细胞技术

A genetic disease gene can be identified by three approaches: (1) Functional cloning in which a disease gene is identified based on biological background of a disease and the gene function without knowledge of chromosomal position of the gene, for example, identification of the globin gene mut ...

The identification of novel, developmentally regulated genes whose products play roles in the differentiation of specific vertebrate tissues and organs can be accomplished using a method called gene trapping (1-9). This technique involves inserting a marker gene, such as β-galacto ...

RNA localization is an important cellular mechanism for restricting the activities of regulatory proteins to cytoplasmic domains in oocytes and embryos (1). Cloning of these localized RNAs is obviously the first step in determining the functions of the encoded proteins. However, loca ...

Differential gene expression is an essential mechanism for the development of a single-celled zygote into a patterned multicellular organism with differentiated cell types and tissues. Therefore, the identification of differentially expressed genes provides an important ...

Preimplantation-stage mammalian embryos are very simple morphologically, being composed of mostly round cells that exhibit only a limited range of changes in cell shape, namely those associated with compaction and formation of the trophectoderm cell lineage. This morphological ...

Analysis of the genetic and molecular mechanisms of embryogenesis requires effective methods to find and isolate genes that are differentially expressed in normal and altered conditions. Comparative genomic screens can lead to the discovery of known or novel transcripts that chan ...

The generation of transgenic Drosophila has become a standard technique for the investigation of a wide variety of biological questions and phenomena. Virtually any cloned gene can be inserted into the genome using the P transposable element system. The gene of interest is first subcloned b ...

The cis-regulatory regions of developmentally active genes offer an accessible inroad from which to approach an understanding of the transcriptional networks that coordinate embryogenesis (1). In a developmental context, cis-regulatory regions control not only transcrip ...

The zebrafish has become a popular model system for genetic studies of vertebrate development. Zebrafish are amenable to such studies because the generation time of zebrafish is short, adults are small and easy to maintain, and females typically lay up to several hundred eggs per mating. Early d ...

The production and study of transgenic mice has proven invaluable in dissecting the complex genetic regulatory events that control mammalian development. Although the chick embryo is a classic model system in developmental biology, its scope is limited by the inability to routinely and ...

Fertilization in chickens occurs in the infundibulum of the reproductive tract within 15 min after ovulation of the yolk. The first cleavage division occurs 5 h later as the egg enters the shell gland. As the shell is calcified during the next 20-22 h, the embryo develops into a radially symmetric dome of c ...

Chicken blastodermal cell (CBC) culture is a useful tool for the production of germline and somatic chimeras. The long-term culture of CBCs may be used for studying the in vitro effects of various cytokines and growth factors at different stages of embryonic development (1). In addition, cell cul ...

Nuclear transplantation has been used for many years as an investigative tool with which to study the interactions between the nucleus and cytoplasm in early embryos and with which to characterize the developmental potency of embryonic and adult cell nuclei. As reviewed in a recent book on the s ...

The term “transgenic ” has been used since the beginning of the 1980s to define animals that had incorporated foreign DNA into their genome (1 ,2).Currently, transgenic animals include various species such as fish,poultry,rats,rabbits,pigs, sheep,goats,cattle,and mice (3 ,4).Mice r ...

The stable introduction of recombinant DNA into the germline of mammals is one of the major technological advances in biology and has greatly facilitated the study of gene function in development and disease,as well as the development of biotherapeutics. Landmark experiments conduct ...

Gene targeting in mouse embryonic stem (ES) cells has become a routine methodology to study gene function in vivo (1). Indeed, gene-targeting core facilities have been established at numerous institutions to facilitate the generation of targeted ES cell lines and the production of mouse ch ...

Gene targeting by homologous recombination in pleuripotent embryonic stem (ES) cells provides a powerful tool to introduce specific mutations in the genome of intact animal (1-5). It, therefore, allows to unravel the function of genes that control development and differentiation in the ...

The directed introduction of null mutations into defined genes has proven invaluable in elucidating gene function in a variety of experimental organisms. In the last decade or so this approach has been extended to mice (1) by the combined use of homologous recombination in murine embryonic st ...

Hematopoietic stem cells (HSC) play critical roles in maintaining blood cell production for the lifetime of the organism. Considerable progress has been made in their isolation from mouse bone marrow to high levels of purity based on a combination of cell-surface phenotype and functional ...

A major challenge facing investigators working in the field of hematopoietic stem cell (HSC) biology has been to develop a strategy to purify rare primitive HSCs from bone marrow. Several methods have been available including the commonly used technique of isolating HSCs based on a specific c ...