Naq2^C57BL/6J
QTL Variant Detail

Summary

• QTL variant: Naq2^C57BL/6J
• Name: nurturing ability QTL 2; C57BL/6J
• MGI ID: MGI:5904939
• QTL: Naq2 Location: unknown Genetic Position: Chr4, Syntenic

Variant origin

• Strain of Specimen: C57BL/6J

Variant description

• Allele Type: QTL

Notes

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

J:237758

In the current study, the hypotheses that the low survival rate of newborn offspring of the inbred strain RR/SgnRbrc (RR) is a consequence of the inferior nurturing ability of RR mothers and that the mothers have a tendency to lose their pups was examined.

To compare nurturing ability and tendency to lose pups between RR and C57BL/6J (B6) mothers, reciprocal crosses were performed. Nurturing ability was evaluated by litter weight, and tendency to lose pups was evaluated by scoring whether or not the mothers

lost their F1 pups. For QTL analysis, B6 females were crossed with RR males to produce B6 RR F1 mice. F1 females were then crossed with RR males to produce (B6 RR) RR backcross (hereafter BC) progeny.

Nurturing ability was evaluated by litter weight, and tendency to lose pups was evaluated by scoring whether or not the mothers lost their pups. QTL analysis was conducted using R/qtl. Threshold logarithm of odds (LOD) scores for suggestive (P<0.63) and significant (P<0.05) linkages was determined by performing 1,000 permutations for each trait. For significant QTL, a 95% confidence interval (CI) was defined by a decline of 1.5 LOD. After single QTL scans, pairwise evaluations for potential interactions between loci were performed. 165 F2 mice were genotyped with 92 microsatellite markers.

One significant QTL on chromosome 4 and 3 suggestive QTLs on chromosomes 7, 9 and 17 were identified (Table 2 and Fig. 1B). At all loci, the RR allele was associated with lower litter weight (Fig. 1C). The significant QTL on chromosome 4 was named Naq2 (nurturing ability QTL 2). Naq2 mapped to Chr 4 with a LOD score of 4.27 at 51 cM nearest marker D4Mit306.

On the basis of the analysis of tendency to lose pups, suggestive QTL were identified on chromosomes 4, 9 and 16. It was important to note that the RR allele was associated with an increased tendency to lose pups at all QTLs. Of the QTL, those on chromosomes 4 and 9 may be allelic with those identified in the analysis of inferior nurturing ability

according to their chromosomal locations. Therefore, Naq2 on chromosome 4 had significant and suggestive effects on litter weight and tendency of losing pups, respectively.

References

• Original: J:237758 Suto J, Genetic analysis of low survival rate of pups in RR/Sgn inbred mice. J Vet Med Sci. 2015 Jul;77(7):809-13
• All: 1 reference(s)