Cross references: Amphioxus Hormones Endostyle = Thyroid
Amphioxus Gut Hormones Lamellar Body = Pineal Gland Amphioxus Pituitary
Amphioxus Gonads Amphioxus Oxytocin Amphioxus Genomics
Stress ACTH Cortisol Glucocorticoid Stress Evolution
Stress hormone (Wiki)
This article on human stress hormones is provided for reference.
The amphioxus genome illuminates vertebrate origins and cephalochordate biology
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"The primary vertebrate endocrine organs (pineal gland, ovary, testis, endostyle/thyroid, brain, gut, and pituitary) have structurally simpler homologs in amphioxus."
"The stress response in vertebrates depends on the adrenal medulla for epinephrine and on the adrenal cortex for cortisol. Adrenal cortex function in vertebrates is controlled by the brain (corticotropin-releasing hormone, CRH) and pituitary ACTH. Although amphioxus lacks a discrete adrenal gland, it possesses genes for catecholamine synthesis and for adrenergic receptors, suggesting that some cells may synthesize epinephrine.
However, most of the stress-response genes (CRH, ACTH, ACTH receptor, cortisol and its receptor) are missing in amphioxus and have not been found in either Ciona or sea urchins. In addition, amphioxus also lacks a gene for the enzyme 21-hydroxylase (CYP21), necessary to synthesize cortisol precursors ... The only component present in all three invertebrates is similar to the CRH receptor."
For more from this paper, see: Amphioxus Genomics .