Previous studies analysing the incidences of mitochondrial DNA (mtDNA) deletions and mtDNA content in unfertilized oocytes in relation to donors' age have been controversial. The objective of the study was to compare these two parameters in unfertilized oocytes and relate them to the donors' age. Fifty-two women donated 155 unfertilized metaphase II (MII) oocytes. The incidence of 4977 bp delet...

Unfertilized human oocytes were obtained from women in an in-vitro fertilization programme. The women had a mean age of 29.4 years (range 24-35 years). Chromosomal complements could be analysed in 50 oocytes. Q-banding of the chromosomes facilitated identification of individual chromosomes: 34 oocytes (68%) had the normal haploid chromosomal complement, 14 complements were hypohaploid (28%), 1 ...

To clarify the relationship between mitochondria and embryo development, we collected human unfertilized oocytes, early embryos, and arrested embryos. Unfertilized oocytes and poor-quality embryos were collected, and the ultrastructure of mitochondria was determined by transmission electron micrography. Four criteria for determining the mitochondrial state were mitochondrial morphology, cristae...

The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing 14C-labeled phospholipids and 3H-labeled triolein, as donor particles and cross-linked ery...

The endogenous lectin of Xenopus laevis oocytes, unfertilized eggs, and blastula-stage embryos was immunohistochemically localized using a highly specific antiserum. Each tissue was examined with several techniques, including paraformaldehyde or glutaraldehyde fixation, frozen or plastic sections, and immunofluorescence or immunoperoxidase staining. In oocytes and unfertilized eggs, lectin was ...

Recent reports have suggested that when unfertilized oocytes with a spermatozoon after intracytoplasmic sperm injection (ICSI) are properly activated, the activated oocytes develop normally similar to fertilized oocytes. However, human oocytes do not easily respond to universal activators of mammalian oocytes like ethanol or calcium ionophore A23187, which induce a calcium transient in ooplasm....