for all biological science

1. 2. Cell

2. 2. Cell
 Common physiological denominator
 All physiological system for example, digestive, respiratory, or
cardiovascular depends on the action and activities of cell.
 The group of cell and their products coalesce to create the four basic
tissue type (epithelial, neural, muscular, and connective tissue).
 The primordial stem cell stage of the embryo, cells acquire varying
degree of structural and functional differentiation.
 Differentiation of cells equips them for particular function

3.  For many years, the dogma was that once cells become
differentiated it was impossible to reprogram them cell, so that these
cell or their daughters could be induced to follow a different path.
 However, it is also evident that advances in cell and molecular
biology have called their dogma in question
 For example, development of the cloned sheep Dolly in 1996 was
achieved using cultured fibroblasts.
 There is a lot in the news lately about stem cells. Much of this
involves efforts to produce replacement tissues or organs or combat
revenges of cancer and other disease.

4. “Typical” Animal Cell

5. CELL – Considered a basic unit of life, complex function in
multicellular animal requires interaction and cooperation between cells. cell
cell
TISSUE – Groups of cells with same general function e.g., muscle, nerve
tissue
ORGAN – Two or more types of tissues dedicated to particular function
e.g., skin, kidney, intestine, blood vessels
organ
ORGAN SYSTEM – Several organs
e.g., respiratory, digestive, reproductive systems
system

6. Terminologies
Histology: Subspecialty of anatomy that deals with the microscopic
structure of tissues.
Tissue: A group of similar cells and intercellular material specialized
to carry out a specific activity. The four primary tissues are
epithelial, muscle, nervous and connective tissue.
Organ: A discrete portion of the body composed of two or more tissue
types dedicated to a particular function.
Cytology: Subspecialty of anatomy that deals with the structure and
functional differentiation of individual cells either as isolated cells
or as part of a tissue.

7. Pathology: Subspecialty of anatomy and physiology that deals with
changes in gross anatomy, histology, or cytology associated with
disease or injury.
Necropsy: Refers to the gross and or/microscopic examination of
organ, tissue, and cells after death.
Parenchyma: Refers to the functional portion of a tissue or organs.
Stroma: Refers to the support cells, that is, connective tissue, blood
vessels, and nerves, that are needed for the parenchyma tissue to
Cary out its function.

8. Cell Parts
Organelles

9. Cell Membrane
 Outer membrane of cell
that controls movement in
and out of the cell
 Double layer

10. Nucleus
Directs cell activities with in the cell
Separated from cytoplasm by nuclear
membrane
Contains genetic material - DNA

11. Nuclear Membrane
 Surrounds nucleus
 Made of two layers
 Openings allow material to
enter and leave nucleus

12. Chromosomes
 In nucleus
 Made of DNA
 Contain instructions for
traits & characteristics

13. Nucleolus
 Inside nucleus
 Contains RNA to build
proteins

14. Cytoplasm
Gel-like mixture
Surrounded by cell membrane
Contains hereditary material

15. Endoplasmic Reticulum
 Moves materials around in cell
 Smooth type: lacks ribosomes
 Rough type (pictured):
ribosomes embedded in
surface

16. Ribosomes
 Each cell contains
thousands
 Make proteins
 Each of the cell has two sub
units identified based on
size as 18s and 28s RNA.

17. Mitochondria
 Produces energy through chemical
reactions – breaking down fats &
carbohydrates
 Controls level of water and other
materials in cell
 Recycles and decomposes proteins,
fats, and carbohydrates

18. Golgi Bodies
 Protein 'packaging plant'
 Move materials within the cell
 Move materials out of the cell

19. Lysosome
 Digestive 'plant' for proteins,
fats, and carbohydrates.
 Transports undigested material
to cell membrane for removal.
 Cell breaks down if Lysosomes
explode.

20. Animal Stem Cell

21. Stem Cell
 Stem cells are master cells with two important characteristics
 Unspecialized cells capable of their own renewal
 Ability to differentiate into different cell types
 The stem cells may have various differentiation potentials
 Totipotent
 Pluripotent
 Multipotent
 Unipotent

22.  Cells that can develop into
any other cell are called
stem cells
 A few still exist in the
body of an adult
 E.g. bone marrow has
blood stem cells
 E.g. umbilical cords have
stem cells

23. Totipotent and pluripotent cells
 In simple animals (e.g. sponges)
the cells retain their capacity to
regenerate into whole new
sponge – (Totipotent)
 More complex animals lose this
capacity
 Cells of the early embryo are
capable of turning into any type
of cell - (pluripotent)
 Differentiated cells may not be
able to do this

24. Types of stem cells
 Embryonic stem cells
 Adult stem cells

26. Characteristics of Embryonic stem cells
 Derived from Blastocyst
 Pluripotent
 Long-term self-renewal
 Exhibit and maintain a stable diploid normal complement
of chromosome

27. Characteristics of Adult stem cells
 Long-term self-renewal
 Give rise to mature cells having characteristic
morphologies and specialized functions
 Rare
 Dispersed in tissues throughout the body
 Origin of adult stem cells in tissues is yet not known

28. Tissues containing adult stem cells
 Bone marrow
 Skeletal muscle
 Epithelia of skin and digestive system
 Cornea retina
 Peripheral blood
 Spinal cord
 Blood vessels
 Testes
 Liver
 Pancreas
 Kidney
 Heart, etc

29. Stem cells specialty
 Apoptosis
No apoptosis in stem cells
 Telomere
No shortening of telomere in stem cells
 DNA Methylation
Minimum DNA methylation in stem cells

30. Major Applications
 Animal model testing for pharmaceutical research
 Use of stem cells in transplantation and cell replacement therapy
 Conservation of endangered species
 Understanding fundamental events in embryonic development
 Therapeutic delivery system
 To resolve mysteries of developmental biology
 To investigate genes involved in differentiation and development
 Cell banking for research applications

31. Making stem cells
 Stem cells could be used to replace tissues that are damaged or
diseased. E.g. cardiac muscle will not divide once it has
differentiated.
 Stem cells stimulated to grow into cardiac cells could replace
the need for heart transplants.
 The problem of tissue typing and tissue rejection still remains
 Implanted tissue could become cancerous

32. Cloned stem cells
 If stem cells can be cloned from the cells of a patient
they can be used to generated genetically identical
tissues.
Therapeutic cloning
 Mammalian cells need to be set back to the beginning
of the cell cycle.

33. Somatic cell nuclear transfer
 SCNT
 Made famous by Dolly the sheep
 Oocytes (unfertilised egg cells) harvested
 Nuclei removed
 Somatic cells from animal to be cloned fused
with enucleate oocyte
 Electric shock sets the cell cycle to G0
 Nuclear genome cloned but…
 Mitochondrial genome comes from animal
which donated the oocyte

34. Identification of stem cells
 Cell morphology
 Expression of unique cell surface antigens
 Characterization of biochemical markers such as tissue
specific enzymatic activity
 Expression of genes that are unique to a particular cell type
 Nuclear chromosomal karyotype to access genetic stability

35. Scope
 Pharmaceuticals: diabetes, cardiac anomalies, neurodegeneration,
and infertility
 Neutraceuticals: produce heterologous nutrients
 Understanding early embryonic development
 Model for in vitro drug and immunity screening
 Producing environment friendly animals eg. Phytase and methane
 Tissue remodeling and engineering
 Cell-cell communication and differentiation
 Conservation

36. Livestock stem cells
 Farm animals are contributing in human health through
 Nutrition
 Producing biomedicine
 Cell therapy
 Xenotransplantation
 With decoding of the genome sequences in animals, stem cell
promise to resolve many mysteries of the developmental
biology