Browsing by Author "Young, Neil D."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Chromosome-level genome of Schistosoma haematobium underpins genome-wide explorations of molecular variation
    (Public Library of Science, 2022) Stroehlein, Andreas J.; Korhonen, Pasi K.; Lee, V. Vern; Ralph, Stuart A.; Mentink-Kane, Margaret; You, Hong; McManus, Donald P.; Tchuenté, Louis-Albert Tchuem; Stothard, J. Russell; Kaur, Parwinder; Dudchenko, Olga; Aiden, Erez Lieberman; Yang, Bicheng; Yang, Huanming; Emery, Aidan M.; Webster, Bonnie L.; Brindley, Paul J.; Rollinson, David; Chang, Bill C.H.; Gasser, Robin B.; Young, Neil D.; Center for Theoretical Biological Physics
    Urogenital schistosomiasis is caused by the blood fluke Schistosoma haematobium and is one of the most neglected tropical diseases worldwide, afflicting > 100 million people. It is characterised by granulomata, fibrosis and calcification in urogenital tissues, and can lead to increased susceptibility to HIV/AIDS and squamous cell carcinoma of the bladder. To complement available treatment programs and break the transmission of disease, sound knowledge and understanding of the biology and ecology of S. haematobium is required. Hybridisation/introgression events and molecular variation among members of the S. haematobium-group might effect important biological and/or disease traits as well as the morbidity of disease and the effectiveness of control programs including mass drug administration. Here we report the first chromosome-contiguous genome for a well-defined laboratory line of this blood fluke. An exploration of this genome using transcriptomic data for all key developmental stages allowed us to refine gene models (including non-coding elements) and annotations, discover ‘new’ genes and transcription profiles for these stages, likely linked to development and/or pathogenesis. Molecular variation within S. haematobium among some geographical locations in Africa revealed unique genomic ‘signatures’ that matched species other than S. haematobium, indicating the occurrence of introgression events. The present reference genome (designated Shae.V3) and the findings from this study solidly underpin future functional genomic and molecular investigations of S. haematobium and accelerate systematic, large-scale population genomics investigations, with a focus on improved and sustained control of urogenital schistosomiasis.
  • Thumbnail Image
    Item
    Differences in transcription between free-living and CO2-activated third-stage larvae ofﾠHaemonchus contortus
    (BioMed Central, 2010) Cantacessi, Cinzia; Campbell, Bronwyn E.; Young, Neil D.; Jex, Aaron R.; Hall, Ross S.; Presidente, Paul J.A.; Zawadzki, Jodi L.; Zhong, Weiwei; Aleman-Meza, Boanerges; Loukas, Alex; Sternberg, Paul W.; Gasser, Robin B.
    Background: The disease caused by Haemonchus contortus, a blood-feeding nematode of small ruminants, is of major economic importance worldwide. The infective third-stage larva (L3) of this gastric nematode is enclosed in a cuticle (sheath) and, once ingested with herbage by the host, undergoes an exsheathment process that marks the transition from the free-living (L3) to the parasitic (xL3) stage. This study explored changes in gene transcription associated with this transition and predicted, based on comparative analysis, functional roles for key transcripts in the metabolic pathways linked to larval development. Results: Totals of 101,305 (L3) and 105,553 (xL3) expressed sequence tags (ESTs) were determined using 454 sequencing technology, and then assembled and annotated; the most abundant transcripts encoded transthyretin-like, calcium-binding EF-hand, NAD(P)-binding and nucleotide-binding proteins as well as homologues of Ancylostoma -secreted proteins (ASPs). Using an in silico -subtractive analysis, 560 and 685 sequences were shown to be uniquely represented in the L3 and xL3 stages, respectively; the transcripts encoded ribosomal proteins, collagens and elongation factors (in L3), and mainly peptidases and other enzymes of amino acid catabolism (in xL3). Caenorhabditis elegans orthologues of transcripts that were uniquely transcribed in each L3 and xL3 were predicted to interact with a total of 535 other genes, all of which were involved in embryonic development. Conclusion: The present study indicated that some key transcriptional alterations taking place during the transition from the L3 to the xL3 stage of H. contortus involve genes predicted to be linked to the development of neuronal tissue (L3 and xL3), formation of the cuticle (L3) and digestion of host haemoglobin (xL3). Future efforts using next-generation sequencing and bioinformatic technologies should provide the efficiency and depth of coverage required for the determination of the complete transcriptomes of different developmental stages and/or tissues of H. contortus as well as the genome of this important parasitic nematode. Such advances should lead to a significantly improved understanding of the molecular biology of H. contortus and, from an applied perspective, to novel methods of intervention.