Phenotypes associated with this allele

• Allele Symbol: Nr5a2^tm1Bel
• Allele Name: targeted mutation 1, Luc Belanger
• Allele ID: MGI:3050234
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Nr5a2^tm1Bel/Nr5a2^tm1Bel	involves: 129/Sv * C57BL/6 * SJL	MGI:3050245
ht2	Nr5a2^tm1Bel/Nr5a2^+	involves: 129/Sv * C57BL/6 * SJL	MGI:3050246

Genotype
MGI:3050245

hm1

• Allelic Composition: Nr5a2^tm1Bel/Nr5a2^tm1Bel
• Genetic Background: involves: 129/Sv * C57BL/6 * SJL

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

mortality/aging

embryonic lethality between implantation and somite formation, complete penetrance ( J:91695 )

• normal ratio of homozygotes at E6.5 but none at E10.5

• embryos undergoing resorption at E7.5

embryo

abnormal germ layer development ( J:91695 )

abnormal ectoderm development ( J:91695 )

• disorganized ectoderm at E6.5

abnormal mesoderm development ( J:91695 )

• mesoderm clustering and constriction at E7.5, defective node organize or primitive line

abnormal amniotic cavity morphology ( J:91695 )

• amniotic cavity absent or malformed

absent amniotic cavity ( J:91695 )

Genotype
MGI:3050246

ht2

• Allelic Composition: Nr5a2^tm1Bel/Nr5a2⁺
• Genetic Background: involves: 129/Sv * C57BL/6 * SJL

homeostasis/metabolism

decreased circulating progesterone level ( J:124199 )

• female heterozygotes display significantly lower progesterone levels following hormonal stimulation and during natural pregnancy relative to wild-type littermates

• progesterone synthesis is reduced after eCG stimulation; however, when eCG stimulation is followed by hCG treatment, circulating progesterone reach levels similar to those found in wild-type females

• on day 6 of gestation, the average progesterone levels of heterozygous females, either pregnant or having undergone embryo loss, is significantly lower than that observed in wild-type females

decreased circulating cholesterol level ( J:91695 )

• fasting plasma cholesterol levels reduced 14-17%

abnormal bile salt level ( J:89523 )

• bile acids are increased about 1.5X

reproductive system

reproductive system phenotype ( J:124199 )

N • female heterozygotes display normal ovarian weight, follicular development and corpus luteum formation relative to wild-type females, in the absence or presence of hormonal treatment

N • normal numbers of corpora lutea, released oocytes, implantation sites, and litter sizes are observed, indicating normal ovulation

N • normal serum levels of estrogen are observed in the absence or presence of hormonal stimulation

increased uterus weight ( J:124199 )

♀ • in response to hormonal treatment (either eCG alone or eCG + hCG), female heterozygotes exhibit significantly higher uterine weights than wild-type females, consistent with reduced serum progesterone levels after eCG stimulation

abnormal pregnancy ( J:124199 )

♀ • pregnancy loss occurs prior to 6.0 dpc specifically in female heterozygotes with the lowest progesterone levels

♀ • only 59.5% of female heterozygotes killed at 6.5 dpc display a successful pregnancy, as shown by the presence of well-developed deciduas and embryos; the remaining 40.5 % exhibit decidual resorption

reduced female fertility ( J:124199 )

♀ • only 56% of female heterozygotes mated with wild-type males have successful pregnancies

♀ • some female heterozygotes that do not support pregnancy after the first mating event are able to produce offspring on subsequent matings with wild-type males

♀ • other female heterozygotes that have a successful pregnancy after the first mating event are not always able to sustain a successful pregnancy in subsequent matings

♀ • administration of a progesterone implant, but not of an empty implant, at the beginning of pregnancy restores both the level of circulating progesterone and frequency of pregnancy to wild-type levels