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1.
Dalius Butkauskas Saulius Švažas Vaida Tubelytė Julius Morkūnas Aniolas Sruoga Dmitrijs Boiko Algimantas Paulauskas Vitas Stanevičius Vykintas Baublys 《Central European Journal of Biology》2012,7(5):886-894
Two closely related swan species, the mute swan Cygnus olor and the whooper swan Cygnus cygnus, were formerly allopatric throughout their breeding ranges, but during the last decades a sympatric distribution has become characteristic of these species in the Baltic Sea region. The whooper swan has gradually replaced the mute swan in many suitable habitats in Lithuania and Latvia. Marked differences in the genetic population structure of both species may partially explain the dominance of the whooper swan, as genetic population divergence can be a major factor affecting inter-specific competition. A homogenous genetic population structure was defined for mute swans breeding in Lithuania, Latvia, Poland and Belarus. Breeding mute swans in this region are mostly of naturalised origin. A diverse population genetic structure characterizes whooper swans breeding in Lithuania and Latvia. 相似文献
2.
Chelsea L. Teale 《Biological invasions》2011,13(8):1729-1733
The success or failure of species introductions is linked to their location, date, size, and frequency. However, reliance
on synthetic works to identify and quantify these factors can lead to errors if original sources are misinterpreted or misquoted.
Furthermore, information cannot be verified if authors fail to cite their sources and repetition may lead to compounded errors
that have implications for studies of invasion patterns and processes. Naturalized populations of mute swans (Cygnus olor) in the Atlantic Flyway, for example, are repeatedly attributed to two large introductions in New York State. Tracing this
belief back to original reports and using additional historical records, this inquiry investigates the first introductions
of mute swans in New York State and presents evidence for three initial sites. Newspapers are also recommended as a newly
searchable archive of species introduction records. 相似文献
3.
4.
Quantitative trait loci (QTL) detection was carried out for adventitious rooting and associated propagation traits in a second-generation
outbred Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid family (n = 186). The parental species of this cross are divergent in their capacity to develop roots adventitiously on stem cuttings
and their propensity to form lignotubers. For the ten traits studied, there was one or two QTL detected, with some QTL explaining
large amounts of phenotypic variation (e.g. 66% for one QTL for percentage rooting), suggesting that major effects influence
rooting in this cross. Collocation of QTL for many strongly genetically correlated rooting traits to a single region on linkage
group 12 suggested pleiotropy. A three locus model was most parsimonious for linkage group 12, however, as differences in
QTL position and lower genetic correlations suggested separate loci for each of the traits of shoot production and root initiation.
Species differences were thought to be the major source of phenotypic variation for some rooting rate and root quality traits
because of the major QTL effects and up to 59-fold larger homospecific deviations (attributed to species differences) relative
to heterospecific deviations (attributed to standing variation within species) evident at some QTL for these traits. A large
homospecific/heterospecific ratio at major QTL suggested that the gene action evident in one cross may be indicative of gene
action more broadly in hybrids between these species for some traits. 相似文献
5.
L. B. Oknina O. A. Kuznetsova A. P. Belostotskyi N. L. Nechaeva E. V. Kutakova E. L. Masherow A. S. Romanov 《Human physiology》2011,37(1):49-56
The aim of the study was to trace the cumulative changes in the amplitude-time parameters of the AEP (acoustic evoked potential)
components N1, N2, and P300 in the experimental situations of different complexities (counting and listening to sounds) and to compare the differences
between young and mature subjects. The AEP was recorded in 12 healthy subjects aged 18 to 22 years and in 12 subjects aged
32 to 59 years. It was revealed that the components N1, N2, and P300 recorded in the situation of listening without any preliminary instruction did not differ in young and mature individuals.
In the younger subjects, a higher N1 amplitude was revealed when they counted sounds, compared to listening, whereas the latency values of this component did
not differ, irrespective of the complexity of the task. The component N2 was shown to demonstrate latency stability in relation to the age and the experimental situation. The N2 amplitude was higher in the situation of counting sounds in both age groups. The amplitude-time parameters of P300 did not differ in subjects of different ages in the listening task. The features of the components N1, N2, and P300 revealed in young and mature subjects in the experimental situations differing in complexity lead us to suggest that,
with age, humans develop adaptive mechanisms contributing to successful task performance. 相似文献
6.
Michael G. Boegle Susanne Schneider Beate Mannschreck Arnulf Melzer 《Hydrobiologia》2007,586(1):155-166
7.
Molecular tools were used to evaluate the hybrid status of a specimen with intermediate colour pattern between Halichoeres bivittatus and Halichoeres garnoti from Belize. Phylogenetic analyses of the two species, eight Halichoeres species from new and old world lineages and two outgroups showed that the study species are closely related and that H. garnoti is the maternal contributor to the putative hybrid specimen, based on partial mitochondrial COI data. Direct sequencing of
Intron 1 of the nuclear ribosomal protein S7 identified H. bivittatus as sister to H. garnoti with the putative hybrid specimen in an intermediate position, due to heterozygosity at nucleotides alternatively fixed in
the two putative parent species. This is consistent with the hybrid status of the specimen, with parental contributions from
both H. garnoti and H. bivittatus. These results, combined with no evidence of introgression between the two parent species (based on the mtDNA and the single
investigated nuclear marker) and the biogeography and ecology of these species suggests that this is a rare event with minimal
evolutionary implications. 相似文献
8.
Background
The MC1R (melanocortin-1 receptor) locus underlies intraspecific variation in melanin-based dark plumage coloration in several unrelated birds with plumage polymorphisms. There is far less evidence for functional variants of MC1R being involved in interspecific variation, in which spurious genotype-phenotype associations arising through population history are a far greater problem than in intraspecific studies. We investigated the relationship between MC1R variation and plumage coloration in swans (Cygnus), which show extreme variation in melanic plumage phenotypes among species (white to black). 相似文献9.
I. Rosario G. Soro S. Déniz O. Ferrer F. Acosta D. Padilla B. Acosta 《Mycopathologia》2010,169(4):315-319
Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts
in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of
Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this
disease. 相似文献
10.
Anamélia de Souza Jesus Hugo Eduardo Schunemann Jackson Müller Moira Ansolch da Silva Júlio César Bicca-Marques 《Primates; journal of primatology》2010,51(3):227-230
Hybridization between Alouatta spp. has been suggested at contact zones of A. palliata and A. pigra in Mexico and of A. caraya and A. guariba clamitans in Brazil and Argentina. Whereas genetic data confirmed hybridization between the former pair of species, hybrid individuals
of the latter pair have been putatively identified on the basis of a mosaic pelage color. In this paper, we describe the first
confirmed cases of hybridization between a female A. guariba clamitans and a male A. caraya. One hybrid male was born in 2007 and one hybrid female was born in 2009 with distinct coat colors. The male resembled the
newborn color pattern characteristic of A. guariba clamitans, whereas the female resembled the newborn pattern of A. caraya. The birth and survival of the male hybrid for a year and a half indicated the viability of the heterogametic sex. 相似文献
11.
Wang Minqin Zhao Junsheng Peng Zhenying Guo Wei Wang Yun Wang Le Xia Guangmin 《Plant Cell, Tissue and Organ Culture》2008,92(2):121-130
In order to investigate chromosome elimination in symmetric somatic hybridization between Bupleurum scorzonerifolium and Arabidopsis thaliana, protoplasts were isolated from suspension cultures of both A. thaliana and B. scorzonerifolium parents. Biparental protoplasts were mixed at a rate of 1.5:1 and fused with PEG-method. After protoplast fusion, the products
were cultured in the P5 liquid medium for microcallus formation. Single cell lines formed from microcalli after subculturing
on the MB1 (Xia and Chen, Plant Sci 120:197–203, 1996) solid medium. The putative somatic hybrid cell lines were identified
by cytological and molecular analysis. Of the 132 somatic cell lines generated, 16 were identified as somatic hybrids, with
the phenotypes resembled B. scorzonerifolium parent. These hybrids showed a complete set of B. scorzonerifolium chromosome and 0–2 small chromosome(s) of A. thaliana. A few of them showed nuclear and cytoplasmic SSR fragments of A. thaliana. These hybrid cell lines could differentiate to green spots, buds/leaves through complementation of regeneration ability.
The chromosomes elimination of A. thaliana was discussed.
Wang Minqin and Zhao Junsheng contributed equally to the work. 相似文献
12.
Luciano Elias Oliveira Kátia G. Facure Ariovaldo A. Giaretta 《Environmental Biology of Fishes》2012,93(1):89-94
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR)
in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the
number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration
of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic
by negatively affecting its density. 相似文献
13.
E. D. Badaeva O. Yu. Shelukhina O. S. Dedkova I. G. Loskutov V. A. Pukhalskyi 《Russian Journal of Genetics》2011,47(6):691-702
Using C-banding method and in situ hybridizatiion with the 45S and 5S rRNA gene probes, six hexaploid species of the genus
Avena L. with the ACD genome constitution were studied to reveal evolutionary karyotypic changes. Similarity in the C-banding patterns
of chromosomal patterns and in the patterns of distribution of the rRNA gene families suggests a common origin of all hexaploid
species. Avena fatua is characterized by the broadest intraspecific variation of the karyotype; this species displays chromosomal variants typical
of other hexaploid species of Avena. For instance, a translocation with the involvement of chromosome 5C marking A. occidentalis was discovered in many A. fatua accessions, whereas in other representatives of this species this chromosome is highly similar to the chromosome of A. sterilis. Only A. fatua and A. sativa show slight changes in the morphology and in the C-banding pattern of patterns of chromosome 2C. These results can be explained
either by a hybrid origin of A. fatua or by the fact that this species is an intermediate evolutionary form of hexaploid oats. The 7C–17 translocation was identified
in all studied accessions of wild and weedy species (A. sterilis, A. fatua, A. ludoviciana, and A. occidentalis) and in most A. sativa cultivars, but it was absent in A. byzantina and in two accessions of A. sativa. The origin and evolution of the Avena hexaploid species are discussed in context of the results. 相似文献
14.
ITS sequences determined for 53 Erysiphe specimens on Syringa and Ligustrum collected in Europe, East Asia, and North and South America were divided into two ITS groups, S and K types. Phylogenetic
analysis showed that these two ITS types do not share a common ancestor and form separate clades. The K type on Ligustrum was identified as Erysiphe ligustri based on the three-dimensional branching pattern of appendages. Morphological observations showed that there are some morphological
differences—pigmentation of appendages and number of ascospores per ascus—between the S and K types on Syringa. Based on these morphological observations, the S and K types on Syringa were identified as E. syringae and E. syringae-japonicae, respectively. The recent abundant production of chasmothecia by lilac powdery mildew in Europe was caused by E. syringae-japonicae introduced from East Asia. DNA sequence analyses of the rDNA ITS region and the 28S rDNA, tub2, CYP51, and Chs1 genes did not support an interspecific hybrid origin for E. syringae-japonicae. Haplotype analysis suggested that E. syringae originated in North America and independently migrated to East Asia and Europe/South America. 相似文献
15.
Julia C. Ruppell 《International journal of primatology》2010,31(1):73-94
Previous researchers suggested that gibbon song repertoire is genetically determined and song characteristics are useful for
assessing systematic relationships. The southern white-cheeked crested gibbon is regarded as either a subspecies of Nomascus leucogenys or its own species (Nomascus siki). I studied vocal diversity among different wild populations of Nomascus in central Vietnam and southern Laos to assess their taxonomic relationships and to examine whether their vocal patterns
correspond to forms previously described for Nomascus siki. I examined the songs of 7 Nomascus populations in Vietnam and Laos. I analyzed 192 song bouts from different gibbon groups including 173 phrases of 42 females
and 192 phrases of 42 males. Linear discriminant analysis, classification trees, and multidimensional scaling revealed marked
separation of groups in the northern and southern populations. Within the 2 geographic populations, there is little variability
and the vocal characteristics exhibited no apparent cline. I conclude that the northern and southern geographic populations
may represent 2 distinct taxa. I postulate that a taxonal boundary such as large rivers existing between southern Quang Binh
province and northern Thua-Thien Hue province in Vietnam and northern Phou Xang He NBCA and southern Dong Phou Vieng NBCA
in Laos has limited gene flow between the populations. Differing topographic features could also serve as a selective force
for improved sound transmission in a highly territorial species, driving the divergence between the 2 populations. 相似文献
16.
Bin Zhang DanDan Jiang WenWen Zhou HuaKun Hao TianGui Niu 《World journal of microbiology & biotechnology》2009,25(4):583-590
A new native feather-degrading bacterium has been isolated from the faeces of the agamid lizard Calotes versicolor, collected from the Beijing Zoo in China. The isolate, which has been identified as Bacillus sp. 50-3 based on morphological and biochemical and 16S rDNA tests, was shown to degrade native feather completely at 37°C
and pH 7.0 within 36 h when using chicken feathers as the sole carbon and nitrogen source. Bacillus sp. 50-3 presented optimum growth at 37°C and pH 7.0 in feather meal medium. Under these conditions, the maximum keratinase
activity (680 ± 25 U/ml) was also achieved. The keratinase of Bacillus sp. 50-3 was active over a broad range of pH values and temperatures toward azokeratin, and presented an optimum pH and temperature
of 10.0 and 60°C, respectively. Furthermore, it was relatively heat-and alkali-stable. Inhibitor studies showed that it seemed
to belong to the serine-metalloprotease type. Therefore, the enzyme from Bacillus sp. 50-3 is a novel, high alkaline keratinase, suggesting its potential use in biotechnological processes. 相似文献
17.
18.
Hydrogen exchange rates for backbone amide protons of oxidized Pseudomonas aeruginosa cytochrome c-551 (P. aeruginosa cytochrome c) have been measured in the presence of low concentrations of the denaturant guanidine hydrochloride. Analysis of the data
has allowed identification of submolecular unfolding units known as foldons. The highest-energy foldon bears similarity to
the proposed folding intermediate for P. aeruginosa cytochrome c. Parallels are seen to the foldons of the structurally homologous horse cytochrome c, although the heme axial methionine-bearing loop has greater local stability in P. aeruginosa cytochrome c, in accord with previous folding studies. Regions of low local stability are observed to correspond with regions that interact
with redox partners, providing a link between foldon properties and function.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Dmitar Lakušić 《Biologia》2008,63(5):631-636
The south-European Cardamine plumieri Vill. (sect. Pteroneurum subsect. Cryptopterum) is confirmed for the Flora of Serbia. Several populations were discovered in the central and western part of country, exclusively
on the serpentine bedrocks. Morphological, chorological and ecological characteristics of C. plumieri was studied. 相似文献
20.
Bacillus cereus C1L was demonstrated to induce systemic resistance in Lilium formosanum against leaf blight caused by Botrytis elliptica. Suppression subtractive hybridization library of L. formosanum triggered by B. cereus C1L were screened and 3 differentially expressed genes were identified. Based on sequence analysis, these genes encoding
putative glycine-rich protein, metallothionein-like protein, and PsbR protein of photosystem 2, were designated LfGRP1, LfMT1, and LfPsbR, respectively. The results of Northern blot analysis showed that expressions of LfGRP1, LfMT1 and LfPsbR increased in response to B. elliptica infection. On the other hand, expression of LfMT1 increased but expressions of LfGRP1 and LfPsbR decreased when the rhizosphere of L. formosanum was drenched with suspension of B. cereus C1L with or without subsequent challenge with B. elliptica on lily leaves. Similar expression profiles of homologues of LfGRP1, LfMT1, and LfPsbR (named LsGRP1, LsMT1, and LsPsbR, respectively) were presented in Lilium oriental hybrid Star Gazer. In addition, application of the photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea,
on the leaves reduced disease severity and expressions of LsGRP1 and LsPsbR just as that in response to B. cereus C1L treatment. 相似文献