Abstract: Cells express distinct sets of genes in a precise spatio-temporal manner during embryonic development. There is a wealth of information about embryonic development in C. elegans, but much less is known about embryonic development at the molecular level in nematodes from other taxa. We are interested in insect pathogenic nematodes from the genus Steinernema as models of parasitism and symbiosis as well as a satellite model for evolution in comparison to C. elegans. We sequenced the transcriptomes of single embryos of two Steinernema species and two Caenorhabditis species at eleven specific stages during embryonic development for comparative analysis. We found that zygotic transcription initiates at different developmental stages in each species, with the Steinernema species initiating transcription at earlier developmental stages than Caenorhabditis. We found that ortholog expression conservation during development is highest at the later embryonic stages than at the earlier ones. Moreover, we found that the components of the neddylation pathway are highly upregulated during Steinernema early embryonic development contributing further to these early differences seen between the genera at the post-translational level. The surprisingly higher conservation of orthologous gene expression in later embryonic stages strongly suggests a funnel-shaped model of developmental gene expression divergence in nematodes. This work provides novel insight into embryonic development across distantly related nematode species and demonstrates that the mechanisms controlling early development are more diverse than previously thought at both the transcriptional and post-translational level. Overall design: We sequenced the transcriptomes of single embryos of two Steinernema species and two Caenorhabditis species during embryonic development at eleven specific stages (zygote, 2-cell, 4-cell, 8-cell, 24-44-cell, 64-78-cell, comma, 1.5-fold, 2-fold, moving, and L1) for comparative analysis.