Phenotypes Associated with This Genotype

Genotype
MGI:2677137

• Allelic Composition: Pes1^tm1Sad/Pes1^tm1Sad
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ

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

mortality/aging

embryonic lethality before implantation, complete penetrance ( J:80174 )

• blastomeres in homozygous null embryos arrested at preimplantation (morula) stages of development

• morulae were recovered at non-Mendelian frequencies: approximately 50% of homozygous null embryos arrested at an even earlier developmental stage

embryo

embryo phenotype ( J:80174 )

N • overall, homozygous null morulae appeared similar to wild-type embryos with evenly sized blastomeres and well-defined cell-cell borders

embryonic growth arrest ( J:80174 )

• mutant blastomeres failed to proliferate past morula stages of development, and appeared disorganized and unevenly sized

• at 3.5 dpc, electron microscopy revealed that blastomeres of homozygous null embryos failed to form well-differentiated nucleoli, although electron dense material (presumably remnants of the nucleolus precursor body) and electron dense spheres located near the nuclear periphery were readily identifiable

• high magnification revealed the presence of ribosomes in control embryos but not in homozygous null embryos: mutant embryos displayed a striking 23-fold reduction in the number of ribosomes relative to wild-type

abnormal embryonic tissue morphology ( J:80174 )

• all homozygous null embryos examined at 3.5 dpc contained only 8-16 cells (i.e. the number of cells normally observed in wild-type morulae at 2.5 dpc), and none of the homozygous null embryos had formed blastocysts