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1.
The lipase Lip2 of the edible basidiomycete, Pleurotus sapidus, is an extracellular enzyme capable of hydrolysing xanthophyll esters with high efficiency. The gene encoding Lip2 was expressed
in Escherichia coli TOP10 using the gene III signal sequence to accumulate proteins in the periplasmatic space. The heterologous expression under
control of the araBAD promoter led to the high level production of recombinant protein, mainly as inclusion bodies, but partially
in a soluble and active form. A fusion with a C-terminal His tag was used for purification and immunochemical detection of
the target protein. This is the first example of a heterologous expression and periplasmatic accumulation of a catalytically
active lipase from a basidiomycete fungus. 相似文献
2.
Dana Bernátová 《Biologia》2008,63(2):175-176
The paper brings information on an isolated occurrence and morphological characters of Carex × involuta and C. juncella populations in the Vel’ká Fatra Mts. Their presence has been known neither from the territory of Slovakia nor from the whole
Western Carpathians till now. 相似文献
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4.
The βNACtes gene family of the Drosophila melanogaster genome provides a model for investigating the mechanisms of the molecular evolution of recently evolved genes. The βNACtes genes code for proteins that are homologous to the subunit of the nascent polypeptide-associated complex (NAC), are expressed exclusively in the testis, and are localized on the X chromosome as two-gene clusters and one separate copy. Population polymorphism of the βNACtes genes was studied using several wild-type D. melanogaster stocks, and βNACtes paralogs were compared with each other. A heterogeneous pattern was observed for βNACtes polymorphism: the 3′ genes of the two-gene clusters were low polymorphic, whereas, separate, the βNACtes1 gene was the most variable. The 5′ βNACtes copies of the two-gene tandems were practically identical, whereas the 3′ βNACtes copies were highly diverged. Hence, local gene conversion was assumed to provide for the selective homogenization of the 5′ genes. A comparison of the βNACtes paralogs showed that the majority of amino acid differences were in the N-terminal region, containing the βNAC domain. The McDonald-Kreitman test was used to analyze the divergence of βNACtes paralogs and implicated positive selection in the evolution of the βNACtes gene family. 相似文献
5.
Abdul Ghaffar Sher Afzal Khan Zahid Mukhtar Muhammad Ibrahim Rajoka Farooq Latif 《Molecular biology reports》2011,38(5):3227-3233
We studied heterologous expression of xylanase 11A gene of Chaetomium thermophilum in Pichia pastoris and characterized the thermostable nature of the purified gene product. For this purpose, the xylanase 11A gene of C. thermophilum was cloned in P. pastoris GS115 under the control of AOX1 promoter. The maximum extracellular activity of recombinant xylanase (xyn698: gene with intron) was 15.6 U ml−1 while that of recombinant without intron (xyn669) was 1.26 U ml−1 after 96 h growth. The gene product was purified apparently to homogeneity level. The optimum temperature of pure recombinant
xylanase activity was 70°C and the enzyme retained its 40.57% activity after incubation at 80°C for 10 min. It exhibited quite
lower demand of activation energy, enthalpy, Gibbs free energy, entropy, and xylan binding energy during substrate hydrolysis
than that required by that of the donor, thus indicating its thermostable nature. pH-dependent catalysis showed that it was
quite stable in a pH range of 5.5–8.5. This revealed that gene was successfully processed in P. pastoris and remained heat stable and may qualify for its potential use in paper and pulp and animal feed applications. 相似文献
6.
Matías Maggi Natalia Damiani Sergio Ruffinengo David De Jong Judith Principal Martín Eguaras 《Experimental & applied acarology》2010,50(3):269-279
We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell
width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of
worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading
female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells. 相似文献
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8.
Jörg Maletz 《Pal?ontologische Zeitschrift》2010,84(4):501-522
Graptolites from the Jaeger collection at the Museum für Naturkunde (Berlin, Germany) provide important information on structural
details of Silurian (Wenlock–Ludlow) retiolitids as well as for the biostratigraphic and biogeographic distribution of these
magnificent graptolites. Species of the genera Cometograptus, Spinograptus and Plectograptus are described from isolated glacial boulder material, collected in northern Germany and from shale specimens found in the
Lower Graptolite Shale of Thuringia. The biostratigraphic placement of material derived from glacial erratic boulders, however,
is far from being precise. The fauna associated with the neotype of Plectograptus macilentus in the ‘Unterer Graptolithenschiefer’ of Thuringia is discussed and illustrated. Cometograptus alfeisenacki from the Cyrtograptus lundgreni Biozone is recognized as a new species. The genus is discovered for the first time in North German glacial erratic boulders. 相似文献
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10.
Yanqiong Guo Chunli Feng Huanlu Song Zhaoyue Wang Qing Ren Ran Wang 《World journal of microbiology & biotechnology》2011,27(12):2807-2812
γ-Decalactone, an important flavor compound, can be produced by Yarrowia lipolytica, but the yield is poor because of lactone degradation by enzyme Aox3 (POX3 gene encoded). A yeast strain Yarrowia lipolytica TA1 of high γ-decalactone yield was constructed by integrating copper-resistance gene CRF1 from Yarrowia lipolytica into the locus of POX3 genes. After being cultured in shake-flask at 28°C for 90 h, TA1 reached a γ-decalactone yield of 0.531 g/l (highest at 63 h),
being 2.9 times higher than that of Yarrowia lipolytica As2.1045 (0.194 g/l, highest at 57 h). It was free of heterologous DNA sequences and drug-resistance genes and could be safely
used in γ-decalactone production. And this work may throw a new light on addressing the problems in commercial fragrance manufacture. 相似文献
11.
Bimal Kumar Ghimire Eun Soo Seong Jung Dae Lim Kweon Heo Myong Jo Kim Ill-Min Chung John A. Juvik Chang Yeon Yu 《Plant Cell, Tissue and Organ Culture》2008,95(3):265-274
Efficient transformation of leaf disc-derived callus of Codonopsis lanceolata was obtained using Agrobacterium tumefaciens strain LBA4404 harboring a binary vector, pYBI121, that carries the neomycin phosphotransferase (npt II) gene as a selectable marker. The green shoots recovered from agroinfected explants on selection medium (containing 0.1 mg/l
α-naphthaleneacetic acid (NAA), 1 mg/l 6-benzylaminopurine (BAP), 100 mg/l kanamycin, and 250 mg/l cefotaxime) were rooted
on Murashige and Skoog (MS) medium supplemented with 2 mg/l IBA and 10 mg/l kanamycin. To optimize the transformation conditions,
several factors were assessed, including the co-cultivation period, the duration of pre- and post-culture in darkness and
light, the kanamycin concentration, and the Agrobacterium densities. We produced transgenic Codonopsis lanceolata overexpressing γ-tocopherol methyltransferase (γ-TMT) by this protocol. Moreover, the α-tocopherol content of the plants was enhanced by the overexpression of this gene.
Bimal Kumar Ghimire and Eun Soo Seong contributed equally to this work. 相似文献
12.
Some citrus varieties express a form of apomixis termed nucellar embryony in which the adventive embryos develop from nucellus
tissue surrounding the embryo sac. This trait results in many seeds containing multiple embryos (polyembryony). Inheritance
of the frequency of polyembryony was studied in 88 progeny from a cross of Citrus maxima (monoembryonic) × Poncirus trifoliata (polyembryonic). The frequency of polyembryonic seed produced by each progeny was determined by scoring 100–500 seeds for
the number of seedlings to emerge from each seed. Two groups of eight individuals from each extreme of the population were
chosen for bulked segregant analysis with amplified fragment length polymorphism markers amplified with 256 primer combinations.
Candidate markers identified in the bulks as linked to the trait were tested on the 32 individuals used to create the bulks
and then on the remaining plants in the population. Five candidate markers tightly linked to polyembryony in P. trifoliata were identified. Specific marker alleles were present in nearly all progeny that produced polyembryonic seed, and alternate
alleles were present in nearly all progeny that produced only monoembryonic seed. The region defined by these markers very
likely contains a gene that is essential for the production of polyembryonic seeds by apomixis, but also shows segregation
distortion. The proportion of polyembryonic seeds varied widely among the hybrid progeny, probably due to other genes. Scoring
119 progeny of a P. trifoliata selfed population for the closely linked markers and the proportion of polyembryonic seeds confirmed close linkage between
these markers and polyembryony. 相似文献
13.
R. A. Matveev 《Entomological Review》2007,87(8):1074-1075
A dark form of the female horsefly Chrysops (Heterochrysops) vanderwulpi Kröber is described from Primorskii Territory of Russia and illustrated with a figure of the abdominal pattern. 相似文献
14.
Background
The presence of β-lactamases in Y. enterocolitica has been reported to vary with serovars, biovars and geographical origin of the isolates. An understanding of the β-lactamases in other related species is important for an overall perception of antibiotic resistance in yersiniae. The objective of this work was to study the characteristics of β-lactamases and their genes in strains of Y. intermedia and Y. frederiksenii, isolated from clinical and non-clinical sources in India. 相似文献15.
Yan Zhang Guiying Zhang Jiahuan Zhang Xiaoyu Wang Jinsheng Wang 《Archives of microbiology》2009,191(10):773-783
16.
Despite the widespread distribution of Astyanax bockmanni in streams from Upper Paraná River system in central, southeastern, and southern Brazil, just recently, it has been identified
as a distinct Astyanax species. Cytogenetic studies were performed in two populations of this species, revealing conservative features. A. bockmanni shows 2n = 50 chromosomes, a karyotypic formula composed of 10 M + 12SM + 12ST + 16A and multiple Ag-NORs. Eight positive signals
in subtelocentric/acrocentric chromosomes were identified by fluorescent in situ hybridization (FISH) with 18S rDNA probes.
After FISH with 5S rDNA probes, four sites were detected, comprising the interstitial region of a metacentric pair and the
terminal region on long arms of another metracentric pair. Little amounts of constitutive heterochromatin were observed, mainly
distributed at distal region in two chromosomal pairs. Additionally, heterochromatin was also located close to the centromeres
in some chromosomes. No positive signals were detected in the chromosomes of A. bockmanni by FISH with the As-51 satellite DNA probe. The studied species combines a set of characteristics previously identified in
two different Astyanax groups. The chromosomal evolution in the genus Astyanax is discussed. 相似文献
17.
Of the genes involved in galactose metabolism, GAL7, GAL10, and GAL1 are tightly linked in this order on chromosome II in Saccharomyces cerevisiae. While several species of the order Saccharomycetales have similar gene organization, Kazachstania naganishii is unique, in which GAL7 and GAL1 are close to each other whereas GAL10 is substantially apart from them on chromosome XI. In this study, we inserted the recognition sequence of I-SceI homing-endonuclease into GAL10 and also into the intervening segment of GAL7-GAL1. By cleaving chromosome DNA of the gene-manipulated strain with I-SceI, we obtained evidence that chromosome XI (610 kbp) was replaced with three fragments (305, 265, and 40 kbp). Using appropriate
probes, we further found that GAL10 was about 40 kbp apart from the GAL7-GAL1 cluster and that orientation of GAL10 was reversed comparing to the S. cerevisiae counter part. We, therefore, contend that comparison of the organization of the GAL cluster among Saccharomycetales is of importance to elucidate evolution of chromosomes and that the experimental scheme developed
in this study is useful for this line of investigation. 相似文献
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19.
Background
Thymosin α1 (Tα1), a 28-amino acid N α -acetylated peptide, has a powerful general immunostimulating activity. Although biosynthesis is an attractive means of large-scale manufacture, to date, Tα1 can only be chemosynthesized because of two obstacles to its biosynthesis: the difficulties in expressing small peptides and obtaining N α -acetylation. In this study, we describe a novel production process for N α -acetylated Tα1 in Escherichia coli. 相似文献20.
Chin-Hong Ng Soon-Leong Lee Kevin Kit-Siong Ng Norwati Muhammad Wickneswari Ratnam 《Journal of genetics》2009,88(1):25-31
The mating system and seed variation of Acacia hybrid (A. mangium × A. auriculiformis) were studied using allozymes and random amplified polymorphic DNA (RAPD) markers, respectively. Multi-locus outcrossing
rate estimations indicated that the hybrid was predominantly outcrossed (mean±s.e. t
m = 0.86±0.01). Seed variation was investigated using 35 polymorphic RAPD fragments. An analysis of molecular variance (AMOVA)
revealed the highest genetic variation among seeds within a pod (66%–70%), followed by among pods within inflorescence (29%–37%),
and the least variation among inflorescences within tree (<1%). In addition, two to four RAPD profiles could be detected among
seeds within pod. Therefore, the results suggest that a maximum of four seeds per pod could be sampled for the establishment
of a mapping population for further studies. 相似文献