Evolution of Hormones

Searching Google for "evolution of hormones" revealed 20,800,000 references.      
Searching PubMed for "evolution of hormones" revealed 9,673 references: 

Gonadotropin-releasing hormone genes: phylogeny, structure, and functions (Goog) 

    (PDF Download Available)   
 from the Abstract:   
Gonadotropin-releasing hormone (GnRH, previously called leutinizing hormone-releasing hormone, LHRH) is the final common signaling molecule used by the brain to regulate reproduction in all vertebrates.  
    Recently, genes encoding two other GnRH forms have been discovered. Here we present a phylogenetic analysis that shows that the GnRH genes fall naturally into three distinct branches, each of which shares not only a molecular signature but also characteristic expression sites in the brain. The GnRH genes appear to have arisen through gene duplication from a single ancestral GnRH whose origin predates vertebrates. Several lines of data support this suggestion, including the fact that all three genes share an identical exonic structure. The existence of three distinct GnRH families suggests a new, natural nomenclature for the genes, and in addition, we present a logical proposal for naming the peptide sequences. The two recently discovered GnRH genes are unusual because they encode decapeptides that are identical in all the species in which they have been found. The control of gene expression also differs among the three gene families as might be expected since they have had separate evolutionary trajectories for perhaps 500 million years."      

Molecular evolution of the growth hormone-releasing hormone (Goog) 
Full length PDF available online.  Must download to copy. 
from the Abstract:       
     "Growth hormone-releasing hormone (GHRH) and pituitary adenylate cyclase-activating  polypeptide (PACAP) belong to the same superfamily of regulatory neuropeptides and have both been characterized on the basis of their hypophysiotropic activities.  
    This review describes the molecular
evolution of the GHRH/PACAP gene family from urochordates to mammals and presents the hypothesis that the respective roles of GHRH and PACAP in the control of GH secretion are totally inverted in phylogenetically distant groups of vertebrates.  
mammals, GHRH and PACAP originate from distinct precursors whereas, in all submammaliantaxa investigated so far, including birds, amphibians and fish, a single precursor encompasses a GHRH-like peptide and PACAP.   In  mammals, GHRHcontaining neurons are confined to the infundibular and dorsomedial nuclei of the hypothalamus while PACAP-producing neurons are widely distributed in hypothalamic and extrahypothalamic areas. In fish, both GHRH- and PACAP-immunoreactive neurons are restricted to the diencephalon and directly innervate the adenohypophysis. In mammals and birds, GHRH plays a predominant role in the control of GH secretion. In amphibians, both GHRH and PACAP are potent stimulators of GH release. In fish, PACAP strongly activates GH release whereas GHRH has  little or no effect on GH secretion. The GHRH/PACAP family of peptides thus provides a unique model in which to investigate the structural and functional facets of evolution."   

Estrogen Is the Most Ancient of Hormones (Goog)
Full length article available online. 
     For starters, the title is misleading.  The author really means that estrogen is the most ancient steriod hormone, not the most ancient hormone of all. 
     "By reconstructing a DNA sequence that existed more than 450 million years ago, Joe Thornton, a research scientist and evolutionary biologist at Columbia's Earth Institute, has revealed how new hormones emerged during evolution..." 
     "Thornton studied steroid receptors present in lamprey -- jawless fish that diverged from the rest of the vertebrate lineage about 450 million years ago. ... lampreys have just three of the six hormone receptors that are found in humans and other jawed vertebrates – an estrogen receptor, a progesterone receptor, and a single corticoid receptor, but no androgen receptor." 
     "Steroid hormones are produced in a common biochemical pathway in which progesterone is converted to testosterone, which is then transformed into estrogen. Thornton's results showed that the last hormone in the pathway was the first to have a receptor,
     ..it implied that less ancient steroid hormones – progesterone and testosterone in particular – had been present as biochemical intermediates before the receptors that recognize them evolved.    
    ... the hormones came first, but they had weren't hormones and had no function per se, until their receptor partners emerged in the vertebrate genome," 

Episodic Evolution of Protein Hormones in Mammals (PubMed) 
Only the abstract is available online.  I haven't yet obtained the PDF. 
Based on the sequences currently available, and pooling data from all eight proteins, the phase of slow basal change occupied about 85% of the sampled evolutionary time, but most evolutionary change (about 62% of the substitutions accepted) occurred during the episodes of rapid change.  
    It is concluded that, in mammals at least, a pattern of prolonged periods of near-stasis with occasional episodes of rapid change provides a better model of evolutionary change for protein hormones than the one of constant evolutionary rates that is commonly favored. The mechanisms underlying this episodic evolution are not yet clear, and it may be that they vary from one group to another; in some cases, positive selection appears to underlie bursts of rapid change. Where gene duplication is associated with a period of accelerated evolution this often occurs at the end rather than the beginning of the episode. To what extent the type of pattern seen for protein hormones can be extended to other proteins remains to be established."  

Hormone evolution: The key to signalling (Goog) 
Only a very short description is available online.  I haven't yet obtained the PDF. 
     "Cells of multicellular organisms need to communicate with each other to regulate their development and organize growth and cell division. Hormones contribute to these processes by acting as messengers between cells, telling them what's happening elsewhere and how they should respond." 

Hormone signaling in evolution and development: a non-model system approach (Goog)
Only the abstract is available online.  I haven't yet obtained the PDF. 
     "Thyroid hormones (TH) regulate a variety of functions such as growth, development and metabolism. In addition, increasing levels of the thyroid hormones (TH) T3 and T4 promote metamorphosis in amphibians, via binding to nuclear hormone receptors.  In contrast, jawless fish (lampreys) require a critical time period during which TH is absent in order to undergo the metamorphic transition"   

Endocrinology of protochordates - Canadian Journal of Zoology 
Large-scale gene duplications occurred early in the vertebrate lineage after the split with protochordates. Thus, protochordate hormones and their receptors, transcription factors, and signaling pathways may be the foundation for the endocrine system in vertebrates. A number of hormones have been identified including cionin, a likely ancestor of cholecytokinin (CCK) and gastrin. Both insulin and insulin-like growth hormone (IGF) have been identified in separate cDNAs in a tunicate, whereas only a single insulin-like peptide was found in amphioxus. In tunicates, nine distinct forms of gonadotropin-releasing hormone (GnRH) are shown to induce gamete release, even though a pituitary gland and sex steroids are lacking. In both tunicates and amphioxus, there is evidence of some components of a thyroid system, but the lack of a sequenced genome for amphioxus has slowed progress in the structural identification of its hormones. Immunocytochemistry has been used to tentatively identify a number of hormones in protochordates, but structural and functional studies are needed. For receptors, protochordates have many vertebrate homologs of nuclear receptors, such as the thyroid, retinoic acid, and retinoid X receptors. Also, tunicates have cell surface receptors including the G-protein-coupled type, such as β-adrenergic, putative endocannabinoid, cionin (CCK-like), and two GnRH receptors. Several tyrosine kinase receptors include two epidermal growth factor (EGF) receptors (tunicates) and an insulin/IGF receptor (amphioxus). Interestingly, neither steroid receptors nor a full complement of enzymes for synthesis of sex steroids are encoded in the Ciona genome. Tunicates appear to have some but not all of the necessary molecules to develop a vertebrate-like pituitary or complete thyroid system.  "  

The dawn and evolution of hormones in the adenohypophysis (Goog) 
Only the abstract is available online.  I haven't yet obtained the PDF. 
     "The adenohypophysial hormones have been believed to have evolved from several ancestral genes by duplication followed by evolutionary divergence... we have characterized adenohypophysial hormones in an agnathan, the sea lamprey Petromyzon marinus ... the rostral pars distalis (RPD) and the pars intermedia (PI)... the final products from both tissues are the same in all vertebrates, i.e., ACTH from the PD and MSH from the PI. ... Sea lamprey growth hormone (GH) ... is the ancestral hormone of the GH family ... The other member of the gene family, PRL and SL, appeared by gene duplication. ... lampreys have a single GTH gene, which duplicated after the agnathans and prior to the evolution of gnathostomes to give rise to LH and FSH." 

Evolution of Metamorphosis: Role of Environment on Expression of Mutant Nuclear Receptors
Click to download the full-length PDF. 
from the Abstract:     
    "Various lipophilic signals, including ecdysone, retinoic acid, estradiol, cortisol, testosterone and progesterone, act through nuclear receptors, a large group of transcription factors that regulate differentiation and development, which are central to metamorphosis. Here, we focus on environmental factors (e.g. climate, chemicals) in the evolution of nuclear receptors and other signal transduction proteins that interact with heat shock protein 90 (Hsp90), a chaperone that promotes the proper folding and trafficking in cells of proteins. Hsp90 also promotes functional folding of some mutant signal proteins, which would be otherwise destabilized. Stress diverts Hsp90 from stabilizing mutant signal transduction proteins and towards promoting proper folding of stress-damaged proteins and preventing the aggregation of denatured proteins. Reduced Hsp90 levels allow expression of cryptic mutations in signal transduction proteins and new developmental patterns. Thus, environmental stress in the form of extreme climate can influence the evolution of metamorphosis.  
    We discuss how extreme cooling called “Snowball Earth”, which occurred in the
late Proterozoic, diverted Hsp90 from chaperoning signal-transduction proteins. As a result, preexisting mutant signal transduction-proteins were expressed in animals. Some mutations were selectively advantageous in animals that are seen in the Cambrian, when diverse pathways for metamorphosis in metazoans first appear in the fossil record. Other environmental factors, such as biological chemicals (e.g. the antibiotic geldanamycin) can reduce the levels of active HSP90 providing another mechanism for the emergence of mutant signaling pathways." 
 from the PDF
    "The Hsp90 complex promotes the proper folding and intracellular location of a variety of signal transduction proteins that are not functional in the absence of Hsp90. Some of these proteins are ligand-dependent transcription factors, such as nuclear receptors (e.g. EcR, RAR, AR, ER, GR, MR, PR) and the aryl hydrocarbon receptor; others, such as MyoD and mutated p53, are ligand-independent transcription factors. Hsp90 also stabilizes tyrosine kinases and serine/threonine kinases that act in the mitogen-actived protein (MAP) pathway"

Amphioxus, a Primitive Chordate, Is on Steroids: Evidence for Sex Steroids  (Goog). 
     See:  Amphioxus Hormones .   

Evolutionary roots of iodine and thyroid hormones (Goog) 
Abstract only online.  I have PDF.
    "Iodine is known to be crucial for life in many unicellular organisms (including evolutionarily ancient cyanobacteria), in part, because it acts as a powerful antioxidant." 
    "From an initial role as membrane antioxidant and biochemical catalyst, spontaneous coupling of iodine with tyrosine appears to have created a versatile, highly reactive and mobile molecule, which over time became integrated into the machinery of energy production, gene function, and DNA replication in mitochondria.  Iodotyrosines later coupled together to form
thyroid hormones (THs), the ubiquitous cell-signaling molecules used by all vertebrates." 
    "Protochordates, such as amphioxus (Branchiostoma sp.) and ascidians (sea-squirts), also possess an endostyle that synthesizes both iodotyrosines and THs. While the endostyle of adult amphioxus has been shown to integrate iodinated compounds into a specialized mucoprotein used in feeding, it has recently been demonstrated that metamorphosis is regulated by triiodothyroacetic acid, a TH derivative produced by the endostyle of the larva." 
    My comment
    Since this article does not explicitly mention any interactions between THs and neurons, it appears that this is not an interface between the endocrine and nervous systems. 

2011    18<73   
Emergence and evolution of the glycoprotein hormone and neurotrophin gene families in vertebrates. 
    See:  Amphioxus Pituitary

Convergence of hormones and autoinducers ... (Goog-PubMed) 
     See:  Prokaryote Colonies 

N-Acyl homoserine lactone (Wiki) 
     See:  Prokaryote Colonies 

Hormone fatty acid modifications: Gram negative bacteria and vertebrates demonstrate common structure and function (Goog)
Only the abstract is available online.  I haven't yet obtained the PDF. 
     See:  Prokaryote Colonies 

Searching Google for "pheromone" found 444,000 references: 

Pheromone (Goog-Wiki) 
A pheromone (from Ancient Greek φέρω phero "to bear" and hormone, from Ancient Greek ὁρμή "impetus") is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual.[1] There are alarm pheromones, food trail pheromones, sex pheromones, and many others that affect behavior or physiology. Pheromones are used from basic unicellular prokaryotes to complex multicellular eukaryotes.[2] Their use among insects has been particularly well documented. In addition, some vertebrates and plants communicate by using pheromones. 


CotA: Evolution of Hormones   
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