05. Cloning

• parthenogenesis = type of asexual reproduction where the egg develops in absence of sperm

  • doesn't occur naturally in mammals
• there in no paternal imprinting and double maternal imprinting in parthenogenesis
• embryo splitting = artificially splitting an embryo at the 8 cell stage when the cells are totipotent

  • reproductive cloning
• mitochondrial dna is circular double-stranded dna with no introns

  • 100 fold higher mutation rate than dna
  • maternally inherited
• somatic cell nuclear transfer (SCNT) = transplanting nuclei from adult cell into oocyte/embryo to create a clone

  • nuclear dna the same mitochondrial dna is different
• scnt issues = most die in gestation

  • enlarged placentas, respiratory distress, metabolic disorders
• MST = maternal spindle transfer

  • nuclear material removed from oocyte and transferred into enucleated donated oocytes then fertilised with sperm
• PNT = pronuclear transfer

  • oocytes fertilised with sperm to create an embryo
  • nuclear material removed and transferred into donated embryo
  • donated embryo formed from donor egg and sperm