Phenotypes for Dsg4 MGI:2661068 MGI Mouse

postnatal lethality, incomplete penetrance ( J:83117 )

• severely affected homozygotes become weak and die before weaning

decreased birth body size ( J:83117 )

• at birth, homozygotes are slightly smaller than heterozygous control mice

decreased body size ( J:83117 )

• homozygotes remain runted throughout life

decreased body weight ( J:83117 )

• homozygotes exhibit reduced body weights throughout their lifespan

abnormal skin pigmentation ( J:83117 )

• at 4-8 weeks of age, the skin is slightly darker in color

increased IgE level ( J:83117 )

• homozygotes display significantly elevated IgE levels relative to control mice

• interestingly, IgE levels in male homozygotes are ~50% of those found in female homozygotes, indicating a sexually dichotomy

abnormal peripheral lymph node morphology ( J:83117 )

• homozygotes display enlarged peripheral lymph nodes

dermatitis ( J:83117 )

• affected homozygotes display ichthyosiform dermatitis

decreased subcutaneous adipose tissue amount ( J:83117 )

• homozygotes exhibit significantly reduced fat reserves in the subcutis

decreased abdominal adipose tissue amount ( J:83117 )

• homozygotes exhibit significantly reduced fat reserves in the peritoneal cavity

abnormal sebaceous gland morphology ( J:83117 )

• sebaceous glands associated with truncal hair follicles are hard to identify in anagen follicles in the second hair cycle

decreased subcutaneous adipose tissue amount ( J:83117 )

• homozygotes exhibit significantly reduced fat reserves in the subcutis

abnormal sebaceous gland morphology ( J:83117 )

• sebaceous glands associated with truncal hair follicles are hard to identify in anagen follicles in the second hair cycle

dermatitis ( J:83117 )

• affected homozygotes display ichthyosiform dermatitis

abnormal hair growth ( J:83117 )

alopecia ( J:83117 )

• aging homozygotes become alopecic and lose the "peach fuzz" appearance

• however, hair is still present on the head and shoulders

short hair ( J:83117 )

• at 4-8 weeks of age, hair is shorter than normal and close to the body, resulting in a "peach fuzz" appearance

sparse hair ( J:83117 )

• at 4-8 weeks of age, truncal hair is sparse

abnormal hair texture ( J:83117 )

• mutant hairs display prominent swellings, usually at break sites, with loss of septate and septulate patterns of the hair shaft

• some fibers appear to invaginate along the length of the shaft (trichorrhexis invaginata); however, this is a hair cycle dependent feature

• a couple of homozygotes display hairs with spiral folds (pili torti) and tapered fractures, corkscrew hair with torsion nodule, lanceolate hair, and nodular swelling

deformed nails ( J:83117 )

• as homozygotes age, nails on the hind feet become curled and misshapen, resembling onychogryposis

• some nails or toes undergo autoamputation such that only stubs are visible at necropsy

long toenails ( J:83117 )

• as homozygotes age, nails on the hind feet appear overgrown

• in contrast, nails on the fore feet remain normal

abnormal hair follicle morphology ( J:83117 )

• starting at P9, all pelage hair follicles appear abnormal

• late anagen follicles initially show a focal change just above the hair bulb in the matrix region along with focal swellings of hair fibers; this "onion-skin-like" area is pushed up and out of the follicle by a relatively normal hair fiber that forms below it

• as follicles proceed into catagen, they show progressive changes leading to follicular and fiber dystrophy with severe fiber distortion, including twisting, breakage, and rupture through the follicle wall, associated with various degrees of inflammation composed of foreign body granulomas

• progression into telogen is associated with resolution of the inflammation with various degress of scarring and granulation tissue right below the epidermis

absent vibrissae ( J:83117 )

• as early as P1, homozygotes are readily recognizable by the absence of vibrissae

mixed cellular infiltration to dermis ( J:83117 )

• starting at P9, the dermis shows a moderate increase in mixed inflammatory cells, mainly neutrophils

thick dermal layer ( J:83117 )

• the dermis increases in thickness, corresponding to entry into catagen with associated follicular rupture, foreign body granuloma formation, hyperplasia of follicular root sheaths and, finally, diffuse scarring

hyperkeratosis ( J:83117 )

• the stratum corneum fails to decrease in thickness within the first 2 weeks of life, resulting in an ichthyosiform phenotype

parakeratosis ( J:83117 )

• starting at P9, the stratum corneum displays a prominent scale with focal parakeratosis

acanthosis ( J:83117 )

• starting at P9, the epidermis displays moderate acanthosis and orthokeratosis

thick epidermis ( J:83117 )

• starting at P9

scaly skin ( J:83117 )

• by P9, homozygotes display fine scaling of the skin

• scaling persists throughout the first 2 months of life

wrinkled skin ( J:83117 )

• at 4-8 weeks of age, homozygotes display a much thicker and wrinkled skin

abnormal skin pigmentation ( J:83117 )

• at 4-8 weeks of age, the skin is slightly darker in color

abnormal skin condition ( J:83117 )

• affected homozygotes develop a non-inflammatory, proliferative skin disease with follicular dystrophy

thick skin ( J:83117 )

• by P9, homozygotes display thick folded skin

• thickness persists throughout the first 2 months of life and decreases thereafter

decreased skin tensile strength ( J:83117 )

• at 4-8 weeks of age, the skin is more fragile than normal