PUBLICATION

Morphologic transformation of the thymus in developing zebrafish

Authors
Lam, S.H., Chua, H.L., Gong, Z., Wen, Z., Lam, T.J. and Sin, Y.M.
ID
ZDB-PUB-020909-2
Date
2002
Source
Developmental Dynamics : an official publication of the American Association of Anatomists   225(1): 87-94 (Journal)
Registered Authors
Gong, Zhiyuan
Keywords
zebrafish development; thymus; morphologic transformation; cortex-medullary regionalization; recombination activating gene-1; T-cell receptor
MeSH Terms
  • Animals
  • Genes, RAG-1/genetics*
  • In Situ Hybridization
  • Models, Biological
  • Receptors, Antigen, T-Cell/metabolism
  • Software
  • Thymus Gland/cytology
  • Thymus Gland/embryology*
  • Time Factors
  • Zebrafish/embryology*
PubMed
12203724 Full text @ Dev. Dyn.
Abstract
The morphologic transformation of the developing zebrafish thymus from 1 week postfertilization (wpf) to 15 wpf is described. The thymus overall morphology changed from a small pouch-like shape at 1 wpf to a conical shape between 2 and 3 wpf before acquiring a more complex shape from 4 wpf onward. Rapid growth rate along the lateral axis at the region near the pharyngeal epithelium occurred between 1 and 2 wpf, whereas rapid growth rate along the dorsal-ventral axis occurred between 3 and 6 wpf. Expansion of thymocyte population beginning from 1 wpf became more evident by 2 to 3 wpf, as indicated by the apparent increase of different sizes of lymphocytes, recombination activating gene-1 (rag-1 ), and T-cell antigen receptor alpha chain constant region (TCRAC) - positive cells. Tissue section in situ hybridization (ISH) analysis with rag-1 probe reveals that cortex-medullary regionalization has begun between 1 and 2 wpf as rag-1 expression clearly demarcated the cortex, whereas the medulla was rag-1 negative. The presence of TCRAC-positive cells in the medulla by 2-3 wpf, suggests that the thymic selection processes had begun. The zebrafish thymus is morphologically mature by 3 wpf. Early signs of thymic involution were observed in zebrafish aged 15 wpf.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping