Phenotypes associated with this allele

• Allele Symbol: Ccnb3^em1Sky
• Allele Name: endonuclease-mediated mutation 1, Scott Keeney
• Allele ID: MGI:6287726
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ccnb3^em1Sky/Ccnb3^em1Sky	involves: C57BL/6J * CBA/J	MGI:6287820
ot2	Ccnb3^em1Sky/Y	involves: C57BL/6J * CBA/J	MGI:6287821

Genotype
MGI:6287820

hm1

• Allelic Composition: Ccnb3^em1Sky/Ccnb3^em1Sky
• Genetic Background: involves: C57BL/6J * CBA/J

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

reproductive system

reproductive system phenotype ( J:273304 )

♀N • at 3 months of age, female homozygotes exhibit normal folliculogenesis and oocyte counts relative to heterozygous female controls

abnormal polar body morphology ( J:273304 )

• oocytes from most (71 of 79) mutant mice fail to extrude a polar body after germinal vesicle breakdown (GVBD)

abnormal female meiosis ( J:273304 )

♀ • oocytes appear normal until metaphase I but show a highly penetrant failure to transition to anaphase I; however, ~10% of mice harbor oocytes able to progress through meiosis I

♀ • whereas control oocytes separate their chromosomes and extrude polar bodies 8 h after germinal vesicle breakdown (GVBD), mutant oocytes remain in a metaphase I-like state, with a spindle that has migrated to the cortex and chromosomes aligned at the spindle mid-zone

♀ • oocytes arrest in metaphase I with aligned bivalents, bipolar spindles, partial anaphase-promoting complex/cyclosome (APC/C) activation, high CDK1 activity, high securin and cyclin B1 protein levels, and little or no separase activity

female infertility ( J:273304 )

• female homozygotes are sterile; no pregnancies are observed, and no pups are born from mutant females bred with wild-type males for two rounds of mating

cellular

abnormal polar body morphology ( J:273304 )

• oocytes from most (71 of 79) mutant mice fail to extrude a polar body after germinal vesicle breakdown (GVBD)

abnormal female meiosis ( J:273304 )

♀ • oocytes appear normal until metaphase I but show a highly penetrant failure to transition to anaphase I; however, ~10% of mice harbor oocytes able to progress through meiosis I

♀ • whereas control oocytes separate their chromosomes and extrude polar bodies 8 h after germinal vesicle breakdown (GVBD), mutant oocytes remain in a metaphase I-like state, with a spindle that has migrated to the cortex and chromosomes aligned at the spindle mid-zone

♀ • oocytes arrest in metaphase I with aligned bivalents, bipolar spindles, partial anaphase-promoting complex/cyclosome (APC/C) activation, high CDK1 activity, high securin and cyclin B1 protein levels, and little or no separase activity

Genotype
MGI:6287821

ot2

• Allelic Composition: Ccnb3^em1Sky/Y
• Genetic Background: involves: C57BL/6J * CBA/J

reproductive system

reproductive system phenotype ( J:273304 )

♂N • surprisingly, hemizygous males are fertile with no detectable meiotic abnormalities