Introduction to animal embryology

Duration

20h Th

Number of credits

Lecturer

Virginie Gridelet

Language(s) of instruction

French language

Organisation and examination

Teaching in the second semester

Schedule

Schedule online

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

Educational project
The main project I am considering for this course is to enable students to understand how, from the fusion of two gametes of two different individuals, a new being can be created, formed, developed, grown up and finally "perfect Through the evolution of different species.  
First part
 
During the first class, the process of meiosis will be described in detail as well as the formation of male and female gametes. Spermatogenesis and oogenesis will be explained for mammals. The next course, fertilization will be explained as well as the specific intra-species recognition of the spermatozoon by the oocyte. In the continuity of this fertilization, we will see the segmentation of embryonic cells, the formation of the morula and the blastocyst as well as the first cellular differentiations. Subsequently, the implantation of the embryo and the development of the different extra-embryonic appendages will be considered. These elements are crucial because the embryo depends on it for its survival and growth.
 
The ontogeny of different classes (sea urchin, insect, amphibian, bird and mammal) will be analyzed specifically during three theoretical courses. A good understanding of the embryonic development makes it possible to conceive more intuitively the anatomical and cellular organization characteristic of these organisms. The recapitulation will be approached, it is a theory in biology of the evolution of the development developed by Ernst Haeckel which wants that the ontogeny of an organism passes by stages representing the ancestral species of this one. Haeckel summarized the theory with the phrase "ontogeny recapitulates phylogeny".
 
The analysis of these developments during a participatory course will allow students to grasp the common points and fundamental inter-class differences. During this course, students will work in small groups to reconstruct a timeline for each of the five classes. These five lines of time will be paralleled on a wall of the local to be able to have a global overview of the various embryonic developments next to each other. Students will have the opportunity during this course to appropriate the material in a different way than ex cathedra.
 
Part Two - Development at the cellular level
 
The first chapter of this part will explain how from a cell, different cells can appear and thus globally how development unfolds at the cellular level. Diversification and cell differentiation will be described in detail.
 
A chapter will be devoted to stem cells because it is from them that the various cell types and organs develop for the constitution of an individual. During this chapter, we will study cell differentiation as well as the key players in this differentiation (transcription factors and inductive proteins, developmental regulatory genes, genetic support at the beginning of embryonic development ...). This course is considered as the last of the first part because it makes it easier to make the transition with the second part of the program.
 
The last chapter of this second part will be devoted to genetic manipulation in animals, gene therapy with stem cells and therapeutic cloning. Each of these explanations will be accompanied by one or two concrete examples already produced in research or clinical laboratories. It is interesting for students to be able to deal with applied science in developmental biology because there is a good chance that they will be confronted in their internship or their work later on.

Learning outcomes of the learning unit

Educational goals:
 
To know how to explain:
- spermatogenesis and oogenesis
- fertilization and intra-species recognition
- the 2 types of segmentation
- embryonic implantation
- placentation
- gastrulation and the different modes
- the fate of the 3 embryonic leaves
- the development of the sea urchin
- the development of an insect
- the development of amphibians
- the development of birds
- the development of mammals
- the differences between these developments
- the different types of cells: totipotent, multipotent, unipotent
- genetic control of cell differentiation
- technically possible genetic manipulations for the modification of expression of a protein by a cell or a whole organism + to be able to give a concrete example
- therapeutic cloning
- pre-implantation diagnosis + example of illness

Ability to describe and annotate on a diagram:
- a spermatozoon
- an oocyte
- an amphibian egg
- a bird's egg
- an oocyte
- a blastocyst
- the different extra-embryonic appendices
- an embryo at the time of gastrulation
- the various leaflets of the development
- the notochord, the neural plate, the mesomers

To be able to argue:
- on the inter-class differences between the different types of embryonic developments
- the use of techniques for modifying organisms for therapeutic or basic research purposes
- on the limits that the law gives to science in the selection of human embryos and in genetic modifications carried out on animals

Prerequisite knowledge and skills

Planned learning activities and teaching methods

Ex-cathedra classroom course and participatory course where students have to take stock of different types of development and present it to the rest of the class.

Mode of delivery (face-to-face ; distance-learning)

Presence request

Recommended or required readings

Books used to write the syllabus :
 
- Atlas of Descriptive Embryology - Gary C. Schoenwolf - 7ème édition - PEARSON - 2008
- Biologie du développement - Albert Le Moigne, Jean Foucrier - 7ème édition - DUNOD - 2009

Assessment methods and criteria

Open questions and multiple choice questions, each counting for 50% of the final mark.
MCQs do not have a certainty coefficient but:
- If just answer = 1 point
- If false answer = -0.25 point
- If no answer = 0

Work placement(s)

No work placement

Organizational remarks

Contacts

virginie.gridelet@uliege.be

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