Subhash J. Jakhesara

High through put 16S rRNA gene-based pyrosequencing analysis of the fecal microbiota of high FCR and low FCR broiler growers

The performance of birds appears to vary among the flock of growing broilers which may in part be due to variation in their gut microbiota. In the view of poultry industry, it is desirable to minimise such variation. We investigated metagenomic profile of fecal bacteria in birds with high and low feed conversion ratio (FCR) to identify microbial community linked to low and high FCR by employing high throughput pyrosequencing of 16S rRNA genomic targets. Therefore feeding trial was investigated in order to identify fecal bacteria consistently linked with better feed conversion ratio in bird performance as measured by body weight gain. High-throughput 16S rRNA gene based pyrosequencing was used to provide a comparative analysis of fecal microbial diversity. The fecal microbial community of birds was predominated by Proteobacteria (48.04xa0% in high FCR and 49.98xa0% in low FCR), Firmicutes (26.17xa0% in high FCR and 36.23xa0% in low FCR), Bacteroidetes (18.62xa0% in high FCR and 11.66xa0% in low FCR), as well as unclassified bacteria (15.77xa0% in high FCR and 14.29xa0% in low FCR), suggesting that a large portion of fecal microbiota is novel and could be involved in currently unknown functions. The most prevalent bacterial classes in high FCR and low FCR were Gammaproteobacteria, Clostridia and Bacteroidia. However in low FCR birds Phascolarctobacterium, Faecalibacterium and Clostridium predominated among the Clostridia. In FCR comparison of fecal bacteria, about 36 genera were differentially abundant between high and low FCR birds. This information could be used to formulate effective strategies to improve feed efficiency and feed formulation for optimal gut health.

Milk microbiome signatures of subclinical mastitis-affected cattle analysed by shotgun sequencing

Aims:u2002 Metagenomic analysis of milk samples collected from Kankrej, Gir (Bos indicus) and crossbred (Bos taurusu2003×u2003B. indicus) cattle harbouring subclinical mastitis was carried out by next‐generation sequencing 454 GS‐FLX technology to elucidate the microbial community structure of cattle milk.

Metagenomic analysis of Surti buffalo (Bubalus bubalis) rumen: a preliminary study

The complex microbiome of the rumen functions as an effective system for the conversion of plant cell wall biomass to microbial proteins, short chain fatty acids and gases. In this study, metagenomic approaches were used to study the microbial populations and metabolic potential of the microbial community. DNA was extracted from Surti Buffalo rumen samples (four treatments diet) and sequenced separately using a 454 GS FLX Titanium system. We used comparative metagenomics to examine metabolic potential and phylogenetic composition from pyrosequence data generated in four samples, considering phylogenetic composition and metabolic potentials in the rumen may remarkably be different with respect to nutrient utilization. Assignment of metagenomic sequences to SEED categories of the Metagenome Rapid Annotation using Subsystem Technology (MG-RAST) server revealed a genetic profile characteristic of fermentation of carbohydrates in a high roughage diet. The distribution of phylotypes and environmental gene tags (EGTs) detected within each rumen sample were dominated by Bacteroidetes/Chlorobi, Firmicutes and Proteobacteria in all the samples. The results of this study could help to determine the role of rumen microbes and their enzymes in plant polysaccharide breakdown is fundamental to understanding digestion and maximising productivity in ruminant animals.

Mining of Ruminant Microbial Phytase (RPHY1) from Metagenomic Data of Mehsani Buffalo Breed: Identification, Gene Cloning, and Characterization

Phytases have been widely used as animal feed supplements to increase the availability of digestible phosphorus, especially in monogastric animals fed cereal grains. The present study describes the identification of a full-length phytase gene of Prevotella species present in Mehsani buffalo rumen. The gene, designated as RPHY1, consists of 1,251 bp and is expressed into protein with 417 amino acids. A homology search of the deduced amino acid sequence of the RPHY1 phytase gene in a nonredundant protein database showed that it shares 92% similarity with the histidine acid phosphatase domain. Subsequently, the RPHY1 gene was expressed using a pET32a expression vector in Escherichia coli BL21 and purified using a His60 Ni-NTA gravity column. The mass of the purified RPHY1 was estimated to be approximately 63 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal RPHY1 enzyme activity was observed at 55°C (pH 5) and exhibited good stability at 5°C and within the acidic pH range. Significant inhibition of RPHY1 activity was observed for Mg2+ and K+ metal ions, while Ca2+, Mn2+, and Na+ slightly inhibited enzyme activity. The RPHY1 phytase was susceptible to SDS, and it was highly stimulated in the presence of EDTA. Overall, the observed comparatively high enzyme activity levels and characteristics of the RPHY1 gene mined from rumen prove its promising candidature as a feed supplement enzyme in animal farming.

Differential expression of microRNAs associated with thermal stress in Frieswal ( Bos taurus x Bos indicus ) crossbred dairy cattle

Environmental temperature is one of the important abiotic factors that influence the normal physiological function and productive performance of dairy cattle. Temperature stress evokes complex responses that are essential for safeguarding of cellular integrity and animal health. Post-transcriptional regulation of gene expression by miRNA plays a key role cellular stress responses. The present study investigated the differential expression of miRNA in Frieswal (Holstein Friesianxa0×xa0Sahiwal) crossbred dairy cattle that are distinctly adapted to environmental temperature stress as they were evolved by using the temperate dairy breed Holstein Friesian. The results indicated that there was a significant variation in the physiological and biochemical indicators estimated under summer stress. The differential expression of miRNA was observed under heat stress when compared to the normal winter season. Out of the total 420 miRNAs, 65 were differentially expressed during peak summer temperatures. Most of these miRNAs were found to target heat shock responsive genes especially members of heat shock protein (HSP) family, and network analysis revealed most of them having stress-mediated effects on signaling mechanisms. Being greater in their expression profile during peak summer, bta-miR-2898 was chosen for reporter assay to identify its effect on the target HSPB8 (heat shock protein 22) gene in stressed bovine PBMC cell cultured model. Comprehensive understanding of the biological regulation of stress responsive mechanism is critical for developing approaches to reduce the production losses due to environmental heat stress in dairy cattle.

Transcriptomic comparison of primary bovine horn core carcinoma culture and parental tissue at early stage

Aim: Squamous cell carcinoma or SCC of horn in bovines (bovine horn core carcinoma) frequently observed in Bos indicus affecting almost 1% of cattle population. Freshly isolated primary epithelial cells may be closely related to the malignant epithelial cells of the tumor. Comparison of gene expression in between horn’s SCC tissue and its early passage primary culture using next generation sequencing was the aim of this study. Materials and Methods: Whole transcriptome sequencing of horn’s SCC tissue and its early passage cells using Ion Torrent PGM were done. Comparative expression and analysis of different genes and pathways related to cancer and biological processes associated with malignancy, proliferating capacity, differentiation, apoptosis, senescence, adhesion, cohesion, migration, invasion, angiogenesis, and metabolic pathways were identified. Results: Up-regulated genes in SCC of horn’s early passage cells were involved in transporter activity, catalytic activity, nucleic acid binding transcription factor activity, biogenesis, cellular processes, biological regulation and localization and the down-regulated genes mainly were involved in focal adhesion, extracellular matrix receptor interaction and spliceosome activity. Conclusion: The experiment revealed similar transcriptomic nature of horn’s SCC tissue and its early passage cells.

Complete genome sequence analysis of chicken astrovirus isolate from India

ObjectiveChicken astroviruses have been known to cause severe disease in chickens leading to increased mortality and “white chicks” condition. Here we aim to characterize the causative agent of visceral gout suspected for astrovirus infection in broiler breeder chickens.MethodsTotal RNA isolated from allantoic fluid of SPF embryo passaged with infected chicken sample was sequenced by whole genome shotgun sequencing using ion-torrent PGM platform. The sequence was analysed for the presence of coding and non-coding features, its similarity with reported isolates and epitope analysis of capsid structural protein.ResultsThe consensus length of 7513xa0bp genome sequence of Indian isolate of chicken astrovirus was obtained after assembly of 14,121 high quality reads. The genome was comprised of 13xa0bp 5′-UTR, three open reading frames (ORFs) including ORF1a encoding serine protease, ORF1b encoding RNA dependent RNA polymerase (RdRp) and ORF2 encoding capsid protein, and 298xa0bp of 3′-UTR which harboured two corona virus stem loop II like “s2m” motifs and a poly A stretch of 19 nucleotides. The genetic analysis of CAstV/INDIA/ANAND/2016 suggested highest sequence similarity of 86.94% with the chicken astrovirus isolate CAstV/GA2011 followed by 84.76% with CAstV/4175 and 74.48%% with CAstV/Poland/G059/2014 isolates. The capsid structural protein of CAstV/INDIA/ANAND/2016 showed 84.67% similarity with chicken astrovirus isolate CAstV/GA2011, 81.06% with CAstV/4175 and 41.18% with CAstV/Poland/G059/2014 isolates. However, the capsid protein sequence showed high degree of sequence identity at nucleotide level (98.64-99.32%) and at amino acids level (97.74–98.69%) with reported sequences of Indian isolates suggesting their common origin and limited sequence divergence. The epitope analysis by SVMTriP identified two unique epitopes in our isolate, seven shared epitopes among Indian isolates and two shared epitopes among all isolates except Poland isolate which carried all distinct epitopes.

Identification of novel SNPs in differentially expressed genes and its association with horn cancer of Bos indicus bullocks by next-generation sequencing

The use of polymorphic markers like SNPs promises to provide comprehensive tool for analysing genome and identifying genomic regions that contribute to cancer phenotype. Horn cancer is the most common cancer among Bos indicus animals. Increased expression of some genes due to polymorphisms increases risk of HC incidence. We successfully amplified 91 SNPs located in 69 genes in 52 samples, each of HC and HN. Equimolar concentration of amplicons from 69 PCR products of each sample was pooled and subjected to sequencing using Ion Torrent PGM. Data obtained were analysed using DNASTAR software package and case control analysis using SAS software. We found SNP present in BPIFA1 gene of B. indicus shows association with event of HC which reflects its potential to be a genetic marker. Bioinformatic analysis to detect structural and functional impact nsSNP of BPIFA1 added another layer of confirmation to our result. We successfully identified SNP associated with HC as well as demonstrated efficient approach for limited number of SNP discovery and validation in targeted genomics regions in large number of samples combining PCR amplification and Ion Torrent PGM sequencing which suits small-scale laboratories with limited budget.

Viral Metagenomics of chickens with respiratory infection using MG-RAST

Respiratory tract infections in poultry flocks lead to increased rate of mortality and thereby increase economic burden to the poultry industry. The aim of the study was to identify variety of known and unknown microbial organisms participating in the respiratory tract infections in poultry. Infected samples from 8 different poultry farms located in the Anand district of Gujarat, India were collected. Using Next Generation Sequencing (NGS) platform Ion Torrent PGM, approximately 1.1 giga-bases of sequences by metagenomics pipeline were obtained. To understand the community of bacterial as well as viral sequences involved in the infection, MG-RAST, an automated online based approach was used. The taxonomical classfication resulted in sequences with 78.91% of bacteria, 9.35% of eukaryota, 8.17% of viruses, 0.10% of archaea, 0.02% of unclassified sequences, 0.45% of other sequences and 2.99% were unannotated. While functional classification of sequences resulted in 22.15% of predicted proteins with known functions, 77.74% of predicted proteins with unknown function, and very negligible 0.01% of ribosomal RNA genes. The most abundant virus families observed were Podoviridae, Myoviridae and Siphoviridae belonging to the Caudovirales order. This study is the first approach for annotating metagenomics of poultry having respiratory infection using MG-RAST approach.

Metagenomic characterisation of ruminal bacterial diversity in buffaloes from birth to adulthood using 16S rRNA gene amplicon sequencing

Microbial colonisation in the forestomach of a ruminant is one of the most crucial factors in determining many of its physiological developments and digestive capabilities. The present study attempts to identify establishment pattern of microbes in relation to food, age and rumen development in the buffalo calves at every fortnight interval from birth to 6xa0months of age, followed by every month till animals became 1xa0year of age. Diversity study based on 16S rRNA gene sequencing identified rapidly changing bacterial population during initial 60xa0days of life, which got assemblage as rumen became physiologically mature with increasing age of animals. A lactate fermenting aerobic to facultative anaerobic genera found during initial 30xa0days of life were expeditiously replaced by strict anaerobic cellulolytic bacterial population with increasing age. The study confirms that initial colonisation mainly depends on the oral cavity and skin of the mother, followed by the surrounding environment and feed offered, which is reversed in order once animal gets older. Some of the well-described genera based on culture-dependent studies like Ruminococcus spp. were found to be in lesser proportion suggesting an additional role of other microbes or niche in cellulose degradation. We report the presence of Porphyromonas spp. and Mannheimia glucosidal for the first time in bovine infants.