实验仪器使用技术

Each chapter in this volume describes in detail the application of one or a group of photosensitive molecules to biological research. In this chapter, we take up general prefatory questions: how to determine which molecules are appropriate to use, and what type of compound delivery and light-t ...

The field of organic chemistry has provided neurobiologists with the ability to release biologically active neurotransmitters at precise locations and times of their choosing. These molecules are silent before the active molecule is released by photolysis, thus allowing for very a ...

Since much of the life of cells is controlled by their chemistry, caged compounds can be used to intervene in this life in a myriad of specific ways. Organic chemists have synthesized the widest possible array of caged compounds for use by biologists. The smallest possible chemical unit (protons) to t ...

The localized release of bioactive molecules from “caged compounds” through two-photon excitation (2PE) is an emerging technology for the study of biological processes in cell and tissue culture and whole animals. Several advantages are realized when 2PE drives the activation of the bi ...

Light sensing in nature has had the benefit of evolutionary time to optimize light-sensing and �photoresponsive molecular systems. Molecular biologists and neurobiologists have recently discovered that these optimized systems can be adapted for very specific purposes and to fi ...

Vertebrate and invertebrate rhodopsins are G-protein-coupled receptors that are involved in sensing light. Light activation of these receptors leads to intracellular responses via activation of G-proteins. Both receptor types belong to the Class A (rhodopsin-like) family of se ...

A leading cause of blindness worldwide is degeneration of the retinal photoreceptor cells. The two large classes of such disorders are retinitis pigmentosa, which affects ∼100,000 individuals in the USA, and macular degeneration, which affects ∼3,000,000. The causes of both disorders a ...

Photocontrol of protein function with azobenzene-based photoswitches promises to be a powerful tool for probing roles of proteins in vivo. In designing azobenzene-based switches for in vivo use, a number of challenges must be met. In this short review, we highlight progress in meeting some of t ...

Multiple strategies enabling the control of cellular function with light have been developed. These strategies include the expression of intrinsically photosensitive proteins and the use of photosensitive molecules that target native or exogenously expressed proteins. In p ...

Human genetic disease linked to mitochondrial DNA (mtDNA), the other genome in our cells, was first recognized in 1988 (1,2). Mitochondrial genetics has certain unique features (reviewed in ref. 3): 1) Maternal inheritance: Mitochondria are maternally inherited and therefore mtDNA mut ...

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant myopathy with a frequency of 1 in 20,000 and a penetrance of 95 % by the age of 20. affects specific muscle groups (facial, upper girdle, upper arm, pelvic girdle, and foot extensor) and displays a variety of phenotypic express ...

Single-strand conformational polymorphism (SSCP) analysis is a technique used to screen for the presence of sequence variations in short DNA fragments. This technique relies on the ability of single-stranded DNA molecules to fold into unique secondary structures, the conformati ...

Tay-Sachs disease is a severe, neurodegenerative disease fatal in childhood that is caused by deficiency of the enzyme β-hexosaminidase A (Hex A) (1). Tay-Sachs is most common in the Ashkenazi Jewish population, with an incidence of 1/3600 affected individuals and a carrier rate of approx 1 in 30 (1). ...

The detection of abnormal variations in a DNA sequence is a challenge for genetic research and clinical diagnostic applications. Among the different mutation detection methods currently available, DNA sequence analysis is largely considered the gold standard because it provides ...

Classic galactosemia is an autosomal recessive disorder caused by the deficiency of galactose 1-phosphate uridyltransferase, GALT (EC 2.7.7.12) (1). It presents with vomiting and diarrhea in neonates within a few days of milk intake. Most patients develop jaundice and hepatic failure. If ...

A conventional method used for DNA size measurement is gel electrophoresis. In this process, an electric field is applied to a gel medium and DNA molecules are separated by size. However, this process is slow and takes hours to separate different sizes of DNA fragments. Other physical and chemical p ...

Polyglutamine (polygln) expansion in specific proteins is one of the most intriguing pathogenic mechanisms causing adult-onset neurodegenerative disorders. In all the cases studied so far, the normal gene products tolerate a rather wide variation in size of a polygln tract (ranging t ...

Expansions of unstable CAG/CTG trinucleotide repeats have been identified as a common pathogenic mechanism in a growing number of hereditary neurodegenerative diseases, including myotonic dystrophy, spinal and bulbar muscular atrophy, Huntington’s disease (HD), spinoce ...

Microsatellite repeat expansions have been shown to cause a number of neurodegenerative diseases (1). Most of the disease genes identified to date involve the expansion of a trinucleotide repeat motif, but recently tetra- and pentanucleotide repeat expansions have been shown to cause m ...

Trinucleotide repeat sequences are present at approx 30,000-40,000 loci in the human genome (1). The majority of these repeats are below 35 copies and are stably transmitted. However, unstable trinucleotide repeat expansions at some loci have been found to be the causal mutation for nearly 20 g ...