Mouse Genome Informatics
hm
    Postntm1Sjc/Postntm1Sjc
involves: C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
mortality/aging
• about 14% of pups die within 2 to 3 weeks of birth

growth/size
• 12 week old mice are about 15 - 30% smaller than wild-type
• 12 week old mice weigh about 50% less than wild-type mice
• placing mice on a soft powdered chow diet decreases the difference in body weight
• growth rate declines around weaning

skeleton
• on average the adult skull is about 7% shorter and 15% narrower than wild-type littermates
• at 4 weeks of age fully erupted molars display widening of the periodontal ligament
• at 3 months of age, high levels of inflammatory infiltrate, primarily consisting of neutrophils, are seen in the periodontal ligament
• presence of this infiltrate results in local conversion of the periodontal ligament to granulation tissue
• foreign particles, such as hair shafts, are seen in the periodontal ligament
• about 16% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• placing mice on a soft powdered chow diet results in bone length similar to wild-type
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• placing mice on a soft powdered chow diet results in bone length similar to wild-type
• about 23% smaller than in wild-type littermates at 4 months of age
• at 4 months of age ribs have smaller growth plates, and contain fewer trabeculae compared to wild-type littermates
• 12% shorter
• 22% narrower in diameter
• trabeculae are reduced in the ribs and limb bones
• placing mice on a soft powdered chow diet grossly rescues the cancellous bone defects
• rib growth plates are smaller

cardiovascular system
• acellular deposits of extracellular matrix produce discontinuities in the valve leaflets and ectopic islands of Acta1 positive cells are found in the leaflets

muscle
N
• myotendinous junctions and the periosteum are similar to wild-type (J:103753)

reproductive system
• smaller, in proportion with overall reduction in body size (J:103753)
• histology appears normal (J:103753)
• smaller, in proportion with overall reduction in body size (J:103753)
• histology appears normal (J:103753)
• smaller, in proportion with overall reduction in body size (J:103753)
• however, histology appears normal and the proliferative phase occurs as normal (J:103753)
• vaginal plugs abnormally persist for up to 3 days (J:103753)
• females fail to cycle; however, folliculogenesis appears intact (J:103753)
• despite plugs and the presence of 2- and 4-cell zygotes no implantation sites are detected at 6 to 10 days after plug detection (J:103753)
• on a powdered soft chow diet some female are able to carry and deliver pups and litter sizes are similar to wild-type but fecundity is reduced to 1.7 +/- 0.5 litters/female compared to 3.1 +/- 0.6 litters/female for wild-type mice on a standard chow diet (J:103753)

immune system
• at 3 months of age, high levels of inflammatory infiltrate, primarily consisting of neutrophils, are seen in the periodontal ligament

endocrine/exocrine glands
N
• histology of the gonads, thyroid glands and pituitaries is normal (J:103753)
• smaller, in proportion with overall reduction in body size (J:103753)
• histology appears normal (J:103753)

limbs/digits/tail
• about 16% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• placing mice on a soft powdered chow diet results in bone length similar to wild-type
• about 11% shorter than in wild-type littermates with fewer trabeculae at 4 months of age
• placing mice on a soft powdered chow diet results in bone length similar to wild-type

craniofacial
• on average the adult skull is about 7% shorter and 15% narrower than wild-type littermates
• at 3 months of age radiographic signs of external root resorption are seen and a significant increase in osteoclast activity is seen in the periodontium
• in adult mice, the enamel epithelium has a psuedostratified structure that appears to produce an amorphous matrix that covers the dentin and is ectopically present within the epithelium
• however, at 2 weeks of age the ameloblast layer appears similar to wild-type
• progressive enamel defect resulting in a decreased mesial-distal area and the presence of a mandibular incisor interproximal space
• at 5 months, the incisal edge is abnormally worn and the enamel surface is deformed and cleft
• incisor canals are obliterated
• placing mice on a soft powdered chow diet reduced the severity of defects
• at 4 weeks of age fully erupted molar roots show signs of resorption
• at 4 weeks of age fully erupted molars display widening of the periodontal ligament
• at 3 months of age, high levels of inflammatory infiltrate, primarily consisting of neutrophils, are seen in the periodontal ligament
• presence of this infiltrate results in local conversion of the periodontal ligament to granulation tissue
• foreign particles, such as hair shafts, are seen in the periodontal ligament
• structural defects are detected by spectroscopy; however, calcium and phosphate content are not significantly different from wild-type
• backscatter scanning electron microscopic images indicate a hypermineralization of the dentin
• progressive incisor enamel defect that result in deformation of the entire facial enamel surface of the upper and lower incisors
• no defect is apparent before weaning
• initially the enamel shows a hypoplastic like condition with decreased translucence and a reduced incisor mesial-distal area
• by 5 months, a highly radiopaque deformed and cleft surface extends from the apex forward to the incisal edge
• also at 5 months the incisor enamel surface is thinner with an irregular and poorly defined structure
• on a powdered soft chow diet only mild clefting of the enamel is seen

Mouse Models of Human Disease
OMIM IDRef(s)
Periodontitis, Aggressive, 2 608526 J:103753