Fate maps
Piebaldism due to mutation in KIT gene
TS of Seminiferous tubule
Spermiation
Human sperm
Human sperm in further detail
Motile apparatus of sperm
Acrosome formation
Changes in the No of germ cells in the human ovary
Growth of oocyte in frog
Schematic representation of Xenopus oocyte maturation
Oocyte in maturing stages
Cortical action in sea urchin
Cortical action in man
Fusion of egg and sperm membranes in sea urchin and mouse
Acrosome reaction in sea urchin egg
Events leading to the formation of fertilization envelop and the hyaline layer
Acrosome reaction in mammals
Formation of fertilization envelope
Wave of calcium release across sea urchin egg during fertilization
Comparison of Spermatogenesis and Oogenesis
Time line for the fertilization of sea urchin egg
Resting potential and Fertilization potential
Cleavage
• Cleavage is a series of rapid mitotic divisions whereby the enormous volume of egg cytoplasm is divided into numerous smaller nucleated cells. These cleavage stages are called blastomeres. One consequence of this rapid division is that the ratio to cytoplasmic to nuclear volume gets increasingly smaller as cleavage progresses. The rate of cell division and the placement of blastomeres with respect to one another is completely under the control of proteins and mRNAs stored in the oocyte of the mother
Cell cycle of somatic and early blastomeres
Role microtubules and microfilamenta in cell division
Summary of Holoblastic and meroblastic cleavages
Holoblastic cleavage in sea cucumber
Cleavage in sea urchin
Cytoplasmic rearranement
Fate map of frog
Cleavage of a frog egg
Spiral cleavage in molluscs
Right and Left handed coiling in snail
Bilateral cleavage in tunicates
Radial and rotational cleavage, a comparison
Development of human embryo from fertilization to implantation
Compaction, cell junction formation and cavitation
Hatching of blastocyst from zona pellucida
Timing of human monozygotic twinning with relation to extraembryonic membranes
• Fate maps of different animals
Fate map of Sea urchin
Fate map of a tunicate
Formation of syncytial cables
Fate map of Fish
Sea urchin development
Discoidal Meroblastic cleavage
Meroblastic cleavage in Zebra fish
Overview of early development of selected animals
Blastula of Zebra fish
Cleavage of frog egg
Reorganization of cytoplasm in the newly fertilized egg of frog (cortical rotation)
if we allow rotation the larva is normal, if rotation is inhibited with UVirradiation the embryo is featureless and vetralized if we treat the embryo with heavy water it will
enhance microtubule formation resulting into the formation of cyclopean eye and over
developed sucker and if we impose second rotation with centrifugation the result is
conjoined twin
Ingression of primary mesenchyme cells
Axis formation in chick
Invagination of the vegetal plate
Archenteron formation in sea urchin
Gastrulation in Zebra Fish
Fate map of frog
Asymmertry of amphibian egg
Organization of secondary axis by dorsal blastopore tissue
Exp of Nieuwkoop and Nakamura
Cell movements during frog gartrulation
Cell movement during frog gastrulation
Epiboly of ectoderm
Cell movement during gastrulation in Xenopus
Early movements of frog gastrulation
Gastrulation
• It is the process of highly integrated cell and tissue movements and their rearrangements so as to develop a three layered embryo composed of ectoderm, mesoderm and endoderm.
Types of cell movements
Cell movement in embryo of chick
Formation of blastoderm in chick
Formation of two laryered blastoderm in chick
Migration of endodermal and mesodermal cells through the primitive streak
Cell movement of P/Streak
First week of human development
Eye Development