Biomaterial Database

Jaw and branchial arch mutants in zebrafish I: branchial arches. 1996

T F Schilling, and T Piotrowski, and H Grandel, and M Brand, and C P Heisenberg, and Y J Jiang, and D Beuchle, and M Hammerschmidt, and D A Kane, and M C Mullins, and F J van Eeden, and R N Kelsh, and M Furutani-Seiki, and M Granato, and P Haffter, and J Odenthal, and R M Warga, and T Trowe, and C Nüsslein-Volhard

Imperial Cancer Research Fund, London, UK. schillin@icrf.icnet.uk

Jaws and branchial arches together are a basic, segmented feature of the vertebrate head. Seven arches develop in the zebrafish embryo (Danio rerio), derived largely from neural crest cells that form the cartilaginous skeleton. In this and the following paper we describe the phenotypes of 109 arch mutants, focusing here on three classes that affect the posterior pharyngeal arches, including the hyoid and five gill-bearing arches. In lockjaw, the hyoid arch is strongly reduced and subsets of branchial arches do not develop. Mutants of a large second class, designated the flathead group, lack several adjacent branchial arches and their associated cartilages. Five alleles at the flathead locus all lead to larvae that lack arches 4-6. Among 34 other flathead group members complementation tests are incomplete, but at least six unique phenotypes can be distinguished. These all delete continuous stretches of adjacent branchial arches and unpaired cartilages in the ventral midline. Many show cell death in the midbrain, from which some neural crest precursors of the arches originate. lockjaw and a few mutants in the flathead group, including pistachio, affect both jaw cartilage and pigmentation, reflecting essential functions of these genes in at least two neural crest lineages. Mutants of a third class, including boxer, dackel and pincher, affect pectoral fins and axonal trajectories in the brain, as well as the arches. Their skeletal phenotypes suggest that they disrupt cartilage morphogenesis in all arches. Our results suggest that there are sets of genes that: (1) specify neural crest cells in groups of adjacent head segments, and (2) function in common genetic pathways in a variety of tissues including the brain, pectoral fins and pigment cells as well as pharyngeal arches.

UI	MeSH Term	Description	Entries
D007568	Jaw	Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.	Jaws
D008636	Mesencephalon	The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the PONS and the DIENCEPHALON. Midbrain contains two major parts, the dorsal TECTUM MESENCEPHALI and the ventral TEGMENTUM MESENCEPHALI, housing components of auditory, visual, and other sensorimoter systems.	Midbrain,Mesencephalons,Midbrains
D009055	Mouth	The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.	Oral Cavity,Cavitas Oris,Cavitas oris propria,Mouth Cavity Proper,Oral Cavity Proper,Vestibule Oris,Vestibule of the Mouth,Cavity, Oral
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009336	Necrosis	The death of cells in an organ or tissue due to disease, injury or failure of the blood supply.
D010614	Pharynx	A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).	Throat,Pharynxs,Throats
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D010858	Pigmentation	Coloration or discoloration of a part by a pigment.	Pigmentations
D001934	Branchial Region	A region, of SOMITE development period, that contains a number of paired arches, each with a mesodermal core lined by ectoderm and endoderm on the two sides. In lower aquatic vertebrates, branchial arches develop into GILLS. In higher vertebrates, the arches forms outpouchings and develop into structures of the head and neck. Separating the arches are the branchial clefts or grooves.	Branchial Arches,Branchial Clefts,Pharyngeal Arches,Visceral Arches,Branchial Arch,Branchial Grooves,Pharyngeal Arch,Pharyngeal Clefts,Pharyngeal Grooves,Visceral Arch,Arch, Branchial,Arch, Pharyngeal,Arch, Visceral,Arches, Branchial,Arches, Pharyngeal,Arches, Visceral,Archs, Pharyngeal,Branchial Cleft,Branchial Groove,Branchial Regions,Cleft, Branchial,Cleft, Pharyngeal,Clefts, Branchial,Clefts, Pharyngeal,Groove, Branchial,Groove, Pharyngeal,Grooves, Branchial,Grooves, Pharyngeal,Pharyngeal Archs,Pharyngeal Cleft,Pharyngeal Groove,Region, Branchial,Regions, Branchial
D005121	Extremities	The farthest or outermost projections of the body, such as the HAND and FOOT.	Limbs,Extremity,Limb