Molecular markers of differentiation in Caenorhabditis elegans obtained by promoter trapping

Abstract

Differentiation of specific cell types during animal development can be detected by monitoring expression of appropriate genes. For this study, six different P-galactosidase expression patterns which can be used as differentiation markers in the nematode Caenorhabditis elegans are described. An earlier promoter trap screen identified pools of recombinant plasmids which gave patterns of P-galactosidase expression when used to transform C. elegans. Each recombinant plasmid contained a random fragment of C. elegans genomic DNA fused upstream of a promoterless lac2 gene. Six of these pools were chosen, and individual pattern-producing plasmids within these pools were identified. The expression patterns have been characterized more thoroughly than in the original screen, thereby providing molecular markers for differentiation of several cell types. Many of the expression patterns involve more than one cell type. The genomic origin of the inserts of active plasmids were determined through localization on the physical genome map. 0 1993 Wiley-Liss, Inc.

A Family of at Least Seven β-Galactosidase Genes Is Expressed during Tomato Fruit Development

“…␤-Galactosidases are commonly associated with the hydrolysis of the milk sugar lactose into Gal and Glc by mammals and Escherichia coli. Due to the hardy and easily assayed nature of some ␤-galactosidases, E. coli LacZ has become one of the most conspicuous reporter gene systems in use today (Bayer and CamposOrtega, 1992;Young and Hope, 1993;Cui et al, 1994;Timmons et al, 1997;Lewis et al, 1998). However, LacZ has not been used for plant-based reporter gene systems due to high endogenous ␤-galactosidase activity in most plant tissues at neutral pH (Jefferson et al, 1987).…”

Purification and Characterization of Extracellular β-Galactosidase Secreted by Supension Cultured Rice (Oryza sativaL.) Cells

“…1,2) b-Gal is considered as one of the most important glycoside hydrolases due to its various applications in dairy and food industries, and in genetic engineering. [3][4][5][6][7][8][9] In plants, numerous studies of b-Gal have been done mainly related to fruit ripening, [10][11][12][13][14][15] and plant growth and development. [16][17][18][19][20][21][22][23][24] Most of the research on b-Gal in plants has been done on dicotyledons due to the larger amount of pectic polysaccharide than in monocotyledons, so that research of b-Gal from monocotyledons is very small.…”

Evidence Suggesting That a Fifth of Annotated Caenorhabditis elegans Genes May Be Pseudogenes

“…This laboratory has been determining gene expression patterns for the annotated C. elegans genes using reporter gene fusion technology as one approach through which to explore genome function (Hope 1991;Young and Hope 1993;Lynch et al 1995;Hope et al 1998). Although there are caveats in using this technology (e.g., the need for caution in assuming that an expression pattern observed is an accurate reflection of the expression of the endogenous gene), this approach has the advantage that an expression pattern is linked absolutely to an annotated gene in the genome.…”