Systemic deletion of the myelin-associated outgrowth inhibitor Nogo-A improves regenerative and plastic responses after spinal cord injury

To investigate the role of the myelin-associated protein Nogo-A on axon sprouting and regeneration in the adult central nervous system (CNS), we generated Nogo-A-deficient mice. Nogo-A knockout (KO) mice were viable, fertile, and not obviously afflicted by major developmental or neurological disturbances. The shorter splice form Nogo-B was strongly upregulated in the CNS. The inhibitory effect of spinal cord extract for growing neurites was decreased in the KO mice. Two weeks following adult dorsal hemisection of the thoracic spinal cord, Nogo-A KO mice displayed more corticospinal tract (CST) fibers growing toward and into the lesion compared to their wild-type littermates. CST fibers caudal to the lesion-regenerating and/or sprouting from spared intact fibers-were also found to be more frequent in Nogo-A-deficient animals.     

Fiber-type specific and position-dependent expression of a transgene in limb muscles

We have previously shown that the proximal sequences of the human aldolase A fast-muscle-specific promoter (pM) are sufficient to target the expression of a linked CAT reporter gene to all fast, glycolytic trunk and limb muscles of transgenic mice (pM310CAT lines) in a manner mimicking the activity of the endogenous mouse promoter. When a NF1-binding site (motif M2) in this proximal regulatory region is mutated, the activity of the corresponding mM2 transgene is strongly affected but only in a some fast muscles. Here we show that the mutation of the M2 motif has only mild effects on pM activity in axial and proximal limb, while it drastically reduces this activity in both fore and hind limb distal muscles. At the cellular level, we show that both the pM310CAT and mM2 transgenes are highly expressed in fast glycolytic 2B fibers. However, by contrast to the pM310CAT transgene, whose expression is mainly restricted to fast glycolytic 2B fibers, the mM2 transgene is also active in a high proportion of 2X fibers. This result suggests that the M2 sequence could play a role in restricting the expression of pM to the 2B fibers. The variable expression of the mM2 transgene along the limb axis already exists at post-natal day 10 and seems to result from a change in the proportion of expressing fast fibers per muscle. Altogether, these results suggest that, although considered as phenotypically similar, different populations of fast glycolytic fibers exist, in which the requirement of the NF1 activity for pM expression varies according to the proximal versus distal position of the muscle along the limb axis.     

Functional characterization of three novel tissue-specific anion exchangers SLC26A7, -A8, and -A9

A second distinct family of anion exchangers, SLC26, in addition to the classical SLC4 (or anion exchanger) family, has recently been delineated. Particular interest in this gene family is stimulated by the fact that the SLC26A2, SLC26A3, and SLC26A4 genes have been recognized as the disease genes mutated in diastrophic dysplasia, congenital chloride diarrhea, and Pendred syndrome, respectively. We report the expansion of the SLC26 gene family by characterizing three novel tissue-specific members, named SLC26A7, SLC26A8, and SLC26A9, on chromosomes 8, 6, and 1, respectively. The SLC26A7-A9 proteins are structurally very similar at the amino acid level to the previous family members and show tissue-specific expression in kidney, testis, and lung, respectively. More detailed characterization by immunohistochemistry and/or in situ hybridization localized SLC26A7 to distal segments of nephrons, SLC26A8 to developing spermatocytes, and SLC26A9 to the lumenal side of the bronchiolar and alveolar epithelium of lung. Expression of SLC26A7-A9 proteins in Xenopus oocytes demonstrated chloride, sulfate, and oxalate transport activity, suggesting that they encode functional anion exchangers. The functional characterization of the novel tissue-specific members may provide new insights to anion transport physiology in different parts of body.     

Nogo-A expressed in Schwann cells impairs axonal regeneration after peripheral nerve injury

Injured axons in mammalian peripheral nerves often regenerate successfully over long distances, in contrast to axons in the brain and spinal cord (CNS). Neurite growth-inhibitory proteins, including the recently cloned membrane protein Nogo-A, are enriched in the CNS, in particular in myelin. Nogo-A is not detectable in peripheral nerve myelin. Using regulated transgenic expression of Nogo-A in peripheral nerve Schwann cells, we show that axonal regeneration and functional recovery are impaired after a sciatic nerve crush. Nogo-A thus overrides the growth-permissive and -promoting effects of the lesioned peripheral nerve, demonstrating its in vivo potency as an inhibitor of axonal regeneration.     

The Effect of Grain Preservatives on the Growth of the Fungus Fusarium Graminearum and on the Quantity of Zearalenone

In the present study, the effects of preservatives, “Luprosil®” (propionic acid) and “Gasol” (contains organic acids and some additional compounds) on the growth of mycelium and the toxin content of stored grain (oats) infected by Fusarium and containing zearalenone have been examined. The toxin quantity was determined before adding the preservatives quantitatively (by liquid chromatography) from the ether extracts of oats cultures and semiquantitatively (by bioassay) from the solid residues of the extracted grain cultures. The total amount of toxin in the contaminated grain was proved to be 2.5 mg per g of dry matter. Preservatives were added to the grain which contained 37 % of dry matter: “Luprosil®” 0.08 ml and “Gasol” 0.12 ml/g dry matter applying average or slightly high recommended doses. The two preservatives completely prevented the growth of a visible mycelium. Propionic acid (“Luprosil®”) had no influence on the toxin content of oats. “Gasol” decreased the percentage of the total toxin about 60 % in 3 days, 85 % in 14 days and 90 % in 28 days. Further investigations into this subject are now proceeding.     

Warm‐night temperature alters paternal allocation strategy in a North temperate‐zone butterfly

Warming temperatures are greatly impacting wild organisms across the globe. Some of the negative impacts of climate change can be mitigated behaviorally, for example, by changes in habitat and oviposition site choice. Temperatures are reportedly warming faster at night than during the day, yet studies assessing the impacts of increasing night temperature are rare. We used the Finnish Glanville fritillary butterfly (Melitaea cinxia) as study species and exposed adult butterflies of both sexes to warmer night conditions. Under a seminatural outdoor enclosure, we assessed whether females base their oviposition choices primarily on habitat site characteristics (open, suggestive of dry meadows, versus covered by a coarse canopy, suggestive of pastures) or on plant condition (dry vs. lush), and if their choice is altered by the thermal conditions experienced at night. As exposure to warmer environmental conditions is expected to increase resting metabolic rate and potentially reduce life expectancy, we further assessed the fitness implications of warm‐night temperatures. We found that females prefer open sites for oviposition and that females do not switch their oviposition strategy based on the thermal conditions they experienced at night prior to the reproductive event. Exposure to warm nights did not influence female lifespan, but the egg hatching success of their offspring was reduced. In addition, we found that males exposed to warm nights sired larger clutches with higher hatching rate. As warm‐night exposure reduced male lifespan, this may imply a switch in male resource allocation strategy toward increased offspring quality. The present work adds on to the complex implications of climate warming and highlights the importance of the often‐neglected role of males in shaping offspring performance.     

Elicitin genes in <Emphasis Type="Italic">Phytophthora infestans</Emphasis> are clustered and interspersed with various transposon-like elements

Sequencing and annotation of a contiguous stretch of genomic DNA (112.3 kb) from the oomycete plant pathogen Phytophthora infestans revealed the order, spacing and genomic context of four members of the elicitin (inf) gene family. Analysis of the GC content at the third codon position (GC3) of six genes encoded in the region, and a set of randomly selected coding regions as well as random genomic regions, showed that a high GC3 value is a general feature of Phytophthora genes that can be exploited to optimize gene prediction programs for Phytophthora species. At least one-third of the annotated 112.3-kb P. infestans sequence consisted of transposons or transposon-like elements. The most prominent were four Tc3/gypsy and Tc1/copia type retrotransposons and three DNA transposons that belong to the Tc1/mariner, Pogo and PiggyBac groups, respectively. Comparative analysis of other available genomic sequences suggests that transposable elements are highly heterogeneous and ubiquitous in the P. infestans genome.Electronic Supplementary Material Supplementary material is available for this article at     

Genetic transformation of Alstroemeria using particle bombardment

Transgenic plants were obtained after particle bombardment of embryogenic callus derived from stem segments of two tetraploid Alstroemeria genotypes with plasmids containing different selection/reporter genes. Firstly, a plasmid containing a firefly luciferase reporter gene driven by the maize ubiquitin promoter (Ubi1), was bombarded into both friable embryogenic callus and proembryos. Transient and stable expression of luciferase was visually detected by a luminometer. This selection method is non-destructive and can be applied over the whole developmental process from callus to embryo and plantlet. Molecular proof of transformation was obtained both by PCR analysis and Southern hybridization. Secondly, a plasmid containing the bar gene together with an uidA gene coding for -glucuronidase both driven by the Ubi1 promoter was bombarded into proembryos. The transgenic callus was effectively selected from the callus clumps four months after bombardment on a medium containing 5 mg/l phosphinotricin (PPT). Selection by PPT was efficient and labour-saving. Stable expression of GUS was confirmed by the histochemical staining assay and molecular proof was obtained by PCR analysis.     

A candidate locus for variation in dispersal rate in a butterfly metapopulation

Frequent extinctions of local populations in metapopulations create opportunities for migrant females to establish new populations. In a metapopulation of the Glanville fritillary butterfly (Melitaea cinxia), more mobile individuals are more likely to establish new populations, especially in habitat patches that are poorly connected to existing populations. Here we show that flight metabolic rate and the frequency of a specific allele of the metabolic enzyme phosphoglucose isomerase (pgi) were both highest in newly established, isolated populations. Furthermore, genotypes with this pgi allele had elevated flight metabolic rates. These results suggest that genetic variation in pgi or a closely linked locus has a direct effect on flight metabolism, dispersal rate, and thereby on metapopulation dynamics in this species. These results also contribute to an emerging understanding of the mechanisms by which population turnover in heterogeneous landscapes may maintain genetic and phenotypic variation across populations.     

Multivitamin production in Lactococcus lactis using metabolic engineering

The dairy starter bacterium Lactococcus lactis has the potential to synthesize both folate (vitamin B11) and riboflavin (vitamin B2). By directed mutagenesis followed by selection and metabolic engineering we have modified two complicated biosynthetic pathways in L. lactis resulting in simultaneous overproduction of both folate and riboflavin: Following exposure to the riboflavin analogue roseoflavin we have isolated a spontaneous mutant of L. lactis strain NZ9000 that was changed from a riboflavin consumer into a riboflavin producer. This mutant contained a single base change in the regulatory region upstream of the riboflavin biosynthetic genes. By the constitutive overproduction of GTP cyclohydrolase I in this riboflavin-producing strain, the production of folate was increased as well. Novel foods, enriched through fermentation using these multivitamin-producing starters, could compensate the B-vitamin-deficiencies that are common even in highly developed countries and could specifically be used in dietary foods for the large fraction of the Caucasian people (10-15%) with mutations in the methylene tetrahydrofolate reductase (MTHFR).