Rupjyoti Bharali

Noninvasive genetic monitoring of tiger (Panthera tigris tigris) population of Orang National Park in the Brahmaputra floodplain, Assam, India

The Brahmaputra Valley of Assam, India, is one of the prime habitats for the endangered Royal Bengal tiger Panthera tigris tigris. With dwindling global population, estimation of the minimum number of tigers has always been a curiosity to wildlife researchers as well as to protected area managers. In the present study, DNA-based techniques were used for identifying individual tigers present in Orang National Park of Assam, from 57 faecal samples collected during February 2009. Orang National Park stands as an island of a single forest patch along the north bank of river Brahmaputra. The present study confirms the presence of 17 individual tigers in Orang National Park, with five male and 12 female. DNA-based capture–recapture analysis yielded minimum range estimate of 18 and 19 individuals, with possible overestimates of population size following two models of capture probability in CAPWIRE. The results of our genetic counting of tigers are compared with the estimates of 19 tigers based on pugmark analysis by the state Forest Department in 2000 and an independent capture–recapture estimate of 14 (±3.6) individuals based on photographic identity study in 2009. Looking at high mortality of tigers in the area, with 19 reported deaths during 2000 to 2009, our results indicate high individual turnover in the area. This study shows that Orang National Park harbours a healthy breeding population of tigers. However, the possibility of a source-sink dynamics operating in the landscape could not be ruled out, with possible immigration from nearby Kaziranga National Park on the south bank of Brahmaputra, which has the highest reported density of the species in the world.

Melatonin biosynthesizing enzyme genes and clock genes in ovary and whole brain of zebrafish (Danio rerio): Differential expression and a possible interplay.

The present study on zebrafish (Danio rerio) is the first attempt to demonstrate the circadian mRNA expression of melatonin biosynthesizing enzyme genes (Tph1a, Aanat1, Aanat2 and Hiomt) and clock associated genes (Bmal1a, Clock1a, Per1b, Per2 and Cry2a) in the ovary with a comparison to whole brain in normal (LD=12h L:12h D) and altered photic conditions (continuous dark, DD; continuous light, LL). Moreover, the present study also confirmed the ability of zebrafish ovary to biosynthesize melatonin both in vivo and in vitro with a significant difference at day and night. qRT-PCR analysis of genes revealed a dark acrophase of Aanat2 in both organs while Tph1 is in whole brain in LD condition. On the contrary, Bmal1a and Clock1a giving their peak in light, thereby showing a negative correlation with Tph1a and Aanat2. In LD-ovary, the acrophase of Tph1a, Bmal1a and Clock1a is in light and thus display a positive correlation. This trend of relationship in respect to Tph1a is not changing in altered photic conditions in both organs (except in DD-ovary). On the other hand this association for Aanat2 is varying in ovary under altered photic conditions but only in DD-whole brain. Both in LD and LL the expression of Aanat2 in brain presenting an opposite acrophase with both Bmal1a and Clock1a of ovary and consequently displaying a strong negative correlation among them. Interestingly, all ovarian clock associated genes become totally arrhythmic in DD, representing a loss of correlation between the melatonin synthesizing genes in brain and clock associated genes in ovary. The result is also indicating the formation of two heterodimers namely Clock1a:Bmal1a and Per2:Cry2a in the functioning of clock genes in both organs, irrespective of photic conditions, as they are exhibiting a strong significant positive correlation. Collectively, our data suggest that ovary of zebrafish is working as peripheral oscillator having its own melatonin biosynthesizing machinery and signifying a possible correlation with central oscillating system in various photic conditions.

Fabrication and characterization of biomaterial film from gland silk of muga and eri silkworms

This study discusses the possibilities of liquid silk (Silk gland silk) of Muga and Eri silk, the indigenous non mulberry silkworms of North Eastern region of India, as potential biomaterials. Silk protein fibroin of Bombyx mori, commonly known as mulberry silkworm, has been extensively studied as a versatile biomaterial. As properties of different silk-based biomaterials vary significantly, it is important to characterize the non mulberry silkworms also in this aspect. Fibroin was extracted from the posterior silk gland of full grown fifth instars larvae, and 2D film was fabricated using standard methods. The films were characterized using SEM, Dynamic contact angle test, FTIR, XRD, DSC, and TGA and compared with respective silk fibers. SEM images of films reveal presence of some globules and filamentous structure. Films of both the silkworms were found to be amorphous with random coil conformation, hydrophobic in nature, and resistant to organic solvents. Non mulberry silk films had higher thermal resistance than mulberry silk. Fibers were thermally more stable than the films. This study provides insight into the new arena of research in application of liquid silk of non mulberry silkworms as biomaterials.

Probiotics - the versatile functional food ingredients

Probiotics are live microbes which when administered in adequate amounts as functional food ingredients confer a health benefit on the host. Their versatility is in terms of their usage which ranges from the humans to the ruminants, pigs and poultry, and also in aquaculture practices. In this review, the microorganisms frequently used as probiotics in human and animal welfare has been described, and also highlighted are the necessary criteria required to be fulfilled for their use in humans on the one hand and on the other as microbial feed additives in animal husbandry. Further elaborated in this article are the sources from where probiotics can be derived, the possible mechanisms by which they act, and their future potential role as antioxidants is also discussed.

Anticancer Activity of Garcinia morella on T-Cell Murine Lymphoma Via Apoptotic Induction

Traditional knowledge (TK) based medicines have gained worldwide attention and presently the scientific community is focussing on proper pharmacological validation and identification of lead compounds for the treatment of various diseases. The North East region of India is the home of valuable traditional herbal remedies. Garcinia morella Desr. (Guttiferae) is one such medicinal plant used by traditional healers for the treatment of inflammatory disorders. The present study was aimed to evaluate the antioxidant and anticancer activity of methanol extracts of the leaf, bark and fruit of G. morella (GM) in different in vitro and in vivo experimental conditions. The results of this study showed that GM methanol extracts possessed in vitro antioxidant and anticancer properties, where the fruit extract (GF) showed maximum activity. The anticancer activity was further confirmed by the results of in vivo administration of GF (200 mg/kg) for ten days to Dalton’s lymphoma (DLA) induced mice. GF extract significantly increased the mean survival time (MST) of the animals, decreased the tumor volume and restored the hematological and biochemical parameters. The present study for the first time reported the anticancer property of GF on DLA. Further from the experiments conducted to elucidate the mechanism of action of GF on DLA, it can be concluded that GF exerts its anticancer effect through induction of caspases and DNA fragmentation that ultimately leads to apoptosis. However, further experimentation is required to elucidate the active principle and validate these findings in various in vivo settings.

Melatonin bio-synthesizing enzyme genes (Tph1, Aanat1, Aanat2, and Hiomt) and their temporal pattern of expression in brain and gut of a tropical carp in natural environmental conditions

Abstract The study demonstrates the temporal pattern of expression of melatonin bio-synthesizing enzyme genes (Tph1, Aanat1, Aanat2, and Hiomt) in the brain and gut of a tropical carp (Catla catla) on a daily and seasonal basis under natural photo-thermal conditions. The measurement of melatonin in brain and gut (both in vivo and in vitro) demonstrated a higher content in gut, with evidence of melatonin bio-synthesizing machinery in both tissues. All melatonin bio-synthesizing gene expressions in these two tissues were negatively correlated (except Aanat1 in brain and Hiomt in the gut) with the water temperature on an annual cycle. The higher expression of Aanat2 gene, rather than Aanat1, signifies the importance of Aanat2 isoform in the melatonin production in tropical carp. Furthermore, the Aanat2 and Hiomt genes are highly expressed in the gut. Analysis of the rhythm and acrophase of expression of these genes in the brain and gut imply a pineal-independent melatonin synthesizing machinery in these two organs, possibly involving both environmental and endogenous cues for the regulation of melatonin rhythm to synchronize the physiology of the animal.

Interaction of melatonin and gonadotropin‐inhibitory hormone on the zebrafish brain‐pituitary‐reproductive axis

Circadian cycles and photoperiod are known to influence reproductive physiology in several animals. Neuropeptides, such as gonadotropin‐inhibitory hormone (GNIH) and gonadotropin‐releasing hormone (GNRH), are influenced by melatonin in birds and mammals. The present study demonstrates the role of melatonin in oocyte maturation in the zebrafish (Danio rerio), via the brain‐pituitary‐reproductive axis, under different photic conditions. Melatonin was significantly higher both in the whole brain and ovary under continuous dark (DD) compared to continuous light (LL) conditions. Transcription of gnih in the brain was high in LL, but low in DD; similarly, melatonin exogenous treatment reduced gnih in cultured brain in a dose‐dependent manner. Expression of gnrh3, however, was high in both continuous photic conditions (DD and LL), whereas fshb and lhb were high only during DD. kiss2, another neuropeptide, was high in LL, but kiss1 remain unchanged among the conditions. At the gonad level, expression of fshr, lhcgr, mtnr1aa, and mtnr1ab tracked with the expression of their respective ligand in DD and LL. The expression of mprb is high in DD ovary, although intra‐ovarian growth factors (tgfb1a and bmp15) were low. The measured increased percentages of germinal vesicle breakdown, expression of Cyclin B1, and reduced Cdc2p34 phosphorylation are consistent with increased maturation in the dark. Our study thus links melatonin to the inhibition of gnih in the brain‐pituitary‐reproductive axis of zebrafish in response to photic conditions.

Alleviation of drought stress in pulse crops with ACC deaminase producing rhizobacteria isolated from acidic soil of Northeast India

The agricultural crops are often affected by the scarcity of fresh water. Seasonal drought is a major constraint on Northeast Indian agriculture. Almost 80% of the agricultural land in this region is acidic and facing severe drought during the winter period. Apart from classical breeding and transgenic approaches, the application of plant-growth-promoting bacteria (PGPB) is an alternative strategy for improving plant fitness under stressful conditions. The 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing PGPB offer drought stress tolerance by regulating plant ethylene levels. The aim of the present study was to evaluate the consortium effect of three ACC-deaminase producing rhizobacteria – Ochrobactrum pseudogrignonenseRJ12, Pseudomonas sp.RJ15 and Bacillus subtilisRJ46 on drought stress alleviation in Vigna mungo L. and Pisum sativum L. Consortium treatment significantly increase seed germination percentage, root length, shoot length, and dry weight of treated plants. An elevated production of reactive oxygen species scavenging enzymes and cellular osmolytes; higher leaf chlorophyll content; increase in relative water content and root recovery intension were observed after consortium treatment in comparison with the uninoculated plants under drought conditions. The consortium treatment decreased the ACC accumulation and down-regulated ACC-oxidase gene expression. This consortium could be an effective bio-formulator for crop health improvement in drought-affected acidic agricultural fields.

Cloning, phylogenetic analysis and tissue distribution of melatonin bio-synthesizing enzyme genes (Tph1, Aanat1, Aanat2 and Hiomt) in a tropical carp, Catla catla

Abstract The surface dwelling tropical carp Catla catla is gaining importance as a model for the study on the impact of ever-changing aquatic environment as well as chronobiology. Melatonin is the only chronobiotic molecule and act as the neurohormonal messenger in the synchronization of environmental stimuli and the body physiology. Therefore, the sequence analysis of the major enzymes involved in the bio-synthesis of this indole amine is the prime requisite. The present study is an attempt to clone the full-length sequences of melatonin biosynthesising enzyme genes, Tryptophan hydroxylase 1 (Tph1), Arylalkylamine N-acetyltransferase (Aanat1 and Aanat2) and Hydroxyindole-O-methyltransferase (Hiomt) in any tropical fish. This study has identified two subtypes of Aanat (1 &2) as it was found in other teleost. The distribution of these enzymes were found in nine tissues (brain, pineal organ, retina, gut, liver, skeletal muscle, heart, kidney and ovary) which include both central and peripheral units. This finding is signifying the presence of melatonin bio-synthesizing machinery in all major tissues/organs of this tropical carp. High sequence similarities of these genes among teleost revealed a conserved pattern of evolution and the presence of melatonin bio-synthesising enzyme gene transcripts in all major tissues makes it a prominent candidate to be used as model for the chronobiological studies.

Daily and Seasonal Expression Profile of Serum Melatonin and Its Biosynthesizing Enzyme Genes (tph1, aanat1, aanat2, and hiomt) in Pineal Organ and Retina: A Study under Natural Environmental Conditions in a Tropical Carp, Catla catla

The tropical carp Catla catla is gaining importance for the studies of the impact of environmental changes on aquatic animals due to its surface dwelling habitat. To date, no information is available on the transcriptional profile of melatonin biosynthesizing enzyme genes in any tropical carp under either natural or artificial photothermal conditions in pineal and retina. The present study is an attempt to demonstrate the temporal pattern of expression of melatonin biosynthesizing enzyme genes, tryptophan hydroxylase 1 (tph1), arylalkylamine N-acetyltransferase (aanat1 and aanat2), and hydroxyindole-O-methyltransferase (hiomt) collectively and simultaneously in pineal organ and retina in tropical fish, C. catla, on a daily and seasonal basis under natural environmental conditions along with the serum melatonin levels. Depending upon the changes of the natural photothermal conditions, in four phases of an annual cycle, the variation and/or shifting of the rhythm parameters of different melatonin biosynthesizing enzyme genes in these two organs are different. Moreover, relative expression of these genes varies based on tissue and season. The serum melatonin levels correspond to the expression pattern of pineal aanat2 and hiomt. This finding indicates a possible organization of melatonin biosynthesizing enzyme genes with reproductive phases differently in these two photoreceptive organs for maintaining its physiological functions.