Learning objectives
The Course aims at imparting basic notions about the morphological traits and the structure-function relationship of the primary types of human tissues. The Student will further gain knowledge about 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 gather a basic knowledge about the morphology, classification and functional peculiarities of the primary tissues of the human body and how these can be determined in situ. The Students are also expected to acquire a thorough understanding of the primary cellular phenomena controlling early embryonic development. By also familiarizing with the technologies that may be used for analyzing these phenomena and various aspects of cellular behavior, 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 improvement of communication 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 of the primary techniques used to study cells. It is also expected that the Student has a sufficient background on the basic principles of genetics, biochemistry, cellular physiology and molecular biology.
Course unit content
The Course is divided in two main parts (Modules): one dealing with the structural and functional characteristics of human tissues, from a histological standpoint (for a total of 3 CFU), and one treating fundamental aspects of Developmental Biology. The part related to the structure and function of human tissues is organized in histology laboratories where Students are given the opportunity to independently examine histological specimens of representative human tissues. For these laboratory activities, Student are subdivided in 3 groups of 20 students each and each group will have a laboratory session each week. Thus, each group will have a laboratory event every three weeks, for a total of 8 events. The groups are created by simply dividing the class in 3 groups following alphabetical order. Each laboratory session is introduced by a brief theoretical presentation of the types of tissues planned to be examined in that session.
The second part of the Course (Module) related to Developmental Biology 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, albeit without entering into the detailed mechanisms of segmentation, and continues with a discussion on 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 such as: 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 and of the skeletal muscle and its innervation is established. The course is concluded with a discussion on the formation of the heart and the vascular system.
Full programme
Il programma relativo alle esercitazioni del primo Modulo del Corso che tratta la “Struttura e Funzione dei Tessuti Umani” comprende:
1. Una panoramica sulle metodologie, tecniche e procedure utilizzate per studiare i tessuti e le cellule che li compongono;
2. Una spiegazione delle basi per la classificazione dei tessuti umani;
3. Lo studio di tessuti epiteliali e delle membrane basali ad essi associate;
4. Lo studio della struttura e principali caratteristiche morfologiche dei tessuti connettivi lassi e le proprietà della matrice extracellulare tipica di questi tessuti;
5. Lo studio della struttura e principali caratteristiche dei tessuti connettivi propriamente detti e le proprietà della matrice extracellulare di questi tessuti;
6. Lo studio delle diverse tipologie e caratteristiche dei tessuti cartilaginei;
7. Lo studio del tessuto osseo;
8. Lo studio degli elementi del sangue e sistema ematopoietico;
9. L’approfondimento delle principali caratteristiche delle strutture vascolari e linfatiche
Il secondo Modulo del Corso dedicato alla Biologia dello sviluppo tratta i seguenti argomenti:
1. Il processo di segmentazione e i primi stadi di sviluppo;
2. La definizione del ciclo vitale dell’embrione dei vertebrati;
3. Il processo di gastrulazione e il suo controllo cellulare e molecolare;
4. I meccanismi molecolari alla base della determinazione dei foglietti embrionali: endoderma, mesoderma e ectoderma;
5. I meccanismi molecolari alla base per la specificazione degli assi corporei: dorsale-ventrale e anteriore-posteriore;
6. I meccanismi cellulari e molecolari alla base per la specificazione della simmetria bilaterale;
7. Il fenomeno dell’induzione del tessuto nervoso e dell’epidermide ed i meccanismi cellulari e molecolari che controllano la neurulazione
8. I meccanismi cellulari e molecolari che sottendono alla formazione del tubo neurale, lo sviluppo del sistema nervoso centrale e l’innervazione della muscolatura;
9. I meccanismi cellulari e molecolari che controllano la formazione e sviluppo della cresta neurale ed i suoi derivati;
10. I meccanismi cellulari e molecolari che sottendono alla formazione delle somiti e del dermo-miotomo e lo sviluppo di questa struttura in muscolo scheletrico e cartilagine;
11. I geni che controllano la delineazione della struttura corporea (il “codice Hox”)
12. I meccanismi cellulari e molecolari che controllano la formazione degli arti;
13. I meccanismi cellulari e molecolari che sottendono alla formazione del cuore e del sistema vascolare.
I relativi capitoli consigliati dal libro di testo di rifermento, “Principi dello Sviluppo di Wolpert e coautori, sono i seguenti:
Capitolo 1. Le origini della biologia dello sviluppo e gli strumenti concettuali.
Capitolo 3. Sviluppo dei vertebrati I: cicli di sviluppo e tecniche sperimentali. Cicli vitali dei vertebrati e cenni di sviluppo.
Capitolo 4. Lo sviluppo dei vertebrati II: Xenopus e pesce Zebra.
Capitolo 5. Sviluppo dei vertebrati III: pollo e topo, il completamento del piano corporeo.
Capitolo 9. La morfogenesi: cambiamenti di forma dell’embrione precoce.
Capitolo 12. Lo sviluppo del sistema nervoso. Specificazione dell’identità cellulare nel sistema nervoso.
I corrispettivi capitoli e approfondimenti consigliati dal libro di testo complementare e di supporto, “Biologia dello sviluppo” di Gilbert e Barresi, sono i seguenti:
Capitolo 1. Costruzione di nuovi organismi; meccanismi di organizzazione dello sviluppo
Il ciclo della vita; un esempio: la vita di una rana; embriologia comparata; Visione d’insieme delle fasi iniziali dello sviluppo; seguendo le cellule in movimento: mappe presuntive e discendenze cellulari.
Capitolo 2. Specificazione dell’identità; Meccanismi di modellamento dello sviluppo; Livelli di impegno; Specificazione autonoma; Specificazione condizionale; Specificazione sinciziale; Un arcobaleno di identità cellulari
Capitolo 4. Comunicazione fra cellule; Meccanismi di morfogenesi; Adesione e riassortimento cellulare; la segnalazione iuxtacrina e la fisica della morfogenesi; La matrice extracellulare come fonte di importanti segnali dello sviluppo; Transizione epitelio-mesenchimale; Segnalazione cellulare; Fattori paracrini: le molecole induttrici; La biologia cellulare del segnale paracrino; Segnali iuxtacrini nell’identità cellulare
Capitolo 11. Anfibi e pesci; Primi stadi dello sviluppo degli anfibi; Fecondazione, rotazione corticale e segmentazione; La gastrulazione degli anfibi; Determinazione progressiva degli assi degli anfibi; Il lavoro di Hans Spemann e Hilde Mangold; Meccanismi molecolari della determinazione degli assi negli anfibi; La specificità regionale dell’induzione neurale lungo l’asse antero-posteriore; Specificazione dell’asse destro-sinistro
Capitolo 12. Uccelli e mammiferi; Primi stadi dello sviluppo negli uccelli; La segmentazione; La gastrulazione negli embrioni degli uccelli; Specificazione degli assi e dell’“organizzatore”
negli uccelli; Primi stadi dello sviluppo nei mammiferi; La segmentazione; La gastrulazione nei mammiferi; Formazione degli assi dei mammiferi
Capitolo 13. Formazione e modellamento del tubo neurale; La trasformazione della piastra neurale in un tubo: come nasce il sistema nervoso centrale; Il modello “insegui e metti in fuga”; Lo scheletro del cranio derivato dalla cresta neurale; La cresta neurale cardiaca; L’ontogenesi dei percorsi assonali nel sistema nervoso; Il cono di crescita: guida e motore dell’esplorazione assonale alla ricerca di un percorso (axon pathfinding); La guida assonale; Il programma di navigazione intrinseco dei neuroni motori (motoneuroni); Come fanno i neuroni motori ad attraversare la strada?
CAPITOLO 14. Lo sviluppo dell’encefalo; Neuroanatomia dello sviluppo del sistema nervoso
Centrale; I meccanismi dello sviluppo che regolano l’accrescimento del cervello; Sviluppo del cervello umano
Capitolo 17. Mesoderma parassiale; I somiti e i loro derivati; I tipi cellulari della somite; Determinazione del mesoderma parassiale e dei destini cellulari lungo l’asse antero-posteriore; La somitogenesi; Sviluppo dello sclerotomo; Sviluppo del derma miotomo.
Bibliography
The recommended textbook for the first part of the Course is "Histology: A Text and Atlas", by Micheal H. Ross and Wojciech Pawlina, published by Lippincott Williams & Wilkins. As the Course teaches ground level notions of functional histology, there are numerous other books that the Students may consult to grasp the same concepts. Students may therefore opt for the adoption of an alternative textbook to conduct their studies.
For the second part of the Course, the recommended textbooks 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 a complementary textbook, the Students are also encouraged to consult the 11th edition of the book “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 specifically treat concept embodied by the following chapters of these books.
For "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
The Course’s objective is to transmit to the Student a comprehensive understanding of the morpho-functional characteristics of human tissues and how they are created during development. The Course addresses therefore 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 textbooks with authentic illustration, while assuring that this material is readily accessible to the Students through publication on the university portal Elly.
Because of this invaluable contribution made by the Lecturer based on 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. Lectures are normally recorded and access to these recordings is given to working Students and Students that because of documented health problems or strong family impediments have not been able to attend lectures.
Assessment methods and criteria
Participation at ALL histology laboratories (a total of 8) is mandatory for completion of the Course.
Participation at the Lectures of the second Module of the Course is also mandatory. Students are therefore highly encouraged to attend the Lectures to assure the maximal gain. At the end of these, laboratories, there will be an optional test based on the recognition and description of 3 tissue slides. For the correct description of ONE of the 3 tissues the Student receives ONE EXTRA POINT to be added to the vote obtained for the second Module of the Course. In case of correct recognition/description of at least TWO of the tissues, the Student receives 2 points to be added to the vote for the second Module.
Completion of the Module related to Developmental Biology is based on the evaluation of a short presentation given on a subject picked out randomly by the Student from 40 possible ones. 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 5 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 5 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.
Other information
The first part of the Course dealing with functional histology is organically coordinated with the parallel Course in Human Anatomy and Histology held by Prof. Cecilia Carubbi. Hence, histological characteristics of different tissues are treated separately, but in a complementary manner, by the two courses.
2030 agenda goals for sustainable development
The Course aims at reaching primarily the Objectives 4), 5), 11) and 17) of the 2030 Agenda for substainable growth.
