The morphogenetic process in which an epithelium narrows along one axis and lengthens in a perpendicular axis usually resulting in the formation of the three primary germ layers, ectoderm, mesoderm and endoderm.

The morphogenetic process in which an epithelium narrows along one axis and lengthens in a perpendicular axis contributing to the lengthening of the axis of an organism.

Catalysis of the reaction: L-Selenomethionine + H2O => Methaneselenol + Ammonia + 2-oxobutanoic acid.

Catalysis of the reaction: ATP + L-Selenomethionine + H2O => Orthophosphate + Diphosphate + Se-Adenosylselenomethionine.

Catalysis of the reaction: R + Se-Adenosylselenomethionine => CH3-R + Se-Adenosyl-L-selenohomocysteine.

Catalysis of the reaction: Se-Adenosyl-L-selenohomocysteine + H2O => Adenosine + Selenohomocysteine.

Catalysis of the reaction: L-Serine + Selenohomocysteine => L-Selenocystathionine + H2O.

Catalysis of the reaction: L-Selenocystathionine + H2O => L-Selenocysteine + NH3 + 2-Oxobutanoic acid.

Catalysis of the reaction: Se-Methyl-L-selenocysteine + H2O => pyruvic acid + NH3 + Methaneselenol.

Catalysis of the reaction: methylselenol + H2O => H2Se + CH3OH.

The biological process whose specific outcome is the progression of the roof of the mouth from an initial condition to its mature state. This process begins with the formation of the structure and ends with the mature structure. The roof of the mouth is the partition that separates the nasal and oral cavities.

The biological process whose specific outcome is the progression of the hard palate from an initial condition to its mature state. This process begins with the formation of the structure and ends with the mature structure, whatever form that may be including its natural destruction. The hard palate is the anterior portion of the palate consisting of bone and mucous membranes.

The process in which neuroepithelial cells of the neural tube give rise to Brgmann glial cells, specialized bipotential progenitors cells of the cerebellum. Differentiation includes the processes involved in commitment of a cell to a specific fate.

The assembly and arrangement of a vacuole within a cell of the notochord.

The process whose specific outcome is the progression of the pharyngeal system over time, from its formation to the mature structure. The pharyngeal system is a transient embryonic complex that is specific to vertebrates. It comprises the pharyngeal arches, bulges of tissues of mesoderm and neural crest derivation through which pass nerves and pharyngeal arch arteries. The arches are separated internally by pharyngeal pouches, evaginations of foregut endoderm, and externally by pharyngeal clefts, invaginations of surface ectoderm. The development of the system ends when the stucture it contributes to are forming: the thymus, thyroid, parathyroids, maxilla, mandible, aortic arch, cardiac outflow tract, external and middle ear.

The process in which relatively unspecialized cells acquire specialized structural and/or functional features cells that make up the notochord. Differentiation includes the processes involved in commitment of a cell to a notochord cell fate.

The process whose specific outcome is the progression of a notochord cell over time, from its formation to its mature structure. Cell development does not include the steps involved in committing a cell to a specific fate.

The expansion of a cardiac muscle cell population by cell division.

The process whose specific outcome is the progression of the pericardium over time, from its formation to the mature structure. The pericardium is a double-walled sac that contains the heart and the roots of the aorta, vena cava and the pulmonary artery.