Ayan Mukherjee

Electrospun polycaprolactone/ZnO nanocomposite membranes as biomaterials with antibacterial and cell adhesion properties

In the present study we have investigated the effect of zinc oxide (ZnO) nanoparticles on the fiber diameter, fiber morphology, antibacterial activity, and enhanced cell proliferation of the electrospun polycaprolactone (PCL) non-woven membrane. The effect of the ZnO nanoparticle concentration on the fiber diameter and fiber morphology was investigated using a scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FT-IR) analysis was carried out to determine the nature of the interaction between the PCL and the ZnO nanoparticles. We also investigated the mechanical stability and antibacterial activity of the fabricated material. Interestingly, the membranes with ZnO nanoparticles showed enhanced mechanical stability, antibacterial properties, fibroblast proliferation, and improved metabolic activity of the cells. Further, this is the first report regarding the ability of a biomaterial containing ZnO nanoparticles to enhance cell proliferation.

Polymorphism of BMPR1B, BMP15 and GDF9 fecundity genes in prolific Garole sheep

Mutation studies in different prolific sheep breeds have shown that the transforming growth factor beta super family ligands viz. the growth differentiation factor 9 (GDF9/FecG), bone morphogenetic protein 15 (BMP15/FecX) and associated type I receptors, bone morphogenetic protein receptor (BMPR1B/FecB), are major determinant of ovulation rate and consequent increase in litter size. The Garole sheep is a highly prolific sheep breed of India. Characterization of fecundity genes in these animals could substantially improvise the breeding programme in these animals as well as other sheep breeds of the region. The present study was therefore designed with the objective of polymorphism study of fecundity genes in these prolific microsheep. A total of 11 point mutations were detected by polymerase chain reaction (PCR)-based method. A competitive technique called tetra-primer amplification refractory mutation system-PCR was adapted to type a total of ten points of two ovine fecundity genes (GDF9 and BMP15). The FecB locus of the BMPR1B gene and G1 locus of GDF9 gene were found to be polymorphic. In FecB locus, two genotypes, wild type (FecB+) and mutant (FecBB), were detected with allele frequencies of 0.39 and 0.61, respectively. At G1 locus, two genotypes, mutant (A) and wild types (G) were detected with allele frequencies of 0.18 and 0.82, respectively. This study reports Garole sheep as the fourth sheep breed after Belclare/Cambridge, Lacaune and Small-tailed Han sheep, where coexisting polymorphism has been found in two different fecundity genes (BMPRIB and GDF9 genes).

Cyclotron resonance heating systems for SST-1

RF systems in the ion cyclotron resonance frequency (ICRF) range and electron cyclotron resonance frequency (ECRF) range are in an advanced stage of commissioning, to carry out pre-ionization, breakdown, heating and current drive experiments on the steady-state superconducting tokamak SST-1. Initially the 1.5 MW continuous wave ICRF system would be used to heat the SST-1 plasma to 1.0 keV during a pulse length of 1000 s. For different heating scenarios at 1.5 and 3.0 T, a wide band of operating frequencies (20–92 MHz) is required. To meet this requirement two CW 1.5 MW rf generators are being developed in-house. A pressurized as well as vacuum transmission line and launcher for the SST-1–ICRF system has been commissioned and tested successfully. A gyrotron for the 82.6 GHz ECRF system has been tested for a 200 kW/1000 s operation on a water dummy load with 17% duty cycle. High power tests of the transmission line have been carried out and the burn pattern at the exit of transmission line shows a gaussian nature. Launchers used to focus and steer the microwave beam in plasma volume are characterized by a low power microwave source and tested for UHV compatibility. Long pulse operation has been made feasible by actively cooling both the systems. In this paper detailed test results and the present status of both the systems are reported.

POLYMORPHISM OF FECUNDITY GENES (FECB, FECX, AND FECG) IN THE INDIAN BONPALA SHEEP

The present study was designed for screening polymorphism of known fecundity genes in prolific Indian Bonpala sheep. Employing tetra-primer amplification refractory mutation system PCR, 11-point mutations of BMP1B, BMP15, and GDF9 genes of 97 Bonpala ewes were genotyped. The FecB locus of the BMPR1B gene and two loci (G1 and G4) of GDF9 gene were found to be polymorphic. In FecB locus, three genotypes, namely, wild type (Fec++, 0.02), heterozygous (FecB+, 0.23), and mutant (FecBB, 0.75) were detected. At G1 locus of GDF9 gene, three genotypes, namely, wild type (GG, 0.89), heterozygous (GA, 0.10), and mutant (AA, 0.01) were detected. At G4 locus of GDF9 gene, three genotypes, namely, wild type (AA, 0.01), heterozygous (AG, 0.14), and mutant (GG, 0.85) were detected. Statistically no significant correlation of polymorphism of FecB, G1, and G4 loci and litter size was found in this breed. All five loci of BMP15 and three loci of GDF 9 genes were monomorphic. This study reports Bonpala sheep as the first sheep breed where concurrent polymorphism at three important loci (FecB, G1, and G4) of two different fecundity genes (BMPR1B and GDF9) has been found.

Absolute copy number differences of Y chromosomal genes between crossbred (Bos taurus × Bos indicus) and Indicine bulls

BackgroundThe Y chromosome in mammal is paternally inherited and harbors genes related to male fertility and spermatogenesis. The unique intra-chromosomal recombination pattern of Y chromosome and morphological difference of this chromosome between Bos taurus and Bos indicus make it an ideal model for studying structural variation, especially in crossbred (Bos taurus × Bos indicus) bulls. Copy Number Variation (CNV) is a type of genomic structural variation that gives information complementary to SNP data. The purpose of this study was to find out copy number differences of four Y chromosomal spermatogenesis-related candidate genes in genomic DNA of crossbred and purebred Indicine bulls.ResultFour Y chromosomal candidate genes of spermatogenesis namely, sex determining gene on Y chromosome (SRY), DEAD box polypeptide 3-Y chromosome (DDX3Y), Ubiquitin specific peptidase 9, Y-linked (USP9Y), testis-specific protein on Y chromosome (TSPY) were evaluated. Absolute copy numbers of Y chromosomal genes were determined by standard curve-based quantitative real time PCR. Copy numbers of SRY and TSPY genes per unit amount of genomic DNA are higher in crossbred than Indicine bulls. However, no difference was observed in DDX3Y and USP9Y gene copy numbers between two groups.ConclusionThe present study demonstrates that the structural organization of Y chromosomes differs between crossbred and Indicine bulls which are reproductively healthy as observed from analysis of semen attributes. The absolute copy numbers of SRY and TSPY genes in unit mass of genomic DNA of crossbred bulls are significantly higher than Indicine bulls. No alteration in absolute copies of DDX3Y and USP9Y gene was found between the genome of crossbred and Indicine bulls. This study suggests that the DDX3Y and USP9Y are likely to be single copy genes in the genome of crossbred and Indicine bulls and variation in Y chromosome length between crossbred and Indicine bulls may be due to the copy number variation of SRY gene and TSPY array.

Stability of nano-sized permethrin in its colloidal state and its effect on the physiological and biochemical profile of Culex tritaeniorhynchus larvae

The occurrence of pesticidal pollution in the environment and the resistance in the mosquito species makes an urge for the safer and an effective pesticide. Permethrin, a poorly water-soluble pyrethroid pesticide, was formulated into a hydrodispersible nanopowder through rapid solvent evaporation of pesticide-loaded oil in water microemulsion. Stability studies confirmed that the nanopermethrin dispersion was stable in paddy field water for 5 days with the mean particle sizes of 175.3 ± 0.75 nm and zeta potential of -30.6 ± 0.62 mV. The instability rate of the nanopermethrin particles was greater in alkaline (pH 10) medium when compared with the neutral (pH 7) and acidic (pH 4) dispersion medium. The colloidal dispersion at 45°C was found to be less stable compared with the dispersions at 25 and 5°C. The 12- and 24-h lethal indices (LC50) for nanopermethrin were found to be 0.057 and 0.014 mg l-1, respectively. These results were corroborative with the severity of damages observed in the mosquito larvae manifested in epithelial cells and the evacuation of the midgut contents. Further, the results were substantiated by the decrease in cellular biomolecules and biomarker enzyme activity in nanopermethrin treated larvae when compared to bulk and control treatment.

Ion cyclotron resonance heating system on Aditya

An ion cyclotron resonance heating (ICRH) system has been designed, fabricated indigenously and commissioned on Tokamak Aditya. The system has been commissioned to operate between 20.0 and 47.0 MHz at a maximum power of 200 kW continuous wave (CW). Duration of 500 ms is sufficient for operation on Aditya, however, the same system feeds the final stage of the 1.5 MW ICRH system being prepared for the steady-state superconducting tokamak (SST-1) for a duration of 1000 s. Radio frequency (RF) power (225 kW) has been generated and successfully tested on a dummy load for 100 s at 30.0 MHz. Lower powers have been coupled to Aditya in a breakdown experiment. We describe the system in detail in this work.

Generation of parthenogenetic goat blastocysts: effects of different activation methods and culture media

The present study was carried out to investigate the effects of different activation methods and culture media on the in vitro development of parthenogenetic goat blastocysts. Calcium (Ca2+) ionophore, ethanol or a combination of the two, used as activating reagents, and embryo development medium (EDM), modified Charles Rosenkrans (mCR2a) medium and research vitro cleave (RVCL) medium were used to evaluate the developmental competence of goat blastocysts. Quantitative expression of apoptosis, stress and developmental competence-related genes were analysed in different stages of embryos. In RVCL medium, the cleavage rate of Ca2+ ionophore-treated oocytes (79.61 ± 0.86) was significantly (P < 0.05) higher than in ethanol (74.90 ± 1.51) or in the combination of both Ca2+ ionophore and ethanol. In mCR2a or EDM, hatched blastocyst production rate of Ca2+ ionophore-treated oocytes (8.33 ± 1.44) was significantly higher than in ethanol (6.46 ± 0.11) or in the combined treatment (6.70 ± 0.24). In ethanol, the cleavage, blastocyst and hatched blastocyst production rates in RVCL medium (74.90 ± 1.51, 18.30 ± 1.52 and 8.24 ± 0.15, respectively) were significantly higher than in EDM (67.81 ± 3.21, 14.59 ± 0.27 and 5.59 ± 0.42) or mCR2a medium (65.09 ± 1.57, 15.36 ± 0.52 and 6.46 ± 0.11). The expression of BAX, Oct-4 and GlUT1 transcripts increased gradually from 2-cell stage to blastocyst-stage embryos, whereas the transcript levels of Bcl-2 and MnSOD were significantly lower in blastocysts. In addition, different activation methods and culture media had little effect on the pattern of variation and relative abundance of the above genes in different stages of parthenogenetic activated goat embryos. In conclusion, Ca2+ ionophore as the activating agent, and RVCL as the culture medium are better than other tested options for development of parthenogenetic activated goat blastocysts.

Comparison of Copy Number of HSF Genes in Two Buffalo Genomes.

ABSTRACT The copy number variation (CNV) is the number of copies of a particular gene in the genotype of an individual. Recent evidences show that the CNVs can vary in frequency and occurrence between breeds. These variations reportedly allowed different breeds to adapt to different environments. As copy number variations follow Mendelian pattern of inheritance, identification and distribution of these variants between populations can be used to infer the evolutionary history of the species. In this study, we have examined the absolute copy number of four Heat shock factor genes viz. HSF-1, 2, 4, and 5 in two different breeds of buffalo species using real-time PCR. Here, we report that the absolute copy number of HSF2 varies between the two breeds. In contrast no significant difference was observed in the copy number for HSF-1, 4, and 5 between the two breeds. Our results provide evidence for the presence of breed specific differences in HSF2 genomic copy number. This seems to be the first step in delineating the genetic factors underlying environmental adaptation between the two breeds. Nevertheless, a more detailed study is needed to characterize the functional consequence of this variation.

Prediction of Structure and Functions from Full Length Coding Sequence of SRY Gene in Crossbred and Indicine Bulls

Sex-determining Region on Y chromosome (SRY) is testis determining factor in mammalian species. It encodes a protein that possess high mobility group (HMG) DNA-binding domain and acts as an architectural transcription factor. Mutation in this gene causes sex-reversal in many mammalian species. Detailed structure and exact biological functions of this protein in bovine species are not known. In the present study the full length coding sequences of the gene from crosssbred and indicine bulls were amplified, translated in silico and 3D model of the protein were predicted from the amino acid sequences. Predicted structure-activity relationship of the protein states that the protein is subcellular, essential, N-glycosylated in nature and is involved in sex determination and neuroendocrine functioning in central and peripheral nervous systems. The proteins have also plausible role in RNA metabolism, transition-metal and calmodulin binding. Overall this structural and functional information about the protein in bovine species will reinforce the understanding of domain-specific role of this protein and development of diagnostics for sex-determination in bovine species.