Developmental Biology 8/e

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Chapter 9
During Drosophila development, cellular membranes
do not form until after the thirteenth nuclear
division.
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9.1 Laser confocal micrographs of stained
chromatin showing superficial cleavage in a
Drosophila embryo
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9.3 Formation of the cellular blastoderm in
Drosophila
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9.5 Gastrulation in Drosophila (Part 1)
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9.5 Gastrulation in Drosophila (Part 2)
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9.5 Gastrulation in Drosophila (Part 3)
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9.5 Gastrulation in Drosophila (Part 4)
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9.6 Schematic representation of gastrulation in
Drosophila (Part 1)
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9.6 Schematic representation of gastrulation in
Drosophila (Part 2)
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9.7 Comparison of larval and adult segmentation
in Drosophila
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9.8 The anterior-posterior axis is specified
during oogenesis (Part 1)
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9.8 The anterior-posterior axis is specified
during oogenesis (Part 2)
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9.8 The anterior-posterior axis is specified
during oogenesis (Part 3)
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9.9 Expression of the gurken message and protein
between the oocyte nucleus and the dorsal
anterior cell membrane
Since it can diffuse only a short distance,
Gurken protein reaches only those follicle cells
closest to the oocyte nucleus. This establishes
the dorsal-ventral polarity in the follicel cell
layer that surrounds the growing oocyte.
A) mRNA Gurken is located between the oocyte
nucleus and the follicle cells of the ovary. B)
Younger stage than A. C) Cross section of the egg
through the region of Gurken protein expression.
D) More mature oocyte showing Gurken across the
dorsal region.