Multiple ovarian transplants to rescue a transgenic line of mice

Archiving genetically altered animals: a review of cryopreservation and recovery methods for genome edited animals

With the ever-expanding numbers of genetically altered (GA) animals created in this new age of CRISPR/Cas, tools for helping the management of this vast and valuable resource are essential. Cryopreservation of embryos and germplasm of GA animals has been a widely used tool for many years now, allowing for the archiving, distribution and colony management of stock. However, each year brings an array of advances, improving survival rates of embryos, success rates of in-vitro fertilisation and the ability to better share lines and refine the methods to preserve them. This article will focus on the mouse field, referencing the latest developments and assessing their efficacy and ease of implementation, with a brief note on other common genetically altered species (rat, zebrafish, Xenopus, avian species and non-human Primates).

Cryopreservation and Transplantation of Laboratory Rodent Ovarian Tissue for Genome Banking and Biomedical Research

Genetic modifications in combination with highly sophisticated assisted reproductive technologies such as in vitro oocyte maturation and development, in vitro fertilization, intracytoplasmic sperm injection, and in vitro embryo culture have opened many research avenues and treatment options for both animals and humans. The number of genetically modified (GM) rodent strains increased considerably during the last several decades, and their numbers are expected to increase due to efficient gene editing technologies including the CRISPR/Cas9. Rodent ovarian tissues (OT) cryopreservation and transplantation procedures have several applications in biomedical field: they provide a fertility restoration option for GM rodent strains in some circumstances. They also serve as models to investigate OT cryopreservation as potential alternatives for human infertility patients as well as other domestic and wildlife species for the development of improved cryopreservation and subsequent transplantation strategies. The modeling studies enable determining effective cryoprotective agents (CPA), CPA and water permeability kinetics, and cooling and warming rates during the development of OT cryopreservation procedures. Furthermore, rodent models are extremely useful for determining post-thaw OT graft sites as well as potential medical interventions in an effort to expedite angiogenesis and inhibit inflammatory/immune response, OT longevity, and follicular integrity. Here we describe methodologies for rodent OT cryopreservation and potential transplantation sites for frozen-thawed rat and mouse OT.

Transplantation Into the Mouse Ovarian Fat Pad

Orthotopic transplantation assays in mice are invaluable for studies of cell regeneration and neoplastic transformation. Common approaches for orthotopic transplantation of ovarian surface and tubal epithelia include intraperitoneal and intrabursal administration of cells. The respective limitations of these methods include poorly defined location of injected cells and limited space volume. Furthermore, they are poorly suited for long-term structural preservation of transplanted organs. To address these challenges, we have developed an alternative approach, which is based on the introduction of cells and tissue fragments into the mouse fat pad. The mouse ovarian fat pad is located in the immediate vicinity of the ovary and uterine tube (aka oviduct, fallopian tube), and provides a familiar microenvironment for cells and tissues of these organs. In our approach fluorescence-labeled mouse and human cells, and fragments of the uterine tube are engrafted by using minimally traumatic dorsal incision surgery. Transplanted cells and their outgrowths are easily located in the ovarian fat pad for over 40 days. Long-term transplantation of the entire uterine tube allows correct preservation of all principle tissue components, and does not result in adverse side effects, such as fibrosis and inflammation. Our approach should be uniquely applicable for answering important biological questions such as differentiation, regenerative and neoplastic potential of specific cell populations. Furthermore, it should be suitable for studies of microenvironmental factors in normal development and cancer.