title: Correlated evolution of gonadotropin-releasing hormone and gonadotropin-inhibitory hormone and their receptors in mammals.
abstract: BACKGROUND
  Evolutionary rate variation in genes (proteins) is manifested both within the species (genome) and between the species (genomes). However, the interdependent components of a biological system in form of a gene or a protein are expected to evolve in a correlated manner under a common functional constraint.
  
  
  METHODS
  The phylogenetic analysis and correlation analysis of gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH) and their receptors (GnRHR and GnIHR) was conducted along with other control neuropeptides.
  
  
  RESULTS
  Both neuropeptides and their receptors regulating the reproductive neuroendocrine axis in vertebrates exhibited a correlated evolution under a common physiological constraint to regulate the release of gonadotropin. This result supports a coordinated substitution of amino acids in the GnRH and the GnIH neuropeptides along with their receptors in terms of similar evolutionary rates and distances with similar nucleotide composition of genes.
  
  
  CONCLUSIONS
  This is the first demonstration of the correlated evolution of two components of an endocrine system regulating the release of gonadotropin which are acting in concert for successful reproduction.
authors.affiliation: Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Pondicherry, India. basant68@email.com
authors.forename: Basant K
authors.initials: BK
authors.lastname: Tiwary
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics; D007028:Hypothalamic Hormones / Q000235:genetics; D008322:Mammals / Q000235:genetics; D010802:Phylogeny; D018013:Receptors, Neuropeptide / Q000235:genetics
chemical_list: D007028:Hypothalamic Hormones; D018013:Receptors, Neuropeptide; D007987:Gonadotropin-Releasing Hormone