Rapid Evolution of Assortative Fertilization between Recently Allopatric Species of Drosophila

The virilis group of Drosophila represents a relatively unexplored but potentially useful model to investigate the genetics of speciation. Good resolution of phylogenetic relationships and the ability to obtain fertile hybrid offspring make the group especially promising for analysis of genetic changes underlying reproductive isolation separate from hybrid sterility and inviability. Phylogenetic analyses reveal a close relationship between the sister species, Drosophila americana and D. novamexicana, yet excepting their contemporary allopatric distributions, factors that contribute to reproductive isolation between this species pair remain uncharacterized. A previous report has shown reduced progeny numbers in laboratory crosses between the two species, especially when female D. novamexicana are crossed with male D. americana. We show that the hatch rate of eggs produced from heterospecific matings is reduced relative to conspecific matings. Failure of eggs to hatch, and consequent reduction in hybrid progeny number, is caused by low fertilization success of heterospecific sperm, thus representing a postmating, prezygotic incompatibility. Following insemination, storage and motility of heterospecific sperm is visibly compromised in female D. novamexicana. Our results provide evidence for a mechanism of reproductive isolation that is seldom reported for Drosophila species, and indicate the rapid evolution of postmating, prezygotic reproductive barriers in allopatry.

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The genetics of postzygotic isolation in the Drosophila virilis group.

Genetics ◽

10.1093/genetics/121.3.527 ◽

1989 ◽

Vol 121 (3) ◽

pp. 527-537 ◽

Cited By ~ 1

Author(s):

H A Orr ◽

J A Coyne

Keyword(s):

Reproductive Isolation ◽

X Chromosome ◽

Related Species ◽

Hybrid Sterility ◽

Drosophila Virilis ◽

Female Sterility ◽

Postzygotic Isolation ◽

Male And Female ◽

Virilis Group ◽

Drosophila Virilis Group

Abstract In a genetic study of postzygotic reproductive isolation among species of the Drosophila virilis group, we find that the X chromosome has the largest effect on male and female hybrid sterility and inviability. The X alone has a discernible effect on postzygotic isolation between closely related species. Hybridizations involving more distantly related species also show large X-effects, although the autosomes may also play a role. In the only hybridization yet subjected to such analysis, we show that hybrid male and female sterility result from the action of different X-linked loci. Our results accord with genetic studies of other taxa, and support the view that both Haldane's rule (heterogametic F1 sterility or inviability) and the large effect of the X chromosome on reproductive isolation result from the accumulation by natural selection of partially recessive or underdominant mutations. We also describe a method that allows genetic analysis of reproductive isolation between species that produce completely sterile or inviable hybrids. Such species pairs, which represent the final stage of speciation, cannot be analyzed by traditional methods. The X chromosome also plays an important role in postzygotic isolation between these species.

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Reproductive Isolation Between Isozyme Groups of Glycine tomentella (Leguminosae), and Spontaneous Doubling in Their Hybrids

Australian Journal of Botany ◽

10.1071/bt9860523 ◽

1986 ◽

Vol 34 (5) ◽

pp. 523 ◽

Cited By ~ 28

Author(s):

MJ Doyle ◽

JE Grant ◽

AHD Brown

Keyword(s):

Chromosome Number ◽

Reproductive Isolation ◽

Hybrid Sterility ◽

Gene Pools ◽

Single Chromosome ◽

Glycine Tomentella ◽

Hybrid Plants ◽

Genomic Divergence ◽

Close Relationship ◽

Mother Cells

Previous studies of infraspecific isozyme variation in Glycine tornentella have recognised five tetraploid (TI, T2, ... T5) and seven diploid (Dl, D2, ... D7) subspecific groups. This report analyses the meiosis in pollen mother cells of 31 new tetraploid hybrids, 10 diploid hybrids and three diploid by tetraploid combinations. A close relationship, over the range of diversity, was observed between isozyme similarity of the parents of hybrids and chromosome pairing at meiosis. In general, hybrids between parents belonging to the same isozyme group were fertile whereas hybrids between groups were sterile. In the tetraploids, the fertility of interregional hybrids when the accessions belonged to the same group confirmed the widespread distribution of groups T1 and T4. Alternatively, the sterility of intraregional hybrids between groups showed that groups can coexist and remain as separate gene pools. Each isozyme group apparently had a single chromosome number (TI and T5 had 2n = 78; T2, T3 and T4 had 2n = 80). Some otherwise sterile hybrid plants produced rare progeny with elevated chromosome num- ber, probably from the functioning of unreduced male and female gametes. Considerable genomic divergence was apparent from the hybrids between diploid groups, comparable with that found between recognised Glycine species. Again isozyme groups had a characteristic chromosome number (Dl and D2 had 2n = 38, the remainder had 2n = 40). Thus reproductive isolation through reduced formation of bivalents at meiosis operated both between and within cytotypes (2n = 38, 40, 78, 80) of G. tornentella. The pattern of hybrid sterility was as predicted from the analysis of isozyme similarity, confirming the grouping as a meaningful classification within this diverse species.

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The genome of the zoonotic malaria parasite Plasmodium simium reveals adaptations to host-switching

10.1101/841171 ◽

2019 ◽

Cited By ~ 1

Author(s):

Tobias Mourier ◽

Denise Anete Madureira de Alvarenga ◽

Abhinav Kaushik ◽

Anielle de Pina-Costa ◽

Olga Douvropoulou ◽

...

Keyword(s):

Malaria Parasite ◽

Binding Protein ◽

Phylogenetic Analyses ◽

Rapid Evolution ◽

Nucleotide Polymorphisms ◽

Coding Region ◽

Genetic Changes ◽

Zoonotic Infections ◽

Large Deletions ◽

Erythrocyte Invasion

SummaryPlasmodium simium, a malaria parasite of non-human primates in the Atlantic forest region of Brazil was recently shown to cause zoonotic infections in humans. Phylogenetic analyses based on the whole genome sequences of six P. simium isolates from humans and two isolates from brown howler monkeys revealed that P. simium is monophyletic within the broader diversity of South American Plasmodium vivax, consistent with the hypothesis that P. simium first infected non-human primates as a result of a host-switch of P. vivax from humans. Very low levels of genetic diversity within P. simium and the absence of P. simium-P. vivax hybrids suggest that the P. simium population emerged recently with a subsequent period of independent evolution in Platyrrhini monkeys. We find that Plasmodium Interspersed Repeat (PIR) genes, Plasmodium Helical Interspersed Subtelomeric (PHIST) genes and Tryptophan-Rich Antigen (TRAg) genes in P. simium are divergent from P. vivax orthologues and are enriched for non-synonymous single nucleotide polymorphisms, consistent with the rapid evolution of these genes. Analysis of genes involved in erythrocyte invasion revealed several notable differences between P. vivax and P. simium, including large deletions within the coding region of the Duffy Binding Protein 1 (DBP1) and Reticulocyte Binding Protein 2a (RBP2a) genes of P. simium. Sequence analysis of P. simium isolates from non-human primates (NHPs) and zoonotic human infections revealed a deletion of 38 amino acids in DBP1 present in all human-derived isolates, whereas NHP isolates were multi-allelic at this locus. We speculate that these deletions in key erythrocyte invasion ligands along with other significant genetic changes may have facilitated zoonotic transfer to humans. NHPs are a reservoir of parasites potentially infectious to humans that must be considered in malaria eradication efforts. The P. simium genome is an important resource for understanding the mechanisms of malaria parasite zoonoses.

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Linking morphological and molecular sources to disentangle the case of Xylodon australis

Scientific Reports ◽

10.1038/s41598-020-78399-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Javier Fernández-López ◽

M. Teresa Telleria ◽

Margarita Dueñas ◽

Mara Laguna-Castro ◽

Klaus Schliep ◽

...

Keyword(s):

New Zealand ◽

Phylogenetic Analyses ◽

Single Species ◽

R Package ◽

Molecular Data ◽

Historical Collections ◽

Close Relationship ◽

Kinship Relations ◽

History Of ◽

Different Sources

AbstractThe use of different sources of evidence has been recommended in order to conduct species delimitation analyses to solve taxonomic issues. In this study, we use a maximum likelihood framework to combine morphological and molecular traits to study the case of Xylodon australis (Hymenochaetales, Basidiomycota) using the locate.yeti function from the phytools R package. Xylodon australis has been considered a single species distributed across Australia, New Zealand and Patagonia. Multi-locus phylogenetic analyses were conducted to unmask the actual diversity under X. australis as well as the kinship relations respect their relatives. To assess the taxonomic position of each clade, locate.yeti function was used to locate in a molecular phylogeny the X. australis type material for which no molecular data was available using morphological continuous traits. Two different species were distinguished under the X. australis name, one from Australia–New Zealand and other from Patagonia. In addition, a close relationship with Xylodon lenis, a species from the South East of Asia, was confirmed for the Patagonian clade. We discuss the implications of our results for the biogeographical history of this genus and we evaluate the potential of this method to be used with historical collections for which molecular data is not available.

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How Can Satellite DNA Divergence Cause Reproductive Isolation? Let Us Count the Chromosomal Ways

Genetics Research International ◽

10.1155/2012/430136 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 16

Author(s):

Patrick M. Ferree ◽

Satyaki Prasad

Keyword(s):

Reproductive Isolation ◽

Developmental Stages ◽

Rapid Evolution ◽

Model Organisms ◽

Cellular Mechanisms ◽

Closely Related Species ◽

Heterochromatin Formation ◽

Interspecies Hybrids ◽

Postzygotic Reproductive Isolation ◽

And Function

Satellites are one of the most enigmatic parts of the eukaryotic genome. These highly repetitive, noncoding sequences make up as much as half or more of the genomic content and are known to play essential roles in chromosome segregation during meiosis and mitosis, yet they evolve rapidly between closely related species. Research over the last several decades has revealed that satellite divergence can serve as a formidable reproductive barrier between sibling species. Here we highlight several key studies on Drosophila and other model organisms demonstrating deleterious effects of satellites and their rapid evolution on the structure and function of chromosomes in interspecies hybrids. These studies demonstrate that satellites can impact chromosomes at a number of different developmental stages and through distinct cellular mechanisms, including heterochromatin formation. These findings have important implications for how loci that cause postzygotic reproductive isolation are viewed.

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A new species of Cleistocybe (Agaricales, Basidiomycota) from the Tibetan Plateau, China

Phytotaxa ◽

10.11646/phytotaxa.336.3.7 ◽

2018 ◽

Vol 336 (3) ◽

pp. 286 ◽

Cited By ~ 2

Author(s):

HONG-MEI WU ◽

JIA-QI LUO ◽

KE WANG ◽

RUN-CHAO ZHANG ◽

YI LI ◽

...

Keyword(s):

New Species ◽

Tibetan Plateau ◽

Phylogenetic Analyses ◽

Morphological Observation ◽

Morphological Description ◽

The Tibetan Plateau ◽

Sequence Analyses ◽

The North ◽

Close Relationship ◽

A New Species

During field expeditions to the Tibetan Plateau, a collection of an undescribed species with several basidiomes was found. Morphological observation and DNA sequence analyses of the collection revealed a close relationship with Cleistocybe vernalis, the type species of the genus Cleistocybe. Therefore, a new species is proposed for the fungus with full morphological description accompanied by phylogenetic analyses. The discovery of the species extends the reported distribution of the genus from the north of America and Europe to Asia.

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An expanded concept of Madisonia including miscellaneous species of Pleurothallidinae (Orchidaceae): evidence from molecular analysis

Phytotaxa ◽

10.11646/phytotaxa.505.1.5 ◽

2021 ◽

Vol 505 (1) ◽

pp. 71-84

Author(s):

ERIC DE CAMARGO SMIDT ◽

A. L. V. TOSCANO DE BRITO ◽

ANNA VICTORIA SILVÉRIO R. MAUAD ◽

NICOLÁS GUTIÉRREZ MORALES

Keyword(s):

Molecular Analysis ◽

Amazon Basin ◽

Phylogenetic Analyses ◽

Monotypic Genus ◽

Phylogenetic Information ◽

Close Relationship ◽

The Caribbean ◽

Taxonomic Studies ◽

Expanded Concept ◽

New Nomenclatural Combinations

Prior taxonomic studies in subtribe Pleurothallidinae have suggested a close relationship between miscellaneous species featuring long-repent, segmented rhizomes, abbreviated ramicauls, few-flowered inflorescences, and flowers with partially connate sepals and trilobed lip. The lack of phylogenetic information for most species has prevented further conclusions or changes in their taxonomy; and as a result, they are currently assigned to several unrelated genera: Anathallis, Madisonia, Pabstiella, Pleurothallis, Sansonia and Specklinia. We performed phylogenetic analyses using nuclear (nrITS) and five plastid (matK, psbD-trnT, rps16-trnQ, trnH-psbA and trnS-trnG) markers and demonstrated that these species form an isolated clade which requires generic recognition. The name Madisonia, previously a monotypic genus endemic of the Amazon basin, is re-circumscribed and expanded to include nine species distributed in the Atlantic Rainforest and the Caribbean. Eight new nomenclatural combinations are proposed.

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PRDM9 Diversity at Fine Geographical Scale Reveals Contrasting Evolutionary Patterns and Functional Constraints in Natural Populations of House Mice

Molecular Biology and Evolution ◽

10.1093/molbev/msz091 ◽

2019 ◽

Vol 36 (8) ◽

pp. 1686-1700 ◽

Cited By ~ 4

Author(s):

Covadonga Vara ◽

Laia Capilla ◽

Luca Ferretti ◽

Alice Ledda ◽

Rosa A Sánchez-Guillén ◽

...

Keyword(s):

Reproductive Isolation ◽

Evolutionary Biology ◽

Evolutionary Dynamics ◽

Rapid Evolution ◽

Natural Populations ◽

Global Scale ◽

House Mice ◽

Functional Constraints ◽

Evolutionary Patterns ◽

Data Set

Abstract One of the major challenges in evolutionary biology is the identification of the genetic basis of postzygotic reproductive isolation. Given its pivotal role in this process, here we explore the drivers that may account for the evolutionary dynamics of the PRDM9 gene between continental and island systems of chromosomal variation in house mice. Using a data set of nearly 400 wild-caught mice of Robertsonian systems, we identify the extent of PRDM9 diversity in natural house mouse populations, determine the phylogeography of PRDM9 at a local and global scale based on a new measure of pairwise genetic divergence, and analyze selective constraints. We find 57 newly described PRDM9 variants, this diversity being especially high on Madeira Island, a result that is contrary to the expectations of reduced variation for island populations. Our analysis suggest that the PRDM9 allelic variability observed in Madeira mice might be influenced by the presence of distinct chromosomal fusions resulting from a complex pattern of introgression or multiple colonization events onto the island. Importantly, we detect a significant reduction in the proportion of PRDM9 heterozygotes in Robertsonian mice, which showed a high degree of similarity in the amino acids responsible for protein–DNA binding. Our results suggest that despite the rapid evolution of PRDM9 and the variability detected in natural populations, functional constraints could facilitate the accumulation of allelic combinations that maintain recombination hotspot symmetry. We anticipate that our study will provide the basis for examining the role of different PRDM9 genetic backgrounds in reproductive isolation in natural populations.

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Systematic Status of a Midwater Population of Freshwater Sculpin (Cottus) from Lake Washington, Seattle, Washington

Journal of the Fisheries Research Board of Canada ◽

10.1139/f75-003 ◽

1975 ◽

Vol 32 (1) ◽

pp. 21-28 ◽

Cited By ~ 1

Author(s):

K. W. Larson ◽

G. W. Brown Jr.

Keyword(s):

Reproductive Isolation ◽

Canal System ◽

Systematic Status ◽

Close Relationship ◽

Lake Washington ◽

Freshwater Sculpin

A population of freshwater sculpin from Lake Washington differs from other species of the typically benthic genus Cottus in that individuals migrate nightly to the surface and midwaters. Individuals are phenotypically and biochemically similar to Cottus aleuticus, but have a longer, more terete body, a larger cephalic pore and canal system, shorter pelvic fins, and a higher frequency of individuals with seven branchiostegal rays per side.A close relationship between the Lake Washington population and C. aleuticus seems indicated because of their phenotypic and biochemical similarities and because of the existence of individuals in other Northwest lakes that appear intermediate in character between C. aleuticus and the Lake Washington population. The decision as to the specific status of the Lake Washington population is deferred until more is known of its degree of reproductive isolation from C. aleuticus and of the existence of these possibly intermediate populations.

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Phylogeny and morphology of genus Nephrocytium (Sphaeropleales, Chlorophyceae, Chlorophyta) from China

Phytotaxa ◽

10.11646/phytotaxa.319.1.4 ◽

2017 ◽

Vol 319 (1) ◽

pp. 84 ◽

Cited By ~ 2

Author(s):

XUDONG LIU ◽

HUAN ZHU ◽

BENWEN LIU ◽

GUOXIANG LIU ◽

ZHENGYU HU

Keyword(s):

Phylogenetic Analyses ◽

Light And Electron Microscopy ◽

Taxonomic Position ◽

Phylogenetic Position ◽

Phytoplankton Communities ◽

Close Phylogenetic Relationship ◽

The Family ◽

Close Relationship ◽

Molecular Phylogenetic

The genus Nephrocytium Nägeli is a common member of phytoplankton communities that has a distinctive morphology. Its taxonomic position is traditionally considered to be within the family Oocystaceae (Trebouxiophyceae). However, research on its ultrastructure is rare, and the phylogenetic position has not yet been determined. In this study, two strains of Nephrocytium, N. agardhianum Nägeli and N. limneticum (G.M.Smith) G.M.Smith, were identified and successfully cultured in the laboratory. Morphological inspection by light and electron microscopy and molecular phylogenetic analyses were performed to explore the taxonomic position. Ultrastructure implied a likely irregular network of dense and fine ribs on the surface of the daughter cell wall that resembled that of the genus Chromochloris Kol & Chodat (Chromochloridaceae). Phylogenetic analyses revealed that Nephrocytium formed an independent lineage in the order Sphaeropleales (Chlorophyceae) with high support values and a close phylogenetic relationship with Chromochloris. Based on combined morphological, ultrastructural and phylogenetic data, we propose a re-classification of Nephrocytium into Sphaeropleales, sharing a close relationship with Chromochloris.

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