Drosophila melanogaster
Drosophila melanogaster
General information about Drosophila
melanogaster
Physical appearance
Drosophila melanogaster as a model
organism in genetics
Genetic markers and its examples
Genome
Similarity to humans
General information
Drosophila melanogaster is a species of
Diptera, or the order of flies, in the family
Drosophilidae
Drosophila melanogaster = fruit fly =
vinegar fly
This species is a model organism that is
widely used for biological research in
studies of genetics, physiology, microbial
pathogenesis and life history evolution
It is typically used because it is an animal
species that is easy to care for, breeds
quickly, and lays many eggs
General information
Drosophila melanogaster was among the
first organisms used for genetic analysis,
and today it is one of the most widely used
and genetically best-known of all
eukaryotic organisms
All organisms use common genetic
systems. Comprehending processes such
as transcription and replication in fruit flies
helps in understanding these processes in
other eukaryotes, including humans
Physical appearance
Model organism in
genetics
Drosophila melanogaster is one of the most
studied organisms in biological research,
particularly in genetics and developmental
biology. There are several reasons:
Its care and culture requires little
equipment and uses little space even when
using large cultures, and the overall cost is
low
It is small and easy to grow in the
laboratory
It has a short generation time
Model organism in
genetics
It has a high fecundity
Males and females are readily distinguished
and virgin females are easily isolated,
facilitating genetic crossing
It has only four pairs of chromosomes
Males do not show meiotic recombination,
facilitating genetic studies
Its complete genome was sequenced and
first published in 2000
Genetic markers
Genetic markers are commonly used in Drosophila
research and most phenotypes are easily identifiable
either with the naked eye or under a microscope
Drosophila genes are traditionally named after the
phenotype they cause when mutated
Examples of common
markers
w1: white
Eyes lack
pigmentation and
appear white
Examples of common
markers
y1: yellow
Body pigmentation
and wings appear
yellow. This is the fly
analog of albinism
Examples of common
markers
e1: ebony
Black body and
wings
Examples of common
markers
Cy1: Curly
The wings curve away from the body, flight
may be somewhat impaired
Sb1: stubble
Bristles are shorter and thicker than wild
type
Genome
The genome of Drosophila melanogaster
contains four pairs of chromosomes: an X/Y
pair, and three autosomes labeled 2, 3, and
4
Its sequenced genome of 139.5 million
base pairs has been annotated and
contains approximately 15,016 genes
More than 60% of the genome appears to
be functional non-protein-coding
DNA involved in gene expression control
Genome
Determination of sex in Drosophila occurs
by the ratio of X chromosomes to
autosomes, not because of the presence of
a Y chromosome as in human sex
determination. Although the Y chromosome
is entirely heterochromatic, it
contains at least 16 genes, many of which
are thought to have male-related functions
Similarity to humans
About 75% of known human disease genes
have a recognizable match in the genome
of fruit flies and 50% of fly protein
sequences have mammalian homologs
Drosophila is being used as a genetic
model for several human diseases including
the neurodegenerative disorders
Parkinson's, Huntington's, spinocerebellar
ataxia and Alzheimer's disease
The fly is also being used to study
mechanisms underlying aging and
oxidative stress, immunity, diabetes, and
cancer, as well as drug abuse
The end