XYAKR-Sxr mice are normal males at wean age. Furthermore, while embryonic assessment of C57BL/6JEi-Chr YAKR consomic mice reveals delayed testes cord differentiation, embryonic assessment of C57BL/6JEi-Chr YAKR-Sxr shows normal cord differentiation in the testes.
Tp(Y)1CtSxr-a is a duplication including most of the short arm of the Y Chromosome along with Sry from the distal end of the long arm. This Sxr-bearing segment was transferred initially from the Y Chromosome to an X Chromosome so that it could subsequently be transferred to the Y Chromosome of AKR/J. Because XXSxr mice are sterile the intermediate host X Chromosome had the T(16;X) translocation, which caused preferential X inactivation of the XSxr thereby permitting transmission. The XXSxr fertile females were bred with C57BL/6JEi-Chr YAKR/Ei males yielding XSxr/YAKR/J males. During meiosis in some of these males the Sxr-bearing segment was transferred to the YAKR/J Chromosome in some gametes. The resulting male offspring identified as having the Tp(Y)1Ct-derived Sxr-bearing segment on the YAKR/J Chromosome were backcrossed to C57BL/6JEi to generate this strain. In 1999 embryos were generated for cryopreservation from C57BL/6JEi females and carrier males at backcross generation N11.
Currently there are no related genes or alleles for this strain.