This month we will look into a protein expressed in testis called lamin B receptor (LBR). The analysis was performed with the new multiplex immunohistochemistry technique, which allowed us to characterize when and where proteins are expressed during spermatogenesis - the development of sperm. More in depth information about the technique can be found here!

Multiplex immunohistochemistry (mIHC/IF) allows for simultaneous spatial visualization of different proteins in a single tissue section. The mIHC technique can aid in identifying cell types that require co-expression of two or several markers and also enables the characterization of proteins expressed in subsets of cell types or cell states. In the latest version of the HPA, mIHC antibody panels were used to study poorly characterized testis proteins throughout spermatogonium and spermatocyte development and differentiation.

LBR is a receptor found (among other cell types) in the nuclear membrane of the spermatogonia, more specifically in state 0 and state 1 of the spermatogonium development, which correspond to spermatogonial stem cell states. LBR is believed to be involved in cholesterol biosynthesis and the anchoring of lamina and heterochromatin to the inner membrane of the nuclear envelope. Mutations in this gene have been associated with development of skeletal dysplasia, or dwarfism, which is a rare genetic disease that will eventually cause abnormal growth in bone tissue. The function of LBR in testis is yet to be studied.