排序方式: 共有56条查询结果,搜索用时 15 毫秒
1.
Distribution of haplotypes and microsatellite alleles among Asian elephants (<Emphasis Type="Italic">Elephas maximus</Emphasis>) in Thailand 总被引:1,自引:1,他引:0
Joerns Fickel Dietmar Lieckfeldt Parntep Ratanakorn Christian Pitra 《European Journal of Wildlife Research》2007,53(4):298-303
Habitat fragmentation often promotes increased inbreeding depression due to interrupted gene flow between populations. In
this study, we demonstrate that Asian elephants most likely also suffer from outbreeding depression due to cryptic speciation.
We analysed mitochondrial and nuclear DNA loci from 78 Asian elephants. Haplotype genealogy and analysis of molecular variance
revealed two matrilinear clades (α
h, β
h). Microsatellite analyses of individuals grouped according to their haplotype clade (corresponding group of nuclear genotypes
called α
nuc and β
nuc) revealed significant genotypic differentiation between α
nuc and β
nuc. Such genealogically differentiated forms in a morphologically uniform species are considered indicative of cryptic speciation.
The differentiation was caused by bulls, whereas considering cows only resulted in no differentiation. Such result is best
explained by Haldane’s rule whereby hybrid formation between genealogical forms causes lower viability and fertility of heterogametic hybrids. Although
the lack of hybrid-specific morphological characteristics renders direct testing of reduced hybrid fitness under natural conditions
unfeasible, the effects of Haldane’s rule are demonstrated by reduced male-mediated gene flow between genealogical forms under
sympatric conditions, as was indeed suggested by the data found in Asian elephants: male-mediated gene flow between groups
α
nuc and β
nuc was much lower than female-mediated gene flow.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
Joerns FickelEmail: |
2.
Marcus Clauss Reinhold R. Hofmann Jörns Fickel W. Jürgen Streich Jürgen Hummel 《Journal of morphology》2009,270(8):929-942
Browsing and grazing ruminants are thought to differ in the degree their rumen contents are stratified—which may be due to different characteristics of their respective forages, to particular adaptations of the animals, or both. However, this stratification is difficult to measure in live animals. The papillation of the rumen has been suggested as an anatomical proxy for stratification—with even papillation indicating homogenous contents, and uneven papillation (with few and small dorsal and ventral papillae, and prominent papillae in the atrium ruminis) stratified contents. Using the surface enlargement factor (SEF, indicating how basal mucosa surface is increased by papillae) of over 55 ruminant species, we demonstrate that differences between the SEFdorsal or SEFventral and the SEFatrium are significantly related to the percentage of grass in the natural diet. The more a species is adapted to grass, the more distinct this difference, with extreme grazers having unpapillated dorsal and ventral mucosa. The relative SEFdorsal as anatomical proxy for stratification, and the difference in particle and fluid retention in the rumen as physiological proxy for stratification, are highly correlated in species (n = 9) for which both kind of data are available. The results support the concept that the stratification of rumen contents varies among ruminants, with more homogenous contents in the more browsing and more stratified contents in the more grazing species. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc. 相似文献
3.
Christian Pitra Sabine Schwarz Joerns Fickel 《European Journal of Wildlife Research》2010,56(2):117-129
The raccoon dog, a medium-sized carnivore, has long been recognised as a prominent example of an invasive alien species in
Europe with a wide distribution, significant ecological impact and remarkable dynamics of spread at both national and continental
scales. We conducted a study of genetic diversity of 73 individuals collected at 20 sites across North and Central Europe
to (1) identify major phylogenetic lineages and (2) elucidate spatial patterns of population genetic structure. Reconstructed
phylogenies reveal two major clades differing on average by Tamura–Nei corrected distance of 3.4% for a 599-bp segment of
the mitochondrial control region corresponding to a coalescence time of approximately 457,800 years ago (95% CI, 223,300–773,900).
Many expectations based on introduction history, such as the presence of signatures of repeated founder effects and subsequently
rapid population expansion, were not confirmed by our demographic analyses, probably due to an insufficient amount of time
since translocations. Nevertheless, global F
ST = 13.9% and landscape approaches provided evidence for weak population genetic structure that followed a pattern of isolation
by distance. Finally, we found no congruence between previously reported morphological differentiation and the sorting of
mtDNA variation. We therefore conclude that an exceptional combination of factors including multiple translocations, secondary
contact and admixture of divergent matrilineages, as well as natural processes of colonisation associated with a wide ecological
tolerance, promoted the successful spread of the raccoon dog into Europe. 相似文献
4.
Frölich K Streich WJ Fickel J Jung S Truyen U Hentschke J Dedek J Prager D Latz N 《Journal of wildlife diseases》2005,41(1):231-235
To assess if wild carnivores in Germany play a role in the epizootiology of canine parvovirus (CPV) infection, seroprevalences against CPV in free-ranging carnivores (n=1,496) from selected urban and rural areas were compared. Antibodies against CPV were found in sera from red foxes (Vulpes vulpes; 136 of 1,442; 9%), raccoon dogs (Nyctereutes procyonides; two of 33; 6%), stone martens (Martes foina; four of 13; 31%), and pine martens (Martes martes; one of two) using the hemagglutination-inhibition test and pig erythrocytes. Evidence of CPV infection was detected in all study areas. Antibody titers varied between 10 and 320. In red foxes, the number of reactors did not differ between most urban and rural areas. However, we found significantly more reactors in the most densely populated urban area (Berlin). None of 430 tissue samples (small intestine, spleen, mesenterial lymph nodes) from any species tested for the presence of CPV nucleic acid using polymerase chain reaction yielded an amplification product. Based on our results, we believe that contact between domestic dogs and free-ranging red foxes probably plays a subordinate role in the epizootiology of CPV in Germany. 相似文献
5.
Katarina Jewgenow Frank Goeritz Katrin Neubauer Joerns Fickel Sergej V. Naidenko 《European Journal of Wildlife Research》2006,52(1):34-38
This study characterizes the reproductive activity of male European lynx kept in Central Russia. Four captive adult males
were subjected to an electroejaculation prior to (November), during (March) and after (June) the breeding season. Concentration,
motility and morphological integrity of spermatozoa as well as testis diameter and testosterone levels in serum were evaluated.
Additionally, fecal samples were collected for 2 years to determine the fecal testosterone secretion. Testis sizes and serum
testosterone concentrations were characterized by little changes with highest levels in March (2.98 mm3; 1.96 ng/ml testosterone) and lowest in June (2.34 mm3; 0.75 ng/ml testosterone). In faeces, the highest testosterone concentrations were measured in February followed by a second
increase in May. The volume of ejaculates and percentages of motile and intact spermatozoa reached the maxima in March. By
performing two-male mating experiments, we could prove multiple paternity within three litters. Paternity analysis of litter
also revealed that 26 of 31 cubs (84%) were sired from the same male, independently from being the first or second mating
partner of the respective female. This particular male showed the most developed and activated reproductive tract and also
had the best semen quality, which seems to be important for sperm competition. 相似文献
6.
Population size, one of the basic biological parameters is particularly difficult to estimate for nocturnal animals with cryptic life style and little individual distinctiveness like Eurasian otters (Lutra lutra). Because telemetric methods often fail and also expose the animals to a high risk of injuries and even mortality, we analysed DNA and hormones of spraints to obtain data on population density and structure of free-living otters in a Nature Park in north-eastern Germany. We were able to assign 53 different individual profiles from faecal samples and obtained six more profiles from animals found dead inside the park. The total population estimate (n=59) consisted of at least 32 males and 27 females; 33 animals were adult, 23 younger than 2 years (three of unknown age). Marking points were frequented by up to 12 individuals. Estimated density was one animal per 4.7 km of shoreline. The genotypically estimated total population size was more than 2.5 times as high as estimated in the past census. The method was also suited to compare otter population densities in different areas or at different times in the same area. 相似文献
7.
Convergent evolution in feeding types: salivary gland mass differences in wild ruminant species 总被引:2,自引:0,他引:2
In the ongoing debate about divergent evolutionary morphophysiological adaptations of grazing and browsing ruminants, the size of the salivary glands has received special attention. Here, we report the most comprehensive dataset on ruminant salivary glands so far, with data on the Glandula parotis (n=62 species), Gl. mandibularis (n=61), Gl. buccalis ventralis (n=44), and Gl. sublingualis (n=30). All four salivary gland complexes showed allometric scaling with body mass (BM); in all cases, the 95% confidence interval for the allometric exponent included 0.75 but did not include 1.0 (linearity); therefore, like other parameters linked to the process of food intake, salivary gland mass appears to be correlated to metabolic body weight (BM0.75), and comparisons of relative salivary gland mass between species should rather be made on the basis of BM0.75 than as a percentage of BM. In the subsequent analyses, the percentage of grass (%grass) in the natural diet was used to characterize the feeding type; the phylogenetic tree used for a controlled statistical evaluation was entirely based on mitochondrial DNA information. Regardless of phylogenetic control in the statistical treatment, there was, for all four gland complexes, a significant positive correlation of BM and gland mass, and a significant negative correlation between %grass in the natural diet and gland mass. If the Gl. parotis was analyzed either for cervid or for bovid species only, the negative correlation of gland mass and %grass was still significant in either case; an inspection of certain ruminant subfamilies, however, suggested that a convergent evolutionary adaptation can only be demonstrated if a sufficient variety of ruminant subfamilies are included in a dataset. The results support the concept that ruminant species that ingest more grass have smaller salivary glands, possibly indicating a reduced requirement for the production of salivary tannin-binding proteins. 相似文献
8.
9.
Louise Solveig Nørgaard Dorthe Marlene Götz Mikkelsen Morten Elmeros Mariann Chriél Aksel Bo Madsen Jeppe Lund Nielsen Cino Pertoldi Ettore Randi Joerns Fickel Slaska Brygida Aritz Ruiz-González 《Biological invasions》2017,19(5):1637-1652
The raccoon dog (Nyctereutes procyonoides) has a wide distribution in Europe and is a prominent example of a highly adaptable alien species. It has been recorded sporadically in Denmark since 1980 but observations since 2008 suggested that the species had established a free-ranging, self-sustaining population. To elucidate the origin and genetic patterns of Danish raccoon dogs, we studied the population genomics of 190 individuals collected in Denmark (n = 141) together with reference captive individuals from Poland (n = 21) and feral individuals from different European localities (Germany, Poland, Estonia and Finland, n = 28). We used a novel genotyping-by-sequencing approach simultaneously identifying and genotyping a large panel of single nucleotide polymorphisms (n = 4526). Overall, there was significant indication for contemporary genetic structuring of the analysed raccoon dog populations, into at least four different clusters, in spite of the existence of long distance gene flow and secondary admixture from different population sources. The Danish population was characterized by a high level of genetic admixture with neighbouring feral European ancestries and the presence of private clusters, non-retrieved in any other feral or captive populations sampled. These results suggested that the raccoon dog population in Denmark was founded by escapees from genetically unidentified Danish captive stocks, followed by a recent admixture with individuals migrating from neighbouring Germany. 相似文献
10.
J. Fickel F. Göritz B. A. Joest T. Hildebrandt R. R. Hofmann G. Breves 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1998,168(4):257-264
In ruminants, different functions have been ascribed to the different salivary glands according to the feeding type. In this
context, possible adaptations of salivary functions were investigated regarding the secretion of various proteins by different
types of salivary glands. To yield uncontaminated parotid saliva in large quantities, a non-surgical method has been developed.
Parotid gland secretions were collected via endoscopic placement of guide wires into each parotid duct, which were subsequently
used for placement of collection catheters. Salivary flow was stimulated by intra-glandular administration of the parasympathomimetic
compound pilocarpine-hydrochloride into the parotid gland. Mixed saliva (excluding parotid saliva) was collected into sterile
tubes by normal outflow during the sampling of parotid saliva. The total flow volume, flow rate and the content of proteins
as well as of several ions (Na+, K+, Ca2+, inorganic phosphate) of both types of saliva were measured in sheep, fallow deer and roe deer. Roe deer secreted the highest
amount of total salivary proteins relative to body mass [mg/kg body mass] and the highest relative volume [ml/10 min/kg body
mass], both in parotid and mixed saliva, of all ruminant species examined. Additionally, the protein profile and the tannin-binding
properties of parotid and mixed saliva in roe deer were investigated. Parotid saliva bound almost twice as much tannin as
mixed saliva, underlining the importance of yielding uncontaminated parotid saliva for tannin-binding studies.
Accepted: 6 January 1998 相似文献