Send to

Choose Destination
Dev Biol. 2004 Dec 15;276(2):493-507.

Identification of lineage-specific zygotic transcripts in early Caenorhabditis elegans embryos.

Author information

Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.


During Caenorhabditis elegans embryogenesis, a maternally supplied transcription factor, SKN-1, is required for the specification of the mesendodermal precursor, EMS, in the 4-cell stage embryo. When EMS divides, it gives rise to a mesoderm-restricted precursor, MS, and an endoderm-restricted precursor, E. To systematically identify genes that function as key regulators of MS and/or E-derived tissues, we identified, by microarray analyses, genes that are newly transcribed within a short developmental window (approximately 30 min) encompassing the generation and fate specification of the MS and E blastomeres. By comparing total cDNAs generated from individual, carefully staged embryos, we identified 275 genes up-regulated in 12-cell embryos compared to 4-cell embryos. Fifty of these 275 genes are down-regulated in 12-cell skn-1 mutant embryos and are designated skn-1-dependent zygotic (sdz) genes. The spatial and temporal expression patterns in C. elegans embryos of 10 randomly selected sdz genes were analyzed by a nuclear GFP reporter driven by the endogenous 5' regulatory sequence of each gene. GFP expression, although absent at the 4-cell stage, was detected at the 12- to 16-cell stage for all 10 genes and was restricted to EMS-derived lineages for 7 of the 10. Among the seven lineage-specific genes, three genes are expressed equally in both MS and E lineages, two are expressed exclusively or predominantly in the MS lineage, and two are expressed exclusively in the E lineage. Depletion of skn-1 by RNAi abolishes the expression of all seven reporter transgenes in vivo, confirming that these genes are indeed skn-1 dependent. These results demonstrate the successful combination of single-staged embryo cDNAs, genetic mutants, and whole transcriptome microarray analysis to identify stage- and lineage-specific transcripts in early C. elegans embryos.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center