A linkage map of meadow fescue (<Emphasis Type="Italic">Festuca pratensis</Emphasis> Huds.) and comparative mapping with other Poaceae species

A genetic linkage map has been constructed for meadow fescue (Festuca pratensis Huds.) (2n=2x=14) using a full-sib family of a cross between a genotype from a Norwegian population (HF2) and a genotype from a Yugoslavian cultivar (B14). The two-way pseudo-testcross procedure has been used to develop separate maps for each parent, as well as a combined map. A total number of 550 loci have been mapped using homologous and heterologous RFLPs, AFLPs, isozymes and SSRs. The combined map consists of 466 markers, has a total length of 658.8 cM with an average marker density of 1.4 cM/marker. A high degree of orthology and colinearity was observed between meadow fescue and the Triticeae genome(s) for all linkage groups, and the individual linkage groups were designated 1F–7F in accordance with the orthologous Triticeae chromosomes. As expected, the meadow fescue linkage groups were highly orthologous and co-linear with Lolium, and with oat, maize and sorghum, generally in the same manner as the Triticeae chromosomes. It was shown that the evolutionary 4AL/5AL translocation, which characterises some of the Triticeae species, is not present in the meadow fescue genome. A putative insertion of a segment orthologous to Triticeae 2 at the top of 6F, similar to the rearrangement found in the wheat B and the rye R genome, was also observed. In addition, chromosome 4F is completely orthologous to rice chromosome 3 in contrast to the Triticeae where this rice chromosome is distributed over homoeologous group 4 and 5 chromosomes. The meadow fescue genome thus has a more ancestral configuration than any of the Triticeae genomes. The extended meadow fescue map reported here provides the opportunity for beneficial cross-species transfer of genetic knowledge, particularly from the complete genome sequence of rice.Communicated by P. Langridge     

Relationship between the association of rat epididymal protein "DE" with spermatozoa and the behavior and function of the protein

Rat epididymal glycoprotein DE associates with the dorsal region of the sperm head during sperm maturation, migrates to the equatorial segment (ES) with the acrosome reaction (AR), and is involved in gamete membrane fusion. In the present study we examined the association of DE with the sperm surface and the relationship of this interaction with the behavior and function of the protein. Cloning and sequencing of DE revealed a lack of hydrophobic domains and the presence of 16 cysteine residues in the molecule. Experiments in which cauda epididymal sperm were subjected to different extraction procedures indicated that while most of the protein is removable from sperm by mild ionic strength, a low amount of DE, resistant to even 2 M NaCl, can be completely extracted by agents that remove integral proteins. However, the lack of hydrophobic domains in the molecule and the failure of DE to interact with liposomes, does not support a direct insertion of the protein into the lipid bilayer. These results, and the complete extraction of the tightly bound protein by dithiothreitol, suggest that this population would correspond to a peripheral protein bound to a membrane component by strong noncovalent interactions that involve disulfide bonds. While ELISA experiments showed that no protein could be extracted by NaCl from capacitated sperm, indirect immunofluorescence studies revealed the ability of the NaCl-resistant protein to migrate to the ES. Together, these results support the existence of two populations of DE: a major, loosely bound population that is released during capacitation, and a minor strongly bound population that remains after capacitation, migrates to the ES with the AR, and thus would correspond to the one with a role in gamete fusion.     

Characterization and correlations of behavioral and adrenocortical activities of zoo‐housed lesser anteaters (Tamandua tetradactyla)

We characterized behavioral and adrenocortical activities of Tamandua tetradactyla under human care driven by the hypothesis that they vary between males and females. We also assessed the potential association between natural or abnormal behaviors and adrenocortical activity. We kept females and males T. tetradactyla in individual, contiguous enclosures at Córdoba Zoo (Argentina), under natural photoperiod and temperature. During 29 consecutive days we monitored the animals’ behavior by recording their activity pattern every 5 min using infrared cameras (8352 records/individual). We collected all feces and measured fecal glucocorticoid metabolites (FGM) with an 11‐oxoaetiocholanolone enzyme immunoassay. We found individual differences in all behavioral variables. We detected that females exhibited lower total activity than males (23.8 ± 0.2% and 32.3 ± 0.3%, respectively; p = .005). Females were more active at night and males during the day (p < .05) and exhibited less abnormal behaviors than males (p = .05). Although we did not find sex‐related differences for average FGM, we detected individual differences (p < .0001). We found that daily FGM showed negative (?0.39) and positive (0.38) correlations with natural and abnormal behaviors, respectively (p < .0001). Thus, we consider that individual input and sex are factors to be considered in stress responses of the species in captivity. Natural and abnormal behaviors may demand different levels of adrenocortical activity. Our findings may prove useful as normative data for ex situ management of conservation programs.     

Dendritic Cells Cause Bone Lesions in a New Mouse Model of Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease caused by the clonal accumulation of dendritic Langerhans cells, which is often accompanied by osteolytic lesions. It has been reported that osteoclast-like cells play a major role in the pathogenic bone destruction seen in patients with LCH and these cells are postulated to originate from the fusion of DCs. However, due to the lack of reliable animal models the pathogenesis of LCH is still poorly understood. In this study, we have established a mouse model of histiocytosis- recapitulating human disease for osteolytic lesions seen in LCH patients. At 12 weeks after birth, severe bone lesions were observed in our multisystem histiocytosis (Mushi) model, when CD8α conventional dendritic cells (DCs) are transformed (MuTuDC) and accumulate. Most importantly, our study demonstrates that bone loss in LCH can be accounted for the transdifferentiation of MuTuDCs into functional osteoclasts both in vivo and in vitro. Moreover, we have shown that injected MuTuDCs reverse the osteopetrotic phenotype of oc/oc mice in vivo. In conclusion, our results support a crucial role of DCs in bone lesions in histiocytosis patients. Furthermore, our new model of LCH based on adoptive transfer of MuTuDC lines, leading to bone lesions within 1–2 weeks, will be an important tool for investigating the pathophysiology of this disease and ultimately for evaluating the potential of anti-resorptive drugs for the treatment of bone lesions.     

Enhanced expression of genes involved in coagulation and fibrinolysis in murine arthritis

We have analyzed the pattern of procoagulant and fibrinolytic gene expression in affected joints during the course of arthritis in two murine models. In both models, we found an increased expression of tissue factor, tissue factor pathway inhibitor, urokinase plasminogen activator, and plasminogen activator inhibitor 1, as well as thrombin receptor. The observed pattern of gene expression tended to favor procoagulant activity, and this pattern was confirmed by functional assays. These alterations would account for persistence of fibrin within the inflamed joint, as is seen in rheumatoid arthritis.     

A systems model of training responses and its relationship to hormonal responses in elite weight-lifters

A systems model, providing an estimation of fatigue and fitness levels was applied to a 1-year training period of six elite weight-lifters. The model parameters were individually determined by fitting the predicted performance (calculated as the difference between fitness and fatigue) to the actual one. The purpose of this study was to validate the systems model by comparing the estimated levels of fatigue and fitness with biological parameters external to the model calculation. The predicted and the actual performances were significantly correlated in each subject. The calculated fitness and fatigue levels were related to serum testosterone concentration, testosterone: cortisol and testosterone: sex hormone binding globulin ratios. The best results were obtained by the comparison between fitness and testosterone levels, which varied in parallel in each subject. In two subjects this correlation was significant (r = 0.91, P less than 0.05, and r = 0.92, P less than 0.01). The fitness changes calculated in each subject between the 15th and the 51st weeks of training were significantly correlated with the changes in serum testosterone concentration measured in the same period (r = 0.99, P less than 0.001). For the whole group testosterone and fitness variations were also significantly intercorrelated (r = 0.73, P less than 0.001). Correlations, less homogeneous and less significant, were calculated also for other hormones and ratios. These results suggest that (1) the relationships between training and performance can be described by the systems model, (2) the estimated index of fitness has a physiological meaning. The fatigue index remains to be clarified.     

The structure of cyclin H: common mode of kinase activation and specific features.

The crystal structure of human cyclin H refined at 2.6 A resolution is compared with that of cyclin A. The core of the molecule consists of two repeats containing five helices each and forming the canonical cyclin fold also observed in TFIIB. One hundred and thirty-two out of the 217 C alpha atoms from the cyclin fold can be superposed with a root-mean-square difference of 1.8 A. The structural homology is even higher for the residues at the interface with the kinase, which is of functional significance, as shown by our observation that cyclin H binds to cyclin-dependent kinase 2 (cdk2) and that cyclin A is able to activate cdk7 in the presence of MAT1. Based on this superposition, a new signature sequence for cyclins was found. The specificity of the cyclin H molecule is provided mainly by two long helices which extend the cyclin fold at its N- and C-termini and pack together against the first repeat on the side opposite to the kinase. Deletion mutants show that the terminal helices are required for a functionally active cyclin H.     

Reproduction in chinchilla (Chinchilla lanigera): current status of environmental control of gonadal activity and advances in reproductive techniques

In female swine, PGF2α is an important regulator of corpora luteal (CL) function, uterine contractility, ovulation, and embryo attachment. High affinity PGF2α receptors are present in the CL at all stages of the estrous cycle and they are functional. Therefore, a lack of luteolytic capacity of PGF2α is related to other factors that have not been well identified. In female pigs, a single exogenous PGF2α injection produces a short lasting decrease in plasma progesterone levels but does not induce luteolysis before day 12 of the estrous cycle. However, multiple injections of PGF2α can induce luteolysis before day 12 of the estrous cycle and may be utilized in the development of protocols for ovulation synchronization and timed AI. Most commonly, PGF2α is used for the induction of farrowing and so facilitation of cross fostering. Further, since PGF2α is a smooth muscle stimulant, treatment to stimulate myometrial contractions and uterine evacuation of residual products from parturition or infectious debris, may have beneficial effects on post-weaning fertility. Administration of PGF2α at the moment of insemination has been shown to improve reproductive performances when fertility is otherwise low, such as in sow under summer heat stress.     

A Kinetic Study of the Main Guaco Metabolites Using Syrup Formulation and the Identification of an Alternative Route of Coumarin Metabolism in Humans

For decades guaco species have been empirically used for the treatment of respiratory diseases. However, studies have shown that the toxic and therapeutic effects of the main guaco metabolites are dose-dependent, and none clinical study was done to evaluate the behavior of these substances in humans. In this work, a pilot study measuring the kinetic profile of the main guaco metabolites was performed leading to the knowledge of an alternative route of coumarin metabolism in humans. Initial screenings demonstrated that the administration of 60 mL of guaco syrup (single dose) did not provide sufficient levels of coumarin (COU), 7-hydroxycoumarin (7-HCOU), o-coumaric acid (OCA) and kaurenoic acid (KAU). The pharmacokinetic parameters were calculated by orally administering 60 mL of guaco syrup spiked with 1500 mg of COU. The kinetic study demonstrated that the plasmatic levels of 7-HCOU (considered the main metabolite of COU) were 10 times lower than the levels of COU, and the kinetic profile of 7-HCOU suggests sequential metabolism in the liver with low access of 7-HCOU to the systemic circulation. The study also demonstrated that OCA is one of the main bioavailable metabolites of COU. Therefore, the hydrolysis of the lactone ring forming a carboxylated compound is one of the possible routes of COU metabolism in humans. The half-lives of COU, 7-HCOU and OCA were approximately 4.0, 1.0 and 3.0 h, respectively and there was evidence that the recommended dosage of guaco syrup did not provide sufficient levels of COU, 7-HCOU or OCA to obtain a bronchodilation effect. Clinical studies are necessary to prove the efficacy and safety of products based on guaco.     

Plasminogen activators in the mouse mammary gland. Decreased expression during lactation

The enzyme content and mRNA level for both urokinase-type and tissue-type plasminogen activators have been explored during the life cycle of the adult mouse mammary gland. Both enzymes were detected, and urokinase-type plasminogen activator was the predominant form. A marked decrease in enzyme content occurred in late gestation and was maintained throughout lactation; upon weaning, the enzyme content returned to the levels found in virgin mice. These effects were entirely accounted for by changes in the respective mRNA concentrations, which were determined with respect to both total tissue RNA and poly(A+) mRNA. Thus, plasminogen activator-catalyzed proteolysis may occur at high levels throughout the life cycle of the mouse mammary gland, except during lactation.