Project description:Use of genomic DNA as an indirect reference for identifying gender associated transcripts in morphologically identical, but chromosomally distinct, Schistosoma mansoni cercariae
Project description:Schistosoma mansoni is a dioecious species, that is, it has two differentiated sexes. Interestingly, this sexual species evolved from a hermaphrodite ancestor. Indeed, most Platyhelminthes are hermaphrodites. Here we characterize the microRNAs of S. mansoni and quantify their differential expression between males and females. Mice were infected with Schistosoma mansoni 1-2 weeks prior to dissection. RNA from two independent samples were extracted and sequenced with Illumina MiSeq technology and AB SOLiD 4 technology. Reads were mapped to the reference genome and microRNA detected and analyzed.
Project description:Chinese and Philippine strains of the blood fluke Schistosoma japonicum present clear and distinctive phenotypes in areas of fecundity, pathology, drug sensitivity and immunology. Despite these differences large scale sequencing efforts have focused solely on Chinese mainland strain of the parasite. We have undertaken a comparative genomic hybridisation (CGH) approach to highlight some of the structural differences in the genome of two of the major geographical isolates of S. japonicum. We identified seven distinct regions of the S. japonicum genome that present differential CGH between Chinese and Philippine strains of the blood fluke Schistosoma japonicum, representing either deletion or duplication regions in the Philippine strain. Within these regions, genes that may be related to phenotypical differences are identified and discussed.
Project description:High throughput sequencing of different life cycle stages of Schistosoma mansoni to identify loci that are methylated and use the information to focus on regions of biological relevance related to development and control of disease.
Project description:Venomous animals have traditionally been studied from a proteomic (but also transcriptomic) perspective, often overlooking the study of venom from a genomic point of view until recently. The rise of genomics has led to an increase in the number of reference genomes for non-model organisms, including venomous taxa, enabling new questions on venom evolution from a genomic context. Although venomous snakes are the fundamental model system in venom research, the number of high-quality reference genomes in the group remains limited. In this study, we present a high-quality chromosome-level reference genome for the Arabian horned viper (Cerastes gasperettii), a highly venomous snake native to the Arabian Peninsula. Our highly-contiguous genome allowed us to explore macrochromosomal rearrangements within the Viperidae family, as well as across squamate reptile evolution. Furthermore, we identified a total of ten different toxins conforming the venom’s core, in line with our proteomic results. We also compared microsyntenic changes in the main toxin gene clusters with those of other venomous snake species, highlighting the pivotal role of gene duplication and loss in the emergence and diversification of the two main toxin families for Cerastes gasperettii. Using Illumina data, we reconstructed the demographic history and genome-wide diversity of the species, revealing how historical aridity likely drove population expansions. Finally, this study highlights the importance of using long-read sequencing as well as chromosome-level reference genomes to disentangle the origin and diversification of toxin families in venomous species.