Extending axons in the developing nervous system are guided in part by repulsive cues. Genetic analysis in Drosophila, reported in a companion to this paper, identifies the Slit protein as a candidate ligand for the repulsive guidance receptor Roundabout (Robo). Here we describe the characterization of three mammalian Slit homologs and show that the Drosophila Slit protein and at least one of t...

This theme issue, based on a Royal Society Discussion Meeting held in April 2014, is a celebration, a reflection and a prediction. To start, we celebrate the memory of Ross Granville Harrison FRS who first showed a century ago that chicken embryo nerve cells could be grown outside the animal [1]. This was the invention needed to begin the animal cell culture industry. Adhesion to a substrate wa...

Homologous interference during Sindbis virus infection has been investigated. Prior infection of either chicken embryo fibroblast or BHK(21) cell cultures results in reduced yields of progeny virions of the superinfecting genotype. This reduction in yield results from a reduction in the number of cells in the cultures capable of producing the superinfecting genotype. The development of interfer...

Most of the systematic studies used in the development of human embryo culture media have been done first on mouse embryos. The general use of NMRI outbred mice is a model for toxicology, teratology and pharmacology. NMRI mouse embryo exhibit the two-cell block in vitro. The objective of this study was to evaluate and compare the effects of four kinds of culture media on the development of zygo...

Chick embryo chondrocytes were grown in cell culture in the presence of 5-bromo-Z’-deoxyuridine. Under these conditions, the cells attached to the tissue culture plates and became polygonal in shape and concurrently shifted their synthesis of collagen from type I1 to type I subunits. The changes in the levels of the corresponding collagen RNAs in the nucleus and cytoplasm were examined during t...

Effects of Sex Ratio Organism (SRO) on the development of embryonic cells of Drosophila melanogaster were studied in vitro. The single embryo culture technique and a histochemical staining method were employed to distinguish male embryo cultures from female ones. SRO-infected Zw(n) females were crossed to wild-type males, and their embryos were separately dissociated and cultured in vitro. Cell...

The objective of the courses which this syllabus describes is to expose developmental biologists to embryo culture and embryo manipulation techniques and applications in quantitative analyses. The laboratory program complements classroom teaching by exposure to both inductive and deductive methodologies. Developmental biology teaching requires good background in cell biology, molecular biology ...

RATIONALE This review comes at a time when in vitro embryo culture techniques are being adopted for the safe exchange and cryo-conservation of coconut germplasm. In due course, laboratory procedures may replace the options that exist among standard commercial nursery germination techniques. These, in their turn, have supplanted traditional methods that are now forgotten or misunderstood. Knowle...

Whole embryo culture techniques were used to test the effects of sodium arsenate on the rates of DNA, RNA, and protein accumulation. Rat embryos were isolated on the 10th gestational day (sperm day = Day 0) either 4 or 24 hr after maternal injection. The cultivation period was for 24 or 42 hr. DNA, RNA, and protein values were not significantly different for in utero treatment 4 hr prior to dis...