The cephalochordate amphioxus is the closest living invertebrate relative of the vertebrates. It is vertebrate-like in having a dorsal, hollow nerve cord, notochord, segmental muscles, pharyngeal gill slits and a post-anal tail that develops from a tail bud.

The anatomy of cephalochordates is considered vertebrate-like, but simpler, having a prototypical chordate body plan. Chordate synapomorphies, present in amphioxus and vertebrates, include a dorsal hollow nerve chord and notochord, pharyngeal slits, segmented muscles and gonads, post anal tail, and homologs of pronephric kidney, pituitary and ...

lochordates (compared to vertebrates) makes amphioxus an attractive model for studying chordate biology at the cellular and molecular levels. Here we describe the life cycle of amphioxus, and discuss the natural histories and habitats of the different species of amphioxus. We also describe their use as laboratory animal models, and discuss

2023年9月18日 · The anatomy of cephalochordates is considered vertebrate-like, but simpler, having a prototypical chordate body plan. Chordate synapomorphies, present in amphioxus and vertebrates, include a dorsal hollow nerve chord and notochord, pharyngeal slits, segmented muscles and gonads, post anal tail, and homologs of pronephric kidney, pituitary and ...

2023年9月18日 · Cephalochordates and tunicates represent the only two groups of invertebrate chordates, and extant cephalochordates – commonly known as amphioxus or lancelets – are considered the best proxy for...

2024年7月8日 · Here we reinterpret the morphology of Pikaia, providing evidence for a gut canal and, crucially, a dorsal nerve cord-a robust chordate synapomorphy. The identification of these structures underpins a new anatomical model of Pikaia that shows that this fossil was previously interpreted upside down.

Cephalochordates (amphioxus or lancelets): a model for understanding the evolution of chordate characters Cold Spring Harb Protoc . 2009 Sep;2009(9):pdb.emo130. doi: 10.1101/pdb.emo130.

These five features diagnose the chordates, and taken together, distinguish them from all other taxa. 1-Notochord The notochord is a slender rod that develops from the mesoderm in all chordates. It lies dorsal to the coelom but beneath and parallel to the central nervous system (brain and spinal cord).

Chordate characteristics 1- Notochord:-In vertebrate replaced by vertebral column, in other cases may be persist or lost 2- Nerve Cord: Single, hollow cord dorsal to the notochord modified in vertebrates into the central nervous system. 3-Gill pouch: Lost in the Most chordates and Become functional gill in fish and amphibian larvae 4- Post anal ...

As a basal Chordate, the Ciona model system presents a simple scaffold that recapitulates the basic blueprint of cardiac development in Chordates. Here we will focus on the development and cellular structure of the heart of the ascidian Ciona as …