Age-dependent aneuploidy in mammalian oocytes instigated at the second meiotic division

• Ageing severely affects the chromosome segregation process in human oocytes resulting in aneuploidy, infertility and developmental disorders. A considerable amount of segregation errors in humans are introduced at the second meiotic division. We have here compared the chromosome segregation process in young adult and aged female mice during the second meiotic division. More than half of the oocytes in aged mice displayed chromosome segregation irregularities at anaphase II, resulting in dramatically increased level of aneuploidy in haploid gametes, from 4% in young adult mice to 30% in aged mice. We find that the post-metaphase II process that efficiently corrects aberrant kinetochore-microtubule attachments in oocytes in young adult mice is approximately 10-fold less efficient in aged mice, in particular affecting chromosomes that show small inter-centromere distances at the metaphase II stage in aged mice. Our results reveal that post-metaphase II processes have critical impact on age-dependent aneuploidy in mammalian eggs. 

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)

Nyckelord

Aged

Aneuploidy

Animals

Chromosome Segregation

Female

Humans

Mammals

Meiosis

Mice

Oocytes

Spindle Apparatus

anaphase

animal cell

animal experiment

animal model

Article

cell aging

centromere

controlled study

developmental disorder

gamete

infertility

kinetochore

mammal

meiotic spindle

metaphase

microtubule

mouse

nonhuman

oocyte

time lapse imaging

animal

genetics

human

age-dependent aneuploidy

chromosome

second meiotic division

segregation

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)