ميحرلا نمحرلا الله مسب

Zoo. (424)

يبيرجتلا ةنج لا ملع ئدابم Principle of Experimental Embryology

ة ي خ ي ر ا ت ة ح م ل و ة م د ق م I N TR OD U C TI ON A N D HI S TOR I C A L R EVI EW

Zoo 424

ررقملا تايوتحم

Course title: Principles of Experimental embryology 2 hours 2(1 + 1) Objective The aim of this course is to provide the student with basic information about experimental embryology that led to understand the process of embryonic cell differentiation and organogenesis of embryos development .Study some applied experiment on embryos.

L ecture:1 Course Content :

Introduction, course contents and requirements

Theory:

A historical overview of experimental embryology

lecture : 2 Cellular differentiation and embryonic induction: (A1- Cellular Differentiation and Determination -

Factors that control cell differentiation:

lecture:3 2- Embryonic induction: lecture:4 -

Definition of Embryonic Induction -

3-Embryonic Organizer

In amphibians, birds, and mammals Conclusions of embryonic induction

Lecture:5 lecture:6 Exam: 1 Embryonic and cancer cells :

Cancer cells/'theories of carcinogenesis Similarities between embryonic cells and cancer cells

Birth defects: Teratology

The critical period of fetal development. Experimental studies Factors that cause birth defects in of embryos.

First exam from lecture 1-6 (10 marks) First week Second week Third week Fourth week Sixth week Seventh week Eight week Nine week Lecture:7 Parthenogenesis : -

The concept of parthenogensis reproduction / Artificial parthenogensis.

Lecture:8 Artificial insemination (AI) and In vitro fertilization(IVF): -

Types of artificial insemination /Collection of sperm/egg

10 th Week

نيح 424 يرظنلا ررقملا تايوتحم عبات

Lecture:8 Artificial insemination (AI) and In vitro fertilization(IVF): lecture 9 -

Types of artificial insemination /Collection of sperm/egg .Artificial insemination in laboratory and farm animals. -

In vitro

fertilization (ICSI) in humans and babies test tube.

Lecture:10 Applied studies on embryos Lecture :11 -

Production of twins and Cloning. -Embryonic and somatic stem cells.

3 rd Exam Term paper topic presentation (10 marks).

2 nd Exam From lecture from 7 to 11 (10 marks) 10 th Week 11 th week 12 th week 13 th week 14 th Week 15 th week Theory

1-

1- Experimental Embryology :

by Ahmad Rashed Al Himaidi and Saleh Abdulaziz Karim / King Saud University Press,2008.

References Books.

2-Developmental Biology "

by Scott F. Gilbert 2003 7th ed .Sinauer Association Inc. Sunderland Massachusetts's.

http://fac.ksu.edu.sa/ahimaidi ررقملل عقوملا

Week /Lab .no Practical :I Practice: II Practical: III Practice :IV Practice :V Practice :VI Practice :VII Practice: VIII Practical: IX Practice: X Practical : XI Practical XII Practical XIII Practical XIV Reference book

نيح

Principles of Experimental Embryology 2(1+1)

424 ررقمل يلمعلا ىوتحم

Principles of Experimental embryology (Zoo 424) Zoo (424 ) Practical content:(2hr per lab per week) Tools and devices

used in experimental embryology labs.

Micro tube preparation

:Hair loop and needles pull micro tubes .

Activate the ovaries

with hormones in the frog

Superovulation of frog

: Activate ovaries by the pituitary gland .

Chick embryo

: Making a window on chicken embryo

The Shell cover

chicken embryo development

Whole mount slide

of chicken embryo

Teratology

:Effect of some factor affected embryos.

Reproductive Cycle

:Vaginal smear oestrus cycle detection

In vitro fertilization (IVF)

:Superovuolation and

in vitro

fertilization in mice.(Sperm and ova collection and )

Embryo transfer

: Collection and transfer of embryos

Embryo Staining

:Staining mammalian embryos (Cleavage).

Visiting

or attending of applied Embryology lab (e.g IVF unit)

The Final Exam

: (20 marks) +Weekly reports 10 marks =

30 marks Title :Embryonic Technologies /

by Ahmed Al Himaidi/ King Saud University Press/2012/1433H.

http://fac.ksu.edu.sa/ahimaidi نيح 424 ررقملا عجارم

1 Theory References Books.

1- Experimental Embryology :by Ahmad Rashed Al Himaidi and Saleh Abdulaziz Karim / King Saud University Press,2008.

2-Developmental Biology "by Scott F. Gilbert 2014 10 th ed .Sinauer Association Inc. Sunderland Massachusetts's.

Lab Reference book

Title :Embryonic Technologies/ by Ahmed Al Himaidi/ King Saud University Press/2012/1433H.

Principal of Experimental Embryology (Zoo 424): Introduction and historical review

     

The embryology science reported by some verses of the Quran in particular with regard to human creation "

so let man see, create, creation of water flush from between back bone and ribs,(altraeb)

بئارتلاو بلصلا نيب نم جرخي قفاد ءام نم ....

قلخ امم ناسنلإا رظنيلف ،قلخ " Yes it is God sinah in this life, All multicellular organisms arose from the mating between male and female gametes ( fertilization ) Note the embryos in different developmental stages from gamete to cleavage (from Zygote to blastula stage). Then Gastrulation stage, the formation of the three different embryonic layers, ectoderm,mesoderm and endoderm( gastrula ).

Later the organogensis embryonic layers were all the organs of the embryo will form.

stage: from these 3 Finally the grow and increase in size until the exit of the embryo for life ( hatching or birth ).

Introduction

: The development of multicellular organisms from a single cell — the fertilized egg — is a brilliant thinking .

During embryonic development, the egg divides to give rise to many millions of cells ,which form structures as complex and varied as eyes,arms, and brain. This amazing achievement raises many questions. -How do the cells arising from division of the fertilized egg become different from each other? -How do they become organized into structures such as limbs and brains What controls the behavior of individual cells so that such highly organized patterns emerge? -How are the organizing principles of development embedded within the egg, and in particular within the genetic material, DNA?

?

-Much of the excitement in developmental biology today comes from our growing understanding of how genes direct these developmental processes, and genetic control is one of the main themes of this course. -Several of factors are involved in controlling development, but we will focus only on those that have key roles and illustrate general principles. -The development of an embryo from the fertilized egg is known as

embryogenesis .

One of its first tasks is to lay down the overall body plan of the organism, and we shall see that different organisms solve this fundamental problem in several ways.

Branches of Embryology ةنجلاا ملع عورف

Embryology has many sub-branches in it. They are: 

1- Descriptive Embryology

   It is applied to the method of study concerned with the direct observation and description of embryological development. Embryology in ancient times started as a branch of study based on the direct observation and description by scientists like Aristotle (340 B.C.), Fabricius (1537 – 1619), Harvery (1578 – 1657) and so on.

2- Comparative embryology

It is the embryological development of different animals and studied and compared. Comparative embryology throws much light on the understanding of evolution and phylogenetic significance. It also give some ideas on the developmental stages of certain animals in whose case the study of development is different.

3- Experimental Embryology

 In it is experiments are used for studying the fundamental developmental mechanisms. In experimental embryology the various parts of altered. This helps to understand induction, also called casual embryology of analytical  developmental stages. It helps to understand the developing embryo are removed, transplanted, parts exchanged or the environmental conditions gradient system, etc. Experimental embryology is embryology. Wilhelm Roux (1850 – 1924) is the pioneer in the field of experimental embryology.

4- Chemical Embryology

The developmental stages are studied by biochemical and physiological techniques. It is also called physiological or biochemical embryology.

Needham (1931)

is the pioneer in this field.

5- Teratology

It is a branch of embryology concerned with the study of malformations or abnormal development.

6- Developmental Biology

It includes not only embryonic development but also postnatal processes such as normal and neoplastic growth, metamorphosis, regeneration and tissue repair in both animal and plant .

Historical and background of Experimental Embryology 1 Aristotle (384 – 322 B.C

): Before the 17 th century embryological knowledge was based on the writings of Aristotle and Galen. Embryology as a branch of biology was initiated by the famous Greek philosopher Aristotle (384 – 322 B.C.). He was the first embryologist to describe the development and reproduction of many kinds of organisms in

his book entitled "Degeneratione Animalium

". He believed firmly that the complex adult organism develops from a simple formless beginning.

Cont. Historical and background of Exp. Embryology cont. Aristotle (384 – 322 B.C

): Thus he laid the foundation for the basic principles of epigenesist, a theory postulated after 2000 years. For this Aristotle is honored as the father of embryology. Aristotle has written that the male contributes the semen and the female contributes the contamenia. The semen is secreted by testis and it is hot and active. The catamenia is carried through very fine vessels into the uterus. It is equivalent to the menstrual blood. He had no knowledge of ovary. He thought that the female reproductive system is formed of uterus only and not of anything else.

Cont .Historical and background of Embryology 2 Wilhelm Roux (1888)and Hans Driesch1892

Both In separate experiments,

Wilhelm Roux (1888) and Hans Driesch (1892)

set out to determine whether epigenesis or preformation was correct. Both allowed a fertilized egg to divide to the two-cell stage. Roux, using amphibian embryos (frogs, toads, salamanders), killed one of the two cells with a hot needle. Driesch, using echinoderm embryos (sea stars, sea urchins, sea cucumbers), completely separated the divided cells.

Cont .Historical and background of Embryology Cont. Wilhelm Roux (1888)and Hans Driesch (1892)

An entire animal developing from a single cell would support epigenesis. A portion of the animal developing would favor preformation. What was the result? Interestingly, Roux described the formation of a half embryo that he called a “hemiembryo” (figure

a

), and Driesch found that each cell retained the potential to develop into an entire organism (figure

b

).

3-August Weismann 1880s

Propose that the germ plasma theory : The egg and sperm contribute chromosomes equally to the zygote (fertilized egg). The chromosomes are carriers of the hereditary potentials, and the germ cells (gametes) of the embryo are the only ones to carry the complete set of hereditary potentials (nuclear determinants), whereas each somatic (body) cell type contains only part of these potentials required for the specific cell type .

   

4-Oscar Hertwig (1872)

He repeat the Wilhelm's experiments, but he separate the 2 cell frog embryo from them and improved that each cell had a potential to grow, but the embryo result is half size than normal embryo. This experiment is considered the one of explanations of twins formation result from one egg.

5-Theodor Boveri (1902)

He studied the effect of nucleus and cytoplasm on the development of the sea urchin fertilized ovum by study of centriol and filaments formation during different division stages. Also, he tries to insemination of specific species ovum with another species sperm, and he found that the chromosomes are different in quantity and numerically.

6- Thomas Hunt Morgan (1866 – 1945)

 He is the first scientist that suggested that the embryonic development is controlled by expressions of different genes, and he awarded Nobel prize for discovered the mutations in Drosophila and their role in understand the role of genes in heredity.  

7- Otto Warburg (1908 – 1910)

He studied the respiratory mechanism in sea urchin embryo cells, and he considers the first scientist who definition oxygen consumes in respiratory of ovum and embryonic cells. Their study resulted in know that the fertilization make to increase the cellular reparatory rate of fertilized ovum. So, he discovered the cytochrome Oxidase and he awarded the Nobel prize on this discovery at 1931.

    

8- Ernest E. Just (1883 – 1941)

He descrip the changes occurred around the oocytes during the fertilization in sea urchin and he studied the parthenogenesis to understand the relationship between penetrate of sperm and the first division of Nematoda oocytes.

9-Viktor Hamburger (1954)

The discovery of chick embryo's neural sector. Hamburger proposed an antiapoptotic action of the hypothetical target derived trophic signals, identified as nerve growth-stimulating factor, later named nerve growth factor (NGF).

10-Ross Granville Harrison (1870 – 1975)

He successfully cultured frog precursor and stem cells neuroblasts in a lymph medium and thereby took the first step toward current research on . He was considered for a Nobel prize for his work on nerve-cell outgrowth, which helped form the modern functional understanding of the nervous system, and he contributed to surgical tissue transplant technique.



11-Hans Spemann and Mangold (1924)

 Hilde Mangold’s experiment involved taking a piece of the lip of the blastopore of the gastrula stage of the amphibian embryo and grafting it to the wall (flank) of another gastrula at a site distant from the host blastopore, and thereby induced a secondary axis of polarity in the host that eventually developed into a secondary embryo.

 In 1935 Spemann received the Nobel Prize for Medicine or Physiology as the first embryologist.

    

12- Jean Brachet (1988 – 1909)

In 1933 Brachet was able to show that chromosomes DNA was found in and that RNA was present in the cytoplasm of all cells. His work showed that RNA plays an active role in protein synthesis. Brachet also carried out pioneering work in the field of new cell differentiation ribosomes nucleus of a wave of new . Brachet later demonstrated papers that differentiation is preceded by the formation of and accompanied by the release from the messenger RNA .

13-Robert Briggs (1983 – 1911) and Thomas Joseph King

He was a scientist who in 1952, together with

Thomas Joseph King

, cloned a frog by nuclear transfer of embryonic cells. The same technique, using somatic cells, was later used to create Dolly the Sheep by

Willmut and Kith Kamble 1997

. Their experiment was the first successful nuclear transplantation performed in metazoans .