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#centriole

3 public questions tagged with this topic.

Fertilization in mammals-iv

Sperm centriole contributes to:

Mammalian zygote requires centrosome to assemble mitotic spindle for first cleavage. Human oocyte lacks functional centrioles after pachytene elimination, so paternal contribution is essential. Proximal centriole introduced by sperm at fertilization recruits maternal pericentriolar material including gamma-tubulin, pericentrin and centrin to regenerate functional centrosome. This centrosome duplicates and nucleates microtubules organizing syngamy and first bipolar spindle aligning parental genomes. Without sperm centriole, parthenogenetic embryos often display abnormal spindles. It does not mediate zona digestion or mitochondrial energy production, but provides microtubule organizing center initiating embryonic cell divisions and polarity establishment.

Ref: Palermo et al., Human Reproduction 1994 & Schatten, Cell Motil 1994: Paternal centriole reconstituting centrosome for first spindle.

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Fertilization in mammals-iv

Sperm exclusively contributes:

Human oocyte centrioles degenerate during oogenesis, leaving mature egg lacking functional centrosome. Fertilizing sperm introduces proximal centriole, often with atypical structure, which recruits maternal pericentriolar material to reconstitute active centrosome in zygote. This centrosome nucleates microtubules and organizes first mitotic spindle, ensuring accurate segregation of parental genomes during cleavage. Mitochondria, ribosomes, Golgi and endoplasmic reticulum are predominantly maternal due to oocyte cytoplasmic abundance and active degradation of paternal mitochondria via ubiquitin-proteasome and autophagy, establishing maternal inheritance pattern for mitochondrial DNA and ooplasm.

Ref: Albert et al., Molecular Biology of the Cell, Chapter 20: Centrosome inheritance - paternal centriole contribution and mitochondrial degradation.

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