遗传学实验技术

Meiosis is one of the key stages of spermatogenesis during which two rounds of chromosome segregation follow a single doubling of the DNA, thus reducing the chromosome number to produce haploid cells. Drosophila spermatocytes have been used extensively to study the basic mechanisms that g ...

In this chapter, I hope to convince the reader that Drosophila spermatogenesis is an ideal system for the cytogeneticist. Spermatogenesis is relatively simple, dispensable for adult viability, and amenable to genetic, cell biological, and biochemical approaches. The stages of sper ...

Recombinant baculovirus expression systems are among the most commonly used for expressing foreign genes in eukaryotic cells (1,2). This eukaryotic expression system became very popular for many reasons, including 1. potentially high-protein expression levels, 2. ease and speed of ...

Current polymerase chain reaction (PCR) innovations provide powerful tools for the cloning of previously unknown genes as well as characterization of their functions. Examples of the latter used include PCR-mediated in vitro mutagenesis and recombination of the cloned genes. PCR ap ...

Because many genes of biological interest are larger than the maximum size that current synthetic oligonucleotide synthesizers can produce (approx 110 bases), there is a need for methods that allow rapid production and expression of genes constructed from multiple synthetic DNA frag ...

A large variety of procedures of site-directed mutagenesis based on polymerase chain reaction (PCR) have been developed over the last decade. Among them, the “megaprimer” method, originally reported in 1990 (1), and its subsequent updates (8,10) still retain their popularity because they ...

Molecular cloning has proven to be a powerful tool in biology, and chimeric clones are useful in a variety of fields including microbial pathogenesis and the development of vaccines. Chimeras can be created from DNA by using conventional cloning techniques, specifically restriction cl ...

Since their first description in 1991 (1), CAG-disease causing genes are increasing in number. Up to date, there are at least nine genetic diseases caused by CAG expansions. The creation of transgene and knock-in mice with CAG expansions is an useful tool for understanding the pathological mech ...

Site-directed mutagenesis is a commonly used tool for identifying the role of specific amino acids in the structure and function of proteins. Various methods of in vitro mutagenesis have been described and are widely used for introducing modified coding sequences (1-7). In comparison, pol ...

Signature tagged-mutagenesis (STM) is a functional genomics technique that identifies microbial genes required for infection within an animal host, or within host cell (1,2). As first described by Hensel et al., 1995 (3), transposon mutants are generated and each one tagged with a unique DNA se ...

Mutagenesis is a popular tool used in the analysis of protein structure and function. Polymerase chain reaction (PCR)-based mutagenesis can be used to introduce mutations with the use of the appropriate primer. Although the majority of attention has been given to site-directed mutagene ...

In vitro polymerase chain reaction (PCR) -based recombination methods are used to shuffle segments from various homologous DNA sequences to produce highly mosaic chimeric sequences. Genetic variations created in the laboratory or existing in nature can be recombined to generate li ...

Many foreign DNAs, such as some virus DNAs and almost all transposable elements (transposons), are capable of integrating host genomes, and the effects of integration can be pleiotropic. To investigate the mechanism and biological effect of foreign DNA insertions, characterization of ...

Vectorette polymerase chain reaction (PCR) is a method designed to amplify DNA when the sequence of one end of the target DNA is unknown (1,2). This technique, therefore, gives a handle on unknown sequence, which flanks DNA that has already been characterized, or sequenced. The vectorette method w ...

The ability of the polymerase chain reaction (PCR) to amplify DNA depends upon the existence of defined primer binding sites. Thus, to amplify a region of flanking unknown DNA sequence, a defined primer binding site must be created. Numerous strategies have been found to do this, such as addition of nu ...

Cells undergoing apoptosis display a number of morphological changes, including chromatin condensation, cytoplasmic shrinkage, membrane blebbing, and the formation of apoptotic bodies (1). These morphological changes are accompanied by structural changes within the cel ...

The epidermal cells, a derivative of ectoderm during embryogenesis of insects, contribute to the distinct cuticular pattern and form of the different stages that appear during their ontogeny. The type of cuticular products is the result of gene expression of the individual epidermal cel ...

The Drosophila wing somatic mutation and recombination test (SMART; also known as the wing spot test) provides a rapid means to assess the potential of a chemical to induce loss of heterozygosity (LOH) resulting from gene mutation, chromosomal rearrangement, chromosome breakage, or chro ...

The imaginal discs of Drosophila melanogaster are saclike clusters of cells that generate the epidermal structures of the adult head, thorax, and external genitalia during metamorphosis. Imaginal disc precursor cells are segregated from larval cells during embryogenesis and fo ...

The central nervous system (CNS) of the third instar larva is a tissue of choice for studying conventional mitotic cycles in Drosophila. For example, squash preparations of the larval CNS are routinely used to investigate chromosome structural and numerical anomalies in late larval leth ...