A deletion causing spontaneous fracture identified from a candidate region of mouse Chromosome 14.
Map-based cloning is an iterative approach that identifies the underlying genetic cause of a mutant phenotype. However, the classic protocol of positional cloning is time-consuming and labor-intensive. We now describe a genome sequence-based cloning approach that has led to localizing the underlying genetic cause of spontaneous fractures (sfx) in a mouse model. The sfx/sfx mouse is characterized by a spontaneous femoral fracture seen around 6 weeks of age, which represents a new mouse model for bone fragility. Genetic studies indicate that the phenotype of sfx/sfx mice is caused by an alteration at a single locus that is roughly mapped onto the central region of mouse Chromosome 14. Using our strategy of combining mouse genome resources and high-throughput technology, we discovered a deletion of all 12 exons in the gene for L-gulonolactone oxidase (LGO), a key enzyme in the synthesis of ascorbic acid. We have also examined the expression of LGO and found no expression of LGO in sfx mice while the LGO expresses in several tissues of normal mice. Our data demonstrated the feasibility to positionally clone the mutated gene from a non-fine-mapped locus, which has applicability to the positional cloning of genes from many other animal models, as their genome sequences are sequenced or will be sequenced soon.
Jiao
Yan
Y
Department of Orthopedic Surgery-Campbell Clinic, Center of Genomics and Bioinformatics & Center of Diseases of Connective Tissues, University of Tennessee Health Science Center, Memphis, Tennessee, 38163, USA.
Li
Xinmin
X
Beamer
Wesley G
WG
Yan
Jian
J
Tong
Yiai
Y
Goldowitz
Daniel
D
Roe
Bruce
B
Gu
Weikuan
W
D000818:Animals; D002874:Chromosome Mapping; D005260:Female; D005264:Femoral Fractures / Q000235:genetics; D005598:Fractures, Spontaneous / Q000235:genetics*; D017353:Gene Deletion; D017403:In Situ Hybridization; D050544:L-Gulonolactone Oxidase; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000201:enzymology; D008297:Male; D051379:Mice; D009206:Myocardium / Q000201:enzymology; D020641:Polymorphism, Single Nucleotide; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013131:Spine / Q000201:enzymology; D013401:Sugar Alcohol Dehydrogenases / Q000235:genetics*
D013401:Sugar Alcohol Dehydrogenases; D050544:L-Gulonolactone Oxidase