For further examination and staging of development of the thoracic bud, including the neural complex, we also analyzed timing of the appearance of ciliation in the endostyle and ciliated funnel by the presence of acetylated tubulin (Fig.
From studies based primarily on the unitary stolidobranch Styela clava, Ermak (1982) reported renewing cell populations in various epithelia including those of the ciliated funnel, endostyle, stigmata, esophagus, and stomach; these are areas in which proliferation was also noted in D.
Endostyle rudiment as a large evagination of inner vesicle opposite to dorsal hollow tube.
It is commonly considered that the endostyle of lower chordates may be a homolog and primitive antecedent of the vertebrate thyroid gland, mainly because the organ incorporates iodine (Barrington, 1957, 1958; Salvatore, 1969).
In addition, lower chordates (including tunicates, amphioxus, and lampreys) share an endostyle.
Coincidently with this change in the mode of larval locomotion, most of the primitive chordates or chordate ancestors may have shifted their feeding system to the use of pharyngeal gill slits for extracting suspended food from the water and of an endostyle for secreting mucus to catch the food particles (e.