scholarly journals Estimates of gene flow among populations, geographic races, and species in the Ipomopsis aggregata complex.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 639-647
Author(s):  
P G Wolf ◽  
P S Soltis
Keyword(s):  
Gene Flow ◽  
Genetic Exchange ◽  
Morphological Evidence ◽  
Ipomopsis Aggregata ◽  
Allozyme Data ◽  
Interspecific Gene Flow ◽  
Geographic Race ◽  
Perennial Herbs ◽  
Estimate Gene Flow ◽  
F Statistics

Abstract Interpopulational gene flow within a species can reduce population differentiation due to genetic drift, whereas genetic exchange among taxa can impede speciation. We used allozyme data to estimate gene flow within and among geographic races and species of perennial herbs in the Ipomopsis aggregata complex (Polemoniaceae). Estimates of interpopulational gene flow within taxa from two methods (F statistics and private alleles) were correlated with one another. Gene flow among populations within each geographic race (subspecies) of I. aggregata was relatively high (Nm greater than approximately 1.0). Gene flow was also high among populations of I. arizonica and among four northern populations of I. tenuituba. However, gene flow was low (Nm less than 1.0) for I. tenuituba when a population representing subsp. macrosiphon was included. This is consistent with previous findings that subsp. macrosiphon has had an independent origin and is reproductively, as well as geographically, isolated. A recently developed model, based on hierarchical F statistics, was employed to estimate genetic exchange among taxa. Gene flow estimates were generally high among races of I. aggregata (dNmrace greater than 1.0) but were low among subspecies of I. tenuituba (dNmrace less than 1.0). Consistent with morphological evidence, estimates of interspecific gene flow were moderate between I. aggregata and I. tenuituba, which hybridize in several areas. However, contrary to morphological evidence, we estimated relatively high levels of interspecific gene flow involving I. arizonica. Our results suggest that I. arizonica has hybridized with other species without the transfer of morphological traits.(ABSTRACT TRUNCATED AT 250 WORDS)

Genealogy and gene flow among annual domesticated species of Cucurbita

1990 ◽  
Vol 68 (4) ◽  
pp. 782-789 ◽  
Author(s):  
D. S. Decker-Walters ◽  
T. W. Walters ◽  
U. Posluszny ◽  
P. G. Kevan
Keyword(s):  
Gene Flow ◽  
Common Ancestor ◽  
Phylogenetic Analyses ◽  
Allelic Diversity ◽  
Morphological Characters ◽  
Morphological Evidence ◽  
Allozyme Data ◽  
Interspecific Gene Flow ◽  
Morphological Heterogeneity ◽  
Northwestern Mexico

Over the years, workers have gathered data from various sources in the attempt to understand the evolutionary histories and relationships of the domesticated members of Cucurbita. We used allozyme data to address questions of genealogy, interspecific gene flow, and allelic diversity for 23 commercial cultivars and 17 indigenous landraces of C. maxima, C. mixta, C. moschata, and C. pepo. Allelic diversity was greatest in C. pepo (especially ssp. ovifera) and C. moschata, reflecting complex histories for these taxa. Cucurbita maxima and C. mixta were relatively homogeneous despite morphological heterogeneity. Infraspecific classifications based on morphological characters were not supported by the allozyme data for C. maxima, C. mixta, and C. moschata. The allozymes supported morphological evidence of introgression from C. mixta in Oriental cultivars and southwestern United States and northwestern Mexico landraces of C. moschata. Phylogenetic analyses indicated that C. moschata and C. mixta are probably sister species and that C. pepo shares a common ancestor with these species that is not shared with C. maxima.

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

scholarly journals Linked vs. unlinked markers: multilocus microsatellite haplotype-sharing as a tool to estimate gene flow and introgression

2006 ◽  
Vol 16 (2) ◽  
pp. 243-256 ◽  
Author(s):  
WIM J. M. KOOPMAN ◽  
YINGHUI LI ◽  
ELS COART ◽  
W. ERIC VAN DE WEG ◽  
BEN VOSMAN ◽  
...  
Keyword(s):  
Gene Flow ◽  
Haplotype Sharing ◽  
Microsatellite Haplotype ◽  
Estimate Gene Flow

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

scholarly journals Gene Flow in Phaseolus Beans and Its Role as a Plausible Driver of Ecological Fitness and Expansion of Cultigens

2021 ◽  
Vol 9 ◽  
Author(s):  
María Isabel Chacón-Sánchez ◽  
Jaime Martínez-Castillo ◽  
Jorge Duitama ◽  
Daniel G. Debouck
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Time Perspective ◽  
Lima Bean ◽  
Breeding Systems ◽  
Large Contribution ◽  
Interspecific Gene Flow ◽  
Ecological Fitness ◽  
Technological Advances ◽  
Evolutionary Force

The genus Phaseolus, native to the Americas, is composed of more than eighty wild species, five of which were domesticated in pre-Columbian times. Since the beginning of domestication events in this genus, ample opportunities for gene flow with wild relatives have existed. The present work reviews the extent of gene flow in the genus Phaseolus in primary and secondary areas of domestication with the aim of illustrating how this evolutionary force may have conditioned ecological fitness and the widespread adoption of cultigens. We focus on the biological bases of gene flow in the genus Phaseolus from a spatial and time perspective, the dynamics of wild-weedy-crop complexes in the common bean and the Lima bean, the two most important domesticated species of the genus, and the usefulness of genomic tools to detect inter and intraspecific introgression events. In this review we discuss the reproductive strategies of several Phaseolus species, the factors that may favor outcrossing rates and evidence suggesting that interspecific gene flow may increase ecological fitness of wild populations. We also show that wild-weedy-crop complexes generate genetic diversity over which farmers are able to select and expand their cultigens outside primary areas of domestication. Ultimately, we argue that more studies are needed on the reproductive biology of the genus Phaseolus since for most species breeding systems are largely unknown. We also argue that there is an urgent need to preserve wild-weedy-crop complexes and characterize the genetic diversity generated by them, in particular the genome-wide effects of introgressions and their value for breeding programs. Recent technological advances in genomics, coupled with agronomic characterizations, may make a large contribution.

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 Site-Specific Insertion Polymorphism of the MITE Alex-1 in the Genus Coffea Suggests Interspecific Gene Flow

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Christine Dubreuil-Tranchant ◽  
Romain Guyot ◽  
Amira Guellim ◽  
Caroline Duret ◽  
Marion de la Mare ◽  
...  
Keyword(s):  
Gene Flow ◽  
Transposable Elements ◽  
Phylogenetic Relationships ◽  
Insertion Site ◽  
Coffea Canephora ◽  
Insertion Polymorphism ◽  
Interspecific Gene Flow ◽  
Species Analysis ◽  
Eukaryotic Genomes ◽  
Mite Family

Miniature Inverted-repeat Transposable Elements (MITEs) are small nonautonomous class-II transposable elements distributed throughout eukaryotic genomes. We identified a novel family of MITEs (named Alex) in the Coffea canephora genome often associated with expressed sequences. The Alex-1 element is inserted in an intron of a gene at the CcEIN4 locus. Its mobility was demonstrated by sequencing the insertion site in C. canephora accessions and Coffea species. Analysis of the insertion polymorphism of Alex-1 at this locus in Coffea species and in C. canephora showed that there was no relationship between the geographical distribution of the species, their phylogenetic relationships, and insertion polymorphism. The intraspecific distribution of C. canephora revealed an original situation within the E diversity group. These results suggest possibly greater gene flow between species than previously thought. This MITE family will enable the study of the C. canephora genome evolution, phylogenetic relationships, and possible gene flows within the Coffea genus.

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