In situ hybridization was first described in the late 1960s by Pardue and Gall (1), who hybridized mouse ribosomal DNA sequences to a mouse chromosome spread. The technique came into broader use with the description of DNA probes for various viral sequences, and in the late 1980s with the publicatio ...

Neurodegenerative conditions are increasing in prevalence as the average human life expectancy rises. Alzheimer’s disease (AD) is the fourth commonest cause of death in the United States; the recent outbreak of new variant Creutzfeldt-Jakob disease (nvCJD) has raised the specter of a la ...

The infectious cause of the transmissible spongiform encephalopathies (TSEs), or prion diseases, is not yet clearly defined. Although minorities of researchers cling tenaciously to the virus hypothesis, the prion or protein-only hypothesis is now widely accepted by most scientis ...

It was believed that only proteins could carry out enzymatic reactions, and only nucleic acids could mediate inheritance. In recent years, the work of Cech and Altman and others has shown that nucleic acids can catalyze reactions. Now it has been shown that, in yeast, proteins can mediate inheritan ...

“Science is nothing but trained and organized common sense, differing from the latter only as a veteran may differ from a raw recruit.”a Prion disease is a disease of the second half of the twentieth century, but the scientific method that has elucidated this fascinating group of diseases is much olde ...

Various approaches have been taken to study the function of prion proteins. Biochemical methods were applied to search for a binding partner of PrPC which is attached to the cell surface by a glycosylphosphatidylinositol GPI anchor (1). The glial fibrillary acidic protein was one of the first p ...

Protein function is often observed directly following protein isolation, or is deduced by loss of function following gene knockout or by analogy with proteins of known function and similar amino acid sequence. None of these is true in the case of prion proteins because aside from the association ...

The fundamental problem in addressing prion diseases, or the transmissible spongiform encephalopathies, is finding an explanation for the massive neuronal death that occurs. Although some understanding of the mechanism by which neuronal death occurs comes from studies with scr ...

In the past two decades, thoroughly standardized mouse incubation time and brain lesion profile scoring assays have been developed to discriminate between prion strains. However, in these mouse infection experiments, large numbers of animals (about 20 mice/line) from three differe ...

A basic principle of microbiology that applies to all conventional infectious pathogens is that the disease phenotype is a function of both the infecting agent and the host’s response to it. All evidence indicates that this principle is also true for diseases acquired by infection with prions, ...

The prion hypothesis states that the partially protease-resistant and detergent-insoluble prion protein (PrPSc) is identical with the infectious agent, and lacks any detectable nucleic acids. Since the latter discovery, transgenic mice have contributed many important insig ...

This chapter reviews studies that involve the manipulation of prion protein (PrP) genes by transgenesis in mice. These consist of two approaches: PrP gene knockout and gene replacement using homologous recombination in embryonic stem cells; and microinjection of transgenes into fer ...

Prion diseases are fatal neurodegenerative disorders of humans and animals, which result from the conformational conversion of a normal, cell surface glycoprotein (PrPC) into a pathogenic isoform (PrPSc) that is the main component of infectious prions (1,2) . Familial prion diseases, ...

The preceding chapters have dealt with the detection of gene mutations and the following chapters deal with protein analysis. This chapter links the two by describing the effect that different types of mutations have on protein synthesis, and how this may be used in the investigation of muscular ...

Progressive muscle wasting, which leads to severe disability and early death, make Duchenne and Becker muscular dystrophies (DMD/BMD) highly distressing disorders to both patient and family. Diagnosis in pregnancy, therefore, is frequently considered by couples in which the woman ...

Immunohistochemistry/immunocytochemistry (ICC) and allied techniques are used to visualize and localize specific tissue components. The principle of ICC is the binding of an antibody (Ab) to a specific antigen. Allied techniques include the labeling of glycoproteins with lect ...

The gene involved in Duchenne and Becker muscular dystrophies (DMD/ BMD) was the first human gene to be successfully identified by the approach of reverse genetics, or positional cloning (1), leading to the recognition of this approach as a valid and useful way of identifying genes for which the bio ...

In the decade following the identification of mutations in the dystrophin genein Duchenne (1) and Becker (2) muscular dystrophies (DMD/BMD), defects in components of the dystrophin-glycoprotein complex (DGC), which links F-actin in the cytoskeleton with laminin in the extra cellular ...

The large majority of situations in which prenatal diagnosis is applied in the muscular dystrophies (MDs) is for Duchenne muscular dystrophies (DMD). Hence, discussion of fetal muscle biopsy in this chapter is limited to DMD, although, in principle, it should be applicable to any other primary ...

Protein analysis usually requires the application of immunological techniques, and, in the preceding chapter, the use of antibodies (Abs) to label proteins in tissue sections has been described. Proteins in unfixed frozen sections are in near native form, and analysis of proteins in these c ...