Editing Drosophila (section)

=== 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.<ref name="Pan">{{cite journal | vauthors = Pan Y, Robinett CC, Baker BS | title = Turning males on: activation of male courtship behavior in Drosophila melanogaster | journal = PLOS ONE | volume = 6 | issue = 6 | pages = e21144 | year = 2011 | pmid = 21731661 | pmc = 3120818 | doi = 10.1371/journal.pone.0021144 | doi-access = free | bibcode = 2011PLoSO...621144P }}</ref> Females respond via their perception of the behavior portrayed by the male.<ref name="Cook">{{cite journal | vauthors = Cook RM | title = Courtship processing in Drosophila melanogaster. II. An adaptation to selection for receptivity to wingless males | journal = Animal Behaviour | volume = 21 | issue = 2 | pages = 349–358 | date = May 1973 | pmid = 4198506 | doi = 10.1016/S0003-3472(73)80077-6 }}</ref> Male and female ''Drosophila'' use a variety of sensory cues to initiate and assess courtship readiness of a potential mate.<ref name="Pan" /><ref name="Cook" /><ref name="Crossly">{{cite journal | vauthors = Crossley SA, Bennet-Clark HC, Evert HT |year=1995 |title=Courtship song components affect male and female ''Drosophila'' differently |journal=Animal Behaviour |volume=50 |issue=3 |pages=827–839 |doi=10.1016/0003-3472(95)80142-1|s2cid=53161217 }}</ref> 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.<ref name="Ejimal and Griffith">{{cite journal | vauthors = Ejima A, Griffith LC | title = Measurement of Courtship Behavior in Drosophila melanogaster | journal = Cold Spring Harbor Protocols | volume = 2007 | issue = 10 | pages = pdb.prot4847 | date = October 2007 | pmid = 21356948 | doi = 10.1101/pdb.prot4847 }}</ref><ref name="Pan" /><ref name="Cook" /><ref name="Crossly" /> The songs of ''Drosophila melanogaster'' and ''Drosophila simulans'' have been studied extensively. These luring songs are sinusoidal in nature and varies within and between species.<ref name="Crossly" />

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.<ref name="Pan" /> Recent experiments explore the role of fruitless (''fru'') and doublesex (''dsx''), a group of sex-behaviour linked genes.<ref name="Certel">{{cite journal | vauthors = Certel SJ, Savella MG, Schlegel DC, Kravitz EA | title = Modulation of Drosophila male behavioral choice | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 104 | issue = 11 | pages = 4706–4711 | date = March 2007 | pmid = 17360588 | pmc = 1810337 | doi = 10.1073/pnas.0700328104 | doi-access = free | bibcode = 2007PNAS..104.4706C }}</ref><ref name="Pan" />

The [[Fruitless (gene)|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.<ref>{{cite journal | vauthors = Demir E, Dickson BJ | title = fruitless splicing specifies male courtship behavior in Drosophila | journal = Cell | volume = 121 | issue = 5 | pages = 785–794 | date = June 2005 | pmid = 15935764 | doi = 10.1016/j.cell.2005.04.027 | doi-access = free }}</ref> Male ''Drosophila'' with the ''fru'' mutation direct their courtship towards other males as opposed to typical courtship, which would be directed towards females.<ref name=":0">{{cite journal | vauthors = Yamamoto D, Kohatsu S | title = What does the fruitless gene tell us about nature vs. nurture in the sex life of Drosophila? | journal = Fly | volume = 11 | issue = 2 | pages = 139–147 | date = April 2017 | pmid = 27880074 | pmc = 5406164 | doi = 10.1080/19336934.2016.1263778 }}</ref> Loss of the ''fru'' mutation leads back to the typical courtship behavior.<ref name=":0" />

====Pheromones====
A novel class of [[pheromone]]s was found to be conserved across the subgenus ''Drosophila'' in 11 desert dwelling species.<ref name="pmid24618898">{{cite journal | vauthors = Chin JS, Ellis SR, Pham HT, Blanksby SJ, Mori K, Koh QL, Etges WJ, Yew JY | display-authors = 6 | title = Sex-specific triacylglycerides are widely conserved in Drosophila and mediate mating behavior | journal = eLife | volume = 3 | issue =  | pages = e01751 | date = March 2014 | pmid = 24618898 | pmc = 3948109 | doi = 10.7554/eLife.01751 | doi-access = free }}</ref>  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 melanogaster]]'', and ''[[Drosophila neotestacea]]''. [[Polyandry in animals|Polyandry]] is a prominent mating system among ''Drosophila''.<ref name=" Frentiu and Chenoweth">{{cite journal | vauthors = Frentiu FD, Chenoweth SF | title = Polyandry and paternity skew in natural and experimental populations of Drosophila serrata | journal = Molecular Ecology | volume = 17 | issue = 6 | pages = 1589–1596 | date = March 2008 | pmid = 18266626 | doi = 10.1111/j.1365-294X.2008.03693.x | bibcode = 2008MolEc..17.1589F | s2cid = 23286566 }}</ref><ref name=" Puurtinen and Fromhage ">{{cite journal | vauthors = Puurtinen M, Fromhage L | title = Evolution of male and female choice in polyandrous systems | journal = Proceedings. Biological Sciences | volume = 284 | issue = 1851 | page = 20162174 | date = March 2017 | pmid = 28330914 | pmc = 5378073 | doi = 10.1098/rspb.2016.2174 }}</ref><ref name=" Herrera et al. ">{{cite journal | vauthors = Herrera P, Taylor ML, Skeats A, Price TA, Wedell N | title = Can patterns of chromosome inversions in Drosophila pseudoobscura predict polyandry across a geographical cline? | journal = Ecology and Evolution | volume = 4 | issue = 15 | pages = 3072–3081 | date = August 2014 | pmid = 25247064 | pmc = 4161180 | doi = 10.1002/ece3.1165 | bibcode = 2014EcoEv...4.3072H }}</ref><ref name=" Pinzone and Dyer.">{{cite journal | vauthors = Pinzone CA, Dyer KA | title = Association of polyandry and sex-ratio drive prevalence in natural populations of Drosophila neotestacea | journal = Proceedings. Biological Sciences | volume = 280 | issue = 1769 | pages = 20131397 | date = October 2013 | pmid = 24004936 | pmc = 3768301 | doi = 10.1098/rspb.2013.1397 }}</ref> Females mating with multiple sex partners has been a beneficial mating strategy for ''Drosophila''.<ref name=" Frentiu and Chenoweth " /><ref name=" Puurtinen and Fromhage " /><ref name=" Herrera et al." /><ref name=" Pinzone and Dyer." /> The benefits include both pre and post copulatory mating. Pre-copulatory strategies are the behaviours associated with [[mate choice]] and the genetic contributions, such as production of gametes, that are exhibited by both male and female ''Drosophila'' regarding mate choice.<ref name=" Frentiu and Chenoweth " /><ref name=" Puurtinen and Fromhage " /> Post copulatory strategies include sperm competition, mating frequency, and sex-ratio meiotic drive.<ref name=" Frentiu and Chenoweth " /><ref name=" Puurtinen and Fromhage " /><ref name=" Herrera et al." /><ref name=" Pinzone and Dyer." />

These lists are not inclusive. Polyandry among the ''Drosophila pseudoobscura'' in North America vary in their number of mating partners.<ref name=" Herrera et al." />  There is a connection between the number of time females choose to mate and chromosomal variants of the third chromosome.<ref name=" Herrera et al." /> It is believed that the presence of the inverted [[Chromosomal polymorphism|polymorphism]] is why re-mating by females occurs.<ref name=" Herrera et al." /> The stability of these polymorphisms may be related to the sex-ratio meiotic drive.<ref name=" Pinzone and Dyer."/>

However, for ''[[Drosophila subobscura]],'' the main mating system is monandry, not normally seen in ''Drosophila.''<ref>{{cite journal | vauthors = Holman L, Freckleton RP, Snook RR | title = What use is an infertile sperm? A comparative study of sperm-heteromorphic Drosophila | journal = Evolution; International Journal of Organic Evolution | volume = 62 | issue = 2 | pages = 374–385 | date = February 2008 | pmid = 18053077 | doi = 10.1111/j.1558-5646.2007.00280.x | s2cid = 12804737 | doi-access = free }}</ref>

====Sperm competition====
The following section is based on the following ''Drosophila'' species: ''Drosophila melanogaster'', ''Drosophila simulans'', and ''Drosophila mauritiana''. [[Sperm competition]] is a process that polyandrous ''Drosophila'' females use to increase the fitness of their offspring.<ref name="Manier et al">{{cite journal | vauthors = Manier MK, Belote JM, Berben KS, Lüpold S, Ala-Honkola O, Collins WF, Pitnick S | title = Rapid diversification of sperm precedence traits and processes among three sibling Drosophila species | journal = Evolution; International Journal of Organic Evolution | volume = 67 | issue = 8 | pages = 2348–2362 | date = August 2013 | pmid = 23888856 | doi = 10.1111/evo.12117 | s2cid = 24845539 | doi-access = free }}</ref><ref name="Clark, Begun and Prout">{{cite journal | vauthors = Clark AG, Begun DJ, Prout T | title = Female x male interactions in Drosophila sperm competition | journal = Science | volume = 283 | issue = 5399 | pages = 217–220 | date = January 1999 | pmid = 9880253 | doi = 10.1126/science.283.5399.217 | s2cid = 43031475 | jstor = 2897403 }}</ref><ref name="Mack et al">{{cite journal | vauthors = Mack PD, Hammock BA, Promislow DE | title = Sperm competitive ability and genetic relatedness in Drosophila melanogaster: similarity breeds contempt | journal = Evolution; International Journal of Organic Evolution | volume = 56 | issue = 9 | pages = 1789–1795 | date = September 2002 | pmid = 12389723 | doi = 10.1111/j.0014-3820.2002.tb00192.x | s2cid = 2140754 | doi-access = free }}</ref><ref name=" Manier et al. 2013">{{cite journal | vauthors = Manier MK, Lüpold S, Pitnick S, Starmer WT | title = An analytical framework for estimating fertilization bias and the fertilization set from multiple sperm-storage organs | journal = The American Naturalist | volume = 182 | issue = 4 | pages = 552–561 | date = October 2013 | pmid = 24021407 | doi = 10.1086/671782 | bibcode = 2013ANat..182..552M | s2cid = 10040656 | url = https://www.zora.uzh.ch/id/eprint/113525/1/Manier%20etal%20AmNat%202013.pdf | author-link4 = William T. Starmer }}</ref><ref name="Ala-Honkola and Manier">{{cite journal | vauthors = Ala-Honkola O, Manier MK |year=2016 |title=Multiple mechanisms of cryptic female choice act on intraspecific male variation in ''Drosophila simulans'' |journal=Behavioral Ecology and Sociobiology |volume=70 |issue=4 |pages=519–532 |doi=10.1007/s00265-016-2069-3 |bibcode=2016BEcoS..70..519A |s2cid=17465840 |url=http://urn.fi/URN:NBN:fi:jyu-201603211902 }}</ref> 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.<ref name="Ala-Honkola and Manier"/> However, some species of ''Drosophila'' have evolved to only use one or the other.<ref>{{cite journal | vauthors = Pitnick S, Marrow T, Spicer GS | title = Evolution of Multiple Kinds of Female Sperm-Storage Organs in Drosophila | journal = Evolution; International Journal of Organic Evolution | volume = 53 | issue = 6 | pages = 1804–1822 | date = December 1999 | pmid = 28565462 | doi = 10.2307/2640442 | jstor = 2640442 }}</ref> Females have little control when it comes to [[cryptic female choice]].<ref name=" Manier et al. 2013"/><ref name="Clark, Begun and Prout"/> Female ''Drosophila'' through cryptic choice, one of several post-copulatory mechanisms, which allows for the detection and expelling of sperm that reduces inbreeding possibilities.<ref name="Mack et al"/><ref name="Clark, Begun and Prout"/> 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.<ref name="Manier et al. 2013"/> Among the preceding species there are variations at each stage that play a role in the natural selection process.<ref name="Manier et al. 2013"/> This sperm competition has been found to be a driving force in the establishment of reproductive isolation during speciation.<ref>{{cite journal | vauthors = Lüpold S, Manier MK, Puniamoorthy N, Schoff C, Starmer WT, Luepold SH, Belote JM, Pitnick S | display-authors = 6 | title = How sexual selection can drive the evolution of costly sperm ornamentation | journal = Nature | volume = 533 | issue = 7604 | pages = 535–538 | date = May 2016 | pmid = 27225128 | doi = 10.1038/nature18005 | s2cid = 4407752 | bibcode = 2016Natur.533..535L | url = https://zenodo.org/record/1000843 }}</ref><ref>{{cite journal | vauthors = Zajitschek S, Zajitschek F, Josway S, Al Shabeeb R, Weiner H, Manier MK | title = Costs and benefits of giant sperm and sperm storage organs in Drosophila melanogaster | journal = Journal of Evolutionary Biology | volume = 32 | issue = 11 | pages = 1300–1309 | date = November 2019 | pmid = 31465604 | doi = 10.1111/jeb.13529 | s2cid = 191162620 | biorxiv = 10.1101/652248 | doi-access = free }}</ref>

==== Parthenogenesis and gynogenesis ====
[[Parthenogenesis]] 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''.<ref>{{Cite journal |last=Markow |first=Therese Ann |date=2013-04-01 |title=Parents Without Partners: Drosophila as a Model for Understanding the Mechanisms and Evolution of Parthenogenesis |journal=G3: Genes, Genomes, Genetics |language=en |volume=3 |issue=4 |pages=757–762 |doi=10.1534/g3.112.005421 |issn=2160-1836 |pmc=3618362 |pmid=23550124}}</ref><ref>{{Cite journal |last1=Loppin |first1=Benjamin |last2=Dubruille |first2=Raphaëlle |last3=Horard |first3=Béatrice |date=August 2015 |title=The intimate genetics of Drosophila fertilization |journal=Open Biology |language=en |volume=5 |issue=8 |pages=150076 |doi=10.1098/rsob.150076 |issn=2046-2441 |pmc=4554920 |pmid=26246493}}</ref>