adipose tissue phenotype

• decreased total body fat amount
  • at autopsy, homozygotes exhibit a dramatic reduction in body fat, reminiscent of a starvation phenotype
  (MGI Ref ID J:40804)

growth/size/body region phenotype

• postnatal growth retardation
  • starting at P8-P10, homozygotes exhibit progressive growth retardation
  (MGI Ref ID J:40804)

• mouth mucosal ulcer
  • suckling and, later, solid food at P16-P20 presumably exacerbate the severity of oral lesions
  (MGI Ref ID J:40804)
  • oropharyngeal biopsies indicate suprabasilar acantholysis and "tombstoning" of basal cells while EM reveals separation of desmosomes
  (MGI Ref ID J:40804)
  • homozygotes exhibit oral mucous membrane inflammatory erosions and suprabasal blisters that may inhibit food intake and ultimately cause runting
  (MGI Ref ID J:40804)

• decreased body size
  • at P15-P20, homozygotes are grossly runted
  (MGI Ref ID J:40804)

• weight loss
  • weight loss is noted at ~P20, i.e. at around weaning and start of solid food
  (MGI Ref ID J:40804)

• decreased body weight
  • homozygotes are born with normal weight but are lagging in weight gain by P8-P10
  (MGI Ref ID J:40804)

immune system phenotype

• conjunctivitis
  • some homozygotes display suppurative conjunctivitis with suprabasilar blisters of eyelids and mucocutaneous conjunctiva
  (MGI Ref ID J:40804)

cellular phenotype

• abnormal cell adhesion
  • homozygotes display impaired cell adhesion in the basal and immediate suprabasilar keratinocytes, esp. in the oral mucous membrane
  (MGI Ref ID J:40804)

integument phenotype

• skin lesions
  • nursing mothers display nipple erosions caused by suckling
  (MGI Ref ID J:40804)
  • homozygotes do not show any tail abnormalities or flaky skin but develop crusted erosions around the eyes and snout, areas that are normally traumatized by scratching
  (MGI Ref ID J:40804)

• abnormal hair cycle
  • homozygotes exhibit a normal first hair cycle but loss of hair after this cycle
  (MGI Ref ID J:40804)
  • head to tail synchronization is lost after 2-3 cycles
  (MGI Ref ID J:40804)
  • as a result, bald patches with regrowth, involving both the ventral and dorsal coats, are observed
  (MGI Ref ID J:40804)

• alopecia
  • bald areas are first noted on the forehead, and then proceed onto the entire back
  (MGI Ref ID J:40804)
  • runted homozygotes display alopecia at weaning
  (MGI Ref ID J:40804)

• blistering
  • traumatized skin around the eyes and snout shows typical suprabasilar blisters similar to pemphigus vulgaris lesions
  (MGI Ref ID J:40804)
  • homozygotes may display suprabasilar blistering of the vaginal epithelium; however, the esophagus, cardiac portion of the stomach, and thymus appear histologically normal
  (MGI Ref ID J:40804)

• abnormal hair shaft morphology
  • balding homozygotes display dilated telogen follicles lacking a hair shaft
  (MGI Ref ID J:40804)

• acantholysis
  • oropharyngeal biopsies indicate suprabasilar acantholysis and "tombstoning" of basal cells
  (MGI Ref ID J:40804)
  • separated acantholytic cells retain "half" desmosomes with tonofilaments still attached and residual flocculent material (desmoglea) along the cell membrane
  (MGI Ref ID J:40804)

mortality/aging

• lethality at weaning, incomplete penetrance
  • a few homozygotes die between P18 and P25, following severe weight loss
  (MGI Ref ID J:40804)
  • however, more than 80% survive and again start to gain weight, although they remain clearly smaller than wild-type littermates
  (MGI Ref ID J:40804)

craniofacial phenotype

• mouth mucosal ulcer
  • homozygotes exhibit oral mucous membrane inflammatory erosions and suprabasal blisters that may inhibit food intake and ultimately cause runting
  (MGI Ref ID J:40804)
  • oropharyngeal biopsies indicate suprabasilar acantholysis and "tombstoning" of basal cells while EM reveals separation of desmosomes
  (MGI Ref ID J:40804)
  • suckling and, later, solid food at P16-P20 presumably exacerbate the severity of oral lesions
  (MGI Ref ID J:40804)

vision/eye phenotype

• conjunctivitis
  • some homozygotes display suppurative conjunctivitis with suprabasilar blisters of eyelids and mucocutaneous conjunctiva
  (MGI Ref ID J:40804)

digestive/alimentary phenotype

• mouth mucosal ulcer
  • oropharyngeal biopsies indicate suprabasilar acantholysis and "tombstoning" of basal cells while EM reveals separation of desmosomes
  (MGI Ref ID J:40804)
  • homozygotes exhibit oral mucous membrane inflammatory erosions and suprabasal blisters that may inhibit food intake and ultimately cause runting
  (MGI Ref ID J:40804)
  • suckling and, later, solid food at P16-P20 presumably exacerbate the severity of oral lesions
  (MGI Ref ID J:40804)