Genetic variations in the digestibility in sheep of selected whole-crop cereals used as silages

Whole-plant winter cereals could be of great interest if used as silages for ruminant feeding as opposed to summer crops in that they would spare water resources or valorize low-input management. This study aimed to compare the feeding value of rye, barley, wheat (two genotypes) and triticale (six genotypes). The cereals were sown in October and harvested as silage in June. Forages were offered to Texel castrated sheep in order to evaluate the organic matter digestibility (OMd). The OMd of the wheat cultivars was higher (61.6%, P<0.05) than those of barley (57.2%) and rye (54.7%) but no different from that of triticale (60.6%). Within the triticale genotypes, OMd ranged from 54.7 to 62.3%. The presence of rough barbs should explain the relatively low intake of the cereals with the exception of wheat. Winter cereals provide good-quality forage for feeding ruminants. Wheat has a higher nutritional value than barley and rye and a wide variability for digestibility seems to exist within the triticale cultivars. Such variability in a species known for its ability to be cropped under limiting conditions should be explored in much greater depth as it could result in providing farmers with genotypes of good quality with an acceptable yield at a lower cost.     

Health status in COPD cannot be measured by the St George's Respiratory Questionnaire alone: an evaluation of the underlying concepts of this questionnaire

Background

The definition of "clinical asthma remission" is based on absence of symptoms and use of medication. However, in the majority of these subjects airway inflammation is still present when measured. In the present study we investigated whether "complete asthma remission", additionally defined by the absence of bronchial hyperresponsiveness (BHR) and the presence of a normal lung function, is associated with the absence of airway inflammation.

Methods

Patients with a former diagnosis of asthma and a positive histamine provocation test were re-examined to identify subjects with complete asthma remission (no asthma symptoms or medication, PC₂₀ histamine > 32 mg/ml, FEV₁ > 90% predicted). Patients with PC₂₀ histamine ≤ 32 mg/ml were defined as current asthmatics and were divided in two groups, i.e. asthmatics with and without BHR to adenosine 5'monophoshate (AMP). Sputum induction was performed 1 week before and 1 hour after AMP provocation. Sputum induction and AMP provocation were previously shown to be sensitive markers of airway inflammation.

Results

Seven patients met criteria for complete asthma remission. Twenty-three were current asthmatics, including twelve without hyperresponsiveness to AMP. Subjects with complete asthma remission showed no AMP-induced sputum eosinophilia (median (range) 0.2 (0 - 4.6)% at baseline and 0.2 (0 - 2.6)% after AMP). After AMP, current asthmatics had a significant increase in sputum eosinophils (0.5 (0 - 26.0)% at baseline and 2.6 (0 - 32.0) % after AMP), as had the subgroup of current asthmatics without hyperresponsiveness to AMP (0.2 (0 - 1.8)% at baseline and 1.3 (0 - 6.3)% after AMP).

Conclusions

Subjects with complete asthma remission, in contrast to subjects with current asthma, do not respond with eosinophilic inflammation in sputum after AMP provocations. These data lend support to the usefulness of the definition of complete asthma remission.     

Neuroanatomical study of the A11 diencephalospinal pathway in the non-human primate

Background

The A11 diencephalospinal pathway is crucial for sensorimotor integration and pain control at the spinal cord level. When disrupted, it is thought to be involved in numerous painful conditions such as restless legs syndrome and migraine. Its anatomical organization, however, remains largely unknown in the non-human primate (NHP). We therefore characterized the anatomy of this pathway in the NHP.

Methods and Findings

In situ hybridization of spinal dopamine receptors showed that D1 receptor mRNA is absent while D2 and D5 receptor mRNAs are mainly expressed in the dorsal horn and D3 receptor mRNA in both the dorsal and ventral horns. Unilateral injections of the retrograde tracer Fluoro-Gold (FG) into the cervical spinal enlargement labeled A11 hypothalamic neurons quasi-exclusively among dopamine areas. Detailed immunohistochemical analysis suggested that these FG-labeled A11 neurons are tyrosine hydroxylase-positive but dopa-decarboxylase and dopamine transporter-negative, suggestive of a L-DOPAergic nucleus. Stereological cell count of A11 neurons revealed that this group is composed by 4002±501 neurons per side. A 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) intoxication with subsequent development of a parkinsonian syndrome produced a 50% neuronal cell loss in the A11 group.

Conclusion

The diencephalic A11 area could be the major source of L-DOPA in the NHP spinal cord, where it may play a role in the modulation of sensorimotor integration through D2 and D3 receptors either directly or indirectly via dopamine formation in spinal dopa-decarboxylase-positives cells.     

Variation in lignin and cell wall digestibility in caffeic acid O-methyltransferase down-regulated maize half-sib progenies in field experiments

Lignin content and structure were examined in seven caffeic acid O-methyltransferase antisense (COMT-AS) maize progenies and their corresponding normal inbred lines in relation to cell wall digestibility. The seven parental inbreds were chosen for their highly divergent in vitro wall digestibility. Maize plants were grown under field conditions to determine (i) if the positive effect of COMT down-regulation on wall chemistry and digestibility was similar to that previously observed for COMT-AS maize grown in the greenhouse and (ii) to what extent the genetic background was a factor in determining the effect of the transgene. All␣COMT-AS progenies displayed a significant reduction in endogenous COMT activity (14–43% residual activity). In all but one genetic background (F4), the COMT-AS gene resulted in an expected increase in wall digestibility accompanied by changes in lignin composition. These effects varied greatly among parental lines, and independently of the inherent digestibility values in the corresponding non-transformed lines. Curiously, in the highly digestible F4 background, the typical decrease in syringyl (S) unit lignin and a higher frequency of 5-OH guaiacyl lignin resulting from the introduction of the COMT-AS transgene were not observed. Our results indicate that COMT down-regulation via an antisense strategy is an efficient tool for forage maize improvement in the field.     

Gene selection algorithms for microarray data based on least squares support vector machine

Background  

In discriminant analysis of microarray data, usually a small number of samples are expressed by a large number of genes. It is not only difficult but also unnecessary to conduct the discriminant analysis with all the genes. Hence, gene selection is usually performed to select important genes.     

A new Arabidopsis thaliana mutant deficient in the expression of O-methyltransferase impacts lignins and sinapoyl esters

A promoter-trap screen allowed us to identify an Arabidopsis line expressing GUS in the root vascular tissues. T-DNA border sequencing showed that the line was mutated in the caffeic acid O-methyltransferase 1 gene (AtOMT1) and therefore deficient in OMT1 activity. Atomt1 is a knockout mutant and the expression profile of the AtOMT1 gene has been determined as well as the consequences of the mutation on lignins, on soluble phenolics, on cell wall digestibility, and on the expression of the genes involved in monolignol biosynthesis. In this mutant and relative to the wild type, lignins lack syringyl (S) units and contain more 5-hydroxyguaiacyl units (5-OH-G), the precursors of S-units. The sinapoyl ester pool is modified with a two-fold reduction of sinapoyl-malate in the leaves and stems of mature plants as well as in seedlings. In addition, LC-MS analysis of the soluble phenolics extracted from the seedlings reveals the occurrence of unusual derivatives assigned to 5-OH-feruloyl malate and to 5-OH-feruloyl glucose. Therefore, AtOMT1 enzymatic activity appears to be involved not only in lignin formation but also in the biosynthesis of sinapate esters. In addition, a deregulation of other monolignol biosynthetic gene expression can be observed in the Atomt1 mutant. A poplar cDNA encoding a caffeic acid OMT (PtOMT1) was successfully used to complement the Atomt1 mutant and restored both the level of S units and of sinapate esters to the control level. However, the over-expression of PtOMT1 in wild-type Arabidopsis did not increase the S-lignin content, suggesting that OMT is not a limiting enzyme for S-unit biosynthesis.these authors contributed equally to this workthese authors contributed equally to this work     

Down-regulation of the<Emphasis Type="Italic"> AtCCR1</Emphasis> gene in<Emphasis Type="Italic"> Arabidopsis thaliana</Emphasis>: effects on phenotype,lignins and cell wall degradability

Cinnamoyl CoA reductase (CCR; EC 1.2.1.44) is the first enzyme specific to the biosynthetic pathway leading to monolignols. Arabidopsis thaliana (L.) Heynh. plants transformed with a vector containing a full-length AtCCR1 cDNA in an antisense orientation were obtained and characterized. The most severely down-regulated homozygous plants showed drastic alterations to their phenotypical features. These plants had a 50% decrease in lignin content accompanied by changes in lignin composition and structure, with incorporation of ferulic acid into the cell wall. Microscopic analyses coupled with immunolabelling revealed a decrease in lignin deposition in normally lignified tissues and a dramatic loosening of the secondary cell wall of interfascicular fibers and vessels. Evaluation of in vitro digestibility demonstrated an increase in the enzymatic degradability of these transgenic lines. In addition, culture conditions were shown to play a substantial role in lignin level and structure in the wild type and in the effects of AtCCR1 repression efficiency.     

Nucleotide sequence ofbup,an upstream gene in thebmi-1 proviral insertion locus

The ability of Moloney murine leukemia virus to accelerate lymphomagenesis in E-myc transgenic mice is frequently associated with proviral integration within a locus denotedbmi-1. This locus contains not only thebmi-1 gene implicated as a collaborator withmyc in lymphomagenesis but also just upstream an unknown gene denotedbup. The nucleotide sequence reported here forbup cDNA and flanking genomic sequences reveals that this widely expressed gene comprises at least 7 exons and potentially encodes a polypeptide of 195 amino acid residues. Computer searches with this polypeptide sequence revealed no close homolog in the databases, nor any conserved motifs, and it is unrelated to the product of themel-13 gene, which lies just upstream from thebmi-1 homologmel-18.     

Improvement of motility of post-thaw Poitou jackass sperm using glutamine

The relative effectiveness of L-glutamine in preserving motility and movement characteristics of Poitou jackass spermatozoa diluted at 60 x 10(6) sperm/ml in INRA 82 medium modified by 4 % (v/v) glycerol and 2 % (v/v) quail's egg yolk during the cooling and freezing-thawing process was studied. After cooling to 4 degrees C, glutamine at 80, 120 or 240 mM did not improve the percentages of motile and progressively undulating spermatozoa or the movement characteristics (VCL = curvilinear velocity, VSL = straight line velocity, VAP = velocity of the average path, LIN = VSL/VCL x 100, ALH = amplitude of the lateral head displacement, BCF = beat cross frequency) assessed by the automated analyzer ATSM. However, after the FT process, 80 mM glutamine significantly improved motility, the percentage of progressively undulating spermatozoa and all the movement characteristics analyzed. The presence of glutamine at 80 mM in a glycerol-FT medium thus improves the motility of Poitou jackass spermatozoa during the freezing-thawing process. The presence of glutamine at 80 mM was not sufficient to offset the need to use glycerol in the freezing-thawing medium. This could indicate that glutamine has a mechanism of cryoprotection for Poitou jackass spermatozoa that is independant of glycerol.     

The carboxylic acid reduction pathway in Nocardia. Purification and characterization of the aldehyde reductase

Whole cultures of Nocardia sp. NRRL 5646 reduce carboxylic acids, first to aldehydes, then to alcohols and subsequently to the corresponding acetyl esters. This work describes an NADPH-dependent reductase responsible for catalyzing the reduction of aldehyde intermediates, which was purified 3240-fold by a combination of Mono-Q, hydroxyapatite, and ADP-agarose chromatographies. By sodium dodecyl sulfate–polyacrylamide gel electrophoresis, the purified enzyme ran as a single band of 47 kDa. A native molecular mass estimated at 101 kDa indicated that the enzyme was a homodimer in the native, active state. Edman degradation indicated a unique N-terminal sequence as NH₂-X-X-Ala-Ala-Ala-Tyr-Ala-Val-Pro-Ala-Pro-Asp-Gly-Cys-Phe-Glu-Lys-Val-Thr-Ile-Glu-Arg-Arg-Glu-Leu-Gly. The enzyme catalyzed reductions of many aryl- and alkyl-aldehyde substrates. Reactions were most favorable in the direction of aldehyde reduction to alcohols. Journal of Industrial Microbiology & Biotechnology (2000) 25, 328–332. Received 08 May 2000/ Accepted in revised form 20 October 2000