Description of a neotype for platygaster macrophthalma Swainson, 1838 (= Ilisha megaloptera)

A neotype is described for Platygaster macrophthalma Swainson, 1838 (Pisces: Clupeidae) from the type locality, Visakhapatnam, India.     

Genomic Epidemiology Reconstructs the Introduction and Spread of Zika Virus in Central America and Mexico

1. Download high-res image (290KB)
2. Download full-size image

     

A tropical oviparous lizard, Calotes versicolor, exhibiting a potentially novel FMFM pattern of temperature-dependent sex determination

Among squamate reptiles, lizards exhibit an impressive array of sex-determining modes viz. genotypic sex determination, temperature-dependent sex determination, co-occurrence of both these and those that reproduce parthenogenetically. The oviparous lizard, Calotes versicolor, lacks heteromorphic sex chromosomes and there are no reports on homomorphic chromosomes. Earlier studies on this species presented little evidence to the sex-determining mechanism. Here we provide evidences for the potential role played by incubation temperature that has a significant effect (P < 0.01) on gonadal sex and sex ratio. The eggs were incubated at 14 different incubation temperatures. Interestingly, 100% males were produced at low (25.5 ± 0.5 ° C) as well as high (34 ± 0.5 ° C) incubation temperatures and 100% females were produced at low (23.5 ± 0.5 ° C) and high (31.5 ± 0.5 ° C) temperatures, clearly indicating the occurrence of TSD in this species. Sex ratios of individual clutches did not vary at any of the critical male-producing or female-producing temperatures within as well as across the seasons. However, clutch sex ratios were female- or male-biased at intermediate temperatures. Thermosensitive period occurred during the embryonic stages 30-33. Three pivotal temperatures operate producing 1:1 sex ratio. Histology of gonad and accessory reproductive structures provide additional evidence for TSD. The sex-determining pattern, observed for the first time in this species, that neither compares to Pattern I [Ia (MF) and Ib (FM)] nor to Pattern II (FMF), is being referred to as FMFM pattern of TSD. This novel FMFM pattern of sex ratio exhibited by C. versicolor may have an adaptive significance in maintaining sex ratio.     

Baculovirus-based genetic screen for antiapoptotic genes identifies a novel IAP

The prototype baculovirus, Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) expresses p35, a potent anti cell-death gene that promotes the propagation of the virus by blocking host cell apoptosis. Infection of insect Sf-21 cells with AcMNPV lacking p35 induces apoptosis. We have used this pro-apoptotic property of the p35 null virus to screen for genes encoding inhibitors of apoptosis that rescue cells infected with the p35 defective virus. We report here the identification of Tn-IAP1, a novel member of the IAP family of cell death inhibitors. Tn-IAP1 blocks cell death induced by p35 null AcMNPV, actinomycin D, and Drosophila cell-death inducers HID and GRIM. Given the conserved nature of the cell death pathway, this genetic screen can be used for rapid identification of novel inhibitors of apoptosis from diverse sources.     

Extracellular Polysaccharide Production by Thraustochytrid Protists

Four strains of marine stramenopilan protists, the thraustochytrids, were studied for their ability to produce extracellular polysaccharides (EPSs). Observations by light and scanning electron microscopy revealed the production of a matrix of EPS around groups of cells in stationary cultures. EPS in shake culture filtrates ranged from 0.3 to 1.1 g/L. EPS production, which was studied in greater detail in 2 isolates, SC-1 and CW1, increased with age of cultures, reaching a peak in the stationary phase. Anion exchange chromatography yielded a single fraction of the EPS of both species. The EPS contained 39% to 53% sugars, besides proteins, lipids, uronic acids, and sulfates. Molecular weight of the EPS produced by SC-1 was approximately 94 kDa, and that of CW1, 320 kDa. Glucose formed the major component in the EPS of both isolates—galactose, mannose, and arabinose being the other components. Cultures of both isolates survived air-drying up to a period of 96 hours, suggesting a role for EPS in preventing desiccation of cells.     

Whole Genome Sequencing and Analysis of Plant Growth Promoting Bacteria Isolated from the Rhizosphere of Plantation Crops Coconut,Cocoa and Arecanut

Coconut, cocoa and arecanut are commercial plantation crops that play a vital role in the Indian economy while sustaining the livelihood of more than 10 million Indians. According to 2012 Food and Agricultural organization''s report, India is the third largest producer of coconut and it dominates the production of arecanut worldwide. In this study, three Plant Growth Promoting Rhizobacteria (PGPR) from coconut (CPCRI-1), cocoa (CPCRI-2) and arecanut (CPCRI-3) characterized for the PGP activities have been sequenced. The draft genome sizes were 4.7 Mb (56% GC), 5.9 Mb (63.6% GC) and 5.1 Mb (54.8% GB) for CPCRI-1, CPCRI-2, CPCRI-3, respectively. These genomes encoded 4056 (CPCRI-1), 4637 (CPCRI-2) and 4286 (CPCRI-3) protein-coding genes. Phylogenetic analysis revealed that both CPCRI-1 and CPCRI-3 belonged to Enterobacteriaceae family, while, CPCRI-2 was a Pseudomonadaceae family member. Functional annotation of the genes predicted that all three bacteria encoded genes needed for mineral phosphate solubilization, siderophores, acetoin, butanediol, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, chitinase, phenazine, 4-hydroxybenzoate, trehalose and quorum sensing molecules supportive of the plant growth promoting traits observed in the course of their isolation and characterization. Additionally, in all the three CPCRI PGPRs, we identified genes involved in synthesis of hydrogen sulfide (H₂S), which recently has been proposed to aid plant growth. The PGPRs also carried genes for central carbohydrate metabolism indicating that the bacteria can efficiently utilize the root exudates and other organic materials as energy source. Genes for production of peroxidases, catalases and superoxide dismutases that confer resistance to oxidative stresses in plants were identified. Besides these, genes for heat shock tolerance, cold shock tolerance and glycine-betaine production that enable bacteria to survive abiotic stress were also identified.     

Prediction of estrus cyclicity in Asian elephants (Elephas maximus) through estimation of fecal progesterone metabolite: development of an enzyme-linked immuno-sorbent assay

Asian elephants (Elephas maximus), prominent “flagship species”, are listed under the category of endangered species (EN - A2c, ver. 3.1; IUCN Red List 2009) and there is a need for their conservation. This requires understanding demographic and reproductive dynamics of the species. Monitoring reproductive status of any species is traditionally being carried out through invasive blood sampling and this is restrictive for large animals such as wild or semi-captive elephants due to legal, ethical, and practical reasons. Hence, there is a need for a non-invasive technique to assess reproductive cyclicity profiles of elephants, which will help in the species’ conservation strategies. In this study, we developed an indirect competitive enzyme linked immuno-sorbent assay (ELISA) to estimate the concentration of one of the progesterone-metabolites i.e., allopregnanolone (5α-P-3OH) in fecal samples of Asian elephants. We validated the assay which had a sensitivity of 0.25 μM at 90% binding with an EC₅₀ value of 1.37 μM. Using female elephants, kept under semi-captive conditions in the forest camps of Mudumalai Wildlife Sanctuary, Tamil Nadu and Bandipur National Park, Karnataka, India, we measured fecal progesterone-metabolite (5α-P-3OH) concentrations in six animals and showed their clear correlation with those of serum progesterone, measured by a standard radio-immuno assay. Statistical analyses using a Linear Mixed Effect model showed a positive correlation (P < 0.1) between the profiles of fecal 5α-P-3OH (range: 0.5-10 μg/g) and serum progesterone (range: 0.1-1.8 ng/mL). Therefore, our studies show, for the first time, that the fecal progesterone-metabolite assay could be exploited to predict estrus cyclicity and to potentially assess the reproductive status of captive and free-ranging female Asian elephants, thereby helping to plan their breeding strategy.     

Polydactylus konadaensis Mishra and Krishnan, 1993, a junior synonym of Filimanus xanthonema (Valenciennes in Cuvier and Valenciennes, 1831) (Perciformes: Polynemidae)

Polydactylus konadaensis Mishra and Krishnan, 1993 was described on the basis of two specimens from Konada, Andhra Pradesh, east coast of India. Although the new species was placed in the genus Polydactylus, our examination of the type specimens of the species showed them to represent a species of Filimanus. Furthermore, the characters of those specimens were consistent with those of the lectotype, paralectotype, and other specimens of F. xanthonema (Valenciennes in Cuvier and Valenciennes, 1831). Accordingly, Polydactylus konadaensis is herein regarded as a junior synonym of F. xanthonema. Received: July 2, 2000 / Revised: November 2, 2000 / Accepted: January 12, 2001