14

Embryo Polarity and Pattern Formation

Polarity of the frog zygote

Importance of the gray crescent in frog development

Cleavage of the zygote of the sea snail, Ilyanassa

Experimental separation of cells after the 3rd cleavage in a sea urchin embryo

Spemann’s experimental transplantation of the gray crescent

Spemann’s experimental transplantation of the gray crescent

Development of vertebrate optic vesicles and their induction of lenses

Mammalian eye development

Mammalian eye development

Mammalian eye development

Amphibian gonad differentiation:

presumptive ovarian tissue

presumptive testicular tissue

undifferentiated gonad

mature ovary

mature testis

Homo sapiens genitalia differentiation

Homophilic binding of cell-adhesion proteins

A model of cell migration

Somite formation just prior to nerulation (cross section)

Somite formation just prior to nerulation (longitudinal section)

Model of morphogen concentration gradients in Drosophila differentiation of segmentation

Drosophila larval imaginal discs for corresponding adult appendages

A homeobox mutation in Drosophila

A homeobox mutation in Drosophila

Pattern formation in development of chick (Gallus gallus) wing

Pattern formation in development of chick (Gallus gallus) wing

Control development of chick (Gallus gallus) wing

Experimental grafting of progress zone in development of chick (Gallus gallus) wing

Experiment with a transplanted polarizing region

Control development of chick (Gallus gallus) wing

Regeneration of salamander arm

Migration of nerve cells

Growth cone of developing axon in grasshopper

Cell death (apoptosis) during the formation of nematode ganglion

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Tim

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mitosis