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Ambrosia symbiosis is an obligate, farming-like mutualism between wood-boring beetles and fungi. It evolved at least 11 times and includes many notorious invasive pests. All ambrosia beetles studied to date cultivate ascomycotan fungi: early colonizers of recently killed trees with poor wood digestion. Beetles in the widespread genus Ambrosiodmus, however, colonize decayed wood. We characterized the mycosymbionts of three Ambrosiodmus species using quantitative culturing, high-throughput metabarcoding, and histology. We determined the fungi to be within the Polyporales, closely related to Flavodon flavus. Culture-independent sequencing of Ambrosiodmus minor mycangia revealed a single operational taxonomic unit identical to the sequences from the cultured Flavodon. Histological sectioning confirmed that Ambrosiodmus possessed preoral mycangia containing dimitic hyphae similar to cultured F. cf. flavus. The Ambrosiodmus-Flavodon symbiosis is unique in several aspects: it is the first reported association between an ambrosia beetle and a basidiomycotan fungus; the mycosymbiont grows as hyphae in the mycangia, not as budding pseudo-mycelium; and the mycosymbiont is a white-rot saprophyte rather than an early colonizer: a previously undocumented wood borer niche. Few fungi are capable of turning rotten wood into complete animal nutrition. Several thousand beetle-fungus symbioses remain unstudied and promise unknown and unexpected mycological diversity and enzymatic innovations.  相似文献   

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Entomological Review - An essay of the fauna of bark beetles (Coleoptera: Curculionidae: Scolytinae) in five federal subjects of Northwest Russia is presented. The species composition of scolytids...  相似文献   

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This paper summarizes our recent work on the histological, physiologicaland molecular aspects of limb regeneration in the fiddler crabUca pugilator and new information is presented on mitotic activityin the blastema during the first days of blastemal organization.We also report for the first time the localization of vertebrategrowth factor immunoreactivity (FGF 2 and FGF 4) in the regeneratingblastema. In the first part of this paper we review recent histologicalfindings concerning the physical events that accompany autotomyof limbs and propose a new function for the autotomy membrane—thetethering of the regenerating pedal nerve to the walls of thecoxa. In the second part of the paper we review our recent findingson the identification and characterization of the Uca ecdysteroidreceptor (UpEcR, and its potential dimer partner, the retinoid-X-receptor,UpRXR). Using Uca-specific antibody probes raised in our lab,we have been able to identify specific cells in the early blastemathat express receptor proteins. The regenerating limb of thefiddler crab is responsive to both steroids and retinoids andmRNA for steroid and retinoid receptors are expressed in theregenerating limb buds during all stages of regeneration. TheDNA and deduced amino acid sequences of the ecdysteroid receptoris very similar to the sequences of insect EcRs, while the retinoidreceptor is similar to insect protein (ultraspiracle) in theDNA-binding domain, but closer to vertebrate RXRs in the ligandbinding domain  相似文献   

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Of four media tested, a tissue culture medium supplemented with a bovine serum albumin-oleic acid complex provided the best leptospiral growth and cost efficiency.  相似文献   

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Methylobacterium extorquens strains are the best-studied methylotrophic model system, and their metabolism of single carbon compounds has been studied for over 50 years. Here we develop a new system for high-throughput batch culture of M. extorquens in microtiter plates by jointly optimizing the properties of the organism, the growth media and the culturing system. After removing cellulose synthase genes in M. extorquens strains AM1 and PA1 to prevent biofilm formation, we found that currently available lab automation equipment, integrated and managed by open source software, makes possible reliable estimates of the exponential growth rate. Using this system, we developed an optimized growth medium for M. extorquens using response surface methodologies. We found that media that used EDTA as a metal chelator inhibited growth and led to inconsistent culture conditions. In contrast, the new medium we developed with a PIPES buffer and metals chelated by citrate allowed for fast and more consistent growth rates. This new Methylobacterium PIPES (‘MP’) medium was also robust to large deviations in its component ingredients which avoided batch effects from experiments that used media prepared at different times. MP medium allows for faster and more consistent growth than other media used for M. extorquens.  相似文献   

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Zhou LW  Dai YC 《Mycologia》2012,104(4):915-924
During the examination of specimens of Theleporus and Grammothele (Polyporales, Basidiomycota) from tropical China, three new species, Theleporus membranaceus, T. minisporus and Grammothele denticulata, were identified based on both morphological and phylogenetic analyses. They are described and illustrated. T. membranaceus is characterized by its extremely thin basidiocarps (0.12 mm), small pores (7-10 per mm) and ellipsoid to broadly ellipsoid basidiospores. T. minisporus has the smallest basidiospores among the species in the genus. Grammothele denticulata is distinguished in the genus by gray pores, continuous hymenia over dissepiment edge and cylindrical basidiospores with tapering apex. Two annotated identification keys are provided for species thus far accepted in Theleporus and Grammothele. The phylogenetic relationships of Theleporus and Grammothele were inferred based on nITS sequences and are briefly discussed. The molecular evidence showed that Theleporus and Grammothele belong to the core polyporoid clade.  相似文献   

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Neurochemical Research - This study was designed to evaluate the underlying protective mechanisms of oleuropein involved in alleviating brain damage in a rat model of ischemic stroke. Male Wistar...  相似文献   

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目的:优化SD大鼠胰岛细胞的分离、纯化和培养方法与条件,为研究miR-126在Ⅱ型糖尿病中的作用机制提供活性与功能良好的胰岛细胞及miR-126表达的检测方法。方法:水合氯醛腹腔注射麻醉SD大鼠,采用8 mL胶原酶Ⅴ(含DNaseⅠ100 U)逆行注射、原位消化后Hitopaque-1077梯度离心分离纯化SD大鼠胰岛细胞,从培养后的胰岛细胞中提取总RNA,分别用加尾法和茎环法进行miR-126的反转录,实时定量PCR(qPCR)检测miR-126的表达量。结果:用该方法可从每只SD大鼠中分离、纯化得到胰岛细胞372±45个,胰岛细胞纯度90%,胰岛细胞存活率95%;用加尾法和茎环法qPCR检测miR-126的Cp值分别为34.56±2.56和32.47±2.01。结论:胶原酶Ⅴ(含DNaseⅠ100 U)逆行注射、原位消化可有效避免因消化时胶状物质的产生而导致的胰岛细胞分离失败,Hitopque-1077梯度离心分离方法具有操作简单、便捷、成功率高等特点,可得到活性与功能较好的胰岛细胞;与加尾法相比,茎环法能够更灵敏地检测胰岛细胞miR-126的表达量。  相似文献   

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The neotenic Platerodrilus net-winged beetles have strongly modified development where females do not pupate and retain larval morphology when sexually mature. As a result, dispersal propensity of females is extremely low and the lineage can be used for reconstruction of ancient dispersal and vicariance patterns and identification of centres of diversity. We identified three deep lineages in Platerodrilus occurring predominantly in (1) Borneo and the Philippines, (2) continental Asia, and (3) Sumatra, the Malay Peninsula and Java. We document limited ranges of all species of Platerodrilus and complete species level turnover between the Sunda Islands and even between individual mountain regions in Sumatra. Few dispersal events were recovered among the major geographical regions despite long evolutionary history of occurrence; all of them were dated at the early phase of Platerodrilus diversification up to the end of Miocene and no exchange of island faunas was identified during the Pliocene and Pleistocene despite the frequently exposed Sunda Shelf as sea levels fluctuated with each glacial cycle. We observed high diversity in the regions with persisting humid tropical forests during cool periods. The origins of multiple species were inferred in Sumatra soon after the island emerged and the mountain range uplifted 15 million years ago with the speciation rate lower since then. We suppose that the extremely low dispersal propensity makes Platerodrilus a valuable indicator of uninterrupted persistence of rainforests over a long time span. Additionally, if the diversity of these neotenic lineages is to be protected, a high dense system of protected areas would be necessary.  相似文献   

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