My lab’s primary research focus is the genetic regulation of early neural development, primarily using the African clawed frog, Xenopus, as a model system. We are currently focusing on the mechanism by which members of the paired-type homeobox gene family regulate gene expression in the developing neural retina. In particular, we are investigating the Rx (retinal homeobox) and related genes. We will compare and contrast the proteins encoded by these genes to gain a better understanding of how they function to regulate gene expression in early development of the neural retina. Rx is expressed in the anterior neural plate and the progenitors of the eye fields, where it plays an essential role in eye development. In particular, we are interested in the involvement of Rx in retinal progenitor cells. We are interested in the Rx genetic pathway, including understanding how proper spatial and temporal Rx expression is regulated, leading to normal eye development. We will also try to identify and characterize genes that are regulated by Rx. These genes should also play important roles in eye development. We believe that a better understanding of the Rx genetic pathway will lead to a better understanding of the early genetic events of eye development. We are also investigating the involvement of Rx in retinal regeneration. The amphibian eye can regenerate after physical damage. This process involves the recruitment/generation of retinal stem and progenitor cells. Rx is expressed in these cells and is necessary for their recruitment at the regenerating wound. We are interested in investigating the role Rx plays in retinal progenitor cell development in the regenerating retina. We hope that a better understanding of the process of retinal stem/progenitor cell recruitment in amphibians will lead to insights into promoting retinal regeneration in humans.
Pan, Y., Martinez-de Luna, R.I., Lou, C.-H., Nekkalapudi, S., Kelly, L.E., Sater, A.K. and El-Hodiri, H.M. 2010. Regulation of photoreceptor gene expression by the retinal homeobox (Rx) gene product. Dev. Biol.. Vol. 339. : 494-506.
Wilson, J.M., Martinez-de Luna, R.I., El-Hodiri, H.M., Smith, R., King, M.W., Mescher, A.L., Neff, A.W., and Belecky-Adams, T.L. 2010. RNA helicase Ddx39 is expressed in the developing central nervous system, limb, otic vesicle, branchial arches and facial mesenchyme of Xenopus laevis. Gene Expression Patterns. Vol. 10. : 44-52.
Stanke, J., Moose, H.E., El-Hodiri, H.M., and Fischer, A.J. 2010. A comparative study of Pax2 expression in glial cells in the retina and optic nerve of birds and mammals. J. Comp. Neurol.. Vol. 518. : 2316-2333.
Martinez-De Luna, R.I., Moose, H.E., Kelly, L.E., Nekkalapudi, S., and El-Hodiri, H.M. 2010. Regulation of retinal homeobox gene transcription by cooperative activity among cis-elements. Gene. Vol. 467. : 13-24.
El-Hodiri, H.M., Pan, Y., Martinez-De Luna, R.I., Nekkalapudi, S., Kelly, L.E. 2009. The Retinal Homebox (Rx) Gene Product Is Necessary for Normal Expression of Photoreceptor-Specific Genes and Photoreceptor Function [Abstract]. Invest Ophthalmol Vis Sci. no. 50: ARVO E-Abstract 488 (Published)
Fullenkamp AN, El-Hodiri HM. 2008. The function of the Aristaless-related homeobox (Arx) gene product as a transcriptional repressor is diminished by mutations associated with X-linked mental retardation (XLMR). Biochem Biophys Res Commun. Vol. 377, no. 1. (December 5): 73-78. (IF: 2.749)
Ignatius MS, Moose HE, El-Hodiri HM, Henion PD. 2008. colgate/hdac1 Repression of foxd3 expression is required to permit mitfa-dependent melanogenesis. Dev Biol. Vol. 313, no. 2. (January 15): 568-583. (IF: 4.714)
El-Hodiri, H.M., Martinez-De Luna, R.I., Kelly, L.E., and Moose, H.E. 2008. Expression of the Retinal Homeobox (Rx) Gene in Xenopus Retinal Progenitor Cells Requires Cooperative Activity of Conserved Genomic Elements [Abstract]. Invest Ophthalmol Vis Sci. ARVO E-Abstract 5398, Vol. 49 (Published)
Rorick AM, Mei W, Liette NL, Phiel C, El-Hodiri HM, Yang J. 2007. PP2A:B56epsilon is required for eye induction and eye field separation. Developmental Biology. Vol. 302, no. 2: 477-493.
Kelly LE, Nekkalapudi S, El-Hodiri HM. 2007. Expression of the forkhead transcription factor FoxN4 in progenitor cells in the developing Xenopus laevis retina and brain. Gene Expression Patterns. Vol. 7, no. 3: 233-238.
Martinez-De Luna RI, El-Hodiri HM. 2007. The Xenopus ortholog of the nuclear hormone receptor Nr2e3 is primarily expressed in developing photoreceptors. International Journal of Developmental Biology. Vol. 51, no. 3: 235-240.
Sater, A.K. and El-Hodiri, H., Zhang, L., Shah, R., Mathers, P.H., and Jamrich, M. 2006. Analysis of MAP kinase pathways in vertebrate development. In Analysis of Growth Factor Signaling in Embryos. Edited by M. Whitman and A.K. Sater. Boca Raton, Fl, USA: CRC Press. 61-86.
El-Hodiri, H.M., and Kelly, L.E., Nekkalapudi, S., and Martinez-De Luna, R.I. 2006. Involvement of the Forkhead Transcription Factor FoxN4 in Xenopus Retinal Progenitor Cell Development [Abstract]. Invest. Ophthalmol. Vis. Sci.. no. 47: E-Abstract 5757 (Published)
Chow, S.J., Hermesz, E., Hatta, T., Feltner, D., El-Hodiri, H.M., Jamrich, M., A Mahon, K.A. 2006. Conserved regulatory elements established the dynamic expression of Rpx/HesxI in early vertebrate development. Dev. Bio.. Vol. 292: 533-545.
El-Hodiri, H.M., and Kelly, L.E. 2005. The aristaless-related homeobox (arx) gene product is essential for normal forebrain development [Abstract]. no. 283: 670 (Published)
El-Hodiri, H.M., Nekkalapudi, S., Kelly, L.E., and Bertuzzi, S. 2005. The retinal homeobox (Rx) gene product acts as a transcriptional activator in cooperation with other retinal transcription factors [Abstract]. Invest. Ophthalmol. Vis. Sci.. E-Abstract 3133, Vol. 46 (Published)
El-Hodiri, H.M., and Kelly, L.E. 2005. The aristaless-related homeobox (arx) gene product is essential for normal forebrain development [Abstract]. Society for Neuroscience. no. Program No, 597.5. Washington, DC, USA: Online (Published)
El-Hodiri, H.M., Seufert, D.W., and Prescott, N. 2004. Overexpression analysis of Arx in Xenopus forbrain development [Abstract]. Presented at the Pediatric Academic Society Annual Meeting. San Fransico, CA. (May) (Published)
Tseng, H.T., Brownwell, I., Hashimoto, R., El-Hodiri, H., Medina-Martinez, O., Shah, R., Zilinski, C., and Jamrich, M. 2004. Role of Fox genes during Xenopus embryogenesis. In The Vertebrate Organizer. Edited by H. Grunz. Columbus, OH: Springer Verlag. 41-54.
El-Hodiri, H.M., Seufert, D.W., Prescott, N.L. 2004. The Xenopus aristaless-related homeobox (sarx) gene product functions as both a transcriptional activator and repressor in forebrain development. Program No. 482.3 [Abstract]. Society for Neuroscience Online Abstract Viewer/Itinerary Planner. Washington, DC, USA (Published)
El-Hodiri, H.M. and Nekkalapudi, S. 2004. Isolation and preliminary characterization of the Xenopus laevis Rx2A [Abstract]. Invest. Ophthalmol. Vis. Sci.. ARVO E-Abstract, Vol. 45: 652 (Published)
Herman, G.E., and El-Hodiri, H.M. 2003. Review of Cytogenetic and Genome Research. no. 99: 229-235. (Published)
El-Hodiri, H.M. and Prescott, N.L. 2003. Identification and Characterization of a Xenopus Rx-like Gene [Abstract]. Invest. Ophthalmol. Vis. Sci.. ARVO E-Abstract, Vol. 44: 2263 (Published)
El-Hodiri, H.M., Zhang, L., Ma, H.-F., and Jamrich, M. 2001. Characterization of the Xenopus laevis Rx1A promoter in transgeneic frogs [Abstract]. Invest Ophthamol. Vis. Sci. Vol. 42, no. 4: S657 (Published)
El-Hodiri, H.M., Zhang, L., Ma, H.-F., and Jamrich, M. 2001. Characterization of the Xenopus laevis Rx1A promoter in transgenic frogs [Abstract]. no. 235: 280 (Published)
El-Hodiri, H.M., and Etkin, L.D. 1998. Xenopus nuclear factor 7 (XNF7) function is required for expression of specific genes in the mid-blastula embryo. [Abstract]. Dev. Biol.. Vol. 198: 87 (Published)
Uzgare, A., Uzman, A., El-Hodiri, H.M., and Sater, A.K. 1998. MAP kinase and neural specification. Pro. Natl. Acad. Sci.. Vol. 95: 14833-14838.
Etkin, L.D., El-Hodiri, H.M., Nakamura, H., Wu, C.-F., Shou, W., and Gong, S.-G. 1997. Review of Characterization of xnf7 function during early development in Xenopus. no. 173: 144-146. (Published)
El-Hodiri, H.M., Shou, W., and Etkin, L.D. 1997. Involvement of Xenopus nuclear factor 7 in dorsal/ventral patterning [Abstract]. Dev. Biol.. Vol. 186: 326 (Published)
El-Hodiri, H.M., Shou, W., Li, X., and Etkin, L.D. 1996. Involvement of Xenopus nuclear factor 7 in dorsal/ventral patterning [Abstract]. Dev. Biol.. Vol. 175: 390 (Published)
El-Hodiri, H.M., and Perry, M. 1993. Developmental regulation of Xenopus laevis histone H2A and H2B gene transcription [Abstract]. J. Cell. Biochem.. Vol. 17A: 193 (Published)