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''Drosophila'' (), from
Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of fly, belonging to the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Drosophilidae The Drosophilidae are a diverse, cosmopolitan family of flies, which includes species called fruit flies, although they are more accurately referred to as vinegar or pomace flies. Another distantly related family of flies, Tephritidae, are true f ...
, whose members are often called "small fruit flies" or pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit. They should not be confused with the
Tephritidae The Tephritidae are one of two fly families referred to as fruit flies, the other family being the Drosophilidae. The family Tephritidae does not include the biological model organisms of the genus '' Drosophila'' (in the family Drosophilidae ...
, a related family, which are also called fruit flies (sometimes referred to as "true fruit flies"); tephritids feed primarily on unripe or ripe
fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...
, with many species being regarded as destructive agricultural pests, especially the Mediterranean fruit fly. One species of ''Drosophila'' in particular, ''
Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...
'', has been heavily used in research in
genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...
and is a common
model organism A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...
in
developmental biology Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of Regeneration (biology), regeneration, asexual reproduction, metamorphosis, and the growth and di ...
. The terms "fruit fly" and "''Drosophila''" are often used synonymously with ''D. melanogaster'' in modern biological literature. The entire genus, however, contains more than 1,500 species and is very diverse in appearance, behavior, and breeding habitat.


Etymology

The term "''Drosophila''", meaning "dew-loving", is a modern scientific
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
adaptation from
Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...
words , ', "
dew Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening due to condensation. As the exposed surface cools by thermal radiation, radiating its heat, atmospheric moisture condenses at a rate grea ...
", and , ', "loving".


Morphology

''Drosophila'' species are small flies, typically pale yellow to reddish brown to black, with red eyes. When the eyes (essentially a film of lenses) are removed, the brain is revealed. ''Drosophila'' brain structure and function develop and age significantly from
larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
l to adult stage. Developing brain structures make these flies a prime candidate for neuro-genetic research. According to a study published in
Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...
in October 2024, by the scientists examining the brain of an adult female Drosophila, the shape and location of each of its 130,000
neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...
s and 50 million
synapsis Synapsis or Syzygy is the pairing of two chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of me ...
were identified. In this study, the most detailed analysis ever conducted on the brain of an adult animal is represented. Many species, including the noted Hawaiian picture-wings, have distinct black patterns on the wings. The plumose (feathery) arista, bristling of the head and thorax, and wing venation are characters used to diagnose the family. Most are small, about long, but some, especially many of the Hawaiian species, are larger than a
house fly The housefly (''Musca domestica'') is a fly of the suborder Cyclorrhapha. It possibly originated in the Middle East, and spread around the world as a commensal of humans. Adults are gray to black, with four dark, longitudinal lines on the t ...
.


Evolution


Detoxification mechanisms

Environmental challenge by natural toxins helped to prepare ''Drosophila''e to detox DDT, by shaping the glutathione ''S''-transferase mechanism that metabolizes both.


Selection

The ''Drosophila'' genome is subject to a high degree of selection, especially unusually widespread negative selection compared to other
taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...
. A majority of the genome is under selection of some sort, and a supermajority of this is occurring in
non-coding DNA Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules (e.g. transfer RNA, microRNA, piRNA, ribosomal RNA, and reg ...
.
Effective population size The effective population size (''N'e'') is the size of an idealised population that would experience the same rate of genetic drift as the real population. Idealised populations are those following simple one- locus models that comply with ass ...
has been credibly suggested to positively correlate with the effect size of both negative and positive selection. Recombination is likely to be a significant source of
diversity Diversity, diversify, or diverse may refer to: Business *Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce *Diversity marketing, marketing communication targeting diverse customers * ...
. There is evidence that crossover is positively correlated with polymorphism in ''D.'' populations.


Biology


Habitat

''Drosophila'' species are found all around the world, with more species in the tropical regions. ''Drosophila'' made their way to the Hawaiian Islands and radiated into over 800 species. They can be found in
deserts A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the l ...
,
tropical rainforest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zo ...
,
cities A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agree ...
,
swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...
s, and alpine zones. Some northern species hibernate. The northern species '' D. montana'' is the best cold-adapted, and is primarily found at high altitudes. Most species breed in various kinds of decaying plant and
fungal A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the tradit ...
material, including
fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...
,
bark Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...
, slime fluxes,
flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...
s, and
mushroom A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the n ...
s. ''Drosophila'' species that are fruit-breeding are attracted to various products of fermentation, especially
ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...
and
methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...
. Fruits exploited by ''Drosophila'' species include those with a high pectin concentration, which is an indicator of how much alcohol will be produced during fermentation. Citrus, morinda, apples, pears, plums, and apricots belong into this category. The larvae of at least one species, '' D. suzukii'', can also feed in fresh fruit and can sometimes be a pest. A few species have switched to being
parasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...
or
predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
s. Many species can be attracted to baits of fermented
banana A banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large treelike herbaceous flowering plants in the genus '' Musa''. In some countries, cooking bananas are called plantains, distinguishing the ...
s or mushrooms, but others are not attracted to any kind of baits. Males may congregate at patches of suitable breeding substrate to compete for the females, or form leks, conducting courtship in an area separate from breeding sites. Several ''Drosophila'' species, including ''Drosophila melanogaster'', '' D. immigrans'', and '' D. simulans'', are closely associated with humans, and are often referred to as
domestic Domestic may refer to: In the home * Anything relating to the human home or family ** A domestic animal, one that has undergone domestication ** A domestic appliance, or home appliance ** A domestic partnership ** Domestic science, sometimes cal ...
species. These and other species ('' D. subobscura'', and from a related genus '' Zaprionus indianus'') have been accidentally introduced around the world by human activities such as fruit transports.


Reproduction

Males of this genus are known to have the longest sperm cells of any studied organism on Earth, including one species, '' Drosophila bifurca'', that has sperm cells that are long. The cells mostly consist of a long, thread-like tail, and are delivered to the females in tangled coils. The other members of the genus ''Drosophila'' also make relatively few giant sperm cells, with that of ''D. bifurca'' being the longest. ''D. melanogaster'' sperm cells are a more modest 1.8 mm long, although this is still about 35 times longer than a human sperm. Several species in the ''D. melanogaster'' species group are known to mate by traumatic insemination. ''Drosophila'' species vary widely in their reproductive capacity. Those such as ''D. melanogaster'' that breed in large, relatively rare resources have
ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...
that mature 10–20 eggs at a time, so that they can be laid together on one site. Others that breed in more-abundant but less nutritious substrates, such as leaves, may only lay one egg per day. The eggs have one or more respiratory filaments near the anterior end; the tips of these extend above the surface and allow oxygen to reach the embryo. Larvae feed not on the vegetable matter itself, but on the
yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...
s and
microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...
s present on the decaying breeding substrate. Development time varies widely between species (between 7 and more than 60 days) and depends on the environmental factors such as
temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...
, breeding substrate, and crowding. Fruit flies lay eggs in response to environmental cycles. Eggs laid at a time (e.g., night) during which likelihood of survival is greater than in eggs laid at other times (e.g., day) yield more larvae than eggs that were laid at those times. ''Ceteris paribus'', the habit of laying eggs at this 'advantageous' time would yield more surviving offspring, and more grandchildren, than the habit of laying eggs during other times. This differential reproductive success would cause ''D. melanogaster'' to adapt to environmental cycles, because this behavior has a major reproductive advantage. Their median lifespan is 35–45 days.


Aging

DNA damage accumulates in ''Drosophila'' intestinal
stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...
s with age. Deficiencies in the ''Drosophila'' DNA damage response, including deficiencies in expression of genes involved in DNA damage repair, accelerates intestinal stem cell (
enterocyte Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase ...
) aging. Sharpless and Depinho reviewed evidence that stem cells undergo intrinsic aging and speculated that stem cells grow old, in part, as a result of DNA damage.


Mating systems


Courtship behavior

The following section is based on the following ''Drosophila'' species: ''Drosophila simulans'' and ''Drosophila melanogaster''. Courtship behavior of male ''Drosophila'' is an attractive behaviour. Females respond via their perception of the behavior portrayed by the male. Male and female ''Drosophila'' use a variety of sensory cues to initiate and assess courtship readiness of a potential mate. The cues include the following behaviours: positioning, pheromone secretion, following females, making tapping sounds with legs, singing, wing spreading, creating wing vibrations, genitalia licking, bending the stomach, attempt to copulate, and the copulatory act itself. The songs of ''Drosophila melanogaster'' and ''Drosophila simulans'' have been studied extensively. These luring songs are sinusoidal in nature and vary within and between species. The courtship behavior of ''Drosophila melanogaster'' has also been assessed for sex-related genes, which have been implicated in courtship behavior in both the male and female. Recent experiments explore the role of fruitless (''fru'') and doublesex (''dsx''), a group of sex-behaviour linked genes. The fruitless (''fru'') gene in ''Drosophila'' helps regulate the network for male courtship behavior; when a mutation to this gene occurs altered same sex sexual behavior in males is observed. Male ''Drosophila'' with the ''fru'' mutation direct their courtship towards other males as opposed to typical courtship, which would be directed towards females. Loss of the ''fru'' mutation leads back to the typical courtship behavior.


Pheromones

A novel class of
pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
s was found to be conserved across the subgenus ''Drosophila'' in 11 desert dwelling species. These pheromones are triacylglycerides that are secreted exclusively by males from their ejaculatory bulb and transferred to females during mating. The function of the pheromones is to make the females unattractive to subsequent suitors and thus inhibit courtship by other males.


Polyandry

The following section is based on the following ''Drosophila'' species: '' Drosophila serrata'', ''
Drosophila pseudoobscura ''Drosophila pseudoobscura'' is a species of Drosophilidae, fruit fly, used extensively in lab studies of speciation. It is native to western North America. In 2005, ''D. pseudoobscura'' was the second ''Drosophila'' species to have its genome ...
'', ''
Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...
'', and '' Drosophila neotestacea''.
Polyandry Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives ...
is a prominent mating system among ''Drosophila''. Females mating with multiple sex partners has been a beneficial mating strategy for ''Drosophila''. The benefits include both pre and post copulatory mating. Pre-copulatory strategies are the behaviours associated with
mate choice Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choi ...
and the genetic contributions, such as production of gametes, that are exhibited by both male and female ''Drosophila'' regarding mate choice. Post copulatory strategies include sperm competition, mating frequency, and sex-ratio meiotic drive. These lists are not inclusive. Polyandry among the ''Drosophila pseudoobscura'' in North America vary in their number of mating partners. There is a connection between the number of time females choose to mate and chromosomal variants of the third chromosome. It is believed that the presence of the inverted polymorphism is why re-mating by females occurs. The stability of these polymorphisms may be related to the sex-ratio meiotic drive. However, for '' Drosophila subobscura,'' the main mating system is monandry, not normally seen in ''Drosophila.''


Sperm competition

The following section is based on the following ''Drosophila'' species: ''Drosophila melanogaster'', ''Drosophila simulans'', and ''Drosophila mauritiana''.
Sperm competition Sperm competition is the competitive process between Spermatozoon, spermatozoa of two or more different males to fertility, fertilize the same Egg cell, egg during sexual reproduction. Competition can occur when females have multiple potential m ...
is a process that polyandrous ''Drosophila'' females use to increase the fitness of their offspring. The female ''Drosophila'' has two sperm storage organs, the spermathecae and seminal receptacle, that allows her to choose the sperm that will be used to inseminate her eggs. However, some species of ''Drosophila'' have evolved to only use one or the other. Females have little control when it comes to
cryptic female choice Cryptic female choice is a form of mate choice which occurs both in pre- and post-copulatory circumstances in which females of certain species use physical or chemical mechanisms to control a male's success of fertilizing their ova or ovum; i.e. by ...
. Female ''Drosophila'' through cryptic choice, one of several post-copulatory mechanisms, which allows for the detection and expelling of sperm that reduces inbreeding possibilities. Manier et al. 2013 has categorized the post copulatory sexual selection of ''Drosophila melanogaster'', ''Drosophila simulans'', and ''Drosophila mauritiana'' into the following three stages: insemination, sperm storage, and fertilizable sperm. Among the preceding species there are variations at each stage that play a role in the natural selection process. This sperm competition has been found to be a driving force in the establishment of reproductive isolation during speciation.


Parthenogenesis and gynogenesis

Parthenogenesis Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertiliz ...
does not occur in ''D. melanogaster'', but in the ''gyn-f9'' mutant, gynogenesis occurs at low frequency. The natural populations of ''D. mangebeirai'' are entirely female, making it the only obligate parthenogenetic species of Drosophila. Parthenogenesis is facultative in ''parthenogenetica'' and ''mercatorum''.


Laboratory-cultured animals

'' D. melanogaster'' is a popular experimental animal because it is easily cultured en masse out of the wild, has a short generation time, and mutant animals are readily obtainable. In 1906,
Thomas Hunt Morgan Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) was an Americans, American evolutionary biologist, geneticist, Embryology, embryologist, and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries e ...
began his work on ''D. melanogaster'' and reported his first finding of a white eyed mutant in 1910 to the academic community. He was in search of a model organism to study genetic heredity and required a species that could randomly acquire genetic mutation that would visibly manifest as morphological changes in the adult animal. His work on ''Drosophila'' earned him the 1933
Nobel Prize The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred N ...
in Medicine for identifying
chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...
s as the vector of inheritance for genes. This and other ''Drosophila'' species are widely used in studies of
genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...
,
embryogenesis An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male ...
, chronobiology,
speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...
,
neurobiology Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...
, and other areas. However, some species of ''Drosophila'' are difficult to culture in the laboratory, often because they breed on a single specific host in the wild. For some, it can be done with particular recipes for rearing media, or by introducing chemicals such as
sterols A sterol is any organic compound with a Skeletal formula, skeleton closely related to Cholestanol, cholestan-3-ol. The simplest sterol is gonan-3-ol, which has a formula of , and is derived from that of gonane by replacement of a hydrogen atom on ...
that are found in the natural host; for others, it is (so far) impossible. In some cases, the larvae can develop on normal ''Drosophila'' lab medium, but the female will not lay eggs; for these it is often simply a matter of putting in a small piece of the natural host to receive the eggs. The Drosophila Species Stock Center located at
Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...
in Ithaca, New York, maintains cultures of hundreds of species for researchers.


Use in genetic research

''Drosophila'' is considered one of the most valuable genetic model organisms; both adults and embryos are used in experiments. . . . ''Drosophila'' is a prime candidate for genetic research because the relationship between human and fruit fly genes is very close; disease-producing genes in humans can be linked to those in ''Drosophila''. The fly has approximately 15,500 genes on its four chromosomes, whereas humans have about 22,000 genes among their 23 chromosomes. The low number of chromosomes make ''Drosophila'' easier to study. Genetic traits can be studied through different ''Drosophila'' lineages, and the findings can be applied to deduce genetic trends in humans. Research conducted on ''Drosophila'' has helped to determine the ground rules for genetic inheritance in many organisms. ''Drosophila'' is a useful in vivo tool to analyze Alzheimer's disease.
Rhomboid protease The rhomboid proteases are a family of enzymes that exist in almost all species. They are proteases: they cut the polypeptide chain of other proteins. This proteolytic cleavage is irreversible in cell (biology), cells, and an important type of cel ...
s were first detected in ''Drosophila'' but then found to be highly conserved across
eukaryote The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...
s,
mitochondria A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is us ...
, and
bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
. Melanin's ability to protect DNA against
ionizing radiation Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching ...
has been most extensively demonstrated in ''Drosophila'', including in the formative study by Hopwood et al. in 1985.


Microbiome

Like other animals, ''Drosophila'' is associated with various bacteria in its gut. The fly gut microbiota or microbiome seems to have a central influence on ''Drosophila'' fitness and life history characteristics. The microbiota in the gut of ''Drosophila'' represents an active current research field. ''Drosophila'' species also harbour vertically transmitted endosymbionts, such as ''
Wolbachia ''Wolbachia'' is a genus of gram-negative bacteria infecting many species of arthropods and filarial nematodes. The symbiotic relationship ranges from parasitism to obligate mutualism. It is one of the most common parasitic microbes of arthrop ...
'' and '' Spiroplasma''. These endosymbionts can act as reproductive manipulators, such as cytoplasmic incompatibility induced by ''Wolbachia'' or male-killing induced by the ''D. melanogaster Spiroplasma poulsonii'' (named MSRO). The male-killing factor of the ''D. melanogaster'' MSRO strain was discovered in 2018, solving a decades-old mystery of the cause of male-killing. This represents the first bacterial factor that affects eukaryotic cells in a sex-specific fashion, and is the first mechanism identified for male-killing phenotypes. Alternatively, they may protect theirs hosts from infection. ''Drosophila Wolbachia'' can reduce viral loads upon infection, and is explored as a mechanism of controlling viral diseases (''e.g.'' Dengue fever) by transferring these ''Wolbachia'' to disease-vector mosquitoes. The ''S. poulsonii'' strain of '' Drosophila neotestacea'' protects its host from parasitic wasps and nematodes using toxins that preferentially attack the parasites instead of the host. Since the ''Drosophila'' species is one of the most used model organisms, it was vastly used in genetics. However, the effect abiotic factors, such as temperature, has on the
microbiome A microbiome () is the community of microorganisms that can usually be found living together in any given habitat. It was defined more precisely in 1988 by Whipps ''et al.'' as "a characteristic microbial community occupying a reasonably wel ...
on Drosophila species has recently been of great interest. Certain variations in temperature have an impact on the microbiome. It was observed that higher temperatures (31 °C) lead to an increase of ''Acetobacter'' populations in the Gut microbiota, gut microbiome of ''
Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...
'' as compared to lower temperatures (13 °C). In low temperatures (13 °C), the flies were more cold resistant and also had the highest concentration of ''Wolbachia.'' The microbiome in the gut can also be transplanted among organisms. It was found that ''Drosophila melanogaster'' became more cold-tolerant when the gut microbiota from ''Drosophila melanogaster'' that were reared at low temperatures. This depicted that the gut microbiome is correlated to physiological processes. Moreover, the microbiome plays a role in aggression, immunity, egg-laying preferences, locomotion and metabolism. As for aggression, it plays a role to a certain degree during courtship. It was observed that germ-free flies were not as competitive compared to the wild-type males. Microbiome of the ''Drosophila'' species is also known to promote aggression by octopamine OA signalling. The microbiome has been shown to impact these fruit flies' social interactions, specifically aggressive behaviour that is seen during Courtship display, courtship and mating.


Predators

''Drosophila'' species are prey for many generalist predators, such as Asilidae, robber flies. In Hawaii, the introduction of Vespula, yellowjackets from mainland United States has led to the decline of many of the larger species. The larvae are preyed on by other fly larvae, Staphylinidae, staphylinid beetles, and ants.


Neurochemistry

Fruit flies use several fast-acting neurotransmitters, similar to those found in humans, which allow neurons to communicate and coordinate behavior. Acetylcholine, glutamate, gamma-aminobutyric acid (GABA), dopamine, serotonin, and histamine are all neurotransmitters that can be found in humans, but Drosophila also have another neurotransmitter, octopamine, the analog of norepinephrine. Acetylcholine is the primary excitatory neurotransmitter and GABA is the primary inhibitory neurotransmitter utilized in the drosophila central nervous system. In Drosophila, the effects of many neurotransmitters can vary depending on the receptors and signaling pathways involved, allowing them to act as excitatory or inhibitory signals under different contexts. This versatility enables complex neural processing and behavioral flexibility. Glutamate can serve as an excitatory neurotransmitter, specifically at the neuromuscular junction in fruit flies. This differs from vertebrates, where acetylcholine is used at these junctions. In Drosophila, histamine primarily functions as a neurotransmitter in the visual system. It is released by photoreceptor cells to transmit visual information from the eye to the brain, making it essential for vision. As with many Eukaryotes, this genus is known to express SNARE (protein), SNAREs, and as with several others the components of the SNARE complex are known to be somewhat substitutable: Although the loss of SNAP-25 - a component of neuronal SNAREs - is lethal, SNAP-24 can fully replace it. For another example, an R-SNARE not normally found in synapses can substitute for synaptobrevin.


Immunity

The Spätzle (gene), Spätzle protein is a ligand of Toll signaling, Toll. In addition to melanin's more commonly known roles in the endoskeleton and in neurochemistry, melanization is one step in the immune responses to some pathogens. Dudzic et al. 2019 additionally find a large number of shared serine protease messengers between Spätzle/Toll and melanization and a large amount of crosstalk (biology), crosstalk between these pathways.


Systematics

The
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Drosophila'' as currently defined is paraphyletic (see below) and contains 1,450 described species, while the total number of species is estimated at thousands. The majority of the species are members of two subgenera: ''Drosophila'' (about 1,100 species) and ''Sophophora'' (including ''Drosophila melanogaster, D. (S.) melanogaster''; around 330 species). The Hawaiian species of ''Drosophila'' (estimated to be more than 500, with roughly 380 species described) are sometimes recognized as a separate genus or subgenus, ''Idiomyia'', but this is not widely accepted. About 250 species are part of the genus ''Scaptomyza'', which arose from the Hawaiian ''Drosophila'' and later recolonized continental areas. Evidence from phylogenetic studies suggests these genera arose from within the genus ''Drosophila'': *''Liodrosophila'' Duda, 1922 *''Mycodrosophila'' Oldenburg, 1914 *''Samoaia'' Malloch, 1934 *''Scaptomyza'' Hardy, 1849 *''Zaprionus'' Coquillett, 1901 *''Zygothrica'' Wiedemann, 1830 *''Hirtodrosophila'' Duda, 1923 (position uncertain) Several of the subgeneric and generic names are based on anagrams of ''Drosophila'', including ''Dorsilopha'', ''Lordiphosa'', ''Siphlodora'', ''Phloridosa'', and ''Psilodorha''.


Genetics

''Drosophila'' species are extensively used as model organisms in genetics (including population genetics), cell biology, biochemistry, and especially developmental biology. Therefore, extensive efforts are made to sequence drosophilid genomes. The genomes of these species have been fully sequenced: *''Drosophila melanogaster, Drosophila (Sophophora) melanogaster'' *''Drosophila simulans, Drosophila (Sophophora) simulans'' *''Drosophila sechellia, Drosophila (Sophophora) sechellia'' *''Drosophila yakuba, Drosophila (Sophophora) yakuba'' *''Drosophila erecta, Drosophila (Sophophora) erecta'' *''Drosophila ananassae, Drosophila (Sophophora) ananassae'' *''Drosophila pseudoobscura, Drosophila (Sophophora) pseudoobscura'' *''Drosophila persimilis, Drosophila (Sophophora) persimilis'' *''Drosophila willistoni, Drosophila (Sophophora) willistoni'' *''Drosophila mojavensis, Drosophila (Drosophila) mojavensis'' *''Drosophila virilis, Drosophila (Drosophila) virilis'' *''Drosophila grimshawi, Drosophila (Drosophila) grimshawi'' The data have been used for many purposes, including evolutionary genome comparisons. ''D. simulans'' and ''D. sechellia'' are sister species, and provide viable offspring when crossed, while ''D. melanogaster'' and ''D. simulans'' produce infertile Hybrid (biology), hybrid offspring. The ''Drosophila'' genome is often compared with the genomes of more distantly related species such as the honeybee ''Western honeybee, Apis mellifera'' or the mosquito ''Anopheles gambiae''. The ''Drosophila'' modEncode project conducted extensive work to annotate ''Drosophila'' genomes, profile transcripts, histone modifications, transcription factors, regulatory networks, and other aspects of ''Drosophila'' genetics, and make predictions about gene expression among others. FlyBase serves as a centralized database of curated genomic data on ''Drosophila.'' The has presented ten new genomes and combines those with previously released genomes for ''D. melanogaster'' and ''D. pseudoobscura'' to analyse the evolutionary history and common genomic structure of the genus. This includes the discovery of transposable elements (TEs) and illumination of their evolutionary history. Bartolomé et al. 2009 find at least of the TEs in ''D. melanogaster'', ''D. simulans'' and ''D. yakuba'' have been acquired by horizontal transfer. They find an average rate of 0.035 horizontal transfer events per TE family per million years. Bartolomé also finds horizontal transfer of TEs follows other relatedness metrics, with transfer events between ''D. melanogaster and'' ''D. simulans'' being twice as common as either of them with ''D. yakuba''.


See also

*Drosophila hybrid sterility *Laboratory experiments of speciation *List of Drosophila species, List of ''Drosophila'' species *''Caenorhabditis'' Drosophilae supergroup, 'Drosophilae' species supergroup, a group of species generally found on rotten fruits and transported by ''Drosophila'' flies


References


External links

* FlyBase is a comprehensive database for information on the genetics and molecular biology of ''Drosophila''. It includes data from the ''Drosophila'' Genome Projects and data curated from the literature. * is an integrated database of genomic, expression and protein data for ''Drosophila'' * University of California, Santa Cruz ** ** breeds hundreds of species and supplies them to researchers * Lawrence Berkeley National Laboratory ** ** * * * is library of ''Drosophila'' on the web * * – In India microinjection service for the generation of transgenic lines, Screening Platforms, ''Drosophila'' strain development {{Authority control Drosophila, Drosophilidae genera Taxa named by Carl Fredrik Fallén Animal models