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Wild African Drosophila melanogaster are seasonal specialists on marula fruits

Mansourian, Suzan LU ; Enjin, Anders LU ; Jirle, Erling LU ; Ramesh, Vedika; Rehermann, Guillermo; Becher, Paul G.; Pool, John E. and Stensmyr, Marcus LU (2018) In Current Biology 28(24). p.3-3968
Abstract
Although the vinegar fly Drosophila melanogaster is
arguably the most studied organism on the planet,
fundamental aspects of this species’ natural ecology
have remained enigmatic [1]. We have here investigated
a wild population of D. melanogaster from a
mopane forest in Zimbabwe. We find that these flies
are closely associated with marula fruit (Sclerocarya
birrea
) and propose that this seasonally abundant
and predominantly Southern African fruit is a key
ancestral host of D. melanogaster. Moreover, when
fruiting, marula is nearly exclusively used by
D. melanogaster, suggesting that these forest-dwelling
D. melanogaster are seasonal specialists, in... (More)
Although the vinegar fly Drosophila melanogaster is
arguably the most studied organism on the planet,
fundamental aspects of this species’ natural ecology
have remained enigmatic [1]. We have here investigated
a wild population of D. melanogaster from a
mopane forest in Zimbabwe. We find that these flies
are closely associated with marula fruit (Sclerocarya
birrea
) and propose that this seasonally abundant
and predominantly Southern African fruit is a key
ancestral host of D. melanogaster. Moreover, when
fruiting, marula is nearly exclusively used by
D. melanogaster, suggesting that these forest-dwelling
D. melanogaster are seasonal specialists, in a
similar manner to, e.g., Drosophila erecta on screw
pine cones [2]. We further demonstrate that the
main chemicals released by marula activate odorant
receptors that mediate species-specific host choice
(Or22a) [3, 4] and oviposition site selection (Or19a)
[5]. The Or22a-expressing neurons—ab3A—respond
strongly to the marula ester ethyl isovalerate, a volatile
rarely encountered in high amounts in other fruit.
We also show that Or22a differs among African populations
sampled from a wide range of habitats, in
line with a function associated with host fruit usage.
Flies from Southern Africa, most of which carry a
distinct allele at the Or22a/Or22b locus, have ab3A
neurons that are more sensitive to ethyl isovalerate
than, e.g., European flies. Finally, we discuss the
possibility that marula, which is also a culturally
and nutritionally important resource to humans,
may have helped the transition to commensalism in
D. melanogaster. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
The Fly, commensialism
in
Current Biology
volume
28
issue
24
pages
21 pages
publisher
Elsevier
external identifiers
  • scopus:85058225591
ISSN
1879-0445
language
English
LU publication?
yes
id
89c58c28-368f-4749-a6ee-4f7e610b2e8e
date added to LUP
2018-12-07 13:52:14
date last changed
2019-07-09 04:38:24
@article{89c58c28-368f-4749-a6ee-4f7e610b2e8e,
  abstract     = {Although the vinegar fly <i>Drosophila melanogaster</i> is<br/>arguably the most studied organism on the planet,<br/>fundamental aspects of this species’ natural ecology<br/>have remained enigmatic [1]. We have here investigated<br/>a wild population of <i>D. melanogaster</i> from a<br/>mopane forest in Zimbabwe. We find that these flies<br/>are closely associated with marula fruit (<i>Sclerocarya<br/>birrea</i>) and propose that this seasonally abundant<br/>and predominantly Southern African fruit is a key<br/>ancestral host of <i>D. melanogaster</i>. Moreover, when<br/>fruiting, marula is nearly exclusively used by<br/><i>D. melanogaster</i>, suggesting that these forest-dwelling<br/><i>D. melanogaster</i> are seasonal specialists, in a<br/>similar manner to, e.g., <i>Drosophila erecta</i> on screw<br/>pine cones [2]. We further demonstrate that the<br/>main chemicals released by marula activate odorant<br/>receptors that mediate species-specific host choice<br/>(Or22a) [3, 4] and oviposition site selection (Or19a)<br/>[5]. The Or22a-expressing neurons—ab3A—respond<br/>strongly to the marula ester ethyl isovalerate, a volatile<br/>rarely encountered in high amounts in other fruit.<br/>We also show that Or22a differs among African populations<br/>sampled from a wide range of habitats, in<br/>line with a function associated with host fruit usage.<br/>Flies from Southern Africa, most of which carry a<br/>distinct allele at the Or22a/Or22b locus, have ab3A<br/>neurons that are more sensitive to ethyl isovalerate<br/>than, e.g., European flies. Finally, we discuss the<br/>possibility that marula, which is also a culturally<br/>and nutritionally important resource to humans,<br/>may have helped the transition to commensalism in<br/><i>D. melanogaster</i>.},
  author       = {Mansourian, Suzan and Enjin, Anders and Jirle, Erling and Ramesh, Vedika and Rehermann, Guillermo and Becher, Paul G. and Pool, John E. and Stensmyr, Marcus},
  issn         = {1879-0445},
  keyword      = {The Fly,commensialism},
  language     = {eng},
  month        = {12},
  number       = {24},
  pages        = {3--3968},
  publisher    = {Elsevier},
  series       = {Current Biology},
  title        = {Wild African <i>Drosophila melanogaster</i> are seasonal specialists on marula fruits},
  volume       = {28},
  year         = {2018},
}