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QTL on mouse chromosomes 1 and 4 causing sperm-head morphological abnormality and male subfertility.

Gotoh H, Hirawatari K, Hanzawa N, Miura I, Wakana S - Mamm. Genome (2012)

Bottom Line: It was also found that the effects of these two loci were not independent.The major locus on Chr 1 determines the expression of sperm-head abnormalities, while the locus on Chr 4 enhances the frequency of abnormalities only when the genotype of the Chr 1 locus is homozygous for the B10.M allele.The major locus on Chr 1 was named sperm-head morphology 1 (Shm1), while the modifier locus on Chr 4 was named sperm-head morphology 2 (Shm2).

View Article: PubMed Central - PubMed

Affiliation: Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. gotoh@affrc.go.jp

ABSTRACT
The B10.M mouse strain represents a model for male subfertility as it produces a significantly low number of offspring. The only known male reproductive phenotype of this strain is its high frequency of sperm-head morphological abnormalities (44.7 ± 2.4 %). We previously reported that this phenotype was the product of two recessive loci. In this study we mapped the loci causing the high frequency of sperm-head morphological abnormalities in this strain using F2 animals produced by crossing B10.M and C3H mice. Quantitative trait loci (QTL) analysis (n = 178) identified two recessive genes, one on Chromosome (Chr) 1 (LOD score = 30.585) and one on Chr 4 (LOD score = 4.532). Further analysis (n = 854) mapped the locus on Chr 1 between Ercc5 (23.55 cM) and D1Mit528 (25.95 cM) and the locus on Chr 4 between D4Mit148 (69.48 cM) and D4Mit170 (70.47 cM). It was also found that the effects of these two loci were not independent. The major locus on Chr 1 determines the expression of sperm-head abnormalities, while the locus on Chr 4 enhances the frequency of abnormalities only when the genotype of the Chr 1 locus is homozygous for the B10.M allele. The major locus on Chr 1 was named sperm-head morphology 1 (Shm1), while the modifier locus on Chr 4 was named sperm-head morphology 2 (Shm2).

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Effects of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4 on sperm-head abnormalities. The frequency of sperm-head abnormalities was plotted for each genotype concerning the responsible loci on Chrs 1 and 4. The genotypes of D1Mit236 and D4Mit158 were used for the genotypes of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4, respectively. The alleles from B10.M and C3H were denoted as “m” and “+,” respectively. Each square stands for the value of an individual. The squares with arrows indicate that the high frequency of sperm-head abnormalities (>20 %) of these animals was independent of the effects of the B10.M alleles for both of the responsible loci. The bar in each genotype represents the mean frequency of sperm-head abnormalities
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Fig2: Effects of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4 on sperm-head abnormalities. The frequency of sperm-head abnormalities was plotted for each genotype concerning the responsible loci on Chrs 1 and 4. The genotypes of D1Mit236 and D4Mit158 were used for the genotypes of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4, respectively. The alleles from B10.M and C3H were denoted as “m” and “+,” respectively. Each square stands for the value of an individual. The squares with arrows indicate that the high frequency of sperm-head abnormalities (>20 %) of these animals was independent of the effects of the B10.M alleles for both of the responsible loci. The bar in each genotype represents the mean frequency of sperm-head abnormalities

Mentions: The frequency of sperm-head abnormalities (n = 456) was plotted for each Shm1 and Shm2 genotype (Fig. 2). A significant difference was observed between B10.M Shm1 homozygous mice and mice with other genotypes (P < 0.05). A significant difference was also observed within the B10.M Shm1 homozygotes and between B10.M Shm2 homozygotes and animals with other genotypes (P < 0.05). No significant difference was observed between C3H Shm2 homozygotes and Shm2 heterozygotes carrying B10.M Shm1 homozygously. Among the other genotype groups, including C3H Shm1 homozygotes and heterozygotes, no significant difference was observed between any genotype combinations.Fig. 2


QTL on mouse chromosomes 1 and 4 causing sperm-head morphological abnormality and male subfertility.

Gotoh H, Hirawatari K, Hanzawa N, Miura I, Wakana S - Mamm. Genome (2012)

Effects of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4 on sperm-head abnormalities. The frequency of sperm-head abnormalities was plotted for each genotype concerning the responsible loci on Chrs 1 and 4. The genotypes of D1Mit236 and D4Mit158 were used for the genotypes of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4, respectively. The alleles from B10.M and C3H were denoted as “m” and “+,” respectively. Each square stands for the value of an individual. The squares with arrows indicate that the high frequency of sperm-head abnormalities (>20 %) of these animals was independent of the effects of the B10.M alleles for both of the responsible loci. The bar in each genotype represents the mean frequency of sperm-head abnormalities
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3401295&req=5

Fig2: Effects of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4 on sperm-head abnormalities. The frequency of sperm-head abnormalities was plotted for each genotype concerning the responsible loci on Chrs 1 and 4. The genotypes of D1Mit236 and D4Mit158 were used for the genotypes of the Shm1 locus on Chr 1 and the Shm2 locus on Chr 4, respectively. The alleles from B10.M and C3H were denoted as “m” and “+,” respectively. Each square stands for the value of an individual. The squares with arrows indicate that the high frequency of sperm-head abnormalities (>20 %) of these animals was independent of the effects of the B10.M alleles for both of the responsible loci. The bar in each genotype represents the mean frequency of sperm-head abnormalities
Mentions: The frequency of sperm-head abnormalities (n = 456) was plotted for each Shm1 and Shm2 genotype (Fig. 2). A significant difference was observed between B10.M Shm1 homozygous mice and mice with other genotypes (P < 0.05). A significant difference was also observed within the B10.M Shm1 homozygotes and between B10.M Shm2 homozygotes and animals with other genotypes (P < 0.05). No significant difference was observed between C3H Shm2 homozygotes and Shm2 heterozygotes carrying B10.M Shm1 homozygously. Among the other genotype groups, including C3H Shm1 homozygotes and heterozygotes, no significant difference was observed between any genotype combinations.Fig. 2

Bottom Line: It was also found that the effects of these two loci were not independent.The major locus on Chr 1 determines the expression of sperm-head abnormalities, while the locus on Chr 4 enhances the frequency of abnormalities only when the genotype of the Chr 1 locus is homozygous for the B10.M allele.The major locus on Chr 1 was named sperm-head morphology 1 (Shm1), while the modifier locus on Chr 4 was named sperm-head morphology 2 (Shm2).

View Article: PubMed Central - PubMed

Affiliation: Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. gotoh@affrc.go.jp

ABSTRACT
The B10.M mouse strain represents a model for male subfertility as it produces a significantly low number of offspring. The only known male reproductive phenotype of this strain is its high frequency of sperm-head morphological abnormalities (44.7 ± 2.4 %). We previously reported that this phenotype was the product of two recessive loci. In this study we mapped the loci causing the high frequency of sperm-head morphological abnormalities in this strain using F2 animals produced by crossing B10.M and C3H mice. Quantitative trait loci (QTL) analysis (n = 178) identified two recessive genes, one on Chromosome (Chr) 1 (LOD score = 30.585) and one on Chr 4 (LOD score = 4.532). Further analysis (n = 854) mapped the locus on Chr 1 between Ercc5 (23.55 cM) and D1Mit528 (25.95 cM) and the locus on Chr 4 between D4Mit148 (69.48 cM) and D4Mit170 (70.47 cM). It was also found that the effects of these two loci were not independent. The major locus on Chr 1 determines the expression of sperm-head abnormalities, while the locus on Chr 4 enhances the frequency of abnormalities only when the genotype of the Chr 1 locus is homozygous for the B10.M allele. The major locus on Chr 1 was named sperm-head morphology 1 (Shm1), while the modifier locus on Chr 4 was named sperm-head morphology 2 (Shm2).

Show MeSH
Related in: MedlinePlus