Microinjection is considered the gold standard technique for delivery of nucleic acids (NAs; transgenes or genome editing tools such as CRISPR/Cas9 systems) into embryos, for creating genetically modified organisms. It requires sophisticated equipment as well as well-trained and highly skilled personnel to perform the micro-injection technique. Here, we describe a novel and simple microinjectio...

The purpose of the present study was to determine the chronology of the pre-implantation embryonic development in Myocastor coypus (coypu). It was carried out by daily colpocytological examination and controlled mating of 33 females. Oocytes and embryos were obtained by flushing from day 0 to day 10 post-coitus (p.c.). On day 1 p.c., oocytes predominated whereas on day 2 p.c. zygotes were predo...

Epigenetics regulations have an important role in fertilization and proper embryonic development, and several human diseases are associated with epigenetic modification disorders, such as Rett syndrome, Beckwith-Wiedemann syndrome and Angelman syndrome. However, the dynamics and functions of long non-coding RNAs (lncRNAs), one type of epigenetic regulators, in human pre-implantation development...

The genetic mechanisms governing human pre-implantation embryo development and the in vitro counterparts, human embryonic stem cells (hESCs), still remain incomplete. Previous global genome studies demonstrated that totipotent blastomeres from day-3 human embryos and pluripotent inner cell masses (ICMs) from blastocysts, display unique and differing transcriptomes. Nevertheless, comparative gen...

Molecular events involved in gene expression in unfertilized eggs and pre-implantation embryos are beginning to be understood. In this work, we investigated the transcription and processing of two structurally juxtaposed mouse RING finger protein genes, Rnf33 and Rnf35. Transcripts of these genes are detected only in eggs and in pre-implantation embryos. Both genes are intronless except for a s...

BACKGROUND Cryopreservation of embryos may lead to zona hardening that may compromise in vivo hatching and implantation following thawing and transfer. Assisted hatching (AH) has been advocated as a means of assisting the natural hatching process and enhancing implantation. METHODS The aim of this study was to assess in a prospective randomized manner the effect of laser-assisted hatching (LA...

Regardless of whether fertilization occurs in vivo or in vitro, a large proportion of human embryos do not develop progressively through the pre-implantation stages or arrest development after implantation. This study examined the association between the chromosomal/spindle normality of the mature human oocyte and the dissolved oxygen content, vascular endothelial growth factor concentration (V...

This study was designed to compare the efficiency of the Cryotop and Calibrated plastic inoculation loop (CPIL) devices for vitrification of rabbit embryos on in vitro development and implantation rate, offspring rate at birth and embryonic and fetal losses. CPIL is a simple tool used mainly by microbiologists to retrieve an inoculum from a culture of microorganisms. In experiment 1, embryos we...

Establishment of totipotency after somatic cell nuclear transfer (NT) requires not only reprogramming of gene expression, but also conversion of the cell cycle from quiescence to the precisely timed sequence of embryonic cleavage. Inadequate adaptation of the somatic nucleus to the embryonic cell cycle regime may lay the foundation for NT embryo failure and their reported lower cell counts. We ...