Synthetic Morphogenesis: introducing IEEE journal readers to programming living mammalian cells to make structures

Synthetic morphogenesis is a new engineering discipline, in which cells are genetically engineered to make designed shapes and structures. At least in this early phase of the field, devices tend to make use of natural shape-generating processes that operate in embryonic development, but invoke them artificially at times and in orders of a technologist’s choosing. This requires construction of genetic control, sequencing and feedback systems that have close parallels to electronic design, which is one reason the field may be of interest to readers of IEEE journals. The other reason is that synthetic morphogenesis allows the construction of two-way interfaces, especially opto-genetic and opto-electronic, between the living and the electronic, allowing unprecedented information flow and control between the two types of ‘machine’. This review introduces synthetic morphogenesis, illustrates what has been achieved, drawing parallels wherever possible between biology and electronics, and looks forward to likely next steps and challenges to be overcome

Connection of ES cell-derived collecting ducts and ureter-like structures to host kidneys in culture

Work toward renal generation generally aims either to introduce suspensions of stem cells into kidneys in the hope that they will rebuild damaged tissue, or to construct complete new kidneys from stem cells with the aim of transplanting the engineered organs. In principle, there might be a third approach; to engineer renal tissue ‘modules’ in vitro and to use them to replace sections of damaged host kidney. This approach would require the urine collecting system or ureter of the new tissues to connect to those of the host. In this report, we demonstrate a method that allows collecting duct trees or ureters, engineered from ES cells, to connect to the collecting duct system or ureter, respectively, of fetal kidneys in culture

Tamoxifen- and Mifepristone-Inducible Versions of CRISPR Effectors, Cas9 and Cpf1

Methods for making specific modifications to the genomes of living cells are powerful research tools. Two methods currently dominate, CRISPR and Cre recombinase. CRISPR has the advantage that it can act on unmodified target genes; Cre has the advantage of being available in drug-inducible versions, allowing temporal control, but it requires engineering (“floxing”) of the target gene. Here, we have combined these advantages by constructing drug (tamoxifen/mifepristone)-inducible Cas9 and Cpf1 CRISPR effectors. We demonstrate their low background activity and robust activation with drugs, by using gRNAs to target them to TetR, in a cell carrying a Tet-repressed reporter gene. As well as being useful in their own right, the research tools generated here will pave the way to making further drug-inducible effector proteins

FAK-Src signalling is important to renal collecting duct morphogenesis: discovery using a hierarchical screening technique

Summary This report describes a hierarchical screening technique for identification of pathways that control the morphogenesis of the renal collecting duct system. The multi-step screen involves a first round using a 2-dimensional, cell-line-based scrape-healing assay, then a second round using a 3-dimensional tubulogenesis assay; both of these rounds use new cell lines described in this report. The final stage is ex vivo organ culture. We demonstrate the utility of the screen by using it to identify the FAK–Src-pathway signalling as being important for collecting duct development, specifically for the cell proliferation on which this development depends