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1.
Goats and some sheep synthesize a juvenile hemoglobin, Hb C (alpha 2 beta
C2), at birth and produce this hemoglobin exclusively during severe anemia.
Sheep that synthesize this juvenile hemoglobin are of the A haplotype.
Other sheep, belonging to a separate group, the B haplotype, do not
synthesize hemoglobin C and during anemia continue to produce their adult
hemoglobin. To understand the basis for this difference we have determined
the structural organization of the beta- globin locus of B-type sheep by
constructing and isolating overlapping genomic clones. These clones have
allowed us to establish the linkage map 5' epsilon I-epsilon II-psi beta
I-beta B-epsilon III-epsilon IV- psi beta II-beta F3' in this haplotype.
Thus, B sheep lack four genes, including the BC gene, and have only eight
genes, compared with the 12 found in the goat globin locus. The goat
beta-globin locus is as follows: 5' epsilon I-epsilon II-psi beta X-beta
C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-epsilon VI-psi beta
Y-beta F3'. Southern blot analysis of A-type sheep reveals that these
animals have a beta- globin locus similar to that of goat, i.e., 12 globin
genes. Thus, the beta-globin locus of B-haplotype sheep resembles that of
cows and may have retained the duplicated locus of the ancestor of cows and
sheep. Alternatively, the B-sheep locus arrangement may be the result of a
deletion of a four-gene set from the triplicated locus.
相似文献
2.
Gold salts and phenylbutazone selectively inhibit the synthesis of PGF2α and PGE2 respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE2 and PGF2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action
and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function. 相似文献
3.
Two silicone coatings have been evaluated for barnacle adhesion. One coating is an unfilled hydrosilation cured polydimethylsiloxane (PDMS) network, while the other is a room temperature vulcanized (RTV), filled, ethoxysiloxane cured PDMS elastomer, RTV11?. The adhesion strength of one species of barnacle, Balanus eburneus, to the hydrosilation coatings is in the range of 0.37–0.60 kg cm‐2 while the corresponding range for RTV11 is 0.64–0.90 kg cm‐2. The easier release of B. eburneus from the hydrosilation cured network compared to RTV11 is discussed in relationship to differences in bulk and surface properties. Preliminary results suggest bulk modulus may be the most important parameter in determining barnacle adhesion strength. In light or mechanical property analysis, a re‐evaluation of surface properties and chemical stability is presented. 相似文献
4.
Lloyd AJ William Allwood J Winder CL Dunn WB Heald JK Cristescu SM Sivakumaran A Harren FJ Mulema J Denby K Goodacre R Smith AR Mur LA 《The Plant journal : for cell and molecular biology》2011,67(5):852-868
In Arabidopsis, resistance to the necrotrophic fungus Botrytis cinerea is conferred by ethylene via poorly understood mechanisms. Metabolomic approaches compared the responses of the wild‐type, the ethylene‐insensitive mutant etr1‐1, which showed increased susceptibility, and the constitutively active ethylene mutants ctr1‐1 and eto2 both exhibited decreased susceptibility to B. cinerea. Fourier transform–infrared (FT‐IR) spectroscopy demonstrated reproducible biochemical differences between treatments and genotypes. To identify discriminatory mass‐to‐charge ratios (m/z) associated with resistance, discriminant function analysis was employed on spectra derived from direct injection electrospray ionisation‐mass spectrometry on the derived principal components of these data. Ethylene‐modulated m/z were mapped onto Arabidopsis biochemical pathways and many were associated with hydroxycinnamate and monolignol biosynthesis, both linked to cell wall modification. A high‐resolution linear triple quadrupole‐Orbitrap hybrid system confirmed the identity of key metabolites in these pathways. The contribution of these pathways to defence against B. cinerea was validated through the use of multiple Arabidopsis mutants. The FT‐IR microspectroscopy indicated that spatial accumulation of hydroxycinnamates and monolignols at the cell wall to confine disease was linked ot ethylene. These data demonstrate the power of metabolomic approaches in elucidating novel biological phenomena, especially when coupled to validation steps exploiting relevant mutant genotypes. 相似文献
5.
High-resolution temporal profiling of transcripts during Arabidopsis leaf senescence reveals a distinct chronology of processes and regulation 总被引:1,自引:0,他引:1
6.
Denby KJ Jason LJ Murray SL Last RL 《The Plant journal : for cell and molecular biology》2005,41(5):673-684
We report the characterization of an Arabidopsis thaliana mutant, ups1, isolated on the basis of reduced expression of phosphoribosylanthranilate transferase, a tryptophan biosynthetic enzyme. ups1 also exhibits defects in a wide range of defence responses. After infection with Pseudomonas syringae or Botrytis cinerea, the expression of genes regulated by both the salicylic acid and jasmonic acid/ethylene pathways is reduced in ups1 compared with wild type. Camalexin accumulation in ups1 is greatly reduced after infection with these two pathogens, as well as after amino acid starvation or oxidative stress. Reactive oxygen species (ROS)-mediated gene expression is also compromised in ups1 indicating that this mutant is defective in signalling pathways activated in response to both biotic and abiotic stress. The fact that all three major defence signalling pathways are disrupted in ups1, together with the oxidative stress phenotype, leads us to suggest that UPS1 is involved in ROS signal transduction. 相似文献
7.
PAMP recognition and the plant-pathogen arms race 总被引:1,自引:0,他引:1
Ingle RA Carstens M Denby KJ 《BioEssays : news and reviews in molecular, cellular and developmental biology》2006,28(9):880-889
Plants have evolved systems analogous to animal innate immunity that recognise pathogen-associated molecular patterns (PAMPs). PAMP detection is an important component of non-host resistance in plants and serves as an early warning system for the presence of potential pathogens. Binding of a PAMP to the appropriate pattern recognition receptor leads to downstream signalling events and, ultimately, to the induction of basal defence systems. To overcome non-host resistance, pathogens have evolved effectors that target specific regulatory components of the basal defence system. In turn, this has led to the evolution in plants of cultivar-specific resistance mediated by R proteins, which guard the targets of effectors against pathogen manipulation; the arms race continues. 相似文献
8.
Oliver Windram Priyadharshini Madhou Stuart McHattie Claire Hill Richard Hickman Emma Cooke Dafyd J. Jenkins Christopher A. Penfold Laura Baxter Emily Breeze Steven J. Kiddle Johanna Rhodes Susanna Atwell Daniel J. Kliebenstein Youn-sung Kim Oliver Stegle Karsten Borgwardt Cunjin Zhang Alex Tabrett Roxane Legaie Jonathan Moore B?rbel Finkenstadt David L. Wild Andrew Mead David Rand Jim Beynon Sascha Ott Vicky Buchanan-Wollaston Katherine J. Denby 《The Plant cell》2012,24(9):3530-3557
9.
LENE J. KJÆR ERIC M. SCHAUBER CLAYTON K. NIELSEN 《The Journal of wildlife management》2008,72(8):1819-1825
Abstract: White-tailed deer (Odocoileus virginianus) are important game mammals and potential reservoirs of diseases of domestic livestock; thus, diseases of deer are of great concern to wildlife managers. Contact, either direct or indirect, is necessary for disease transmission, but we know little about the ecological contexts that promote intrasexual contact among deer. Using pair-wise direct contacts estimated from Global Positioning System collar locations and joint utilization distributions (JUDs), we assessed habitats in which contacts occur to test whether direct contact rates among female white-tailed deer in different social groups differs among land-cover types. We also tested whether contact rates differed among seasons, lunar phases, and times of day. We obtained locations from 27 female deer for periods of 0.5–17 months during 2002–2006. We designated any simultaneous pair of locations for 2 deer <25 m apart as a direct contact. For each season, we used compositional analysis to compare land-cover types where 2 deer had contact to available land-cover weighted by their JUD. We used mixed-model logistic regression to test for effects of season, lunar phase, and time of day on contact rates. Contact rates during the gestation season were greater than expected from random use in forest and grassland cover, whereas contact rates during the fawning period were greater in agricultural fields than in other land-cover types. Contact rates were greatest during the rut and lowest in summer. Diel patterns of contact rates varied with season, and contact rates were elevated during full moon compared to other lunar periods. Both spatial and temporal analyses suggest that contact between female deer in different social groups occurs mainly during feeding, which highlights the potential impact of food distribution and habitat on contact rates among deer. By using methods to associate contacts and land-cover, we have created beneficial tools for more elaborate and detailed studies of disease transmission. Our methods can offer information necessary to develop spatially realistic models of disease transmission in deer. 相似文献
10.
Waddington SN McVey JH Bhella D Parker AL Barker K Atoda H Pink R Buckley SM Greig JA Denby L Custers J Morita T Francischetti IM Monteiro RQ Barouch DH van Rooijen N Napoli C Havenga MJ Nicklin SA Baker AH 《Cell》2008,132(3):397-409
Adenoviruses are used extensively as gene transfer agents, both experimentally and clinically. However, targeting of liver cells by adenoviruses compromises their potential efficacy. In cell culture, the adenovirus serotype 5 fiber protein engages the coxsackievirus and adenovirus receptor (CAR) to bind cells. Paradoxically, following intravascular delivery, CAR is not used for liver transduction, implicating alternate pathways. Recently, we demonstrated that coagulation factor (F)X directly binds adenovirus leading to liver infection. Here, we show that FX binds to the Ad5 hexon, not fiber, via an interaction between the FX Gla domain and hypervariable regions of the hexon surface. Binding occurs in multiple human adenovirus serotypes. Liver infection by the FX-Ad5 complex is mediated through a heparin-binding exosite in the FX serine protease domain. This study reveals an unanticipated function for hexon in mediating liver gene transfer in vivo. 相似文献