it is for the education purpose

1. Submitted by:
Vineet Sharma
221/PMT/004
Submitted to:
Dr. Bhaswati Banerjee

2. Introduction:-
 Drosophila melanogaster, commonly known as the fruit fly, is a small insect that
belongs to the family Drosophilidae.
 It has been extensively studied in scientific research due to its short generation time,
ease of maintenance, and the vast amount of genetic tools available for manipulation.
 It has a relatively short life cycle, completing its development from egg to adult in
about 10-14 days under optimal conditions.
 This rapid life cycle allows researchers to observe and study multiple generations
within a short period of time.
 Due to its genetic tractability, short life cycle, and wealth of available genetic tools and
resources, Drosophila melanogaster has played a crucial role in advancing our
understanding of genetics, development, behavior, and disease mechanisms.
 Its contributions have extended beyond the field of biology and have impacted other
disciplines, including neuroscience, evolutionary biology,and biomedicine.

3.  Thomas Hunt Morgan (1866-1945)developedDrosophila as a model
system in 1909. Morgan, along with his students, Calvin Bridges,Alfred
Sturtevant, and Hermann Muller, made some of the most important
discoveriesin genetics through their work with Drosophila.
 Among these were the –
 Genetic explanation of sex linkage (the location. of a gene on a sex
chromosome);
 Proof that genes are contained on chromosomes;
 The demonstrationthat genes are arranged on a chromosome in a
linear order with fixed, measurabledistances between them, the
principle that underlies genetic mapping.

4. Life Cycle:-
 The Drosophila life cycle represents the
differentiation of two distinct forms: the larva and the
Imago (adult). Embryogenesis:
differentiation of
the larva
Imaginal cells
are the cells of
the adult or
image
Metamorphosis:
differentiation of
the image (adult)

5. THE DROSOPHILA GENOME:-
 Drosophila has four pairs of chromosomes
 x/y sex Chromosomes.
 autosomes:-
 2 and 3 - large metacentric chromosome.
 4 - very small telocentric chromosome.
 The size of genome is about 165 million bases and
contains estimated 14,000 genes. Thus development
can be define as the formation of different types of
tissues, organs, cells.

6. GENETIC MARKERS:-
 Cy¹ := Curly; The wings curve away from the body.
 e¹: ebony; Black body and wings.
 Sb¹: stubble; Bristles are shorter and thicker.
 w¹: white; Eyes lack pigmentation and appear white.
 y¹: =yellow; Body pigmentation and wings appear
yellow.

7. Drosophila as a model organism:-
 Simple Genome:- It consists of four pairs of chromosomes,with a total of around
13,000 protein-codinggenes. The genome contains a high degree of conservationwith
other organisms, includinghumans, makingit a valuabletool for studyinggene
function and evolutionary biology.
 Genetic Tools: Drosophila has a long history of genetic research, and numerous
genetic tools have been developed to manipulateits genome. These tools include
techniques like P-element transgenesis, GAL4/UASsystem, RNA interference
(RNAi), and CRISPR-Cas9 genome editing,allowingprecise control and manipulation
of gene expression.
 Well-studiedDevelopment:- The embryonic development of Drosophila is dividedinto
a series of definedstages, and the fate of individualcells duringdevelopment has
been extensively studied. This makes it an excellent model for studying
developmentalprocesses and the genetic control of development.
 Behavior and Neurobiology: Drosophila exhibits complexbehaviors and has a
relativelysimplenervous system, makingit an ideal modelfor studying the genetic
basis of behavior and neurobiology. Drosophilahas been used to investigatelearning
and memory,circadianrhythms, sensory processing, and manyother aspects of
neural function.

8. Genetic manipulation:-
 Classical Genetics:- Classical genetic techniques involve
the use of mating schemes to study the inheritance patterns
of traits. By crossing flies with known genetic mutations and
analyzing the phenotypes of the offspring, researchers can
identify genes involved in specific traits or biological
processes.

9.  Mutagenesis:- Mutagenesis techniques, such as
chemical mutagenesis or transposon-mediated
mutagenesis, can introduce random mutations into
the fly genome. These mutations can help identify
genes associated with specific phenotypes or
biological functions.

10.  Transgenesis:- Transgenesis involves introducing
foreign DNA sequences into the fly genome. This is
typically done using DNA injection techniques, where
exogenous DNA is injected into fly embryos.
Transgenic flies can express foreign genes or
modified versions of endogenous genes, allowing
researchers to study gene function and regulation.

11.  P-element Transgenesis:- P-
elements are a type of
transposable element that
naturally occurs in Drosophila.
P-element transgenesis
involves the use of P-elements
as vectors to introduce
exogenous DNA sequences into
the fly genome. P-element
vectors containing a gene of
interest can be injected into fly
embryos, and the P-element
transposase enzyme mediates
the insertion of the DNA into
random genomic locations. This
technique has been
instrumental in generating
transgenic flies that express
foreign genes or modified
versions of endogenous genes.