Construction of stable mouse artificial chromosome from native mouse chromosome 10 for generation of transchromosomic mice

Mammalian artificial chromosomes derived from native chromosomes have been applied to biomedical research and development by generating cell sources and transchromosomic (Tc) animals. Human artificial chromosome (HAC) is a precedent chromosomal vector which achieved generation of valuable humanized animal models for fully human antibody production and human pharmacokinetics. While humanized Tc animals created by HAC vector have attained significant contributions, there was a potential issue to be addressed regarding stability in mouse tissues, especially highly proliferating hematopoietic cells. Mouse artificial chromosome (MAC) vectors derived from native mouse chromosome 11 demonstrated improved stability, and they were utilized for humanized Tc mouse production as a standard vector. In mouse, however, stability of MAC vector derived from native mouse chromosome other than mouse chromosome 11 remains to be evaluated. To clarify the potential of mouse centromeres in the additional chromosomes, we constructed a new MAC vector from native mouse chromosome 10 to evaluate the stability in Tc mice. The new MAC vector was transmitted through germline and stably maintained in the mouse tissues without any apparent abnormalities. Through this study, the potential of additional mouse centromere was demonstrated for Tc mouse production, and new MAC is expected to be used for various applications.

Construction of Stable Mouse Artificial Chromosome from Native Mouse Chromosome 10 for Generation of Transchromosomic Mice

Mammalian artificial chromosomes derived from native chromosomes have been applied to biomedical research and development by generating cell sources and transchromosomic (Tc) animals. Human artificial chromosome (HAC) is a precedent chromosomal vector which achieved generation of valuable humanized animal models for fully human antibody production and human pharmacokinetics. While humanized Tc animals created by HAC vector have attained significant contributions, there was a potential issue to be addressed regarding stability in mouse tissues, especially highly proliferating hematopoietic cells. Mouse artificial chromosome (MAC) vectors derived from native mouse chromosome 11 demonstrated improved stability, and they were utilized for humanized Tc mouse production as a standard vector. In mouse, however, stability of MAC vector derived from native mouse chromosome other than mouse chromosome 11 remains to be evaluated. To clarify the potential of mouse centromeres in the additional chromosomes, we constructed a new MAC vector from native mouse chromosome 10 to evaluate the stability in Tc mice. The new MAC vector was transmitted through germline and stably maintained in the mouse tissues without any apparent abnormalities. Through this study, the potential of additional mouse centromere was demonstrated for Tc mouse production, and new MAC is expected to be used for various applications.

Abstract 568: Congenic Mapping of Hypertension in the Nephrectomy Model of Chronic Kidney Disease.

Introduction: We previously reported a locus on mouse chromosome 11 (chrom 11) linked to development of hypertension (HTN) after sub-total nephrectomy (Nx). To begin fine mapping, we used the 129S6 (129) susceptible strain and the C57BL/6 (B6) resistant strain to generate 4 reciprocal congenic lines carrying ~ 2-LOD intervals of the linked locus for recombinant progeny testing. The intervals are defined by microsatellite markers 1-5 and markers 1-6, corresponding to regions defined by markers D11Mit2 and D11Mit177, and D11Mit2 and D11Mit285, respectively. Through brother-sister matings, the 4 lines are as follows: 1) 129 background, homozygous for B6 segment defined by markers 1-5 (129 Chrom11:1-5ofB6 ), 2) 129 background, homozygous for 129 segment defined by markers 1-5 (129 Chrom11:1-5of129 ), 3) B6 background, homozygous for 129 segment defined by markers 1-6 (B6 Chrom11:1-6of129 ) and 4) B6 background, homozygous for B6 segment defined by markers 1-6 (B6 Chrom11:1-6ofB6 ). Methods: Sub-total Nx was performed on male and female congenic mice at ~ 8 weeks of age. Beginning 4 weeks after surgery, using tail cuff manometer, mice were trained for 2 weeks, after which systolic blood pressure (SBP) was recorded daily for 2 weeks. Results: Table 1 summarizes the average SBP of the congenic lines. Conclusion: These findings confirm the effect of this chrom 11 region is dependent on the 129 genetic background, and suggest that interactions between this 129 locus and other loci in the 129 genome are necessary for the development of HTN after nephron mass reduction. Moreover, the influence of this region on chrom 11 appears to be dependent on sex.

Dose Effect and Mode of Inheritance of Diabetogenic Gene on Mouse Chromosome 11

The quantitative trait locus (QTL) mapping in segregating crosses of NSY (Nagoya-Shibata-Yasuda) mice, an animal model of type 2 diabetes, with nondiabetic strain C3H/He mice has identified diabetogenic QTLs on multiple chromosomes. The QTL on chromosome 11 (Chr11) (Nidd1n) showing the largest effect on hyperglycemia was confirmed by our previous studies with homozygous consomic mice, C3H-11NSY, in which the NSY-derived whole Chr11 was introgressed onto control C3H background genes. C3H-11NSYmice also showed a streptozotocin (STZ) sensitivity. In the present study, we constructed heterozygous C3H-11NSYmice and the phenotypes were analyzed in detail in comparison with those of homozygous C3H-11NSYand C3H mice. Heterozygous C3H-11NSYmice had significantly higher blood glucose levels and STZ sensitivity than those in C3H mice. Hyperglycemia and STZ sensitivity in heterozygous C3H-11NSYmice, however, were not as severe as in homozygous C3H-11NSYmice. The body weight and fat pad weight in heterozygous C3H-11NSYmice were similar to those in C3H and homozygous C3H-11NSYmice. These data indicated that the introgression of Chr11 of the diabetes-susceptible NSY strain onto diabetes-resistant C3H caused marked changes in the glucose tolerance and STZ susceptibility even in a heterozygous state, and suggested that the mode of inheritance of a gene or genes on Chr11 for hyperglycemia and STZ sensitivity is additive.