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1.
PLoS Genet ; 20(9): e1011396, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39241096

RESUMEN

Species delineation in microorganisms is challenging due to the limited markers available for accurate species assignment. Here, we applied an integrative taxonomy approach, combining extensive sampling, whole-genome sequence-based classification, phenotypic profiling, and assessment of interspecific reproductive isolation. Our work reveals the presence of a distinct Saccharomyces lineage in Nothofagus forests of coastal Patagonia. This lineage, designated Saccharomyces chiloensis sp. nov., exhibits 7% genetic divergence from its sister species S. uvarum, as revealed by whole-genome sequencing and population analyses. The South America-C (SA-C) coastal Patagonia population forms a unique clade closely related to a previously described divergent S. uvarum population from Oceania (AUS, found in Australia and New Zealand). Our species reclassification is supported by a low Ortho Average Nucleotide Identity (OANI) of 93% in SA-C and AUS relative to S. uvarum, which falls below the suggested species delineation threshold of 95%, indicating an independent evolutionary lineage. Hybrid spore viability assessment provided compelling evidence that SA-C and AUS are reproductively isolated from S. uvarum. In addition, we found unique structural variants between S. chiloensis sp. nov. lineages, including large-scale chromosomal translocations and inversions, together with a distinct phenotypic profile, emphasizing their intraspecies genetic distinctiveness. We suggest that S. chiloensis sp. nov diverged from S. uvarum in allopatry due to glaciation, followed by post-glacial dispersal, resulting in distinct lineages on opposite sides of the Pacific Ocean. The discovery of S. chiloensis sp. nov. illustrates the uniqueness of Patagonia's coastal biodiversity and underscores the importance of adopting an integrative taxonomic approach in species delineation to unveil cryptic microbial species. The holotype of S. chiloensis sp. nov. is CBS 18620T.


Asunto(s)
Filogenia , Saccharomyces , Saccharomyces/genética , Saccharomyces/clasificación , Secuenciación Completa del Genoma , Aislamiento Reproductivo
2.
Mol Biol Evol ; 41(9)2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39150953

RESUMEN

The relative importance of genetic drift and local adaptation in facilitating speciation remains unclear. This is particularly true for seabirds, which can disperse over large geographic distances, providing opportunities for intermittent gene flow among distant colonies that span the temperature and salinity gradients of the oceans. Here, we delve into the genomic basis of adaptation and speciation of banded penguins, Galápagos (Spheniscus mendiculus), Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), and African penguins (Spheniscus demersus), by analyzing 114 genomes from the main 16 breeding colonies. We aim to identify the molecular mechanism and genomic adaptive traits that have facilitated their diversifications. Through positive selection and gene family expansion analyses, we identified candidate genes that may be related to reproductive isolation processes mediated by ecological thermal niche divergence. We recover signals of positive selection on key loci associated with spermatogenesis, especially during the recent peripatric divergence of the Galápagos penguin from the Humboldt penguin. High temperatures in tropical habitats may have favored selection on loci associated with spermatogenesis to maintain sperm viability, leading to reproductive isolation among young species. Our results suggest that genome-wide selection on loci associated with molecular pathways that underpin thermoregulation, osmoregulation, hypoxia, and social behavior appears to have been crucial in local adaptation of banded penguins. Overall, these results contribute to our understanding of how the complexity of biotic, but especially abiotic, factors, along with the high dispersal capabilities of these marine species, may promote both neutral and adaptive lineage divergence even in the presence of gene flow.


Asunto(s)
Selección Genética , Spheniscidae , Animales , Spheniscidae/genética , Genómica , Especiación Genética , Flujo Génico , Genoma , Aislamiento Reproductivo
3.
Sci Rep ; 14(1): 19803, 2024 08 27.
Artículo en Inglés | MEDLINE | ID: mdl-39191906

RESUMEN

To explain how populations with distinct warning signals coexist in close parapatry, we experimentally assessed intrinsic mechanisms acting as reproductive barriers within three poison-frog species from the Peruvian Amazon belonging to a Müllerian mimetic ring (Ranitomeya variabilis, Ranitomeya imitator and Ranitomeya fantastica). We tested the role of prezygotic and postzygotic isolation barriers between phenotypically different ecotypes of each species, using no-choice mating experiments and offspring survival analysis. Our results show that prezygotic mating preference did not occur except for one specific ecotype of R. imitator, and that all three species were able to produce viable inter-population F1 hybrids. However, while R. variabilis and R. imitator hybrids were able to produce viable F2 generations, we found that for R. fantastica, every F1 hybrid males were sterile while females remained fertile. This unexpected result, echoing with Haldane's rule of speciation, validated phylogenetic studies which tentatively diagnose these populations of R. fantastica as two different species. Our work suggests that postzygotic genetic barriers likely participate in the extraordinary phenotypic diversity observed within Müllerian mimetic Ranitomeya populations, by maintaining species boundaries.


Asunto(s)
Especiación Genética , Aislamiento Reproductivo , Animales , Femenino , Masculino , Perú , Anuros/genética , Anuros/fisiología , Filogenia , Reproducción , Fenotipo , Ranas Venenosas
4.
J Plant Res ; 137(5): 863-875, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38982014

RESUMEN

Reproductive isolation is one of the mechanisms of speciation. The two currently accepted subspecies of Parodia haselbergii (P. haselbergii subsp. haselbergii and P. haselbergii subsp. graessneri) were studied regarding flower traits, phenology, breeding systems and pollination. In addition, a principal component analysis with 18 floral characters and germination tests under controlled conditions were performed for both taxa. Pollination was studied in the field, in two localities of Southern Brazil. Pollinators were recorded through photos and film. Breeding system experiments were performed by applying controlled pollinations to plants excluded from pollinators. Both taxa mostly differ in asynchronous flowering periods, floral traits (including floral part measurements and nectar concentration) and pollinators. The flowers of both subspecies are functionally protogynous and perform remarkably long lifespans (≥ 15 days), both traits being novelties for Cactaceae. Whereas the reddish flowers of P. haselbergii subsp. haselbergii (nectar concentration: ca. 18%) are pollinated by hummingbirds of Thalurania glaucopis, the greenish flowers of P. haselbergii subsp. graessneri (nectar concentration: ca. 29%) are pollinated by Augochlora bees (Halictidae). Both subspecies are self-compatible, yet pollinator-dependent. The principal component analysis evidenced that both subspecies are separated, regarding flower traits. The seeds of both subspecies performed differently in the germination tests, but the best results were recovered at 20 °C and germination considerably decreased around 30 °C. In conclusion, all these results support that both taxa are in reproductive isolation, and can be treated as different species.


Asunto(s)
Cactaceae , Flores , Polinización , Flores/fisiología , Flores/anatomía & histología , Flores/crecimiento & desarrollo , Polinización/fisiología , Cactaceae/fisiología , Brasil , Animales , Germinación/fisiología , Aislamiento Reproductivo , Reproducción/fisiología , Especificidad de la Especie , Análisis de Componente Principal , Néctar de las Plantas , Aves/fisiología
5.
G3 (Bethesda) ; 14(7)2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38718200

RESUMEN

During the last decade, the spotted wing drosophila, Drosophila suzukii, has spread from eastern Asia to the Americas, Europe, and Africa. This fly attacks many species of cultivated and wild fruits with soft, thin skins, where its serrated ovipositor allows it to lay eggs in undamaged fruit. Parasitoids from the native range of D. suzukii may provide sustainable management of this polyphagous pest. Among these parasitoids, host-specificity testing has revealed a lineage of Ganaspis near brasiliensis, referred to in this paper as G1, that appears to be a cryptic species more host-specific to D. suzukii than other parasitoids. Differentiation among cryptic species is critical for introduction and subsequent evaluation of their impact on D. suzukii. Here, we present results on divergence in genomic sequences and architecture and reproductive isolation between lineages of Ganaspis near brasiliensis that appear to be cryptic species. We studied five populations, two from China, two from Japan, and one from Canada, identified as the G1 vs G3 lineages based on differences in cytochrome oxidase l sequences. We assembled and annotated the genomes of these populations and analyzed divergences in sequence and genome architecture between them. We also report results from crosses to test reproductive compatibility between the G3 lineage from China and the G1 lineage from Japan. The combined results on sequence divergence, differences in genome architectures, ortholog divergence, reproductive incompatibility, differences in host ranges and microhabitat preferences, and differences in morphology show that these lineages are different species. Thus, the decision to evaluate the lineages separately and only import and introduce the more host-specific lineage to North America and Europe was appropriate.


Asunto(s)
Drosophila , Animales , Drosophila/genética , Genoma de los Insectos , Reproducción/genética , Aislamiento Reproductivo , Filogenia , Femenino , Variación Genética , Genómica/métodos
6.
An Acad Bras Cienc ; 96(1): e20221011, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38597487

RESUMEN

Groupers (Epinephelidae and Serranidae) have attracted special attention to fish farming, and their species offer good opportunities for successful hybridizations. Cytogenetic data allow a better understanding of the role of karyotypic diversification in the acquisition of post-zygotic reproductive isolation (RI). Thus, chromosomal analyses were performed on E. striatus (Caribbean Sea), E. coioides and E. tauvina (Indo-Pacific Region), using standard procedures and mapping of six repetitive DNA classes by the in situ hybridization. The three species have 2n=48 chromosomes. The karyotypes of E. coioides and E. striatus are composed only of acrocentric chromosomes (FN=48), while E. tauvina has 8 submetacentric chromosomes (FN=56). Heterochromatin has a preferential centromeric distribution, and the microsatellite repeats are dispersed throughout the chromosomes of all species. The 18S and 5S rDNA sites are unique but show a colocalization arrangement in E. tauvina and E. striatus. The chromosomal organization suggests that the three species still maintain a significant amount of syntenic regions. The range of the karyotype divergence and the RI levels showed low, but goes turn proportionally greater in relation to the divergence time between the parental species. The slow acquisition of postzygotic RI is consistent with the high karyotype homogeneity presented by Epinephelidae family.


Asunto(s)
Lubina , Perciformes , Animales , Lubina/genética , Aislamiento Reproductivo , Cariotipo , Cariotipificación
7.
Evolution ; 78(6): 1161-1173, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38530643

RESUMEN

Incomplete speciation can be leveraged to associate phenotypes with genotypes, thus providing insights into the traits relevant to the reproductive isolation of diverging taxa. We investigate the genetic underpinnings of the phenotypic differences between Sporophila plumbea and Sporophila beltoni. Sporophila beltoni has only recently been described based, most notably, based on differences in bill coloration (yellow vs. black in S. plumbea). Both species are indistinguishable through mtDNA or reduced-representation genomic data, and even whole-genome sequencing revealed low genetic differentiation. Demographic reconstructions attribute this genetic homogeneity to gene flow, despite divergence in the order of millions of generations. We found a narrow hybrid zone in southern Brazil where genetically, yet not phenotypically, admixed individuals appear to be prevalent. Despite the overall low genetic differentiation, we identified 3 narrow peaks along the genome with highly differentiated SNPs. These regions harbor 6 genes, one of which is involved in pigmentation (EDN3) and is a candidate for controlling bill color. Within the outlier peaks, we found signatures of resistance to gene flow, as expected for islands of speciation. Our study shows how genes related to coloration traits are likely involved in generating prezygotic isolation and establishing species boundaries early in speciation.


Asunto(s)
Flujo Génico , Especiación Genética , Pigmentación , Pigmentación/genética , Brasil , Islas Genómicas , Animales , Aislamiento Reproductivo , Fenotipo , Polimorfismo de Nucleótido Simple
8.
Mol Phylogenet Evol ; 193: 108013, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38195012

RESUMEN

The speciation continuum is the process by which genetic groups diverge until they reach reproductive isolation. It has become common in the literature to show that this process is gradual and flickering, with possibly many instances of secondary contact and introgression after divergence has started. The level of divergence might vary among genomic regions due to, among others, the different forces and roles of selection played by the shared regions. Through hybrid capture, we sequenced ca. 4,000 nuclear regions in populations of six species of wax palms, five of which form a monophyletic group (genus Ceroxylon, Arecaceae: Ceroxyloideae). We show that in this group, the different populations show varying degrees of introgressive hybridization, and two of them are backcrosses of the other three 'pure' species. This is particularly interesting because these three species are dioecious, have a shared main pollinator, and have slightly overlapping reproductive seasons but highly divergent morphologies. Our work supports shows wax palms diverge under positive and background selection in allopatry, and hybridize due to secondary contact and inefficient reproductive barriers, which sustain genetic diversity. Introgressed regions are generally not under positive selection. Peripheral populations are backcrosses of other species; thus, introgressive hybridization is likely modulated by demographic effects rather than selective pressures. In general, these species might function as an 'evolutionary syngameon' where expanding, peripheral, small, and isolated populations maintain diversity by crossing with available individuals of other wax palms. In the Andean context, species can benefit from gained variation from a second taxon or the enhancement of population sizes by recreating a common genetic pool.


Asunto(s)
Arecaceae , Introgresión Genética , Humanos , Filogenia , Pool de Genes , Evolución Biológica , Aislamiento Reproductivo , Arecaceae/genética , Hibridación Genética , Flujo Génico , Especiación Genética
9.
J Plant Res ; 137(1): 65-77, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37991585

RESUMEN

Several barriers contribute to reproductive isolation between plant species, which can be classified as pre- or post-pollination. Understanding the strength of these barriers could clarify the factors that maintain reproductive isolation and thus species integrity. In this study, we quantified reproductive isolation between two bat-pollinated co-occurring Bauhinia species (B. acuruana and B. pentandra) with similar flower morphology. Over the course of 18 months, we assessed reproductive isolation between these two Bauhinia species by quantifying the individual strengths and absolute contributions of five pre- and post- pollination barriers. Our data showed that both species are completely isolated in their reproduction by a combination of several barriers. Although they co-occur in a few populations, we found a high degree of geographic isolation between them. And although their flowering periods overlap, there is a significant difference in flowering peaks. Both species have the same pollinating bats, but the interspecific transfer of pollen between the plant species may be reduced due to the different length of the flower stamens, resulting in different pollen deposition on the bats' bodies. We have documented complete incompatibility between taxa and conclude that pre- and post-pollination barriers are important factors in preventing gene flow, even in contact zones between these two species of Bauhinia. We highlight that our work is the first study to use methods to estimate the strength of reproductive isolation barriers between bat-pollinated species.


Asunto(s)
Bauhinia , Quirópteros , Fabaceae , Animales , Aislamiento Reproductivo , Polinización , Flores/anatomía & histología
10.
J Med Entomol ; 60(5): 998-1007, 2023 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-37459050

RESUMEN

Chagas disease is an important vector-borne disease endemic in Mexico. Of the 33 triatomine species found in Mexico, Triatoma longipennis (Usinger) is considered among the most important because of its infection indices, capacity for transmitting Trypanosoma cruzi (Chagas), and its distribution areas. Here, we describe the results of a reproductive isolation analysis among 5 populations of T. longipennis collected from representative areas of Mexico. Fertility and segregation of morphological characteristics were examined in two generations of hybrids. The percentage of pairs with (fertile) offspring varied from 30% to 100% in the parental crosses, while these values varied from 0 to 100% in the intersite crosses. Our results indicate partial reproductive isolation among these populations. These findings shed light on the potential presence of a cryptic species complex of T. longipennis in Mexico.


Asunto(s)
Enfermedad de Chagas , Triatoma , Triatominae , Trypanosoma cruzi , Animales , Triatoma/genética , Aislamiento Reproductivo , México/epidemiología
11.
J Evol Biol ; 36(8): 1077-1089, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37306282

RESUMEN

Contact zones provide important insights into the evolutionary processes that underlie lineage divergence and speciation. Here, we use a contact zone to ascertain speciation potential in the red-eyed treefrog (Agalychnis callidryas), a brightly coloured and polymorphic frog that exhibits unusually high levels of intraspecific variation. Populations of A. callidryas differ in a number of traits, several of which are known sexual signals that mediate premating reproductive isolation in allopatric populations. Along the Caribbean coast of Costa Rica, a ~100 km contact zone, situated between two phenotypically and genetically divergent parent populations, contains multiple colour pattern phenotypes and late-generation hybrids. This contact zone provides the opportunity to examine processes that are important in the earliest stages of lineage divergence. We performed analyses of colour pattern variation in five contact zone sites and six parental sites and found complex, continuous colour variation along the contact zone. We found discordance between the geographic distribution of colour pattern and previously described genomic population structure. We then used a parental site and contact zone site to measure assortative mating and directional selection from naturally-occurring amplectant mating pairs. We found assortative mating in a parental population, but no assortative mating in the contact zone. Furthermore, we uncovered evidence of directional preference towards the adjacent parental phenotype in the contact zone population, but no directional preference in the parent population. Combined, these data provide insights into potential dynamics at the contact zone borders and indicate that incipient speciation between parent populations will be slowed.


Asunto(s)
Preferencia en el Apareamiento Animal , Anuros , Animales , Costa Rica , Región del Caribe , Aislamiento Reproductivo
12.
Evolution ; 76(10): 2260-2271, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36036483

RESUMEN

Geographic isolation is a central mechanism of speciation, but perfect isolation of populations is rare. Although speciation can be hindered if gene flow is large, intermediate levels of migration can enhance speciation by introducing genetic novelty in the semi-isolated populations or founding small communities of migrants. Here, we consider a two-island neutral model of speciation with continuous migration and study diversity patterns as a function of the migration probability, population size, and number of genes involved in reproductive isolation (dubbed as genome size). For small genomes, low levels of migration induce speciation on the islands that otherwise would not occur. Diversity, however, drops sharply to a single species inhabiting both islands as the migration probability increases. For large genomes, sympatric speciation occurs even when the islands are strictly isolated. Then species richness per island increases with the probability of migration, but the total number of species decreases as they become cosmopolitan. For each genome size, there is an optimal migration intensity for each population size that maximizes the number of species. We discuss the observed modes of speciation induced by migration and how they increase species richness in the insular system while promoting asymmetry between the islands and hindering endemism.


Asunto(s)
Especiación Genética , Aislamiento Reproductivo , Densidad de Población , Islas , Filogenia
13.
Sci Rep ; 12(1): 10888, 2022 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-35764791

RESUMEN

Incomplete premating barriers in closely related species may result in reproductive interference. This process has different fitness consequences and can lead to three scenarios: niche segregation, sexual exclusion, or reproductive character displacement. In morphologically cryptic species, isolation barriers can be difficult to recognize. Here, we analyzed the morphological, behavioral, and genetic differences between two sympatric cryptic species of the genus Hetaerina to determine the characters that contribute the most to reproductive isolation and the effect of the high rates of behavior interference between the species. We found complete genetic isolation and significant differences in the morphometry of caudal appendages and wing shape, as well as body size variation between species. In contrast, we did not find clear differences in the coloration of the wing spot and observed high rates of interspecific aggression. Our results suggest that divergence in the shape of the caudal appendages is the principal pre-mating barrier that prevents interspecific mating. Moreover, a scenario of character displacement on body size was found. Nevertheless, size could play an important role in both inter- and intrasexual interactions and, therefore, we cannot differentiate if it has resulted from reproductive or aggressive interference.


Asunto(s)
Odonata , Aislamiento Reproductivo , Animales , Evolución Biológica , Especificidad de la Especie , Alas de Animales/anatomía & histología
14.
Mol Ecol ; 30(15): 3716-3729, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34087027

RESUMEN

Speciation proceeds through mechanisms that promote reproductive isolation and shape the extent of genetic variation in natural populations, and thus its study is essential to understand the evolutionary processes leading to increased biodiversity. Chromosomal rearrangements are known to facilitate reproductive isolation by hybrid sterility and favour speciation events. The genus Ipheion (Amaryllidaceae, Allioideae) is unique as its species exhibit a remarkable karyological variability but lack population-level genetic data. To unveil the diversification processes acting upon the formation of new lineages within Ipheion in the Pampas of South America, we combined morphology and karyology approaches with genotyping-by-sequencing. Our phylogenomic and population genomics results supported the taxonomic division of Ipheion into three morphological and genetically well-differentiated groups. The origin of Ipheion uniflorum was traced back to its current southern distribution area in the southern Pampean region (in Argentina), from where it had expanded to the north reaching Uruguay. Our results further suggested that chromosome rearrangements and ploidy shifts had triggered speciation events, first during the origin of I. uniflorum and later during its subsequent diversification into I. recurvifolium and I. tweedieanum, in both cases reinforced by extrinsic factors and biogeographical settings. The current study illustrates the analytical power of multidisciplinary approaches integrating phylo- and population genomics with classic analyses to reveal evolutionary processes in plants.


Asunto(s)
Ajo , Evolución Biológica , Especiación Genética , Genómica , Filogenia , Aislamiento Reproductivo
15.
Mol Ecol ; 30(16): 4062-4076, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34160853

RESUMEN

Understanding how geographic and environmental heterogeneity drive local patterns of genetic variation is a major goal of ecological genomics and a key question in evolutionary biology. The tropical Andes and inter-Andean valleys are shaped by markedly heterogeneous landscapes, where species experience strong selective processes. We examined genome-wide SNP data together with behavioural and ecological traits (mating calls and body size) known to contribute to genetic isolation in anurans in the banana tree-dwelling frog, Boana platanera, distributed across an environmental gradient in Central Colombia (northern South America). Here, we analysed the relationships between environmentally (temperature and precipitation) associated genetic and phenotypic differentiation and the potential drivers of isolation by environment along an elevation gradient. We identified candidate SNPs associated with temperature and body size, which follow a clinal pattern of genome-wide differentiation tightly coupled with phenotypic variation: as elevation increases, B. platanera exhibits larger body size and longer call duration with more pulses but lower pulse rate and frequency. Thus, the environmental landscape has rendered a scenario where isolation by environment and candidate loci show concordance with phenotypic divergence in this tropical frog along an elevation gradient in the Colombian Andes. Our study sets the basis for evaluating the role of temperature in the genetic structure and local adaptation in tropical treefrogs and its putative effect on life cycle (embryos, tadpoles, adults) along elevation gradients.


Asunto(s)
Altitud , Anuros , Animales , Anuros/genética , Colombia , Genómica , Aislamiento Reproductivo
16.
Evolution ; 75(9): 2251-2268, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34019308

RESUMEN

Hybridizing species provide a powerful system to identify the processes that shape genomic variation and maintain species boundaries. However, complex histories of isolation, gene flow, and selection often generate heterogeneous genomic landscapes of divergence that complicate reconstruction of the speciation history. Here, we explore patterns of divergence to reconstruct recent speciation in the erato clade of Heliconius butterflies. We focus on the genomic landscape of divergence across three contact zones of the species H. erato and H. himera. We show that these hybridizing species have an intermediate level of divergence in the erato clade, which fits with their incomplete levels of reproductive isolation. Using demographic modeling and the relationship between admixture and divergence with recombination rate variation, we reconstruct histories of gene flow, selection, and demographic change that explain the observed patterns of genomic divergence. We find that periods of isolation and selection within populations, followed by secondary contact with asymmetrical gene flow are key factors in shaping the heterogeneous genomic landscapes. Collectively, these results highlight the effectiveness of demographic modeling and recombination rate estimates to disentangling the distinct contributions of gene flow and selection to patterns of genomic divergence.


Asunto(s)
Mariposas Diurnas , Animales , Mariposas Diurnas/genética , Flujo Génico , Especiación Genética , Genoma , Aislamiento Reproductivo
17.
Sci Rep ; 11(1): 9844, 2021 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-33972659

RESUMEN

Interspecific hybridization is a stressful condition that can lead to sterility and/or inviability through improper gene regulation in Drosophila species with a high divergence time. However, the extent of these abnormalities in hybrids of recently diverging species is not well known. Some studies have shown that in Drosophila, the mechanisms of postzygotic isolation may evolve more rapidly in males than in females and that the degree of viability and sterility is associated with the genetic distance between species. Here, we used transcriptomic comparisons between two Drosophila mojavensis subspecies and D. arizonae (repleta group, Drosophila) and identified greater differential gene expression in testes than in ovaries. We tested the hypothesis that the severity of the interspecies hybrid phenotype is associated with the degree of gene misregulation. We showed limited gene misregulation in fertile females and an increase in the amount of misregulation in males with more severe sterile phenotypes (motile vs. amotile sperm). In addition, for these hybrids, we identified candidate genes that were mostly associated with spermatogenesis dysfunction.


Asunto(s)
Drosophila/fisiología , Hibridación Genética , Infertilidad Masculina/veterinaria , Espermatogénesis/genética , Testículo/patología , Animales , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Especiación Genética , Infertilidad Masculina/genética , Infertilidad Masculina/patología , Masculino , Ovario/patología , Aislamiento Reproductivo , Factores Sexuales , Motilidad Espermática/genética
18.
Science ; 371(6536)2021 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-33766854

RESUMEN

Behavioral isolation can catalyze speciation and permit the slow accumulation of additional reproductive barriers between co-occurring organisms. We illustrate how this process occurs by examining the genomic and behavioral bases of pre-mating isolation between two bird species (Sporophila hypoxantha and the recently discovered S. iberaensis) that belong to the southern capuchino seedeaters, a recent, rapid radiation characterized by variation in male plumage coloration and song. Although these two species co-occur without obvious ecological barriers to reproduction, we document behaviors indicating species recognition by song and plumage traits and strong assortative mating associated with genomic regions underlying male plumage patterning. Plumage differentiation likely originated through the reassembly of standing genetic variation, indicating how novel sexual signals may quickly arise and maintain species boundaries.


Asunto(s)
Especiación Genética , Preferencia en el Apareamiento Animal , Passeriformes/genética , Passeriformes/fisiología , Aislamiento Reproductivo , Animales , Argentina , Evolución Biológica , Femenino , Variación Genética , Genoma , Haplotipos , Masculino , Mutación , Pigmentación/genética , Simpatría , Vocalización Animal
19.
Evolution ; 74(11): 2541-2543, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33078392

RESUMEN

Mimicry can directly affect the evolutionary history of models, mimics, and signal receivers. Mimics often use multimodal signaling to deceive receivers. Jamie et al. showed that brood parasitic birds display multimodal signaling of mimetic traits triggered by sexual and filial imprinting on host species. These resulting adaptations can interact with premating isolation barriers to strengthen reproductive isolation and potentially drive sympatric speciation.


Asunto(s)
Pinzones , Radiación , Animales , Evolución Biológica , Aislamiento Reproductivo , Simpatría
20.
Zootaxa ; 4852(5): zootaxa.4852.5.8, 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-33056400

RESUMEN

Anuran calls are conspicuous, diverse and subject to sexual selection. Many types of calls are described, but the most commonly studied is the advertisement call (Wells 2007; Toledo et al. 2014). Advertisement calls in anurans are emitted by males and some females (Toledo et al. 2014), and have the function of attracting conspecific mates and repelling male competitors. Because the advertisement calls of many species differ by such a magnitude that they serve as premating species (Heyer et al. 1996), it has been demonstrated that advertisement calls play an important role in species recognition, reproductive isolation, and may reflect evolutionary relations among taxa (Wells 2007; Escalona et al. 2018).


Asunto(s)
Anuros , Vocalización Animal , Animales , Evolución Biológica , Colombia , Femenino , Masculino , Aislamiento Reproductivo
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