scholarly journals Parthenogenesis as a solution to hybrid sterility: the mechanistic basis of meiotic distortions in clonal and sterile hybrids

2019 ◽  
Author(s):  
Dmitrij Dedukh ◽  
Zuzana Majtánová ◽  
Anatolie Marta ◽  
Martin Pšenička ◽  
Jan Kotusz ◽  
...  
Keyword(s):  
Gene Flow ◽  
Molecular Mechanisms ◽  
Hybrid Sterility ◽  
Biological Species ◽  
Female Fertility ◽  
Interspecific Gene Flow ◽  
General Validity ◽  
Specific Manner ◽  
Postzygotic Barriers ◽  
Mechanistic Basis

AbstractFormation of species generally occurs in a continuum from potentially intermixing populations to independent entities isolated from other species by pre- and postzygotic barriers. Especially the establishment of hybrid sterility (HS) is a hallmark of speciation, which usually emerges at different rates between hybrid sexes. However, although HS is frequently observed, the underlying molecular mechanisms remain poorly understood. Here we report that speciation proceeds through a previously unnoticed stage at which gene flow is completely interrupted on side of both hybrid’s sexes, although only male hybrids are sterile, while female fertility is rescued due to a particular gametogenetic deviation leading to the formation of clonal gametes. Specifically, analysis of gametogenetic pathways in hybrids between fish species Cobitis elongatoides and C. taenia revealed that male HS resulted from extensive asynapses and crossover reduction among elongatoides-taenia chromosomal pairs followed by apoptosis. By contrast, hybrid females exhibited premeiotic genome endoreplication which ensured proper formation of bivalents between identical chromosomal copies. This deviation ultimately restored fertility in females but since it simultaneously leads to the production of unreduced clonal gametes, it restricts interspecific gene flow thereby directly contributing to speciation. In conclusion, our data demonstrate that the emergence of asexuality may remedy HS in a sex-specific manner and is intermingled with the speciation process. Although gametogenetic mechanisms employed by asexual animals and plants have rarely been scrutinized, available evidence suggests that premeiotic endoreplication is relatively widespread. This suggests that observed link between HS and clonality may have general validity in taxa able of asexual reproduction.Author’s summarySpecies are fundamental evolutionary units that presumably evolve in a continuum from potentially intermixing populations to independent entities isolated from other species by pre- and postzygotic barriers. Especially the establishment of hybrid sterility (HS) is a hallmark of speciation, which usually emerges at different rates between hybrid sexes. However, although HS is frequently observed, the underlying molecular mechanisms remain poorly understood. Here we report the existence of a previously unnoticed stage of speciation at which gene flow is completely interrupted, although only male hybrids are sterile, while female fertility is rescued due to a particular gametogenetic deviation leading to formation of clonal gametes. Specifically, HS resulted from extensive asynapses in male gonads, but in females the hybridization provoked premeiotic endoreplication which rescued chromosome pairing and fertility. Simultaneously, this meiotic deviation caused clonal transmission of maternal genome, thereby effectively restricting the interspeficic gene flow. Our results emphasize that emergence of clonality is a type of hybrid incompatibility that is intermingled with the formation of biological species and may remedy hybrid sterility in a sex-specific manner.

scholarly journals Parthenogenesis as a Solution to Hybrid Sterility: The Mechanistic Basis of Meiotic Distortions in Clonal and Sterile Hybrids

Genetics ◽  
2020 ◽  
Vol 215 (4) ◽  
pp. 975-987 ◽  
Author(s):  
Dmitrij Dedukh ◽  
Zuzana Majtánová ◽  
Anatolie Marta ◽  
Martin Pšenička ◽  
Jan Kotusz ◽  
...  
Keyword(s):  
Gene Flow ◽  
Molecular Mechanisms ◽  
Hybrid Sterility ◽  
Triploid Hybrid ◽  
Interspecific Gene Flow ◽  
Homologous Chromosomes ◽  
Specific Manner ◽  
Bivalent Formation ◽  
Mechanistic Basis ◽  
Sterile Hybrids

Hybrid sterility is a hallmark of speciation, but the underlying molecular mechanisms remain poorly understood. Here, we report that speciation may regularly proceed through a stage at which gene flow is completely interrupted, but hybrid sterility occurs only in male hybrids whereas female hybrids reproduce asexually. We analyzed gametogenic pathways in hybrids between the fish species Cobitis elongatoides and C. taenia, and revealed that male hybrids were sterile owing to extensive asynapsis and crossover reduction among heterospecific chromosomal pairs in their gametes, which was subsequently followed by apoptosis. We found that polyploidization allowed pairing between homologous chromosomes and therefore partially rescued the bivalent formation and crossover rates in triploid hybrid males. However, it was not sufficient to overcome sterility. In contrast, both diploid and triploid hybrid females exhibited premeiotic genome endoreplication, thereby ensuring proper bivalent formation between identical chromosomal copies. This endoreplication ultimately restored female fertility but it simultaneously resulted in the obligate production of clonal gametes, preventing any interspecific gene flow. In conclusion, we demonstrate that the emergence of asexuality can remedy hybrid sterility in a sex-specific manner and contributes to the speciation process.

scholarly journals The rate of evolution of postmating-prezygotic reproductive isolation in Drosophila

2017 ◽  
Author(s):  
David A. Turissini ◽  
Joseph A. McGirr ◽  
Sonali S. Patel ◽  
Jean R. David ◽  
Daniel R. Matute
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Hybrid Sterility ◽  
Biological Species ◽  
Biological Species Concept ◽  
Premating Isolation ◽  
Hybrid Inviability ◽  
Systematic Analysis ◽  
Rates Of Evolution ◽  
Postzygotic Barriers

ABSTRACTReproductive isolation (RI) is an intrinsic aspect of species, as described in the Biological Species Concept. For that reason, the identification of the precise traits and mechanisms of RI, and the rates at which they evolve, is crucial to understanding how species originate and persist. Nonetheless, precise measurements of the magnitude of reproductive isolation are rare. Previous work has measured the rates of evolution of prezygotic and postzygotic barriers to gene flow, yet no systematic analysis has carried out the study of the rates of evolution of postmating-prezygotic (PMPZ) barriers. We systematically measured the magnitude of two barriers to gene flow that act after mating occurs but before zygotic fertilization and also measured a premating (female mating rate in nonchoice experiments) and two postzygotic barriers (hybrid inviability and hybrid sterility) for all pairwise crosses of species within the Drosophila melanogaster subgroup. Our results indicate that PMPZ isolation evolves faster than hybrid inviability but slower than premating isolation. We also describe seven new interspecific hybrids in the group. Our findings open up a large repertoire of tools that will enable researchers to manipulate hybrids and explore the genetic basis of interspecific differentiation, reproductive isolation, and speciation.

scholarly journals Endosperm-based hybridization barriers explain the pattern of gene flow between Arabidopsis lyrata and Arabidopsis arenosa in Central Europe

2017 ◽  
Vol 114 (6) ◽  
pp. E1027-E1035 ◽  
Author(s):  
Clément Lafon-Placette ◽  
Ida M. Johannessen ◽  
Karina S. Hornslien ◽  
Mohammad F. Ali ◽  
Katrine N. Bjerkan ◽  
...  
Keyword(s):  
Gene Flow ◽  
Central Europe ◽  
Diploid Species ◽  
Biological Species ◽  
Biological Species Concept ◽  
Interspecific Gene Flow ◽  
Seed Formation ◽  
Arabidopsis Lyrata ◽  
Hybrid Seeds ◽  
Arabidopsis Arenosa

Based on the biological species concept, two species are considered distinct if reproductive barriers prevent gene flow between them. In Central Europe, the diploid species Arabidopsis lyrata and Arabidopsis arenosa are genetically isolated, thus fitting this concept as “good species.” Nonetheless, interspecific gene flow involving their tetraploid forms has been described. The reasons for this ploidy-dependent reproductive isolation remain unknown. Here, we show that hybridization between diploid A. lyrata and A. arenosa causes mainly inviable seed formation, revealing a strong postzygotic reproductive barrier separating these two species. Although viability of hybrid seeds was impaired in both directions of hybridization, the cause for seed arrest differed. Hybridization of A. lyrata seed parents with A. arenosa pollen donors resulted in failure of endosperm cellularization, whereas the endosperm of reciprocal hybrids cellularized precociously. Endosperm cellularization failure in both hybridization directions is likely causal for the embryo arrest. Importantly, natural tetraploid A. lyrata was able to form viable hybrid seeds with diploid and tetraploid A. arenosa, associated with the reestablishment of normal endosperm cellularization. Conversely, the defects of hybrid seeds between tetraploid A. arenosa and diploid A. lyrata were aggravated. According to these results, we hypothesize that a tetraploidization event in A. lyrata allowed the production of viable hybrid seeds with A. arenosa, enabling gene flow between the two species.

scholarly journals Absence of heterosis in hybrid crested newts

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5317 ◽  
Author(s):  
Jan W. Arntzen ◽  
Nazan Üzüm ◽  
Maja D. Ajduković ◽  
Ana Ivanović ◽  
Ben Wielstra
Keyword(s):  
Gene Flow ◽  
Hybrid Zone ◽  
Hybrid Sterility ◽  
Introgressive Hybridization ◽  
Growth Curves ◽  
Hybrid Zones ◽  
Population Demography ◽  
Interspecific Gene Flow ◽  
Fertile Hybrids ◽  
Intermediate Situation

Relationships between phylogenetic relatedness, hybrid zone spatial structure, the amount of interspecific gene flow and population demography were investigated, with the newt genusTriturusas a model system. In earlier work, a bimodal hybrid zone of two distantly related species combined low interspecific gene flow with hybrid sterility and heterosis was documented. Apart from that, a suite of unimodal hybrid zones in closely relatedTriturusshowed more or less extensive introgressive hybridization with no evidence for heterosis. We here report on population demography and interspecific gene flow in twoTriturusspecies (T. macedonicusandT. ivanbureschiin Serbia). These are two that are moderately related, engage in a heterogeneous uni-/bimodal hybrid zone and hence represent an intermediate situation. This study used 13 diagnostic nuclear genetic markers in a population at the species contact zone. This showed that all individuals were hybrids, with no parentals detected. Age, size and longevity and the estimated growth curves are not exceeding that of the parental species, so that we conclude the absence of heterosis inT. macedonicus–T. ivanbureschi. Observations across the genus support the hypothesis that fertile hybrids allocate resources to reproduction and infertile hybrids allocate resources to growth. SeveralTriturusspecies hybrid zones not yet studied allow the testing of this hypothesis.

scholarly journals Steroidal Regulation of Oviductal microRNAs Is Associated with microRNA-Processing in Beef Cows

2021 ◽  
Vol 22 (2) ◽  
pp. 953
Author(s):  
Angela Maria Gonella-Diaza ◽  
Everton Lopes ◽  
Kauê Ribeiro da Silva ◽  
Ricardo Perecin Nociti ◽  
Gabriella Mamede Andrade ◽  
...  
Keyword(s):  
Mirna Expression ◽  
Sex Steroids ◽  
Molecular Mechanisms ◽  
Beef Cows ◽  
Early Embryo ◽  
Preovulatory Follicle ◽  
Large Follicle ◽  
Specific Manner ◽  
Microrna Processing ◽  
Small Follicle

Information on molecular mechanisms through which sex-steroids regulate oviductal function to support early embryo development is lacking. Here, we hypothesized that the periovulatory endocrine milieu affects the miRNA processing machinery and miRNA expression in bovine oviductal tissues. Growth of the preovulatory follicle was controlled to obtain cows that ovulated a small follicle (SF) and subsequently bore a small corpus luteum (CL; SF-SCL) or a large follicle (LF) and large CL (LF-LCL). These groups differed in the periovulatory plasmatic sex-steroid’s concentrations. Ampulla and isthmus samples were collected on day four of the estrous cycle. Abundance of DROSHA, DICER1, and AGO4 transcripts was greater in the ampulla than the isthmus. In the ampulla, transcription of these genes was greater for the SF-SCL group, while the opposite was observed in the isthmus. The expression of the 88 most abundant miRNAs and 14 miRNAs in the ampulla and 34 miRNAs in isthmus were differentially expressed between LF-LCL and SF-SCL groups. Integration of transcriptomic and miRNA data and molecular pathways enrichment showed that important pathways were inhibited in the SF-SCL group due to miRNA control. In conclusion, the endocrine milieu affects the miRNA expression in the bovine oviduct in a region-specific manner.

scholarly journals Role of Long Non-Coding RNAs and the Molecular Mechanisms Involved in Insulin Resistance

2021 ◽  
Vol 22 (14) ◽  
pp. 7256
Author(s):  
Vianet Argelia Tello-Flores ◽  
Fredy Omar Beltrán-Anaya ◽  
Marco Antonio Ramírez-Vargas ◽  
Brenda Ely Esteban-Casales ◽  
Napoleón Navarro-Tito ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Biological Species ◽  
Necrosis Factor Alpha ◽  
Polypyrimidine Tract Binding Protein ◽  
Non Coding Rnas

Long non-coding RNAs (lncRNAs) are single-stranded RNA biomolecules with a length of >200 nt, and they are currently considered to be master regulators of many pathological processes. Recent publications have shown that lncRNAs play important roles in the pathogenesis and progression of insulin resistance (IR) and glucose homeostasis by regulating inflammatory and lipogenic processes. lncRNAs regulate gene expression by binding to other non-coding RNAs, mRNAs, proteins, and DNA. In recent years, several mechanisms have been reported to explain the key roles of lncRNAs in the development of IR, including metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), imprinted maternal-ly expressed transcript (H19), maternally expressed gene 3 (MEG3), myocardial infarction-associated transcript (MIAT), and steroid receptor RNA activator (SRA), HOX transcript antisense RNA (HOTAIR), and downregulated Expression-Related Hexose/Glucose Transport Enhancer (DREH). LncRNAs participate in the regulation of lipid and carbohydrate metabolism, the inflammatory process, and oxidative stress through different pathways, such as cyclic adenosine monophosphate/protein kinase A (cAMP/PKA), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), polypyrimidine tract-binding protein 1/element-binding transcription factor 1c (PTBP1/SREBP-1c), AKT/nitric oxide synthase (eNOS), AKT/forkhead box O1 (FoxO1), and tumor necrosis factor-alpha (TNF-α)/c-Jun-N-terminal kinases (JNK). On the other hand, the mechanisms linked to the molecular, cellular, and biochemical actions of lncRNAs vary according to the tissue, biological species, and the severity of IR. Therefore, it is essential to elucidate the role of lncRNAs in the insulin signaling pathway and glucose and lipid metabolism. This review analyzes the function and molecular mechanisms of lncRNAs involved in the development of IR.

scholarly journals Molecular Signatures of Reticulate Evolution within the Complex of European Pine Taxa

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 489
Author(s):  
Bartosz Łabiszak ◽  
Witold Wachowiak
Keyword(s):  
Gene Flow ◽  
Reticulate Evolution ◽  
Modeling Framework ◽  
Closely Related Species ◽  
Interspecific Gene Flow ◽  
Nucleotide Sequence Variation ◽  
History Of ◽  
Best Fitting ◽  
Species Integrity

Speciation mechanisms, including the role of interspecific gene flow and introgression in the emergence of new species, are the major focus of evolutionary studies. Inference of taxonomic relationship between closely related species may be challenged by past hybridization events, but at the same time, it may provide new knowledge about mechanisms responsible for the maintenance of species integrity despite interspecific gene flow. Here, using nucleotide sequence variation and utilizing a coalescent modeling framework, we tested the role of hybridization and introgression in the evolutionary history of closely related pine taxa from the Pinus mugo complex and P. sylvestris. We compared the patterns of polymorphism and divergence between taxa and found a great overlap of neutral variation within the P. mugo complex. Our phylogeny reconstruction indicated multiple instances of reticulation events in the past, suggesting an important role of interspecific gene flow in the species divergence. The best-fitting model revealed P. mugo and P. uncinata as sister species with basal P. uliginosa and asymmetric migration between all investigated species after their divergence. The magnitude of interspecies gene flow differed greatly, and it was consistently stronger from representatives of P. mugo complex to P. sylvestris than in the opposite direction. The results indicate the prominent role of reticulation evolution in those forest trees and provide a genetic framework to study species integrity maintained by selection and local adaptation.

scholarly journals Interspecific Gene Flow Shaped the Evolution of the Genus Canis

2019 ◽  
Vol 29 (23) ◽  
pp. 4152 ◽  
Author(s):  
Shyam Gopalakrishnan ◽  
Mikkel-Holger S. Sinding ◽  
Jazmín Ramos-Madrigal ◽  
Jonas Niemann ◽  
Jose A. Samaniego Castruita ◽  
...  
Keyword(s):  
Gene Flow ◽  
Interspecific Gene Flow

Age- and stage-specific regulation patterns in the hematopoietic stem cell hierarchy

Blood ◽  
2001 ◽  
Vol 98 (10) ◽  
pp. 2966-2972 ◽  
Author(s):  
Hartmut Geiger ◽  
Jarrod M. True ◽  
Gerald de Haan ◽  
Gary Van Zant
Keyword(s):  
Linkage Analysis ◽  
Molecular Mechanisms ◽  
Hematopoietic Stem ◽  
Cell Compartments ◽  
Quantitative Trait Linkage Analysis ◽  
Specific Manner ◽  
Stem And Progenitor Cells ◽  
Specific Regulation ◽  
Stem Cell Hierarchy

Abstract The molecular mechanisms that regulate self-renewal and differentiation of very primitive hematopoietic stem and progenitor cells in vivo are still poorly understood. Despite the clinical relevance, even less is known about the mechanisms that regulate these cells in old animals. In a forward genetic approach, using quantitative trait linkage analysis in the mouse BXD recombinant inbred set, this study identified loci that regulate the genetic variation in the size of primitive hematopoietic cell compartments of young and old C57BL6 and DBA/2 animals. Linked loci were confirmed through the generation and analysis of congenic animals. In addition, a comparative linkage analysis revealed that the number of primitive hematopoietic cells and hematopoietic stem cells are regulated in a stage-specific and an age-specific manner.

Pleistocene survival, regional genetic structure and interspecific gene flow among three northern peat-mosses: Sphagnum inexspectatum , S. orientale and S. miyabeanum

2014 ◽  
Vol 42 (2) ◽  
pp. 364-376 ◽  
Author(s):  
A. Jonathan Shaw ◽  
Blanka Shaw ◽  
Hans K. Stenøien ◽  
G. Karen Golinski ◽  
Kristian Hassel ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Interspecific Gene Flow
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