Hello, my name is Dan Lindsley,
and this is the introductory
lecture to this series on
Drosophila genetics and biology.
I'm going to try to summarize the results
of the first 25 years of work on
Drosophila genetics, but before I do that
I would like to introduce you to the fly.
As you can see from this slide,
the fly is a small organism, but
one pair in a confined space can produce
50 to 100 progeny in two weeks' time.
This slide shows two pictures
of adult flies, the upper one is
a dorsal view of a male and
the lower one a lateral view of a female.
These are typical insects,
they have three body parts, the head,
the thorax, and the abdomen.
The thorax contains three pairs of legs,
and in most insects two pairs of wings,
but in the Diptera the posterior
pair of wings is replaced by a small
mechano-sensory organ known as
the haltere or the balancer.
The male's wings are spread to provide
a good view of the of the veination
which is a constant feature of
the wings and subject to mutation.
I now want to proceed to discuss
the body parts one at a time.
First being the head, the upper left-hand
picture is the head of a wild-type fly,
a major feature of the head is
the large red compound eye,
it's composed of some 800 unit eyes or
ommatidia, which are arranged
in a hexagonal array.
Anterior to the eye are the antennae,
and below are the mouth parts,
the head also contains
a specific set of bristles.
Eye mutations involve several features
of the eye, eye color as shown
in the white mutant, or eye texture
as shown in the rough-eye mutant
where the arrangement of the ommatidia
becomes completely destroyed.
In the bottom row are three
eye mutants which affect
both size, shape, and texture of the eye.