Dictyate

The dictyate or dictyotene[1] is a prolonged resting phase in oogenesis. It occurs in the stage of meiotic prophase I[2] in ootidogenesis. It starts late in fetal life[2] and is terminated shortly before ovulation by the LH surge.[3] Thus, although the majority of oocytes are produced in female fetuses before birth, these pre-eggs remain arrested in the dictyate stage until puberty commences and the cells complete ootidogenesis.

In both mouse and human, oocyte DNA of older individuals has substantially more double-strand breaks than that of younger individuals.[4]

The dictyate appears to be an adaptation for efficiently removing damages in germ line DNA by homologous recombinational repair.[5] Prophase arrested oocytes have a high capability for efficient repair of DNA damages.[5] DNA repair capability appears to be a key quality control mechanism in the female germ line and a critical determinant of fertility.[5]

  1. ^ Boron, W.F.; Boulpaep, E.L., eds. (2005). Medical Physiology. Elsevier Saunders. ISBN 1-4160-2328-3. OCLC 56191776.
  2. ^ a b National Research Council (US) Safe Drinking Water Committee; Thomas, R. D. (1986). Thomas, Richard D (ed.). Drinking Water and Health. Vol. 6. Washington, D.C.: National Academies Press. p. 35. doi:10.17226/921. ISBN 0-309-03687-9. PMID 25032465.
  3. ^ Barresi, Michael (2006). "Hormones and Mammalian Egg Maturation". DevBio: A Companion to Developmental Biology. Archived from the original on 2008-05-08.
  4. ^ Titus S, Li F, Stobezki R, Akula K, Unsal E, Jeong K, Dickler M, Robson M, Moy F, Goswami S, Oktay K (2013). "Impairment of BRCA1-related DNA double-strand break repair leads to ovarian aging in mice and humans". Sci Transl Med. 5 (172): 172ra21. doi:10.1126/scitranslmed.3004925. PMC 5130338. PMID 23408054.
  5. ^ a b c Stringer JM, Winship A, Zerafa N, Wakefield M, Hutt K (May 2020). "Oocytes can efficiently repair DNA double-strand breaks to restore genetic integrity and protect offspring health". Proc Natl Acad Sci U S A. 117 (21): 11513–22. doi:10.1073/pnas.2001124117. PMC 7260990. PMID 32381741.