@article{e63aa4aa9c444016a6353cf4ea9bc236,
title = "Developmental expression of the Xenopus Iroquois-family homeobox genes, Irx4 and Irx5",
abstract = "We have isolated and characterized the developmental expression of the Xenopus Iroquois 4 (Irx4) and Iroquois 5 (Irx5) homeodomain transcription factors. Irx4 is expressed in a subset of cells in the neural retina and the developing hindbrain and also, specifically, in the ventricle of the heart. Xenopus Irx5 is expressed in the developing midbrain, hindbrain, neural tube, and also in the retina.",
keywords = "Heart, Hindbrain, Midbrain, Retina, Ventricle",
author = "Garriock, {R. J.} and Vokes, {S. A.} and Small, {E. M.} and R. Larson and Krieg, {P. A.}",
note = "Funding Information: embryo. All embryos were assayed by whole-mount in situ hybridization as described by Gerber et al. (1999). A Dorsal view of stage 21 embryo showing Irx4 expression in discrete cells of the hindbrain. B, C Lateral views of Irx4 stained embryos at stages 26 and 32, respectively. Arrow in C indicates an intense region of expression in the hindbrain dorsal to the otic vesicle. D Dorsal view of embryo shown in C. Arrow indicates intense region of expression in the hindbrain. E Lateral view of Irx4 expression at stage 41, showing transcripts in the developing heart. F Transverse section through the heart of stage 41 embryo, showing Irx4 expression restricted to a subdomain in the ventricular myocardium. The ventricular and atrial myocardia are outlined in red and blue respectively. G Irx4 staining of an isolated stage 50 heart showing expression throughout the ventricle. H Lateral view of a stage 21 embryo showing Irx5 expression in eye, midbrain, hindbrain and neural tube. I Dorsal view of same embryo shown in H. J Irx5 expression in a stage 26, and K a stage 32 embryo, lateral views. L Diagram of a stage 34 embryo (lateral view) showing position of transverse sections (M–R). M–O Transverse sections through an Irx4-stained stage 34 embryo showing expression in a subset of the neural retina and in the anterior and posterior hindbrain. Open arrowhead in O indicates expression in isolated cells of hindbrain. P, Q Transverse sections through an Irx5-stained stage 34 embryo showing expression throughout the neural retina and in the midbrain. R Irx5 expression at stage 34, showing hindbrain expression immediately dorsal to otic vesicle. a Heart atria, cg cement gland, e optic vesicle or eye, en endocardium, fg foregut, h heart, hb hindbrain, l lens, lvr liver, mb midbrain, myo myocardium, n notochord, nt neural tube, ot heart outflow tract, ov otic vesicle, r retina, v heart ventricle Acknowledgements We thank Mike King for the Xenopus stage 42 tadpole library. This work was supported by the NHLBI, NIH grant HL63926 to P.A.K.. P.A.K. is the Allan C. Hudson and Helen Lovaas Endowed Professor of the Sarver Heart Center.",
year = "2001",
doi = "10.1007/s004270100147",
language = "English (US)",
volume = "211",
pages = "257--260",
journal = "Development Genes and Evolution",
issn = "0949-944X",
publisher = "Springer Verlag",
number = "5",
}