مبادئ علم الأجنة التجريبيZoo. (424)

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Transcript مبادئ علم الأجنة التجريبيZoo. (424)

‫بسم هللا الرحمن الرحيم‬
Zoo. (424)‫مبادئ علم األجنة التجريبي‬
Principle of Experimental Embryology
‫مقدمة ولمحة تاريخية‬
INTRODUCTION AND HISTORICAL REVIEW
‫محتويات المقرر‬
Course title: Principles of Experimental embryology
Zoo 424
Objective
2 hours
2(1 + 1)
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.
Lecture:1 -
Course Content: Introduction, course contents and
First week
requirements
-
lecture : 2
Theory: A historical overview of experimental embryology
Cellular differentiation and embryonic induction:
(A1- Cellular Differentiation and Determination
lecture:3
-
Second
week
Factors that control cell differentiation:
2- Embryonic induction:
-
Definition of Embryonic Induction
-
3-Embryonic Organizer
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In amphibians, birds, and mammals
-
Conclusions of embryonic induction
lecture:4
Lecture:5
Embryonic and cancer cells :
Third
week
Fourth
week
Sixth week
Cancer cells/'theories of carcinogenesis
Similarities between embryonic cells and cancer cells
lecture:6
Birth defects: Teratology
Seventh
week
The critical period of fetal development. Experimental studies Factors
that cause birth defects in of embryos.
Exam: 1
First exam from lecture 1-6 (10 marks)
Eight
week
Lecture:7
Parthenogenesis :
Nine week
-
Lecture:8
The concept of parthenogensis reproduction / Artificial
parthenogensis.
Artificial insemination (AI) and In vitro fertilization(IVF):
-
Types of artificial insemination /Collection of sperm/egg
10th Week
‫ حين‬424 ‫تابع محتويات المقرر النظري‬
Lecture:8
10th Week
Artificial insemination (AI) and In vitro fertilization(IVF):
-
Types of artificial insemination /Collection of sperm/egg
.Artificial insemination in laboratory and farm animals.
11th week
lecture 9
-
In vitro fertilization (ICSI) in humans and babies test tube.
Lecture:10
Applied studies on embryos
12th week
Lecture :11
-Production of twins and Cloning.
13th week
-Embryonic and somatic stem cells.
3rd Exam
Term paper topic presentation (10 marks).
2ndExam
From lecture from 7 to 11 (10 marks)
Theory
1-
1-
14th Week
15th week
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
‫الموقع للمقرر‬
Lab Course content: Principles of Experimental Embryology 2(1+1) (Zoo 424)
Week /Lab .no
‫ حين‬424 ‫محتوى العملي لمقرر‬
Principles of Experimental embryology
Zoo (424 ) Practical content:(2hr per lab per week)
Practical :I
Tools and devices used in experimental embryology labs.
Practice: II
Micro tube preparation :Hair loop and needles pull micro tubes .
Practical: III
Activate the ovaries with hormones in the frog
Practice :IV
Superovulation of frog: Activate ovaries by the pituitary gland .
Practice :V
Chick embryo : Making a window on chicken embryo
Practice :VI
The Shell cover chicken embryo development
Practice :VII
Whole mount slide of chicken embryo
Practice: VIII
Teratology :Effect of some factor affected embryos.
Practical: IX
Reproductive Cycle :Vaginal smear oestrus cycle detection
Practice: X
In vitro fertilization (IVF) :Superovuolation and in vitro
fertilization in mice.(Sperm and ova collection and )
Practical : XI
Embryo transfer : Collection and transfer of embryos
Practical XII
Embryo Staining :Staining mammalian embryos (Cleavage).
Practical XIII
Visiting or attending of applied Embryology lab (e.g IVF unit)
Practical XIV
The Final Exam : (20 marks) +Weekly reports 10 marks =30 marks
Reference book
Title :Embryonic Technologies/ by Ahmed Al Himaidi/ King Saud
University Press/2012/1433H.
http://fac.ksu.edu.sa/ahimaidi ‫ حين‬424 ‫مراجع المقرر‬
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 10th 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
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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).... ‫خلق من ماء دافق‬،‫فلينظر الإنسان مما خلق‬
‫ "خيرج من بني الصلب والرتائب‬Yes 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 stage: from these 3
embryonic layers were all the organs of the embryo
will form.
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 ‫فروع علم االجنة‬
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 
developmental stages. It helps to understand the
fundamental developmental mechanisms. In
experimental embryology the various parts of
developing embryo are removed, transplanted,
parts exchanged or the environmental conditions
altered. This helps to understand induction,
gradient system, etc. Experimental embryology is
also called casual embryology of analytical
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
(384 – 322 B.C ):
Before the 17th 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.
1- Aristotle
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.
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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 targetderived trophic signals, identified as nerve growth-stimulating
factor, later named nerve growth factor (NGF).
10-Ross Granville Harrison (1870 – 1975)
He successfully cultured frog neuroblasts in a lymph medium
and thereby took the first step toward current research on
precursor and stem cells. 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 DNA was found in
chromosomes 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 cell differentiation. Brachet later demonstrated
papers that differentiation is preceded by the formation of
new ribosomes and accompanied by the release from the
nucleus of a wave of new 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.