2023-2024 / BIOL0019-1

Introduction to animal embryology


25h Th

Number of credits

 Bachelor in biology3 crédits 


Virginie Gridelet

Language(s) of instruction

French language

Organisation and examination

Teaching in the second semester


Schedule online

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

The main project that I envision for this course is to allow students to understand how from the fusion of two gametes of two different individuals, a new being can be created, formed, developed, grown and finally "perfect". »Through the evolution of different species.

We will see cell determination and differentiation. Comment from a single cell (the zygote), an individual made up of 200 different cell types manage to form and set up according to the different axes of development.

Finally, technology applied to developmental biology is essential to understanding the challenges of tomorrow. What can humans do with cells or models of development?

The first chapter of this part will explain how from a cell, different cells can appear and therefore overall how development takes place at the cellular level. The processes of cell diversification and differentiation will be described with the example of different experiments explaining these processes.

A chapter will be devoted to stem cells because it is from them that the different cell types and organs for the constitution of an individual develop. During this chapter, we will study cell differentiation as well as the key players in this differentiation (transcription factors and inducing proteins, developmental regulatory genes, genetic support at the start of embryonic development, etc.). 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.

During the second part, 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 the case of mammals. In the following 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 various extra-embryonic appendages will be considered. These elements are crucial because the embryo depends on them for its survival and growth.

The ontogeny of different classes (sea urchin, insect, amphibian, fish, bird and mammal) will be specifically analyzed during several theoretical courses. A good understanding of embryonic development allows a more intuitive conception of the anatomical and cellular organization characteristic of these organisms.

The analysis of these developments during a participatory course will allow students to understand the common points and fundamental differences between classes. In this lesson, students will work in small groups to piece together a timeline for each of the five classes. These five timelines will be placed in parallel on a wall in the room to be able to have a global overview of the various embryonic developments one beside the other. Students will therefore have the opportunity during this course to appropriate the subject in a different way than the ex cathedra.

The last chapter of this second part will be devoted to genetic manipulations in animals, gene therapy carried out using stem cells and therapeutic cloning.  It is interesting for students to be able to approach applied science in developmental biology because there is a good chance that they will be confronted with it in their internship or work later.

Learning outcomes of the learning unit

Educational goals:


Know how to explain:

- cell determination

- cell differentiation

- homeotic genes

- cellular determinants

- symmetrical division

- asymmetric division

- epigenetics

- sex determination for different species

- 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 layers

- the development of the sea urchin

- the development of an insect

- the development of amphibians

- fish development

- 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 (for the drosophilia and the xenopus)

- technically possible genetic manipulations for modifying the expression of a protein by a cell or an entire organism + being able to give a concrete example

- the drawing of the dorso-ventral plane (Drosophila and Xenopus) and the molecules involved - the establishment of the antero-posterior plane (Drosophila and xenopus) and the molecules involved - technically possible genetic manipulations for modifying the expression of a protein by a cell or an entire organism + being able to give a concrete example - The stem cells - induced pluripotent cells - organoids

- therapeutic cloning

- pre-implantation diagnosis + example of disease


To be able to describe and annotate on a diagram:

- a sperm

- an oocyte

- an amphibian egg

- a bird egg

- an oocyte

- a blastocyst

- the various extra-embryonic annexes (birds and mammals)

- an embryo at the time of gastrulation

- the different development slips

- the notochord, the neural plate, the mesomers

- dorso-ventral axes according to the concentration of BMP and its inhibitors


To be able to argue:

- on the inter-class differences between the different types of embryonic development

- on the use of techniques for modifying organisms for therapeutic or fundamental research purposes

- on the limits that the law gives to science in the selection of human embryos and in the genetic modifications carried out on animals

- on the different levels of cell development and their future

- on the difference between cell determination and differentiation

- on the processes of cell determination and differentiation

- on the differences between the different levels of determination and differentiation

- Use of stem cells

- Use of IPS cells

Prerequisite knowledge and skills

Planned learning activities and teaching methods

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

Mode of delivery (face to face, distance learning, hybrid learning)

Face-to-face course

Additional information:


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

Exam(s) in session

Any session

- In-person

written exam ( multiple-choice questionnaire, open-ended questions )

Additional information:

True or false questions (with smart questionnaire)

Right answer = 1 point, wrong answer = -0.2, no answer = 0 point

Short open questions

Long open questions

Diagrams to annotate

Work placement(s)

No work placement

Organisational remarks and main changes to the course



Association of one or more MOOCs

Items online

2017 Slides Embryology
Presentation of slide shows for 2017

This manuscript includes al the theoretical lessons of thf the course Introduction to animal embryology.