169,847 research outputs found
The putative peroxisomal gene Pxt1 is exclusively expressed in the testis
No full textGenes reported to be crucial for spermatogenesis are often exclusively expressed in the testis. We have identified a novel male germ cell-specific expressed gene named peroxisomal testis specific 1 (Pxt1) with expression starting at the spermatocyte stage during mouse spermatogenesis. The putative amino acid sequence encoded by the cDNA of the Pxt1 gene contains a conserved Asn-His-Leu (NHL)-motif at its C-terminal end, which is characteristic for peroxisomal proteins. Pxt1-EGFP fusion protein is co-localized with known peroxisomal marker proteins in transfected NIH3T3 cells. In addition, we could demonstrate that the peroxisomal targeting signal NHL is functional and responsible for the correct subcellular localization of the Pxt1-EGFP fusion protein. In male germ cells peroxisomes were reported only in spermatogonia. The Pxt1 gene is so far the first gene coding for a putative peroxisomal protein which is expressed in later steps of spermatogenesis, namely in pachytene spermatocytes. Copyright (C) 2007 S. Karger AG, Basel
Bericht über das Forschungs- und Praxiskolloquium am 21. Mai 2016 im Rahmen der Frühjahrstagung des AK Methoden der DeGEval
No full textPierobon C, Mäder S, Burfeind M, Gehre A, Ulrich A. Bericht über das Forschungs- und Praxiskolloquium am 21. Mai 2016 im Rahmen der Frühjahrstagung des AK Methoden der DeGEval. Zeitschrift für Evaluation. 2016;2:266-270
Isolation and characterization of a novel human gene, NIF3L1,and its mouse ortholog, Nif3/1, highly conserved from bacteria to mammals
No full textWe report the cloning and characterization of novel human and murine genes NIF3L1 and Nif3l1 which are strongly homologous to the yeast Ngg1-interacting factor 3 homolog. Mouse Nif3l1 and human NIF3L1 encode predicted proteins of 376 amino acids and 377 amino acids, respectively. Northern blot analysis on RNA from different postnatal murine tissues showed a ubiquitous expression pattern of mouse Nif3l1 with a transcript of approximately 1.85 kb. RT-PCR analysis on prenatal mouse RNA and embryonic stem cell RNA demonstrated expression of Nif3l1 throughout embryonic development. Additionally, expression analysis on cell lines revealed strong overexpression of Nif3l1 in the spermatogonia-derived cell line GC-1 spg and in the teratocarcinoma cell line F9. The mouse gene was mapped to chromosome 1, region C. Human NIF3L1 consists of seven exons spanning 14.5 kb of genomic DNA and is located on chromosome 2q33. A fusion protein consisting of the GFP (green fluorescent protein) and the ORF of human NIF3L1 showed a localization of the predicted protein in the cytoplasm. In the N-terminal and C-terminal region, mouse Nif3l1 and human NIF3L1 are strongly homologous to proteins of other species, e.g. the recently cloned Drosophila symbol=anon-35F/36F gene with 41 %, amino acid identity and several proteins from yeast including the yeast Ngg1-interacting factor 3 homolog with 46 % amino acid identity, the hypothetical protein YGL221c and yeast Ngg1-interacting factor 3 (Nif3) with 37 % amino acid identity. Other proteins from lower organisms, e.g a conserved hypothetical protein from Ureaplasma urealyticum or a hypothetical protein SCC30.09c from Streptomyces coelicolor show approximately 25-30 % amino acid identity in the two flanking regions of the protein. These similarities indicate a high degree of conservation of mouse Nif3l1 and human NIF3L1 from bacteria to mammals. Copyright (C) 2000 S. Karger AG, Basel
Male mice lacking the theg (Testicular haploid expressed gene) protein undergo normal spermatogenesis and are fertile
No full textThe testicular haploid expressed gene (Theg) encodes for a novel similar to42.0-kDa nuclear protein, which is specifically expressed in spermatid cells. Its expression is upregulated by some unknown factor(s) from Sertoli cells. To elucidate the function of Theg protein and its role in spermatogenesis, we disrupted the Theg locus in mouse by homologous recombination. For functional dissection of the domain structure of the Theg protein, two different knockout approaches were undertaken. In the first knockout mouse (Th14), the C-terminal region of the Theg protein (amino acids 137-376) was deleted. Both Th14(+/-) and Th14(-/-) mice from genetic backgrounds of C57BL/6J X 129X1/ SvJ hybrid and 129X1/SvJ inbred exhibited a normal phenotype and were fertile. The testes of Th14(-/-) mice were smaller than those of Th14(+/-) and Th14(+/+) mice; however, the testicular morphology and the properties of sperm, including morphology and motility, from Th14(-/-) mice were similar to those of Th14(+/-) and Th14(+/+) mice. These results demonstrate that the C-terminal region of Theg (amino acids 137-376) does not play an important role in progression of spermatogenesis. In the second knockout mouse (Th15), we deleted the N-terminal domain of the Theg protein, which resulted in complete loss of Theg transcripts. Both Th15(+/-) and Th15(-/-) mice from genetic backgrounds C57BL/6J x 129X1/SvJ hybrid, C3H/J congenic, and 129X1/SvJ inbred appeared normal and were fertile, with no gross abnormalities detected in testicular morphology or sperm properties. Our results from both knockout mouse model systems clearly illustrate that Theg is not essential for spermatogenesis in the mouse
PHYSIOLOGICAL FUNCTIONS OF THE HUMAN FINGER
No full textUsing morphological data describing the physiological Curvature morphology of the corresponding articulating surfaces in each finger joint, it is shown that a) the flexion of each finger joint is described by two angles of flexion; b) in each finger joint, a "pump mechanism" for synovial fluid is present whose function is to lubricate and nourish the joint cartilage and c) finger posture has six kinematic degrees of freedom (DOF). Since six muscle forces control Finger posture, the relationship between the muscle forces and finger posture is unambiguously described. The states of flexion of the interphalangeal joints restrict possible flexions in the metacarpophalangeal joint. Since the muscle forces act Simultaneously on all three finger joints, the interdependence of the flexional states in the three finger joints can be attributed to the alignment of the lines of force and their sites of insertion, as a function of the corresponding flexion in the joints
Identification and characterization of a novel murine multigene family containing a PHD-finger-like motif
No full textThe genes Phf5a and Phf5b-ps are the First two members of a novel murine multigene family that is highly conserved during evolution and belongs to the superfamily of PHD-finger genes. The Phf5 gene family contains an active locus on mouse chromosome 15. region E and several processed pseudogenes on different chromosomes. The active locus, Phf5a, is expressed ubiquitously in pre- and postnatal murine tissues and encodes a protein of 110 amino acids. The protein is localized in the nucleus in a non-homogenous pattern as the nucleolar subcompartment is almost free of Phf5a. The molecular and biological functions of Phf5a are unknown up-to-date. but the systematic deletion of its yeast homolog is lethal, pointing out that the protein is required for cell viability. Interpretation of our data and review of the literature suggest both basic and essential cellular functions of the Phf5a protein, possibly acting as a chromatin-associated protein. (C) 2002 Elsevier Science (USA). All rights reserved
PHYSIOLOGICAL FUNCTIONS OF THE HUMAN FINGER
No full textUsing morphological data describing the physiological Curvature morphology of the corresponding articulating surfaces in each finger joint, it is shown that a) the flexion of each finger joint is described by two angles of flexion; b) in each finger joint, a "pump mechanism" for synovial fluid is present whose function is to lubricate and nourish the joint cartilage and c) finger posture has six kinematic degrees of freedom (DOF). Since six muscle forces control Finger posture, the relationship between the muscle forces and finger posture is unambiguously described. The states of flexion of the interphalangeal joints restrict possible flexions in the metacarpophalangeal joint. Since the muscle forces act Simultaneously on all three finger joints, the interdependence of the flexional states in the three finger joints can be attributed to the alignment of the lines of force and their sites of insertion, as a function of the corresponding flexion in the joints
Factor XII deficiency is strongly associated with primary recurrent abortions
No full textObjective: To evaluate factor XII deficiency in women with primary and secondary recurrent abortion. Design: Prospective case-control study. Setting: University hospital. Patient(s): Sixty-seven women with primary and 33 women with secondary recurrent abortion of unexplained nature and 49 healthy controls with no history of thrombotic disease or adverse pregnancy outcomes. Main Outcome Measure(s): Plasma factor XII activity, activated protein C resistance, factor V Leiden mutation analysis, protein C, protein S, antithrombin III, karyotyping, and anticardiolipin antibodies. Result(s): Ten of 67 women with primary recurrent abortion (14.9%) and 4 of 33 women (12.1%) with secondary recurrent abortion had reduced factor XII activity (<60%). These results are highly significant in the former group and showed a tendency toward significance in the latter group. All controls had normal factor XII activity. Conclusion(s): Factor XII deficiency is strongly associated with primary recurrent abortion, and women with secondary recurrent abortion show a tendency toward factor XII deficiency. (C) 2003 by American Society for Reproductive Medicine
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
PHF5A represents a bridge protein between splicing proteins and ATP-dependent helicases and is differentially expressed during mouse spermatogenesis
No full textPHF5A is a highly conserved protein from yeast to man, and based on studies in yeast, it was suggested that the homologous protein RDS3P in S. cerevisiae takes part in the organization of U2 snRNP particles. By using the yeast two-hybrid assay we could demonstrate that PHF5A interacted both with ATP-dependent helicases EP400 and DDX1 and with arginine-serine (RS)-rich domains of splicing factors U2AF1 and SFRS5 in mouse. Furthermore, domain interaction studies revealed that PHF5A interaction with EP400 and DDX1 is restricted to the N-terminal part of PHF5A, whereas the C-terminal region of PHF5A was found to be responsible for the association with U2AF1 and SFRS5. By using the yeast three-hybrid assay, we could further show that both EP400 and DDX1 interacted only indirectly with U2AF1 and SFRS5 proteins via the bridge protein PHF5A. The subcellular localization of a PHF5A-GFP fusion protein was predominantly observed in the nucleus and, in addition, PHF5A co-localized with both U2AF1 and SFRS5 proteins in nuclear speckles of NIH3T3 cells. Moreover, expression analyses demonstrated that PHF5A and U2AF1 gene expression coincided in spermatocytes during murine spermatogenesis and interaction between these proteins was also detectable in the spermatocyte-specific cell line GC-4spc by using in vivo co-immunoprecipitation studies. Taken together, our results indicate that PHF5A resembles a protein which interacts with splicing factors U2AF1 and SFRS5 and helicases EP400 and DDX1 and functions as a bridge protein between these proteins. Copyright (c) 2008 S. Karger AG, Basel.Deutsche Forschungsgemeinschaft [SFB 271
- …
