Genetic evidence that SMAD2 is not required for gonadal tumor development in inhibin-deficient mice

<p>Abstract</p> <p>Background</p> <p>Inhibin is a tumor-suppressor and activin antagonist. Inhibin-deficient mice develop gonadal tumors and a cachexia wasting syndrome due to enhanced activin signaling. Because activins signal through SMAD2 and SMAD3 in vitro and loss of SMAD3 attenuates ovarian tumor development in inhibin-deficient females, we sought to determine the role of SMAD2 in the development of ovarian tumors originating from the granulosa cell lineage.</p> <p>Methods</p> <p>Using an inhibin α null mouse model and a conditional knockout strategy, double conditional knockout mice of Smad2 and inhibin alpha were generated in the current study. The survival rate and development of gonadal tumors and the accompanying cachexia wasting syndrome were monitored.</p> <p>Results</p> <p>Nearly identical to the controls, the Smad2 and inhibin alpha double knockout mice succumbed to weight loss, aggressive tumor progression, and death. Furthermore, elevated activin levels and activin-induced pathologies in the liver and stomach characteristic of inhibin deficiency were also observed in these mice. Our results indicate that SMAD2 ablation does not protect inhibin-deficient females from the development of ovarian tumors or the cachexia wasting syndrome.</p> <p>Conclusions</p> <p>SMAD2 is not required for mediating tumorigenic signals of activin in ovarian tumor development caused by loss of inhibin.</p

Calculating real roots using Chebyshev polynomials

V diplomskem delu bomo predstavili Čebiševe polinome prve in druge vrste, njihove lastnosti ter Čebiševo vrsto. Uporabili bomo Čebiševe polinome prve vrste za iskanje ničel gladke funkcije f na danem intervalu. Najprej bomo funkcijo aproksimirali z Čebiševimi polinomi in nato nad končno Čebiševo vrsto uporabili polinomske iskalnike ničel. V nadaljevanju pa bomo predstavili, kako najti ničle polinomske funkcije na nekem intervalu, ki ga bomo pri nekaterih algoritmih razdelili na podintervale z namenom natančnejšega in tudi hitrejšega iskanja ničel. Predstavljenih bo nekaj algoritmov in njihova uporaba, pa tudi njihove zahtevnosti, slabosti in omejitve. V okviru dela smo algoritme tudi sprogramirali v programu Matlab. Njihova praktična uporaba bo predstavljena na primerih.In this work, Chebyshev polynomials of the first and the second kind, their properties and the Chebyshev series will be examined. We will use Chebyshev polynomials of the first kind to find roots of the smooth function f on the given interval. At first the function will be approximated and then the polynomial root-finders on the truncated Chebyshev series will be used. In the next chapter we will study how to find roots of a polynomial function on the interval which we will, with some algorithms, divide on subintervals with the purpose of more accurate and faster finding of the roots. Different algorithms and their use, their complexity and their strengths and weaknesses will be presented. During this work we have also programmed these algorithms in Matlab. We will show their practical application on some examples

Correction to: Identification of novel Y chromosome encoded transcripts by testis transcriptome analysis of mice with deletions of the Y chromosome long arm.

Following publication of the original article [1], the following error was reported: The actin control panel in Fig. 3 of this paper is reproduced from Fig. 7 of Touré et al, 2004 [2] by kind permission of the Genetics Society of America. Touré et al, 2004 used Northern blotting to show that the Y-linked genes Ssty1 and Ssty2 have reduced expression in a range of mouse genotypes with deletions on the Y chromosome long arm. This paper shows that two novel genes, Sly and Asty are also present on mouse Yq and have reduced expression in these deleted genotypes. A further companion paper was published in Human Molecular Genetics (Ellis et al, 2005 [3]) showing that X-linked genes are upregulated in the various deleted genotypes. Since two of the genotypes concerned are sterile and very hard to generate, all the Northern blot experiments in these papers were performed on a single membrane that was stripped and re-probed with a range of different X- and Y-linked genes. The same beta-actin loading control image thus necessarily applies to all the data presented, and was shown in all three papers. We regret that this was not mentioned appropriately in the Methods and figure legends at the time of publication

Specific interaction with the nuclear transporter importin α2 can modulate paraspeckle protein 1 delivery to nuclear paraspeckles

Importin (IMP) superfamily members mediate regulated nucleocytoplasmic transport, which is central to key cellular processes. Although individual IMPα proteins exhibit dynamic synthesis and subcellular localization during cellular differentiation, including during spermatogenesis, little is known of how this affects cell fate. To investigate how IMPαs control cellular development, we conducted a yeast two-hybrid screen for IMPα2 cargoes in embryonic day 12.5 mouse testis, a site of peak IMPα2 expression coincident with germ-line masculization. We identified paraspeckle protein 1 (PSPC1), the original defining component of nuclear paraspeckles, as an IMPα2-binding partner. PSPC1-IMPα2 binding in testis was confirmed in immunoprecipitations and pull downs, and an enzyme-linked immunosorbent assay–based assay demonstrated direct, high-affinity PSPC1 binding to either IMPα2/IMPβ1 or IMPα6/IMPβ1. Coexpression of full-length PSPC1 and IMPα2 in HeLa cells yielded increased PSPC1 localization in nuclear paraspeckles. High-throughput image analysis of >3500 cells indicated IMPα2 levels can directly determine PSPC1-positive nuclear speckle numbers and size; a transport-deficient IMPα2 isoform or small interfering RNA knockdown of IMPα2 each reduced endogenous PSPC1 accumulation in speckles. This first validation of an IMPα2 nuclear import cargo in fetal testis provides novel evidence that PSPC1 delivery to paraspeckles, and consequently paraspeckle function, may be controlled by modulated synthesis of specific IMPs

Identification of novel Y chromosome encoded transcripts by testis transcriptome analysis of mice with deletions of the Y chromosome long arm.

BACKGROUND: The male-specific region of the mouse Y chromosome long arm (MSYq) is comprised largely of repeated DNA, including multiple copies of the spermatid-expressed Ssty gene family. Large deletions of MSYq are associated with sperm head defects for which Ssty deficiency has been presumed to be responsible. RESULTS: In a search for further candidate genes associated with these defects we analyzed changes in the testis transcriptome resulting from MSYq deletions, using testis cDNA microarrays. This approach, aided by accumulating mouse MSYq sequence information, identified transcripts derived from two further spermatid-expressed multicopy MSYq gene families; like Ssty, each of these new MSYq gene families has multicopy relatives on the X chromosome. The Sly family encodes a protein with homology to the chromatin-associated proteins XLR and XMR that are encoded by the X chromosomal relatives. The second MSYq gene family was identified because the transcripts hybridized to a microarrayed X chromosome-encoded testis cDNA. The X loci ('Astx') encoding this cDNA had 92-94% sequence identity to over 100 putative Y loci ('Asty') across exons and introns; only low level Asty transcription was detected. More strongly transcribed recombinant loci were identified that included Asty exons 2-4 preceded by Ssty1 exons 1, 2 and part of exon 3. Transcription from the Ssty1 promotor generated spermatid-specific transcripts that, in addition to the variable inclusion of Ssty1 and Asty exons, included additional exons because of the serendipitous presence of splice sites further downstream. CONCLUSION: We identified further MSYq-encoded transcripts expressed in spermatids and deriving from multicopy Y genes, deficiency of which may underlie the defects in sperm development associated with MSYq deletions.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

The Tetraspanin Protein CD37 Regulates IgA Responses and Anti-Fungal Immunity

Immunoglobulin A (IgA) secretion by plasma cells in the immune system is critical for protecting the host from environmental and microbial infections. However, the molecular mechanisms underlying the generation of IgA+ plasma cells remain poorly understood. Here, we report that the B cell–expressed tetraspanin CD37 inhibits IgA immune responses in vivo. CD37-deficient (CD37−/−) mice exhibit a 15-fold increased level of IgA in serum and significantly elevated numbers of IgA+ plasma cells in spleen, mucosal-associated lymphoid tissue, as well as bone marrow. Analyses of bone marrow chimeric mice revealed that CD37–deficiency on B cells was directly responsible for the increased IgA production. We identified high local interleukin-6 (IL-6) production in germinal centers of CD37−/− mice after immunization. Notably, neutralizing IL-6 in vivo reversed the increased IgA response in CD37−/− mice. To demonstrate the importance of CD37—which can associate with the pattern-recognition receptor dectin-1—in immunity to infection, CD37−/− mice were exposed to Candida albicans. We report that CD37−/− mice are evidently better protected from infection than wild-type (WT) mice, which was accompanied by increased IL-6 levels and C. albicans–specific IgA antibodies. Importantly, adoptive transfer of CD37−/− serum mediated protection in WT mice and the underlying mechanism involved direct neutralization of fungal cells by IgA. Taken together, tetraspanin protein CD37 inhibits IgA responses and regulates the anti-fungal immune response

Standards in semen examination:publishing reproducible and reliable data based on high-quality methodology

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.Peer reviewe

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead