Biomphalaria glabrata (BglaB1)

Biomphalaria glabrata Assembly and Gene Annotation

The Biomphalaria glabrata data and its display on Ensembl Genomes are made possible through a joint effort by the Ensembl Genomes group and VectorBase, a component of VEuPathDB.

About Biomphalaria glabrata

Freshwater snails of the genus Biomphalaria are intermediate hosts for flatworm parasites of the genus Schistosoma, causative pathogens of human schistosomiasis, in South America, the Greater and Lesser Antilles, Africa, Madagascar and the Arabian peninsula. Biomphalaria glabrata, a neotropical snail, is the major intermediate host of Schistosoma mansoni.

Patently infected B. glabrata snails shed and seed their aquatic environment with numerous free-swimming cercariae, the stage of S. mansoni that is infective for humans. Water contact leads to infection because cercariae can actively penetrate human skin. Inside the human host, schistosome parasites mature and reproduce sexually. Parasite eggs are released in the feces and/or urine of infected humans. Parasite larvae called miracidia hatch from the eggs and swim to locate and infect B. glabrata for completion of the S. mansoni life cycle.

BB02 strain

Biomphalaria glabrata snails were collected by Omar dos Santos Carvalho (CPRR/Fiocruz) in the south east of Brazil (19o59' S 44o02' W), Belo Horizonte, district of Barreiro. Morphology-based species identification was confirmed by PCR_RFLP; 16S rDNA, NADH dehydrogenase 1 sequences (AY737280, AY737281). Lab-reared offspring of the wild caught snails proved susceptible to multiple strains of Schistosoma mansoni. BB02 snails are maintained as inbred lines at several research groups. A BAC library is available for this strain from the Arizona Genomics Institute (Tucson AZ, USA).

Genomic DNA was extracted from whole body soft tissues minus the reproductive organs of adult BB02 snails (Coen Adema, UNM) and applied for genome sequencing at The Genomics Institute (TGI), Washington University, St Louis MO.

Source: VectorBase

BglaB1 assembly

Assembled and submitted by Washington University (WashU).

BglaB1.7 gene set

Community annotation patch build for July 2019.


  1. Whole genome analysis of a schistosomiasis-transmitting freshwater snail.
    Adema CM et al.. 2017. Nat Commun.. 8

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AssemblyBglaB1, INSDC Assembly GCA_000457365.1,
Database version104.1
Golden Path Length916,391,120
Genebuild byVEuPathDB
Genebuild methodMaker genebuild
Data sourceVectorBase

Gene counts

Coding genes25,561
Non coding genes6,250
Small non coding genes6,248
Long non coding genes2
Gene transcripts44,299


Short Variants10,031,395

About this species