bluuebunny/crossref_metadata_2025_split huggingface dataset:
Citrus fruit bitter flavors: isolation and functional characterization of the gene Cm1,2RhaT encoding a 1,2 rhamnosyltransferase, a key enzyme in the biosynthesis of the bitter flavonoids of citrus
Authors: Frydman Ahuva , Weisshaus Oori , Bar‐Peled Maor , Huhman David V. , Sumner Lloyd W. , Marin Francisco R. , Lewinsohn Efraim , Fluhr Robert , Gressel Jonathan , Eyal Yoram 
Published: September 2004

SummarySpecies of the genus Citrus accumulate large quantities of flavanones that affect fruit flavor and have been documented to benefit human health. Bitter species, such as grapefruit and pummelo, accumulate bitter flavanone‐7‐O‐neohesperidosides responsible, in part, for their characteristic taste. Non‐bitter species, such as mandarin and orange, accumulate only tasteless flavanone‐7‐O‐rutinosides. The key flavor‐determining step of citrus flavanone‐glycoside biosynthesis is catalyzed by rhamnosyltransferases; 1,2 rhamnosyltransferases (1,2RhaT) catalyze biosynthesis of the bitter neohesperidosides, while 1,6 rhamnosyltransferases (1,6RhaT) catalyze biosynthesis of the tasteless rutinosides. We report on the isolation and functional characterization of the gene Cm1,2RhaT from pummelo which encodes a citrus 1,2RhaT. Functional analysis of Cm1,2RhaT recombinant enzyme was conducted by biotransformation of the substrates using transgenic plant cell culture. Flavanones and flavones, but not flavonols, were biotransformed into 7‐O‐neohesperidosides by the transgenic BY2 tobacco cells expressing recombinant Cm1,2RhaT. Immunoblot analysis established that 1,2RhaT protein was expressed only in the bitter citrus species and that 1,6RhaT enzyme, whose activity was previously documented in non‐bitter species, was not cross‐reactive. Expression of Cm1,2RhaT at the RNA level was prominent in young fruit and leaves, but low in the corresponding mature tissue, thus correlating well with the developmental pattern of accumulation of flavanone‐neohesperidosides previously established. Phylogenetic analysis of the flavonoid glycosyltransferase gene family places Cm1,2RhaT on a separate gene cluster together with the only other functionally characterized flavonoid‐glucoside rhamnosyltransferase gene, suggesting a common evolutionary origin for rhamnosyltransferases specializing in glycosylation of the sugar moieties of flavonoid glucosides.
Lesions in the mRNA cap‐binding gene ABA HYPERSENSITIVE 1 suppress FRIGIDA‐mediated delayed flowering in Arabidopsis
Authors: Bezerra Isabel C. , Michaels Scott D. , Schomburg Fritz M. , Amasino Richard M. 
Published: September 2004

SummaryRecessive mutations that suppress the late‐flowering phenotype conferred by FRIGIDA (FRI) and FLOWERING LOCUS C (FLC) and which also result in serrated leaf morphology were identified in T‐DNA and fast‐neutron mutant populations. Molecular analysis showed that the mutations are caused by lesions in the gene encoding the large subunit of the nuclear mRNA cap‐binding protein, ABH1 (ABA hypersensitive1). The suppression of late flowering is caused by the inability of FRI to increase FLC mRNA levels in the abh1 mutant background. The serrated leaf morphology of abh1 is similar to the serrate (se) mutant and, like abh1, se is also a suppressor of FRI‐mediated late flowering although it is a weaker suppressor than abh1. Unlike se, in abh1 the rate of leaf production and the number of juvenile leaves are not altered. The abh1 lesion affects several developmental processes, perhaps because the processing of certain mRNAs in these pathways is more sensitive to loss of cap‐binding activity than the majority of cellular mRNAs.
Affinity purification of the tobacco plastid RNA polymerase and in vitro reconstitution of the holoenzyme
Authors: Suzuki Jon Y. , Jimmy Ytterberg A. , Beardslee Thomas A. , Allison Lori A. , van Wijk Klaas Jan , Maliga Pal 
Published: September 2004

SummaryWe affinity‐purified the tobacco plastid‐encoded plastid RNA polymerase (PEP) complex by the α subunit containing a C‐terminal 12 x histidine tag using heparin and Ni2+ chromatography. The composition of the complex was determined by mass spectrometry after separating the proteins of the >900 kDa complex in blue native and SDS polyacrylamide gels. The purified PEP contained the core α, β, β′, β′′ subunits and five major associated proteins of unknown function, but lacked sigma factors required for promoter recognition. The holoenzyme efficiently recognized a plastid psbA promoter when it was reconstituted from the purified PEP and recombinant plastid sigma factors. Reconstitution of a plastid holoenzyme with individual sigma factors will facilitate identification of sigma factor‐specific promoter elements.
Crosstalk between elicitor‐induced cell death and cell cycle regulation in tobacco BY‐2 cells
Authors: Kadota Yasuhiro , Watanabe Takashi , Fujii Shinsuke , Higashi Katsumi , Sano Toshio , Nagata Toshiyuki , Hasezawa Seiichiro , Kuchitsu Kazuyuki 
Published: September 2004

SummaryThe molecular links between cell cycle control and the regulation of programmed cell death are largely unknown in plants. Here we studied the relationship between the cell cycle and elicitor‐induced cell death using synchronized tobacco BY‐2 cells. Flow cytometry and fluorescence microscopy of nuclear DNA, and RNA gel‐blot analyses of cell cycle‐related genes revealed that the proteinaceous elicitor cryptogein induced cell cycle arrest at the G1 or G2 phase before the induction of cell death. Furthermore, the patterns of cell death induction and defence‐related genes were different in different phases of the cell cycle. Constitutive treatment with cryptogein induced cell cycle arrest and cell death at the G1 or G2 phase. With transient treatment for 2 h, cell cycle arrest and cell death were only induced by treatment with the elicitor during the S or G1 phase. By contrast, the elicitor‐induced production of reactive oxygen species was observed during all phases of the cell cycle. These results indicate that although recognition of the elicitor signal is cell cycle‐independent, the induction of cell cycle arrest and cell death depends on the phase of the cell cycle.
Genetic parameters of racing merit of thoroughbred horses in Poland
Authors: Sobczynska M. , Lukaszewicz M. 
Published: September 2004

SummaryThe study aimed at estimating variance components of racing ability traits in thoroughbred horses as a contribution to defining the breeding objective for this breed. Data collected were 12 143 placings at finish (square root) and 8641 earnings (log) won by 1414 horses running in 1693 races over the period of 1998–2001. Age of horses ranged from 2 to 5+ years, and the distances were from 1000 to 3200 m. Horses were from 11 state stables, from private breeders (one collective group), and from foreign breeding (another collective group within the factor ‘breeder’). Variance components were estimated by the residual maximal likelihood (REML) method. Statistical analysis accounted for fixed effects of year, age, race, breeder (optional), sex, weight carried and distance, and for the random effects of rider, permanent environment, and animal additive genetics. Pedigrees were at least three generations deep. When breeder effect was excluded from the model, heritability coefficients were 0.12 and 0.18, repeatability 0.23 and 0.34 for earnings and placings at finish, respectively.
Mitochondrial DNA variation and genetic relationships in Spanish donkey breeds (Equus asinus)
Authors: Aranguren‐Mendez J. , Beja‐Pereira A. , Avellanet R. , Dzama K. , Jordana J. 
Published: September 2004

SummaryIn this study, the mitochondrial DNA diversity of six Spanish donkey breeds and two African donkey populations (one from Morocco and the other from Zimbabwe) was analysed. A total of 79 animals were sequenced for 313 bp of the cytochrome b gene, and 91 individuals for 383 bp of the D‐loop region or control‐region. Sequence comparisons and phylogenetic analyses of both Spanish and African populations revealed low diversity. Only six and seven haplotypes respectively were found in cytochrome b and the D‐loop region. Relatively low nucleotide diversity (π) values were detected in these populations. The π values, from the D‐loop region, ranged from 0.0006 to 0.0169 for the Catalana and Andaluza breeds, respectively. The obtained results seem to confirm the existence of two divergent maternal lineages of African origin (Equus asinus africanus and E. a. somaliensis). In this paper the genetic relationships between these breeds are analysed and compared with those obtained in other European populations. Also, the data on the genetic relationships between the populations, obtained from nuclear DNA (microsatellites) and mitochondrial DNA (cytochrome b and D‐loop region) is argued and interpreted.
Genetic diversity of Chinese indigenous goat breeds based on microsatellite markers
Authors: Xiang‐Long Li , Valentini Alessio 
Published: September 2004

SummaryEighteen microsatellites were used to investigate the genetic diversity and differentiation of eight Chinese indigenous goat breeds. The results indicated that there is a significant difference of genetic diversity between different loci. Chinese indigenous goat breeds have similar genetic diversity to other Asian goats, but with lower Fst. The clustering of individuals and populations showed that Chinese indigenous goat breeds might have originated from two ancestral populations. The genetic differentiation between populations is consistent with the results of archaeology, mtDNA and RAPD.
Muscle fibre traits as additional selection criteria for muscle growth and meat quality in pigs – results of a simulated selection
Authors: Fiedler I. , Dietl G. , Rehfeldt C. , Wegner J. , Ender K. 
Published: September 2004

SummaryTo estimate the direct and correlated responses in meatiness and meat quality, simulated selection was applied using one‐trait selection and index selection including muscle fibre traits. In a total of 2024 pigs of German Landrace, Large White, Leicoma, and Schwerfurter breeds, carcass composition, meat quality, and fibre characteristics of the M. longissimus lumborum were analysed and genetic parameters were calculated by using REML variance component estimation. Coefficients of heritability ranged from low to moderate (growth traits: h2 = 0.22–0.32; meat quality traits: h2 = 0.17–0.27; muscle fibre traits: h2 = 0.12–0.20). The total fibre number and the frequency of white fibres correlated positively with live weight (rg = 0.44 and 0.44, respectively) and with loin muscle area (rg = 0.38 and 0.19, respectively) while the relationships to pH value and drip loss were not as close (rg = −0.29–0.19). Selection indices were constructed from live weight and muscle area, from pH value and drip loss, and from muscle structure traits. As expected, simulated selection for live weight or loin muscle area lead to direct positive effects but these were associated with negative effects on meat quality traits (selection intensities: SI = 0.1; 0.5). Using selection for an index from loin area and muscle structure (loin muscle area + total fibre number – frequency of white fibres – frequency of giant fibres) the adverse effect on meat quality was minimized (responses in pH value: −0.05; −0.01) or was changed towards desired direction (responses in drip loss: −0.65%; −0.26%). The results show that fibre characteristics of pig muscle can be used as selection criteria for simultaneous improvement of carcass composition and meat quality in pigs by including indices developed from performance and fibre traits.
Top down preselection using marker assisted estimates of breeding values in dairy cattle
Authors: Bennewitz Jörn , Reinsch Norbert , Reinhardt Friedrich , Liu Zengting , Kalm Ernst 
Published: September 2004

SummaryTop down preselection of young bulls before entering progeny testing has been proposed as a practicable form of marker‐assisted selection (MAS), especially in dairy cattle populations with large male paternal half‐sib families. Linkage phase between the superior (Q) and the inferior (q) QTL alleles of heterozygous sires (Qq at the QTL) with informative markers is established within each paternal half‐sib family and may be used for selection among grand‐progeny. If, additionally to sires, bulldams are also genotyped and data from consecutive generations are used, then a marker‐assisted best linear unbiased prediction (MA‐BLUP) model can be employed to connect the information of all generations and families of a top down design, and to select across all families. A customized ‘augmented’ sire model (with sires and dams of sires as random effects) is introduced for this purpose. Adapted formulae for the mixed model equations are given and their equivalence to a corresponding animal model and to a certain variant of previously proposed reduced animal models is shown. The application of the augmented sire model in MA‐BLUP estimation from daughter‐yield deviations and effective daughter contributions is presented.
Differential transcription of the bovine AMPD3 gene in single blastocysts cultured under various oxygen tensions
Authors: Yuan Y. Q. , Peelman L. J. , Williams J. L. , Van Zeveren A. , de Kruif A. , Law A. , Van Soom A. 
Published: September 2004

SummaryStudying gene expression during the early embryonic stages of in vitro culture is essential and of special interest, not only to gain insights in embryo development but also to find candidate genes that can be used as markers to assess embryo quality. Using differential display RT‐PCR expression of AMPD3 coding for AMP deaminase 3 was found in bovine blastocysts cultured in vitro only under 2% but not under 5 and 20% oxygen tensions. Mapping of this gene to bovine chromosome 15 confirmed its identity. The differential expression of bovine AMPD3 was confirmed by RT‐PCR with specific primers.
Variance component estimation on the frequency of pathologic changes in the navicular bones of Hanoverian Warmblood horses
Authors: Stock K. F. , Hamann H. , Distl O. 
Published: September 2004

SummaryThe results of a standardized radiological examination of 3748 young Hanoverian Warmblood horses selected for sale at auction as riding horses were used to quantify the influence of systematic effects on and to estimate genetic parameters for the prevalence of pathologic changes in the navicular bones. Radiographic findings in the navicular bones of the front limbs were analyzed as all‐or‐none traits. The pathologic changes were mostly classified as slight [PCN(I); 14.9%], less often as moderate [PCN(II); 5.3%] or severe [PCN(III); 1.8%]. Date and year of auction had a significant influence on the prevalence of documented radiographic findings. The prevalence of PCN(I) was further significantly dependent on the examiner, the type and the quality of auction. PCN(II) was significantly more prevalent in male than in female horses. The age, the anticipated suitability and the region of origin of the horses did not have any significant influence on the prevalence of pathologic changes in navicular bones. A higher percentage of genes of the Hanoverian and the Holstein Warmblood horse increased the probability of PCN(I) classification. A significant influence of the sire was found for PCN(I) and PCN(II), and of the male founder for PCN(II) and PCN(III). The female founder was significant only for PCN(II). In general, radiographic findings of any severity in front left and right navicular bones were significantly correlated with each other. Restricted maximum likelihood (REML) was used for the estimation of genetic parameters. The analyses were performed multivariately in linear animal and sire models including height at withers as a separate trait. Heritability estimates for the prevalence of PCN(I), PCN(II) and PCN(III) of horses of both sexes ranged between h2 = 0.09 and 0.21. When distinguishing between findings in males and females, somewhat implausible estimates were obtained for PCN(II) in females, which might have been caused by their low prevalence. The additive genetic correlations between the investigated traits indicated that radiographic findings consistent with navicular syndrome have a uniform genetic pattern in males and in females, and irrespective of their severity. However, their genetic correlation to height at withers was found to be inconsistent and, therefore, not to be utilizable for selection.
Characterization and applications of an expanded canine BAC library with fourfold genome coverage
Authors: Schelling C. , Billault A. , Colomb B. , Pineroli B. , Guziewicz K. , Piasecka A. , Gmür A. , Klukowska J. , Gaillard C. , Stranzinger G. , Dolf G. 
Published: September 2004

SummaryAn existing canine genomic bacterial artificial chromosome (BAC) library was expanded by adding 115 200 clones with insert lengths not yet represented or under‐represented. The final version of the library consists of 211 968 clones with an estimated average insert size of 110 000 base pairs. Clones were grown individually and glycerol permanents were arrayed in 2208 96‐well microtitre plates. DNA of each clone was prepared by microwave treatment and organized in a three‐dimensional DNA pooling system (92 superpools) allowing for rapid screening by polymerase chain reaction (PCR). Screening of the library for 111 microsatellite loci representing all canine chromosomes revealed a recovery rate of 93% and a fourfold genome coverage. In addition, 50 BAC clones containing microsatellites or genes related to ongoing projects in the laboratories of the authors and eight other research groups were successfully recovered. The present library is the first canine BAC library amenable to PCR screening and is an invaluable tool for cloning candidate loci and developing genetic markers in specific chromosomal regions. This library will also enhance mapping efforts in related canid species and is an important source for geneticists studying inherited diseases common to both dog and humans. Interested researchers can access the library following the instructions at http://www.dogmap.ch.
Malignant Mixed Sex Cord‐stromal Tumour in a Stallion
Authors: Zanghì A , Catone G , Marino G , De Vico G , Nicòtina PA 
Published: September 2004

ContentsA 30‐year‐old Standardbred stallion was examined for unilateral scrotal swelling. Physical and ultrasound examinations revealed a painless enlarged left testis with a non‐homogeneous echogenicity, when compared with the controlateral testis. The stallion underwent left unilateral orchiectomy. Grossly, the excised testis was irregularly enlarged (12 × 9 × 9 cm; weight: 530 g) and firm. The sections showed that testicular parenchyma was replaced by a lobulated, greyish‐white mass, which involved the epididymal head. At microscopy, a dual Leydig and Sertoli cell tumour component could be seen. Neoplastic Sertoli cells were prevalent and presented pleomorphic cells, mitotic figures and occasional vascular invasion. Tumour patterns showed tubular and solid areas, cord‐like or diffuse in appearance, among which newly formed Leydig cell nests and low‐density fibrillar bundles were interposed. Immunohistochemically, a weak to moderate immunostaining for vimentin, AE1/AE3 cytokeratin, α‐1‐antitrypsin and CD99 antigens was found in the growing Sertoli cells, whose nuclear MIB‐1 labelling index scored 13 ± 2%. The Leydig tumour cells, on the other hand, displayed a moderate to strong positivity for α‐inhibin, vimentin, AE1/AE3 cytokeratin, neurone‐specific enolase and CD99. On the basis of these findings, a diagnosis of malignant mixed sex cord‐stromal tumour was made.
Pituitary Hormone Responses to Luteal Regression after Administration of Prostaglandin F2α‐Analogue
Authors: Hori T , Kawakami E , Tsutsui T 
Published: September 2004

ContentsAs an experiment to elucidate the canine luteal function maintenance system, a PGF2α‐analogue, fenprostalene (PGF‐F), was administered 24 and 54 days after ovulation to induce luteal regression, and the responses of luteinizing hormone (LH) and prolactin (PRL), which are considered to support the canine corpus luteum, were investigated. The plasma progesterone (P4) level was rapidly decreased, by which the plasma PRL level was increased, but no change was observed in the plasma LH level. The decrease in the plasma P4 level after PGF‐F administration may have induced positive feedback to the superior system, and stimulated secretion of the pituitary hormones. These findings suggested that the canine corpus luteum is maintained by PRL, not by LH.
The Predictive Value of Porcine Seminal Parameters on Fertility Outcome under Commercial Conditions
Authors: Gadea J , Sellés E , Marco MA 
Published: September 2004

ContentsThe aim of this study was to address the question of whether differences in farrowing rate and litter size after the use of different ejaculates could be predicted using the standard semen parameters under commercial conditions. In this study, a total of 1818 sows were used to evaluate the fertility predictive value of different sperm parameters. Logistic regression analysis (univariate and multivariate) was used to correlate the dichotomous farrowing rate data to the sperm parameters. Linear regression was also used to determine the relationship between litter size and semen parameters (Pearson correlation and multiple regression). Receiver‐operating curves (ROC) were used to determine the overall performance characteristics of each semen variable in the logistic regression model. Semen analysis, under commercial conditions, allows to identify ejaculates with very low fertility potential but the pre‐selection of the samples, the high number of sperm per doses and the high quality of the semen used in artificial insemination (AI) programmes reduces the variability. Therefore, it is unlikely to detect fertility differences associated with seminal parameters.
Selenium Status and GSH‐Px Activity in Semen and Blood of Boars at Different Ages Used for Artificial Insemination
Authors: Lasota B , Błaszczyk B , Seremak B , Udała J 
Published: September 2004

ContentsThis study was performed to determine the relationship between selenium (Se) content and Se‐dependent glutathione peroxidase (GSH‐Px) activity in blood and semen, and semen quality of boars at different age used in an artificial insemination (AI) station. Routine macroscopic and microscopic analyses of semen quality were accompanied by measurement of Se content and GSH‐Px activity in blood and semen. The Se concentration in blood plasma, seminal fluid and spermatozoa was measured by fluorometric method, the GSH‐Px activity by a method based on NADPH‐coupled reaction. A total of 155 ejaculates and 58 blood samples were investigated. The results of this study showed that there was no direct relationship between the Se content and GSH‐Px activity in blood plasma and semen, and semen quality of sexual matured boars. The mechanisms controlling Se content and GSH‐Px activity in blood and semen seem to be independent. The age of boars as a differentiating factor for Se content and GSH‐Px activity in blood and semen is possible. It is concluded that a determination of Se status and/or GSH‐Px activity in organism before Se supplementation is indicated.