Expression pattern of PRDM family using tissue clearing technique in mouse micro-embryo

Abstract

The proteins member of the PRDM family are known to have a potential role in tumor suppression, as well as in other diseases. Thus, elucidating the expression patterns of these PRDM proteins by high resolution analysis is necessary to future determine to characterize their biological role. Recent development in tissue clearing methods such as CLARITY (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/Immunostaining/In situhybridization-compatible Tissue hYdrogel) has allowed for three-dimensional analyses of biological structures as a whole, intact tissue, providing greater understanding of spatial relationships and biological circuits. Nonetheless, studies have reported issues when it comes to maintain structural integrity and preventing tissue disintegration, discouraging the application of these techniques with fragile tissues such as developing embryos. Here, we present an optimized passive clearing technique, mPACT-A (modified PACT-Acrylamide), which improves tissue rigidity without the detriment to 2 optical transparency. The mPACT-A protocol is specifically optimized for handling mouse embryos, which are small and fragile and get easily dismantled when processed with established tissue clearing methods. We demonstrated the feasibility of this technique by investigating the expression of relatively understudied PRDM proteins, PRDM7, 8, 12 and 13, in intact cleared mouse embryos at different stages of development. We observed strong PRDM7, 8, 12 and 13 expression in the developing mouse nervous system in various development stages of the mouse embryos. These results suggest potential roles for the PRDM proteins in neural development, that should be tested in future functional studies.