Lack of dynein arms in immotile human spermatozoa.

Sermatozoa from two brothers who are not twins were found to be straight and immotile. Examinations of the sperm showed that oxygen consumption and lactic acid production were normal; viability tests showed that the percentage of dead sperm was not increased. The ultrastructural appearance of the sperm tail was normal except for a complete lack of dynein arms and some irregularities in the arrangement of the accessory fibers and the longitudinal columns of the fibrous sheath. The mitochondrial apparatus and the sperm head conform to the conventional model. According to the sliding-filament hypothesis first proposed by Afzelius (1959. J. Biophys. Biochem. Cytol. 5:269.), the arms are responsible for the bending movements of the tail. The simplest explanation for the simultaneous lack of arms and sperm motility appears to be that the two brothers have a genetic disorder involving production, assembly, or attachment of the dynein arms.

Combined analysis of nuclear and mitochondrial markers provide new insight into the genetic structure of North European Picea abies.

Norway spruce of northern Europe expanded at the end of the last glacial out of one refugium in Russia. To provide a detailed insight into how the genetic structure in the northern European lineage of this species has been shaped by postglacial migration, recurrent pollen flow and marginality, we here compare variation at seven highly variable nuclear microsatellite loci in 37 populations (1715 trees) with mitochondrial DNA variation. Microsatellite diversity was high (H(E)=0.640) and genetic differentiation was low (F(ST)=0.029). The microsatellite structure supported a mitochondrial DNA (mtDNA)-based hypothesis of two migration routes out of a single Russian refugium; one northwestern over Finland to northern Scandinavia, and one southwestern across the Baltic Sea into southern Scandinavia. Microsatellite diversity was maintained along the southwestern migration routes, whereas a significant decrease was observed towards the north. In contrast, the mtDNA diversity suggested higher amounts of historical gene flow towards the north than along the southwestern migration route. This suggests that the loss of nuclear diversity after postglacial colonization has been efficiently replenished by pollen-mediated gene flow in the south. Towards the north, smaller effective population size because of more limited seed and pollen production may have caused decreased nuclear diversity and increased inbreeding, reflecting the ecological marginality of the species in the north.

Coupled air/granular flow in a linear Hele-Shaw cell.

We investigate experimentally the pattern formation process during injection of air in a noncohesive granular material confined in a linear Hele-Shaw cell. We characterize the features and dynamics of this pattern formation on the basis of fast image analysis and sensitive pressure measurements. Behaviors are classified using two parameters--injection pressure and plate opening--and four hydrodynamic regimes are defined. For some regions of the parameter space, flows of air and grains are shown to be strongly coupled and instable, and lead to channelization within the granular material with obvious large-scale permeability variations.

Decompaction and fluidization of a saturated and confined granular medium by injection of a viscous liquid or gas.

We compare quantitatively two experimental situations concerning injection of a miscible fluid into an initially jammed granular medium saturated with the same fluid, confined in a Hele-Shaw cell. The two experiments are identical, apart from the interstitial and injected fluid, which is in one case air injected into a dry granular packing, and in the other case silicone oil injected into a dense suspension. In spite of the strong differences regarding the nature of the two fluids, strikingly similar dynamical and geometrical features are identified as functions of the control parameters: cell thickness and applied fluid injection pressure. In both cases an initial hydrodynamically driven decompaction process controls the unjamming and prepares the final displacement process characterized by fingerlike patterns empty of grains. The pattern shapes are comparable. In addition, the mobilities of the coupled fluid-grain flow, rescaled by the interstitial fluid viscosity and grain diameter squared, are of the same range and behave comparably. The mobility proves to depend on the initial solid fraction of the medium. Subtle differences are observed in geometrical aspects like the finger width with respect to the control parameters.

Pattern formation during air injection into granular materials confined in a circular Hele-Shaw cell.

We investigate the dynamics of granular materials confined in a radial Hele-Shaw cell, during central air injection. The behavior of this granular system, driven by its interstitial fluid, is studied both experimentally and numerically. This allows us to explore the associated pattern formation process, characterize its features and dynamics. We classify different hydrodynamic regimes as function of the injection pressure. The numerical model takes into account the interactions between the granular material and the interstitial fluid, as well as the solid-solid interactions between the grains and the confining plates. Numerical and experimental results are comparable, both to reproduce the hydrodynamical regimes experimentally observed, as well as the dynamical features associated to fingering and compacting.

Rapid and slow hydroxylators of seminal E prostaglandins.

Human seminal fluid contains prostaglandin (PG) E1, PGE2, 19-hydroxy-PGE1 and 19-hydroxy-PGE2 in large and variable amounts. 19-Hydroxy-PGE1 and 19-hydroxy-PGE2 are formed from PGE1 and PGE2 by prostaglandin 19-hydroxylase, a cytochrome P-450 enzyme, in seminal vesicles. The hypothesis that genetic polymorphism of this enzyme might contribute to the variable concentrations of PGE1, PGE2, 19-hydroxy-PGE1 and 19-hydroxy-PGE2 was examined by analysis of seminal fluid of 40 normal men. E prostaglandins were measured with 17-phenyl-PGE2 as an internal standard by high-performance liquid chromatography on beta-cyclodextrin silica. Using the ratios of substrate/product, i.e., R1 = PGE1/19-hydroxy-PGE1 and R2 = PGE2/19-hydroxy-PGE2, as indicators of prostaglandin 19-hydroxylase capacity, a bimodal distribution of R values was found: nine men (23%) were slow hydroxylators (R1 greater than 0.45 and R2 greater than 0.45), while the remaining men were rapid hydroxylators (both R1 and R2 less than 0.45). Semen of slow hydroxylators and semen of the five most rapid hydroxylators (both R1 and R2 less than 0.10) differed in absolute amounts of PGE1 and PGE2 but not in 19-hydroxy-PGE1 and 19-hydroxy-PGE2. 20-Hydroxy-PGE1 and 20-hydroxy-PGE2 are formed from PGE1 and PGE2 by cytochrome P-450 in the vesicular glands and the ampullae of deferent ducts of the ram. Seminal fluid of five rams was analyzed for PGE1, PGE2, 20-hydroxy-PGE1 and 20-hydroxy-PGE2, and a large variation in substrate/product ratios was found. Polymorphism of cytochrome P-450 might contribute to variations in seminal prostaglandins in man and in sheep.

The complete nucleotide sequence of the growth-hormone gene from Atlantic salmon (Salmo salar).

We report here the complete genomic nucleotide sequence for the Atlantic salmon growth-hormone gene (asGH), including 600 bp of 5' flanking sequences. The primary transcription (3651 nt) is significantly longer than that of the mammalian genes, mainly because of larger intron sizes, but also because the asGH gene contains an additional intron (intron 5). The coding regions of the asGH gene have been compared to the corresponding regions from rainbow trout (cDNA and genomic), coho salmon (cDNA) and chum salmon (cDNA). With the exception of the rainbow trout cDNA sequence, all results were in agreement with current classification of the four species. The results of a similar comparison with the mRNA leader and trailer regions were also consistent with current classification. Sequences upstream from the transcription start point have been compared to the corresponding regions from rainbow trout and mammalian GH gene (maGH) upstream sequences. The results showed that the upstream sequences in the two fish species were very similar, while short stretches similar to conserved upstream sequences in the maGH genes were also found. Some of these conserved sequences are known to be involved in the specificity of expression of the mammalian genes.

Evaluation of a commercially available kit for the colorimetric determination of zinc in human seminal plasma.

A kit from Wako Pure Chemical Industries for colorimetric determination of zinc has been evaluated for its possible use in the determination of zinc in human seminal plasma. The within-assay variation for 15 replicates of each of two seminal plasma samples having zinc concentrations (mM) of 0.43 +/- 0.025 and 6.06 +/- 0.125 (mean +/- SD) was 5.7% and 2.1%, respectively. The between-assay variation after analysis of 15 replicates of a seminal plasma sample (zinc conc. 5.6 mM) on different days was 2.3%. No interference from other metal ions present in seminal plasma was observed. The average % recovery of zinc added to seminal plasma was 102.7 +/- 1.77 (mean +/- SD). A close correlation (r = 0.996, n = 105) was found between the levels of zinc determined by the colorimetric method and that determined by atomic absorption spectrophotometry as reference method. It is concluded that the present colorimetric method, which is fast, sensitive and linear over the entire concentration range of zinc present in human seminal plasma, can be recommended for use in semen analysis laboratories.

Rupture of the lateral ligaments of the ankle: a controlled clinical trial.

The results of a randomized study comparing three different principles of treatment for rupture of the lateral ligaments of the ankle are presented. A total of 95 patients was treated and followed up for 17 months. In this series, 32 patients were treated with primary suture and plaster-of-Paris, 33 patients with plaster-of-Paris only and 30 patients with strapping. In all, 31 patients (97%) were completely free of symptoms in the operation group, 22 (67%) in the plaster-of-Paris group and 23 (77%) in the strapping group.

Influence of the female flowering environment on autumn frost-hardiness of Picea abies progenies.

Two experiments were designed to test possible effects of photoperiod and temperature during microsporogensis to anthesis on early autumn frost-hardiness of Picea abies progenies. Pollen lots were produced in phytotron rooms and used in crosses in a seed orchard. No biologically important differences in progeny performance were evident either between high and low temperature or between long and short-day treatments, and no significant interaction between photoperiod and temperature was found. In a third experiment, however, an effect of the environment during female flowering was obtained. Crosses performed in early spring (March) inside a heated greenhouse (short day, high temperature) produced progenies which were less hardy than their full-sibs reproduced from crosses indoors (long day, high temperature) and outdoors (long day, low temperature) in May. The most hardy siblings originated from the late-spring outdoor crosses. These results indicate that some stages in reproduction during female flowering, such as female meiosis, pollen tube growth, syngamy, early embryogenesis and embryo competition, may be sensitive to temperature and/or photoperiodic signals which can be transmitted to the progeny. We suspect that the altered performance of the progenies could be due to an activation of a regulatory mechanism affecting the expression of genes controlling adaptive traits. Both the present and earlier results have implications for the genetic interpretation of provenance differences in Norway spruce.

Interaction of the CNC-bZIP factor TCF11/LCR-F1/Nrf1 with MafG: binding-site selection and regulation of transcription.

We have previously shown that the widely expressed human transcription factor TCF11/LCR-F1/Nrf1 interacts with small Maf proteins and binds to a subclass of AP1-sites. Such sites are required for beta-globin 5' DNase I hypersensitive site 2 enhancer activity, erythroid porphobilinogen deaminase inducibility, hemin responsiveness by heme-oxygenase 1 and expression of the gene NAD(P)H:quinone oxidoreductase1. Here we report the optimal DNA-binding sequences for TCF11/LCR-F1/Nrf1 alone and as a heterodimer with MafG, identified by using binding-site selection. The heterodimer recognises a 5'-TGCTgaGTCAT-3' binding-site that is identical to the established NF-E2-site, the antioxidant response element and the heme-responsive element while the binding specificity of the homomer is less stringent. To investigate the activity of TCF11 through this selected site, both alone and in the presence of MafG, we have used a transient transfection assay. TCF11 alone activates transcription while MafG alone acts as a repressor. When co-expressed, MafG interferes with TCF11 transactivation in a dose dependent manner. This indicates that MafG protein, which heterodimerises efficiently with TCF11 in vitro (the heterodimer having a higher affinity for DNA than TCF11 alone), does not co-operate with TCF11 in transactivating transcription. We propose that since both these factors are widely expressed, they may act together to contribute to the negative regulation of this specific target site. Efficient positive regulation by TCF11 may require alternative partners with perhaps more restricted expression patterns.

Small Maf proteins interact with the human transcription factor TCF11/Nrf1/LCR-F1.

The human TCF11 gene encodes a ubiquitously expressed bZIP transcription factor of the cap n' collar (CNC) domain family. It has a high sequence similarity to the erythroid-specific bZIP factor p45 NF-E2 in the CNC domain, which is involved in DNA binding. LCR-F1, a TCF11 isoform, is a more potent transcriptional activator than p45 NF-E2 in erythroid cells. We show here that the TCF11 protein interacts to form heterodimers with small Maf proteins, previously shown to dimerize with p45 NF-E2, ECH and Fos. Such heterodimerization significantly alters the DNA binding characteristics of TCF11. While TCF11 alone binds in vitro to the tandem NF-E2 site derived from 5' DNase hypersensitive site 2 in the beta-globin locus control region and to the single NF-E2 site in the porphobilinogen deaminase gene promoter, stronger binding is detected in the presence of small Maf proteins. Using antibodies, TCF11 isoforms bound to the single NF-E2 site were detected in K562 erythroid cell nuclear extracts. These findings place TCF11 as a good candidate for the proposed widely expressed factor(s) known to interact with small Maf proteins and bind NF-E2 sites in a sequence-specific manner resembling NF-E2.

Structural organization and mapping of the human TCF11 gene.

We recently cloned human cDNA representing several mRNA isoforms of human TCF11, a transcription factor of the basic-region, leucine-zipper (bZIP) family located on chromosome 17q22 as well as a genomic clone of this gene. We have now determined the complete genomic organization of the TCF11 gene, which consists of 9 exons distributed over 15 kb of genomic DNA. Pulsed-field gel electrophoresis was used to construct a physical map around TCF11, to characterize a 450-kb YAC clone that contains the gene, and to link TCF11 physically to BTR, a marker on chromosome 17.

Molecular cloning of a putative novel human bZIP transcription factor on chromosome 17q22.

We have cloned and characterized cDNA clones representing several mRNA isoforms generated by alternative splicing of a single gene localized to chromosome 17q22. Sequence analysis showed that the predicted translational product of the longest open reading frame (2316 nucleotides, 772 amino acids) is related to transcription factors of the basic leucine zipper (bZIP) class. The sequence contained several regions characteristic of transcriptional regulatory domains. A cluster of amino acids flanking the bZIP region on both sides was highly conserved between TCF11 and p45 NF-E2, a subunit of the human globin locus control region-binding protein, NF-E2. These same regions showed remarkable homology to two invertebrate proteins, CNC and skin-1, postulated to regulate embryonic development in Drosophila melanogaster and Caenorhabditis elegans, respectively.