排序方式: 共有60条查询结果,搜索用时 0 毫秒
21.
22.
AURÉLIE COHAS CHRISTOPHE BONENFANT† BART KEMPENAERS DOMINIQUE ALLAINɇ 《Molecular ecology》2009,18(7):1491-1503
The fitness consequences of heterozygosity and the mechanisms underpinning them are still highly controversial. Using capture–mark–recapture models, we investigated the effects of individual heterozygosity, measured at 16 microsatellite markers, on age-dependent survival and access to dominance in a socially monogamous mammalian species, the alpine marmot. We found a positive correlation between standardized multilocus heterozygosity and juvenile survival. However, there was no correlation between standardized multilocus heterozygosity and either survival of older individuals or access to dominance. The disappearance of a significant heterozygosity fitness correlation when individuals older than juveniles are considered is consistent with the prediction that differences in survival among individuals are maximal early in life. The lack of a correlation between heterozygosity and access to dominance may be a consequence of few homozygous individuals attaining the age at which they might reach dominance. Two hypotheses have been proposed to explain heterozygosity-fitness correlations: genome-wide effects reflected by all markers or local effects of specific markers linked to genes that determine fitness. In accordance with genome-wide effects of heterozygosity, we found significant correlations between heterozygosities calculated across single locus or across two sets of eight loci. Thus, the genome-wide heterozygosity effect seems to explain the observed heterozygosity-fitness correlation in the alpine marmot. 相似文献
23.
JESSICA VROONEN BART VERVUST DOMENICO FULGIONE VALERIA MASELLI RAOUL VAN DAMME 《Biological journal of the Linnean Society. Linnean Society of London》2012,107(1):182-191
Colour has many different functions in animals, such as an involvement in thermoregulation, crypsis, and social interactions. Species capable of physiological colour change may alter their coloration in response to ecological conditions. The Moorish gecko, Tarentola mauritanica, is capable of actively changing its body coloration. In the present study, we investigated colour change in this gecko as a function of background, temperature, and light. Our results demonstrate that the Moorish gecko indeed changes its dorsal colour in response to changes in environmental conditions. By contrast to several other reptilian species, this rapid colour change does not appear to be associated with thermoregulation. Background matching, however, did appear to be a prominent function, although illumination appears to be an essential trigger. Future research should concentrate on individual variation and its effectiveness with respect to antipredatory mechanisms. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??. 相似文献
24.
HANS JACQUEMYN OLIVIER HONNAY BRUNO P. A. CAMMUE REIN BRYS BART LIEVENS 《Molecular ecology》2010,19(18):4086-4095
Most orchid species rely on mycorrhizae to complete their life cycle. Despite a growing body of literature identifying orchid mycorrhizal associations, the nature and specificity of the association between orchid species and mycorrhizal fungi remains largely an open question. Nonetheless, better insights into these obligate plant–fungus associations are indispensable for understanding the biology and conservation of orchid populations. To investigate orchid mycorrhizal associations in five species of the genus Orchis (O. anthropophora, O. mascula, O. militaris, O. purpurea, and O. simia), we developed internal transcribed spacer‐based DNA arrays from extensive clone library sequence data sets, enabling rapid and simultaneous detection of a wide range of basidiomycetous mycorrhizal fungi. A low degree of specificity was observed, with two orchid species associating with nine different fungal partners. Phylogenetic analysis revealed that the majority of Orchis mycorrhizal fungi are members of the Tulasnellaceae, but in some plants, members of the Thelephoraceae, Cortinariaceae and Ceratobasidiaceae were also found. In all species except one (O. mascula), individual plants associated with more than one fungus simultaneously, and in some cases, associations with ≥3 mycorrhizal fungi at the same time were identified. Nestedness analysis showed that orchid mycorrhizal associations were significantly nested, suggesting asymmetric specialization and a dense core of interactions created by symmetric interactions between generalist species. Our results add support to the growing literature that multiple associations may be common among orchids. Low specificity or preference for a widespread fungal symbiont may partly explain the wide distribution of the investigated species. 相似文献
25.
26.
PETER H. A. GALBUSERA SARAH GILLEMOT PHILLIPPE JOUK PETER R. TESKE BART HELLEMANS FILIP A. M. J. VOLCKAERT 《Molecular ecology resources》2007,7(4):638-640
We report the isolation and characterization of 15 (12 di‐, 1 tri‐ and 2 tetranucleotide) microsatellite markers from Hippocampus capensis, the Knysna seahorse. This marker set allows the detection of a genetic bottleneck as shown in a captive population. Furthermore, we test their genotyping potential in eight other seahorse taxa. 相似文献
27.
Adaptive superparasitism in solitary parasitoids: marking of parasitized hosts in relation to the pay-off from superparasitism 总被引:4,自引:0,他引:4
Abstract.
- 1 The pay-off from an egg laid in a parasitized host is an important parameter in models on adaptive superparasitism in solitary insect parasitoids.
- 2 For Leptopilina heterotoma, a parasitoid of larval Drosophila, the pay-off from a second egg laid in a host is 0.43 offspring when the interval between the two ovipositions is less than 3h. For longer intervals, this pay-off decreases to almost zero for an interval of 24 h.
- 3 When a female encountering a parasitized host is able to estimate the interval since the first oviposition, it is expected that she will take this into account in her host selection decisions. This is, however, not in the direct interest of the female that lays the first egg, and marks the host.
- 4 We studied whether superparasitism in hosts containing a young egg is more common than in hosts containing an older egg, when searching in a patch containing once-parasitized and unparasitized hosts.
- 5 The acceptance/encounter ratio of parasitized hosts increased for intervals longer than 6h, as predicted when the interests of the marking female and the longevity of the mark are taken into account.
- 6 Superparasitism occurred more often when parasitoids had previously searched a host patch 7 days before the experiment compared to when parasitoids had searched a patch 1 day before, a phenomenon predicted by dynamic optimal diet models.
28.
Bryophyte interactions with other plants 总被引:14,自引:0,他引:14
HEIN J. DURING BART F. VAN TOOREN 《Botanical journal of the Linnean Society. Linnean Society of London》1990,104(1-3):79-98
Bryophytes live in microhabitats determined by the physical environment, usually modified by the vascular plant vegetation, and seemingly in 'ecological isolation' from other plants.
However, bryophytes are involved in a variety of competitive, parasitic, symbiotic, mutualistic and as yet unspecifiable interactions with vascular plants, algae, fungi, lichens, cyanobactcria and autotrophic and heterotrophic bacteria. In only very few cases have these interactions been analysed functionally. Yet, such information may be essential for a better understanding of (1) such aspects of bryophyte ecology as mineral nutrition, carbon economy, herbivory, and growth and development of the gametophyte, and (2) the ecological role of bryophytes in terrestrial ecosystems. 相似文献
However, bryophytes are involved in a variety of competitive, parasitic, symbiotic, mutualistic and as yet unspecifiable interactions with vascular plants, algae, fungi, lichens, cyanobactcria and autotrophic and heterotrophic bacteria. In only very few cases have these interactions been analysed functionally. Yet, such information may be essential for a better understanding of (1) such aspects of bryophyte ecology as mineral nutrition, carbon economy, herbivory, and growth and development of the gametophyte, and (2) the ecological role of bryophytes in terrestrial ecosystems. 相似文献
29.
SYNOPSIS. The synthesis of chlorophyll by chlorotic cultures of Chlamydomonas reinhardi is stimulated by a utilizable carbon source. This synthesis is almost completely inhibited by cycloheximide in concentrations as low as 0.50 μg/ml. The period of chloroplast development during which stimulation by carbon source and inhibition by cylcoheximide are most effective corresponds to a period of rapid formation of chloroplast lamellae. 相似文献
30.