Understanding the C57BL/6J Mouse Model: From Genetic Origins to Research Applications

Introduction to JAX and the C57BL/6J Model00:00:05

The webinar begins with an introduction to The Jackson Laboratory (JAX), a nonprofit biomedical research organization, and outlines the presentation's focus on the origins, genetics, and applications of the C57BL/6J mouse model.

Genetic Origins and Nomenclature00:02:49

The history of the C57BL/6J strain is traced back to Abbie Lathrop and C.C. Little, explaining how inbreeding removes genetic variability. The segment details strain nomenclature, distinguishing between parental lines, substrain designations, and provenance codes like 'J' for Jackson Laboratory.

Substrains and Genetic Stability00:09:56

This section explains how substrains arise through genetic drift and colony separation. It highlights JAX's Genetic Stability Program, where embryos are cryopreserved to lock the strain to a specific filial generation, preventing mutational accumulation over time.

Research Applications00:16:24

The presentation covers areas where C57BL/6J is widely used, including model generation due to its curated genome and drug addiction research, specifically regarding voluntary ethanol and cocaine consumption. It also discusses its use in aging research due to its relatively long lifespan.

Strain Integrity and Reproducibility00:30:53

The speaker discusses how genetic variability between vendors or colonies can impact research reproducibility. A case study involving GZMA knockout mice is presented to illustrate how contamination with different substrains (B6J vs B6N) can alter experimental phenotypes.

Strain Conditions and Irregularities00:36:32

Two common irregularities in C57BL/6J mice are discussed: malocclusion (overgrown incisors) and ocular issues such as microphthalmia and anophthalmia. The segment notes that JAX screens for these conditions to maintain colony health.

Colony Management and Conclusion00:39:02

The final section provides colony management recommendations, including breeding performance data and strategies for managing behaviors like barbering and alopecia. The talk concludes by summarizing the importance of strain awareness and the support JAX provides to researchers.