A vesicular glutamate transporter in lampreys: cDNA cloning and early expression in the nervous system

J Chem Neuroanat. 2010 Sep;40(1):71-81. doi: 10.1016/j.jchemneu.2010.03.009. Epub 2010 Apr 2.

Abstract

Vesicular glutamate transporters (VGLUTs) accumulate glutamate into synaptic vesicles of glutamatergic neurons, and thus are considered to define the phenotype of these neurons. Glutamate also appears to play a role in the development of the nervous system of vertebrates. Here we report the characterization of a vesicular glutamate transporter of lamprey (lVGluT), a novel member of the VGluT gene family. Phylogenetic analysis indicates that lVGLUT cannot be assigned to any of the three VGLUT isoforms characterized in teleosts and mammals, suggesting that these classes may have been fixed after the splitting between cyclostomes and gnathostomes. Expression pattern analysis during lamprey embryogenesis and prolarval stages shows that lVGluT expression is restricted to the nervous system. The first structure to express lVGluT was the olfactory epithelium of late embryos. In the brain of early prolarvae, lVGluT was expressed in most of the neuronal populations that generate the early axonal scaffold. lVGluT expression was also observed in neuronal populations of the rhombencephalon and spinal cord and in ganglia of the branchiomeric, octaval and posterior lateral line nerves. In the rhombencephalon, lVGluT expression appears to be spatially restricted in dorsal and ventral longitudinal domains. Comparison of the early expression of VGluT genes between the lamprey and some anamniotan gnathostomes (frog, zebrafish) reveals a conserved expression pattern, likely to reflect ancestral vertebrate characteristics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / cytology
  • Brain / embryology
  • Brain / metabolism
  • Cloning, Molecular
  • Cranial Nerves / cytology
  • Cranial Nerves / embryology
  • Cranial Nerves / metabolism
  • DNA, Complementary / genetics*
  • Evolution, Molecular
  • Female
  • Ganglia, Sensory / cytology
  • Ganglia, Sensory / embryology
  • Ganglia, Sensory / metabolism
  • Gene Expression Regulation, Developmental / genetics
  • Growth Cones / metabolism
  • Growth Cones / ultrastructure
  • Lateral Line System / cytology
  • Lateral Line System / embryology
  • Lateral Line System / metabolism
  • Male
  • Molecular Sequence Data
  • Nervous System / cytology
  • Nervous System / embryology
  • Nervous System / metabolism*
  • Neurogenesis / genetics
  • Neurons / cytology
  • Neurons / metabolism*
  • Petromyzon / embryology
  • Petromyzon / metabolism*
  • Phylogeny
  • Sequence Analysis, Protein
  • Sequence Homology, Amino Acid
  • Spinal Cord / cytology
  • Spinal Cord / embryology
  • Spinal Cord / metabolism
  • Vesicular Glutamate Transport Proteins / genetics*
  • Vesicular Glutamate Transport Proteins / isolation & purification

Substances

  • DNA, Complementary
  • Vesicular Glutamate Transport Proteins