scholarly journals The Drosophila melanogaster pheromone Z4-11Al is encoded together with habitat olfactory cues and mediates species-specific communication

2016 ◽  
Author(s):  
Sebastien Lebreton ◽  
Felipe Borrero-Echeverry ◽  
Francisco Gonzalez ◽  
Marit Solum ◽  
Erika Wallin ◽  
...  

AbstractMate recognition in animals evolves during niche adaptation and involves habitat and social olfactory signals. Drosophila melanogaster is attracted to fermenting fruit for feeding and egg-laying. We show that, in addition, female flies release a pheromone (Z)-4-undecenal (Z4-11Al), that elicits flight attraction in both sexes. The biosynthetic precursor of Z4-11Al is the cuticular hydrocarbon (Z,Z)-7,11-heptacosadiene (7,11-HD), which is known to afford reproductive isolation between the sibling species D. melanogaster and D. simulans. A pair of alternatively spliced receptors, Or69aB and Or69aA, is tuned to Z4-11Al and to food olfactory cues, respectively. These receptors are co-expressed in the same olfactory sensory neurons, and feed into a neural circuit mediating species-specific, long-range communication: the close relative D. simulans, which shares food resources and co-occurs with D. melanogaster, does not respond. That Or69aA and Or69aB have adopted dual olfactory traits highlights the interplay of habitat and social signals in mate finding. These olfactory receptor genes afford a collaboration between natural and sexual selection, which has the potential to drive phylogenetic divergence.Significance StatementVolatile insect sex pheromones carry a message over a distance, they are perceived by dedicated olfactory receptors, and elicit a sequence of innate behaviours. Pheromones mediate specific mate recognition, but are embedded in and perceived together with environmental olfactory cues. We have identified the first long-range, species-specific pheromone in Drosophila melanogaster. A pair of spliced olfactory receptors, feeding into the same neural circuit, has developed a dual affinity to this pheromone and kairomones, encoding adult and larval food. Blends of this pheromone and kairomone specifically attract D. melanogaster, but not the close relative D. simulans. This becomes an excellent paradigm to study the interaction of social signals and habitat olfactory cues in premating reproductive isolation and phylogenetic divergence.

1985 ◽  
Vol 117 (4) ◽  
pp. 481-493 ◽  
Author(s):  
J.R. Byers ◽  
D.L. Struble ◽  
J.D. Lafontaine

AbstractThe species previously recognized as Euxoa ridingsiana (Grt.) is shown to be composed of a sympatric pair of sibling species, Euxoa ridingsiana (Grt.) and Euxoa maimes (Sm.), which in the laboratory will produce viable F1 hybrids but no F2. Results of F1 sib and backcrosses show that the F1 males are fertile and the F1 females are infertile. In mating-bias tests conducted in laboratory cages, 74% of matings were conspecific and 26% interspecific. Differences in the diel periodicities of mating, which are about 2 h out of phase, may account for the mating bias. The duration of development of E. ridingsiana in the laboratory and its seasonal flight period in the field are about 2 weeks in advance of that of E. maimes. However, there is considerable overlap of the flight periods and, with the tendency of females of both species to mate several times, it is unlikely that the difference in seasonal emergence is enough to effect reproductive isolation. It is evident that, under natural conditions, reproductive isolation can be maintained entirely by species-specific sex pheromones. This mechanism of reproductive isolation is, however, apparently ineffective when moths are confined in cages in the laboratory.Biogeographic considerations suggest that the differences in life-cycle timing and mating periodicities might have been adaptations to adjust development and reproduction to prevailing ancestral environments. If the initial differentiation of the 2 species occurred in isolation and included at least an incipient shift in the pheromonal mate-recognition system, it is possible that upon reestablishment of contact between ancestral populations the differences in life-cycle timing and mating periodicities acting in concert could have effected substantial, albeit incomplete, reproductive isolation. Subsequent selection to reinforce assortative mating to preserve coadapted gene complexes could then have resulted in differentiation of discrete pheromonal systems and attainment of species status.


2018 ◽  
Author(s):  
Rochishnu Dutta ◽  
Tejinder Singh Chechi ◽  
Ankit Yadav ◽  
Nagaraj Guru Prasad

AbstractThe ability of interlocus sexual conflict to facilitate reproductive isolation is widely anticipated. However, very few experimental evolutionary studies have convincingly demonstrated the evolution of reproductive isolation due to sexual conflict. Recently a study on replicate populations of Drosophila melanogaster under differential sexual conflict found that divergent mate preference evolved among replicate populations under high sexual conflict regime. The precopulatory isolating mechanism underlying such divergent mate preference could be sexual signals such as cuticular hydrocarbons since they evolve rapidly and are involved in D. melanogaster mate recognition. Using D. melanogaster replicates used in the previous study, we investigate whether cuticular hydrocarbon divergence bears signatures of sexually antagonistic coevolution that led to reproductive isolation among replicates of high sexual conflict regime. We found that D. melanogaster cuticular hydrocarbon profiles are sexually dimorphic. Although replicate populations under high sexual conflict displayed assortative mating, we found no significant differences in the cuticular hydrocarbon profile between the high and low sexual conflict regimes. Instead we find cuticular hydrocarbon divergence patterns to be suggestive of the Buridan’s Ass regime which is one of the six possible mechanisms to resolve sexual conflict. Sexual selection that co-vary between populations under high and low sexual conflict regimes may also have contributed to the evolution of cuticular hydrocarbons. This study indicates that population differentiation as a result of cuticular hydrocarbon divergence cannot be credited to sexual conflict despite high sexual conflict regime evolving divergent cuticular hydrocarbon profiles.


2008 ◽  
Vol 5 (2) ◽  
pp. 225-228 ◽  
Author(s):  
Philine G.D Feulner ◽  
Martin Plath ◽  
Jacob Engelmann ◽  
Frank Kirschbaum ◽  
Ralph Tiedemann

Mate choice is mediated by a range of sensory cues, and assortative mating based on these cues can drive reproductive isolation among diverging populations. A specific feature of mormyrid fish, the electric organ discharge (EOD), is used for electrolocation and intraspecific communication. We hypothesized that the EOD also facilitates assortative mating and ultimately promotes prezygotic reproductive isolation in African weakly electric fishes. Our behavioural experiments using live males as well as EOD playback demonstrated that female mate recognition is influenced by EOD signals and that females are attracted to EOD characteristics of conspecific males. The dual function of the EOD for both foraging and social communication (including mate recognition leading to assortative mating) underlines the importance of electric signal differentiation for the divergence of African weakly electric fishes. Thus, the EOD provides an intriguing mechanism promoting trophic divergence and reproductive isolation between two closely related Campylomormyrus species occurring in sympatry in the lower Congo rapids.


Author(s):  
Amanda Cicchino

Reproductive isolation is the hallmark of speciation as defined by the biological species concept. A species that is evolving towards reproductive isolation, but has not reached full isolation, is defined as an incipient species. One mechanism used by incipient species to further drive speciation is the use of mate recognition signals. The spring peeper, Pseudacris crucifer, is a North American frog that can be classified as an incipient species, as previous studies have found 6 distinct mitochondrial lineages within its range. Spring peepers use vocal signals for mate recognition and exhibit a female choice mating system where the males call to attract females. This study investigates the evolution of calling in spring peepers. Using calls from each lineage across the full range of spring peepers, I analyzed 11 different characteristics to determine whether the calls were different, and if so, which characteristics are being selected for. Preliminary evidence suggests that the calls between the lineages are distinct and that certain characteristics of the call are more heavily selected for than others. Full analysis on the data has not been completed at this time. This study will expand the understanding of the evolution of spring peepers, as well as offer insight into the role of mating systems on reproductive isolation.


2009 ◽  
Vol 276 (1676) ◽  
pp. 4215-4222 ◽  
Author(s):  
Abdoulaye Diabaté ◽  
Adama Dao ◽  
Alpha S. Yaro ◽  
Abdoulaye Adamou ◽  
Rodrigo Gonzalez ◽  
...  

Anopheles gambiae , the major malaria vector in Africa, can be divided into two subgroups based on genetic and ecological criteria. These two subgroups, termed the M and S molecular forms, are believed to be incipient species. Although they display differences in the ecological niches they occupy in the field, they are often sympatric and readily hybridize in the laboratory to produce viable and fertile offspring. Evidence for assortative mating in the field was recently reported, but the underlying mechanisms awaited discovery. We studied swarming behaviour of the molecular forms and investigated the role of swarm segregation in mediating assortative mating. Molecular identification of 1145 males collected from 68 swarms in Donéguébougou, Mali, over 2 years revealed a strict pattern of spatial segregation, resulting in almost exclusively monotypic swarms with respect to molecular form. We found evidence of clustering of swarms composed of individuals of a single molecular form within the village. Tethered M and S females were introduced into natural swarms of the M form to verify the existence of possible mate recognition operating within-swarm. Both M and S females were inseminated regardless of their form under these conditions, suggesting no within-mate recognition. We argue that our results provide evidence that swarm spatial segregation strongly contributes to reproductive isolation between the molecular forms in Mali. However this does not exclude the possibility of additional mate recognition operating across the range distribution of the forms. We discuss the importance of spatial segregation in the context of possible geographic variation in mechanisms of reproductive isolation.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. e00155-18 ◽  
Author(s):  
David R. Sannino ◽  
Adam J. Dobson ◽  
Katie Edwards ◽  
Esther R. Angert ◽  
Nicolas Buchon

ABSTRACTThe microbiota ofDrosophila melanogasterhas a substantial impact on host physiology and nutrition. Some effects may involve vitamin provisioning, but the relationships between microbe-derived vitamins, diet, and host health remain to be established systematically. We explored the contribution of microbiota in supplying sufficient dietary thiamine (vitamin B1) to supportD. melanogasterat different stages of its life cycle. Using chemically defined diets with different levels of available thiamine, we found that the interaction of thiamine concentration and microbiota did not affect the longevity of adultD. melanogaster. Likewise, this interplay did not have an impact on egg production. However, we determined that thiamine availability has a large impact on offspring development, as axenic offspring were unable to develop on a thiamine-free diet. Offspring survived on the diet only when the microbiota was present or added back, demonstrating that the microbiota was able to provide enough thiamine to support host development. Through gnotobiotic studies, we determined thatAcetobacter pomorum, a common member of the microbiota, was able to rescue development of larvae raised on the no-thiamine diet. Further, it was the only microbiota member that produced measurable amounts of thiamine when grown on the thiamine-free fly medium. Its close relativeAcetobacter pasteurianusalso rescued larvae; however, a thiamine auxotrophic mutant strain was unable to support larval growth and development. The results demonstrate that theD. melanogastermicrobiota functions to provision thiamine to its host in a low-thiamine environment.IMPORTANCEThere has been a long-standing assumption that the microbiota of animals provides their hosts with essential B vitamins; however, there is not a wealth of empirical evidence supporting this idea, especially for vitamin B1(thiamine). To determine whether this assumption is true, we usedDrosophila melanogasterand chemically defined diets with different thiamine concentrations as a model. We found that the microbiota does provide thiamine to its host, enough to allow the development of flies on a thiamine-free diet. The power of theDrosophila-microbiota system allowed us to determine that one microbiota member in particular,Acetobacter pomorum, is responsible for the thiamine provisioning. Thereby, our study verifies this long-standing hypothesis. Finally, the methods used in this work are applicable for interrogating the underpinnings of other aspects of the tripartite interaction between diet, host, and microbiota.


2006 ◽  
Vol 273 (1592) ◽  
pp. 1361-1368 ◽  
Author(s):  
Karin S Pfennig ◽  
Michael J Ryan

When interactions with heterospecifics prevent females from identifying conspecific mates, natural selection can promote the evolution of mating behaviours that minimize such interactions. Consequently, mating behaviours may diverge among conspecific populations in sympatry and in allopatry with heterospecifics. This divergence in conspecific mating behaviours—reproductive character displacement—can initiate speciation if mating behaviours become so divergent as to generate reproductive isolation between sympatric and allopatric conspecifics. We tested these ideas by using artificial neural networks to simulate the evolution of conspecific mate recognition in populations sympatric and allopatric with different heterospecifics. We found that advertisement calls diverged among the different conspecific populations. Consequently, networks strongly preferred calls from their own population to those from foreign conspecific populations. Thus, reproductive character displacement may promote reproductive isolation and, ultimately, speciation among conspecific populations.


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