Transgenic Core

Bradford Lowell, MD, PhD

Director

Transgenic Facility, Director:    Joel Lawitts, PhD
Email: jlawitts@bidmc.harvard.edu

Transgenic Facility, Head Transgenic Technician:           Jennifer Mark
Email: jmark@bidmc.harvard.edu

The BADERC Transgenic Core is a fee-for-service facility that utilizes investigator-derived DNA/sgRNA reagents or investigator derived (or obtained) genetically modified embryonic stem cells to create founder transgenic and gene knockout or knockin mice (i.e. mice bearing point mutants, lox-modified or ires/2A-Cre knockin alleles) that can be used to address questions relevant to diabetes, endocrinology, obesity, and nutrition, including questions related to brain control of feeding, metabolism, and glucose homeostasis. 

The BIDMC Transgenic Facility, which performs the work of the BADERC Transgenic Core, is located within the Research North Building at 99 Brookline Ave.  It has been in existence since 1991 and has generated thousands of lines of mice which have been featured in many thousands of publications.  In 2017, the Core added an Easi-CRISPR service and has used this to efficiently and very rapidly generate >80 lines of genetically modified knockin mice (loxed alleles, Cre driver mice, etc.). 

The services offered by the BADERC Transgenic Core are listed below. 

Note, the availability of these services to BADERC members, and the pricing structure is contingent upon the BADERC P30 grant being funded (pending review, anticipated April, 2022).

Easi-CRISPR generation of gene knockout or gene knockin mice, mice bearing loxed alleles, recombinase driver mice, etc. 

Reagents, including DNA constructs, guide RNAs and Cas9 protein, are microinjected into fertilized one cell embryos. Tails from potentially modified founders are then provided to the investigator for genetic analysis.  Identified modified mice are then shipped to the investigator.  CRISPR reagents can be injected into FVB/N or C57BL/6 mouse embryos. Other strains are available upon request. 

Generation of Transgenic Mice

DNA transgenic constructs, supplied by the investigator, are microinjected into fertilized one cell embryos. Tails from potentially transgenic founders are then supplied to the investigator for genetic analysis. Identified founders are then shipped to the investigator.  Transgenes can be injected into FVB/N or C57BL/6 mouse embryos.  Other strains are available upon request. 

Generation of Chimeric Mice from Targeted ES Cells

Modified ES cells are injected into 3-day old embryos (blastocysts). Highly chimeric mice are then shipped to the investigator for breeding.  Targeted ES cell clones may have been generated by the BNORC Core (the BNORC Core has a larger budget and offers generation of targeted ES clones from DNA targeting constructs), by the investigator’s lab, or by various high-throughput ES targeting consortiums (one example being EUCOMM).

Cryopreservation of Mutant Mice

Fertilized one cell embryos are cryopreserved. 

Generating Mice from Frozen Embryos

Embryos frozen by outside sources or by the BADERC Transgenic Core will be thawed and transferred into pseudopregnant recipients. 

Note, mice can also be resurrected by frozen sperm, using the IVF service below.

In Vitro Fertilization (IVF). 

Sperm from mice the investigator wishes to propagate will be used to inseminate Facility-generated mouse eggs.  The strain of eggs used will match as closely as possible the strain of the sperm donor.  The fertilized embryos will be transferred into pseudopregnant recipients and the resulting live-born mice will be transferred to the investigator.  Donor sperm may have been acquired from mouse repositories (one example being MMRRC @ UCDavis), or from the investigator’s or a collaborator’s lab.  In the latter cases, the Facility will show investigators how to remove the tail of the male epididymis so that it can be brought to the Facility for harvesting of fresh donor sperm.