scholarly journals Parallel changes in mate-attracting calls and female preferences in autotriploid tree frogs

2011 ◽  
Vol 279 (1733) ◽  
pp. 1583-1587 ◽  
Author(s):  
Mitch A. Tucker ◽  
H. C. Gerhardt
Keyword(s):  
Pulse Rate ◽  
Parental Species ◽  
Diploid Species ◽  
Sympatric Speciation ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Female Preferences ◽  
The Mean ◽  
Tree Frogs ◽  
Different Origins

For polyploid species to persist, they must be reproductively isolated from their diploid parental species, which coexist at the same time and place at least initially. In a complex of biparentally reproducing tetraploid and diploid tree frogs in North America, selective phonotaxis—mediated by differences in the pulse-repetition (pulse rate) of their mate-attracting vocalizations—ensures assortative mating. We show that artificially produced autotriploid females of the diploid species ( Hyla chrysoscelis ) show a shift in pulse-rate preference in the direction of the pulse rate produced by males of the tetraploid species ( Hyla versicolor ). The estimated preference function is centred near the mean pulse rate of the calls of artificially produced male autotriploids. Such a parallel shift, which is caused by polyploidy per se and whose magnitude is expected to be greater in autotetraploids, may have facilitated sympatric speciation by promoting reproductive isolation of the initially formed polyploids from their diploid parental forms. This process also helps to explain why tetraploid lineages with different origins have similar advertisement calls and freely interbreed.

CYTOGENETIC STUDIES IN AMARANTHUS: II. NATURAL INTERSPECIFIC HYBRIDIZATION BETWEEN AMARANTHUS DUBIUS AND A. SPINOSUS

1959 ◽  
Vol 37 (5) ◽  
pp. 1063-1070 ◽  
Author(s):  
William F. Grant
Keyword(s):  
Chromosome Number ◽  
Parental Species ◽  
Diploid Species ◽  
Gene Exchange ◽  
Stomatal Size ◽  
Amaranthus Spinosus ◽  
Cytogenetic Studies ◽  
Mean Size ◽  
Pollen Grain Size ◽  
The Mean

Spontaneous triploid hybrids (2n = 49) were discovered between Amaranthus spinosus L. (2n = 34), a diploid species, and A. dubius Mart. ex Thellung (2n = 64) which was found to be a tetraploid. Meiosis in the hybrids was irregular and 15 univalents were most frequently found along with the bivalents pairing apparently allosyndetically (15 I's + 17 II's = 2n = 49) at metaphase I. Univalents were excluded from the telophase nuclei in both meiotic divisions resulting in supernumerary microspores and in a reduction in the mean size of the microspores. Consequently, the triploids were largely sterile and the few undersized seeds produced failed to germinate. Seed weight, seed volume, stomatal size, and pollen grain size were proportional to chromosome number in the parents only, not in their hybrids. Since A. dubius exhibits typical bivalent behavior in synapsis, it is considered to be an allotetraploid in which A. spinosus has been one progenitor. It is suggested that the diploid A. quitensis H. B. K. (2n = 32) might be the other progenitor, but from chromosome number relationships and morphological considerations more than two species may be involved. As a result of the high sterility of the triploids, gene exchange between the parental species must be of a very limited nature.

Revisiting the evolution of the North American tetraploid treefrog (Hyla versicolor)

Genome ◽  
2020 ◽  
Vol 63 (11) ◽  
pp. 547-560 ◽  
Author(s):  
James P. Bogart ◽  
Patrick Burgess ◽  
Jinzhong Fu
Keyword(s):  
Diploid Species ◽  
Hyla Versicolor ◽  
Hyla Chrysoscelis ◽  
Gene Exchange ◽  
Tetraploid Species ◽  
Sympatric Populations ◽  
Female Progeny ◽  
The North ◽  
Mating Call ◽  
Mitochondrial Cytochrome B

Hyla chrysoscelis and H. versicolor are common treefrogs in eastern North America and are a cryptic diploid–tetraploid species pair. They are morphologically identical but H. versicolor is a tetraploid. They can be identified acoustically by the male’s advertisement mating call, which has a pulse repetition rate that has twice as many pulses per second in the diploid species, H. chrysoscelis. We used isozymes, microsatellite DNA alleles, and mitochondrial cytochrome b sequences to test the hypothesis that gene exchange occurs between the diploid and tetraploid species in sympatric populations. Each method provided results that are best explained by occasional hybridization of female H. versicolor and male H. chrysoscelis. We propose that H. versicolor first arose from an autotriploid H. chrysoscelis female that produced unreduced triploid eggs. After H. versicolor became established, genes could be passed from H. chrysoscelis to H. versicolor in sympatric populations when these species hybridize. Their F1 female progeny produce unreduced triploid eggs that are fertilized by haploid H. chrysoscelis sperm to reconstitute H. versicolor. Genes can be passed from diploid H. chrysoscelis to tetraploid H. versicolor in sympatric populations.

Developmental abnormalities in triploid hybrids between tetraploid and diploid tree frogs (genus Hyla)

1992 ◽  
Vol 70 (10) ◽  
pp. 2072-2076
Author(s):  
Barbara K. Mable ◽  
Leslie A. Rye
Keyword(s):  
Parental Species ◽  
Eye Development ◽  
Developmental Differences ◽  
Hyla Versicolor ◽  
Diploid Males ◽  
Cross Combination ◽  
Hyla Cinerea ◽  
Developmental Abnormalities ◽  
Tree Frogs ◽  
Eye Formation

Crosses between tetraploid female grey tree frogs, Hyla versicolor, and diploid males of the same genus may provide information on developmental differences between the parental species. Crosses with Hyla cinerea males in 1988 produced a large number of vigorous offspring, but abnormalities in eye development indicated some incompatibility of the parental genomes. The degree of eye development of the hybrids varied, ranging from completely absent to fully functional. Repetition of this cross combination in 1989 resulted in similar variation in eye formation. Histological sections through developing eyes indicated that the abnormalities may be related to improper formation of the cornea, improper orientation of the lens, or lack of lens induction. This may reflect differences in the timing of development between the two parental species.

Anisotropy of damage productions in electron irradiated molybdenum

1978 ◽  
Vol 36 (1) ◽  
pp. 354-355
Author(s):  
K. Izui ◽  
S. Furuno ◽  
H. Otsu ◽  
T. Nishida ◽  
H. Maeta
Keyword(s):  
Electron Flux ◽  
Threshold Energy ◽  
High Energy ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
Displacement Threshold ◽  
The Mean ◽  
Channeling Effect ◽  
Different Origins ◽  
Threshold Energies

Anisotropy of damage productions in crystals due to high energy electron bombardment are caused from two different origins. One is an anisotropic displacement threshold energy, and the other is an anisotropic distribution of electron flux near the atomic rows in crystals due to the electron channeling effect. By the n-beam dynamical calculations for germanium and molybdenum we have shown that electron flux at the atomic positions are from ∽4 to ∽7 times larger than the mean incident flux for the principal zone axis directions of incident 1 MeV electron beams, and concluded that such a locally increased electron flux results in an enhanced damage production. The present paper reports the experimental evidence for the enhanced damage production due to the locally increased electron flux and also the results of measurements of the displacement threshold energies for the <100>,<110> and <111> directions in molybdenum crystals by using a high voltage electron microscope.

scholarly journals Population structure of Chinese southwest wheat germplasms resistant to stripe rust and powdery mildew using the DArT-seq technique

2018 ◽  
Vol 48 (4) ◽  
Author(s):  
Tianqing Chen ◽  
Piyada Alisha Tantasawat ◽  
Wei Wang ◽  
Xu Gao ◽  
Liyi Zhang
Keyword(s):  
Population Structure ◽  
Disease Resistance ◽  
Polymorphic Information Content ◽  
Wheat Breeding ◽  
Wheat Varieties ◽  
Group I ◽  
Population Structure Analysis ◽  
Specific Allele ◽  
The Mean ◽  
Different Origins

ABSTRACT: Understanding genetic variability in existing wheat accessions is critical for collection, conservation and use of wheat germplasms. In this study, 138 Chinese southwest wheat accessions were investigated by genotyping using two resistance gene makers (Pm21 and Yr26) and DArT-seq technique. Finally, about 50% cultivars (lines) amplified the specific allele for the Yr26 gene (Gwm11) and 40.6% for the Pm21 gene (SCAR1265). By DArT-seq analysis, 30,485 markers (6486 SNPs and 23999 DArTs) were obtained with mean polymorphic information content (PIC) value 0.33 and 0.28 for DArT and SNP marker, respectively. The mean Dice genetic similarity coefficient (GS) was 0.72. Two consistent groups of wheat varieties were identified using principal coordinate analysis (PCoA) at the level of both the chromosome 6AS and the whole-genome, respectively. Group I was composed of non-6VS/6AL translocation lines of different origins, while Group II was composed of 6VS/6AL translocation (T6VS/6AL) lines, most of which carried the Yr26 and Pm21 genes and originated from Guizhou. Besides, a model-based population structure analysis revealed extensive admixture and further divided these wheat accessions into six subgroups (SG1, SG2, SG3, SG4, SG5 and SG6), based on their origin, pedigree or disease resistance. This information is useful for wheat breeding in southwestern China and association mapping for disease resistance using these wheat germplasms in future.

scholarly journals Searching for a kinematic signature of the moderately metal-poor stars in the Milky Way bulge using N-body simulations

2018 ◽  
Vol 615 ◽  
pp. A100 ◽  
Author(s):  
A. Gómez ◽  
P. Di Matteo ◽  
M. Schultheis ◽  
F. Fragkoudi ◽  
M. Haywood ◽  
...  
Keyword(s):  
Milky Way ◽  
Thin Disk ◽  
Secular Evolution ◽  
Thick Disc ◽  
Thin Disc ◽  
The Mean ◽  
The Difference ◽  
Different Origins ◽  
Argos Data ◽  
Internal Evolution

Although there is consensus that metal-rich stars in the Milky Way bulge are formed via secular evolution of the thin disc, the origin of their metal-poor counterparts is still under debate. Two different origins have been invoked for metal-poor stars: they might be classical bulge stars or stars formed via internal evolution of a massive thick disc. We use N-body simulations to calculate the kinematic signature given by the difference in the mean Galactocentric radial velocity (ΔVGC) between metal-rich stars ([Fe/H] ≥ 0) and moderately metal-poor stars (–1.0 ≤ [Fe/H] < 0) in two models, one containing a thin disc and a small classical bulge (B/D = 0.1), and the other containing a thin disc and a massive centrally concentrated thick disc. We reasonably assume that thin-disk stars in each model may be considered as a proxy of metal-rich stars. Similarly, bulge stars and thick-disc stars may be considered as a proxy of metal-poor stars. We calculate ΔVGC at different latitudes (b = 0°, − 2°, − 4°, − 6°, − 8° and − 10°) and longitudes (l = 0°, ± 5°, ± 10° and ± 15°) and show that the ΔVGC trends predicted by the two models are different. We compare the predicted results with ARGOS data and APOGEE DR13 data and show that moderately metal-poor stars are well reproduced with the co-spatial stellar discs model, which has a massive thick disc. Our results give more evidence against the scenario that most of the metal-poor stars are classical bulge stars. If classical bulge stars exists, most of them probably have metallicities [Fe/H] < –1 dex, and their contribution to the mass of the bulge should be a small percentage of the total bulge mass.

scholarly journals Hepatica transsilvanica Fuss (Ranunculaceae) is an Allotetraploid Relict of the Tertiary Flora in Europe – Molecular Phylogenetic Evidence

2020 ◽  
Vol 89 (3) ◽  
Author(s):  
Levente Laczkó ◽  
Gábor Sramkó
Keyword(s):  
Parental Species ◽  
Gene Tree ◽  
Diploid Species ◽  
Nuclear Gene ◽  
Hybrid Origin ◽  
Distribution Area ◽  
Recent Common Ancestor ◽  
Term Survival ◽  
Quaternary Glaciation ◽  
Eastern Carpathians

The <em>Hepatica </em>section <em>Angulosa </em>consists of mainly tetraploid (2<em>n </em>= 28) species that are distributed disjunctly throughout Eurasia. Karyological evidence proves the hybrid origin of the polyploid species of this section. <em>Hepatica transsilvanica </em>is a member of this species group with a conspicuous distribution restricted to the Eastern Carpathians. Based on genome size and cytotypes, the paternal parent of <em>H. transsilvanica </em>is described to be the only diploid species in section <em>Angulosa</em>, <em>H. falconeri</em>. The maternal species is hypothesized to be <em>H. nobilis</em>, a European species with entirely lobed leaves and a wider distribution area. Although the hybrid origin of <em>H. transsilvanica </em>is well documented by karyological evidence, the time of hybridization has never been studied. By using sequences of both the nuclear and plastid genome, we reconstructed the phylogenetic relationships and divergence times of <em>H. transsilvanica </em>and its parental species. The identity of the parental species is corroborated by discordant gene tree topologies of the nrITS and plastid sequences. Moreover, both gene copies of the parental species could be identified with the low-copy nuclear gene, <em>MLH1</em>. Divergence dating analysis using Bayesian phylogenetic methods strongly supported the long-term survival of <em>H. transsilvanica </em>in the Southeastern Carpathians, as the most recent common ancestor of the hybrid and parent species existed not later than the beginning of the Pleistocene, ca. 3 million years ago. These results not only highlight the biogeographic importance of the Southeastern Carpathians in the Quaternary glaciation periods, but also emphasize that Tertiary lineages could have survived in a Central European cryptic refugium.

A New Noninvasive Method to Measure Blood Pressure 

1999 ◽  
Vol 91 (3) ◽  
pp. 686-686 ◽  
Author(s):  
Kumar Belani ◽  
Makoto Ozaki ◽  
James Hynson ◽  
Thomas Hartmann ◽  
Hugo Reyford ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Critically Ill ◽  
Radial Artery ◽  
Pulse Rate ◽  
Critically Ill Patients ◽  
Arterial Catheter ◽  
Arterial Waveform ◽  
Measure Blood Pressure ◽  
The Mean ◽  
Radial Artery Catheter

Background Blood pressure (BP) monitoring with arterial waveform display requires an arterial cannula. We evaluated a new noninvasive device, Vasotrac (Medwave, Arden Hills, MN) that provides BP measurements approximately every 12-15 beats and displays pulse rate and a calibrated arterial waveform for each BP measurement. Methods Surgical and critically ill patients (n = 80) served as subjects for the study. BPs, pulse waveforms, and pulse rates measured via a radial artery catheter were compared with those obtained by the Vasotrac from the opposite radial artery. Data were analyzed to determine agreement between the two systems of measurement. Results Blood pressure measured noninvasively by the Vasotrac demonstrated excellent correlation (P&lt;0.01) with BP measured via a radial arterial catheter (systolic r2 = 0.93; diastolic r2 = 0.89; mean r2 = 0.95). Differences in BP measured by the Vasotrac versus the radial arterial catheter were small. The mean+/-SD bias and precision were as follows: systolic BP 0.02+/-5.4 mm Hg and 3.9+/-3.7 mm Hg; diastolic BP -0.39+/-3.9 mm Hg and 2.7+/-2.8 mm Hg; mean BP -0.21+/-3.0 mm Hg and 2.1+/-2.2 mm Hg compared with radial artery measurements. The Vasotrac pulse rates were almost identical to those measured directly (r2 = 0.95). The Vasotrac BP waveform resembled those directly obtained radial artery pulsatile waveforms. Conclusions In surgical and critically ill patients, the Vasotrac measured BP, pulse rate, and displayed radial artery waveform, which was similar to direct radial arterial measurements. It should be a suitable device to measure BP frequently in a noninvasive fashion.

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