scholarly journals Evidence for Initiation of Post-Zygotic Reproductive Isolation between Drosophila ananassae and D. pallidosa as Indicated by Reduction in the Fertility of Hybrid Males

2020 ◽  
Vol 12 (2) ◽  
pp. 41
Author(s):  
Roshni Singh ◽  
Bashisth Narayan Singh
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sibling Species ◽  
Hybrid Sterility ◽  
Divergence Time ◽  
Sexual Isolation ◽  
Drosophila Ananassae ◽  
Species Pair ◽  
Hybrid Fertility ◽  
Species Pairs

There are several barriers to preclude the gene flow between diverging populations. On the basis of their temporal nature, these can be broadly categorized into two forms: pre- and post-zygotic. Post-zygotic reproductive isolation can manifest in the form of reductions in hybrid fertility. Keeping this fact in view, in the present study, we studied sterility in hybrids of D. ananassae and D. pallidosa. Surprisingly a distinguishable pattern of infertility was found in the hybrids. This pattern, referred to as Haldane’s rule, is often observed in hybrids of recently diverged populations or species. Reduction in the fertility of hybrids provides the clue of incipient kind of post-zygotic reproductive isolation in these two sibling species. This is the first report of hybrid sterility in this species pair. However, hybrid sterility is not very prominent especially when compared to that of other species pairs with the similar divergence time. Thus, on the basis of our results, we conclude that either sexual isolation between these sibling species is sufficient and does not require the aid of post-zygotic isolation to preclude gene flow or rate of divergence between D. ananassae and D. pallidosa is very slow in comparison to other species pair or even races of some species.

scholarly journals Loss of sexual isolation in a hybridizing stickleback species pair

2013 ◽  
Vol 59 (5) ◽  
pp. 591-603 ◽  
Author(s):  
Alycia C. R. Lackey ◽  
Janette Wenrick Boughman
Keyword(s):  
Reproductive Isolation ◽  
Sexual Isolation ◽  
Distinct Species ◽  
Mate Preferences ◽  
Reproductive Barriers ◽  
Species Pair ◽  
Hybrid Swarm ◽  
Species Formation ◽  
Species Pairs

Abstract One approach to understand the importance of reproductive barriers to the speciation process is to study the breakdown of barriers between formerly distinct species. One reproductive barrier, sexual isolation, reduces gene flow between species through differences in mate preferences and mating signals and is likely important for species formation and maintenance. We measure sexual isolation in two limnetic-benthic threespine stickleback species pairs (Gasterosteus spp.). One species pair maintains strong reproductive isolation while the other species pair has recently collapsed into a hybrid swarm. We compare the strength of sexual isolation in the hybridizing pair to the currently isolated pair. We provide the first evidence that sexual isolation has been lost in the hybridizing pair and show furthermore that preferences females have for conspecific mates and the traits they use to distinguish conspecific and heterospecific males contribute to this loss. This work highlights the fragility of reproductive isolation between young species pairs and considers the role of sexual isolation in speciation.

scholarly journals Studies on Mating Preference and Productivity in Drosophila ananassae and D. pallidosa and Their Hybrids

2020 ◽  
Vol 12 (2) ◽  
pp. 52
Author(s):  
Roshni Singh ◽  
Bashisth Narayan Singh
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sibling Species ◽  
Mating Preference ◽  
Drosophila Ananassae ◽  
Reproductive Barriers ◽  
Premating Isolation ◽  
Cosmopolitan Species ◽  
Viable Offspring

During speciation different kinds of reproductive barriers originate to preclude gene flow between diverging populations. Reproductive isolation or barriers to gene flow can be categorized by the temporal nature of their effect: pre-zygotic barriers occur before fertilization and post-zygotic barriers occur after fertilization. In this study, we studied each components of reproductive isolation between D. ananassae and D. pallidosa, including both pre-zygotic and post-zygotic barriers. Because it might be possible that by dissecting these barriers one can get the answers of many unresolved questions related to the process of speciation of these two sibling species. We reported premating isolation because females of both D. ananassae and D. pallidosa were more discriminative for mating against the alien males rather than conspecific males, and this discrimination was much stronger in case of D. ananassae females for being the ancestral and cosmopolitan species. We also did not find any decrease in the production of progeny or viable offspring in comparison to conspecific males, indicating a lack of postmating prezygotic isolating barriers. Further, there is no complete lack of intrinsic post-zygotic isolation between these species or not complete presence of post-zygotic isolation, as both the hybrid sons were producing less number of progeny in comparison to all the crosses but it is near to significant but not significant and this is contrasting to the results of a previous study.

scholarly journals Sexual isolation with and without ecological isolation in marine isopods J. albifrons and J. praehirsuta

2018 ◽  
Author(s):  
Ambre Ribardière ◽  
Elsa Pabion ◽  
Jérôme Coudret ◽  
Claire Daguin-Thiébaut ◽  
Céline Houbin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Free Choice ◽  
First Generation ◽  
Sexual Isolation ◽  
Relative Strength ◽  
Experimental Population ◽  
Species Pair ◽  
Ecological Isolation

AbstractSexual barriers associated with mate choice are nearly always found to be associated with some level of ecological isolation between species. The independence and relative strength of sexual isolation are thus difficult to assess. Here we take advantage of a pair of isopod species (Jaera albifrons and J. praehirsuta) that show sexual isolation and coexist in populations where they share the same microhabitat or not (i.e. without or with ecological isolation). Using no-choice trials and a free-choice experimental population, we estimated the strength of sexual isolation between J. albifrons and J. praehirsuta individuals originating from these different ecological contexts. We found that sexual isolation is strong in presence and absence of ecological isolation, but that it is asymmetric and fails to prevent gene flow entirely. First-generation post-zygotic barriers were low, and there was no sexual isolation within J. praehirsuta across habitats. The J. albifrons / J. praehirsuta species pair thus provides an example where the role of sexual isolation as a barrier to gene flow i) does not depend upon current ecological isolation, ii) seems to have evolved independently of local ecological conditions, but iii) is insufficient to complete speciation entirely on its own.

Symmetrical and asymmetrical sexual isolation among laboratory strains of Drosophila ananassae

1985 ◽  
Vol 27 (4) ◽  
pp. 405-409 ◽  
Author(s):  
Bashisth N. Singh ◽  
Sujata Chatterjee
Keyword(s):  
Sexual Selection ◽  
Reproductive Isolation ◽  
Assortative Mating ◽  
Sexual Isolation ◽  
Drosophila Ananassae ◽  
Isofemale Lines ◽  
Male Choice ◽  
Positive Assortative Mating ◽  
Different Strains ◽  
Assortive Mating

Male-choice experiments using five isofemale lines of Drosophila ananassae originating from different localities were performed to study sexual isolation within the species. In most of the crosses homogamic matings outnumber heterogamic ones, and deviation from randomness is statistically significant in 11 of 20 crosses. This provides evidence for positive assortative mating within D. ananassae. Isolation indices range from −0.057 to 0.555. Eleven positive isolation indices are significantly greater than zero. Both types of sexual isolation, symmetrical and asymmetrical, have been observed among different strains. Thus the present results clearly indicate that the laboratory strains of D. ananassae have developed behavioural reproductive isolation as a result of genetic divergence.Key words: Drosophila, assortive mating, sexual selection, behaviour.

THE GENETIC ARCHITECTURE OF REPRODUCTIVE ISOLATION DURING SPECIATION-WITH-GENE-FLOW IN LAKE WHITEFISH SPECIES PAIRS ASSESSED BY RAD SEQUENCING

Evolution ◽  
2013 ◽  
Vol 67 (9) ◽  
pp. 2483-2497 ◽  
Author(s):  
Pierre-Alexandre Gagnaire ◽  
Scott A. Pavey ◽  
Eric Normandeau ◽  
Louis Bernatchez
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Genetic Architecture ◽  
Rad Sequencing ◽  
Lake Whitefish ◽  
Species Pairs

scholarly journals What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies

2017 ◽  
Vol 284 (1856) ◽  
pp. 20170335 ◽  
Author(s):  
C. Mérot ◽  
C. Salazar ◽  
R. M. Merrill ◽  
C. D. Jiggins ◽  
M. Joron
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Reproductive Isolation ◽  
Hybrid Sterility ◽  
Wing Pattern ◽  
Key Factor ◽  
Comparative Results ◽  
Phylogenetic Divergence ◽  
The Continuum

The process by which species evolve can be illuminated by investigating barriers that limit gene flow between taxa. Recent radiations, such as Heliconius butterflies, offer the opportunity to compare isolation between pairs of taxa at different stages of ecological, geographical, and phylogenetic divergence. Here, we report a comparative analysis of existing and novel data in order to quantify the strength and direction of isolating barriers within a well-studied clade of Heliconius . Our results highlight that increased divergence is associated with the accumulation of stronger and more numerous barriers to gene flow. Wing pattern is both under natural selection for Müllerian mimicry and involved in mate choice, and therefore underlies several isolating barriers. However, pairs which share a similar wing pattern also display strong reproductive isolation mediated by traits other than wing pattern. This suggests that, while wing pattern is a key factor for early stages of divergence, it may become facultative at later stages of divergence. Additional factors including habitat partitioning, hybrid sterility, and chemically mediated mate choice are associated with complete speciation. Therefore, although most previous work has emphasized the role of wing pattern, our comparative results highlight that speciation is a multi-dimensional process, whose completion is stabilized by many factors.

scholarly journals Genetic architecture of a key reproductive isolation trait differs between sympatric and non-sympatric sister species of Lake Victoria cichlids

2020 ◽  
Vol 287 (1924) ◽  
pp. 20200270
Author(s):  
Anna F. Feller ◽  
Marcel P. Haesler ◽  
Catherine L. Peichel ◽  
Ole Seehausen
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Related Species ◽  
Genetic Architecture ◽  
Lake Victoria ◽  
Sympatric Species ◽  
Sister Species ◽  
Species Pair ◽  
Closely Related Species ◽  
Nuptial Coloration

One hallmark of the East African cichlid radiations is the rapid evolution of reproductive isolation that is robust to full sympatry of many closely related species. Theory predicts that species persistence and speciation in sympatry with gene flow are facilitated if loci of large effect or physical linkage (or pleiotropy) underlie traits involved in reproductive isolation. Here, we investigate the genetic architecture of a key trait involved in behavioural isolation, male nuptial coloration, by crossing two sister species pairs of Lake Victoria cichlids of the genus Pundamilia and mapping nuptial coloration in the F2 hybrids. One is a young sympatric species pair, representative of an axis of colour motif differentiation, red-dorsum versus blue, that is highly recurrent in closely related sympatric species. The other is a species pair representative of colour motifs, red-chest versus blue, that are common in allopatric but uncommon in sympatric closely related species. We find significant quantitative trait loci (QTLs) with moderate to large effects (some overlapping) for red and yellow in the sympatric red-dorsum × blue cross, whereas we find no significant QTLs in the non-sympatric red-chest × blue cross. These findings are consistent with theory predicting that large effect loci or linkage/pleiotropy underlying mating trait differentiation could facilitate speciation and species persistence with gene flow in sympatry.

scholarly journals The importance of intrinsic postzygotic barriers throughout the speciation process

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190533 ◽  
Author(s):  
Jenn M. Coughlan ◽  
Daniel R. Matute
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Rapid Evolution ◽  
Theoretical Work ◽  
Sympatric Species ◽  
Species Boundaries ◽  
Biological Models ◽  
Speciation Process ◽  
Species Pairs ◽  
Postzygotic Barriers

Intrinsic postzygotic barriers can play an important and multifaceted role in speciation, but their contribution is often thought to be reserved to the final stages of the speciation process. Here, we review how intrinsic postzygotic barriers can contribute to speciation, and how this role may change through time. We outline three major contributions of intrinsic postzygotic barriers to speciation. (i) reduction of gene flow : intrinsic postzygotic barriers can effectively reduce gene exchange between sympatric species pairs. We discuss the factors that influence how effective incompatibilities are in limiting gene flow. (ii) early onset of species boundaries via rapid evolution : intrinsic postzygotic barriers can evolve between recently diverged populations or incipient species, thereby influencing speciation relatively early in the process. We discuss why the early origination of incompatibilities is expected under some biological models, and detail how other (and often less obvious) incompatibilities may also serve as important barriers early on in speciation. (iii) reinforcement : intrinsic postzygotic barriers can promote the evolution of subsequent reproductive isolation through processes such as reinforcement, even between relatively recently diverged species pairs. We incorporate classic and recent empirical and theoretical work to explore these three facets of intrinsic postzygotic barriers, and provide our thoughts on recent challenges and areas in the field in which progress can be made. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.

Ecology and evolution of sympatric sticklebacks (Gasterosteus): morphological and genetic evidence for a species pair in Enos Lake, British Columbia

1984 ◽  
Vol 62 (7) ◽  
pp. 1402-1408 ◽  
Author(s):  
J. D. McPhail
Keyword(s):  
Gene Flow ◽  
Body Shape ◽  
Gasterosteus Aculeatus ◽  
Biological Species ◽  
Similar Species ◽  
Species Pair ◽  
Strait Of Georgia ◽  
Biochemical Characteristics ◽  
Species Pairs ◽  
Gill Raker

Two morphological forms of three-spined stickleback (Gasterosteus) coexist in Enos Lake near Nanoose Bay, Vancouver Island. For convenience, the two forms are referred to as "benthics" and "limnetics." Morphological and biochemical characteristics of the two forms were examined and artificial hybrids (F1 and F2) reared in the laboratory. The two forms differ in male nuptial colour, body shape, and gill raker architecture. These differences are inherited and have remained stable for several generations. Benthics and limnetics also differ in allele frequencies at three loci (Mdh-3, Ck, and Pgm). At one of these loci (Mdh-3) the limnetic form is polymorphic and the benthic form is fixed. Since the two forms maintain themselves as discrete entities and there is no evidence of gene flow, they are considered separate biological species. It is not certain that either of these species is Gasterosteus aculeatus. Similar species pairs exist in other lakes in the Strait of Georgia region but, at present, their relationship to the species pair in Enos Lake is unknown.

scholarly journals What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies

2017 ◽  
Author(s):  
C. Mérot ◽  
C. Salazar ◽  
R. M. Merrill ◽  
C. Jiggins ◽  
M. Joron
Keyword(s):  
Gene Flow ◽  
Mate Choice ◽  
Reproductive Isolation ◽  
Hybrid Sterility ◽  
Habitat Isolation ◽  
Wing Pattern ◽  
Key Factor ◽  
Comparative Results ◽  
Phylogenetic Divergence

AbstractThe process by which species evolve can be illuminated by investigating barriers that limit gene flow between taxa. Recent radiations, such as Heliconius butterflies, offer the opportunity to compare isolation between pairs of taxa at different stages of ecological, geographic and phylogenetic divergence. We carry out a comparative analysis of existing and novel data in order to quantify the strength and direction of isolating barriers within a well-studied clade of Heliconius. Our results highlight that increased divergence is associated with the accumulation of stronger and more numerous barriers to gene flow. Wing pattern is both under natural selection for Müllerian mimicry and involved in mate choice, and therefore underlies several isolating barriers. However, pairs which share a similar wing pattern, also display strong reproductive isolation mediated by traits other than wing pattern. This suggests that, while wing pattern is a key factor for early stages of divergence, it is not essential at a higher level. Additional factors including habitat isolation, hybrid sterility and chemically-mediated mate choice are associated with complete speciation. Therefore, although most previous work has emphasised the role of wing pattern, our comparative results highlight that speciation is a multidimensional process, whose completion is stabilized by many factors.

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