Localization of thymosin beta 4 to the neural tissues during the development of Xenopus laevis, as studied by in situ hybridization and immunohistochemistry

Brain Res Dev Brain Res. 1994 Jun 17;79(2):177-85. doi: 10.1016/0165-3806(94)90122-8.


Thymosin beta 4, a polypeptide of 5 kDa, is known to have capacity to regulate actin polymerization by binding to an actin monomer. Distribution of Xenopus laevis thymosin beta 4 (XT beta 4) in the developing Xenopus larva was examined by means of in situ hybridization and immunohistochemistry. Analysis with in situ hybridization revealed that XT beta 4 mRNA becomes gradually localized to the neural tissues, notochord and inner epidermis during neurula stages. Intense accumulation of XT beta 4 mRNA was observed in the ganglions of cranial nerves and in the dorsal region of the spinal cord from stage 26 and onwards. XT beta 4 immunoreactivity (XTI) was observed in larvas at all developmental stages later than stage 26, tail bud embryo. Immunoreactivity was initially distributed to the ganglion of cranial nerve V and Rohon-Beard cells. As the development progressed, the XTI appeared in other neuronal groups. By late tadpole stages (stages 42-47) the XTI was found in the pineal body, oculomotor and trochlear motoneurons of the midbrain, various neurons in the rhombencephalon, ganglions of cranial nerves V, VII/VIII and IX/X. In the spinal cord the XTI was observed in Rohon-Beard cells, dorsal root ganglion cells, motoneurons and other spinal cord neurons. Immunoreactivity was seen in both cell bodies and axons of the neurons. These findings suggest that thymosin beta 4 plays a role in the development of neurons, especially of sensory neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cranial Nerves / cytology
  • Cranial Nerves / growth & development
  • Ganglia / cytology
  • Ganglia / growth & development
  • Immunohistochemistry
  • In Situ Hybridization
  • Larva / physiology
  • Microfilament Proteins / metabolism*
  • Molecular Sequence Data
  • Nervous System / growth & development*
  • Nervous System / metabolism*
  • Retina / cytology
  • Retina / growth & development
  • Spinal Cord / cytology
  • Spinal Cord / growth & development
  • Thymosin / metabolism*
  • Xenopus laevis


  • Microfilament Proteins
  • thymosin beta(4)
  • Thymosin