Download apoptosis basic morphogenetic processes

Basic morphogenetic processes
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Course 5: Cells and tissues
development
Course 5: Development
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137 Case report: Thalidomide
138 Basic morphogenetic processes
139 Regeneration and reparation
140 Female reproductive system
142 Gametogenesis and fertilization
144 Genetic determination of the sex
145 Signalization in development
146 Blastogenesis, notogenesis
149 Embryonic period..
151 Histogenesis
152 Human reproductive genetics
153 Developmental toxicology
154 Ageing
Aim
• mechanisms, participating during
ontogenesis, creating multicellular organism
from one cell, zygote
Oocyt + sperm = zygote
Oocyt
Oocyte and sperms
Basic morphogenetic processes:
mechanisms participating during ontogenesis, creating
multicellular organism from one cell
Zygote
Multicellular organism
• terminology, theoretical background
• normal development example
• abnormal development example
Ontogenesis – development of individual being
• begins by fertilisation (oocyte and sperm) - zygote culminates by maturity : physical, structural, functional,
sexual, mental, emotional – terminates by death
• time of birth - divides ontogenesis prenatal and postnatal
• prenatal period: 40 weeks
blastogenesis - embryonal - fetal - perinatal
0-2 weeks
3.-8.w
9.-.38.w around 40w
1. trimester
2.a 3. trimester
blastogenesis
embryonic period
fetal period
Ontogenesis - prenatal - zygote development
toward multicellular organism
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mechanisms operate…at different levels
cells - differentiation
cell populations - morphogenesis - structure development
cell populations set - morphogenetic system – realizes
structure and function programme in organ or part of the
body – basic morphogenetic processes
Cell level
• differentiaton - process that cause cell specialisation
• different cell types develop from totipotent zygote, by
specific and different proteins synthesis, underlying specific
morphology (structure) and function of particular cell
Zygote
Oocyt + sperm
Oocyt
Oocyte and sperms
Goblet cells and cilliated cells
Blood cells
Chondrocytes
Different cell types – different proteins
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Cilliated cell - tubulin a dynein
Neuron - neurotransmitter, tubulin a kinesin
B- cell of pankreas
Red blood cell - hemoglobin
Differentiation
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differentiation is dependent on signals from cell
environment (regulatory differentiation) – in case of higher
species (e.c.-human)
Differentiation and determination
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gene - RNA - DNA - protein = differentiation
regulatory genes
control the expression of one or more other genes
they are activated by the signal from environment
a cell can become specified for a particular fate – it becomes
determined – the cell fate determination
• determination is followed by differentiation
mesenchymal cell
chondroblast
cartilage
lipoblast
fat
fibroblast
osteoblast
myoblast
bone
muscle
hemocytoblast
endothelium
blood cells
connective tissue, ligaments, tendons
Diferentiation of neuroepithelium
Cell populations level
• development of structures/ organs - morphogenesis
• 1. induction – one cell population induces the change of the
fate in another cell population
• epithelial-mesenchymal interactions
examples: limbs, lens, nephrons, teeth
cross-talk
• 2. cell-signalling, signalising cell x target cell (must be
sensitive to this signal)
paracrine interactions, contact interactions
• neuroectoderm induction / target is surface
ectoderm – lens placode
Morphogenetic systems level
= group of cell populations developmental programme
• basic morphogenetic processes - 4 processes play out at the
cell population level to essentially create the final organism
• proliferation
• migration
• asociation
• programmed cell death - apoptosis
Proliferation (mitotic activity)
• characteristic feature of development – the embryo grows
+ cavity formation a extracellular material increase (interstitial
growth in cartilage) + cell increase
• considerable in embryonic period 3.-8. week , 3mm – 30 mm
• in adult tissues proliferation in regeneration process
(hematopoeisis, epithelial tissues..)
• programmed structure growth (limb is preformed as
miniature in 4th week of development, followed by its
growth)
• growth/proliferation is regulated – growth factor – insulin,
insulin-like-growth faktor, PDGF, VEGF…
• mitotic activity is localised in the centres of proliferation
Cell migration
• cell movements from original site to the target site
• passive – the cells are pushed from the proliferation centre
• activní – movements thank to cell itself systém of locomotion
(philopodium, train)
• Neural crest derived cells, germ layer cells, somites
Neural crest cell derivates
Cell association
• association to the groups, for synchronisation of their function
• CAM – cell adhesive molecules, cadherins, gap-junctions
• syncytium in skeletal muscle, neurons, angiogenesis
2 multipolar neurons associated by synapse
biomedicalengineering.yolasite.com
Apoptosis
• fysiological process
• elimination of defect cells
mutation or supranumeral
elements (neurons)
• creating of the shape interdigital spaces in hands
and feets
Limb development
• Limb bud - mesenchyme, ectoderm
• AED - apical ectodermal ridge - proliferation
• ZPA – zone of polarisation activity- retinoid acid –
morphogene – transcriptional factor- for axis pattern (SHH,
BMP, WNT, HOX genes - postion)
• differentiation – bones, connectives
• migration – muscle cells from somites, melanocytes, Schwann
cells from neural crest
• growth of axons from spinal cord , angiogenesis association• apoptosis – interdigital spaces formation
Affected limb development
• critical period 4.-7.week
• thalidomide - 20% risk of defects
phokomelia, amelia
• proximal part of limb is missing ,
stylopodium and zeugopodium
• mechanism
• block of growth factor for
angiogenesis and integrins
Neural tube differentiation in CNS development
neuroepithelial cells - proliferation, neuroblast migration,
neuron association to neuronal net. Solitary neurons die by
apoptosis
• basic morphogenetic processes - 4 processes play out at the
cell population level to essentially create the final organism
• proliferation
• migration
• asociation
• programmed cell death - apoptosis
Embryology
• developmental processes during prenatal period of
development
• morfogenesis
• organogenesis
• teratogenesis