The genome of the protist parasite Entamoeba histolytica

Entamoeba histolytica is an intestinal parasite and the causative agent of amoebiasis, which is a significant source of morbidity and mortality in developing countries. Here we present the genome of E. histolytica, which reveals a variety of metabolic adaptations shared with two other amitochondrial protist pathogens: Giardia lamblia and Trichomonas vaginalis. These adaptations include reduction or elimination of most mitochondrial metabolic pathways and the use of oxidative stress enzymes generally associated with anaerobic prokaryotes. Phylogenomic analysis identifies evidence for lateral gene transfer of bacterial genes into the E. histolytica genome, the effects of which centre on expanding aspects of E. histolytica's metabolic repertoire. The presence of these genes and the potential for novel metabolic pathways in E. histolytica may allow for the development of new chemotherapeutic agents. The genome encodes a large number of novel receptor kinases and contains expansions of a variety of gene families, including those associated with virulence. Additional genome features include an abundance of tandemly repeated transfer-RNA-containing arrays, which may have a structural function in the genome. Analysis of the genome provides new insights into the workings and genome evolution of a major human pathogen.     

Mast cell stabilizing compound FPL 55618 reduces right ventricular hypertrophy and lung mast cell hyperplasia in chronically hypoxic rats

Summary Rats treated with chronic hypobaric hypoxia (21 days, 380 Torr) and mast cell stabilizing compund FPL 55618 had significantly less right ventricular hypertrophy and lung mast cell hyperplasia than rats subjected to chronic hypoxia alone. Right ventricular blood pressure was not reduced.Compound FPL 55618 was kindly donated by Mr P. Sheard of Fisons Ltd Pharmaceutical Division, Loughborough, Leicestershire, LE11 OQY England.This study was supported by grants from the Medical Research Council of Canada and St. Joseph's Hospital Foundation.     

The first vertebrate fossil from Socotra Island (Yemen) is an early Holocene Egyptian fruit bat

Data on the prehistoric biota of the Socotra Archipelago (Yemen) are scarce. We report on the first extinct vertebrate ever recorded from this western Indian Ocean island group. An exceptionally preserved adult specimen of Egyptian fruit bat Rousettus aegyptiacus was found in a calcite flowstone in Hoq Cave on the NE coast of Socotra Island. Accelerator mass spectrometry (AMS) radiocarbon dating on bone fragments estimates the fossil at ca. 7600–7400 cal a BP (radiocarbon age 6669 ± 70 ¹⁴C a BP) corresponding to an early Holocene wet period in southern Arabia and the Horn of Africa. Morphometric analysis of the skull compared to Recent specimens from the neighbouring mainlands finds the fossil morphologically most similar to Egyptian (Nile Valley and Libyan Desert), not to East African or Middle Eastern populations. The species is currently absent from the Horn of Africa (Somalia and Eastern Ethiopia). Although potentially a stray individual, we also discuss the palaeoenvironmental implications under the hypothetical scenario that the fruit bat is a remnant of an extinct resident population. If so, the extinction of an important pollinator and seed disperser may have impacted the Socotran terrestrial ecosystems.     

l-Isoleucine: An inducer of the feeding response in decapod crustaceans

Zusammenfassung Es wird gezeigt, dassl-Isoleucin eine starke Fressreaktion bei 6 Arten dekapoder Krebse hervorruft. Die wirksame Konzentration dieser Substanz war unter 2,3×10^–6 M/l.     

Fermentative digestion of food in the colobus monkey,Colobus polykomos

Summary Fermentation of leafy food occurs in the enlarged saccus gastricus of the colobus monkey with the formation of volatile fatty acid, as in the rumen of ruminant animals. About half of the digestible organic matter and cellulose of the diet is digested in this way.We wish to thank the Inter-University Council, the Nuffield Foundation and the Wellcome Trust for financial support. MrP. J. S. Dewey kindly made the determinations of cellulose and lignin.