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This programme is an introduction to the course and represents the first material which the student should receive. It therefore leads not only the unit but the whole course. Professor David Newth ...of the University of Glasgow presents the programme after being introduced by Dr. Norman Cohen of the Open University. Professor Newth describes the early processes of development in animals and illustrates these by, time lapse film of the development of salamander and frog eggs. The processes of fertilization, cleavage, gactrulation and cytodifferentiation are described and illustrated. Research work carried out by Dr. Anne McLaren of the Institute of Animal Genetics, Edinburgh, has shown the aggregation of separate embryos of genetically different mice and the development of the aggregate into a single tetraparental mouse. Dr. McLaren demonstrates the technique of these experiments on film and explains the proceedure and results in commentary. Professor Newth describes the reverse of Dr. McLaren's experiment viz. the formation of twins and illustrates this by time lapse photography of the creation of twin salamander embryos. The programme concludes with a reference to the process of growth and the lack of understanding of the mechanisms associated with this area.
Metadata describing this Open University video programme
Item code: S2-5; 01
First transmission date: 22-07-1973
Published: 1973
Rights Statement:
Restrictions on use:
Duration: 00:24:21
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Producer: Jim Stevenson
Contributors: Norman Cohen; Anne McClaren; David Newth
Publisher: BBC Open University
Keyword(s): Cleavage; Course introduction; Cytodifferentiation; Early development in animals; Fertilisation; Formation of twins; Gastrulation; Mice genetics; Salamander and frog eggs; Time lapse
Footage description: Norman Cohen introduces the programme. He stresses the importance of the home experiment kit and the television component for this course. Shots of a tetra-parental mouse. Commentary by David Newth explains how this was achieved in the laboratory. Newth describes the field of study of the developmental biologist. He then lists some of the developmental features common to all animals. Shots of toad eggs and an adult toad. Shot of a human egg at time of conception. Shots of fully developed human nerve cells. Newth discusses the developmental features above in detail (growth, morphogenesis, cell proliferation, cell differentiation) Shots of several types of egg cells. Shots of spermatozoa. Newth explains some of the consequences of fertilisation (Genetic information derived from both parents, redistribution of cytoplasmic content of the egg, stimulate division in the zygote.) Shots of cell mitosis. Commentary by Newth explains the significance. Newth with a tank containing adult African toads. He explains why amphibia are used to study the early development of animals. Newth holds up a model of a fertilised amphibian egg. He describes its features. Film sequence using time-lapse photography shows the early history of an amphibian. Cleavage through several divisions of the egg is shown. Newth describes some of the characteristics of cleavage.The group of cells thus formed in the blastula. Shot of a mouse blastula. Newth uses a diagram to illustrate the inside of the blastula. The cells are still undifferentiated. Newth uses another diagram to illustrate and describe a technique for discovering what the cells from any part of the blastula become in the adult organism. Film sequence shows Dr. Anne McLaren performing an experiment to create a tetra-parental mouse. Her commentary explains each step of the way. Characteristics of the parents and the offspring are given and shown. Newth describes the technique for splitting an embryo at the 2 cell stage to form twins which develop separately. Film sequence shows the technique in the laboratory on an amphibian embryo. Newth begins a discussion of the gastrulation process. He describes its characteristics. Time-lapse film sequence shows gastrulation in progress. Commentary by Newth explains what is happening. Newth with a diagram which shows an embryo in the gastrulation stage. He explains a possible cause of cell differentiation which takes place from this stage onward. Further time-lapse shots showing the gastrulation process. Describing the characteristics of growth. Newth discusses possible ways in which the growth of the animal is limited at the adult stage.
Master spool number: 6HT/70908
Production number: 00525_1019
Videofinder number: 2821
Available to public: no