Phenotypes for Thrb MGI:3715602 MGI Mouse

decreased body size ( J:65885 , J:84310 )

• mutants are 17-23% smaller than wild-type at all ages examined (J:65885)

decreased body length ( J:84310 )

• short body length seen postnatally

postnatal growth retardation ( J:65885 , J:84310 )

• mutants exhibit a reduced growth spurt by 25-40% during the age of 3-7 weeks (J:65885)

• the accelerated growth in utero is followed by a slowing of the growth rate in the postnatal period (J:84310)

abnormal fetal growth/weight/body size ( J:84310 )

• mutants exhibit accelerated growth in utero

increased thyrotroph cell number ( J:65885 )

• 2-fold increase in the number of TSH secreting cells in the pituitary

enlarged thyroid gland ( J:65885 )

• thyroid gland is about 18-fold larger than in wild-type

thyroid gland hyperplasia ( J:65885 )

• extensive hyperplasia of the thyroid gland epithelium

abnormal pituitary gland physiology ( J:65885 )

• the extremely high TSH level despite increases in thyroid hormone levels, indicate that the pituitary is resistant to the action of thyroid hormone

abnormal circulating hormone level ( J:65885 )

increased circulating thyroxine level ( J:65885 , J:84310 )

• 15-fold increase in the circulating total T4 concentration (J:65885)

• total T4 levels are elevated 4-, 7-, and 11-fold in neonates, 2 week, and 4 week old homozygotes, respectively; T4 is elevated at time of birth (J:84310)

increased circulating triiodothyronine level ( J:65885 )

• 9-fold increase in the circulating total T3 concentration

increased circulating thyroid-stimulating hormone level ( J:65885 )

• 412-fold higher serum TSH level than in wild-type

abnormal cranium morphology ( J:84310 )

• neonatal skull has an exaggerated curvature of the cranium

short femur ( J:65885 )

• femurs are 12% shorter

short tibia ( J:65885 )

• tibias are 10% shorter

abnormal skeleton development ( J:84310 )

• the length of long bones is increased at E17.5, however at birth, long bone lengths are similar to wild-type and their length is reduced in the early postnatal period, indicating abnormal development of long bones

• increased calcified bone is evident in 2-week old limbs

• mutants exhibit advanced bone formation, leading to growth retardation: by 3 weeks of age, the growth plate is fully organized and the secondary center of ossification that forms the epiphysis of the fibula is present compared to the immature growth plates in wild-type at this time

small fontanelles ( J:84310 )

• fontanelles are smaller at E17.5 and in neonates

abnormal epiphyseal plate morphology ( J:84310 )

• growth plates are narrower at 2 and 3 weeks of age than in wild-type

• at 3 weeks of age, exhibit early quiescence of the growth plates in the upper and lower limbs

abnormal long bone epiphyseal plate proliferative zone ( J:84310 )

• at 2 and 3 weeks of age, the proliferative zone is narrower, however by 4 weeks of age, there is no further narrowing, indicating that the growth plate becomes quiescent between 3 and 4 weeks of age and remains broader instead of continuing to narrow as in wild-type

abnormal long bone hypertrophic chondrocyte zone ( J:84310 )

• at 2 and 3 weeks, the hypertrophic zone is narrower, however by 4 weeks of age, there is no further narrowing, indicating that the growth plate becomes quiescent between 3 and 4 weeks of age and remains broader instead of continuing to narrow as in wild type

abnormal bone mineralization ( J:84310 )

• by 2 weeks of age, trabecular bone mineralization is advanced, with increased mineralization at 4 weeks

premature endochondral bone ossification ( J:84310 )

• neonates exhibit advanced endochondral bone formation at 3 weeks of age

• premature formation of the secondary center of ossification in the fibula

premature intramembranous bone ossification ( J:84310 )

• neonates exhibit advanced bone formation in the skull of the cranial bones and mandible

premature cranial suture closure ( J:84310 )

• craniosynostosis is evident by E17.5 and more pronounced at birth