bluuebunny/crossref_metadata_2025 huggingface dataset:
HLA class I and class II frequencies in patients with sarcoidosis from Croatia: role of HLA‐B8, −DRB1*0301, and −DQB1*0201 haplotype in clinical variations of the disease
Authors: Grubić Z. , Žunec R. , Peroš‐Golubičić T. , Tekavec‐Trkanjec J. , Martinez N. , Alilović M. , Smojver‐Ježek S. , Kerhin‐Brkljačić V.
Published: July 2007

Sarcoidosis is an immune‐mediated, multiorgan, granulomatous disease triggered by a combination of environmental and genetic factors. Numerous studies have reported about an association of human leukocyte antigen (HLA) alleles with sarcoidosis, with variation of alleles in different ethnic groups. Therefore, we investigated 142 Croatian sarcoidosis patients treated at the University Hospital for Lung Diseases ‘Jordanovac’, Zagreb, Croatia. Diagnosis was based on the presence of typical clinical features, chest X‐ray findings and biopsy evidence of granuloma. Patients and control subjects (n = 190) were typed for HLA class I antigens by serology, while for HLA class II, they were tested by the polymerase chain reaction‐sequence specific primers (PCR‐SSP) method. Results indicated that HLA‐B8, −DRB1*0301, and −DQB1*0201 positive patients have a significantly higher risk of acute onset of the disease (AOD), radiological stage I erythema nodosum (EN), Löfgren’s syndrome, no‐medicament therapy, and pulmonary sarcoidosis. On the other hand, the group of non‐treated patients (corticosteroids and/or immunosuppressive) showed a significantly lower presence of HLA‐B15 antigen in comparison to controls and treated patients (P = 0.0490 and P = 0.0379, respectively) and for DRB1*04 specificity (P = 0.0078 and P = 0.0065, respectively). In the group of patients with AOD, those who were positive for DRB1*16 specificity have a statistically significant chance to develop EN, as opposed to those who are positive for DRB1*15 specificity.
Identification of two new HLA‐B alleles, HLA‐B*4069 and B*5409, in the Liaoning province of China
Authors: Li J. , Lazaro A. M. , Xiao Y. , Ng J. , Hurley C. K.
Published: July 2007

Two new human leukocyte antigen‐B alleles, B*4069 and B*5409, were identified in China.
Response of superoxide dismutase isoenzymes in tomato plants (Lycopersicon esculentum) during thermo‐acclimation of the photosynthetic apparatus
Authors: Camejo Daymi , Martí María del C. , Nicolás Emilio , Alarcón Juan J. , Jiménez Ana , Sevilla Francisca
Published: July 2007

Seedlings of Lycopersicon esculentum Mill. var. Amalia were grown in a growth chamber under a photoperiod of 16 h light at 25°C and 8 h dark at 20°C. Five different treatments were applied to 30‐day‐old plants: Control treatment (plants maintained in the normal growth conditions throughout the experimental time), heat acclimation (plants exposed to 35°C for 4 h in dark for 3 days), dark treatment (plants exposed to 25°C for 4 h in dark for 3 days), heat acclimation plus heat shock (plants that previously received the heat acclimation treatment were exposed to 45°C air temperature for 3 h in the light) and dark treatment plus heat shock (plants that previously received the dark treatment were exposed to 45°C air temperature for 3 h in the light). Only the heat acclimation treatment increased the thermotolerance of the photosynthesis apparatus when the heat shock (45°C) was imposed. In these plants, the CO2 assimilation rate was not affected by heat shock and there was a slight and non‐significant reduction in maximum carboxylation velocity of Rubisco (Vcmax) and maximum electron transport rate contributing to Rubisco regeneration (Jmax). However, the plants exposed to dark treatment plus heat shock showed a significant reduction in the CO2 assimilation rate and also in the values of Vcmax and Jmax. Chlorophyll fluorescence measurements showed increased thermotolerance in heat‐acclimated plants. The values of maximum chlorophyll fluorescence (Fm) were not modified by heat shock in these plants, while in the dark‐treated plants that received the heat shock, the Fm values were reduced, which provoked a significant reduction in the efficiency of photosystem II. A slight rise in the total superoxide dismutase (SOD) activity was found in the plants that had been subjected to both heat acclimation and heat shock, and this SOD activity was significantly higher than that found in the plants subjected to dark treatment plus heat shock. The activity of Fe‐SOD isoenzymes was most enhanced in heat‐acclimated plants but was unaltered in the plants that received the dark treatment. Total CuZn‐SOD activity was reduced in all treatments. Darkness had an inhibitory effect on the Mn‐SOD isoenzyme activity, which was compensated by the effect of a rise in air temperature to 35°C. These results show that the heat tolerance of tomatoplants may be increased by the previous imposition of a moderately high temperature and could be related with the thermal stability in the photochemical reactions and a readjustment of Vcmax and Jmax. Some isoenzymes, such as the Fe‐SODs, may also play a role in the development of heat‐shock tolerance through heat acclimation. In fact, the pattern found for these isoenzymes in heat‐acclimated Amalia plants was similar to that previously described in other heat‐tolerant tomato genotypes.
Different proportions of cadmium occur as Cd‐binding phytochelatin complexes in plants
Authors: Marentes Eduardo , Rauser Wilfried E.
Published: July 2007

The aim was to determine cadmium (Cd) speciation in various plants, between buffer‐soluble and acid‐soluble Cd, and also within the buffer‐soluble Cd. A better understanding of Cd speciation shows the relative importance of different biological mechanisms for Cd sequestration. Roots of Pistia stratiodes, Eichhornia crassipes, Agrostis gigantea, Deschampsia caespitosa and wheat Triticum turgidum var. durum were analyzed. Buffer extractions solubilized varying proportions of Cd, ranging from 12% in Eichhornia to 83% in Agrostis. The proportion increased with time of Cd exposure in Pistia. It also increased in wheat roots as the external Cd rose from 0.05 to 0.5 μM and was lowest in old leaves and highest in roots. The remaining Cd was extractable with acid. Gel filtration resolved buffer‐soluble Cd into three peaks distinct from inorganic Cd. Two complexes with phytochelatins and related polythiols were present in all cases, inorganic Cd being prominent only in Eichhornia extracts. The phytochelatin complexes accounted for 2% of the root Cd in Eichhornia to 78% in Agrostis. In wheat, phytochelatins bound 82% of the Cd in roots, 19% in young leaves and 12% in old leaves. The cysteine‐rich protein metallothionein from wheat was detected immunologically in the void volume of gel filtrations of old and young leaves, but not of roots, and was distinct from the two phytochelatin‐based complexes. Speciation of Cd in the various plants indicated that phytochelatins were not necessarily the major ligands of Cd.
The costs and benefits of resource sharing: reciprocity requires resource heterogeneity
Authors: WHITLOCK M. C. , DAVIS B. H. , YEAMAN S.
Published: July 2007

The evolution of resource sharing requires that the fitness benefits to the recipients be much higher than the costs to the giver, which requires heterogeneity among individuals in the fitness value of acquiring additional resources. We develop four models of the evolution of resource sharing by either direct or indirect reciprocity, with equal or unequal partners. Evolution of resource sharing by reciprocity requires differences between interacting individuals in the fitness value of the resource, and these differences must reverse although previous acts of giving are remembered and both participants survive. Moreover, inequality in the expected reproductive value of the interacting individuals makes reciprocity more difficult to evolve, but may still allow evolution of sharing by kin selection. These constraints suggest that resource sharing should evolve much more frequently by kin selection than by reciprocity, a prediction that is well supported by observations in the natural world.
Sexual conflict over care: antagonistic effects of clutch desertion on reproductive success of male and female penduline tits
Authors: SZENTIRMAI I. , SZÉKELY T. , KOMDEUR J.
Published: July 2007

A fundamental tenet of sexual conflict theory is that one sex may increase its reproductive success (RS) even if this harms the other sex. Several studies supported this principle by showing that males benefit from reduced paternal care whereas females suffer from it. By investigating penduline titsRemiz pendulinusin nature, we show that parental conflict may be symmetric between sexes. In this small passerine a single female (or male) cares for the offspring, whereas about 30% of clutches are deserted by both parents. Deserting parents enhance their RS by obtaining multiple mates, and they reduce the RS of their mates due to increased nest failure. Unlike most other species, however, the antagonistic interests are symmetric in penduline tits, because both sexes enhance their own RS by deserting, whilst harming the RS of their mates. We argue that the strong antagonistic interests of sexes explain the high frequency of biparental desertion.
Evolutionary acceleration in the most endangered mammal of Canada: speciation and divergence in the Vancouver Island marmot (Rodentia, Sciuridae)
Authors: CARDINI A. , THORINGTON R. W. , POLLY P. D.
Published: July 2007

The Vancouver Island marmot is the most endangered mammal of Canada. Factors which have brought this population to the verge of extinction have not yet been fully elucidated, but the effects of deforestation and habitat fragmentation on survival rates, as well as those of variation in rainfall, temperature, snowpack depth and snowmelt strongly suggest that marmots on the island are struggling to keep pace with environmental changes. Genetic analyses, however, seem to indicate that the Vancouver Island marmot may merely represent a melanistic population of its parental species on the mainland. Were it not for its black pelage colour, it is unlikely that it would have attracted much attention as a conservation priority. Our study uses three‐dimensional coordinates of cranial landmarks to further assess phenotypic differentiation of the Vancouver Island marmot. A pattern of strong interspecific divergence and low intraspecific variation was found which is consistent with aspects of drift‐driven models of speciation. However, the magnitude of shape differences relative to the putatively neutral substitutions in synonymous sites of cytochrome b is too large for being compatible with a simple neutral model. A combination of bottlenecks and selective pressures due to natural and human‐induced changes in the environment may offer a parsimonious explanation for the large phenotypic differentiation observed in the species. Our study exemplifies the usefulness of a multidisciplinary approach to the study of biological diversity for a better understanding of evolutionary models and to discover aspects of diversity that may be undetected by using only a few genetic markers to characterize population divergence and uniqueness.
Sex‐specific plasticity of growth and maturation size in a spider: implications for sexual size dimorphism
Authors: FERNÁNDEZ‐MONTRAVETA C. , MOYA‐LARAÑO J.
Published: July 2007

Sex‐specific plasticity in body size has been recently proposed to cause intraspecific patterns of variation in sexual size dimorphism (SSD). We reared juvenile male and female Mediterranean tarantulas (Lycosa tarantula) under two feeding regimes and monitored their growth until maturation. Selection gradients calculated across studies show how maturation size is under net stabilizing selection in females and under directional selection in males. This pattern was used to predict that body size should be more canalized in females than in males. As expected, feeding affected male but not female maturation size. The sex‐specific response of maturation size was related to a dramatic divergence between subadult male and female growth pathways. These results demonstrate the existence of sex‐specific canalization and resource allocation to maturation size in this species, which causes variation in SSD depending on developmental conditions consistent with the differential‐plasticity hypothesis explaining Rensch's Rule.
Adaptive divergence within and between ecotypes of the terrestrial garter snake, Thamnophis elegans, assessed with FST‐QST comparisons
Authors: MANIER M. K. , SEYLER C. M. , ARNOLD S. J.
Published: July 2007

Populations of the terrestrial garter snake (Thamnophis elegans) around Eagle Lake in California exhibit dramatic ecotypic differentiation in life history, colouration and morphology across distances as small as a few kilometres. We assayed the role of selection in ecotypic differentiation in T. elegans using FST‐QST analysis and identified selective agents using direct and indirect observations. We extended the conventional implementation of the FST‐QST approach by using three‐level analyses of genetic and phenotypic variance to assess the role of selection in differentiating populations both within and between ecotypes. These results suggest that selection has driven differentiation between as well as within ecotypes, and in the presence of moderate to high gene flow. Our findings are discussed in the context of previous correlational selection analyses which revealed stabilizing and correlational selection for some of the traits examined.
Short‐term rates of parasite evolution predict the evolution of host diversity
Authors: BUCKLING A. , HODGSON D. J.
Published: July 2007

Coevolution with parasites has been implicated as an important factor driving the evolution of host diversity. Studies to date have focussed on gross effects of parasites: how host diversity differs in the presence vs. absence of parasites. But parasite‐imposed selection is likely to show rapid variation through time. It is unclear whether short‐term fluctuations in the strength of parasite‐imposed selection tend to affect host diversity, because increases in host diversity are likely to be constrained by both the supply of genetic variation and ecological processes. We followed replicate populations of coevolving, initially isogenic, bacteria and phages through time, measuring host diversity (with respect to bacterial colony morphologies), host density and rates of parasite evolution. Both host density and time‐lagged rates of parasite evolution were good independent predictors of the magnitude of bacterial within‐ and between‐population diversities. Rapid parasite evolution and low host density decreased host within‐population diversity, but increased between‐population diversity. This study demonstrates that short‐term changes in the rate of parasite evolution can predictably drive patterns of host diversity.
Evolutionary biology of starvation resistance: what we have learned from Drosophila
Authors: RION S. , KAWECKI T. J.
Published: July 2007

Most animals face periods of food shortage and are thus expected to evolve adaptations enhancing starvation resistance (SR). Most of our knowledge of the genetic and physiological bases of those adaptations, their evolutionary correlates and trade‐offs, and patterns of within‐ and among‐population variation, comes from studies on Drosophila. In this review, we attempt to synthesize the various facets of evolutionary biology of SR emerging from those studies. Heritable variation for SR is ubiquitous in Drosophila populations, allowing for large responses to experimental selection. Individual flies can also inducibly increase their SR in response to mild nutritional stress (dietary restriction). Both the evolutionary change and the physiological plasticity involve increased accumulation of lipids, changes in carbohydrate and lipid metabolism and reduction in reproduction. They are also typically associated with greater resistance to desiccation and oxidative stress, and with prolonged development and lifespan. These responses are increasingly seen as facets of a shift of the physiology towards a ‘survival mode’, which helps the animal to survive hard times. The last decade has seen a great progress in revealing the molecular bases of induced responses to starvation, and the first genes contributing to genetic variation in SR have been identified. In contrast, little progress has been made in understanding the ecological significance of SR in Drosophila; in particular it remains unclear to what extent geographical variation in SR reflect differences in natural selection acting on this trait rather than correlated responses to selection on other traits. Drosophila offers a unique opportunity for an integrated study of the manifold aspects of adaptation to nutritional stress. Given that at least some major molecular mechanisms of response to nutritional stress seem common to animals, the insights from Drosophila are likely to apply more generally than just to dipterans or insects.
Linking Morphological and Behavioural Defences: Prey Fish Detect the Morphology of Conspecifics in the Odour Signature of their Predators
Authors: Chivers Douglas P. , Zhao Xiaoxia , Ferrari Maud C. O.
Published: July 2007

Predation is a strong selective force acting on both morphology and behaviour of prey animals. While morphological defences (e.g. crypsis, presence of armours or spines or specific body morphologies) and antipredator behaviours (e.g. change in foraging or reproductive effort, or hiding and fleeing behaviours) have been widely studied separately, few studies have considered the interplay between the two. The question raised in our study is whether antipredator behaviours of a prey fish to predator odours could be influenced by the morphology of prey conspecifics in the diet of the predator. We used goldfish (Carassius auratus) as our test species; goldfish exposed to predation risk significantly increase their body depth to length ratio, which gives them a survival advantage against gape‐limited predators. We exposed shallow‐bodied and deep‐bodied goldfish to the odour of pike (Esox lucius) fed either form of goldfish. Deep‐bodied goldfish displayed lower intensity antipredator responses than shallow‐bodied ones, consistent with the hypothesis that individuals with morphological defences should exhibit less behavioural modification than those lacking such defences. Moreover, both shallow‐ and deep‐bodied goldfish displayed their strongest antipredator responses when exposed to the odour of pike fed conspecifics of their own morphology, indicating that goldfish are able to differentiate the morphology of conspecifics through predator diet cues. For a given individual, predator threat increases as the prey become more like the individual eaten, revealing a surprising level of sophistication of chemosensory assessment by prey fish.
Ecological Risk Aversion and Foraging Behaviors of Juvenile Squirrel Monkeys (Saimiri sciureus)
Authors: Stone Anita I.
Published: July 2007

The ‘ecological risk aversion hypothesis’ [C.H. Janson and C.P. van Schaik, Juvenile Primates, Oxford Univ. Press, New York (1993), pp. 57–74] proposes that the pattern of slow growth characteristic of juvenile primates is a response to ecological risks (predation and starvation) experienced by juveniles. Juveniles are thought to avoid predation risk by positioning themselves near conspecifics, therefore experiencing high levels of feeding competition with older individuals, reduced access to resources and, consequently, high starvation risks during periods of food scarcity. The present study compared the foraging behaviors of juvenile and adult squirrel monkeys, a small neotropical primate characterized by a long juvenile period, to determine how predation and starvation risks affected juvenile behaviors. The study was conducted in Eastern Amazonia, in a seasonal environment. Due to their slow development, small body size and large group sizes, it was expected that juveniles in this species would behave in a manner consistent with the risk aversion hypothesis. However, age differences in foraging efficiency and foraging success were smaller than predicted. There was also no evidence that juveniles sacrificed access to food for predator protection. Adults did not have preferential access to fruit patches and direct competition was rare. Feeding competition for prey, the most common resource in the troop's diet, was negligible. Therefore, the slow growth and long juvenile period of squirrel monkeys do not correspond with evidence of predation or starvation risk, as predicted by the risk aversion hypothesis.
Monogynous Mating Behaviour and its Ecological Basis in the Golden Orb Spider Nephila fenestrata
Authors: Fromhage Lutz , Jacobs Kerstin , Schneider Jutta M.
Published: July 2007

Males, especially in species where they provide little or no parental investment, usually have high potential reproductive rates and are expected to maximize their fitness by mating with several females. This view is challenged, however, by species in which males provide no parental investment, but nevertheless mate with one female only. Male monogamy (monogyny), associated with an extreme investment in paternity protection, appears to be comparatively common in web‐building spiders, and has recently been subject to experimental and theoretical studies. To date, however, studies approaching this issue from an ecological perspective are rare. Theory predicts that the evolution of a monogynous mating strategy is favoured by a male‐biased sex ratio, but not necessarily by a high mortality risk for mate‐searching males. To test these predictions, we conducted a field study on the golden orb spider Nephila fenestrata, which has a mating system with potentially cannibalistic, polyandrous females, and males that are often functionally sterile after mating with one female only. Based on daily observations of marked individuals, we confirm that, consistent with laboratory findings, monogyny is common in N. fenestrata. Nevertheless, observations of male movements between females raise the possibility that a proportion of males may mate with two females. We show that the sex ratio in our study population is male‐biased, and that males incur only a relatively moderate mortality risk during mate‐search. These findings provide insights into the ecological basis for the evolutionary maintenance of monogyny.
Within and Between Species Variation in Male Mating Behaviors in the Mexican Sailfin Mollies Poecilia velifera and P. petenensis
Authors: Hankison Shala J. , Ptacek Margaret B.
Published: July 2007

Polymorphism in male morphology is often correlated with the expression of alternate behavioral tactics. This relationship between behavioral and morphological polymorphisms, however, is less well understood. We characterized male mating behaviors and morphological variation within and between Poecilia velifera and P. petenensis to understand mating signal evolution in the sailfin molly lineage. In addition, we examined whether differences between these species in the size range of mature males and the strength of allometry between dorsal fin size and body length could explain the variation observed in their expression of different mating behaviors. We determined each male's mating behavior profile by observing the behavior of a single male in the presence of a receptive female. We found that P. velifera showed evidence of an alternate male mating strategy, with small males generally performing only gonopodial thrusts (forced insemination attempts) towards receptive females, while large males performed courtship displays as well as gonopodial thrusts. Males of P. petenensis performed similar rates of courtship displays and gonopodial thrusts regardless of body length. Little variation existed among populations of P. velifera in mating behaviors, while males from different populations of P. petenensis showed population‐specific average rates of each mating behavior. Population differences in P. petenensis may be driven, in part, by its occurrence in more variable habitats than those occupied by P. velifera. Variation among individuals in the mating repertoire of P. velifera, but not P. petenensis, suggests that the greater range of variation in male size at maturity, as well as considerably stronger allometry between dorsal fin size and body length, may explain why males of P. velifera show the greatest degree of expression of alternate male mating behaviors when compared to other sailfin species. These results also suggest an important role of morphological polymorphisms in predicting the expression of alternate male mating behaviors.
Association of single nucleotide polymorphism of chicken uncoupling protein gene with muscle and fatness traits
Authors: Liu S. , Wang S.Z. , Li Z.H. , Li H.
Published: July 2007

Uncoupling proteins (UCPs) are in the mitochondrial inner membrane and belong to the transporter family. The biological function of UCPs is regulating discharge of proton gradient generated by the respiratory chain. As a result, the production of ATP is diminished, and dissipative heat is yielded. The present study was designed to investigate the association of UCP gene with chicken growth and body composition traits. The ninth generation of the broiler lines divergently selected for abdominal fat was used as a research population. Primers for UCP gene were designed from chicken genomic sequence. A single‐nucleotide polymorphism, in the exon3 (T1316C) of UCP gene was detected by the polymerase chain reaction and restriction fragment polymorphism (PCR‐RFLP) method. The UCP polymorphism was associated with muscle and fatness traits, such as pectoralis minor weight and abdominal fat weight. The results indicated that UCP gene could be a candidate locus or linked to a major gene which affects muscle and fatness traits in chicken.
Effect of dietary phosphorus and its interaction with genetic background on global gene expression in porcine muscle
Authors: Qu A. , Rothschild M.F. , Stahl C.H.
Published: July 2007

Environmental concerns and costs associated with dietary phosphorus (P) supplementation have lead to attempts to minimize the amount of P added to swine diets. In addition to its requirement for bone growth, dietary P is also necessary for muscular growth. To examine the effects of genetic background and dietary P on global gene expression in the muscle of young pigs, we utilized muscle tissue from 36 gilts sired from two different sire lines. These animals were fed either a P adequate, P deficient or P repletion diets for 14 days and showed differences in growth performance and bone integrity in response to the interaction of genetic background and dietary P. Total RNA from the loin muscle of these animals was obtained for microarray analysis. Significant differences (p < 0.01) in gene expression were seen based on the effect of sire line (339 genes), dietary P (18 genes) and the interaction between sire line and dietary P (31 genes). The microarray data were validated by semi‐quantitative real‐time PCR. These results support our hypothesis that genetic background and dietary P treatment can affect the homeorhetic control of P metabolism in pigs. Genes identified as differentially expressed in this study may be excellent candidate genes for additional work to elucidate genotype specific P requirements as well as to identify a genetic background that can maintain superior growth in a more environmentally friendly manner.
Impact of milk pricing system on the economic response to selection on milk components
Authors: Wolfová M. , Wolf J. , Přibyl J.
Published: July 2007

The impact of various milk pricing systems on the economic weights and the resulting selection responses for milk yield and fat and protein contents in Holstein and Czech Fleckvieh were investigated. The calculations were done for the situations with and without quotas on milk yield and fat content. There was a substantial influence of the milk pricing system on the selection response. The use of index weights based on a ‘wrong’ pricing system reduced the total economic selection response by up to 51% of the selection response expected for an index based on the ‘correct’ pricing system. Financial losses in the selection response were greater with quotas than without quotas. Higher losses were also calculated for Holstein compared with Czech Fleckvieh. Incorrect assumptions on the output limitation (absence or presence of milk quotas) led only to minor reductions in the total selection response (mostly <2%) if the other parameters were correct. The results indicate that customized subindices for milk production traits would increase farmers’ profit from sire selection when selling milk on the basis of different pricing systems.
Analysis of genetic diversity and conservation priorities for six north Ethiopian cattle breeds
Authors: Zerabruk M. , Bennewitz J. , Kantanen J. , Olsaker I. , Vangen O.
Published: July 2007

Genetic diversity and conservation potential of six indigenous cattle breeds of north Ethiopia was analysed based on 20 microsatellite markers using core set methods. Expected future diversity (assuming assigned extinction probabilities are valid for the next 20–50 years) were 0.988 ± 0.011 and 0.980 ± 0.010 with expected loss of diversity estimated at 0.02% and 0.74% of current level for the Maximum Variance Total (MVT) and Maximum Variance Offspring (MVO) core sets, respectively. Even though all breeds have contributed to current diversity levels, the Afar and Abergelle breeds only contributed 51% and 62% to the MVT and MVO core sets, respectively, while the Raya breed contributed only 6% and 1.5% to the MVT and MVO core set diversities, respectively. Moreover, prioritizing the six north Ethiopian cattle breeds using the conservation potential obtained from the MVT core set method seems reasonable considering the origin and migration histories of the breeds. Our results suggest that the total current genetic diversity of these breeds can be sufficiently maintained by designing a conservation strategy based on conservation potential of each breed from the MVT core set so that priority is given to lowering the extinction probabilities of breeds with high conservation potential to zero.
Testing the equivalence of different ovine PrP genotypes for estimated breeding values
Authors: Parada A. , Arana A. , Alfonso L.
Published: July 2007

In this study we applied equivalence testing methods to prove the absence of differences in genetic values of ewes with different PrP genotypes. In particular, the milk production genetic value equivalence of ARR ovine prion protein (PrP) genotypes was analysed. There is no scientific evidence implying that the performances and genetic values of different PrP genotypes will be different, but it is interesting to confirm that the performance of one genotype is indistinguishable from another before starting a genetic scrapie control programme. Genotyping was performed on 204 ewes from a Spanish population of Lacaune breed. Ewes were sampled from the lower and upper tails for the distribution of estimated breeding value (EBV) for standardized lactation. The conditional probability that the number of ARR alleles contained in the group of higher EBV was larger than that found in the group of lower EBV was found to be in the interval between the true value (1/2) and two different pre‐specified bounds (0.1 and 0.2). The results evidence the equivalence of ARR PrP genotypes for milk production EBV, and lead to the conclusion that the average genetic values for milk production of Lacaune flocks considered will not be affected by the selection of ewe carriers of resistance scrapie alleles (p < 0.05).
Study on the association of BoLA‐DRB3.2 alleles with clinical mastitis in Norwegian Red cows
Authors: Kulberg S. , Heringstad B. , Guttersrud O.A. , Olsaker I.
Published: July 2007

Genotyping of bovine leucocyte antigen DRB3.2 (BoLA‐DRB3.2) in a total of 523 Norwegian Red (NR) cows from two groups selected for high protein yield and low clinical mastitis, respectively, identified 27 previously reported BoLA‐DRB3.2 alleles across the groups. Significant differences in BoLA‐DRB3.2 allele frequencies were found between the selection groups. Alleles *13, *18, *22 and *27 had a significantly higher frequency in cows selected for low clinical mastitis, while alleles *3, *9, *11 and *26 had a higher frequency in cows selected for high protein yield. Associations between BoLA‐DRB3.2 alleles and clinical mastitis were analysed based on mastitis data from 741 072 first‐lactation NR cows, of which 452 were genotyped. Alleles *22 and *26 were found to be associated with increased clinical mastitis, while alleles *7, *11, *18 and *24 had a favourable effect on mastitis resistance. Contradictory results from different studies investigating associations between BoLA‐DRB3.2 alleles and mastitis indicate that future studies should focus on associations of mastitis with BoLA haplotypes rather than with single BoLA genes.
Evaluation of canine heat‐shock transcription factor 4 as a candidate for primary cataracts in English Cocker Spaniels and wire‐haired Kromfohrlanders
Authors: Engelhardt A. , Wöhlke A. , Distl O.
Published: July 2007

Canine heat‐shock transcription factor 4 (HSF4) was evaluated as a candidate for primary cataracts in English Cocker Spaniels (ECS) and wire‐haired Kromfohrlanders (KFL). We sequenced exon 9 and its flanking regions of the HSF4 gene in ECS and KFL but were not able to detect a previously reported insertion mutation associated with primary cataracts in Staffordshire Bull Terriers and Boston Terriers. Another single nucleotide polymorphism (LOC489766:g.3243A>G) in intron 9 was identified and included in linkage and association tests together with two flanking microsatellites. Linkage and association tests with primary cataracts in ECS and KFL were not significant. Therefore, we could not verify that the mutation in exon 9 of canine HSF4 gene is causative for primary cataracts in ECS and wire‐haired KFL.
Characterization of polymorphisms of transferrin receptor and their association with susceptibility to ETEC F4ab/ac in pigs
Authors: Wang Y. , Ren J. , Lan L. , Yan X. , Huang X. , Peng Q. , Tang H. , Zhang B. , Ji H. , Huang L.
Published: July 2007

Diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) expressing F4 (F4ab, F4ac and F4ad) fimbriae is a significant cause of mortality and morbidity in newborn and weaned pigs. The locus controlling susceptibility towards ETEC F4ab/ac has been mapped to SSC13q41, in which TFRC (transferrin receptor) was localized and considered as a positional candidate gene for ETEC F4ab/ac receptor. In this study, we determined susceptibility/resistance to ETEC F4ab/ac in a total of 755 F2 animals from a White Duroc × Erhualian intercross using a microscopic enterocyte adhesion assay. We identified two TFRC polymorphisms (SNPs 591 A>G and 632 A>G) in a single exon after comparative sequencing analysis of 2371‐bp amplicons containing the complete coding region of TFRC using RNA of eight full‐sib F2 animals with susceptible and resistant phenotypes. The intron sequences flanking the two exon polymorphisms were obtained, revealing an intron polymorphism (SNP 291 C>T). We genotyped the 19 founder animals of the White Duroc × Erhualian intercross for the identified polymorphisms, showing that only the 291 C>T polymorphism is a highly informative marker. We further genotyped all 59 F1 and 755 F2 animals for the 291 C>T polymorphism, and the association of this polymorphism with susceptibility/resistance to ETEC F4ab/ac in these F2 animals was evaluated by the transmission disequilibrium test. The result showed that the 291 C>T polymorphism is not a causal mutation, however, has a significant linkage disequilibrium with the ETEC F4ab/ac, especially F4ac receptor locus.
SNP discovery, expression and association analysis for the SDHD gene in pigs
Authors: Guimaraes S.E.F. , Rothschild M.F. , Ciobanu D. , Stahl C.H. , Lonergan S.M.
Published: July 2007

The SDHD gene was examined for single nucleotide polymorphisms (SNP) as well as for expression changes in the Longissimus dorsi muscle of commercial pigs with different potential for growth. Three SNPs, including one previously described in the coding region and two new ones in the 3′‐UTR, were found. The normalized expression of SDHD was correlated with growth, meat quality and sensory traits (p < 0.05). For the commercial pigs used in this study, as well as a Berkshire × Yorkshire resource population, the SNPs have been associated (p < 0.05) with: growth, carcass composition, meat quality and sensory traits. Despite the fact that the described SNPs were not significantly associated with the normalized expression values, the SDHD SNPs and expression were associated with growth and meat quality traits in pigs.
Monitoring of resistance for the diamondback moth to Bacillus thuringiensis Cry1Ac and Cry1Ba toxins and a Bt commercial formulation
Authors: Wang L. , Li X.‐F. , Zhang J. , Zhao J.‐Z. , Wu Q.‐J. , Xu B. , Zhang Y.‐J.
Published: July 2007

Abstract:  To monitor the resistance of field populations of the diamondback moth Plutella xylostella in China to the insecticidal protein Cry1Ac, Cry1Ba and commercial formulation Bacillus thuringiensis var. kurstaki (Btk), six representative populations of the diamondback moth were collected from Shanghai, Shandong, Hubei, Hunan, Zhejiang and Guangdong provinces of China where crucifer crop plants are intensively planted. Bioassay results showed that the populations of the diamondback moth from different locations exhibited different levels of resistance, compared with a susceptible laboratory population. The Guangdong field population was 56.15‐ and 21.90‐fold resistant to Cry1Ac and Btk, respectively. Shanghai, Hunan, Shandong and Zhejiang populations were 37.85‐, 17.24‐, 10.24‐ and 9.41‐fold resistant to Cry1Ac, respectively, but were not resistant to Btk. The Hubei population did not show resistance to Cry1Ac and Btk. Almost all tested populations were susceptible to Cry1Ba, but the Guangdong population showed some tolerance to Cry1Ba with a LC50 of 0.69 μg/ml which was 6.17‐fold higher than that of the susceptible population. The results suggested that the complex resistance patterns of field populations of P. xylostella need to be considered for expression of Bt toxin genes in genetically‐engineered crop plants and commercial formulations.
Early detection of resistance to tebufenozide in field populations of Cydia pomonella L.: methods and mechanisms
Authors: Ioriatti C. , Tasin M. , Charmillot P. J. , Reyes M. , Sauphanor B.
Published: July 2007

Abstract:  Four populations of codling moth Cydia pomonella L. were collected as overwintering larvae from apple orchards with different pesticide pressure (S. Michele, Roncafort, Revò and Vervò) in the Trento province (northern Italy). Mortality rate caused by a predetermined discriminating concentration of tebufenozide topically applied on overwintering larvae was evaluated. Neonate F1 progeny of the same populations were assayed for susceptibility to tebufenozide by feeding them on thinning apples treated with an appropriate discriminating dose of the insecticide. The activities of the main enzyme systems involved in the detoxification of insecticides were also evaluated in each population and related to their susceptibility to tebufenozide. The topical test detected a significant loss in susceptibility to tebufenozide in two populations, S. Michele and Roncafort, while all the overwintering larvae collected in the orchards of Revò and Vervò died when treated topically with the discriminating concentration. The apple‐dipping test performed on the neonate larvae showed a highly significant reduction in the susceptibility of the two populations of S. Michele and Roncafort. A less significant reduction in mortality rate was found in the Revò population; however, no statistical difference was found between the Vervò population and the susceptible reference. None of the four field populations significantly differed from the susceptible strain for Glutathione‐S‐transferase and esterase activity. A significantly higher frequency of individuals of the S. Michele and Roncafort populations exhibited a higher mixed function oxidase activity than the susceptible strain. The small resistance ratio values found for the two populations together with the low frequency of individuals exibiting enhanced enzymatic activity, reveals that the selection process was still at the early stage. Because of its efficiency in early detection of resistance to tebufenozide, topical application on diapausing larvae can thus be considered an appropriate, simple and robust tool for implementing resistance monitoring programmes for tebufenozide.
Plant Resistance to Pathogen Infection: Forms and Mechanisms of Innate and Acquired Resistance
Authors: Király L. , Barna B. , Király Z.
Published: July 2007

Different forms and mechanisms of plant resistance are compared in this review, differentiating between innate and acquired resistance. Within innate resistance, general non‐specific and specific host resistance are treated as regards the phenomena and mechanisms. Various forms of non‐specific (e.g. non‐host, basal, quantitative etc.) as well as specific resistance (extreme resistance, gene‐for‐gene resistance with the hypersensitive response, toxin resistance and gene silencing) are discussed. Within acquired resistance, the immune memory vs. stress memory of animal or plant hosts are compared. Furthermore, mechanisms of acquired resistance of plants are treated in relation to salicylate metabolism, systemic signalling, antioxidants and a recently discovered recombination signal inducing somatic mutations. It seems important for future research trends in plant pathology that several new resistance mechanisms have been discovered or at least re‐evaluated, in addition to the specific HR‐associated resistance, which has been the subject of the majority of previous research.
Performance of Fattening Pigs in a Farm Infected with Both Porcine Reproductive and Respiratory Syndrome (PRRS) Virus and Porcine Circovirus Type 2 Following Sow and Piglet Vaccination with an Attenuated PRRS Vaccine
Authors: Kritas S. K. , Alexopoulos C. , Kyriakis C. S. , Tzika E. , Kyriakis S. C.
Published: July 2007

The purpose of the study was to investigate whether, on farms with both post‐weaning multisystemic wasting syndrome (PMWS) and porcine reproductive and respiratory syndrome (PRRS), the PRRS vaccination of sows and their fattening pigs protects against these syndromes. In a farrow‐to‐finish pig farm with a history of PRRS and PMWS, 200 gilts and sows were allocated to one of two groups of equal size. The first group (C‐sow group) was used as untreated controls, while the animals of the second group (V‐sow group) were vaccinated with live Porcilis PRRS® vaccine. At the next weaning, all piglets of half the sows of the C sow group were vaccinated once at 35 days of age with the vaccine (CV group), while the offspring of the other half of the unvaccinated sows were left unvaccinated (CC group). Similarly, the offspring of half the sows of the V sow group were vaccinated (VV group), while those of the other half of the vaccinated sows were left unvaccinated (VC group). No significant differences in morbidity were observed between the groups during the nursery and finishing phases, while morbidity in the growers was significantly reduced in the CV‐ and VV‐groups (P < 0.05). Growers’ mortality was significantly reduced after piglet vaccination when compared with unvaccinated pigs of unvaccinated dams (P < 0.05). Average daily gain and feed conversion ratio were significantly improved in vaccinated piglets compared with those in the unvaccinated groups (P < 0.05).
A Scientific Background for Skeletal Muscle Conditioning in Equine Practice
Authors: Rivero J.‐L. L.
Published: July 2007

The main goal of any conditioning programme in athletic horses is to improve performance by inducing physiological changes within the animal's body. Equine skeletal muscles have a considerable potential to adapt during training and these adaptations have important physiological implications that influence stamina, strength and speed. Although there is an extensive specialized literature in this regard, scientific based muscle conditioning methods have not been introduced sufficiently in the equine sport practice. After a brief synopsis of both equine muscle exercise physiology and muscular adaptations to training, including their physiological significance, this review focuses on specific training programmes that induce muscular adaptations in athletic horses. The article addresses the following principal question: what kind of stimuli for what kind of muscular adaptations? The experimental data are discussed separately for racehorses (thoroughbreds, trotters and endurance horses) and sport horses (dressage, show jumpers and carriage). Finally, published results about the influence of relevant training parameters (such as intensity, duration and type of exercise) on muscular responses are discussed, as well as those concerning overtraining and detraining. The article closes with some concluding remarks on importance of their application in practice.
Temporal variability of disturbances: is this important for diversity and structure of marine fouling assemblages?
Authors: Sugden Heather , Panusch Rafael , Lenz Mark , Wahl Martin , Thomason Jeremy C.
Published: July 2007

Natural communities are constantly changing due to a variety of interacting external processes and the temporal occurrence and intensity of these processes can have important implications for the diversity and structure of marine sessile assemblages. In this study, we investigated the effects of temporal variation in a disturbance regime, as well as the specific timing of events within different regimes, on the composition and diversity of marine subtidal fouling assemblages. We did this in a multi‐factorial experiment using artificial settlement tiles deployed at two sites on the North East coast of England. We found that although there were significant effects of disturbances on the composition of assemblages, there were no effects of either the variation in the disturbance regime or the specific timing of events on the diversity or assemblage composition at either site. In contrast to recent implications we conclude that in marine fouling assemblages, the variability in disturbance regimes (as a driving force) is unimportant, while disturbance itself is an important force for structuring robust ecosystems.
Genetic diversity of Brassica carinata with emphasis on the interspecific crossability with B. rapa
Authors: Jiang Y. , Tian E. , Li R. , Chen L. , Meng J.
Published: July 2007

Brassica carinata (BBCC, 2n = 34) possesses many good agronomic characters and, to provide more genetic information about this species and utilize it further, 110 accessions of B. carinata were tested for genetic variation by using 233 amplified fragment length polymorphism markers, so that a dendrogram could be constructed. To combine the good traits of B. carinata and B. rapa (AA, 2n = 20) with those of B. napus (AACC, 2n = 38) which is the major rapeseed variety in China, interspecific crosses between these two species have been made which have resulted in 276 doubled hybrids (AABBCC). These hexaploids combine positive characters and can be used for crossing with B. napus. Brassica carinata as the female parents exhibited extensive differences in interspecific crossability and 20 high crossability accessions were identified. The Poisson Regression Model analysis result (P < 0.0255) indicated that such differences were due to the genotype of the accessions. Accessions with high crossability could promote gene flow within the genus Brassica.