These mice carry a targeted mutation in the fibronectin 1 gene identical to that found in Stock No. <a href="https://www.jax.org/strain/002270">002270</a>. 
This line, backcrossed more than 13 times to C57BL/6J in the donating investigator's colony, has been used in a search for cardiac development modifier genes demonstrating phenotypic differences on C57BL/6J and 129S4/SvJae genetic backgrounds (Astrof, 2007). 
In the majority of 129S4 background homozygous targeted mutant embryos, heart progenitors remain at their anterior bilateral positions and fail to fuse at the midline to form a heart tube. However, on the C57BL/6J genetic background, cardiac development progresses further and results in a centrally-positioned looped heart. 
Linkage analysis led to the identification of a 1-Mbp interval on mouse Chromosome 4 containing 21 genes, including five that are differentially expressed between C57BL/6J and 129S4/SvJae. 
This strain may be helpful in studies of cardiac development.

These mice, carrying a targeted mutation of the fibronectin 1 gene (Fn1), have been used in a search for cardiac development modifier genes demonstrating phenotypic differences on C57BL/6J and 129S4/SvJae genetic backgrounds (Astrof 2007). On the C57BL/6J genetic background, cardiac development progresses further than that of 129S4 background mice, and results in a centrally-positioned looped heart. This strain may be helpful in studies of cardiac development.

Typically mice are recovered in 12-16 weeks. Contact Customer Service to place an order or for more information.

<a target="_blank" href="https://www.jax.org/jax-mice-and-services/customer-support" rel="noreferrer">Contact Customer Service</a> for more information.