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NSAIDs are commonly used among athletes for a variety of reasons. The purpose of this research is to gain insight on Division III athletes 'view and opinions of NSAIDs. A survey was developed incorporating the Theory of Planned Behavior and distributed to all winter and spring athletic teams of one Midwestern Dill University. By utilizing the Theory of Planned Behavior, this study found attitude toward behavior as the strongest predictor of behavioral intention (p < .001), while both Perceived Behavioral control (p < .001) and Intention (p < .001) were statistically significant predictors of behavior. Another finding from the study was that athletes perceived less than 25% of their teammates as taking NSAIDs. Displaying the importance of an athlete's own persona! values and opinions of NSAID use was the strongest predictor of intentions. Further assessment should include more athletes to get a better representation of the athletic department., Nonsteroidal anti-inflammatory drugs (NSAIDs) are among one of the most commonly purchased over the counter (OTC) medications. NSAIDs are used for a variety of reasons including: treatment of pain, soft [...]

ABSTRACT This study assessed the Integrated Behavioral Model's (IBM) utility in explaining high-risk drinking among college students. A total of 356 participants completed a four-page questionnaire based on the (IBM) [...]

Stem cells support tissue maintenance by balancing self-renewal and differentiation. In mice, it is believed that a homogeneous stem cell population of single spermatogonia supports spermatogenesis, and that differentiation, which is accompanied by the formation of connected cells (cysts) of increasing length, is linear and nonreversible. We evaluated this model with the use of lineage analysis and live imaging, and found that this putative stem cell population is not homogeneous. Instead, the stem cell pool that supports steady-state spermatogenesis is contained within a subpopulation of single spermatogonia. We also found that cysts are not committed to differentiation and appear to recover stem cell potential by fragmentation, and that the fate of individual spermatogonial populations was markedly altered during regeneration after damage. Thus, there are multiple and reversible paths from stem cells to differentiation, and these may also occur in other systems. 10.1126/science.1182868

Author(s): Mary E. Dickinson; Ann M. Flenniken; Xiao Ji; Lydia Teboul; Michael D. Wong; Jacqueline K. White; Terrence F. Meehan; Wolfgang J. Weninger; Henrik Westerberg; Hibret Adissu; Candice N. Baker; [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2007.01.005 Byline: Ming Zhao (a), Jan Rohozinski (b), Manju Sharma (c), Jun Ju (a), Robert E. Braun (c), Colin E. Bishop (b)(d), Marvin L. Meistrich (a) Keywords: Spermatogenesis; Retroposons; Retrotransposition; Utp14; Juvenile spermatogonial depletion; X-chromosome; Spermatocytes; Spermatogonia; Male germ cells Abstract: The mouse retrogene Utp14b is essential for male fertility, and a mutation in its sequence results in the sterile juvenile spermatogonial depletion (jsd) phenotype. It is a retrotransposed copy of the Utp14a gene, which is located on the X chromosome, and is inserted within an intron of the autosomal acyl-CoA synthetase long-chain family member 3 (Acsl3) gene. To elucidate the roles of the Utp14 genes in normal spermatogenic cell development as a basis for understanding the defects that result in the jsd phenotype, we analyzed the various mRNAs produced from the Utp14b retrogene and their expression in different cell types. Two classes of transcripts were identified: variant 1, a transcript driven by the host gene promoter, that is predominantly found in germ cells but is ubiquitously expressed at low levels; and variants 2-5, a group of alternatively spliced transcripts containing some unique untranslated exons that are transcribed from a novel promoter that is germ-cell-specific. Utp14b (predominantly variant 1) is expressed at moderately high levels in pachytene spermatocytes, the developmental stage at which the expression of the X-linked Utp14a is suppressed. The levels of both classes of Utp14b transcripts were highest in round spermatids despite the transcription of Utp14a in these cells. We propose that when Utp14b initially inserted into Acsl3, it utilized the Acsl3 promoter to drive expression in pachytene spermatocytes to compensate for inactivation of Utp14a expression. The novel cell-type-specific promoter for Utp14b likely evolved later, as the protein may have acquired a germ cell-specific function in spermatid development. Author Affiliation: (a) Department of Experimental Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Box 066, 1515 Holcombe Blvd, Houston, TX 77030, USA (b) Department of Obstetrics and Gynecology, Baylor College of Medicine, 1709 Dryden Road, Houston, TX 77030, USA (c) Department of Genome Sciences, University of Washington School of Medicine, Box 357730, 1705 N.E. Pacific Street, Seattle, WA 98195, USA (d) Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Article History: Received 28 September 2006; Revised 9 December 2006; Accepted 3 January 2007

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cell.2006.11.016 Byline: Geraldine Seydoux (1), Robert E. Braun (2) Abstract: Oocytes and sperm are some of the most differentiated cells in our bodies, yet they generate all cell types after fertilization. Accumulating evidence suggests that this extraordinary potential is conferred to germ cells from the time of their formation during embryogenesis. In this Review, we describe common themes emerging from the study of germ cells in vertebrates and invertebrates. Transcriptional repression, chromatin remodeling, and an emphasis on posttranscriptional gene regulation preserve the totipotent genome of germ cells through generations. Author Affiliation: (1) Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA (2) Department of Genome Sciences, University of Washington School of Medicine, 1705 N.E. Pacific Street, Seattle, WA 98195, USA

The characteristics that distinguish germ cells from somatic cells and speculate on the mechanisms that allow germ cells to develop, proliferate, and differentiate while avoiding the loss of totipotency that befalls somatic cells is discussed. The remarkable plasticity and regenerative abilities of germ cells suggests that germ cells maintain a totipotent genome through most of development.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.02.013 Byline: Christopher Payne, Robert E. Braun Keywords: Histone modification; Germ cells; Spermatogonia; Epigenetics; Stem cells; Transcriptional repression Abstract: Chromatin structure plays an important role in the regulation of gene expression. Methylation of lysine residues on histone tails is an epigenetic mark that influences chromatin repression when specifically imparted on lysines 9 and 27 of histone H3, and on lysine 20 of H4. Histone lysines can be mono-, di-, and trimethylated, and all three modification states have been identified in different nuclear domains. Correlation of these methylated histone states to different stages of cell differentiation, however, is not extensive. Mammalian spermatogenesis is a developmental process ideal for studying the epigenetic control of differentiation. Maintenance of spermatogonial stem cells requires the transcriptional repressor Plzf, but a role for histone methylation has not been established. Here we show that Plzf-expressing spermatogonia completely lack monomethyl-H3-K27 and monomethyl-H4-K20, and contain very little monomethyl-H3-K9. Dimethylated H3-K27 and H4-K20 are detected as punctate foci in Plzf-positive cells, but dimethyl-H3-K9 is absent. Trimethylated H3-K9 and H4-K20 exhibit a unique perinuclear distribution that coincides with Plzf expression, localizing to punctate foci in more differentiated spermatogonia. Loss of Plzf correlates with increased punctate distribution of trimethylated H3-K9 and H4-K20 at the expense of perinuclear localization. These data signify the possible importance of different histone lysine methylation states in the epigenetic control of spermatogenesis. Author Affiliation: Department of Genome Sciences, University of Washington School of Medicine, Box 357730, 1705 N.E. Pacific Street, Seattle, WA 98195, USA Article History: Received 22 September 2005; Revised 26 January 2006; Accepted 13 February 2006

Discrete perinuclear dispersion feature of histone lysine trimethylation in Plzf-expressing spermatogonia is studied.

Cytokinesis in somatic cells concludes with the formation of a midbody0 which is abscised to form individual daughter cells. In contrast, germ cell cytokinesis results in a permanent intercellular bridge connecting the daughter cells through a large cytoplasmic channel. During spermatogenesis, proposed roles for the intercellular bridge include germ cell communication, synchronization, and chromosome dosage compensation in haploid cells. Although several essential components of the midbody have recently been identified, essential components of the vertebrate germ cell intercellular bridge have until now not been described. Herein, we show that testis-expressed gene 14 (TEX14) is a novel protein that localizes to germ cell intercellular bridges. In the absence of TEX14, intercellular bridges are not observed by using electron microscopy and other markers. Spermatogenesis in [Tex14.sup.-I-] mice progresses through the transit amplification of diploid spermatogonia and the expression of early meiotic markers but halts before the completion of the first meiotic division. Thus, TEX14 is required for intercellular bridges in vertebrate germ cells, and these studies provide evidence that the intercellular bridge is essential for spermatogenesis and fertility. cytoplasmic bridges | knockout mouse | male infertility | male sterility | ring canals

Within the mammalian testis, specialized tight junctions between somatic Sertoli cells create basal and apical polarity within the cells, restrict movement of molecules between cells, and separate the seminiferous epithelium into basal and adluminal compartments. These tight junctions form the basis of the blood--testis barrier, a structure whose function and dynamic regulation is poorly understood. In this study, we used microarray gene expression profiling to identify genes with altered transcript levels in a mouse model for conditional androgen insensitivity. We show that testosterone, acting through its receptor expressed in Sertoli cells, regulates the expression of claudin 3, which encodes a transient component of newly formed tight junctions. Sertoli cell-specific ablation of androgen receptor results in increased permeability of the blood--testis barrier to biotin, suggesting claudin 3 regulates the movement of small molecules across the Sertoli cell tight junctions. These results suggest that androgen action in Sertoli cells regulates germ cell differentiation, in part by controlling the microenvironment of the seminiferous epithelium. Our studies also indicate that hormonal strategies for male contraception may interfere with the blood--testis barrier. androgen receptor | testosterone | tight junctions

Gametes rely heavily on posttranscriptional control for their differentiation. Translational control, alternative splicing, and alternative processing of the 3' end of mRNAs are all common during spermatogenesis. Tent, which encodes a highly conserved 72-kDa protein, is expressed solely in germ ceils of the testis from the mid-pachytene stage until the elongating spennatid stage. TENR contains a double-stranded RNA binding domain, is localized to the nucleus, and is phylogenetically related to a family of adenosine deaminases involved in RNA editing. We show here that targeted mutation of the Tenr gene causes male sterility. Tenr mutant males have a reduced sperm count, and [Ten.sup.-/-] sperm show a decrease in motility and an increase in malformed heads. Despite their sterility, some epididymal sperm from Tenr mutants have normal morphology. The ability of Tenr mutant sperm to fertilize zona pellucida-free oocytes and to bind to, but not fertilize, zona pellucida-intact oocytes suggests that the normal-appearing sperm are not able to penetrate the zona pellucida. These data suggest that TENR plays an essential function in spermatid morphogenesis. Kerywords: Spermatogenesis; Posttranscriptional control; RNA editing

Approximately one-third of all mammalian genes are essential for life. Phenotypes resulting from knockouts of these genes in mice have provided tremendous insight into gene function and congenital disorders. As part of the International Mouse Phenotyping Consortium effort to generate and phenotypically characterize 5,000 knockout mouse lines, here we identify 410 lethal genes during the production of the first 1,751 unique gene knockouts. Using a standardized phenotyping platform that incorporates high-resolution 3D imaging, we identify phenotypes at multiple time points for previously uncharacterized genes and additional phenotypes for genes with previously reported mutant phenotypes. Unexpectedly, our analysis reveals that incomplete penetrance and variable expressivity are common even on a defined genetic background. In addition, we show that human disease genes are enriched for essential genes, thus providing a dataset that facilitates the prioritization and validation of mutations identified in clinical sequencing efforts., Author(s): Mary E. Dickinson [1]; Ann M. Flenniken [2, 3]; Xiao Ji [4]; Lydia Teboul [5]; Michael D. Wong [2, 6]; Jacqueline K. White [7]; Terrence F. Meehan [8]; Wolfgang [...]

The mouse protamine mRNAs, Prm-1 and Prm-2, are translationally repressed for several days during male germ cell differentiation. The translational delay of mouse Prm-1 mRNA has previously been shown to be dependent upon cis-acting elements that reside in the last 62 nucleotides of the Prm-1 3[prime] untranslated region (3[prime] UTR). We have previously identified a 48/50-kDa protein that binds the 3[prime] UTRs of both Prm-1 and Prm-2 mRNAs in a sequence-specific manner, is present in cytoplasmic fractions of postmeiotic round spermatids where the protamine mRNAs are translationally silent, and is markedly reduced in elongated spermatids where the protamine mRNAs become activated for translation. Surprisingly, the binding site for this activity maps to a region of the Prm-1 3[prime] UTR not contained within the functional 62 nucleotides described above. In this report we show that the binding site for the 48/50-kDa protein can also delay translation of a reporter RNA in vivo, suggesting that the 48/50-kDa protein can repress the translation of Prm-1 mRNA during murine spermatogenesis. This observation proves that two separate regions of the Prm-1 3[prime] UTR are sufficient to repress Prm-1 translation. In addition, immunocytochemistry and polysome analysis have revealed that this transgenic reporter mRNA fails to undergo proper translational activation. These results suggest that an additional region of the Prm-1 3[prime] UTR is required for proper translational activation and that Prm-1 translational repression elements can be separated from those involved in translational activation.

A study was conducted to determine whether the temporal expression of the testis nuclear basic proteins is necessary for normal spermatid differentiation. Transgenic mice that fail to delay protamine 1 (Prm1) mRNA translation displayed abnormal condensation of the nuclear DNA. There was also a high degree of male sterility in the mice due to the incomplete spermatid differentiation.

The localization of Spnr proteins in the testis of the adult mice by immunofluorescence shows that Spnr protein is expressed in the postmeiotic germ cells and is localized to the manchette, a spermatid-specific microtubular array. Spnr is a 71-kD protein containing two RNA binding domains. Spnr helps in the RNA transport or translational activation.

A comparison of the translational capacity of deproteinized Prm-1 mRNA extracted in an in vitro translation system from elongating and round spermatid populations reveals comparable translation efficiencies in wheat germ extracts of Prm-1 mRNAs from both spermatids, indicating the competence of Prm-1 signal in round spermatids for translation. An RNA band shift assay helps delineate an activity in meiotic spermatocyte and postmeiotic round spermatid cytoplasm, which associates with the 3'UTRs of Prm-2 and Prm-1 mRNA. The binding site is present at the 22-nt region in the Prm-1 3'UTR and at the 20-nt region in the Prm-2 3'UTR. The 3'UTRs of Prm-1 and Prm-2 mRNAs associate sequence-specifically with two germ cell proteins of 50 and 48 kDa.