A bacterial artificial chromosome library for Biomphalaria glabrata, intermediate snail host of Schistosoma mansoni

Abstract

To provide a novel resource for analysis of the genome of Biomphalaria glabrata, members of the international Biomphalaria glabrata Genome Initiative (biology.unm.edu/biomphalaria-genome.html Key words: genomics -gene discovery -fingerprinting -schistosomiasis -medical malacologyThe application of molecular approaches continues to contribute novel insights into the biology, including genomics of molluscs . To date, several mitochondrial genomes of molluscs have been sequenced (DeJong et al. 2004, Mizi et al. 2005, but the nuclear genome of a representative of the Phylum Mollusca remains to be fully characterized. In fact, lophotrochozoan protostomes of which mollusca represent the largest group (Rouse 1999), are underrepresented among the animals from which the current assembly of fully sequenced genomes has been obtained. Thus, genomic data from a mollusc will help fill a gap in the information on the evolutionary history of animal life (Collins et al. 2003). Molluscs are a highly diverse group that includes some of the largest, longest living, and most intelligent invertebrates. Genome information will instruct on several remarkable properties of molluscs such as shell formation (biomineralization; Milet et al. 2004), the evolution of body asymmetry (Schilthuizen & Davison 2005), and hermaphrodism (Paraense & Corrêa 1988). Molluscs are also being used to study pharmo-toxicology (Terlau & Olivera 2004); neuroendocrinology (Altelaar et al. 2005); parthenogenesis (Jokela et al. 2003); and the molecular basis of behavior and learning (Williamson & Chrachri 2004, Zhurov et al. 2005. Molluscs serve as bioindicators for monitoring of the environment (Zhao et al. 2005), and (snails especially) are useful for understanding how natural selection operates (Vermeij 2002). Furthermore, molluscs are economically important as a major source of food, can destroy crops, colonize and impact new habitats as invasive species (Pointier et al. 2005), and transmit medically important pathogens.The latter applies to the freshwater gastropod Biomphalaria glabrata (Planorbidae, Basommatophora). This snail serves as one of the most important intermediate hosts for a widespread pathogen of humans, the digenetic trematode Schistosoma mansoni (Paraense & Corrêa 1963, Morgan et al. 2001). This parasite causes intestinal schistosomiasis, a debilitating disease that afflicts over 50 million humans (Chitsulo et al. 2004). To a large extent, the geographic distribution of B. glabrata defines the et al. 2004). B. glabrata also hosts a variety of other digenetic trematodes and has been adopted as the most commonly used model host to study the basic biology of digeneansnail interactions (Lie 1982, Adema & Loker 1997, Vergote et al. 2005. As one example, B. glabrata has been found to produce after exposure to digeneans a unique family of hemolymph molecules termed FREPs (fibrinogen-related proteins). FREPs consist of a juxtaposition of fibrinogen and immunoglobulin superfamily domains, and have proven to be remarkably diverse in their composition...

Comparative ORESTES-sampling of transcriptomes of immune-challenged Biomphalaria glabrata snails

“…The distribution of B. glabrata largely defines the areas that are endemic for schistosomiasis in South and Central America (Dejong et al, 2003), but only a low proportion of snails in the field is patently infected with schistosomes (de Souza et al, 1994) and some B. glabrata are naturally resistant (Paraense and Correa, 1963). Increasingly, experimental study of B. glabrata as intermediate host of schistosomes and related digenetic trematode parasites incorporates characterization of the genome (Adema et al, 2006;DeJong et al, 2004;Raghavan and Knight, 2006), the proteome (Bouchut et al, 2006b;Vergote et al, 2005) and especially the transcriptome (Bouchut et al, 2006a;Jung et al, 2005;Knight et al, 1999;Lockyer et al, 2007a;Lockyer et al, 2007b;Miller et al, 2001;Mitta et al, 2005;Nowak et al, 2004;Raghavan et al, 2003) …”

Identification and characterisation of functional expressed sequence tags-derived simple sequence repeat (eSSR) markers for genetic linkage mapping of Schistosoma mansoni juvenile resistance and susceptibility loci in Biomphalaria glabrata

“…Furthermore, because these markers were developed based on expressed sequences, we hope a novel gene silencing RNA interference (RNAi) soaking method that we have recently developed (Knight et al, 2011b) will help to reveal the function of these identified genes as linked to B. glabrata susceptibility and resistance to S. mansoni infection. In addition, using the cloned markers as probes, corresponding bacterial artificial chromosomes (BACs) have now been identified and are currently being utilised (Adema et al, 2006) for the physical mapping of ex vivo B. glabrata chromosomes (Odoemelam et al, 2009, 2010). …”

Comparative immunogenomics of molluscs

“…To better qualify for full genome sequencing, some research communities developed complementary genomic resources. Bacterial artificial chromosome (BAC) libraries were developed for several molluscs like B. glabrata (Gastropda) and the oysters Crassostrea virginica and C. gigas , to gain initial access to genomic information (Adema et al, 2006; Cunningham et al, 2006; Raghavan et al, 2007). BAC libraries consist of considerable numbers of clones that represent the full genome with large (>100kb) inserts of molluscan genomic DNA.…”