Publications by authors named "Siddharth Jayaraman"

Background: Water buffalo is a cornerstone livestock species in many low- and middle-income countries, yet major gaps persist in its genomic characterization-complicated by the divergent karyotypes of its two subspecies (swamp and river). Such genomic complexity makes water buffalo a particularly good candidate for the use of graph genomics, which can capture variation missed by linear reference approaches. However, the utility of this approach to improve water buffalo has been largely unexplored.

View Article and Find Full Text PDF

The African buffalo (Syncerus caffer) is a wild bovid with a historical distribution across much of sub-Saharan Africa. Genomic analysis can provide insights into the evolutionary history of the species, and the key selective pressures shaping populations, including assessment of population level differentiation, population fragmentation, and population genetic structure. In this study we generated the highest quality de novo genome assembly (2.

View Article and Find Full Text PDF

Mucosal-associated invariant T (MAIT) cells are a subset of unconventional T cells that recognize small molecule metabolites presented by major histocompatibility complex class I related protein 1 (MR1), via an αβ T cell receptor (TCR). MAIT TCRs feature an essentially invariant TCR α-chain, which is highly conserved between mammals. Similarly, MR1 is the most highly conserved major histocompatibility complex-I-like molecule.

View Article and Find Full Text PDF

For the first time we have defined naïve, central memory, effector memory and differentiated effector porcine CD8 T cells and analyzed their distribution in lymphoid and respiratory tissues after influenza infection or immunization, using peptide-MHC tetramers of three influenza nucleoprotein (NP) epitopes. The hierarchy of response to the three epitopes changes during the response in different tissues. Most NP-specific CD8 T cells in broncho-alveolar lavage (BAL) and lung are tissue resident memory cells (TRM) that express CD69 and downregulate CD45RA and CCR7.

View Article and Find Full Text PDF

East Coast fever (ECF) in cattle is caused by the Apicomplexan protozoan parasite , transmitted by the three-host tick . The African buffalo () is the natural host for but does not suffer disease, whereas ECF is often fatal in cattle. The genetic relationship between populations circulating in cattle and buffalo is poorly understood, and has not been studied in sympatric buffalo and cattle.

View Article and Find Full Text PDF
Article Synopsis
  • Animal African Trypanosomiasis (AAT) is a serious livestock disease in sub-Saharan Africa caused mainly by the parasite Trypanosoma congolense, which is less understood than the related T. brucei.
  • Researchers utilized omics technologies and genetic tools to analyze the metabolism of T. congolense, finding that it relies heavily on glycolysis but has a slower glucose uptake and different metabolic byproducts compared to T. brucei.
  • The study revealed that while T. congolense is sensitive to certain metabolic inhibitors, it shows resistance to fatty acid synthesis inhibitors, indicating significant metabolic differences between the two parasites.
View Article and Find Full Text PDF
Article Synopsis
  • Trypanosoma congolense is a major cause of livestock trypanosomiasis in Africa, leading to significant economic loss and food security issues for developing countries.
  • A study induced stable resistance to the drug diminazene in a T. congolense strain, with no observed cross-resistance to other potential treatments, highlighting the complexity of drug resistance.
  • Findings indicate that diminazene uptake involves several low affinity mechanisms, including folate transporters, and resistance correlates with a decrease in mitochondrial membrane potential, though the exact cause of resistance remains unclear.
View Article and Find Full Text PDF

Mucosal-associated invariant T (MAIT) cells are a population of innate-like T cells that utilize a semi-invariant T cell receptor (TCR) α chain and are restricted by the highly conserved antigen presenting molecule MR1. MR1 presents microbial riboflavin biosynthesis derived metabolites produced by bacteria and fungi. Consistent with their ability to sense ligands derived from bacterial sources, MAIT cells have been associated with the immune response to a variety of bacterial infections, such as .

View Article and Find Full Text PDF

More people globally depend on the water buffalo than any other domesticated species, and as the most closely related domesticated species to cattle they can provide important insights into the shared evolutionary basis of domestication. Here, we sequence the genomes of 79 water buffalo across seven breeds and compare patterns of between breed selective sweeps with those seen for 294 cattle genomes representing 13 global breeds. The genomic regions under selection between cattle breeds significantly overlap regions linked to stature in human genetic studies, with a disproportionate number of these loci also shown to be under selection between water buffalo breeds.

View Article and Find Full Text PDF
Article Synopsis
  • Antigenic variation helps pathogens like Trypanosoma brucei avoid the immune response by using a diverse array of variant surface glycoprotein (VSG) genes, with about 2,000 different genes available for this purpose.!* -
  • Using long read sequencing on VSG amplicons from infected mice, researchers discovered significant diversity in VSG expression, with 449 unique VSGs detected and a notable increase in the number of expressed VSGs over time, especially peaking at day 10 post-infection.!* -
  • The study also introduced innovative methods for analyzing VSG expression patterns, revealing complex hierarchical expression and identifying mosaic VSG formation earlier than previously documented, showcasing the effectiveness
View Article and Find Full Text PDF

Human and animal African trypanosomiasis (HAT & AAT, respectively) remain a significant health and economic issue across much of sub-Saharan Africa. Effective control of AAT and potential eradication of HAT requires affordable, sensitive and specific diagnostic tests that can be used in the field. Small RNAs in the blood or serum are attractive disease biomarkers due to their stability, accessibility and available technologies for detection.

View Article and Find Full Text PDF

Cattle are an economically important domestic animal species. In vitro 2D cultures of intestinal epithelial cells or epithelial cell lines have been widely used to study cell function and host-pathogen interactions in the bovine intestine. However, these cultures lack the cellular diversity encountered in the intestinal epithelium, and the physiological relevance of monocultures of transformed cell lines is uncertain.

View Article and Find Full Text PDF

Transcriptional reprogramming is integral to effective plant defense. Pathogen effectors act transcriptionally and posttranscriptionally to suppress defense responses. A major challenge to understanding disease and defense responses is discriminating between transcriptional reprogramming associated with microbial-associated molecular pattern (MAMP)-triggered immunity (MTI) and that orchestrated by effectors.

View Article and Find Full Text PDF

Pathogens target phytohormone signalling pathways to promote disease. Plants deploy salicylic acid (SA)-mediated defences against biotrophs. Pathogens antagonize SA immunity by activating jasmonate signalling, for example Pseudomonas syringae pv.

View Article and Find Full Text PDF

Microbe associated molecular pattern (MAMP) receptors in plants recognize MAMPs and activate basal defences; however a complete understanding of the molecular and physiological mechanisms conferring immunity remains elusive. Pathogens suppress active defence in plants through the combined action of effector proteins. Here we show that the chloroplast is a key component of early immune responses.

View Article and Find Full Text PDF