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101.
Breeding systems in a temperate mediterranean-type climate montane sclerophyllous forest in central Chile 总被引:1,自引:0,他引:1
MARY T. KALIN ARROYO F.L.S. PAULINA USLAR 《Botanical journal of the Linnean Society. Linnean Society of London》1993,111(1):83-102
The frequency of dioecy in the predominantly biotically-pollinated native flora of a temperate montane sclerophyllous forest in central Chile, 33o S, is determined. Experimental crosses and other tests were performed on a taxonomically diverse set of annual herbs, perennial herbs and woody species to detect genetic self-incompatibility, spontaneous selfing capacity and obligate agamospermy.
The overall frequency of dioecy in the community is 9%.Dioecy is unequally represented among life-forms, increasing in frequency with greater longevity: 0% in annual herbs; 2% in perennial herbs; 17% in shrubs; 57% in trees. Thirty-eight percent of 37 hermaphrodite species proved to be genetically self-incompatible. Self-incompatibility, like dioecy, increases in frequency with longevity: 0% in annual herbs; 50% in perennial herbs; 80% in shrubs. The self-compatible species showed a wide range of breeding habits from facultative outcrossing to strong autogamy. However, in most self-compatible species hand self-pollination increased fruit and seed set over spontaneous selfing. Obligate agamospermy was not detected among hermaphrodite specieS. Absolute and relative fecundity were strongly correlated with the degree of compatibility. However, reduced fecundity in obligate outbreeding species could not be unequivocally attributed to pollinator limitation.
For equivalent life-forms, the montane sclerophyllous forest exhibits proportionately more obligate outbreeding species than some tropical forests and other temperate communities. The strong tendency for obligate outcrossing in the Chilean community is seen as a result of interplay between life-history constraints and the intense abiotic and biotic pressures that are characteristic of the mediterranean-type climate community. 相似文献
The overall frequency of dioecy in the community is 9%.Dioecy is unequally represented among life-forms, increasing in frequency with greater longevity: 0% in annual herbs; 2% in perennial herbs; 17% in shrubs; 57% in trees. Thirty-eight percent of 37 hermaphrodite species proved to be genetically self-incompatible. Self-incompatibility, like dioecy, increases in frequency with longevity: 0% in annual herbs; 50% in perennial herbs; 80% in shrubs. The self-compatible species showed a wide range of breeding habits from facultative outcrossing to strong autogamy. However, in most self-compatible species hand self-pollination increased fruit and seed set over spontaneous selfing. Obligate agamospermy was not detected among hermaphrodite specieS. Absolute and relative fecundity were strongly correlated with the degree of compatibility. However, reduced fecundity in obligate outbreeding species could not be unequivocally attributed to pollinator limitation.
For equivalent life-forms, the montane sclerophyllous forest exhibits proportionately more obligate outbreeding species than some tropical forests and other temperate communities. The strong tendency for obligate outcrossing in the Chilean community is seen as a result of interplay between life-history constraints and the intense abiotic and biotic pressures that are characteristic of the mediterranean-type climate community. 相似文献
102.
Benjamin R Harrison Jessica M Hoffman Ariana Samuelson Daniel Raftery Daniel E L Promislow 《Molecular biology and evolution》2022,39(1)
Comparative phylogenetic studies offer a powerful approach to study the evolution of complex traits. Although much effort has been devoted to the evolution of the genome and to organismal phenotypes, until now relatively little work has been done on the evolution of the metabolome, despite the fact that it is composed of the basic structural and functional building blocks of all organisms. Here we explore variation in metabolite levels across 50 My of evolution in the genus Drosophila, employing a common garden design to measure the metabolome within and among 11 species of Drosophila. We find that both sex and age have dramatic and evolutionarily conserved effects on the metabolome. We also find substantial evidence that many metabolite pairs covary after phylogenetic correction, and that such metabolome coevolution is modular. Some of these modules are enriched for specific biochemical pathways and show different evolutionary trajectories, with some showing signs of stabilizing selection. Both observations suggest that functional relationships may ultimately cause such modularity. These coevolutionary patterns also differ between sexes and are affected by age. We explore the relevance of modular evolution to fitness by associating modules with lifespan variation measured in the same common garden. We find several modules associated with lifespan, particularly in the metabolome of older flies. Oxaloacetate levels in older females appear to coevolve with lifespan, and a lifespan-associated module in older females suggests that metabolic associations could underlie 50 My of lifespan evolution. 相似文献
103.
Ariana Vieira Alves Eliana Janet Sanjinez Argando?a Adelita Maria Linzmeier Claudia Andrea Lima Cardoso Maria Lígia Rodrigues Macedo 《PloS one》2016,11(3)
Insects have played an important role as human food throughout history,
especially in Africa, Asia and Latin America. A good example of edible insects
is the mealworm, Tenebrio molitor Linnaeus, 1758 (Coleoptera,
Tenebrionidae), which are eaten in Africa, Asia, the Americas and Australia.
This species is easily bred in captivity, requiring simple management. The
bocaiuva (Acrocomia aculeata (Jacq.) Lodd) is an abundant palm
tree found in the Brazilian Cerrado, providing fruits with high nutritional
value. The aim of this work was to determine the chemical composition of
T. molitor grown in different artificial
diets with bocaiuva pulp flour. The nutritional composition, fatty acid
composition, antioxidant activity, trypsin activity and anti-nutritional factors
of larvae were analyzed. The results showed that mealworms grown on artificial
diet with bocaiuva are a good source of protein (44.83%) and lipid (40.45%),
with significant levels of unsaturated fatty acids (65.99%), antioxidant
activity (4.5 μM Trolox/g of oil extracted from larvae) and absence of
anti-nutritional factors. This study indicates a new source of biomass for
growing mealworms and shows that it is possible to breed mealworms in artificial
diet with bocaiuva flour without compromising the nutritional quality of the
larvae. 相似文献
104.
The diversity in the expression profile of caveolin II transcripts,considering its new transcript in breast cancer 下载免费PDF全文
105.
106.
A Gallego VL Gemini AA Rossen SL Rossi V Trípodi D Corach E Planes SE Korol 《World journal of microbiology & biotechnology》2012,28(3):1245-1252
An indigenous strain of Pseudomonas putida capable of degrading 3-chlorobenzoic acid as the sole carbon source was isolated from the Riachuelo, a polluted river in
Buenos Aires. Aerobic biodegradation assays were performed using a 2-l microfermentor. Biodegradation was evaluated by spectrophotometry,
chloride release, gas chromatography and microbial growth. Detoxification was evaluated by using Vibrio fischeri, Pseudokirchneriella
subcapitata and Lactuca sativa as test organisms. The indigenous bacterial strain degrades 100 mg l−1 3-chlorobenzoic acid in 14 h with a removal efficiency of 92.0 and 86.1% expressed as compound and chemical oxygen demand
removal, respectively. The strain was capable of degrading up to 1,000 mg of the compound l−1. Toxicity was not detected at the end of the biodegradation process. Besides initial concentration, the effect of different
factors, such as initial pH, initial inoculum, adaptation to the compound and presence of other substrates and toxic related
compounds, was studied. 相似文献
107.
Brown TA Tkachuk AN Shtengel G Kopek BG Bogenhagen DF Hess HF Clayton DA 《Molecular and cellular biology》2011,31(24):4994-5010
A fundamental objective in molecular biology is to understand how DNA is organized in concert with various proteins, RNA, and biological membranes. Mitochondria maintain and express their own DNA (mtDNA), which is arranged within structures called nucleoids. Their functions, dimensions, composition, and precise locations relative to other mitochondrial structures are poorly defined. Superresolution fluorescence microscopy techniques that exceed the previous limits of imaging within the small and highly compartmentalized mitochondria have been recently developed. We have improved and employed both two- and three-dimensional applications of photoactivated localization microscopy (PALM and iPALM, respectively) to visualize the core dimensions and relative locations of mitochondrial nucleoids at an unprecedented resolution. PALM reveals that nucleoids differ greatly in size and shape. Three-dimensional volumetric analysis indicates that, on average, the mtDNA within ellipsoidal nucleoids is extraordinarily condensed. Two-color PALM shows that the freely diffusible mitochondrial matrix protein is largely excluded from the nucleoid. In contrast, nucleoids are closely associated with the inner membrane and often appear to be wrapped around cristae or crista-like inner membrane invaginations. Determinations revealing high packing density, separation from the matrix, and tight association with the inner membrane underscore the role of mechanisms that regulate access to mtDNA and that remain largely unknown. 相似文献
108.
In 2002, International Agency for Research on Cancer launched a multicentric case-control study of head and neck cancer in 15 centres in 11 European countries, Croatia included. The Alcohol-related Cancers and Genetic Susceptibility in Europe (ARCAGE) study database with approximately 2500 case-control pairs is currently the largest head and neck cancer patients database in Europe. The aim of the present study was to estimate the risk of smoking and alcohol consumption in head and neck cancer patients from Zagreb region recruited in scope of the ARCAGE study. The cases (45 males, 9 females) and the controls (37 males, 9 females) were recruited from University Hospital Dubrava and Merkur University Hospital. A blood sample and a lifestyle questionnaire were collected from all study subjects. Data were analysed by logistic regression analysis. The distribution of cases was: 43 oral, 9 pharyngeal and 2 laryngeal cancer cases. Ever-smokers had a 4-fold higher cancer risk (adjusted OR 4.3 (CI 1.20-15.4)) compared to never-smokers. The adjusted odds ratio for alcohol consumption more than once a week was 4.1 (CI 1.5-11.2). The results are in keeping with previously published data from other countries. 相似文献
109.
There is growing interest in the biology of dysbindin and its genetic locus (DTNBP1) due to genetic variants associated with an increased risk of schizophrenia. Reduced levels of dysbindin mRNA and protein
in the hippocampal formation of schizophrenia patients further support involvement of this locus in disease risk. Here, we
discuss phylogenetically conserved dysbindin molecular interactions that define its contribution to the assembly of the biogenesis
of lysosome-related organelles complex-1 (BLOC-1). We explore fundamental cellular processes where dysbindin and the dysbindin-containing
BLOC-1 complex are implicated. We propose that cellular, tissue, and system neurological phenotypes from dysbindin deficiencies
in model genetic organisms, and likely individuals affected with schizophrenia, emerge from abnormalities in few core cellular
mechanisms controlled by BLOC-1-dysbindin-containing complex rather than from defects in dysbindin itself. 相似文献
110.
Global biodiversity loss has prompted research on the relationship between species diversity and ecosystem functioning. Few studies have examined how plant diversity impacts belowground processes; even fewer have examined how varying resource levels can influence the effect of plant diversity on microbial activity. In a field experiment in a restored wetland, we examined the role of plant trait diversity (or functional diversity, (FD)) and its interactions with natural levels of variability of soil properties, on a microbial process, denitrification potential (DNP). We demonstrated that FD significantly affected microbial DNP through its interactions with soil conditions; increasing FD led to increased DNP but mainly at higher levels of soil resources. Our results suggest that the effect of species diversity on ecosystem functioning may depend on environmental factors such as resource availability. Future biodiversity experiments should examine how natural levels of environmental variability impact the importance of biodiversity to ecosystem functioning. 相似文献