SarB/NachJ

Stock number: 035347
Research areas: Research Tools

Description

The wild-derived M.m. domesticus pre-incipient inbred line SarB/NachJ may be used in crosses with common inbred strains to create multi-parent mouse mapping populations and for use as a source of natural phenotypic variation. This wild-derived strain is part of the Special Mouse Strains Resource (SMSR), which is supported by funding from the Office of Resource Infrastructure Programs, Office of the Director, National Institutes of Health under award number P40OD011102.

Detailed description

SarB/NachJ is one of three wild-derived lines (SARA, SARB, SARC) descended by sibling mating from a single pair of mice of the subspecies Mus musculus domesticus caught in 2013 in Saratoga Springs (SAR), New York. These wild-derived lines were trapped and bred by Dr. Michael Sheehan, a former postdoc in Dr. Michael Nachman's group at the University of California, Berkeley. These strains, along with the rest of the Nachman collection of wild-derived strains, provide a resource for studying natural phenotypic variation in a controlled laboratory setting and will also be useful for a broad range of evolutionary investigations. Ravesloot-Chavez et al. (PMID:40937719) found the pre-inbred ancestors of this strain to have increased colony forming units in the lung 21 days after tuberculosis infection and a high neutrophil count compared to C57BL/6J and other wild-derived lines. Karyotyping of spermatocyte cell spreads from both SarA and SarB found the standard 2n = 40 all-acrocentric karyotype. The 2024 published phenotypic assessment by Dumont et al. (PMID:38598567) found the average litter size of the SarA colony at JAX to be approximately 5 pups per litter but with a very broad diversity of litter sizes overall. SarA and SarB had lower platelet counts than most other inbred strains but higher platelet volume. In addition to more detailed phenotypic characterization, they also found more than 9MB of inserted sequence and more than 10MB of inserted sequence in SarB relative to C57BL/6J.

Development

The SarB/NachJ founders were trapped in year 2013 in Saratoga Springs (SAR), New York by Michael Sheehan, a postdoc in the lab of Dr. Michael Nachman at the University of California, Berkeley. A single pair of unrelated individuals was mated and the colony propagated through sib-sib mating. Mice from the colony were imported to Dr. Beth Dumont at The Jackson Laboratory in March 2019 at generation F14 making these pre-incipient inbreds. At F20, the colony will become an incipient inbred and will be renamed to SARB; at greater than F60 the colony will be fully inbred. Mice from the Dumont colony were transferred to The Jackson Laboratory Repository in February 2021.