Genome engineering through CRISPR/Cas9 technology in the human germline and pluripotent stem cells.

Background: With the recent development of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 genome editing technology, the possibility to genetically manipulate the human germline (gametes and embryos) has become a distinct technical possibility. Although many technical challenges still need to be overcome in order to achieve adequate efficiency and precision of the technology in human embryos, the path leading to genome editing has never been simpler, more affordable, and widespread.

Objective And Rationale: In this narrative review we seek to understand the possible impact of CRISR/Cas9 technology on human reproduction from the technical and ethical point of view, and suggest a course of action for the scientific community.

Efficient delivery and functional expression of transfected modified mRNA in human embryonic stem cell-derived retinal pigmented epithelial cells.

Gene- and cell-based therapies are promising strategies for the treatment of degenerative retinal diseases such as age-related macular degeneration, Stargardt disease, and retinitis pigmentosa. Cellular engineering before transplantation may allow the delivery of cellular factors that can promote functional improvements, such as increased engraftment or survival of transplanted cells. A current challenge in traditional DNA-based vector transfection is to find a delivery system that is both safe and efficient, but using mRNA as an alternative to DNA can circumvent these major roadblocks.

Lower force and impaired performance during high-intensity electrical stimulation in skeletal muscle of GAMT-deficient knockout mice.

Force characteristics of skeletal muscle of knockout mice lacking creatine (Cr) due to a deletion of guanidinoacetate methyltransferase (GAMT) were studied in situ. Medial gastrocnemius muscles of anesthetized GAMT-deficient (GAMT-/-) and control (Con) littermates were stimulated at optimum length via the sciatic nerve at different stimulation frequencies (60-250 Hz). GAMT-/- mice showed reduced maximal tetanic and twitch force, reduced relative force at 60 Hz, and increased relaxation times.

Severely altered guanidino compound levels, disturbed body weight homeostasis and impaired fertility in a mouse model of guanidinoacetate N-methyltransferase (GAMT) deficiency.

We generated a knockout mouse model for guanidinoacetate N-methyltransferase (GAMT) deficiency (MIM 601240), the first discovered human creatine deficiency syndrome, by gene targeting in embryonic stem cells. Disruption of the open reading frame of the murine GAMT gene in the first exon resulted in the elimination of 210 of the 237 amino acids present in mGAMT. The creation of an mGAMT null allele was verified at the genetic, RNA and protein levels.