Mechanical strain regulation of the Chicken glypican-4 gene ...

LEGENDS TO FIGURES
Fig. 1. The assembly of the PCR products of the chicken GPC-4.
Fig. 2. Predicted amino acid sequence of the coding region of chicken GPC-4. Amino
acids are denoted by the single-letter code. Gray background represents identity in the
amino acids between the chicken and the mammalian genes. Open circles indicate cystein
residues that are conserved in all GPC members. The N-terminal signal and C-terminal
hydrophobic region are boxed. Glypican signature region is represented by a solid line.
Fig.3. In situ hybridization of ESG biopsies, taken at various intervals after oviposition
with the avian GPC-4 probe. (A) The egg resides in the isthmus; (B) 1 h, (C) 2 h, (D) 8 h,
(E) 12 h and (F) 17 h after the entry of the egg into the ESG. Magnification 20x.
Fig. 4. GPC-4 gene expression in the ESG. (A) Hematoxylin-Eosin staining. (B) In situ
hybridization with chicken GPC-4 specific probe. PE - pseudostratified epithelium, GE –
glandular epithelium.
Fig 5. Effect of mechanical strain on GPC-4 gene expression in the ESG. Mechanical
strain was applied when there were no egg in the ESG and the GPC-4 gene was not
expressed. (A) Control, no strain; (B) 3 h after mechanical strain induction; inflated
volume was 20 cm 3 , (C) 3 h after mechanical strain induction; inflated volume was 60
cm 3 . Magnification 20x.
Fig.6. Effect of mechanical strain withdrawal on GPC-4 gene expression. Premature
forced oviposition was performed in order to remove the mechanical strain imposed by
the resident egg at the time of maximal mechanical strain induction. (A) 2 h after
expulsion of the egg from the ESG; (B) Control, the egg is in the ESG, 9 h after
oviposition.
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