bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limb proportions and adaptations in caviomorph rodents (Rodentia: Caviomorpha)
Authors: Elissamburu A. , Vizcaíno S. F. 
Published: January 2004

AbstractCaviomorph rodents (Rodentia: Caviomorpha) are an anatomically variable group with diverse ecological and morphological types, including cursorial, digging, fossorial and swimming forms. Their appendicular skeleton is rather generalized and extreme modifications or reductions in the long bones of limbs are not present. It is of special interest to evaluate functional adaptive variations of the appendicular skeleton within this group. Although much work has been devoted to study structure, function, and kinematics of legs in mammals, most studies do not consider particular functions and behaviour within different mammalian lineages. Morphometric and biomechanical studies were performed to test the relationship between adaptation and morphology of the bones of the proximal and middle limb segments in terrestrial caviomorph rodents. Fifty‐four specimens belonging to 10 species with different limb adaptations and representing a wide range of body sizes were measured. Diameters and functional lengths of long bones were taken and nine functional indices were built. Humerus (HRI) and ulna (URI) robustness, humerus deltoid (SMI) and epicondyle (EI) development, olecranon proportion (IFA), femur (FRI) and tibia (TRI) robustness, and gluteal muscle insertion at femur (GI), were calculated. Only TRI and, to a lesser degree, SMI and EI, were significantly related to body mass. A functional sequence (cursorial–generalized–occasional digging–diggers) which seems to reflect an increase in force and muscular development in middle segments of the fore limb is recognized. The hind limb shows a decrease in the speed efficiency of the femur and an increase in limb robustness in the transition from cursorial to digging forms. Although overlapping of speed and force functions in the limbs is evident, functional differentiation for speed in the proximal, and force in the middle segments can be inferred.
Sex‐related growth patterns in a caecilian amphibian (genus Ichthyophis): evidence from laboratory data
Authors: Kupfer Alexander , Kramer Armin , Himstedt Werner 
Published: January 2004

AbstractPost‐metamorphic growth patterns were analysed in the tropical caecilian amphibian Ichthyophis cf. kohtaoensis (Amphibia: Gymnophiona) experimentally in captivity over 6 years. Two questions were addressed. (1) Does this Ichthyophis display sexual dimorphism for size? (2) Do ichthyophiid caecilians express an indeterminate growth pattern? Total length did not differ between sexes in the first, second or third year after metamorphosis. In the fourth, fifth and sixth years, females were significantly larger than males. The index of sexual size dimorphism increased from zero in the first year after metamorphosis to 0.104 in the sixth year. Relative growth rates of total length were different for each sex. In the first two growth seasons males grew at higher rates, while from the third growth season females grew faster than males. In general, growth rates increased from the first to the second year after metamorphosis and decreased dramatically after both sexes became mature. As all Ichthyophis in this study grew constantly throughout the first 6 years after metamorphosis, indeterminate growth probably occurs in caecilians as reported for frogs and salamanders. Additionally, growth curves for both sexes of Ichthyophis cf. kohtaoensis were estimated based on the von Bertalanffy model.
Lek‐like mating in white‐nosed coatis (Nasua narica): socio‐ecological correlates of intraspecific variability in mating systems
Authors: Booth‐Binczik S. D. , Binczik G. A. , Labisky R. F. 
Published: January 2004

AbstractThe mating system displayed by a species or population is a complex result of interactions among many factors, including social organization and resource distribution. Lekking is rare among mammals, and despite decades of research and theoretical debate, there is still little agreement concerning the socio‐ecological conditions that give rise to this mating system. This study documents a lek‐like mating system in a population of white‐nosed coatis Nasua narica: the first such system observed in a carnivore species. Male coatis in Tikal National Park, Guatemala, aggregated around mobile bands of females during the mating season. The males displayed from the forest canopy above the bands, and females ascended to a male's perch when they were ready to mate. Males did not provide resources or parental care. Thus, the mating system, which differed from classic lekking only in the lack of an arena, can be best described as mobile lekking. Male coatis apparently resort to self‐advertisement when the large size and large home ranges of female groups make defence of females or resources impractical.
Seasonal movement patterns of woodland caribou (Rangifer tarandus caribou)
Authors: Ferguson S. H. , Elkie P. C. 
Published: January 2004

AbstractFor species conservation, defining seasons according to an animal's perception and consideration of seasonal differences in its use of space is required. First, a statistical approach was used to determine seasons based on rates of movement of radio‐collared caribou Rangifer tarandus caribou. Using polynomial regression, five seasons were delineated by inflection points that demarcate changes in rates of movement. Male and female caribou did not differ in timing and number of seasons. Second, the seasons so defined were used to describe the use of space in 33 caribou in north‐western Ontario, Canada. Greatest rates of movement occurred during spring and early winter migration when caribou had both the largest range size and largest distance between seasonal ranges. The general direction of movement was west in spring and east early in winter, although variation occurred among caribou and years. A drop in rate of movement lasting about 3 days may indicate calving. Caribou were most dispersed and occupied the smallest seasonal range during the calving season. The animals showed strong fidelity to calving areas in contrast to the highly variable year‐to‐year location of winter ranges. Understanding the seasons of animal movement patterns, and applying this understanding when developing plans for forest management, may help reduce adverse effects of forest harvesting on highly mobile animals such as woodland caribou.
Predicting carnivoran body mass from a weight‐bearing joint
Authors: Andersson Ki 
Published: January 2004

AbstractPredictors used to calculate the body mass of extinct carnivorans often scale differently between different taxa, thus yielding body mass estimates that diverge considerably depending on which predictive equation is used. This requires the investigator to choose the ones most suitable, a procedure that is best avoided if possible. The carnivoran elbow joint is here explored with the aim of producing a single general body mass predictor that can be used over a broad range of terrestrial and arboreal carnivorans. The circumference of the distal humerus trochlea is found to be highly correlated with body mass, and trochlea circumference seems to scale similarly throughout the order Carnivora. This scaling is not as theoretically predicted by elastic similarity and is slightly higher than that predicted by geometric similarity, indicating a slight positive allometry for the latter. Some degree of differential scaling between carnivoran families and between animals of large and small size cannot be ruled out, but this result is inconclusive. A predictive model that allows mass estimations for a broad range of carnivorans is presented (a=0.601; b=2.552; r2=0.952, see=0.136, P<0001, n=92). Body mass for eight extinct carnivoran species are calculated and these generally conform to earlier mass predictions.
Apoptosis does not play an important role in the resistance of ‘immune’Penaeus japonicus against white spot syndrome virus
Authors: Wu J L , Muroga K 
Published: January 2004

AbstractWe previously demonstrated that kuruma shrimp, Penaeus japonicus, exposed to white spot syndrome virus (WSSV) became resistant (‘immune’ shrimp) to subsequent challenge with the virus. The present study investigated the role of apoptosis in the ‘immune’ shrimp during a secondary challenge with WSSV. When naive kuruma shrimp were intramuscularly injected with WSSV at a high or low dose, apoptosis was often detected by TUNEL assay in the lymphoid organ (LO), mainly in the early stage of the infection. A significantly higher incidence of apoptosis was observed in the LO of the shrimp injected with the high dose of WSSV (cumulative mortality: 100%) than in the shrimp injected with the low dose (cumulative mortality: 0%). When ‘immune’ and naive shrimp were injected with an equal dose of WSSV, the incidence of apoptosis was significantly lower in the ‘immune’ shrimp than in the naive shrimp. This difference is assumed to result from a substantial reduction of the virus by humoral neutralizing factor in the ‘immune’ shrimp. These results suggest that apoptosis is not a principal protective factor in ‘immune’ shrimp.
Localization of carbohydrate terminals on Tetracapsuloides bryosalmonae using lectin histochemistry and immunogold electron microscopy
Authors: Morris D J , Adams A 
Published: January 2004

Abstract Tetracapsuloides bryosalmonae is the myxozoan parasite that causes the commercially important proliferative kidney disease (PKD) in salmonid aquaculture. Previous studies on the binding of lectins to T. bryosalmonae identified Griffonia simplificola agglutinin I (GS I) as useful for parasite identification. This lectin was also implicated as recognizing antigenic structures on the parasite. Here, we examine the histochemical staining and ultrastructural localization of a panel of 21 lectins on the extrasporogonic stage of T. bryosalmonae. The histochemical staining studies indicated that the majority of lectins bound to the renal stages of T. bryosalmonae, however not all of these lectins could be successfully localized using immunogold electron microscopy. Of the lectins that were localized many, including GS I, bound to membranes associated with the lysosomal pathway within the extrasporogonic primary cell of the parasite, indicating that these organelles are rich in glycoconjugates. The histochemical staining of Erythrina cristagalli ECL was unique and highlighted a different distribution of glycoconjugates in the periphery of some extrasporogonic parasites within the renal sinuses when compared with stages in the interstitium, suggesting the presence of distinct blood forms of T. bryosalmonae.
The effect of in vivo growth on the cellular and extracellular components of the marine bacterial pathogen Photobacterium damsela subsp. piscicida
Authors: Bakopoulos V , Hanif A , Poulos K , Galeotti M , Adams A , Dimitriadis G J 
Published: January 2004

Abstract Photobacterium damsela subsp. piscicida, the causative agent of fish pasteurellosis, was grown in vivo. Bacterial cells and extracellular products (ECPs) were analysed via electrophoresis and immunoblot analysis, using specific sea bass antisera. Growth in vivo induced the synthesis of unique bacterial cell proteins at >206, 206, 21.3, 18, 7.6 and <7.6 kDa. Sea bass serum raised against live bacterial cells of the pathogen and especially a sea bass serum raised against formalin‐inactivated bacterial cells grown in a specific novel medium recognized the novel antigens at >206 (associated with iron sequestration), 21.3, 7.6 and <7.6 kDa, suggesting that the latter medium conserves the synthesis of natural bacterial cell proteins in vitro. In vivo growth of the pathogen induced the synthesis of more toxic ECPs in comparison with in vitro growth and an inverse correlation between total protein concentration in the ECPs and toxicity per unit of protein was observed. Substrate‐polyacrylamide electrophoresis revealed the presence of in vivo synthesized ECPs of the pathogen (proteases) at 175, 132, <79 and 48.3 kDa. Histological examination of tissues isolated from fish injected with these ECPs revealed inflammatory and necrotic lesions in the spleen, liver, head kidney, intestine and heart as soon as 48 h post‐introduction of the ECPs.
Atlantic salmon, Salmo salar L., previously infected with Neoparamoeba sp. are not resistant to re‐infection and have suppressed phagocyte function
Authors: Gross K A , Morrison R N , Butler R , Nowak B F 
Published: January 2004

AbstractPrevious studies have indicated that Atlantic salmon, Salmo salar L., affected by amoebic gill disease (AGD) are resistant to re‐infection. These observations were based upon a comparison of gross gill lesion abundance between previously infected and naïve control fish. Anecdotal evidence from Atlantic salmon farms in southern Tasmania suggests that previous infection does not protect against AGD as indicated by a lack of temporal change in freshwater bathing intervals. Experiments were conducted to determine if previous infection of Atlantic salmon with Neoparamoeba sp. would provide protection against challenge and elucidate the immunological basis of any protection. Atlantic salmon were infected with Neoparamoeba sp. for 12 days then treated with a 4‐h freshwater bath. Fish were separated into two groups and maintained in either sea water or fresh water for 6 weeks. Fish were then transferred to one tank with a naïve control group and challenged with Neoparamoeba sp. Fish kept in sea water had lower mortality rates compared with first time exposed and freshwater maintained fish, however, these data are believed to be biased by ongoing mortalities during the seawater maintenance phase. Phagocyte function decreased over exposure time and freshwater maintained fish demonstrated an increased ability to mount a specific immune response. These results suggest that under the challenge conditions herein described, antigen exposure via infection does not induce protection to subsequent AGD.
Map‐based cloning of a fertility restorer gene, Rf‐1, in rice (Oryza sativa L.)
Authors: Komori Toshiyuki , Ohta Shozo , Murai Nobuhiko , Takakura Yoshimitsu , Kuraya Yoshiki , Suzuki Shoichi , Hiei Yukoh , Imaseki Hidemasa , Nitta Naoto 
Published: January 2004

SummaryA rice nuclear gene, Rf‐1, restores the pollen fertility disturbed by the BT‐type male sterile cytoplasm, and is widely used for commercial seed production of japonica hybrid varieties. Genomic fragments carrying Rf‐1 were identified by conducting chromosome walking and a series of complementation tests. Isolation and analysis of cDNA clones corresponding to the fragments demonstrated that Rf‐1 encodes a mitochondrially targeted protein containing 16 repeats of the 35‐aa pentatricopeptide repeat (PPR) motif. Sequence analysis revealed that the recessive allele, rf‐1, lacks one nucleotide in the putative coding region, presumably resulting in encoding a truncated protein because of a frame shift. Rice Rf‐1 is the first restorer gene isolated from cereal crops that has the property of reducing the expression of the cytoplasmic male sterility (CMS)‐associated mitochondrial gene like many other restorer genes. The present findings may facilitate not only elucidating the mechanisms of male sterility by the BT cytoplasm and its restoration by Rf‐1 but also isolating other restorer genes from cereal crops, especially rice.
Gain‐of‐function and loss‐of‐function phenotypes of the protein phosphatase 2C HAB1 reveal its role as a negative regulator of abscisic acid signalling
Authors: Saez Angela , Apostolova Nadezda , Gonzalez‐Guzman Miguel , Gonzalez‐Garcia Mary Paz , Nicolas Carlos , Lorenzo Oscar , Rodriguez Pedro L. 
Published: January 2004

Summary HAB1 was originally cloned on the basis of sequence homology to ABI1 and ABI2, and indeed, a multiple sequence alignment of 32 Arabidopsis protein phosphatases type‐2C (PP2Cs) reveals a cluster composed by the four closely related proteins, ABI1, ABI2, HAB1 and At1g17550 (here named HAB2). Characterisation of transgenic plants harbouring a transcriptional fusion ProHAB1: green fluorescent protein (GFP) indicates that HAB1 is broadly expressed within the plant, including key target sites of abscisic acid (ABA) action as guard cells or seeds. The expression of the HAB1 mRNA in vegetative tissues is strongly upregulated in response to exogenous ABA. In this work, we show that constitutive expression of HAB1 in Arabidopsis under a cauliflower mosaic virus (CaMV) 35S promoter led to reduced ABA sensitivity both in seeds and vegetative tissues, compared to wild‐type plants. Thus, in the field of ABA signalling, this work represents an example of a stable phenotype in planta after sustained overexpression of a PP2C genes. Additionally, a recessive T‐DNA insertion mutant of HAB1 was analysed in this work, whereas previous studies of recessive alleles of PP2C genes were carried out with intragenic revertants of the abi1‐1 and abi2‐1 mutants that carry missense mutations in conserved regions of the PP2C domain. In the presence of exogenous ABA, hab1‐1 mutant shows ABA‐hypersensitive inhibition of seed germination; however, its transpiration rate was similar to that of wild‐type plants. The ABA‐hypersensitive phenotype of hab1‐1 seeds together with the reduced ABA sensitivity of 35S:HAB1 plants are consistent with a role of HAB1 as a negative regulator of ABA signalling. Finally, these results provide new genetic evidence on the function of a PP2C in ABA signalling.
Identification of a mitochondrial external NADPH dehydrogenase by overexpression in transgenic Nicotiana sylvestris
Authors: Michalecka Agnieszka M. , Agius Stephanie C. , Møller Ian M. , Rasmusson Allan G. 
Published: January 2004

SummaryThe plant respiratory chain contains a complex setup of non‐energy conserving NAD(P)H dehydrogenases, the physiological consequences of which are highly unclear. An expression construct for the potato (Solanum tuberosum L., cv. Desiree) ndb1 gene, a homologue of bacterial and fungal type II NAD(P)H dehydrogenases, was introduced into Nicotiana sylvestris. Transgenic lines with high transcript and protein levels for St‐NDB1 had up to threefold increased activity of external NADPH dehydrogenase in isolated mitochondria as compared to the wild type (WT). In two lines, the external NADPH dehydrogenase activity was instead 10‐fold decreased, indicating that the corresponding N. sylvestris gene had been suppressed. Activities of external and internal rotenone‐insensitive NADH dehydrogenases were unchanged in the transgenic lines. The results demonstrate that the St‐ndb1 encodes an external dehydrogenase specific for NADPH and dependent on calcium for activity. Transgenic lines overexpressing St‐ndb1 had specifically increased protein levels for alternative oxidase and uncoupling protein, as compared to the WT and one co‐suppressing line. This indicates cross‐talk in the expressional control, or metabolic conditions influencing it, for the different categories of energy‐dissipating proteins that bypass oxidative phosphorylation. The potential effects of external NADPH oxidation on other cellular processes are discussed.
Definition and interactions of a positive regulatory element of the Arabidopsis INNER NO OUTER promoter
Authors: Meister Robert J. , Williams Luis A. , Monfared Mona M. , Gallagher Thomas L. , Kraft Edward A. , Nelson Christian G. , Gasser Charles S. 
Published: January 2004

Summary INNER NO OUTER (INO) expression is limited to the abaxial cell layer of the incipient and developing outer integument in Arabidopsis ovules. Using deletion analysis of the previously defined INO promoter (P‐INO), at least three distinct regions that contribute to the endogenous INO expression pattern were identified. One such positive element, designated POS9, which comprises at least three distinct subelements, was found to include sufficient information to duplicate the INO expression pattern when four or more copies were used in conjunction with a heterologous minimal promoter. While known regulators of INO, including INO, SUPERMAN, BELL1, and AINTEGUMENTA, did not detectably interact with POS9 in yeast one‐hybrid assays, two groups of proteins that interact specifically with POS9 were identified in one‐hybrid library screens. Members of one group include C2H2 zinc finger motifs. Members of the second group contain a novel, conserved DNA‐binding region and were designated the BASIC PENTACYSTEINE (BPC) proteins on the basis of conserved features of this region. The BPC proteins are nuclear localized and specifically bind in vitro to GA dinucleotide repeats located within POS9. The widespread expression patterns of the BPCs and the large number of GA repeat potential target sequences in the Arabidopsis genome indicate that BPC proteins may affect expression of genes involved in a variety of plant processes.
The Effect of Nitrogen Fertilization on Fusarium Head Blight Development and Deoxynivalenol Contamination in Wheat
Authors: Lemmens M. , Haim K. , Lew H. , Ruckenbauer P. 
Published: January 2004

AbstractThe impact of nitrogen (N) fertilization on the development of Fusarium head blight (FHB) in wheat and the resulting deoxynivalenol (DON) contamination in the kernels was studied. In a first experiment, the disease was assessed on two locations under natural infection pressure. Five different types of nitrogen fertilizer (both organic and mineral) were investigated, each applied at five input rates from 0 to 160 kg N/ha. With all fertilizers, a significant increase of disease intensity was observed with increasing N input, while the type of N fertilizer had poor or no effects on FHB. Depending on the fertilizer used, the percentage of diseased spikelets increased from 2.2% at zero N rate up to 6.6% at 160 kg N input per hectare. In a second series of trials, three spring wheat varieties including one Durum wheat line were artificially inoculated with a Fusarium graminearum and a F. culmorum strain, known producers of DON. A mineral N fertilizer was applied at five input levels from 0 to 160 kg N/ha. A significant increase in FHB intensity and DON contamination in the grain was observed with increasing N from 0 to 80 kg/ha. At higher input rates, relevant in contemporary crop husbandry, disease intensity and toxin contamination remained at constant levels. It is concluded that adaptation of N fertilization represents no relevant tool in managing FHB in practical wheat cultivation.