Open AccessIntracellular distribution of type II collagen mRNA and prolyl 4‐hydroxylase in embryonic avian corneal epithelia
Author(s) -
Hirsch Michelle S.,
Chang Karen,
Kao Winston W.Y.,
Svoboda Kathy K.H.
Publication year - 1996
Publication title -
the anatomical record
Language(s) - English
Resource type - Journals
eISSN - 1097-0185
pISSN - 0003-276X
DOI - 10.1002/(sici)1097-0185(199601)244:1<1::aid-ar1>3.0.co;2-7
Subject(s) - immunostaining , endoplasmic reticulum , cytoplasm , in situ hybridization , microbiology and biotechnology , biology , messenger rna , propidium iodide , staining , type iv collagen , chemistry , immunohistochemistry , extracellular matrix , biochemistry , laminin , immunology , apoptosis , programmed cell death , gene , genetics
Background The distribution of endoplasmic reticulum (ER) proteins and type II collagen mRNA in whole mount preparations of embryonic corneal epithelia was investigated. We asked, do transmission electron microscopy (TEM) and confocal microscopy of chick prolyl 4‐hydroxylase (CPH) show similar ER distributions as CPH is necessary for collagen biosynthesis? Methods The overall distribution of ER was analyzed by TEM. Collagen secreting ER was localized with antibodies to chick prolyl 4‐hydroxylase (CPH, CPH‐α, or CPH‐β subunits). Type II collagen mRNA distribution was determined by in situ hybridization. Results The ER localized with TEM, and immunohistochemistry using anti‐CPH antibodies, showed similar distribution patterns. Immunostaining for CPH and CPH‐β was prominent in both periderm and basal cells and also appeared to stain the periderm apical surface. CPH‐α was less intense, only localizing to ER regions. The basal cell CPH distribution appeared perinuclear in optical sections that contained nuclei, but occupied nearly all the cytoplasm in a reticular pattern above and below nuclei, similar to that seen with TEM cross‐sections. Epithelia double labeled with propidium iodide and CPH showed overlapping cytoplasmic staining. The distribution of type II collagen mRNA was similar to the ER staining pattern, appearing to represent a subset of total ER. Conclusions This study demonstrates that ER markers have a similar distribution as type II collagen mRNA in embryonic avian corneal epithelia. In addition the CPH subunits had distinct, but overlapping distributions, suggesting that they may act independently. © 1996 Wiley‐Liss, Inc.