Biomaterial Database

Expression pattern of homeobox-containing genes during chick embryogenesis. 1989

S E Wedden, and K Pang, and G Eichele

Harvard Medical School, Department of Cellular and Molecular Physiology, Boston, MA 02115.

We have isolated, sequenced and examined the expression pattern of two tandemly arranged homeobox-containing genes from the chicken. The predicted amino acid sequences of the homeodomain and the adjacent carboxyterminal portion of the protein of the first gene is virtually identical (99%) to that of murine homeobox 2.1 and hence we refer to it as Ghox 2.1 (Gallus homeobox). The closest mouse homologue of the second homeodomain is Hox 2.2 (95% identical within the homeobox), and hence referred to as Ghox 2.2. Northern analysis of embryonic RNA reveals major transcripts of 2 kb for Ghox 2.1 and 1.7 kb for Ghox 2.2. To investigate the transcript pattern, embryos of various stages were dissected into heads, trunks and limb buds and the RNA was analysed by Northern blotting and RNase protection assays. Ghox 2.1 transcripts are present in all three regions. Ghox 2.2 RNA is found in trunks and limb buds, but it is strikingly absent from the developing head. In situ hybridization with 35S-labelled antisense riboprobes derived from Ghox 2.1 demonstrates that this gene is expressed at high levels in spinal chord, myelencephalon and mesonephros. Dorsal root ganglia and the lung rudiment also contain Ghox 2.1 message, but in somewhat lower amounts. Mid- and forebrain, the heart, presomitic mesenchyme and notochord do not contain detectable levels of Ghox 2.1 mRNA. Of particular interest is the expression of Ghox 2.1 in a well-defined patch of mesenchymal tissue situated in an anterioproximal region of the limb bud.

UI	MeSH Term	Description	Entries
D008650	Mesonephros	One of a pair of excretory organs (mesonephroi) which grows caudally to the first pair (PRONEPHROI) during development. Mesonephroi are the permanent kidneys in adult amphibians and fish. In higher vertebrates, proneprhoi and most of mesonephroi degenerate with the appearance of metanephroi. The remaining ducts become WOLFFIAN DUCTS.	Wolffian Body,Mesonephroi,Body, Wolffian
D002490	Central Nervous System	The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.	Cerebrospinal Axis,Axi, Cerebrospinal,Axis, Cerebrospinal,Central Nervous Systems,Cerebrospinal Axi,Nervous System, Central,Nervous Systems, Central,Systems, Central Nervous
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D005121	Extremities	The farthest or outermost projections of the body, such as the HAND and FOOT.	Limbs,Extremity,Limb
D005801	Genes, Homeobox	Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.	Genes, Homeotic,Homeobox Sequence,Homeotic Genes,Genes, Homeo Box,Homeo Box,Homeo Box Sequence,Homeo Boxes,Homeobox,Homeoboxes,Hox Genes,Sequence, Homeo Box,Gene, Homeo Box,Gene, Homeobox,Gene, Homeotic,Gene, Hox,Genes, Hox,Homeo Box Gene,Homeo Box Genes,Homeo Box Sequences,Homeobox Gene,Homeobox Genes,Homeobox Sequences,Homeotic Gene,Hox Gene,Sequence, Homeobox,Sequences, Homeo Box,Sequences, Homeobox
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D015152	Blotting, Northern	Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.	Northern Blotting,Blot, Northern,Northern Blot,Blots, Northern,Blottings, Northern,Northern Blots,Northern Blottings
D015336	Molecular Probe Techniques	The use of devices which use detector molecules to detect, investigate, or analyze other molecules, macromolecules, molecular aggregates, or organisms.	Molecular Probe Technic,Molecular Probe Technics,Molecular Probe Technique,Technic, Molecular Probe,Technics, Molecular Probe,Technique, Molecular Probe,Techniques, Molecular Probe,Probe Technic, Molecular,Probe Technics, Molecular,Probe Technique, Molecular,Probe Techniques, Molecular