The development of mouse embryos formed by the aggregation of four 8-cell-stage eggs was analysed in comparison with control single embryos. The analysis revealed that: Quadruple aggregates undergo size regulation over several days, starting before implantation and being completed by 6.5 days post coitum. The attainment of recognizable postimplantation morphological stages is independent of siz...

When mouse embryos at early stages are aggregated and cultured in vitro, they form a morula and, eventually, a blastocyst which is roughly proportional in size to the number of embryos which contributed to it (Tarkowski, 1961; Mintz, 1965). Cell counts have shown that blastocysts derived from two 8-cell stages contain twice the number of cells of normal blastocysts (Bowman & McLaren, unpublishe...

Two-cell mouse embryos were cultured in vitro for different periods in a medium in which NaCl was partially replaced by LiCl at concentrations ranging from 1 to 30 mM. The relative cell number diminished according to increasing LiCl concentrations but the onset of blastulation was not affected, thus resulting in blastulae with fewer cells than normal and with a reduced or absent inner cell mass...

BACKGROUND The present study was undertaken to ascertain whether the polarized flow of cells from polar to mural trophectoderm is related to the axis of bilateral symmetry of the blastocyst in the mouse, and whether trophectoderm cells can initiate new cycles once they have left the polar region. METHODS AND RESULTS Two different approaches were used to investigate the relationship of polar t...

A key challenge of single-cell RNASeq (scRNASeq) is the many genes with zero reads in some cells, but high expression in others. Modelling zeros using the Michaelis-Menten equation provides a superior fit to existing scRNASeq datasets compared to other approaches and enables fast and accurate identification of features corresponding to differentially expressed genes without prior identification...

This paper reports studies on the effects of re-vitrification by the CPS (Closed Pulled Straw) method on the development of 4-cell stage mouse embryos. The procedure involved culturing 2-cell mouse embryos in G-1 medium until the 4-cell stage followed by the division of the normal 4-cell stage embryos into a control group (non-vitrified) and two experimental subgroups (vitrified and re-vitrifie...

A common feature of early vertebrate embryos is that they are surrounded by a simple protective epithelial cell layer. However, it is currently not well understood how the differentiation of this epithelium is controlled. We present data showing that BMP4 is sufficient to promote differentiation of this epithelium in diverse vertebrates. In mouse embryos the outer epithelium forms the trophecto...

Cultured mouse blastocysts produce plasminogen activator, a protease that converts the zymogen plasminogen into the trypsin-like enzyme, plasmin. We have fractionated the blastocyst and cultured the constituent cell types. Trophoblast outgrowths free of inner cell mass derivatives secrete plasminogen activator during a time period that closely parallels the invasive phase of trophoblast cells i...

abstractl-carnitine (lc) is an antioxidant with the ability to promote the growth in vitro embryo.objective: the goal was to evaluate the effect of lc on some indicators of embryo development and blastocyst quality including zona pellucid (zp) thickness, the hatching of blastocysts and their cell numbers.materials and methods: mouse embryos were randomly divided into five groups and incubated w...

The single-phase flow and thermal performance of a double pipe heat exchanger are examined by experimental methods. The working fluid is water at atmospheric pressure. Temperature measurements at the inlet and outlet of the two streams and also at an intermediate point half way between the inlet and outlet is made, using copper-constantan thermocouple wires. Mass flow rates for each stream are ...