Learning objectives
The Course aims at imparting basic notions about the structure-function relationship of human tissues, how these are elaborated during development and the modes through which complex cellular and molecular interplays govern the conversion of a fertilized egg into a full organism. Students are therefore expected to gain a basic knowledge about the morphology, classification and functional peculiarities of the primary tissues of the body and how these can be examined in situ. The Students area also expected to gain a thorough understanding of the primary cellular phenomena controlling early embryonic development. By also familiarizing with the technologies that may be used for analysing these phenomena and various aspects of cellular behaviour, the Students are further assured to reach full comprehension about how the acquired knowledge can be exploited in applied terms. Through the Course Students are further instructed in the ability to collect, compile and evaluate scientific information and data in the field such to be able to make proper judgements about their validity. This will be instrumental in their development of better communications and learning skills.
Prerequisites
In relation to the first part of the Course, it is assumed that the Student has a sufficient background in cell biology and some of the techniques used to study cells.
Course unit content
The introductory section of the Course initiates with an overview of primary concepts, definition of widely used terms and the nomenclature currently adopted in the field. In the subsequent phase, the Course discusses the concept and modes of cleavage of the fertilized embryo, without entering into the detailed mechanisms, and the process of blastula formation. It proceeds with a treatment of the complex cellular, biochemical and molecular regulation of the specification of the three embryonic germ layers (endoderm, mesoderm and ectoderm) and the phenomenon of gastrulation. Particular attention is then given to the mechanisms controlling a number of other critical events ensuing early in the development: determination of the left-right symmetry, the dorso-ventral and the rostro-caudal polarities setting up for the body axis. It will then be possible to grasp the concept of cell fate determination and the molecular determinants of this phenomenon. Once clarified the process of neurulation, and how the patterning of neural progenitors is defined within the developing neural tube, the Course focuses on the formation, migration and development of the neural crest cells and the formation of the peripheral nervous system. This part of the Course is followed by a discussion of mechanisms underlying the metameric pattern of the somites (somitogenesis) and Hox genes set up the segmentation of the vertebrate body. The final part of the Course treats the formation of the limbs, the skeletal muscle and its innervation.
Full programme
The Course entails the following topics:
1. Terminology and concepts
2. The process of cleavage and gastrulation
3. Specification of the germ layers: endoderm, mesoderm and ectoderm
4. Establishment of the dorsal-ventral polarity
5. Establishment of the anterior-posterior body axis
6. Establishment of the left-right asymmetry
7. The default state of neural induction
8. The process of neurulation
9. Formation and development of the neural crest
10. Formation of the central nervous system
11. Molecular control of the establishment of the body plan – the “Hox code”
The chapters of the recommended primary text book, “Principle of Development” by Wolpert and co-authors, pertaining to these topics are:
Chapter 1 - History and basic concepts
Chapter 3 - Vertebrate development I: life cycles and experimental techniques
Chapter 4 - Vertebrate development II: Xenopus and zebrafish
Chapter 5 - Vertebrate development III: Chick and mouse - completing the body plan
Chapter 9 - Morphogenesis: change in form in the early embryo
Chapter 12 - Development of the nervous system
Relevant Chapters from the supportive, complementary text book “Developmental Biology” by Gilbert and Barresi include:
I. PATTERNS AND PROCESSES OF BECOMING: A FRAMEWORK FOR UNDERSTANDING ANIMAL DEVELOPMENT
2. Specifying Identity: Mechanisms of Developmental Patterning
Levels of Commitment
Autonomous Specification
Conditional Specification
Syncytial Specification
A Rainbow of Cell Identities
4. Cell-to-Cell Communication: Mechanisms of Morphogenesis
A Primer on Cell-to-Cell Communication
Adhesion and Sorting: Juxtacrine Signaling and the Physics of Morphogenesis
The Extracellular Matrix as a Source of Developmental Signals
The Epithelial-Mesenchymal Transition
Cell Signaling
Paracrine Factors: Inducer Molecules
The Cell Biology of Paracrine Signaling
Juxtacrine Signaling for Cell Identity
III. EARLY DEVELOPMENT: CLEAVAGE, GASTRULATION, AND AXIS FORMATION
11. Amphibians and Fish
EARLY AMPHIBIAN DEVELOPMENT
Fertilization, Cortical Rotation, and Cleavage
Amphibian Gastrulation
Progressive Determination of the Amphibian Axes
The Work of Hans Spemann and Hilde Mangold
Molecular Mechanisms of Amphibian Axis Formation
Regional Specificity of Neural Induction along the Anterior-Posterior Axis
Specifying the Left-Right Axis
12. Birds and Mammals
EARLY DEVELOPMENT IN BIRDS
Avian Cleavage
Gastrulation of the Avian Embryo
Axis Specification and the Avian "Organizer"
EARLY DEVELOPMENT IN MAMMALS
Cleavage
Mammalian Gastrulation
Mammalian Axis Formation
IV. BUILDING WITH ECTODERM: THE VERTEBRATE NERVOUS SYSTEM AND EPIDERMIS
13. Neural Tube Formation and Patterning
Transforming the Neural Plate into a Tube: The Birth of the Central Nervous System
Patterning the Central Nervous System
All Axes Come Together
14. Brain Growth
Neuroanatomy of the Developing Central Nervous System
Developmental Mechanisms Regulating Brain Growth
Development of the Human Brain
15. Neural Crest Cells and Axonic Specificity
THE NEURAL CREST
ESTABLISHING AXONAL PATHWAYS IN THE NERVOUS SYSTEM
V. BUILDING WITH MESODERM AND ENDODERM: ORGANOGENESIS
17. Paraxial Mesoderm: The Somites and Their Derivatives
Cell Types of the Somite
Establishing the Paraxial Mesoderm and Cell Fates Along the Anterior-Posterior Axis
Somitogenesis
Sclerotome Development
Dermomyotome Development.
Bibliography
The recommended text books are the Sixth Edition of “Principles of Development”, by Lewis Wolpert, Cheryll Tickle and Alfonso Martinez Arias. The Fifth Edition of this book is available translated in Italian and may be adopted as an alternative (Oxford University Press). As complementary text book, the students are also encouraged to consult the 11th edition of “Developmental Biology” by Scott Gilbert, which is also available in a translated Italian version. A copy of the presentations given through the Lectures is made available through the institutional web platform “Elly”.
The Course will specificallly concentrate on the following chapters of these books.
"Histology", chapters.."Principles of Development", Chapters: 1, 3-5, 7, 10 and 11. It is further recommended to read Chapter 8 for proper knowledge. In the case of the book "Developmental Biology" the Chapters of reference are: 1, 5, 11-15, and 17-19.
Teaching methods
To reach the Course’s objective, that is, to transmit to the student a comprehensive understanding how embryonic development is regulated at the cellular and molecular level. The Course literature has been selected such as to offer the most modern and up-to-date texts treating these topics. As the field of developmental biology is pervaded by experimental milestone articles, published in journals of major scientific impact, landmarks discoveries are extensively treated during the Lectures, often by using images from the original publications as an aid. Particular care is therefore taken to complement illustrations of the text books with authentic illustration, while assuring that this material is readily accessible to the Students through publication on the university portal Elly. Registration of the Lectures are similarly accessible by Students upon specific request to the Lecturer.
Because of this invaluable contribution made by the Lecturer and afforded by his knowledge and scientific experience in the field, it is strongly recommended that the Students attend ALL lectures and access notes taken by course mates in case of unattendance. Thus, the Course entails both traditional lecturing and some more interactive events.
Assessment methods and criteria
Attendance of the Course is mandatory and Students are therefore highly encouraged to take part at the Lectures. In case of absence, Students should make sure to access the Course mates’ notes from unattended Lectures. Course proficiency is based on an oral presentation on a topic autonomously and independently selected by the Student and strongly pertaining to the topics discussed during the Course. The Student is therefore called in to select a subject of his/her particular interest and compile a suitable Presentation of that subject. The Presentation is judged for its quality in terms of clarity, accurateness and pertinence to the selected topic. Particular attention is given to the degree of knowledge of the Student on the selected subject and how he/she articulates it. The Presentation should not exceed 10 minutes and is followed by a short discussion related to the Presentation as well as intended to assess the Student’s basic knowledge on the subject of the Course. If the Presentation is judged to be of insufficient quality and receives a low score (vote), it is possible to give another one, in a different occasion and on a different topic. This should similarly be selected autonomously by the Student.
As a thumb rule, the Presentation should entail no more than 10 slides, which should be illustrative and NOT simply report copied texts from books or articles. This means that slides should mostly report tables, graphs, images, diagrams and schemes, which may be supported by short explanatory texts. As a guideline, the Presentation should give an overview of what is currently known about the topic that is dealt, but may also treat a few up-to-date scientific articles describing highly innovative findings that may be particularly important for the field. Negative evaluations will be given to Presentations on subjects not related to the topic specifically selected by the Student; Presentations that are excessively long; Presentations that do not respect the above guidelines of how they should be organized; and Presentations that do not provide a sufficiently clear Comprehensive view on the treated subject will similarly be judged negatively. the Course.
Other information
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