Aim 1: To continue to provide a service that will microinject pronuclei of fertilized eggs with purified DNA constructs containing genes relevant to the pathogenesis of skin diseases, and implant injected cells into pseudopregnant recipients, to generate transgenic mice expressing genes relevant to the biology of skin diseases. The ability to generate transgenic mice in two different strains (FVB/N and C57BL/6 mice) is maintained to provide investigators optimal flexibility in creating experimental models.

Aim 2: To continue to provide a service that will transfect embryonic stem cells with targeted homologous recombination vectors for genes relevant to the pathogenesis of skin diseases, isolate ES cells carrying appropriate homologous recombination events, and inject these ES cells into blastocysts, toward the generation of targeted “knockout” mice. The ability to generate knockout mice in three different strains (129SvS4/Jae, C57BL/6 or BALB/c mice) is maintained to provide investigators optimal flexibility in creating experimental models.

Aim 3: To incorporate new methodologies into the study of the pathogenesis of skin diseases. These will include the generation of mice inducibly expressing genes, mice with conditional (inducible or tissue-specific) “knockouts”, and “knock-in” mice (in which endogenous sequences are replaced with foreign sequences). Significantly, these new methodologies will provide novel in vivo approaches for focusing on the role of desired molecules in specific cell types within the skin or at specific times during the pathogenesis of skin disease through the generation of tissue specific and inducible transgenic and knockout mice. We will also initiate a program to facilitate the study of healthy and diseased human skin in murine transplant models. This will involve the systematic grafting of samples of normal and diseased human skin onto mice as they become available. Engrafted mice will be provided to investigators for preliminary experiments. For more extensive studies investigators will be trained to enable them to generate their own engrafted mice.

Aim 4: To continue to provide education about experimental approaches involving transgenic mice that will assist HSDRC investigators in asking focused experimental questions using transgenic mouse technology. We will continue to 1) provide advice about the design of DNA constructs and targeting vectors, ES cell technology, and animal husbandry and 2) provide an opportunity for a small number of students, fellows and visiting scientists to participate in transgenic research, and 3) maintain the HSDRC web site as a source of information about the use of transgenic mice in skin disease research including a list of mouse strains available through the HSDRC core.