A general field bioassay for detecting biologically active compounds in plants and insects has been developed and tested for efficacy and sensitivity. Methanolic extracts, in sucrose solution, of 20 plant and six caterpillar species were offered to the ponerine ant Paraponera clavata and the feeding preferences observed. The bioassay resulted in the detection of nine plant and three caterpillar...

The Lewis (LEW) and Fischer 344 (F344) inbred rat strains react differentially to acute morphine administration for a variety of behavioral and neurochemical measures. Investigations into effects of chronic morphine are less common, and investigations assessing dependence have been limited to those utilizing antagonist-precipitated withdrawal. The present experiment extended these assessments b...

The laboratory rat, Rattus norvegicus, was the first mammalian species domesticated for scientific research, which work dating back to before 1850. From this auspicious beginning, the rat has become the most widely studied experimental animal model for biomedical research (Jacob, 1999). Since the development of the first inbred rat strain by King 1909, over 500 inbred rat strains have been deve...

Cognitive ability and the properties of brain oscillation are highly heritable in humans. Genetic variation underlying oscillatory activity might give rise to differences in cognition and behavior. How genetic diversity translates into altered properties of oscillations and synchronization of neuronal activity is unknown. To address this issue, we investigated cellular and synaptic mechanisms o...

Hemochromatosis is caused by mutations in HFE, a protein that competes with transferrin (TF) for binding to transferrin receptor 1 (TFR1). We developed mutant mouse strains to gain insight into the role of the Hfe/Tfr1 complex in regulating iron homeostasis. We introduced mutations into a ubiquitously expressed Tfr1 transgene or the endogenous Tfr1 locus to promote or prevent the Hfe/Tfr1 inter...

For most imprinted genes, a difference in expression between the maternal and paternal alleles is associated with a corresponding difference in DNA methylation that is localized to a differentially methylated domain (DMD). Removal of a gene's DMD leads to a loss of imprinting. These observations suggest that DMDs have a determinative role in genomic imprinting. To examine this possibility, we i...

We examined the behavior of three inbred mouse strains (129/SvPasIco, C57BL/6J, and DBA/2J) exposed to an object soaked with the chemical component of the aversive scent (toluquinone odor) emitted by a myriapod species (Ommatoiulus sabulosus) in the presence of a predator. Subjects were exposed to the odor for three consecutive days. Behavioral responses to the toluquinone odor were characteriz...

Human mucopolysaccharidosis VII (MPS VII, Sly syndrome) results from a deficiency of beta-glucuronidase (GUS) and has been associated with a wide range in severity of clinical manifestations. To study missense mutant models of murine MPS VII with phenotypes of varying severity, we used targeted mutagenesis to produce E536A and E536Q, corresponding to active-site nucleophile replacements E540A a...

The adherence property of 70 verotoxigenicE. coli (VTEC) strains, not belonging to O157: H7 serotype (non-O157) was checked on HeLa cells adherence assay. These strains were isolated from patients with diarrhea and healthy individuals. The results obtained in this study revealed that localised adherence (LA) was manifested by 3 strains of which two belonged to serogroups O111, O127 and the thir...

To evaluate the effect of increased housing density in a hybrid mouse strain, we evaluated a panel of physiological and behavioral traits in animals that were housed in groups of 3, 5, 8, or 12, using cages that provide 78.1 in2 of floor space. Such groupings resulted in cage densities that ranged from half to almost twice the density recommended by the Guide for the Care and Use of Laboratory ...