Engrailed Gene

Drosophila melanogaster

Background

Kim, C. (Artist). (2008). Transcription Factor. Duke University Howard Hughes Undergraduate Programs. Retrieved April 14, 2013, from http://howardhughes.trinity.duke.edu

Arthropod Embryological Development

• Engrailed acts as a segment-polarity gene in early embryological development of Drosophila

• It defines polarity along the anterior-posterior axis– Creates 14 parasegments

• Defines anterior-posterior boundary within each parasegment– Engrailed is found in the posterior region of each

parasegment• Has a role in brain development

– Defines mid-/hindbrain border– Guides neuronal axons

Segment Polarity Gene

• Engrailed gene is a segment polarity gene• Engrailed Protein

Schmidt, J. W. (Artist). (2004). Fig. 6 Pair rule. Wikimedia Commons. Retrieved April 14, 2013, from http://en.wikipedia.org/wiki/Drosophila_embryogenesis#Additional_segmentation_genes

Schmidt, J. W. (Artist). (2004). Figure 7. Reciprocal signaling between Wingless and Hedgehog producing cells. Wikimedia Commons. Retrieved April 14, 2013, from http://en.wikipedia.org/wiki/Drosophila_embryogenesis#Additional_segmentation_genes

Anterior-Posterior Axis Patterning in Drosophila

• One of the main types of genes involved is segmentation genes, including engrailed

• Embryological stripes are the result of 14 segments with engrailed expressed in the posterior region of each segment

Function

• Brain Development • Axon guidance

• First known for its role in arthropod embryological development

(2001-2002). MedEdCenter. Retrieved April 14, 2013, from http://www.edoctoronline.com

Nucleotide Sequence Analysis

Figure 1. Engrailed Gene DNA Sequence Analysis Comparison Among Fly, Norway Rat, Zebrafish, and Western Clawed Frog. Florence Corpet. (2013). MultiAlin result page. In MultiAlin. Retrieved April 9, 2013, from http://multalin.toulouse.inra.fr/multalin/cgi-bin/multalin.pl

DNA Phylogeny

Figure 2. Phylogenetic Tree of Engrailed Gene.(2013). Evry, France; Réseau National des. Génopoles. Retrieved April 9, 2013, from http://phylogeny.fr

Protein Sequence Analysis

Figure 3. Engrailed Gene’s Protein Sequence Analysis Comparison of Fly, House Mouse, Human, Norway Rat, Zebrafish, Western Clawed Frog, Purple Sea-Urchin, Nematode, and Domestic Chicken. Florence Corpet. (2013). MultiAlin result page. In MultiAlin. Retrieved April 9, 2013, from http://multalin.toulouse.inra.fr/multalin/cgi-bin/multalin.pl

Protein Sequence Phylogeny

Figure 4. Phylogenetic Tree of Engrailed Gene’s Protein.(2013). Evry, France; Réseau National des. Génopoles. Retrieved April 9, 2013, from http://phylogeny.fr

Research

• Kornberg et al. examined homozygous engrailed mutants and heterozygous (mosaic cell) mutants– Homozygous died with

fused, abnormal segments

– Mosaic cell suffer abnormalities in the posterior segments

• Hidalgo examined processes regulated by engrailed during morphogenesis of the fly wing– Found that engrailed has

more than just a patterning function

Bibliography• Brody, Thomas B. "Interactive Fly, Drosophila." Interactive Fly, Drosophila. Society for

Developmental Biology, 5 Dec. 1997. Web. 12 Apr. 2013.• Thomas Kornberg, Inga Sidén, Patrick O'Farrell, Michael Simon, The engrailed locus of

drosophila: In situ localization of transcripts reveals compartment-specific expression, Cell, Volume 40, Issue 1, January 1985, Pages 45-53, ISSN 0092-8674, 10.1016/0092-8674(85)90307-1. (http://www.sciencedirect.com/science/article/pii/0092867485903071)

• (2013). Evry, France; Réseau National des. Génopoles. Retrieved April 9, 2013, from http://phylogeny.fr

• Florence Corpet. (2013). MultiAlin result page. In MultiAlin. Retrieved April 9, 2013, from http://multalin.toulouse.inra.fr/multalin/cgi-bin/multalin.pl

• Kim, C. (Artist). (2008). Transcription Factor. Duke University Howard Hughes Undergraduate Programs. Retrieved April 14, 2013, from http://howardhughes.trinity.duke.edu

• Schmidt, J. W. (Artist). (2004). Fig. 6 Pair rule. Wikimedia Commons. Retrieved April 14, 2013, from

• Schmidt, J. W. (Artist). (2004). Figure 7. Reciprocal signaling between Wingless and Hedgehog producing cells. Wikimedia Commons. Retrieved April 14, 2013, from http://en.wikipedia.org/wiki/Drosophila_embryogenesis#Additional_segmentation_genes

• (2001-2002). MedEdCenter. Retrieved April 14, 2013, from http://www.edoctoronline.com