Kinetics of blood glucose in mice carrying hemizygous Pax6.
The genotype-phenotype relationship was examined experimentally for the Pax6(Sey-4H) mutant, which carries deletion of its chromosome 2 middle region hemizygously. The genotyping has indicated that this deleted segment is between 102.6 and 109.2 Mb from the centromere. The glucose-6-phosphatase gene followed by the glucagon and carboxyl ester lipase genes were mapped adjacent to the deleted region. Phenotyping indicates that the Pax6(Sey-4H) mutant is more susceptible to diabetes. The glucose tolerance test showed that the mutants were less capable of reducing their level of blood glucose to the standard level than the normal sibs. The insulin-loading test revealed their inability to elevate their blood glucose levels up to normal levels. The time it took for the onset of diabetes induced by streptozotocin was shorter in the mutants than in normal sibs. Both the haploinsufficiency of the genes in the hemizygous segment of chromosome 2 and the quantitative imbalance of the whole genome could contribute the development of this phenotype in the mutant.
Nitta
Yumiko
Y
Department of Anatomy and Neuroscience, Faculty of Medicine, Kinki University, Osaka-Sayama, Japan.
Shigeyoshi
Yasufumi
Y
Nakagata
Naomi
N
Kaneko
Takehito
T
Nitta
Kohsaku
K
Harada
Toshihide
T
Ishizaki
Fumiko
F
Townsend
Jana
J
D000818:Animals; D001786:Blood Glucose / Q000235:genetics*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000209:etiology; D005136:Eye Proteins / Q000235:genetics*; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D005951:Glucose Tolerance Test; D006579:Heterozygote; D018398:Homeodomain Proteins / Q000235:genetics*; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology; D007700:Kinetics; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*
D001786:Blood Glucose; D005136:Eye Proteins; D018398:Homeodomain Proteins; D007328:Insulin; D008112:Liver Glycogen; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins