OBJECTIVE To assess ovarian response among carriers of FMR1 premutation who undergo preimplantation genetic diagnosis (PGD). DESIGN Retrospective study. SETTING Academic IVF unit. PATIENT(S) Of 18 carriers of FMR1 premutation referred to PGD, eight had <100 CGG repeats and ten had >or=100 CGG repeats. INTERVENTION(S) Controlled ovarian stimulation (COH) and PGD. MAIN OUTCOME MEASURE(S...

Although global erasure of DNA methylation has been observed in zygotes and primordial germ cells, the responsible enzyme(s) have been elusive. The demonstration that members of the Tet (ten eleven translocation) family of proteins are capable of catalyzing conversion of 5-methylcytosine (5mC) of DNA to 5-hydroxymethylcytosine (5hmC) raises the possibility that Tet proteins may participate in t...

BACKGROUND Chilling injury occurs when the cell membrane undergoes a transition from the liquid state to the gel state. Human oocytes and single-cell zygotes are of similar shape and size but the post-thawing survival rate of oocytes is poorer. We set out to investigate the possible difference in membrane lipid phase transition (LPT) temperature between the two cell types. METHODS The LPT tem...

The CRISPR/Cas9 system is capable of editing multiple genes through one-step zygote injection. The preexisting method is largely based on the co-injection of Cas9 DNA (or mRNA) and guide RNAs (gRNAs); however, it is unclear how many genes can be simultaneously edited by this method, and a reliable means to generate transgenic (Tg) animals with multiple gene editing has yet to be developed. Here...

Sensitivity to ultraviolet (UV) radiation (UV-A, lambda = 315-400 nm; plus UV-B, lambda = 280-315 nm) of zygotes of the brown alga Fucus serratus L. (Phaeophyta) has been assessed through effects on growth of developing germlings. Different stages of development were distinguished by considering 5 h periods of time after fertilisation. Both the stage of the zygote and the UV radiation condition...

The relative contributions of cell polarity and nuclear position in specifying the plane of asymmetric division in fucoid zygotes were investigated. In zygotes developing normally, telophase nuclei were positioned parallel to the polar growth axis, and the division plane bisected both axes. To assess division plane specification, the colinearity of the nuclear and growth axes was uncoupled by t...

Cytoplasts with diameters of 40-45, 50-55 and 70-75 microm, derived from mouse oocytes at the germinal vesicle, metaphase II and zygote stages were incorporated into zygotes by electrofusion. Manipulated (n = 867) and culture-control (n = 1114) embryos were cultured in vitro and transferred to pseudo-pregnant recipients at the blastocyst stage. When synchronous cytoplasts measuring 40-45 and 50...

Mitochondrial ribosomal RNAs (mtrRNAs) have been reported to translocate extra-mitochondrially and localize to the germ cell determinant of oocytes and zygotes in some metazoa except mammals. To address whether the mtrRNAs also localize in the mammals, expression and distribution of mitochondrion-encoded RNAs in the mouse oocytes and zygotes was examined by whole-mount in situ hybridization (IS...

The cell wall of 24-h zygotes of Fucus serratus is composed of 3 layers--an inner fibrillar layer (sulphated fucan), an outer fibrillar layer (alginic aicd/cellulose) and an exterior amorphous layer (sulphated fucan, alginic acid). The 2 layers containing sulphated fucan are preferentially thickened at the rhizoid pole. Light- and electron-microscope autoradiographic pulse-chase experiments on ...

BACKGROUND The CRISPR/Cas9 system is increasingly used for gene inactivation in mouse zygotes, but homology-directed mutagenesis and use of inbred embryos are less established. In particular, Rosa26 knock-in alleles for the insertion of transgenes in a genomic 'safe harbor' site, have not been produced. Here we applied CRISPR/Cas9 for the knock-in of 8-11 kb inserts into Rosa26 of C57BL/6 zygot...