Phenotypes associated with this allele

• Allele Symbol: Ghrhr^lit
• Allele Name: little
• Allele ID: MGI:1856425
• Summary: 6 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ghrhr^lit/Ghrhr^lit	C3.B6-Ghrhr^lit/J	MGI:5568696
hm2	Ghrhr^lit/Ghrhr^lit	C57BL/6J-Ghrhr^lit	MGI:2677718
hm3	Ghrhr^lit/Ghrhr^lit	C57BL/6J-Ghrhr^lit/J	MGI:4360659
cx4	Ghrhr^lit/Ghrhr^lit M14104Asr/M14104Asr^+	C57BL/6J-Ghrhr^lit M14104Asr	MGI:3823056
cx5	Ghrhr^lit/Ghrhr^+ M14104Asr/M14104Asr^+	C57BL/6J-Ghrhr^lit M14104Asr	MGI:3823055
cx6	Ghrhr^lit/Ghrhr^lit Prlr^tm1Cnp/Prlr^tm1Cnp	involves: 129P2/OlaHsd * C57BL/6J	MGI:4431047

Genotype
MGI:5568696

hm1

• Allelic Composition: Ghrhr^lit/Ghrhr^lit
• Genetic Background: C3.B6-Ghrhr^lit/J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

skeleton

short femur ( J:209717 )

• at 4 months of age the average femur length in homozygous females on the C3H/HeJ background is 12.3mm versus 15.2mm in heterozygotes

• at 4 months of age the average femur length in homozygous males on the C3H/HeJ background is 12.4mm versus 15.7mm in heterozygotes

abnormal bone structure ( J:209717 )

• The average periosteal circumference in homozygous females (3.43 mm) is significantly less than in heterozygotes (4.36 mm) and similar results are found on the C57BL/6J background so there is not a strong impact of genetic background on body size and bone geometry as there is on bone mineral density

• The average periosteal circumference in homozygous males (3.85 mm) is significantly less than in heterozygotes (4.88 mm) and similar results are found on the C57BL/6J background so there is not a strong impact of genetic background on body size and bone geometry as there is on bone mineral density

abnormal bone mineral density ( J:209717 )

• Background Sensitivity: on a C3H/HeJ congenic background homozygous females at 4 months of age have a femoral bone mineral density of 0.582 mg/mm³ compared with 0.451 mg/mm³ on the C57BL/6J background

• Background Sensitivity: on a C3H/HeJ congenic background homozygous males at 4 months of age have a femoral bone mineral density of 0.61 mg/mm³ compared with 0.453 mg/mm³ on the C57BL/6J background

• Background Sensitivity: the whole body bone mineral density measured between 4 and 16 weeks of age is significantly lower in homozygotes on the C57BL/6J background than on the C3H/HeJ background and is lower in homozygotes than heterozygotes

decreased bone mineral density of femur ( J:209717 )

decreased volumetric bone mineral density ( J:209717 )

• at 4 months of age homozygous females have a femoral bone mineral density of 0.582 mg/mm³ where heterozygote have 0.698 mg/mm³

• at 4 months of age homozygous males have a femoral bone mineral density of 0.61 mg/mm³ where heterozygote have 0.691 mg/mm³

growth/size/body

decreased body weight ( J:209717 )

• homozygous females at 4 months of age weigh on average 15.8g whereas heterozygotes weigh 27.5g

• homozygous males at 4 months of age weigh on average 25.8g whereas heterozygotes weigh 35.8g

limbs/digits/tail

short femur ( J:209717 )

• at 4 months of age the average femur length in homozygous females on the C3H/HeJ background is 12.3mm versus 15.2mm in heterozygotes

• at 4 months of age the average femur length in homozygous males on the C3H/HeJ background is 12.4mm versus 15.7mm in heterozygotes

homeostasis/metabolism

abnormal insulin-like growth factor I level ( J:209717 )

• average IGF-1 levels in homozygous males (46.5 ng/ml) is much lower than in heterozygous males (208.8 ng/ml) but simlar to homozygous females on a C57BL/6J background (37.0 ng/ml)

• average IGF-1 levels in homozygous males (34.2 ng/ml) is much lower than in heterozygous males (186.3 ng/ml) but simlar to homozygous males on a C57BL/6J background (31.2 ng/ml)

Genotype
MGI:2677718

hm2

• Allelic Composition: Ghrhr^lit/Ghrhr^lit
• Genetic Background: C57BL/6J-Ghrhr^lit

adipose tissue

increased total body fat amount ( J:3735 )

• greater amounts than wild-type controls

endocrine/exocrine glands

abnormal somatotroph morphology ( J:7211 )

decreased somatotroph cell number ( J:7211 )

decreased somatotroph cell size ( J:7211 )

decreased somatotroph secretory granule number ( J:7211 )

• some cells are devoid of secretory granules

absent somatotroph secretory granules ( J:7211 )

• some cells have reduced numbers of secretory granules

small pituitary gland ( J:5647 )

abnormal lactation ( J:5647 )

♀ • failed milk production with first, but not subsequent, litters

growth/size/body

obese ( J:81023 )

• at 40 weeks of age the body fat of homozygous males is considerably higher than that of heterozygous males

increased susceptibility to age related obesity ( J:5647 )

proportional dwarf ( J:5710 )

• proportionate skeletal size reduction

abnormal postnatal growth ( J:5710 , J:81023 )

• female homozygotes mated to intact or vasectomized males gain weight as a result of pregnancy or pseudopregnancy and have increased bone length in the tibia and femur, and increased length and width in the scapula and skull (J:5710)

• both males and females have increased weight and bone growth as a result of pituitary grafts or a course of i.p. injections of ovine growth hormone (J:5710)

• homozygous males display a linear increase of weight from 4 to 16 weeks of age; they do not have a peak growth rate at 5 weeks of age, which heterozygous males do, and out to 16 weeks of age homozygotes do not show a plateau in their body weight, which heterozygotes do by approximately 12 to 15 weeks of age (J:81023)

postnatal growth retardation ( J:5647 )

• reduced weight, beginning at 2 weeks of age

homeostasis/metabolism

decreased growth hormone level ( J:5647 )

• in the pituitary

decreased circulating growth hormone level ( J:3735 )

decreased prolactin level ( J:5647 )

• in the pituitary

abnormal metabolism ( J:81023 )

• from 4 to 15 weeks of age homozygous males exhibit constant food conversion efficiency rather than the normal decay of food conversion efficiency seen in heterozygous controls

• homozygous males have a higher energy consumption per gram of body weight than do heterozygous controls

reproductive system

reduced male fertility ( J:5647 )

♂ • only 50% sired first litters, only 50% of these sired second litters, third litters rare

nervous system

abnormal somatotroph morphology ( J:7211 )

decreased somatotroph cell number ( J:7211 )

decreased somatotroph cell size ( J:7211 )

decreased somatotroph secretory granule number ( J:7211 )

• some cells are devoid of secretory granules

absent somatotroph secretory granules ( J:7211 )

• some cells have reduced numbers of secretory granules

small pituitary gland ( J:5647 )

behavior/neurological

behavior/neurological phenotype ( J:81023 )

N • although mature food intake is less than that of heterozygotes, it is commensurate with body weight with heterozygous males taking in an average 1.0 +/- .12 g/g body weight and homozygous males taking in an average of 1.2 +/- .23 g/g body weight

abnormal sleep pattern ( J:82887 )

• homozygotes have shorter non-rapid eye movement sleep episodes during the light period and have them slightly more frequently than do heterozygotes, homozygotes also have significantly decreased rapid eye movement sleep episode frequency during the light period although the duration of rapid eye movement sleep episodes is normal

• subcutaneous infusion of growth hormone increases the frequency of rapid eye movement sleep episodes during the light cycle to levels similar to those of heterozygous controls, although infusion of growth hormone does not correct the non-rapid eye movement sleep episodes

abnormal frequency of paradoxical sleep ( J:82887 )

skeleton

decreased bone mass ( J:81023 )

• homozygous males have a lower bone mass than heterozygous males although the bone mass of both attains maturity at 12 to 15 weeks of age and has a maximum growth rate at 5 weeks

abnormal skeleton development ( J:5710 )

• female homozygotes mated to intact or vasectomized males gain weight as a result of pregnancy or pseudopregnancy and have increased bone length in the tibia and femur, and increased length and width in the scapula and skull

• both males and females have increased weight and bone growth as a result of pituitary grafts or a course of i.p. injections of ovine growth hormone

integument

abnormal lactation ( J:5647 )

♀ • failed milk production with first, but not subsequent, litters

immune system

decreased susceptibility to experimental autoimmune encephalomyelitis ( J:85381 )

Genotype
MGI:4360659

hm3

• Allelic Composition: Ghrhr^lit/Ghrhr^lit
• Genetic Background: C57BL/6J-Ghrhr^lit/J

Ghrhr^lit/Ghrhr^lit and Ghrhr^lit/Ghrhr⁺ mice

homeostasis/metabolism

abnormal glucose homeostasis ( J:95779 )

• at P7, the ratio of glucose to insulin is increased compared to in wild-type mice or either single homozygote

decreased circulating glucose level ( J:95779 )

• at 3 and 12 months, mice exhibit decreased serum glucose level compared with wild-type mice

increased circulating insulin level ( J:95779 )

• at P7 and in adult mice

abnormal insulin-like growth factor I level ( J:209717 )

• average IGF-1 levels in homozygous females (37 ng/ml) is much lower than in heterozygous females (171 ng/ml) and in homozygous males (31.2 ng/ml) is much lower than in heterozygous males (171.4 ng/ml)

decreased circulating insulin-like growth factor I level ( J:95779 )

• at P7

growth/size/body

decreased lean body mass ( J:95779 )

• relative to body weight in male mice

decreased body weight ( J:95779 , J:209717 )

• through 500 days, female mice exhibit decreased body weight compared with wild-type mice (J:95779)

• at 4 months of age homozygous females weigh an average of 16.5g compared with heterozygous females 21.9g, and homozygous males weigh an average of 20.1g compared with heterozgyous males 30.2g (J:209717)

slow postnatal weight gain ( J:95779 )

• male and female mice exhibit reduced body weight gain compared with wild-type mice

• however, male mice exhibit catch-up weight-gain at 120 to 180 days of life

skeleton

short femur ( J:95779 , J:209717 )

• at 4 months of age the average femur length in homozygous females on the C57BL/6J background is 12mm versus 15.4mm in heterozygotes, and in homozygous males is 12mm versus 15.6mm in heterozygotes (J:209717)

abnormal bone structure ( J:209717 )

• At 4 months of age, the average periosteal circumference in homozygous females (3.8 mm) is significantly less than in heterozygotes (4.76 mm), and in homozygous males (3.66 mm) is also significantly less than in heterozygotes (4.9 mm)

decreased bone mineral density ( J:209717 )

• Background Sensitivity: whole body bone mineral density measured between 4 and 16 weeks of age is significantly lower in homozygotes on the C57BL/6J background than on the C3H/HeJ background and is lower in homozygotes than heterozygotes

decreased bone mineral density of femur ( J:209717 )

• at 4 months of age, homozygous females have a femoral bone mineral density of 0.451 mg/mm³ whereas heterozygotes have 0.482 mg/mm³

• at 4 months of age, homozygous males have a femoral bone mineral density of 0.453 mg/mm³ whereas heterozygotes have 0.502 mg/mm³

increased bone mineral density ( J:95779 )

adipose tissue

increased total body fat amount ( J:95779 )

• body fat relative to femur length in male mice is increased compared to in wild-type mice

limbs/digits/tail

short femur ( J:95779 , J:209717 )

• at 4 months of age the average femur length in homozygous females on the C57BL/6J background is 12mm versus 15.4mm in heterozygotes, and in homozygous males is 12mm versus 15.6mm in heterozygotes (J:209717)

Genotype
MGI:3823056

cx4

• Allelic Composition: Ghrhr^lit/Ghrhr^lit; M14104Asr/M14104Asr⁺
• Genetic Background: C57BL/6J-Ghrhr^lit M14104Asr

growth/size/body

decreased body weight ( J:141536 )

skeleton

decreased diameter of femur ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the femur are reduced; however, the cortical thickness and the length is similar to control

decreased diameter of tibia ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the tibia are reduced; however, the cortical thickness and the length is similar to control

increased volumetric bone mineral density ( J:141536 )

• increased volumetric bone density

decreased bone mass ( J:141536 )

• the body weight adjusted bone size was lower

• the magnitude of bone size phenotype is significantly enhanced by presence of Ghrhr^lit allele

limbs/digits/tail

decreased diameter of femur ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the femur are reduced; however, the cortical thickness and the length is similar to control

decreased diameter of tibia ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the tibia are reduced; however, the cortical thickness and the length is similar to control

Genotype
MGI:3823055

cx5

• Allelic Composition: Ghrhr^lit/Ghrhr⁺; M14104Asr/M14104Asr⁺
• Genetic Background: C57BL/6J-Ghrhr^lit M14104Asr

growth/size/body

decreased body weight ( J:141536 )

skeleton

decreased diameter of femur ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the femur are reduced; however, the cortical thickness and the length is similar to control

decreased diameter of tibia ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the tibia are reduced; however, the cortical thickness and the length is similar to control

increased volumetric bone mineral density ( J:141536 )

• increased volumetric bone density

decreased bone mass ( J:141536 )

• the body weight adjusted bone size was lower

• the magnitude of bone size phenotype is significantly enhanced by presence of Ghrhr^lit allele

limbs/digits/tail

decreased diameter of femur ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the femur are reduced; however, the cortical thickness and the length is similar to control

decreased diameter of tibia ( J:141536 )

• significantly slender bones

• both periosteal and endosteal circumference and cross-sectional area at the mid shaft of the tibia are reduced; however, the cortical thickness and the length is similar to control

Genotype
MGI:4431047

cx6

• Allelic Composition: Ghrhr^lit/Ghrhr^lit; Prlr^tm1Cnp/Prlr^tm1Cnp
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6J

homeostasis/metabolism

decreased circulating glucose level ( J:95779 )

• at P7 and 3 months of age, serum glucose levels are lower than in wild-type mice unlike either single homozygote

• at 12 months, female mice exhibit decreased serum glucose level compared with wild-type mice or Prlr^tm1Cnp homozygotes

increased circulating glucose level ( J:95779 )

• at 12 months in fasting male mice

increased circulating insulin level ( J:95779 )

• at P7, plasma insulin levels are decreased compared to in wild-type mice

• adult female mice exhibit decreased fasting insulin levels compared to in wild-type mice

decreased circulating insulin-like growth factor I level ( J:95779 )

• at P7

increased circulating leptin level ( J:95779 )

• in fasted female mice and fed male mice

impaired glucose tolerance ( J:95779 )

• in aged male mice

insulin resistance ( J:95779 )

• at 12 and 18 months in male mice

growth/size/body

decreased lean body mass ( J:95779 )

decreased body weight ( J:95779 )

• at P7, mice weigh less than wild-type mice unlike either single homozygote

• however, by 600 days male mice exhibit normal body weight

slow postnatal weight gain ( J:95779 )

• up to 1 year of age, female mice exhibit a reduced body weight gain compared with wild-type mice that is similar to in Ghrhr^lit female mice

• until 160 days of age, male mice exhibit decreased body weight gain compared with wild-type mice

increased susceptibility to age related obesity ( J:95779 )

• aged male mice

skeleton

short femur ( J:95779 )

decreased bone mineral density ( J:95779 )

adipose tissue

increased total body fat amount ( J:95779 )

• body fat as a percent of body weight in male mice is increased compared to in wild-type mice

• aging female mice exhibit increased percent body fat compared with wild-type mice

behavior/neurological

abnormal eating behavior ( J:95779 )

• in male mice at 15 months of age

limbs/digits/tail

short femur ( J:95779 )