Introduction to animal embryology

Duration

25h 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

Adaptation of teaching commitments following the COVID-19 pandemic for the May-June 2020 session

Teaching methods implemented : distance-learning

Distance Learning. The lessons are recorded via camstasia and MP4 videos are updated during the lessons scheduled on the e-campus portal. A forum has been opened on the ecampus portal and the teacher is available by e-mail to answer questions from students.

Assessment subjects

The entire syllabus and powerpoint is subject for examination. I give you tips and exceptions (but apart from these exceptions, everything else is part of the material).
The historical powerpoint of embryology is not part of the matter.
- Cell determination, diversification and differentiation (tips: determinant, selector gene and difference between the three cellular evolutions, not matter: epigenetics, micro-RNA)
- Sex determination, gametogenesis and fertilization (not matter: parthenogenesis)
I could ask you to compare two models of development in terms of the structure of the egg of these models, their segmentation, the development of the nervous system or their extraembryonic annexes (if they have any). It's super tip.
- Sea urchin model (tip: segmentation, gastrulation, not matter: development after gastrulation)
- Drosophila model (pipe: structure of the egg and asymmetry of the constituents, determination of the anteroposterior axis, homeotic genes, no matter: determination of the ventro-dorsal axis)
- Danio rerio fish model (tip: segmentation and map of presumptive territories)
- Xenopic amphibian model (tube: structure of the egg, segmentation and blastopore lip, not matter: cellular movements during gastrulation)
- Gallus domesticus bird model (tip: development of the egg in the female genital tract, structure of the egg and extra-embryonic appendages)
- Model of mammal, the human (pipe: segmentation of the embryo, not matter of examination: cellular movements during gastrulation)
- Become 3 sheets (pipe: lung and mesoderm development, no examination material: neural crest cells and pharyngeal arches).
- The extra-embryonic appendages of Mammals (the chorion, the embryonic cavities, the development of the placenta, its role and mother / child exchanges are tips, not matter: the evolution of the weight of the placenta during pregnancy and the development of the vesicle yolk)

- Stem cells and technologies related to developmental biology (PMA, chimerism, induced pluripotent stem cells, embryonic stem cells, adult stem cells are pipes, I will not ask about therapeutic, reproductive cloning, genetic engineering and organoids). I could ask you to explain what is fertilization by ICSI or IVF, to compare the two, to give me a definition of chimerism or to compare the therapeutic interest of the different types of stem cells (embryonic, adult or induced) . I told you in the first lesson, I will not ask a question about the time of the development stages. There is no need to remember them in detail. On the other hand, I could ask you about "which model is developing the fastest" model A or model B? ". I hope I have answered your questions on the subject. I am available by email if you need additional details.

Assessment methods

Online multiple choice questionnaire (+1 for correct answer, 0 if no answer, -0.25 if wrong answer)
Open questions online
Schemes to annotate online
The MCQ will be worth for 30% of the points, the diagrams for 20% and the open questions for 50%.
Several different questionnaires will be planned.
Please note that the open questions cannot be copied from the course.

Contacts

Virginie.gridelet@uliege.be

Adaptation of teaching commitments following the COVID-19 pandemic for the Aug-Sept 2020 session

Assessment subjects

Idem que pour juin

Assessment methods

Idem que pour juin

Contacts

Virginie.gridelet@uliege.be

Items online