Biomaterial Database

Structure and early embryonic expression of the zebrafish engrailed-2 gene. 1992

A Fjose, and P R Njølstad, and S Nornes, and A Molven, and S Krauss

Department of Molecular Genetics, Institute of Medical Biology, University of Tromsø, Norway.

The Drosophila homeobox gene engrailed (en) is needed for correct embryonic development, and related sequences are active during vertebrate embryogenesis. Here we report the protein coding sequence and embryonic expression pattern of the zebrafish engrailed-2 gene (eng-2) which is directly homologous to En-2 in mice and Xenopus. The predicted zebrafish Eng-2 protein shares 65% overall identity to its Xenopus counterpart. In addition to the highly conserved homeodomain region, sequence conservation is present within three short stretches in the N-terminal region. The embryonic expression of the eng-2 gene was analysed by in situ hybridization to whole-mount embryos and tissue sections. Transcripts are first detected in two lateral bands at the 10-h stage, when epiboly is completed. Within the next 2 h of development, these two bands migrate and fuse at the midline. By the time the neural keel becomes visible (11-12 h), a transverse stripe of eng-2 expressing cells is seen at the presumptive midbrain-hindbrain boundary. Later this stripe becomes significantly compressed along the AP axis, and in 24-h embryos eng-2 transcripts are detected mainly in the posterior midbrain. In the hindbrain, eng-2 expression seems restricted to the primordium of the cerebellum. A second site of activity was observed in each somite where specific myotomal cells, the muscle pioneers, express eng-2. Our observations are discussed in relation to early regionalization of the central nervous system (CNS) and the generation of morphological borders.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009419	Nerve Tissue Proteins		Proteins, Nerve Tissue,Tissue Proteins, Nerve
D009420	Nervous System	The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)	Nervous Systems,System, Nervous,Systems, Nervous
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D005314	Embryonic and Fetal Development	Morphological and physiological development of EMBRYOS or FETUSES.	Embryo and Fetal Development,Prenatal Programming,Programming, Prenatal
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
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
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