The Origination of Growth Hormone/Insulin-Like Growth Factor System: A Story From Ancient Basal Chordate Amphioxus

Abstract

The growth hormone/insulin-like growth factor (GH/IGF) system, also called the pituitary-liver axis, has a somatotrophic role in the body. Although the GH/IGF system has always been regarded as a vertebrate-specific endocrine system, its actual origin remained unknown for a long time. The basal chordate, amphioxus, occupies an evolutionary position between vertebrates and invertebrates. Impressively, most of the members of the GH/IGF system are present in the amphioxus. The GH-like molecule in the amphioxus is mainly expressed in Hatschek’s pit. It functions similarly to vertebrate GH and has a GH receptor-like binding partner. The amphioxus IGF-like peptide shows mitogenic activity and an expression pattern resembling that of vertebrate IGF-I. The receptor of IGF-like peptide and IGF binding protein (IGFBP) have also been demonstrated to exist in the amphioxus. These results reveal the origin of the gene families in the GH/IGF system, providing strong evidence that this system emerged in the amphioxus.

A Well-Established Gut Microbiota Enhances the Efficiency of Nutrient Metabolism and Improves the Growth Performance of Trachinotus ovatus

“…The hypothalamus secretes growth hormone-releasing hormone (GHRH) and somatostatin (SS) to regulate the synthesis and secretion of growth hormone (GH), which binds to the growth hormone receptor (GHR) on target cell via the blood circulation [45,46]. This combination stimulates liver secretion of insulin-like growth factor 1 (IGF1), which later binds to the IGF1 receptor (IGF1R) on target cells and ultimately stimulates cell proliferation and differentiation [47,48]. Although the present study involves the study of GHR, neither the release of GH nor the action of IGF1 is addressed.…”

Transcriptomic Analysis Provides Insights into Candidate Genes and Molecular Pathways Involved in Growth of Mytilus coruscus Larvae

“…Presently, extensive studies exist concerning genes pertinent to growth and development primarily within vertebrates and insects [15][16][17][18]. However, there is a notable scarcity of studies elucidating embryogenesis and larval development in this species and related ones.…”

Expressions of Insulin-like Growth Factor System among Different Breeds Impact Piglets’ Growth during Weaning

“…IGFs are mainly produced by the liver and then released into the bloodstream, where they bind to IGFBPs and are transported to the target organs. IGFs bind to specific IGF-Rs located on the cell surface to activate downstream signaling pathways to promote cell proliferation and differentiation [10]. In particular, the IGF system is vital in initiating the connection between nutrition and the postnatal growth and development of various tissues and organs through secretory, paracrine, and endocrine actions [11,12].…”