A r t i c l e sThe dog tapeworm E. granulosus is one of a group of medically important parasitic helminths of the family Taeniidae (Platyhelminthes; Cestoda; Cyclophyllidea) that infect at least 50 million people globally 1 . Its life cycle involves two mammals, including an intermediate host, usually a domestic or wild ungulate (humans are accidental intermediate hosts) and a canine-definitive host, such as the domestic dog. The larval (metacestode) stage causes hydatidosis (cystic hydatid disease; cystic echinococcosis), a chronic cyst-forming disease in the intermediate (human) host. Currently, up to 3 million people are infected with E. granulosus 2,3 , and, in some areas, 10% of the population has detectable hydatid cysts by abdominal ultrasound and chest X-ray 4,5 .E. granulosus has no gut, circulatory or respiratory organs. It is monoecious, producing diploid eggs that give rise to ovoid embryos, the oncospheres. Strobilization is a notable feature of cestode biology, whereby proglottids bud distally from the anterior scolex, resulting in the production of tandem reproductive units exhibiting increasing degrees of development. A unique characteristic of the larvae (protoscoleces, PSCs) within the hydatid cyst is an ability to develop bidirectionally into an adult worm in the dog gastrointestinal tract or into a secondary hydatid cyst in the intermediate (human) host, a process triggered by bile acids 6 . Another distinct feature of E. granulosus is its capacity to infect and adapt to a large number of mammalian species as intermediate hosts, which has contributed to its cosmopolitan global distribution.Here we report the sequence and analysis of the E. granulosus genome. Comprising nine pairs of chromosomes 7 , it is one of the first cestode genomes to be sequenced and complements the recent publication by Tsai et al. 8 of a high-quality genome for Echinococcus multilocularis (the cause of alveolar echinococcosis), together with draft genomes of three other tapeworm species including E. granulosus. Our study provides insights into the biology, development, differentiation, evolution and host interaction of E. granulosus and has identified a range of drug and vaccine targets that can facilitate the development of new intervention tools for hydatid treatment and control. Cystic echinococcosis (hydatid disease), caused by the tapeworm E. granulosus, is responsible for considerable human morbidity and mortality. This cosmopolitan disease is difficult to diagnose, treat and control. We present a draft genomic sequence for the worm comprising 151.6 Mb encoding 11,325 genes. Comparisons with the genome sequences from other taxa show that E. granulosus has acquired a spectrum of genes, including the EgAgB family, whose products are secreted by the parasite to interact and redirect host immune responses. We also find that genes in bile salt pathways may control the bidirectional development of E. granulosus, and sequence differences in the calcium channel subunit EgCa v b 1 may be associated with praziquantel sens...
Introduction: Gut microbiome affecting the responses to immune checkpoint inhibitors against advanced NSCLC has been investigated in the Western population. However, considering pre-existing genetic and gut microbiota variation, the relevance remains unknown in the East-Asian NSCLC population. This study is designed to explore the relationship between gut microbiome and clinical outcomes in Chinese patients with NSCLC who have received treatment using an anti-programmed death 1 (PD-1) blockade. Methods: Thirty-seven patients with advanced NSCLC receiving treatment with nivolumab were enrolled in CheckMate 078 (NCT02613507) and CheckMate 870 (NCT03195491). Fecal samples were collected at the starting point, when patients received nivolumab, at clinical evaluation, and when disease progression was noted. 16S ribosome RNA gene sequencing was applied to assess gut microbiota profiles. Peripheral immune signatures were determined by multicolor flow cytometry in parallel.
Of the two cultivated species of allopolyploid cotton, Gossypium barbadense produces extra-long fibers for the production of superior textiles. We sequenced its genome (AD)2 and performed a comparative analysis. We identified three bursts of retrotransposons from 20 million years ago (Mya) and a genome-wide uneven pseudogenization peak at 11–20 Mya, which likely contributed to genomic divergences. Among the 2,483 genes preferentially expressed in fiber, a cell elongation regulator, PRE1, is strikingly At biased and fiber specific, echoing the A-genome origin of spinnable fiber. The expansion of the PRE members implies a genetic factor that underlies fiber elongation. Mature cotton fiber consists of nearly pure cellulose. G. barbadense and G. hirsutum contain 29 and 30 cellulose synthase (CesA) genes, respectively; whereas most of these genes (>25) are expressed in fiber, genes for secondary cell wall biosynthesis exhibited a delayed and higher degree of up-regulation in G. barbadense compared with G. hirsutum, conferring an extended elongation stage and highly active secondary wall deposition during extra-long fiber development. The rapid diversification of sesquiterpene synthase genes in the gossypol pathway exemplifies the chemical diversity of lineage-specific secondary metabolites. The G. barbadense genome advances our understanding of allopolyploidy, which will help improve cotton fiber quality.
M. tuberculosis population within patients exhibited considerable genetic diversity, which underwent selections for most fit resistant mutant. These findings have important implications and emphasize the need for early diagnosis of tuberculosis to decrease the chance of evolving highly fit drug-resistant strains.
The genomes of two Sulfolobus islandicus strains obtained from Icelandic solfataras were sequenced and analyzed. Strain REY15A is a host for a versatile genetic toolbox. It exhibits a genome of minimal size, is stable genetically, and is easy to grow and manipulate. Strain HVE10/4 shows a broad host range for exceptional crenarchaeal viruses and conjugative plasmids and was selected for studying their life cycles and host interactions. The genomes of strains REY15A and HVE10/4 are 2.5 and 2.7 Mb, respectively, and each genome carries a variable region of 0.5 to 0.7 Mb where major differences in gene content and gene order occur. These include gene clusters involved in specific metabolic pathways, multiple copies of VapBC antitoxin-toxin gene pairs, and in strain HVE10/4, a 50-kb region rich in glycosyl transferase genes. The variable region also contains most of the insertion sequence (IS) elements and high proportions of the orphan orfB elements and SMN1 miniature inverted-repeat transposable elements (MITEs), as well as the clustered regular interspaced short palindromic repeat (CRISPR)-based immune systems, which are complex and diverse in both strains, consistent with them having been mobilized both intra-and intercellularly. In contrast, the remainder of the genomes are highly conserved in their protein and RNA gene syntenies, closely resembling those of other S. islandicus and Sulfolobus solfataricus strains, and they exhibit only minor remnants of a few genetic elements, mainly conjugative plasmids, which have integrated at a few tRNA genes lacking introns. This provides a possible rationale for the presence of the introns.Iceland has been a rich source of hyperthermophilic crenarchaea over the past 3 decades and especially of acidothermophilic members of the order Sulfolobales. Many Sulfolobus islandicus strains ("Island" is German for "Iceland") have also yielded many novel viruses showing varied and sometimes unique morphologies and exceptional genome contents. These properties are consistent with these viruses constituting an archaeal lineage distinct from those of bacteria and eukarya, and they have now been classified into several new viral families (38, 63). In addition, a family of conjugative plasmids has been characterized, with most members deriving from Iceland, which appear to conjugate by a mechanism unique to the archaeal domain (18,37).Although the availability of genome sequences of Sulfolobus strains and their genetic elements has yielded important insights into the biology of these model crenarchaea, a major impediment to more detailed insights has been the paucity of robust and versatile vector-host systems for genetic studies. A few Sulfolobus species have been successfully employed as hosts for such systems, including Sulfolobus solfataricus strains P1 and 98/2 (22, 58), Sulfolobus acidocaldarius (57), and S. islandicus strain REY15A (54). To date, the genetic tools developed for the latter host are the most versatile and include the following: (i) Sulfolobus-Escherichia coli shuttle...
Volvariella volvacea, the edible straw mushroom, is a highly nutritious food source that is widely cultivated on a commercial scale in many parts of Asia using agricultural wastes (rice straw, cotton wastes) as growth substrates. However, developments in V. volvacea cultivation have been limited due to a low biological efficiency (i.e. conversion of growth substrate to mushroom fruit bodies), sensitivity to low temperatures, and an unclear sexuality pattern that has restricted the breeding of improved strains. We have now sequenced the genome of V. volvacea and assembled it into 62 scaffolds with a total genome size of 35.7 megabases (Mb), containing 11,084 predicted gene models. Comparative analyses were performed with the model species in basidiomycete on mating type system, carbohydrate active enzymes, and fungal oxidative lignin enzymes. We also studied transcriptional regulation of the response to low temperature (4°C). We found that the genome of V. volvacea has many genes that code for enzymes, which are involved in the degradation of cellulose, hemicellulose, and pectin. The molecular genetics of the mating type system in V. volvacea was also found to be similar to the bipolar system in basidiomycetes, suggesting that it is secondary homothallism. Sensitivity to low temperatures could be due to the lack of the initiation of the biosynthesis of unsaturated fatty acids, trehalose and glycogen biosyntheses in this mushroom. Genome sequencing of V. volvacea has improved our understanding of the biological characteristics related to the degradation of the cultivating compost consisting of agricultural waste, the sexual reproduction mechanism, and the sensitivity to low temperatures at the molecular level which in turn will enable us to increase the industrial production of this mushroom.
Leptospirosis, caused by pathogenic Leptospira spp., has recently been recognized as an emerging infectious disease worldwide. Despite its severity and global importance, knowledge about the molecular pathogenesis and virulence evolution of Leptospira spp. remains limited. Here we sequenced and analyzed 102 isolates representing global sources. A high genomic variability were observed among different Leptospira species, which was attributed to massive gene gain and loss events allowing for adaptation to specific niche conditions and changing host environments. Horizontal gene transfer and gene duplication allowed the stepwise acquisition of virulence factors in pathogenic Leptospira evolved from a recent common ancestor. More importantly, the abundant expansion of specific virulence-related protein families, such as metalloproteases-associated paralogs, were exclusively identified in pathogenic species, reflecting the importance of these protein families in the pathogenesis of leptospirosis. Our observations also indicated that positive selection played a crucial role on this bacteria adaptation to hosts. These novel findings may lead to greater understanding of the global diversity and virulence evolution of Leptospira spp.
scite is a Brooklyn-based startup that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
334 Leonard St
Brooklyn, NY 11211
Copyright © 2023 scite Inc. All rights reserved.
Made with 💙 for researchers