Mhstq2^{M. macedonius}
QTL Variant Detail

Summary

• QTL variant: Mhstq2^{M. macedonius}
• Name: male hybrid sterility QTL 2; M. macedonius
• MGI ID: MGI:3512501
• QTL: Mhstq2 Location: unknown Genetic Position: ChrX, Syntenic

Variant origin

• Strain of Specimen: M. macedonius

Variant description

• Allele Type: QTL
• Mutation: Undefined
• Mutation details: This allele confers male sterility, decreased testes weight, and absence of sperm in most males compared to C57BL/6J. (J:94029)

Expression

In Structures Affected by this Mutation:

4 anatomical structure(s)

Notes

Mapping and Phenotype information for this QTL, its variants and associated markers

J:94029

Hybrid sterility occurs in F1 males of M. macedonius mated to inbred strains. The testes weight of parental strain C57BL/6J is 0.23 g and the testes weight of parental strain M. macedonius is 0.22 g. The testes weight of F1 males is 0.06 g. Linkage analysis was performed on 140 male animals from a (C57BL/6J x M. macedonius)F1 x C57BL/10J backcross. 92 SSLP markers were used in the genome scan; at least 3 loci were typed for each chromosome. Testes from 8-20 week old backcross animals were weighed and analyzed cytologically.

Linkage to testes weight mapped to proximal mouse Chromosome X near Hprt1 at 17 cM (LOD=7.9). This locus is named Mhstq2. The QTL range of Mhstq2 is broad and spans approximately 1.4 cM - 43.2 cM. This locus accounts for 22% of the phenotypic variation. Mhstq2 was confirmed using congenic animals. (C57BL/6J x M. macedonius)F1 x C57BL/10J females were backcrossed to C57BL/6J for 6 generations while selecting for M. macedonius alleles at DXMit55 (1.4 cM), DXMit23 (17 cM), and DXMit63 (38 cM). The resulting congenic line carries M. macedonius DNA from 1.4 cM - 38 cM on a C57BL/6J background and is designated B.MAC-X(1-38) by the authors. Congenic males are sterile and the average testes weight is 0.052. Cytological analysis of the testes show that most congenic males do not undergo meiotic metaphase I. In most congenic males no sperm heads are present. In rare cases abnormal sperm heads are observed.

The distal end of chromosome X shows linkage to X/Y dissociation of the pseudoautosomal region (PAR). This locus is named Xydsq (X/Y dissociation QTL). Peak linkage to X/Y dissociation occurs at 72 cM near DXMit31 (LOD=4.6). This locus accounts for 42% of the variation of X/Y dissociation.

Linkage to body weight was detected at 34.7 cM near DXMit128 (LOD=4.2) and is named Bywq (body weight QTL). This locus accounts for 12% of the variation in body weight. A previously identified body weight QTL, Bw2 (34 cM), maps near Bywq.

References

• Original: J:94029 Elliott RW, et al., Loci affecting male fertility in hybrids between Mus macedonicus and C57BL/6. Mamm Genome. 2004 Sep;15(9):704-10
• All: 1 reference(s)