The molecular evolution of vertebrate growth hormones: A pattern of near-stasis interrupted by sustained bursts of rapid change

1996 ◽  
Vol 43 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Michael Wallis
Keyword(s):  
Molecular Evolution ◽  
Rapid Change ◽  
Growth Hormones

scholarly journals Molecular evolution of GH in primates: characterisation of the GH genes from slow loris and marmoset defines an episode of rapid evolutionary change

2001 ◽  
Vol 26 (3) ◽  
pp. 249-258 ◽  
Author(s):  
OC Wallis ◽  
YP Zhang ◽  
M Wallis
Keyword(s):  
Molecular Evolution ◽  
New World ◽  
Rapid Change ◽  
Upstream Region ◽  
New World Monkeys ◽  
Hydrophobic Core ◽  
Slow Loris ◽  
Gh Gene ◽  
Synonymous Sites ◽  
Rate Of Substitution

Pituitary growth hormone (GH), like several other protein hormones, shows an unusual episodic pattern of molecular evolution in which sustained bursts of rapid change are imposed on long periods of very slow evolution (near-stasis). A marked period of rapid change occurred in the evolution of GH in primates or a primate ancestor, and gave rise to the species specificity that is characteristic of human GH. We have defined more precisely the position of this burst by cloning and sequencing the GH genes for a prosimian, the slow loris (Nycticebus pygmaeus) and a New World monkey, marmoset (Callithrix jacchus). Slow loris GH is very similar in sequence to pig GH, demonstrating that the period of rapid change occurred during primate evolution, after the separation of lines leading to prosimians and higher primates. The putative marmoset GH is similar in sequence to human GH, demonstrating that the accelerated evolution occurred before divergence of New World monkeys and Old World monkeys/apes. The burst of change was confined largely to coding sequence for mature GH, and is not marked in other components of the gene sequence including signal peptide, 5' upstream region and introns. A number of factors support the idea that this episode of rapid change was due to positive adaptive selection. Thus (1) there is no apparent loss of function of GH in man compared with non-primates, (2) after the episode of rapid change the rate of evolution fell towards the slow basal level that is seen for most mammalian GHs, (3) the accelerated rate of substitution for the exons of the GH gene significantly exceeds that for introns, and (4) the amino acids contributing to the hydrophobic core of GH are strongly conserved when higher primate and other GH sequences are compared, and for coding sequences other than that coding for hydrophobic core residues the rate of substitution for non-synonymous sites (K(A)) is significantly greater than that for synonymous sites (K(S)). In slow loris, as in most non-primate mammals, there is no evidence for duplication of the GH gene, but in marmoset, as in rhesus monkey and man, the putative GH gene is one of a cluster of closely related genes.

High time resolution enzyme cytochemistry of rod outer segment

1990 ◽  
Vol 48 (3) ◽  
pp. 878-879
Author(s):  
Takuma Saito ◽  
Toshihiro Takizawa
Keyword(s):  
Enzyme Activities ◽  
Outer Segment ◽  
Rapid Change ◽  
High Time Resolution ◽  
Visual Cell ◽  
Enzyme Cytochemistry ◽  
Activation Effect ◽  
Rod Outer Segment ◽  
Enzymatic Cascades ◽  
Rapid Drop

Cells and tissues live on a number of dynamic metabolic pathways, which are made up of sequential enzymatic cascades.Recent biochemical and physiological studies of vision research showed the importance of cGMP metabolism in the rod outer segment of visual cell, indicat ing that the photon activated rhodopsin exerts activation effect on the GTP binding protein, transducin, and this act ivated transducin further activates phosphodiesterase (PDEase) to result in a rapid drop in cGMP concentration in the cytoplasm of rod outer segment. This rapid drop of cGMP concentration exerts to close the ion channel on the plasma membrane and to stop of inward current brings hyperpolarization and evokes an action potential.These sequential change of enzyme activities, known as cGMP cascade, proceeds quite rapidly within msec order. Such a rapid change of enzyme activities, such as PDEase in rod outer segment, was not a matter of conventional histochemical invest igations.

Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher
Keyword(s):  
Cytochrome P450 ◽  
Molecular Evolution ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase ◽  
Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

Career Action Centre: The Health of Those Who Use It During Rapid Change

1999 ◽  
Author(s):  
J. M. McIntosh ◽  
C. A. Woodward ◽  
C. E. Cunningham ◽  
J. A. Brown ◽  
H. Shannon ◽  
...  
Keyword(s):  
Rapid Change

A Rapid Change in Pressure

2020 ◽  
Vol 382 (5) ◽  
pp. e8
Author(s):  
Kristin D’Silva ◽  
Anand Vaidya ◽  
James W. Smithy ◽  
William J. Anderson ◽  
Barbara Cockrill
Keyword(s):  
Rapid Change

Decreasing water pressure cues ‘bailout’ in seaweed-associated crustaceans

2020 ◽  
Vol 653 ◽  
pp. 121-129
Author(s):  
RB Taylor ◽  
S Patke
Keyword(s):  
Water Pressure ◽  
Rapid Change ◽  
Brown Seaweed ◽  
Model System ◽  
Rate Of Change ◽  
Suitable Habitat ◽  
Changing Light ◽  
Surface Increase ◽  
Reduced Water ◽  
Transparent Chamber

Small mobile crustaceans are abundant on seaweeds. Many of these crustaceans rapidly abandon their host if it is detached from the seafloor and floats towards the surface, but the trigger for this ‘bailout’ behaviour is unknown. We tested 2 potential cues, i.e. rapid change in light and rapid change in water pressure, using >1 mm epifauna on the brown seaweed Carpophyllum plumosum as a model system. Bailout occurred in response to reduced water pressure, but not to changing light, as (1) bailout occurred at similar rates in light and dark, (2) bailout occurred on the seafloor when water pressure was reduced within a transparent chamber by the equivalent of ~0.5 m depth or more, and (3) little bailout occurred when water pressure was held constant within the chamber while seaweeds were raised to the surface. Increase in pressure (simulating sinking) did not induce bailout. The rate of bailout increased with increasing magnitude of pressure reduction but was not influenced greatly by the rate of change of pressure within the range tested (up to an equivalent of 0.4 m depth s-1). The use of pressure rather than light as a cue for bailout is consistent with the need for seaweed-associated crustaceans to rapidly abandon a detached host and relocate to suitable habitat during both day and night.

Sign in / Sign up

Export Citation Format

Share Document