scholarly journals Intraspecific Molecular Variation of Allium ursinum (Amaryllidaceae) Across the Border of Two Subspecies Distribution Ranges

2015 ◽  
Vol 57 (1) ◽  
pp. 31-43
Author(s):  
Kaja Rola ◽  
Anna Lenart-Boroń ◽  
Piotr Boroń ◽  
Piotr Osyczka
Keyword(s):  
Genetic Variability ◽  
Hybrid Zone ◽  
Mantel Test ◽  
Genetic Group ◽  
Secondary Contact ◽  
Putative Hybrid ◽  
Morphological Pattern ◽  
The Third ◽  
Allium Ursinum ◽  
Distribution Ranges

Abstract The study investigates the genetic differentiation among two subspecies of Allium ursinum L., namely A. ursinum subsp. ursinum and subsp. ucrainicum as well as their putative hybrid that is represented by individuals with intermediate morphology. Inter-Simple Sequence Repeats (ISSR) were applied to determine the status of intermediate morphotypes in terms of their genetic pattern and to assess the level of genetic variability within and between various populations of A. ursinum. The study comprises 144 specimens from nine populations along the east-west transect in Poland, which includes localities of both subspecies and their putative hybrid. Among the examined populations, 48 bands were amplified, of which 45 were found to be polymorphic. The principal coordinate analysis (PCoA), the neighbour-net analysis and Mantel test showed a strong correlation between genetic variability and geographic distance. Analysis of molecular variance (AMOVA) revealed that a greater proportion of total genetic variation resided within populations rather than among them. The Structure Bayesian clustering analysis revealed the presence of three distinct genetic groups within studied populations, where ‘eastern’ genotypes correspond to A. ursinum subsp. ucrainicum, and ‘western’ to subsp. ursinum; whereas the third genetic group has the largest share in the individuals occurring at the border of the distribution ranges of both subspecies. The emergence of the third genetic group is probably an effect of hybridization events occurring within the secondary contact zone. Typical morphologically intermediate populations occur only in a relatively narrow geographical zone, but the hybrid zone revealed by molecular markers is actually much wider than it is suggested by the morphological pattern of individuals. The current distribution pattern of both subspecies of A. ursinum and their hybrid zone is related to the two main directions of postglacial migration of Fagus sylvatica to the area of Poland. The hybrid zone arose as an effect of the secondary contact of two divergent lineages of A. ursinum.

Reassessment of Tristan da Cunha Gelidium (Gelidiales, Rhodophyta) species

2020 ◽  
Vol 63 (5) ◽  
pp. 455-462
Author(s):  
D. Wilson Freshwater ◽  
Sue Scott ◽  
Enrico M. Tronchin ◽  
Gary W. Saunders
Keyword(s):  
Southern Africa ◽  
Endemic Species ◽  
Red Algae ◽  
Genetic Group ◽  
The Third ◽  
Tristan Da Cunha

AbstractThree endemic species of Gelidium have been described from the remote Tristan da Cunha archipelago. A recent barcode survey of Tristan da Cunha red algae in combination with the clarification of vouchers for previously sequenced specimens has prompted a molecular and morphological reassessment of these species. Analyses of rbcL and COI-5P data indicated that all sequenced Tristan da Cunha specimens represented a single taxon, and furthermore that this genetic group was conspecific with Gelidium micropterum from southern Africa. Morphologically the Tristan da Cunha specimens represented either Gelidium concinnum or Gelidium regulare, and there was a grade of character states between both of these species, as well as G. micropterum. Based on these results the synonymy of G. concinnum and G. regulare under G. micropterum is proposed and an expanded description of G. micropterum provided. None of the studied Tristan da Cunha specimens clearly fit the description of the third endemic species, Gelidium inflexum, and its status could not be determined.

scholarly journals Genetic variability in natural populations of Zeyheria montana mart. from the Brazilian Cerrado

2007 ◽  
Vol 64 (4) ◽  
pp. 409-415 ◽  
Author(s):  
Bianca Waléria Bertoni ◽  
Spartaco Astolfi Filho ◽  
Ernani Ronie Martins ◽  
Carlos Ferreira Damião Filho ◽  
Suzelei de Castro França ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Natural Populations ◽  
Mantel Test ◽  
Scientific Data ◽  
Group Method ◽  
Polymorphism Analysis ◽  
Popular Medicine ◽  
Pair Group ◽  
Optimized Protocol ◽  
Geographical Distances

Zeyheria montana, an endemic species of the Bignoniaceae family from the Brazilian Cerrado's known for its anti-cancer properties, is widely used as imuno stimulant in the popular medicine and its therapeutic activity must be validated by scientific data. The objective of this work was to evaluate the genetic variability of eight plant populations collected within the state of São Paulo, Brazil, via Random Amplification of Polymorphic DNA (RAPD) used as molecular markers. After an optimized protocol for the amplification reaction, nine selected primers generated 105 reproducible bands, indicating up to 60% polymorphism. Analysis of molecular variance (AMOVA) revealed higher genetic variation within populations (84.03%) than among populations (15.97%). The variation values estimated by phiST (0.160) indicated moderate to high inter population structuration. Levels of similarity inter plants with genetic and geographical distances, estimated by the unweighted pair-group method analysis (UPGMA) clustering and non-metric multidimensional scaling (NMDS) ordination methods and by the Mantel test (-0.2345 p = 0.118) denoted that the structure found follows the island model, which assumes that a single population of infinite size may have initiated the existing populations of Zeyheria montana, with no spatial position correlation. Based on the obtained data, a germplasm bank from individuals representing the species variability was established. Furthermore the information here reported can be of importance to develop strategies for the conservation of Z. montana.

Extensive hybridization between two Andean warbler species with shallow divergence in mtDNA

The Auk ◽  
2021 ◽  
Vol 138 (1) ◽  
Author(s):  
Laura N Céspedes-Arias ◽  
Andrés M Cuervo ◽  
Elisa Bonaccorso ◽  
Marialejandra Castro-Farias ◽  
Alejandro Mendoza-Santacruz ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Contact Zone ◽  
Hybrid Zone ◽  
Secondary Contact ◽  
Tropical Andes ◽  
Phenotypic Data ◽  
Geographic Ranges ◽  
Intermediate Phenotypes ◽  
Ecological Barriers

Abstract Studying processes acting on differentiated populations upon secondary contact, such as hybridization, is important to comprehensively understand how species are formed and maintained over time. However, avian speciation studies in the tropical Andes have largely focused on the role of topographic and ecological barriers promoting divergence in allopatry, seldom examining hybridization and introgression. We describe a hybrid zone involving 2 closely related Andean warblers (Parulidae), the Golden-fronted Redstart (Myioborus ornatus), and the Spectacled Redstart (Myioborus melanocephalus). Geographic ranges of these species abut near the Colombia-Ecuador border and many specimens from the region exhibit intermediate phenotypes, but a formal description of phenotypic variation in the contact zone was heretofore lacking. We collected specimens across a transect encompassing the area where ranges abut and areas where only “pure” parental phenotypes of M. ornatus chrysops and M. melanocephalus ruficoronatus occur. We described variation in plumage traits including patterns of head and ventral coloration and tail markings based on 321 specimens. To describe genetic variation in the contact zone and over a broader phylogeographic context, we used sequences of the mitochondrial ND2 gene for 219 individuals across the transect and the entire range of both species, including all subspecies, from Venezuela to Bolivia. We documented a hybrid zone ~200 km wide based on head coloration, where intermediate plumage phenotypes are most common and “pure” forms do not overlap geographically, consistent with extensive hybridization. Across the range of the M. ornatus–M. melanocephalus complex, mitochondrial genetic structure was shallow, with genetic breaks only coinciding clearly with one topographic feature. Such a low genetic structure is striking given the high diversity in plumage phenotypes and the current taxonomy of the group. Our phenotypic data suggest that barriers to hybridization are not strong, and allow us to postulate hypotheses to be tested using forthcoming genomic data.

Multiple visits of individual humpback whales (Megaptera novaeangliae) between the Hawaiian and Japanese winter grounds

1999 ◽  
Vol 77 (3) ◽  
pp. 504-508 ◽  
Author(s):  
Dan R Salden ◽  
Louis M Herman ◽  
Manami Yamaguchi ◽  
Fumihiko Sato
Keyword(s):  
Genetic Variability ◽  
North Pacific ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Winter Ground ◽  
The Third ◽  
Breeding Populations ◽  
Published Report

We document through photographic identifications three humpback whale (Megaptera novaeangliae) winter ground interchanges between Hawai'i and Japan. Two of these whales, identified as male by their behavioral roles, made multiple interchanges across years; i.e., they were initially seen in Hawai'i, were later observed in Japan, and subsequently, returned to Hawai'i. The third whale was seen in only 2 different years, once in Japan and then in Hawai'i. Prior to this report, there has been only one published report of a Hawai'i-Japan interchange and only eight between Hawai'i and Mexico. None of these involved multiple interchanges. The current findings demonstrate that individual whales may be highly flexible in their annual choice of widely separated winter destinations and suggest that these wanderers may be mainly males. The occurrence of wanderers provides a mechanism for increasing genetic variability in the breeding populations and also suggests a mechanism for noted song similarities across different North Pacific winter grounds.

scholarly journals A parapagus dicephalus tripus tribrachius conjoined twin with a unique morphological pattern: a case report

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Jeske F. M. Bovendeert ◽  
Rutger A. J. Nievelstein ◽  
Ronald L. A. W. Bleys ◽  
Cindy G. J. Cleypool
Keyword(s):  
Case Report ◽  
Congenital Malformation ◽  
Medical Center ◽  
Conjoined Twins ◽  
Lower Limbs ◽  
Whole Body ◽  
Radiological Imaging ◽  
Morphological Pattern ◽  
The Third ◽  
Macroscopic Examination

Abstract Background Conjoined twinning is a rare congenital malformation with an incidence of about 1.5 per 100,000 births. Because no consensus has been reached regarding the dysmorphology, thorough descriptions of conjoined twins as part of teratological collections can be useful to increase knowledge of this congenital malformation. In this case report, we describe a parapagus dicephalus twin from the collection of the Department of Anatomy of the University Medical Center Utrecht in the Netherlands. External anatomical characteristics were assessed through a detailed macroscopic examination and internal characteristics by means of whole-body computed tomography and magnetic resonance imaging (3 Tesla). Case presentation Macroscopic examination showed a Caucasian male parapagus dicephalus tripus tribrachius conjoined twin a type of conjoined twinning in which there are two heads side by side, one rump, and three upper and three lower limbs. In addition, anencephaly was observed in the left twin. Radiological imaging showed a normal central nervous system in the right twin and absence of the calvaria, cerebrum, diencephalon, and mesencephalon in the left twin. There was clear duplication of the vertebral column, rib cage, respiratory system, and gastrointestinal system at least up to and including the first part of the duodenum. The heart consisted of a monoatrium with two separate ventricles. There was a fused liver with a single gallbladder, a single spleen, three kidneys, two bladders, and duplication of the penis. The third upper and lower extremities were articulating with a fused glenoid and acetabulum, respectively. The third foot showed both polydactyly and syndactyly of the toes. Conclusion This case report describes a unique case of a male dicephalus parapagus tripus tribrachus conjoined twin discordant for anencephaly. Radiological imaging proved to be an adequate noninvasive method to provide insights into the internal (dys)morphology of this specific specimen, improving its scientific and educational value. This approach could be generally applied to other teratological specimens, thereby strengthening arguments regarding pathogenetic hypotheses, which may lead to new or improved insights into both normal and abnormal embryonic development.

scholarly journals Hybrid zone formation and contrasting outcomes of secondary contact over transects in common toads

2017 ◽  
Vol 26 (20) ◽  
pp. 5663-5675 ◽  
Author(s):  
Jan W. Arntzen ◽  
Wouter de Vries ◽  
Daniele Canestrelli ◽  
Iñigo Martínez-Solano
Keyword(s):  
Hybrid Zone ◽  
Secondary Contact ◽  
Zone Formation

scholarly journals Influence of photoperiod on vegetation phases and tuber development in topinambour (Helianthus tuberosus L.)

2012 ◽  
Vol 64 (1) ◽  
pp. 175-182 ◽  
Author(s):  
S. Terzic ◽  
Jovanka Atlagic ◽  
Ivana Maksimovic ◽  
Tijana Zeremski ◽  
Sofija Petrovic ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Opposite Effect ◽  
The Other ◽  
Day Length ◽  
Helianthus Tuberosus ◽  
Length Of Day ◽  
Tuber Development ◽  
Vegetative Phase ◽  
Photoperiodic Control ◽  
The Third

A topinambour collection was analyzed to determine the genetic variability of 141 accessions in reaction to the length of day (light), its influence on vegetative and flowering phases, tuber number and mass. Day length significantly influenced flowering, which started with the first shorter days (15.6 h) in the third decade of June, while the majority of accessions flowered in the third decade of August (13.3 h). Differences between accessions were statistically significant for the analyzed phenotype traits. A significantly longer vegetative phase was found in Montenegrin accessions in comparison to the other groups of origin. Duration of the vegetative phase was significantly and positively correlated to tuber mass and negatively to their number, while duration of the reproductive phase had an opposite effect. For further work on topinambour breeding, it would be important to describe the mechanism of photoperiodic control of flowering initialization. Only by obtaining accessions neutral to the photoperiod could topinambour become a cultivated crop.

scholarly journals Taming, Domestication and Exaptation: Trajectories of Transposable Elements in Genomes

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3590
Author(s):  
Pierre Capy
Keyword(s):  
Genetic Variability ◽  
Transposable Elements ◽  
Environmental Constraints ◽  
The Third ◽  
Evolutionary Trajectories ◽  
Pass Through ◽  
Horizontal Transfers ◽  
Population Fitness

During evolution, several types of sequences pass through genomes. Along with mutations and internal genetic tinkering, they are a useful source of genetic variability for adaptation and evolution. Most of these sequences are acquired by horizontal transfers (HT), but some of them may come from the genomes themselves. If they are not lost or eliminated quickly, they can be tamed, domesticated, or even exapted. Each of these processes results from a series of events, depending on the interactions between these sequences and the host genomes, but also on environmental constraints, through their impact on individuals or population fitness. After a brief reminder of the characteristics of each of these states (taming, domestication, exaptation), the evolutionary trajectories of these new or acquired sequences will be presented and discussed, emphasizing that they are not totally independent insofar as the first can constitute a step towards the second, and the second is another step towards the third.

scholarly journals Isozyme and RAPD studies in Prosopis glandulosa and P. Velutina (Leguminosae, Mimosoideae)

2000 ◽  
Vol 23 (3) ◽  
pp. 639-648 ◽  
Author(s):  
Cecilia Bessega ◽  
Beatriz O. Saidman ◽  
Juan C. Vilardi
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Rapd Markers ◽  
Random Amplified Polymorphic Dna ◽  
Mantel Test ◽  
Prosopis Glandulosa ◽  
Geographical Distance ◽  
Taxonomic Studies

Allozyme and random amplified polymorphic DNA (RAPD) techniques have been compared for their usefulness for genetic and taxonomic studies in Prosopis glandulosa and P. velutina populations. Isozymes and RAPDs yielded similarly high estimates of genetic variability. Genetic structure and differentiation were analyzed through non-hierarchical Wright's F DT. For all populations considered, both markers produced low gene flow (Nm < 1) estimates. When only P. glandulosa populations were analyzed, isozyme data yielded higher gene flow estimates (Nm > 1), in agreement with that expected for conspecific populations. However, in RAPD data the expected reduction in F DT and the increase in Nm were not observed. Correlation between F DT and geographical distance matrices (Mantel test) for all populations was significant (P = 0.02) when based on isozymes, but not so (P = 0.33) when based on RAPDs. No significant associations among genetic and geographical or climatic variables were observed. Two isoenzyme systems (GOT and PRX) enabled us to distinguish between P. glandulosa and P. velutina, but no diagnostic band for recognition of populations or species studied here were detected by RAPD. However, RAPD markers showed higher values for genetic differentiation among conspecific populations of P. glandulosa and a lower coefficient of variation than those obtained from isozymes.

How often do they do it? An in-depth analysis of the hybrid zone of two grass snake species (Natrix astreptophora and Natrix helvetica)

2020 ◽  
Vol 131 (4) ◽  
pp. 756-773
Author(s):  
Marika Asztalos ◽  
Nadine Schultze ◽  
Flora Ihlow ◽  
Philippe Geniez ◽  
Matthieu Berroneau ◽  
...  
Keyword(s):  
Contact Zone ◽  
Hybrid Zone ◽  
Climatic Conditions ◽  
Secondary Contact ◽  
Distribution Models ◽  
Long Distance ◽  
Depth Analysis ◽  
Grass Snake ◽  
Genetic Signatures ◽  
Cline Width

Abstract We examined the contact zone of two parapatric species of grass snake (Natrix astreptophora and Natrix helvetica) in southern France. To this end, we used comprehensive sampling, analysed mtDNA sequences and microsatellite loci, and built Species Distribution Models for current and past climatic conditions. The contact zone had established by the mid-Holocene during range expansions from glacial refuges in the Iberian Peninsula (N. astreptophora) and southern or western France (N. helvetica). The contact zone represents a narrow bimodal hybrid zone, with steep genetic transition from one taxon to the other and rare hybridization, supporting species status for N. astreptophora and N. helvetica. Our results suggest that the steepness of the clines is a more robust tool for species delimitation than cline width. In addition, we discovered in western France, beyond the hybrid zone, a remote population of N. helvetica with genetic signatures of hybridization with N. astreptophora, most likely the result of human-mediated long-distance dispersal. For N. helvetica, we identified a southern and a northern population cluster, connected by broad-scale gene flow in a unimodal hybrid zone running across France. This pattern either reflects genetic divergence caused by allopatry in two microrefuges and subsequent secondary contact or introgression of foreign alleles into the southern cluster.

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