvae that were collected and raised to adulthood from Semarang, Surakarta, Kudus and Jepara in Java. The AaNa_V gene fragment encompassing kdr polymorphic sites from both susceptible and resistant mosquitoes was amplified, and polymorphisms were associated with the resistant phenotype. The insecticide susceptibility tests demonstrated Ae, aegypti resistance to the pyrethroids, with mortality rates ranging from 1.6%–15.2%. Three non-synonymous polymorphisms (S989P, V1016G and F1534C) and one synonymous polymorphism (codon 982) were detected in the AaNa_V gene. Eight AaNa_V alleles were observed in specimens from Central Java. Allele 3 (SGF) and allele 7 (PGF) represent the most common alleles found and demonstrated strong associations with resistance to pyrethroids (OR = 2.75, CI: 0.97–7.8 and OR = 7.37, CI: 2.4–22.5, respectively). This is the first report of 8 Ae. aegypti AaNa_V alleles, and it indicates the development of resistance in Ae. aegypti in response to pyrethroid insecticide-based selective pressure. These findings strongly suggest the need for an appropriate integrated use of insecticides in the region. The 989P, 1016G and 1534C polymorphisms in the AaNa_V gene are potentially valuable molecular markers for pyrethroid insecticide resistance monitoring.     

Who shall I say is calling? Validation of a caller recognition procedure in Bornean flanged male orangutan (Pongo pygmaeus wurmbii) long calls

Acoustic individual discrimination has been demonstrated for a wide range of animal taxa. However, there has been far less scientific effort to demonstrate the effectiveness of automatic individual identification, which could greatly facilitate research, especially when data are collected via an acoustic localization system (ALS). In this study, we examine the accuracy of acoustic caller recognition in long calls (LCs) emitted by Bornean male orangutans (Pongo pygmaeus wurmbii) derived from two data-sets: the first consists of high-quality recordings taken during individual focal follows (N = 224 LCs by 14 males) and the second consists of LC recordings with variable microphone-caller distances stemming from ALS (N = 123 LCs by 10 males). The LC is a long-distance vocalization. We therefore expect that even the low-quality test-set should yield caller recognition results significantly better than by chance. Automatic individual identification was accomplished using software originally developed for human speaker recognition (i.e. the MSR identity toolbox). We obtained a 93.3% correct identification rate with high-quality recordings, and 72.23% with recordings stemming from the ALS with variable microphone-caller distances (20–420 m). These results show that automatic individual identification is possible even though the accuracy declines compared with the results of high-quality recordings due to severe signal degradations (e.g. sound attenuation, environmental noise contamination, and echo interference) with increasing distance. We therefore suggest that acoustic individual identification with speaker recognition software can be a valuable tool to apply to data obtained through an ALS, thereby facilitating field research on vocal communication.     

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for anticancer potential using human colon adenocarcinoma (HT29) and human kidney adenocarcinoma (A498) cancer cell lines. Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 were the most potent as determined by examination of morphological features and by inhibition of growth by graded concentrations of crude extracts and thin-layer chromatography (TLC) eluates. Cell cycle analysis and multiplex assays using cancer biomarkers also confirmed Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as cancer drug resources. Apoptotic studies in the cells of A498 (cancer) and MCF-10A (normal human epithelial) exposed to crude extracts and TLC fractions revealed no significant impact on MCF-10A cells emphasizing its importance in the development of anticancer drug. Identification of biomolecules from these extracts are in progress.     

Influence of Soil Variation on Diosgenin Content Profile in Costus speciosus from Indo-Gangetic Plains

Costus speciosus is a rich source of commercially important compound Diosgenin, distributed in different regions of India. The present investigation was aimed to quantify diosgenin through High Performance Thin Layer Chromatography in 34 germplasms of Costus speciosus and also to identify the superior sources and to correlate the macronutrients of rhizospheric soil. The starch content varied in microscopic examination and correlated inversely (r=−0.266) with diosgenin content. Findings revealed that the extraction process with acid hydrolysis yielded higher diosgenin content (0.15–1.88 %) as compared to non-hydrolysis (0.009–0.368 %) procedure. Germplasms from Uttar Pradesh (NBCS-4), Jharkhand (NBCS-39) and Bihar (NBCS-2) were identified as elite chemotypes based on hierarchical clustering analysis. The phosphorous content of respective rhizospheric soil correlated positively (r=0.742) with diosgenin content. Findings of present study are useful to identify the new agrotechniques. The elite germplasms can also be used as quality planting material for large scale cultivation in order to assure a sustained supply to the herbal drug industry.     

Augmentation of systemic resistance and secondary metabolites by chitinolytic microbes in Withania somnifera against Meloidogyne incognita

Ashwagandha (Withania somnifera L. Dunal), a therapeutically imperative herb is known for its useful steroidal lactones (withanolide and withaferin) and acyl steryl glycosides. The plant is a highly susceptible host for the plant parasitic nematode, Meloidogyne incognita. Selected chitinolytic microbes, namely Cellulosimicrobium cellulans MTN13, Flavobacterium johnsoniae MTN 20, Chitiniphilus sp. MTN22 and Streptomyces sp. MTN14, alone and in combination for M. incognita management and enhancement of secondary metabolites in W. somnifera cv. Poshita were evaluated. A significant enhancement in biomass yield (1.9-fold) and disease diminution (2.7-fold) was found in the dual microbial treatment Streptomyces sp. and Chitiniphilus sp. with respect to the untreated inoculated control plants. A significant augmentation (2.7- and 2.0-fold, respectively) in withanolide A and withaferin A was also found in the same treatment. The studies revealed increment of defence variables 1.1- to 1.3-fold and 1.6- to 2.1-fold in single- and dual-microbe treatments, respectively, than the untreated inoculated plants. The stimulation of the phenylpropanoid pathway and phenolics accumulation was the maximum at 5 days post inoculation (dpi), whereas antioxidant enzymes activities were the highest at 7?dpi. The results thus highlight a possible new function of chitinolytic microbes alone and in combinations that can effectively manage M. incognita-induced stress along with enhanced active molecules of W. somnifera.     

EST-based identification of immune-relevant genes from spleen of Indian catfish, Clarias batrachus (Linnaeus, 1758)

A normalized cDNA library from spleen of Indian catfish, Clarias batrachus, was constructed with a redundancy factor of 2.29. A total of 2045 clones from the library were single-pass sequenced, which generated 1937 high quality ESTs with an average read length of approximately 700 bp. Based on sequence similarities, 65 ESTs were found to be associated with immune functions, which were mainly associated with response to stress, response to chemical stimulus, cellular response to stimulus, response to external stimulus, immune response and regulation of response to stimulus. The immune-relevant gene for CD141, thrombomodulin, has been identified in Teleosts for the first time. Six EST-SSRs and three SNPs were found associated with eight immune-relevant genes. These markers associated with important immune genes would be useful for the identification of trait associated alleles for marker-assisted selection. The identification of the putative immune-related genes provides a meaningful framework to understand the Indian catfish immune system and defense mechanisms.