After ensuring the specificity of their pAb, Kolosov et al. determined the
of these TJ-associated proteins in a wide variety of larval lamprey tissues using
immunohistochemistry (Panels B – J).
Stunning immunofluorescence images of larval lamprey tissue using the anti-Ocln
pAb demonstrated clear immunoreactivity towards Ocln (red) across
various tissue sections. The transmembrane Na+/K+-ATPase is highlighted in
green, and DAPI staining of nuclei is in blue.
Ocln localization was observed within primary (arrows) and secondary gill filaments
as well as mucous cells (arrow heads) of the primary gill filament (Panels B, C, D
respectively). Expression was also detected in the tubular epithelial cells of the kidney (Panel
E), epithelial cells of the integumentary system (Panel F), the subapical region of columnar
epithelial cells (Panel G), as well as the anterior, middle, and posterior cross sections of the
GI tract (Panels H, I, J respectively).
The research team proceeded to successfully characterize the localization of Ocln-a and
Tric in a
similar manner. Taken together with quantification data of serum ion levels, carcass moisture
abundance and TJ-associated mRNA transcript abundance following larval sea lamprey acclimation
to ion poor water for all three proteins, this work provided new insight into the unique
osmoregulation abilities of basal vertebrates.