Efficient marmoset genome engineering by autologous embryo transfer and CRISPR/Cas9 technology.

Genetic engineering of non-human primates, which are most closely related to humans, has been expected to generate ideal animal models for human genetic diseases. The common marmoset (Callithrix jacchus) is a non-human primate species adequate for the production of genetically modified animals because of their small body size and high reproductive capacity. Autologous embryo transfer (AET) is routinely utilized in assisted reproductive technologies for humans but not for experimental animals.

Deletion of a Seminal Gene Cluster Reinforces a Crucial Role of SVS2 in Male Fertility.

Multiple genes, whose functions or expression are overlapping, compensate for the loss of one gene. A gene cluster in the mouse genome encodes five seminal vesicle proteins (SVS2, SVS3, SVS4, SVS5, and SVS6). These proteins are produced by male rodents and function in formation of the copulatory plug following mating.

Mapping of a responsible region for sex reversal upstream of Sox9 by production of mice with serial deletion in a genomic locus.

Sox9 plays critical roles in testis formation. By mapping four familial cases of disorders of sexual development, a 32.5 kb sequence located far upstream of SOX9 was previously identified as being a commonly deleted region and named the XY sex reversal region (XYSR).

A tandem repeat array in IG-DMR is essential for imprinting of paternal allele at the Dlk1-Dio3 domain during embryonic development.

Genomic imprinting is a phenomenon that causes parent-origin-specific monoallelic expression of a small subset of genes, known as imprinted genes, by parentally inherited epigenetic marks. Imprinted genes at the delta-like homolog 1 gene (Dlk1)-type III iodothyronine deiodinase gene (Dio3) imprinted domain, regulated by intergenic differentially methylated region (IG-DMR), are essential for normal development of late embryonic stages. Although the functions of IG-DMR have been reported by generating knockout mice, molecular details of the regulatory mechanisms are not fully understood as the specific sequence(s) of IG-DMR have not been identified.

CRISPR/Cas9-mediated simultaneous knockout of Dmrt1 and Dmrt3 does not recapitulate the 46,XY gonadal dysgenesis observed in 9p24.3 deletion patients.

DM domain transcription factors play important roles in sexual development in a wide variety of species from invertebrate to humans. Among seven mammalian family members of DM domain transcription factors, DMRT1 has been studied in mouse and human for its conserved role in male gonadal identity. Chromosomal deletion of 9p24.

Creation of mutant mice with megabase-sized deletions containing custom-designed breakpoints by means of the CRISPR/Cas9 system.

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system is a useful tool for creation of mutant mice with mutations mirroring those in human patients. Various methods have been developed for this purpose, including deletions, inversions, and translocations. So far, mutant mice with deletions of up to 1.

Deletion of conserved sequences in IG-DMR at Dlk1-Gtl2 locus suggests their involvement in expression of paternally expressed genes in mice.

Expression regulation of the Dlk1-Dio3 imprinted domain by the intergenic differentially methylated region (IG-DMR) is essential for normal embryonic development in mammals. In this study, we investigated conserved IG-DMR genomic sequences in eutherians to elucidate their role in genomic imprinting of the Dlk1-Dio3 domain. Using a comparative genomics approach, we identified three highly conserved sequences in IG-DMR.

The p.R92W variant of induces testicular development of 46,XX gonads in humans, but not in mice: phenotypic comparison of human patients and mutation-induced mice.

NR5A1 is the key regulator of adrenal and gonadal development in both humans and mice. Recently, a missense substitution in human , p.R92W, was shown to underlie gonadal dysgenesis in genetic males and testicular formation in genetic females.

Microinjection-based generation of mutant mice with a double mutation and a 0.5 Mb deletion in their genome by the CRISPR/Cas9 system.

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system is a useful tool for genome editing. In this study, using a microinjection-based CRISPR/Cas9 system, we efficiently generated mouse lines carrying mutations at the Irx3 and Irx5 loci, which are located in close proximity on a chromosome and are functionally redundant. During the generation of Irx3/Irx5 double mutant mice, a deletion of ~0.

Cord blood-derived endothelial colony-forming cell function is disrupted in congenital diaphragmatic hernia.

Vascular growth is necessary for normal lung development. Although endothelial progenitor cells (EPCs) play an important role in vascularization, little is known about EPC function in congenital diaphragmatic hernia (CDH), a severe neonatal condition that is associated with pulmonary hypoplasia. We hypothesized that the function of endothelial colony-forming cells (ECFCs), a type of EPC, is impaired in CDH.

Data supporting the role of Fyn in initiating myelination in the peripheral nervous system.

Transgenic mice, which express active Fyn tyrosine kinase under the control of a glial fibrillary acidic protein promoter, have been produced. This promoter induces protein expression in the initiation stage of myelination in the peripheral nervous system (PNS) "Phosphorylation of cytohesin-1 by Fyn is required for initiation of myelination and the extent of myelination during development (Yamauchi et al., 2015 [1])".

Utilization of the CRISPR/Cas9 system for the efficient production of mutant mice using crRNA/tracrRNA with Cas9 nickase and FokI-dCas9.

The CRISPR/Cas9 system is a powerful genome editing tool for the production of genetically modified animals. To produce mutant mice, chimeric single-guide RNA (sgRNA) is cloned in a plasmid vector and a mixture of sgRNA and Cas9 are microinjected into the fertilized eggs. An issue associated with gene manipulation using the CRISPR/Cas9 system is that there can be off-target effects.

Generation of mutant mice via the CRISPR/Cas9 system using FokI-dCas9.

Genome editing, which introduces mutations in genes of interest using artificial DNA nucleases such as the ZFN, TALEN, and CRISPR/Cas9 systems in living cells, is a useful tool for generating mutant animals. Although CRISPR/Cas9 provides advantages over the two other systems, such as an easier vector construction and high efficiency of genome editing, it raises concerns of off-target effects when single guide RNA (gRNA) is used. Recently, FokI-dCas9 (fCas9), a fusion protein comprised of the inactivated mutant form of Cas9 and the DNA nuclease domain of FokI, has been developed.

Rapid generation of mouse models with defined point mutations by the CRISPR/Cas9 system.

Introducing a point mutation is a fundamental method used to demonstrate the roles of particular nucleotides or amino acids in the genetic elements or proteins, and is widely used in in vitro experiments based on cultured cells and exogenously provided DNA. However, the in vivo application of this approach by modifying genomic loci is uncommon, partly due to its technical and temporal demands. This leaves many in vitro findings un-validated under in vivo conditions.

Production of Sry knockout mouse using TALEN via oocyte injection.

Recently developed transcription activator-like effector nuclease (TALEN) technology has enabled the creation of knockout mice, even for genes on the Y chromosome. In this study, we generated a knockout mouse for Sry, a sex-determining gene on the Y chromosome, using microinjection of TALEN RNA into pronuclear stage oocytes. As expected, the knockout mouse had female external and internal genitalia, a female level of blood testosterone and a female sexually dimorphic nucleus in the brain.