Search results for "Biomphalaria"

Recombinant functional multidomain hemoglobin from the gastropod Biomphalaria glabrata

2011

The extracellular hemoglobin multimer of the planorbid snail Biomphalaria glabrata, intermediate host of the human parasite Schistosoma mansoni, is presumed to be a 1.44 MDa complex of six 240 kDa polypeptide subunits, arranged as three disulfide-bridged dimers. The complete amino acid sequence of two subunit types (BgHb1 and BgHb2), and the partial sequence of a third type (BgHb3) are known. Each subunit encompasses 13 paralogus heme domains, and N-terminally a smaller plug domain responsible for subunit dimerization. We report here the recombinant expression of different functional fragments of BgHb2 in Escherichia coli, and of the complete functional subunits BgHb1 and BgHb2 in insect ce…

Red blood with blue-blood ancestry: Intriguing structure of a snail hemoglobin

2006

The phylogenetic enigma of snail hemoglobin, its isolated occurrence in a single gastropod family, the Planorbidae, and the lack of sequence data, stimulated the present study. We present here the complete cDNA and predicted amino acid sequence of two hemoglobin polypeptides from the planorbid Biomphalaria glabrata (intermediate host snail for the human parasite Schistosoma mansoni ). Both isoforms contain 13 different, cysteine-free globin domains, plus a small N-terminal nonglobin “plug” domain with three cysteines for subunit dimerization (total M r ≈ 238 kDa). We also identified the native hemoglobin molecule and present here a preliminary 3D reconstruction from electron microscopical …

The influence of adult worm age and definitive host on the transmission of Echinostoma caproni: egg hatchability and miracidial infectivity.

2012

AbstractWe analysed the influence of different ages of Echinostoma caproni adult worms reared in different definitive host-species on egg hatchability and miracidial infectivity. Eggs obtained from 2-, 4- and 6-week-old adult worms collected from rats, hamsters and mice, hatched miracidia that were used to infect laboratory-reared specimens of Biomphalaria glabrata. Highest egg hatchability was obtained with eggs derived from hamsters and mice. Egg hatchability did not seem to be affected by the age of E. caproni adult worms. Miracidial infectivity was not affected by the definitive host species. However, miracidial infectivity was affected by the age of adult worms when they developed in t…

8 Å cryo-EM structure of the giant hemoglobin from the planorbid snail Biomphalaria glabrata

2008

Until 2006, snail red hemoglobin remained a phylogenetic enigma because it occurs quite isolated in a single gastropod family, the Planorbidae, whereas all other gastropods use blue hemocyanin as a respiratory protein (for recent cryo-EM of hemocyanin, see [1,2]). Moreover, sequence data on this snail hemoglobin were completely lacking. In 2006, our group published the complete cDNA and predicted amino acid sequence of two Biomphalaria glabrata hemoglobin polypeptides, termed BgHb1 and BgHb2 [3]. (Biomphalaria is intermediate host of the human parasite Schistosoma mansoni that causes Bilharziosis.) Resembling pearl-chains, both polypeptide subunits encompass 13 different, cysteine-free glob…

Recombinant expression of gastropod (Biomphalaria glabrata) haemoglobin

2009

On the Ultrastructure and Function of Rhogocytes from the Pond Snail Lymnaea stagnalis

2015

Rhogocytes, also termed “pore cells”, occur as solitary or clustered cells in the connective tissue of gastropod molluscs. Rhogocytes possess an enveloping lamina of extracellular matrix and enigmatic extracellular lacunae bridged by cytoplasmic bars that form 20 nm diaphragmatic slits likely to act as a molecular sieve. Recent papers highlight the embryogenesis and ultrastructure of these cells, and their role in heavy metal detoxification. Rhogocytes are the site of hemocyanin or hemoglobin biosynthesis in gastropods. Based on electron microscopy, we recently proposed a possible pathway of hemoglobin exocytosis through the slit apparatus, and provided molecular evidence of a common phylog…