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951.
Single nucleotide polymorphisms in chicken <Emphasis Type="Italic">lmbr1</Emphasis> gene were associated with chicken growth and carcass traits 下载免费PDF全文
Huang YanQun Du XiaoHui Deng XueMei Qiu XiangPin Wang ChunKao Chen Wen Li Ning Wu ChangXin 《中国科学C辑(英文版)》2007,50(1):62-69
Lmbr1 is the key candidate gene controlling vertebrate limb development, but its effects on animal growth and carcass traits have
never been reported. In this experiment, lmbr1 was taken as the candidate gene affecting chicken growth and carcass traits. T/C and G/A mutations located in exon 16 and
one A/C mutation located in intron 5 of chicken lmbr1 were detected from Silky, White Plymouth Rock broilers and their F2 crossing chickens by PCR-SSCP and sequencing methods. The analysis of variance (ANOVA) results suggests that T/C polymorphism
of exon 16 had significant association with eviscerated yield rate (EYR), gizzard rate (GR), shank and claw rate (SCR) and
shank girth (SG); A/C polymorphism of intron 5 was significantly associated with SCR, liver rate and head-neck weight (HNW),
while both sites had no significant association with other growth and carcass traits. These results demonstrate that lmbr1 gene could be a genetic locus or linked to a major gene significantly affecting these growth and carcass traits in chicken. 相似文献
952.
953.
No information to date is available on the structure of fish major histocompatibility complex (MHC) class I and beta2-microglobulin (beta2m) proteins. In the present study, grass carp (Ctenopharyngodon idellus) MHC class I (Ctid-MHC I) and beta(2)-microglobulin (Ctid-beta2m) genes were expressed as soluble maltose binding protein (MBP)-proteins and purified in a pMAL-p2X/Escherichia coli TB1 system. The expressed proteins were purified on amylase affinity columns followed by DEAE-Sepharose. The purified products were identified by Western blotting with anti-MBP polyclonal antibodies. The MBP-Ctid-MHC I and MBP-Ctid-beta2m were cleaved separately with Factor Xa, mixed together and purified on DEAE-Sepharose. The secondary structures were analyzed by circular dichroism (CD) spectrophotometry. The three-dimensional (3D) structure of their peptide-binding domain (PBD) was modeled based sequence homology. The sequence lengths of the alpha-helix, beta-sheet, turn, and random coil in the Ctid-MHC I protein were 79aa, 75aa, 20aa, and 99aa, respectively. In the 97aa of Ctid-beta2m, the contents of the alpha-helix, beta-sheet, turn, and random coil were 0aa, 41aa, 12aa, and 44aa, respectively. The Ctid-beta2m protein displayed a typical beta-sheet. Homology modeling of the Ctid-MHC I and Ctid-beta2m proteins demonstrated similarities with the structure of human MHC class I proteins. 相似文献
954.
Accurately determining a cryoEM particle's alignment parameters is crucial to high resolution single particle 3-D reconstruction. We developed Multi-Path Simulated Annealing, a Monte-Carlo type of optimization algorithm, for globally aligning the center and orientation of a particle simultaneously. A consistency criterion was developed to ensure the alignment parameters are correct and to remove some bad particles from a large pool of images of icosahedral particles. Without using any a priori model, this procedure is able to reconstruct a structure from a random initial model. Combining the procedure above with a new empirical double threshold particle selection method, we are able to pick tens of best quality particles to reconstruct a subnanometer resolution map from scratch. Using the best 62 particles of rice dwarf virus, the reconstruction reached 9.6A resolution at which four helices of the P3A subunit of RDV are resolved. Furthermore, with the 284 best particles, the reconstruction is improved to 7.9A resolution, and 21 of 22 helices and six of seven beta sheets are resolved. 相似文献
955.
H.-C. Chang D. C. Agrawal C.-L. Kuo J.-L. Wen C.-C. Chen H.-S. Tsay 《In vitro cellular & developmental biology. Plant》2007,43(2):133-139
This study reports spore germination, early gametophyte development and change in the reproductive phase of Drynaria fortunei, a medicinal fern, in response to changes in pH and light spectra. Germination of D. fortunei spores occurred on a wide range of pH from 3.7 to 9.7. The highest germination (63.3%) occurred on ½ strength Murashige and Skoog basal medium supplemented with 2% sucrose at pH 7.7 under white light condition. Among the different light spectra tested, red, far-red, blue, and white light resulted in 71.3, 42.3, 52.7, and 71.0% spore germination, respectively. There were no morphological differences among gametophytes grown under white and blue light. Elongated or filamentous but multiseriate gametophytes developed under red light, whereas under far-red light gametophytes grew as uniseriate filaments consisting of mostly elongated cells. Different light spectra influenced development of antheridia and archegonia in the gametophytes. Gametophytes gave rise to new gametophytes and developed antheridia and archegonia after they were transferred to culture flasks. After these gametophytes were transferred to plastic tray cells with potting mix of tree fern trunk fiber mix (TFTF mix) and peatmoss the highest number of sporophytes was found. Sporophytes grown in pots developed rhizomes. 相似文献
956.
T.L. D.C. Maneval W.F. Benedict S.F. Wen P.M. Ihnat H. Engler R.J. Connor 《Cytokine & growth factor reviews》2007,18(5-6):389
Intravesical administration of interferon alpha-2b protein (IFN) has been successfully used in the treatment of patients with superficial bladder tumors. Local dosing of IFN minimizes well-known systemic side effects of the drug, but exposure to bladder tumors is limited by the duration of instillation and transient concentrations achieved in the urothelium. Intravesical delivery of the gene encoding interferon results in an alternative strategy for IFN-based therapy of the disease, enabling sustained exposure of IFN protein that results from production by tumor and non-tumor cells in the urothelium. Efficient gene delivery and expression of IFN has been achieved using a recombinant adenovirus gene delivery system (rAd-IFN) in conjunction with the novel small molecule excipient Syn3. Studies with rAd-IFN/Syn3 in animal models result in urine concentrations of IFN that persisted for weeks and correlated with potent anti-tumor effects. The objective of this review is to communicate the rationale and preclinical findings that support ongoing clinical investigation of intravesical rAd-IFN/Syn3 in superficial bladder cancer. 相似文献
957.
Homologs of eukaryotic Ras superfamily proteins in prokaryotes and their novel phylogenetic correlation with their eukaryotic analogs 总被引:1,自引:0,他引:1
Ras superfamily proteins are key regulators in a wide variety of cellular processes. Previously, they were considered to be specific to eukaryotes, and MglA, a group of obviously different prokaryotic proteins, were recognized as their only prokaryotic analogs or even ancestors. Here, taking advantage of quite a current accumulation of prokaryotic genomic databases, we have investigated the existence and taxonomic distribution of Ras superfamily protein homologs in a much wider prokaryotic range, and analyzed their phylogenetic correlation with their eukaryotic analogs. Thirteen unambiguous prokaryotic homologs, which possess the GDP/GTP-binding domain with all the five characteristic motifs of their eukaryotic analogs, were identified in 12 eubacteria and one archaebacterium, respectively. In some other archaebacteria, including four methanogenic archaebacteria and three Thermoplasmales, homologs were also found, but with the GDP/GTP-binding domains not containing all the five characteristic motifs. Many more MglA orthologs were identified than in previous studies mainly in delta-proteobacteria, and all were shown to have common unique features distinct from the Ras superfamily proteins. Our phylogenetic analysis indicated eukaryotic Rab, Ran, Ras, and Rho families have the closest phylogenetic correlation with the 13 unambiguous prokaryotic homologs, whereas the other three eukaryotic protein families (SRbeta, Sar1, and Arf) branch separately from them, but have a relatively close relationship with the methanogenic archaebacterial homologs and MglA. Although homologs were identified in a relative minority of prokaryotes with genomic databases, their presence in a relatively wide variety of lineages, their unique sequence characters distinct from those of eukaryotic analogs, and the topology of our phylogenetic tree altogether do not support their origin from eukaryotes as a result of lateral gene transfer. Therefore, we argue that Ras superfamily proteins might have already emerged at least in some prokaryotic lineages, and that the seven eukaryotic protein families of the Ras superfamily may have two independent prokaryotic origins, probably reflecting the 'fusion' evolutionary history of the eukaryotic cell. 相似文献
958.
959.
Biodegradation of phenol and 4-chlorophenol by the yeast <Emphasis Type="Italic">Candida tropicalis</Emphasis> 总被引:2,自引:0,他引:2
Biodegradation of phenol and 4-chlorophenol (4-cp) using a pure culture of Candida tropicalis was studied. The results showed that C. tropicalis could degrade 2,000 mg l−1 phenol alone and 350 mg l−1 4-cp alone within 66 and 55 h, respectively. The capacity of the strain to degrade phenol was obviously higher than that
to degrade 4-cp. In the dual-substrate system, 4-cp intensely inhibited phenol biodegradation. Phenol beyond 800 mg l−1 could not be degraded in the presence of 350 mg l−1 4-cp. Comparatively, low-concentration phenol from 100 to 600 mg l−1 supplied a sole carbon and energy source for C. tropicalis in the initial phase of biodegradation and accelerated the assimilation of 4-cp, which resulted in the fact that 4-cp biodegradation
velocity was higher than that without phenol. And the capacity of C. tropicalis to degrade 4-cp was increased up to 420 mg l−1 with the presence of 100–160 mg l−1 phenol. In addition, the intrinsic kinetics of cell growth and substrate degradation were investigated with phenol and 4-cp
as single and mixed substrates in batch cultures. The results illustrated that the models proposed adequately described the
dynamic behaviors of biodegradation by C. tropicalis. 相似文献
960.