1
|
Hoikkala A, Poikela N. Adaptation and ecological speciation in seasonally varying environments at high latitudes: Drosophila virilis group. Fly (Austin) 2022; 16:85-104. [PMID: 35060806 PMCID: PMC8786326 DOI: 10.1080/19336934.2021.2016327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Living in high latitudes and altitudes sets specific requirements on species’ ability to forecast seasonal changes and to respond to them in an appropriate way. Adaptation into diverse environmental conditions can also lead to ecological speciation through habitat isolation or by inducing changes in traits that influence assortative mating. In this review, we explain how the unique time-measuring systems of Drosophila virilis group species have enabled the species to occupy high latitudes and how the traits involved in species reproduction and survival exhibit strong linkage with latitudinally varying photoperiodic and climatic conditions. We also describe variation in reproductive barriers between the populations of two species with overlapping distributions and show how local adaptation and the reinforcement of prezygotic barriers have created partial reproductive isolation between conspecific populations. Finally, we consider the role of species-specific chromosomal inversions and the X chromosome in the development of reproductive barriers between diverging lineages.
Collapse
Affiliation(s)
- Anneli Hoikkala
- Department of Biological and Environmental Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Noora Poikela
- Department of Biological and Environmental Sciences, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
2
|
Wiberg RAW, Tyukmaeva V, Hoikkala A, Ritchie MG, Kankare M. Cold adaptation drives population genomic divergence in the ecological specialist, Drosophila montana. Mol Ecol 2021; 30:3783-3796. [PMID: 34047417 DOI: 10.1111/mec.16003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/10/2021] [Accepted: 05/20/2021] [Indexed: 12/18/2022]
Abstract
Detecting signatures of ecological adaptation in comparative genomics is challenging, but analysing population samples with characterised geographic distributions, such as clinal variation, can help identify genes showing covariation with important ecological variation. Here, we analysed patterns of geographic variation in the cold-adapted species Drosophila montana across phenotypes, genotypes and environmental conditions and tested for signatures of cold adaptation in population genomic divergence. We first derived the climatic variables associated with the geographic distribution of 24 populations across two continents to trace the scale of environmental variation experienced by the species, and measured variation in the cold tolerance of the flies of six populations from different geographic contexts. We then performed pooled whole genome sequencing of these six populations, and used Bayesian methods to identify SNPs where genetic differentiation is associated with both climatic variables and the population phenotypic measurements, while controlling for effects of demography and population structure. The top candidate SNPs were enriched on the X and fourth chromosomes, and they also lay near genes implicated in other studies of cold tolerance and population divergence in this species and its close relatives. We conclude that ecological adaptation has contributed to the divergence of D. montana populations throughout the genome and in particular on the X and fourth chromosomes, which also showed highest interpopulation FST . This study demonstrates that ecological selection can drive genomic divergence at different scales, from candidate genes to chromosome-wide effects.
Collapse
Affiliation(s)
- R A W Wiberg
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, UK
| | - V Tyukmaeva
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - A Hoikkala
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - M G Ritchie
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, UK
| | - M Kankare
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
3
|
Garlovsky MD, Yusuf LH, Ritchie MG, Snook RR. Within-population sperm competition intensity does not predict asymmetry in conpopulation sperm precedence. Philos Trans R Soc Lond B Biol Sci 2020; 375:20200071. [PMID: 33070721 PMCID: PMC7661444 DOI: 10.1098/rstb.2020.0071] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Postcopulatory sexual selection can generate evolutionary arms races between the sexes resulting in the rapid coevolution of reproductive phenotypes. As traits affecting fertilization success diverge between populations, postmating prezygotic (PMPZ) barriers to gene flow may evolve. Conspecific sperm precedence is a form of PMPZ isolation thought to evolve early during speciation yet has mostly been studied between species. Here, we show conpopulation sperm precedence (CpSP) between Drosophila montana populations. Using Pool-seq genomic data we estimate divergence times and ask whether PMPZ isolation evolved in the face of gene flow. We find models incorporating gene flow fit the data best indicating populations experienced considerable gene flow during divergence. We find CpSP is asymmetric and mirrors asymmetry in non-competitive PMPZ isolation, suggesting these phenomena have a shared mechanism. However, we show asymmetry is unrelated to the strength of postcopulatory sexual selection acting within populations. We tested whether overlapping foreign and coevolved ejaculates within the female reproductive tract altered fertilization success but found no effect. Our results show that neither time since divergence nor sperm competitiveness predicts the strength of PMPZ isolation. We suggest that instead cryptic female choice or mutation-order divergence may drive divergence of postcopulatory phenotypes resulting in PMPZ isolation. This article is part of the theme issue ‘Fifty years of sperm competition’.
Collapse
Affiliation(s)
- Martin D Garlovsky
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Leeban H Yusuf
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
| | - Michael G Ritchie
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
| | - Rhonda R Snook
- Department of Zoology, Stockholm University, Stockholm 106-91, Sweden
| |
Collapse
|
4
|
Garlovsky MD, Snook RR. Persistent postmating, prezygotic reproductive isolation between populations. Ecol Evol 2018; 8:9062-9073. [PMID: 30271566 PMCID: PMC6157668 DOI: 10.1002/ece3.4441] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/23/2018] [Accepted: 07/09/2018] [Indexed: 12/23/2022] Open
Abstract
Studying reproductive barriers between populations of the same species is critical to understand how speciation may proceed. Growing evidence suggests postmating, prezygotic (PMPZ) reproductive barriers play an important role in the evolution of early taxonomic divergence. However, the contribution of PMPZ isolation to speciation is typically studied between species in which barriers that maintain isolation may not be those that contributed to reduced gene flow between populations. Moreover, in internally fertilizing animals, PMPZ isolation is related to male ejaculate-female reproductive tract incompatibilities but few studies have examined how mating history of the sexes can affect the strength of PMPZ isolation and the extent to which PMPZ isolation is repeatable or restricted to particular interacting genotypes. We addressed these outstanding questions using multiple populations of Drosophila montana. We show a recurrent pattern of PMPZ isolation, with flies from one population exhibiting reproductive incompatibility in crosses with all three other populations, while those three populations were fully fertile with each other. Reproductive incompatibility is due to lack of fertilization and is asymmetrical, affecting female fitness more than males. There was no effect of male or female mating history on reproductive incompatibility, indicating that PMPZ isolation persists between populations. We found no evidence of variability in fertilization outcomes attributable to different female × male genotype interactions, and in combination with our other results, suggests that PMPZ isolation is not driven by idiosyncratic genotype × genotype interactions. Our results show PMPZ isolation as a strong, consistent barrier to gene flow early during speciation and suggest several targets of selection known to affect ejaculate-female reproductive tract interactions within species that may cause this PMPZ isolation.
Collapse
Affiliation(s)
| | - Rhonda R. Snook
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
- Department of ZoologyStockholm UniversityStockholmSweden
| |
Collapse
|
5
|
Parker DJ, Wiberg RAW, Trivedi U, Tyukmaeva VI, Gharbi K, Butlin RK, Hoikkala A, Kankare M, Ritchie MG. Inter and Intraspecific Genomic Divergence in Drosophila montana Shows Evidence for Cold Adaptation. Genome Biol Evol 2018; 10:2086-2101. [PMID: 30010752 PMCID: PMC6107330 DOI: 10.1093/gbe/evy147] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2018] [Indexed: 12/25/2022] Open
Abstract
The genomes of species that are ecological specialists will likely contain signatures of genomic adaptation to their niche. However, distinguishing genes related to ecological specialism from other sources of selection and more random changes is a challenge. Here, we describe the genome of Drosophila montana, which is the most extremely cold-adapted Drosophila species known. We use branch tests to identify genes showing accelerated divergence in contrasts between cold- and warm-adapted species and identify about 250 genes that show differences, possibly driven by a lower synonymous substitution rate in cold-adapted species. We also look for evidence of accelerated divergence between D. montana and D. virilis, a previously sequenced relative, but do not find strong evidence for divergent selection on coding sequence variation. Divergent genes are involved in a variety of functions, including cuticular and olfactory processes. Finally, we also resequenced three populations of D. montana from across its ecological and geographic range. Outlier loci were more likely to be found on the X chromosome and there was a greater than expected overlap between population outliers and those genes implicated in cold adaptation between Drosophila species, implying some continuity of selective process at these different evolutionary scales.
Collapse
Affiliation(s)
- Darren J Parker
- Department of Biological and Environmental Science, University of Jyväskylä, Finland
- Center for Biological Diversity, School of Biology, University of St. Andrews, Fife, United Kingdom
- Department of Ecology and Evolution, University of Lausanne, Biophore, Switzerland
| | - R Axel W Wiberg
- Center for Biological Diversity, School of Biology, University of St. Andrews, Fife, United Kingdom
| | - Urmi Trivedi
- Edinburgh Genomics, School of Biological Sciences, University of Edinburgh, United Kingdom
| | - Venera I Tyukmaeva
- Department of Biological and Environmental Science, University of Jyväskylä, Finland
| | - Karim Gharbi
- Edinburgh Genomics, School of Biological Sciences, University of Edinburgh, United Kingdom
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | - Roger K Butlin
- Department of Animal and Plant Sciences, The University of Sheffield, UK
- Department of Marine Sciences, University of Gothenburg, Göteborg, Sweden
| | - Anneli Hoikkala
- Department of Biological and Environmental Science, University of Jyväskylä, Finland
| | - Maaria Kankare
- Department of Biological and Environmental Science, University of Jyväskylä, Finland
| | - Michael G Ritchie
- Center for Biological Diversity, School of Biology, University of St. Andrews, Fife, United Kingdom
| |
Collapse
|
6
|
Ala-Honkola O, Ritchie MG, Veltsos P. Postmating-prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm competition. Ecol Evol 2016; 6:1679-91. [PMID: 27087932 PMCID: PMC4801965 DOI: 10.1002/ece3.1995] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/17/2016] [Accepted: 01/18/2016] [Indexed: 12/23/2022] Open
Abstract
Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early‐stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate rapidly), we set up double matings of all possible crosses between the same populations to test whether competitive effects between ejaculates influence this PMPZ isolation. We measured premating isolation in no‐choice tests, female fecundity, fertility and egg‐to‐adult viability after single and double matings as well as second‐male paternity success (P2). Surprisingly, we found no PMPZ reproductive isolation between the two populations under a competitive setting, indicating no difficulty of sperm from Vancouver males to fertilize Colorado eggs after double matings. While there were subtle differences in how P2 changed over time, suggesting that Vancouver males’ sperm are somewhat less competitive in a first‐male role within Colorado females, these effects did not translate into differences in overall P2. Fertilisation success can thus differ dramatically between competitive and noncompetitive conditions, perhaps because the males that mate second produce higher quality ejaculates in response to sperm competition. We suggest that unlike in more divergent species comparisons, where sperm competition typically increases reproductive isolation, ejaculate tailoring can reduce the potential for PMPZ isolation when recently diverged populations interbreed.
Collapse
Affiliation(s)
- Outi Ala-Honkola
- Department of Biological and Environmental Science University of Jyvaskyla PO Box 35 FI- 40014 Jyvaskyla Finland
| | - Michael G Ritchie
- Centre for Biological Diversity School of Biology University of St Andrews St Andrews KY16 9TS UK
| | - Paris Veltsos
- Department of Ecology and Evolution University of Lausanne Biophore Building Lausanne 1015 Switzerland
| |
Collapse
|
7
|
Veltsos P, Gregson E, Morrissey B, Slate J, Hoikkala A, Butlin RK, Ritchie MG. The genetic architecture of sexually selected traits in two natural populations of Drosophila montana. Heredity (Edinb) 2015. [PMID: 26198076 DOI: 10.1038/hdy.2015.63] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We investigated the genetic architecture of courtship song and cuticular hydrocarbon traits in two phygenetically distinct populations of Drosophila montana. To study natural variation in these two important traits, we analysed within-population crosses among individuals sampled from the wild. Hence, the genetic variation analysed should represent that available for natural and sexual selection to act upon. In contrast to previous between-population crosses in this species, no major quantitative trait loci (QTLs) were detected, perhaps because the between-population QTLs were due to fixed differences between the populations. Partitioning the trait variation to chromosomes suggested a broadly polygenic genetic architecture of within-population variation, although some chromosomes explained more variation in one population compared with the other. Studies of natural variation provide an important contrast to crosses between species or divergent lines, but our analysis highlights recent concerns that segregating variation within populations for important quantitative ecological traits may largely consist of small effect alleles, difficult to detect with studies of moderate power.
Collapse
Affiliation(s)
- P Veltsos
- Centre for Biological Diversity, University of St Andrews, St Andrews, UK
| | - E Gregson
- Animal & Plant Sciences, University of Sheffield, Alfred Denny Building, Sheffield, UK
| | - B Morrissey
- Animal & Plant Sciences, University of Sheffield, Alfred Denny Building, Sheffield, UK
| | - J Slate
- Animal & Plant Sciences, University of Sheffield, Alfred Denny Building, Sheffield, UK
| | - A Hoikkala
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - R K Butlin
- Animal & Plant Sciences, University of Sheffield, Alfred Denny Building, Sheffield, UK.,Sven Lovén Centre-Tjärnö, University of Gothenburg, Strömstad, Sweden
| | - M G Ritchie
- Centre for Biological Diversity, University of St Andrews, St Andrews, UK
| |
Collapse
|
8
|
Jennings JH, Snook RR, Hoikkala A. Reproductive isolation among allopatric Drosophila montana populations. Evolution 2015; 68:3095-108. [PMID: 25302639 DOI: 10.1111/evo.12535] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022]
Abstract
An outstanding goal in speciation research is to trace the mode and tempo of the evolution of barriers to gene flow. Such research benefits from studying incipient speciation, in which speciation between populations has not yet occurred, but where multiple potential mechanisms of reproductive isolation (RI: i.e., premating, postmating-prezygotic (PMPZ), and postzygotic barriers) may act. We used such a system to investigate these barriers among allopatric populations of Drosophila montana. In all heteropopulation crosses we found premating (sexual) isolation, which was either symmetric or asymmetric depending on the population pair compared. Postmating isolation was particularly strong in crosses involving males from one of the study populations, and while sperm were successfully transferred, stored, and motile, we experimentally demonstrated that the majority of eggs produced were unfertilized. Thus, we identified the nature of a PMPZ incompatibility. There was no evidence of intrinsic postzygotic effects. Measures of absolute and relative strengths of pre- and postmating barriers showed that populations differed in the mode and magnitude of RI barriers. Our results indicate that incipient RI among populations can be driven by different contributions of both premating and PMPZ barriers occurring between different population pairs and without the evolution of postzygotic barriers.
Collapse
Affiliation(s)
- Jackson H Jennings
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland; Current Address: Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, 72701
| | | | | |
Collapse
|
9
|
Jennings JH, Etges WJ, Schmitt T, Hoikkala A. Cuticular hydrocarbons of Drosophila montana: geographic variation, sexual dimorphism and potential roles as pheromones. JOURNAL OF INSECT PHYSIOLOGY 2014; 61:16-24. [PMID: 24373710 DOI: 10.1016/j.jinsphys.2013.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 11/21/2013] [Accepted: 12/03/2013] [Indexed: 05/09/2023]
Abstract
Sexual selection within populations can play an important role in speciation when divergence in mating signals and their corresponding preferences occur along different coevolutionary trajectories in different populations. In insects, one potential target of sexual selection is the blend of cuticular hydrocarbons (CHCs), which often show intra- and interspecific variation, sexual dimorphism and may act as pheromones. In Drosophila montana, a cold-adapted, circumboreal member of the Drosophila virilis species group, flies from different populations have been found to show significant premating isolation as well as variation in male mating signal (song) and female preference. While the role of male courtship song in mate choice has been studied extensively, CHCs in this species have received little attention. In this study, we identified most of the CHCs found on the cuticle of D. montana and characterized population divergence and sexual dimorphism of CHC profiles among flies established from three natural populations - one European and two North American. We also studied their potential role as pheromones by analyzing CHCs of flies used in female-choice mating experiments. We report significant population×sex effects on CHC profiles, as well as significant relationships between some CHC principal components and particular mating behaviours, such as female attractiveness and male mating success, providing evidence that CHCs may play a role in mate choice in this species. The study also provides evidence for variation in the degree to which CHCs play a role in chemical communication among these populations, which may have an influence on the speciation process itself, and could be due to variation in interactions with other closely-related species that occur sympatrically with D. montana in some, but not other, parts of its distribution.
Collapse
Affiliation(s)
- Jackson H Jennings
- Program in Ecology and Evolutionary Biology, Department of Biological Sciences, University of Arkansas, AR 72701, USA; Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä 40014, Finland.
| | - William J Etges
- Program in Ecology and Evolutionary Biology, Department of Biological Sciences, University of Arkansas, AR 72701, USA
| | - Thomas Schmitt
- Department of Animal Ecology and Tropical Biology, Faculty of Biology, University of Würzburg, Würzburg 97074, Germany; Ecological Networks, Faculty of Biology, Technical University of Darmstadt, Germany
| | - Anneli Hoikkala
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä 40014, Finland
| |
Collapse
|
10
|
Salminen TS, Hoikkala A. Effect of temperature on the duration of sensitive period and on the number of photoperiodic cycles required for the induction of reproductive diapause in Drosophila montana. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:450-457. [PMID: 23428942 DOI: 10.1016/j.jinsphys.2013.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 02/11/2013] [Accepted: 02/12/2013] [Indexed: 06/01/2023]
Abstract
Correct timing of the induction of photoperiodic reproductive diapause has been found to play an important role in the life cycle of several northern insect species. However, even when the environmental conditions are favourable for diapause, the switch to diapause can only take place when the females are in a proper developmental and physiological stage, referred to as the sensitive period (SP) for diapause. We have previously shown that in a northern fly species, Drosophila montana, the developmental pathway of the ovaries (direct maturation vs. diapause) is determined by photoperiodic cues that the females receive after eclosion. Here, we have studied the effects of temperature on the duration of the sensitive period, and on the number of short day cycles that the females have to experience before half of them will enter diapause (RDN=required day number). Ovarian development rate of the females was first traced under long and short day conditions in 16 and 19°C, and then reciprocal transfers were done between the diapause-inducing short day conditions, and the vitellogenesis-inducing long day conditions to determine the females' SP and RDN. Close to 100% of the females of all study strains entered reproductive diapause under short day conditions in 16°C, and the same occurred also in 19°C in strains from the more northern univoltine population. The sensitive period for diapause induction was affected by temperature, as it was shorter in higher temperature (circa 8 days in 16°C and 4-5 days in 19°C), and was restricted by the faster development rate of the ovaries. D. montana females had to experience approximately three short day cycles during the sensitive period, before half of them entered diapause, which also explains the decrease in the number of diapausing females at higher temperatures. This system clearly differs from that of the more southern Drosophila species, e.g. D. melanogaster, where the females' developmental pathway is determined already during the first day after eclosion.
Collapse
Affiliation(s)
- Tiina S Salminen
- Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland.
| | | |
Collapse
|
11
|
Salminen TS, Vesala L, Hoikkala A. Photoperiodic regulation of life-history traits before and after eclosion: egg-to-adult development time, juvenile body mass and reproductive diapause in Drosophila montana. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1541-1547. [PMID: 23026647 DOI: 10.1016/j.jinsphys.2012.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 09/13/2012] [Accepted: 09/18/2012] [Indexed: 06/01/2023]
Abstract
Photoperiod is the main environmental cue used by northern insects to predict the forthcoming seasonal changes and to adjust their life-history traits to fit these changes. We studied the effects of photoperiod on egg-to-adult development time, juvenile body mass and female reproductive diapause in two northern Drosophila montana populations with different patterns of voltinism. The most interesting findings were consistent between the populations: (1) when maintained before eclosion in short day conditions, representing early autumn, the flies developed faster and were lighter than when maintained in long day conditions, representing early summer, (2) photoperiodic time measurement is apparently reset after eclosion, adjusting the flies' development according to post eclosion conditions, (3) the sensitive period for diapause induction took place after eclosion and (4) there was no direct connection between females' egg-to-adult development time and their reproductive state at adulthood, which suggests that these traits can be determined by photoperiodic cues through different time measurement systems. Independence of photoperiodic regulation of life-history traits before and after eclosion enable D. montana flies to respond to changing photoperiods on a short time scale and match their life-history traits according to seasons.
Collapse
Affiliation(s)
- T S Salminen
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland.
| | | | | |
Collapse
|
12
|
Puniamoorthy N, Blanckenhorn WU, Schäfer MA. Differential investment in pre- vs. post-copulatory sexual selection reinforces a cross-continental reversal of sexual size dimorphism inSepsis punctum(Diptera: Sepsidae). J Evol Biol 2012; 25:2253-63. [DOI: 10.1111/j.1420-9101.2012.02605.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/15/2012] [Accepted: 07/23/2012] [Indexed: 11/28/2022]
Affiliation(s)
| | - W. U. Blanckenhorn
- Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Zurich; Switzerland
| | - M. A. Schäfer
- Institute of Evolutionary Biology and Environmental Studies; University of Zurich; Zurich; Switzerland
| |
Collapse
|
13
|
Two distinct genomic regions, harbouring the period and fruitless genes, affect male courtship song in Drosophila montana. Heredity (Edinb) 2012; 108:602-8. [PMID: 22234247 DOI: 10.1038/hdy.2011.129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Acoustic signals often have a significant role in pair formation and in species recognition. Determining the genetic basis of signal divergence will help to understand signal evolution by sexual selection and its role in the speciation process. An earlier study investigated quantitative trait locus for male courtship song carrier frequency (FRE) in Drosophila montana using microsatellite markers. We refined this study by adding to the linkage map markers for 10 candidate genes known to affect song production in Drosophila melanogaster. We also extended the analyses to additional song characters (pulse train length (PTL), pulse number (PN), interpulse interval, pulse length (PL) and cycle number (CN)). Our results indicate that loci in two different regions of the genome control distinct features of the courtship song. Pulse train traits (PTL and PN) mapped to the X chromosome, showing significant linkage with the period gene. In contrast, characters related to song pulse properties (PL, CN and carrier FRE) mapped to the region of chromosome 2 near the candidate gene fruitless, identifying these genes as suitable loci for further investigations. In previous studies, the pulse train traits have been found to vary substantially between Drosophila species, and so are potential species recognition signals, while the pulse traits may be more important in intra-specific mate choice.
Collapse
|
14
|
Veltsos P, Wicker-Thomas C, Butlin RK, Hoikkala A, Ritchie MG. Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana. Ecol Evol 2012; 2:80-94. [PMID: 22408728 PMCID: PMC3297180 DOI: 10.1002/ece3.75] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/08/2011] [Accepted: 10/14/2011] [Indexed: 11/26/2022] Open
Abstract
Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F(1-3) offspring of wild-collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify the targets of sexual selection on song, CHCs, and both traits combined within the populations. Three measures of courtship outcome were used as fitness proxies. They were the probability of mating, mating latency, and the production of rejection song by females, and showed patterns of association with different traits that included both linear and quadratic selection. Courtship song predicted courtship outcome better than CHCs and the signal modalities acted in an additive rather than synergistic manner. Selection was generally consistent in direction and strength between the two populations and favored males that sang more vigorously. Sexual selection differed in the extent, strength, and nature on some of the traits between populations. However, the differences in the directionality of selection detected were not a good predictor of population differences. In addition, a character previously shown to be important for species recognition, interpulse interval, was found to be under sexual selection. Our results highlight the complexity of understanding the relationship between within-population sexual selection and population differences. Sexual selection alone cannot predict differences between populations.
Collapse
Affiliation(s)
- Paris Veltsos
- School of Biology, University of St Andrews, Dyers Brae HouseSt Andrews, Fife, KY16 9TH, United Kingdom
| | - Claude Wicker-Thomas
- UPR 9034 Laboratoire Evolution, Génomes et Spéciation (LEGS), CNRS, Avenue de la TerrasseBât. 13, Jpg sur Yvette Cedex, 91198, France
| | - Roger K Butlin
- Animal & Plant Sciences, University of Sheffield, Alfred Denny BuildingSheffield, S10 2TN, UK
| | - Anneli Hoikkala
- Department of Biological and Environmental Science, University of JyvãskylãSurvontie 9, Jyvãskylã, 40014, Finland
| | - Michael G Ritchie
- School of Biology, University of St Andrews, Dyers Brae HouseSt Andrews, Fife, KY16 9TH, United Kingdom
| |
Collapse
|
15
|
Schäfer MA, Routtu J, Vieira J, Hoikkala A, Ritchie MG, Schlötterer C. Multiple quantitative trait loci influence intra-specific variation in genital morphology between phylogenetically distinct lines of Drosophila montana. J Evol Biol 2011; 24:1879-86. [PMID: 21635604 DOI: 10.1111/j.1420-9101.2011.02316.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The evolution of animal genitalia has gained renewed interest because of their potential roles during sexual selection and early stages of species formation. Although central to understanding the evolutionary process, knowledge of the genetic basis of natural variation in genital morphology is limited to a very few species. Using an outbred cross between phylogenetically distinct lines of Drosophila montana, we characterized quantitative trait loci (QTLs) affecting the size and shape of the distiphallus, a prominent part of the male intromittent organ. Our microsatellite-based linkage analysis shows that intra-specific variation in the distiphallus involves several QTLs of largely additive effect and that a highly significant QTL co-localizes with the same inversion where we have earlier localized a large QTL for a sexually selected courtship song trait. The latter indicates that inversions can play an important role in shaping the evolution of rapidly evolving traits with a potential influence on speciation.
Collapse
Affiliation(s)
- M A Schäfer
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
| | | | | | | | | | | |
Collapse
|
16
|
Jennings JH, Mazzi D, Ritchie MG, Hoikkala A. Sexual and postmating reproductive isolation between allopatric Drosophila montana populations suggest speciation potential. BMC Evol Biol 2011; 11:68. [PMID: 21396136 PMCID: PMC3065424 DOI: 10.1186/1471-2148-11-68] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 03/14/2011] [Indexed: 11/27/2022] Open
Abstract
Background Widely distributed species with populations adapted to different environmental conditions can provide valuable opportunities for tracing the onset of reproductive incompatibilities and their role in the speciation process. Drosophila montana, a D. virilis group species found in high latitude boreal forests in Nearctic and Palearctic regions around the globe, could be an excellent model system for studying the early stages of speciation, as a wealth of information concerning this species' ecology, mating system, life history, genetics and phylogeography is available. However, reproductive barriers between populations have hereto not been investigated. Results We report both pre- and postmating barriers to reproduction between flies from European (Finnish) and North American (Canadian) populations of Drosophila montana. Using a series of mate-choice designs, we show that flies from these two populations mate assortatively (i.e., exhibit significant sexual isolation) while emphasizing the importance of experimental design in these kinds of studies. We also assessed potential postmating isolation by quantifying egg and progeny production in intra- and interpopulation crosses and show a significant one-way reduction in progeny production, affecting both male and female offspring equally. Conclusion We provide evidence that allopatric D. montana populations exhibit reproductive isolation and we discuss the potential mechanisms involved. Our data emphasize the importance of experimental design in studies on premating isolation between recently diverged taxa and suggest that postmating barriers may be due to postcopulatory-prezygotic mechanisms. D. montana populations seem to be evolving multiple barriers to gene flow in allopatry and our study lays the groundwork for future investigations of the genetic and phenotypic mechanisms underlying these barriers.
Collapse
Affiliation(s)
- Jackson H Jennings
- Centre of Excellence in Evolutionary Research, Department of Biological and Environmental Science, P.O. Box 35, 40014 University of Jyväskylä, Finland.
| | | | | | | |
Collapse
|
17
|
SCHÄFER MA, MAZZI D, KLAPPERT K, KAURANEN H, VIEIRA J, HOIKKALA A, RITCHIE MG, SCHLÖTTERER C. A microsatellite linkage map forDrosophila montanashows large variation in recombination rates, and a courtship song trait maps to an area of low recombination. J Evol Biol 2010; 23:518-27. [DOI: 10.1111/j.1420-9101.2009.01916.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
18
|
Kankare M, Salminen T, Laiho A, Vesala L, Hoikkala A. Changes in gene expression linked with adult reproductive diapause in a northern malt fly species: a candidate gene microarray study. BMC Ecol 2010; 10:3. [PMID: 20122138 PMCID: PMC2822739 DOI: 10.1186/1472-6785-10-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 02/01/2010] [Indexed: 11/16/2022] Open
Abstract
Background Insect diapause is an important biological process which involves many life-history parameters important for survival and reproductive fitness at both individual and population level. Drosophila montana, a species of D. virilis group, has a profound photoperiodic reproductive diapause that enables the adult flies to survive through the harsh winter conditions of high latitudes and altitudes. We created a custom-made microarray for D. montana with 101 genes known to affect traits important in diapause, photoperiodism, reproductive behaviour, circadian clock and stress tolerance in model Drosophila species. This array gave us a chance to filter out genes showing expression changes during photoperiodic reproductive diapause in a species adapted to live in northern latitudes with high seasonal changes in environmental conditions. Results Comparisons among diapausing, reproducing and young D. montana females revealed expression changes in 24 genes on microarray; for example in comparison between diapausing and reproducing females one gene (Drosophila cold acclimation gene, Dca) showed up-regulation and 15 genes showed down-regulation in diapausing females. Down-regulation of seven of these genes was specific to diapause state while in five genes the expression changes were linked with the age of the females rather than with their reproductive status. Also, qRT-PCR experiments confirmed couch potato (cpo) gene to be involved in diapause of D. montana. Conclusions A candidate gene microarray proved to offer a practical and cost-effective way to trace genes that are likely to play an important role in photoperiodic reproductive diapause and further in adaptation to seasonally varying environmental conditions. The present study revealed two genes, Dca and cpo, whose role in photoperiodic diapause in D. montana is worth of studying in more details. Also, further studies using the candidate gene microarray with more specific experimental designs and target tissues may reveal additional genes with more restricted expression patterns.
Collapse
Affiliation(s)
- Maaria Kankare
- Centre of Excellence in Evolutionary Research, Department of Biological and Environmental Science, P.O. Box 35, 40014 University of Jyväskylä, Finland
| | | | | | | | | |
Collapse
|
19
|
Reis M, Vieira CP, Morales-Hojas R, Vieira J. An old bilbo-like non-LTR retroelement insertion provides insight into the relationship of species of the virilis group. Gene 2008; 425:48-55. [PMID: 18775768 DOI: 10.1016/j.gene.2008.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 07/18/2008] [Accepted: 08/05/2008] [Indexed: 10/21/2022]
Abstract
In Drosophila, at the population and species level, fixation of a TE insertion is an unlikely fate. Of the few reported fixations at the species level most involve non-LTR retroelements. In this work we report the fixation of a non-LTR retroelement in five species (Drosophila littoralis, Drosophila virilis, Drosophila lummei, Drosophila americana and Drosophila novamexicana) of the virilis group of Drosophila. In most species, this TE insertion is being lost through the accumulation of small deletions, but there is also evidence for the accumulation of large deletions. In the americana lineage an insertion of about 900 bp of the non-LTR retroelement is a marker for the Xc inversion. This insertion is, at most, 80 kb away from the basal Xc inversion breakpoint. The presence of a bilbo-like element in D. littoralis but not in D. kanekoi, suggests that D. littoralis is more closely related to species of the virilis phylad than to species of the montana phylad, which is in contrast with the traditional view. Nevertheless, the phylogenetic analyses here performed using a 7 gene dataset suggest that D. littoralis is indeed more closely related to species of the virilis phylad than to species of the montana phylad. The re-evaluation of the phylogenetic relationship of the species of the virilis group, under the assumption of a relaxed molecular clock, results in an estimated age of the bilbo-like element insertion of at least 7.5 Mya.
Collapse
Affiliation(s)
- Micael Reis
- Instituto de Biologia Celular e Molecular (IBMC), University of Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
| | | | | | | |
Collapse
|
20
|
YASSIN AMIR, CAPY PIERRE, MADI-RAVAZZI LILIAN, OGEREAU DAVID, DAVID JEANR. DNA barcode discovers two cryptic species and two geographical radiations in the invasive drosophilid Zaprionus indianus. Mol Ecol Resour 2008; 8:491-501. [DOI: 10.1111/j.1471-8286.2007.02020.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
21
|
Mirol PM, Routtu J, Hoikkala A, Butlin RK. Signals of demographic expansion in Drosophila virilis. BMC Evol Biol 2008; 8:59. [PMID: 18298823 PMCID: PMC2276204 DOI: 10.1186/1471-2148-8-59] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Accepted: 02/25/2008] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The pattern of genetic variation within and among populations of a species is strongly affected by its phylogeographic history. Analyses based on putatively neutral markers provide data from which past events, such as population expansions and colonizations, can be inferred. Drosophila virilis is a cosmopolitan species belonging to the virilis group, where divergence times between different phylads go back to the early Miocene. We analysed mitochondrial DNA sequence variation among 35 Drosophila virilis strains covering the species' range in order to detect demographic events that could be used to understand the present characteristics of the species, as well as its differences from other members of the group. RESULTS Drosophila virilis showed very low nucleotide diversity with haplotypes distributed in a star-like network, consistent with a recent world-wide exponential expansion possibly associated either with domestication or post-glacial colonization. All analyses point towards a rapid population expansion. Coalescence models support this interpretation. The central haplotype in the network, which could be interpreted as ancestral, is widely distributed and gives no information about the geographical origin of the population expansion. The species showed no geographic structure in the distribution of mitochondrial haplotypes, in contrast to results of a recent microsatellite-based analysis. CONCLUSION The lack of geographic structure and the star-like topology depicted by the D. virilis haplotypes indicate a pattern of global demographic expansion, probably related to human movements, although this interpretation cannot be distinguished from a selective sweep in the mitochondrial DNA until nuclear sequence data become available. The particular behavioural traits of this species, including weak species-discrimination and intraspecific mate choice exercised by the females, can be understood from this perspective.
Collapse
Affiliation(s)
- Patricia M Mirol
- School of Biology, The University of Leeds, Leeds LS2 9JT, UK
- Museo Argentino de Ciencias Naturales, CONICET, Angel Gallardo 470, C1405DJR, Buenos Aires, Argentina
| | - Jarkko Routtu
- Department of Biological and Environmental Science, P.O. Box 35, 40014 University of Jyväskylä, Finland
| | - Anneli Hoikkala
- Department of Biological and Environmental Science, P.O. Box 35, 40014 University of Jyväskylä, Finland
| | - Roger K Butlin
- Animal and Plant Sciences, The University of Sheffield, Sheffield S10 2TN, UK
| |
Collapse
|
22
|
Routtu J, Hoikkala A, Kankare M. Microsatellite-based species identification method for Drosophila virilis group species. Hereditas 2007; 144:213-21. [PMID: 18031356 DOI: 10.1111/j.2007.0018-0661.02021.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Species of the D. virilis group are widely used in evolutionary research, but the individuals of different species are difficult to distinguish from each other morphologically. We constructed a fast and easy microsatellite-based identification method for the species of the group occurring sympatrically in northern Europe. The neighbor joining tree based on 14 microsatellite loci also gave a good resolution of the species divergence pattern in the whole group.
Collapse
Affiliation(s)
- Jarkko Routtu
- Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | | | | |
Collapse
|
23
|
Variation in Male Courtship Song Traits in Drosophila virilis: The Effects of Selection and Drift on Song Divergence at the Intraspecific Level. Behav Genet 2007; 38:82-92. [DOI: 10.1007/s10519-007-9173-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Accepted: 10/04/2007] [Indexed: 10/22/2022]
|
24
|
Routtu J, Mazzi D, Van der Linde K, Mirol P, Butlin RK, Hoikkala A. The extent of variation in male song, wing and genital characters among allopatric Drosophila montana populations. J Evol Biol 2007; 20:1591-601. [PMID: 17584251 DOI: 10.1111/j.1420-9101.2007.01323.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Drosophila montana, a species of the Drosophila virilis group, has distributed around the northern hemisphere. Phylogeographic analyses of two North American and one Eurasian population of this species offer a good background for the studies on the extent of variation in phenotypic traits between populations as well as for tracing the selection pressures likely to play a role in character divergence. In the present paper, we studied variation in the male courtship song, wing and genital characters among flies from Colorado (USA), Vancouver (Canada) and Oulanka (Finland) populations. The phenotypic divergence among populations did not coincide with the extent of their genetic divergence, suggesting that the characters are not evolving neutrally. Divergence in phenotypic traits was especially high between the Colorado and Vancouver populations, which are closer to each other in terms of their mtDNA genotypes than they are to the Oulanka population. The males of the Colorado population showed high divergence especially in song traits and the males of the Vancouver population in wing characters. Among the male song traits, two characters known to be under sexual selection and a trait important in species recognition differed clearly between populations, implying a history of directional and/or diversifying rather than balancing selection. The population divergence in wing characters is likely to have been enhanced by natural selection associated with environmental factors, whereas the male genitalia traits may have been influenced by sexual selection and/or sexual conflict.
Collapse
Affiliation(s)
- J Routtu
- Department of Biological and Environmental Sciences, University of Jyväskylä, Jyväskylä, Finland.
| | | | | | | | | | | |
Collapse
|
25
|
Klappert K, Mazzi D, Hoikkala A, Ritchie MG. MALE COURTSHIP SONG AND FEMALE PREFERENCE VARIATION BETWEEN PHYLOGEOGRAPHICALLY DISTINCT POPULATIONS OF DROSOPHILA MONTANA. Evolution 2007; 61:1481-8. [PMID: 17542854 DOI: 10.1111/j.1558-5646.2007.00125.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding the variation within and between populations in important male mating traits and female preferences is crucial to theories concerning the origin of sexual isolation by coevolution or other processes. There have been surprisingly few studies on the extent of variation and covariation within and between populations, especially where the evolutionary relationships between populations are understood. Here we examine variation in female preferences and a sexually selected male song trait, the carrier frequency of the song, within and between populations from different phylogeographic clusters of Drosophila montana. Song is obligatory for successful mating in this species, and both playback and field studies implicate song carrier frequency as the most important parameter in male song. Carrier frequency varied among three recently collected populations from Oulanka (Finland), Vancouver (Canada), and Colorado (central United States), which represent the main phylogeographic groups in D. montana. Males from Colorado had the most distinct song frequency, which did not follow patterns of genetic differentiation. There was considerable variation in preference functions within, and some variation between, populations. Surprisingly, females from three lines from Colorado seem to have preferences disfavoring the extreme male trait found in this population. We discuss sources of selection on male song and female preference.
Collapse
Affiliation(s)
- Kirsten Klappert
- Swiss Federal Institute for Environmental Science and Technology/Swiss Federal Institute of Technology, Aquatic Ecology, Uberlandstrasse 133, Dübendorf, Switzerland.
| | | | | | | |
Collapse
|