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1.
Body mass (BM) and resting metabolic rates (RMR) are two inexorably linked traits strongly related to mammalian life histories. Yet, there have been no studies attempting to estimate heritable variation and covariation of BM and RMR in natural populations. We used a marker‐based approach to construct a pedigree and then the ‘animal model’ to estimate narrow sense heritability (h2) of these traits in a free‐living population of weasels Mustela nivalis—a small carnivore characterised by a wide range of BM and extremely high RMR. The most important factors affecting BM of weasels were sex and habitat type, whereas RMR was significantly affected only by seasonal variation of this trait. All environmental factors had only small effect on estimates of additive genetic variance of both BM and RMR. The amount of additive genetic variance associated with BM and estimates of heritability were high and significant in males (h2 = 0.61), but low and not significant in females (h2 = 0.32), probably due to small sample size for the latter sex. The results from the two‐trait model revealed significant phenotypic (rP = 0.62) and genetic correlation (rA = 0.89) between BM and whole body RMR. The estimate of heritability of whole body RMR (0.54) and BM corrected RMR (0.45) were lower than estimates of heritability for BM. Both phenotypic and genetic correlations between BM corrected RMR and BM had negative signals (rP = ?0.42 and rA = ?0.58). Our results indicate that total energy expenditures of individuals can quickly evolve through concerted changes in BM and RMR.  相似文献   

2.
Aims: In this study, we explored the possibility of construction of a ‘universal targeting vector’ by Red/ET recombination to inactivate L gene encoding 3‐amino‐5‐hydroxybenzoic acid (AHBA)‐oxidoreductase in AHBA biosynthetic gene cluster to facilitate the detection of ansamycins production in actinomycetes. Methods and Results: Based on the conserved regions of linked AHBA synthase (K), oxidoreductase (L) and phosphatase (M) gene clusters, degenerate primers were designed and PCR was performed to detect KLM gene clusters within 33 AHBA synthase gene‐positive actinomycetes strains. Among them, 22 KLM gene cluster‐positive strains were identified. A ‘universal targeting vector’ was further constructed using the 50‐nt homologous sequences chosen from four strains internal L gene in KLM gene clusters through Red/ET recombination. The L gene from nine of the KLM gene cluster‐positive actinomycetes strains was inactivated by insertion of a kanamycin (Km) resistance marker into its internal region from the ‘universal targeting vector’. By comparison of the metabolites produced in parent strains with those in L gene‐inactivated mutants, we demonstrated the possible ansamycins production produced by these strains. One strain (4089) was proved to be a geldanamycin producer. Three strains (3‐20, 7‐32 and 8‐32) were identified as potential triene‐ansamycins producers. Another strain (3‐27) was possible to be a streptovaricin C producer. Strains 24‐100 and 4‐124 might be served as ansamitocin‐like producers. Conclusions: The results confirmed the feasibility that a ‘universal targeting vector’ could be constructed through Red/ET recombination using the conserved regions of KLM gene clusters to detect ansamycins production in actinomycetes. Significance and Impact of the Study: The ‘universal targeting vector’ provides a rapid approach in certain degree to detect the potential ansamycin producers from the 22 KLM gene cluster‐positive actinomycetes strains.  相似文献   

3.
Fruit deformation is a phenomenon commonly observed in commercial strawberry cultivars (Fragaria×ananassa) with a negative impact on the economic benefit of crop production. To better understand this physiopathy, we evaluated fruit size and the relative amount of ‘small’ (<0.4 mm) and ‘big’ achenes (>0.6 mm) in misshapen (MF) and well‐formed (WF) fruits from ‘Camarosa’, ‘Ventana’ and ‘Medina’ strawberry cultivars growing in the field. In ‘Camarosa’, size‐dependent achenes functionality was assessed by analysing achenes germinability and differences in time to ripening between MF and WF. We found that the occurrence of fruit deformation was not only strongly dependent on the cultivar (i.e. genetic factor) but also was promoted by low temperatures (i.e. environmental factor). Regardless of the cultivar, MF showed higher percentage of ‘small’ non‐functional achenes than WF, indicating a failure in achene development, which could be related to the functional integrity of reproductive structures. To test this hypothesis, we performed an experiment by pollinating strawberry flowers with pollen developed under low and mild temperatures. Low temperatures reduced pollen viability, and flowers pollinated with low quality pollen led to a higher amount of MF. However, fruit deformation was not completely explained by differences in pollen quality, neither by differences in pistil maturity and receptivity nor ovule viability, suggesting that non‐functional achenes might result from a disruption in postfertilisation processes such as embryo abortion as a consequence of low temperatures.  相似文献   

4.
Potato plants with symptoms suggestive of potato purple top disease (PPTD) occurred in the central, western and north‐western regions of Iran. Polymerase chain reaction (PCR) and nested PCR assays were performed using phytoplasma universal primer pair P1/P7 followed by primer pairs R16F2n/R16R2 and fU5/rU3 for phytoplasma detection. Using primer pairs R16F2n/R16R2 and fU5/rU3 in nested PCR, the expected fragments were amplified from 53% of symptomatic potatoes. Restriction fragment length polymorphism (RFLP) analysis using AluI, CfoI, EcoRI, KpnI, HindIII, MseI, RsaI and TaqI restriction enzymes confirmed that different phytoplasma isolates caused PPTD in several Iranian potato‐growing areas. Sequences analysis of partial 16S rRNA gene amplified by nested PCR indicated that ‘Candidatus Phytoplasma solani’, ‘Ca. Phytoplasma astris’ and ‘Ca. Phytoplasma trifolii’ are prevalent in potato plants showing PPTD symptoms in the production areas of central, western and north‐western regions of Iran, although ‘Ca. Phytoplasma solani’ is more prevalent than other phytoplasmas. This is the first report of phytoplasmas related to ‘Ca. Phytoplasma astris’, ‘Ca. Phytoplasma solani’ and ‘Ca. Phytoplasma trifolii’ causing PPTD in Iran.  相似文献   

5.
Pear trees showing pear decline disease symptoms were observed in pear orchards in the centre and north of Iran. Detection of phytoplasmas using universal primer pair P1A/P7A followed by primer pair R16F2n/R16R2 in nested PCR confirmed association of phytoplasmas with diseased pear trees. However, PCR using group‐specific primer pairs R16(X)F1/R16(X)R1 and rp(I)F1A/rp(I)R1A showed that Iranian pear phytoplasmas are related to apple proliferation and aster yellows groups. Moreover, PCR results using primer pair ESFYf/ESFYr specific to 16SrX‐B subgroup indicated that ‘Ca. Phytoplasma prunorum’ is associated with pear decline disease in the north of Iran. RFLP analyses using HaeIII, HhaI, HinfI, HpaII and RsaI restriction enzymes confirmed the PCR results. Partial 16S rRNA, imp, rp and secY genes sequence analyses approved that ‘Ca. Phytoplasma pyri’ and ‘Ca. Phytoplasma asteris’ cause pear decline disease in the centre of Iran, whereas ‘Ca. Phytoplasma prunorum’ causes disease in the north of Iran. This is the first report of the association of ‘Ca. Phytoplasma asteris’ and ‘Ca. Phytoplasma prunorum’ with pear decline disease worldwide.  相似文献   

6.
Can a fragrance be revolutionary? In this commentary, the creation of two unusual, extravagant fine fragrances, ‘escentr?c01’ and ‘molecule01’, is described. In response to the fantasy components found in release notes of many recent perfume launches, both center around a single real fragrance raw material, the transparent woody aroma chemical ‘Iso E Super’ ( 1 + 2 ). The perfume ‘escentr?c01’ contains 65% of it, accompanied by Trisamber ( 3 ), red pepper, lime oil, incense and musks, while ‘molecule01’ consists exclusively of ‘Iso E Super’ ( 1 + 2 ). The elegant woody note lives here its own eccentric life – the revolution starts.  相似文献   

7.
1. The ability to achieve optimal camouflage varies between microhabitats in heterogeneous environments, potentially restricting individuals to a single habitat or imposing a compromise on crypsis to match several habitats. However, animals may exhibit morphological and behavioural attributes that enhance crypsis in different habitats. 2. We used an undescribed fish species, Galaxias‘nebula’, to investigate two objectives. First, we examined two potential methods of enhancing crypsis: change in colour pattern and selection of a suitable background. Second, we characterised the colour pattern of this unstudied fish and assessed its capacity for crypsis. 3. No background selection was apparent but the area of dark pigment expressed varied between backgrounds, which may negate the requirement to be choosy about habitats. The capacity to change colour and selection of a background that maximises crypsis are most likely separate, non‐mutually exclusive strategies. 4. Galaxias‘nebula’ exhibits polymorphic, non‐interchangeable colour patterns that have elements of both background pattern matching and disruptive colouration. This, coupled with habitat characteristics, suggests a combination of generalist and specialist strategies of habitat use. The fish’s camouflage strategy and air‐breathing ability may be key to survival under increasing pressure from habitat degradation and invasive predators.  相似文献   

8.
In the course of many diseases, individual non-apoptotic cells that are randomly distributed among undamaged cells in various mammalian tissues become shrunken and hyperbasophilic ("dark"). The light microscopic shrinkage is caused by a potentially reversible, dramatic compaction of all ultrastructural elements inside the affected cells, and escape of the excess water through apparently intact plasma membrane. In the case of neurons, the ultrastructural compaction rapidly involves the soma-dendrite domains in an all-or-nothing manner, and also mm-long axon segments. The present paper demonstrates that such ultrastructural compaction in neurons, which affects the whole soma-dendrite domain or long axon segments, can take place both immediately after an in vivo head injury and in rat brains perfusion-fixed for 30 min., and then chilled to just above the freezing point before the same kind of head injury was inflicted. This argues strongly against any enzyme-mediated compaction mechanism. On the analogy of gel-to-gel phase transitions in polymer chemistry, we hypothesize a pure physico-chemical compaction mechanism. Specifically, after initiation at a single site in each affected cell, the ultrastructural compaction is propelled throughout the whole cell on the domino principle by the free energy stored in the form of non-covalent interactions among the constituents of some cytoplasmic gel structure.  相似文献   

9.
Recently, peach trees showing leaf rolling, little leaf, rosetting, yellowing, bronzing of foliage and tattered and shot‐holed leaves symptoms were observed in peach growing areas in the central and north‐western regions of Iran. Polymerase chain reaction (PCR) and nested PCR using phytoplasma universal primer pairs P1/Tint, R16F2/R2, PA2F/R and NPA2F/R were employed to detect phytoplasmas. The nested PCR assays detected phytoplasma infections in 51% of symptomatic peach trees in the major peach production areas in East Azerbaijan, Isfahan, ChaharMahal‐O‐Bakhtiari and Tehran provinces. Restriction fragment length polymorphism (RFLP) analyses of 485 bp fragments amplified using primer pair NPA2F/R in nested PCR revealed that the phytoplasmas associated with infected peaches were genetically different and they were distinct from phytoplasmas that have been associated with peach and almond witches’‐broom diseases in the south of Iran. Sequence analyses of partial 16S rDNA and 16S–23S rDNA intergenic spacer regions demonstrated that ‘Candidatus Phytoplasma aurantifolia’, ‘Ca. Phytoplasma solani’ and ‘Ca. Phytoplasma trifolii’ are prevalent in peach growing areas in the central and north‐western regions of Iran.  相似文献   

10.
The prophage/phage region in the genome of ‘Candidatus Liberibacter asiaticus’, an alpha‐proteobacterium associated with citrus Huanglongbing, included many valuable loci for genetic diversity studies. Previously, a mosaic genomic region (CLIBASIA_05640 to CLIBASIA_05650) was characterized, and this revealed inter‐ and intracontinental variations of ‘Ca. L. asiaticus’. In this study, 267 ‘Ca. L. asiaticus’ isolates collected from eight provinces in China were analysed with a primer set flanking the same mosaic region plus downstream sequence. While most amplicon sizes ranged from 1400 to 2000 bp, an amplicon of 550 bp (S550) was found in 14 samples collected from south‐western China. Sequence analyses showed that S550 was the result of a 1033 bp deletion which included the previously known mosaic region. The genetic nature of the deletion event remains unknown. The regional restriction of S550 suggests that the ‘Ca. L. asiaticus’ population from south‐western China is different from those in eastern China. The small and easy‐to‐detect S550 amplicon could serve as a molecular marker for ‘Ca. L. asiaticus’ epidemiology.  相似文献   

11.
Japanese isolates of ‘Candidatus Liberibacter asiaticus’ have been shown to be clearly differentiated by simple sequence repeat (SSR) profiles at four loci. In this study, 25 SSR loci, including these four loci, were selected from the whole‐genome sequence and were used to differentiate non‐Japanese samples of ‘Ca. Liberibacter asiaticus’ (13 Indian, 3 East Timorese, 1 Papuan and 8 Floridian samples). Out of the 25 SSR loci, 13 were polymorphic. Dendrogram analysis using SSR loci showed that the clusters were mostly consistent with the geographical origins of the isolates. When single nucleotide polymorphisms (SNPs) were searched around these 25 loci, only the upstream region of locus 091 exhibited polymorphism. Phylogenetic tree analysis of the SNPs in the upstream region of locus 091 showed that Floridian samples were clustered into one group as shown by dendrogram analysis using SSR loci. The differences in nucleotide sequences were not associated with differences in the citrus hosts (lime, mandarin, lemon and sour orange) from which the isolates were originally derived.  相似文献   

12.
Activation of c‐jun N‐terminal kinase (JNK) by the mitogen‐activated protein kinase cascade has been shown to play an important role in the death of dopamine neurons of the substantia nigra, one of the principal neuronal populations affected in Parkinson’s disease. However, it has remained unknown whether the JNK2 and JNK3 isoforms, either singly or in combination, are essential for apoptotic death, and, if so, the mechanisms involved. In addition, it has been unclear whether they play a role in axonal degeneration of these neurons in disease models. To address these issues we have examined the effect of single and double jnk2 and jnk3 null mutations on apoptosis in a highly destructive neurotoxin model, that induced by intrastriatal 6‐hydroxydopamine. We find that homozygous jnk2/3 double null mutations result in a complete abrogation of apoptosis and a prolonged survival of the entire population of dopamine neurons. In spite of this complete protection at the cell soma level, there was no protection of axons. These studies provide a striking demonstration of the distinctiveness of the mechanisms that mediate cell soma and axon degeneration, and they illustrate the need to identify and target pathways of axon degeneration in the development of neuroprotective therapeutics.  相似文献   

13.
The genetic element ‘Mona’ has been shown previously to be associated with resistance to demethylation inhibitors (DMIs) in Monilinia fructicola. In this study, the promoter activity of the ‘Mona’ element was demonstrated genetically and the activity was narrowed down to a 20‐bp active region through a series of deletions. ‘Mona’ knockout transformants (ΔMona) were generated from DMI‐resistant isolate Bmpc7, and EC50 values and expression of the MfCYP51 gene were found to be reduced in transformants compared with the parental isolate. When the ‘Mona’ element was inserted into the upstream region of the MfCYP51 gene of the DMI‐sensitive isolate HG3, the EC50 values and expression of the MfCYP51 gene increased in the transformants compared with the parental sensitive isolate. These results indicate that the ‘Mona’ element determines the DMI fungicide resistance through the up‐regulation of the expression of the downstream MfCYP51 gene. No fitness penalty was observed in knockout and insertion transformants, i.e. transformants showed similar mycelial growth rate, sporulation and ability to cause lesions on fruit compared with their parental isolates, suggesting that the ‘Mona’ element does not affect basal life activities.  相似文献   

14.
Potato plants showing symptoms suggestive of potato witches’‐broom disease including witches’‐broom, little leaf, stunting, yellowing and swollen shoots formation in tubers were observed in the central Iran. For phytoplasma detection, Polymerase Chain Reaction (PCR) and nested PCR assays were performed using phytoplasma universal primer pair P1/P7, followed by primer pair R16F2n/R16R2. Random fragment length polymorphism analysis of potato phytoplasma isolates collected from different production areas using the CfoI restriction enzyme indicated that potato witches’‐broom phytoplasma isolate (PoWB) is genetically different from phytoplasmas associated with potato purple top disease in Iran. Sequence analysis of the partial 16S rRNA gene amplified by nested PCR indicated that ‘Candidatus Phytoplasma trifolii’ is associated with potato witches’‐broom disease in Iran. This is the first report of potato witches’‐broom disease in Iran.  相似文献   

15.
The feeding behaviour of crocodilians leads to the formation of particular assemblages by accumulation of carcasses on the bottom or at the edge of water points, in addition to the characteristic marks it leaves on bones, making crocodilians important taphonomic agents. We report here the case of a Pleurosternidae turtle shell, Pleurosternon bullockii (Owen 1842 ), discovered in 2014 in Angeac‐Charente in south‐western France. The shell shows a range of tooth marks left by a crocodyliform. Several elements designate Goniopholis as the most likely author of the marks and support the use of the ‘nutcracker’ technique. Some marks appear to have healed, while others suggest that this P. bullockii individual suffered from shell diseases. Many turtle remains and some ornithomimosaur dinosaur bones from Angeac‐Charente bear marks of a crocodyliform attack.  相似文献   

16.
microRNA‐9 (miR‐9) is highly expressed in the nervous system across species and plays essential roles in neurogenesis and axon growth; however, little is known about the mechanisms that link miR‐9 with dendrite growth. Using an in vivo model of Drosophila class I dendrite arborization (da) neurons, we show that miR‐9a, a Drosophila homolog of mammalian miR‐9, downregulates the cadherin protein Flamingo (Fmi) thereby attenuating dendrite development in a non‐cell autonomous manner. In miR‐9a knockout mutants, the dendrite length of a sensory neuron ddaE was significantly increased. Intriguingly, miR‐9a is specifically expressed in epithelial cells but not in neurons, thus the expression of epithelial but not neuronal Fmi is greatly elevated in miR‐9a mutants. In contrast, overexpression of Fmi in the neuron resulted in a reduction in dendrite growth, suggesting that neuronal Fmi plays a suppressive role in dendrite growth, and that increased epithelial Fmi might promote dendrite growth by competitively binding to neuronal Fmi. Fmi has been proposed as a G protein‐coupled receptor (GPCR), we find that neuronal G protein Gαq (Gq), but not Go, may function downstream of Fmi to negatively regulate dendrite growth. Taken together, our results reveal a novel function of miR‐9a in dendrite morphogenesis. Moreover, we suggest that Gq might mediate the intercellular signal of Fmi in neurons to suppress dendrite growth. Our findings provide novel insights into the complex regulatory mechanisms of microRNAs in dendrite development, and further reveal the interplay between the different components of Fmi, functioning in cadherin adhesion and GPCR signalling. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 225–237, 2016  相似文献   

17.
Apple proliferation (AP) is an important disease and is prevalent in several European countries. The causal agent of AP is ‘Candidatus Phytoplasma mali’ (‘Ca. Phytoplasma mali’). In this work, isolates of ‘Ca. Phytoplasma mali’ were detected and characterized through polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses of 16S rRNA gene and non‐ribosomal DNA fragment. The presence of three AP subtypes (AT‐1, AT‐2 and AP‐15) was identified in 31 symptomatic apple trees and two samples each constituted by a pool of five insects, collected in north‐western Italy, where AT‐1 is a dominant subtype. Subsequent nucleotide sequence analysis of the PCR‐amplified 1.8 kb (P1/P7) fragment, containing the 16S rDNA, the 16S–23S intergenic ribosomal region and the 5′‐end of the 23S rDNA, revealed the presence of at least two phytoplasmal genetic lineages within the AT‐1 subtype, designed AT‐1a and AT‐1b. Moreover, in silico single nucleotide polymorphism (SNP) analysis based on 16S rDNA sequence can differentiate AT‐1 subtype from AT‐2 and AP‐15 subtypes. Our data showed a high degree of genetic diversity among ‘Ca. Phytoplasma mali’ population in north‐western Italy and underlined the possible use of the 16S rDNA analysis for the identification and the geographical origin assignation of isolates of AP phytoplasma. Molecular markers on 16S rDNA, here identified, could be useful for studying the epidemiology of AP disease.  相似文献   

18.
Eremiadinae, one of three subfamilies of Lacertidae, are distributed throughout Asia and Africa. Previous phylogenetic studies suggested that one of the main groups of Eremiadinae (the Ethiopian clade) consist of two clades with predominately East‐African and South‐African distribution. Yet, especially the latter one, which includes the genera Pedioplanis, Meroles, Ichnotropis, Tropidosaura and Australolacerta, was not well supported in the molecular phylogenetic analysis. In this study, we analysed the phylogenetic relationships among the genera of the ‘South African clade’ to assess whether this group actually forms a highly supported clade and to address questions concerning the monophyly of the genera. We sequenced sections of the widely used mitochondrial genes coding for 16S rRNA, 12S rRNA and cytochrome b (altogether 2045 bp) as well as the nuclear genes c‐mos, RAG‐1, PRLR, KIF24, EXPH5 and RAG‐2 (altogether 4473 bp). The combined data set increased the support values for several nodes considerably. Yet, the relationships among five major lineages within the ‘South African clade’ are not clearly resolved even with this large data set. We interpret this as a ‘hard polytomy’ due to fast radiation within the South African lacertids. The combined tree based on nine marker genes provides strong support for the ‘South African Clade’ and its sister group relationship with the ‘East African Clade’. Our results confirm the genus Tropidosaura as a monophylum, while Ichnotropis is paraphyletic in our trees: Ichnotropis squamulosa appears more closely related to Meroles than to Ichnotropis capensis. Furthermore, the monophyly of Meroles is questionable as well. Based on our results, I. squamulosa should be transferred from Ichnotropis into the genus Meroles. Also, the two species of Australolacerta (A. australis and A. rupicola) are very distantly related and the genus is perhaps paraphyletic, too. Finally we propose a phylogeographical scenario in the context of palaeoclimatic data and compare it with a previously postulated hypothesis.  相似文献   

19.
The synthesis of new odorant molecules is still a challenging task for the fragrance chemist, because now as ever it is difficult to predict the odor properties of small organic molecules. Therefore, certain tools, such as, e.g., lead‐structure optimization of existing odorants, are helpful techniques. In this article, we describe the synthesis and the odor properties of a new molecule derived by the so‐called ‘seco’ lead‐structure optimization of the ambergris compound Ambroxide®. Based on these results, more representatives with similar structures have been synthesized and evaluated for their olfactory properties.  相似文献   

20.
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