fruitless (gene)
| fruitless | |||||||
|---|---|---|---|---|---|---|---|
| Identifiers | |||||||
| Organism | |||||||
| Symbol | fru | ||||||
| Entrez | 42226 | ||||||
| RefSeq (mRNA) | NM_169821.1 | ||||||
| RefSeq (Prot) | NP_732349.1 | ||||||
| UniProt | Q8IN81 | ||||||
| Other data | |||||||
| Chromosome | 3R: 14.22 - 14.39 Mb | ||||||
| |||||||
Thefruitlessgene(fru) is aDrosophila melanogastergenethat encodes several variants of a putativetranscription factorprotein.Normalfruitlessfunction is required for proper development of several anatomical structures necessary for courtship, includingmotor neuronswhich innervatemusclesneeded for fly sexual behaviors.[1]The gene does not have an obvious mammalian homolog, but appears to function in sex determination in species as distant as the mosquitoAnopheles gambiae.[2]
fruitlessserves as an example of how a gene or a group of genes may regulate the development and/or function of neurons involved in innate behavior. Research onfruitlesshas received attention in the popular press, since it provokes discussion ongenetics of human sexual orientation,[3][4]and behaviors such as gender-specificaggression.[5]
Function
[edit]Maleflies with mutations in thefruitlessgene display altered sexual behavior. Fruitfly courtship, which involves a complex male-initiatedritual,may be disrupted in many ways by mutatedfrualleles;fruis necessary for every step in the ritual. Some alleles prevent courting entirely, while others disrupt individual components. Notably, someloss-of-functionalleles change or removesexual preference.[1]
Although many genes are known to be involved in male courtship behavior, thefruitlessgene has been considered noteworthy because it exhibits sex-specificalternative splicing.When females produce the male-spliced gene product, they behave as males. Males that do not produce the male-specific product do not court females and are infertile.[1]In the brain, a subset (ca. 2,000) of neurons expressfruitless[6]andfruitlessexpression is sufficient to instruct sexually dimorphic connectivity.[7][8]
fruitlesshas at least fourpromoters,each encoding proteins containing both a BTB (Broad complex/tramtrack/bric-a-brac) domain and azinc fingermotif.Alternative splicing occurs at both the 5' and 3' ends, and there are several variants (other than the male- and female-specific splicing patterns).[1]The fruitless gene locus also controls the expression of hundreds of other genes,[9]any subset of which may actually regulate behavior.
Name
[edit]Early work refers to the gene asfruity,an apparent pun on both the common name ofD. melanogaster,thefruit fly,as well as aslangword forhomosexual.Associalattitudes towards homosexuality changed,fruitycame to be regarded as offensive, or at best, notpolitically correct.Thus, the gene was re-dubbedfruitless,alluding to the lack of offspring produced by flies with the mutation.[10]However, despite the original name and a continuing history of misleading inferences by the popular media, fruitless mutants primarily show defects in male-female courtship, though certain mutants cause male-male or female-female courtship.[11]
References
[edit]- ^abcdDemir E, Dickson BJ (June 2005)."fruitless splicing specifies male courtship behavior in Drosophila".Cell.121(5): 785–94.doi:10.1016/j.cell.2005.04.027.PMID15935764.S2CID14663286.
- ^Gailey DA, Billeter JC, Liu JH, Bauzon F, Allendorfer JB, Goodwin SF (March 2006)."Functional conservation of the fruitless male sex-determination gene across 250 Myr of insect evolution".Molecular Biology and Evolution.23(3): 633–43.doi:10.1093/molbev/msj070.PMID16319090.
- ^Burr C (June 1997)."Homosexuality and Biology, The Genetic Quest".The Atlantic.
- ^Wade N (December 13, 1996)."Mating Game of Fruit Fly Is Traced to a Single Gene".The New York Times.
- ^Sample, Ian (November 20, 2006)."Flies reveal gene that makes girls fight like boys".The Guardian.
- ^Cachero S, Ostrovsky AD, Yu JY, Dickson BJ, Jefferis GS (September 2010)."Sexual dimorphism in the fly brain".Current Biology.20(18): 1589–601.Bibcode:2010CBio...20.1589C.doi:10.1016/j.cub.2010.07.045.PMC2957842.PMID20832311.
- ^Kohl J, Ostrovsky AD, Frechter S, Jefferis GS (December 2013)."A bidirectional circuit switch reroutes pheromone signals in male and female brains".Cell.155(7): 1610–23.doi:10.1016/j.cell.2013.11.025.PMC3898676.PMID24360281.
- ^Ruta V, Datta SR, Vasconcelos ML, Freeland J, Looger LL, Axel R (December 2010). "A dimorphic pheromone circuit in Drosophila from sensory input to descending output".Nature.468(7324): 686–90.Bibcode:2010Natur.468..686R.doi:10.1038/nature09554.PMID21124455.S2CID4412743.
- ^Goldman TD, Arbeitman MN (November 2007)."Genomic and functional studies of Drosophila sex hierarchy regulated gene expression in adult head and nervous system tissues".PLOS Genetics.3(11): e216.doi:10.1371/journal.pgen.0030216.PMC2082469.PMID18039034.
- ^Gailey DA, Hall JC (April 1989)."Behavior and cytogenetics of fruitless in Drosophila melanogaster: different courtship defects caused by separate, closely linked lesions".Genetics.121(4): 773–85.doi:10.1093/genetics/121.4.773.PMC1203660.PMID2542123.
- ^"GeneBrief - fruitless".InteractiveFly.Society for Developmental Biology.