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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2005.04.036 Byline: Brian Geldziler, Indrani Chatterjee, Andrew Singson Keywords: Fertilization; Sperm; Spermiogenesis; Spermatogenesis; C. elegans Abstract: During the process of spermiogenesis (sperm activation) in Caenorhabditis elegans, the dramatic morphological events that ultimately transform round sessile spermatids into polar motile spermatozoa occur without the synthesis of any new gene products. Previous studies have identified four genes (spe-8, spe-12, spe-27 and spe-29) that specifically block spermiogenesis and lead to hermaphrodite-specific fertility defects. Here, we report the cloning and characterization of a new component of the sperm activation pathway, spe-19, that is required for fertility in hermaphrodites. spe-19 is predicted to encode a novel single-pass transmembrane protein. The spe-19 mutant phenotype, genetic interactions and the molecular nature of the gene product suggest SPE-19 to be a candidate for the receptor/co-receptor necessary for the transduction of the activation signal across the sperm plasma membrane. Author Affiliation: Waksman Institute, Department of Genetics, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854, USA Article History: Received 28 October 2004; Revised 28 April 2005; Accepted 28 April 2005

Abstract Background Genetic deletions or deficiencies have been used for gene mapping and discovery in various organisms, ranging from the nematode Caenorhabditis elegans all the way to humans. One problem with large deletions is the determination of the location of their breakpoints. This is exacerbated in the case of complex deficiencies that delete a region of the genome, while retaining some of the intervening sequence. Previous methods, using genetic complementation or cytology were hampered by low marker density and were consequently not very precise at positioning the breakpoints of complex deficiencies. The identification of increasing numbers of Single Nucleotide Polymorphisms (SNPs) has resulted in the use of these as genetic markers, and consequently in their utilization for defining the breakpoints of deletions using molecular biology methods. Results Here, we show that SNPs can be used to help position the breakpoints of a complex deficiency in C. elegans. The technique uses a combination of genetic crosses and molecular biology to generate robust and highly reproducible results with strong internal controls when trying to determine the breakpoints of deficiencies. The combined use of this technique and standard genetic mapping allowed us to rapidly narrow down the region of interest in our attempts to clone a gene. Conclusion Unlike previous methods used to locate deficiency breakpoints, our technique has the advantage of not being limited by the amount of starting material. It also incorporates internal controls to eliminate false positives and negatives. The technique can also easily be adapted for use in other organisms in which both genetic deficiencies and SNPs are available, thereby aiding gene discovery in these other models.

Abstract: Children and adolescents comprise a significant proportion of the hemophilia population, including those patients who have developed inhibitors to factor VIII or FIX. We examine the use of rFVIIa for the treatment of bleeding episodes and the prevention of bleeding in children and adolescents with hemophilia A and B with inhibitors, focusing on registry data and recent clinical trial results. Based on this review of the literature, we conclude that recombinant FVIIa is safe and effective for use in controlling bleeding in these patient populations. [Copyright &y& Elsevier]

Background: Genetic deletions or deficiencies have been used for gene mapping and discovery in various organisms, ranging from the nematode Caenorhabditis elegans all the way to humans. One problem with large deletions is the determination of the location of their breakpoints. This is exacerbated in the case of complex deficiencies that delete a region of the genome, while retaining some of the intervening sequence. Previous methods, using genetic complementation or cytology were hampered by low marker density and were consequently not very precise at positioning the breakpoints of complex deficiencies. The identification of increasing numbers of Single Nucleotide Polymorphisms (SNPs) has resulted in the use of these as genetic markers, and consequently in their utilization for defining the breakpoints of deletions using molecular biology methods. Results: Here, we show that SNPs can be used to help position the breakpoints of a complex deficiency in C. elegans. The technique uses a combination of genetic crosses and molecular biology to generate robust and highly reproducible results with strong internal controls when trying to determine the breakpoints of deficiencies. The combined use of this technique and standard genetic mapping allowed us to rapidly narrow down the region of interest in our attempts to clone a gene. Conclusion: Unlike previous methods used to locate deficiency breakpoints, our technique has the advantage of not being limited by the amount of starting material. It also incorporates internal controls to eliminate false positives and negatives. The technique can also easily be adapted for use in other organisms in which both genetic deficiencies and SNPs are available, thereby aiding gene discovery in these other models. [ABSTRACT FROM AUTHOR]

Investigates molecular genetics approach to studying fertilization in model systems. Identification of candidate genetic sequences; Generation of a series of mutant Caenorhabditis elegans to study spermatozoa development and function; Performance of homologous recombination in Drosophila.

The ability of multiple oblique illumination (MOI) and high-definition microscopy (Edge R-400 3-D microscope) to improve resolution of cellular detail in the evaluation of cytopathological specimens of Pap smears and thyroid fine-needle aspirates (FNAs) has been demonstrated. However, previous experiments showed that the advantages of MOI and high-definition stereo microscopy were less certain for the breast FNAs. We hypothesized that these findings were due to the lack of sample thickness for the breast FNA specimens. To test this hypothesis, we analyzed breast FNA specimens that were significantly thicker (10.5 μm). The number of lights (1, 2, 3, 4) and the angle of light (+1.5, 0, -3) were varied independently, creating 12 groups. Three images at each combination of settings were digitally captured and analyzed to obtain a histogram. The coefficient of resolution (C[sub r]) was calculated to mathematically evaluate the grayscale histograms for intensities (0-255), where C[sub r] = [| I[sub M] - I[sub N] | × (N)] (I[sub M], median pixel intensity; I[sub N], measured pixel intensity; and N, number of pixels at given intensity). Mean C[sub r] values demonstrated that the angle of light obliquity was not a factor in altering the resolution and contrast (p = .9). However, there was a significant increase in resolution, as measured by mean C[sub r] values, as the number of lights was successively reduced from four lights to one light. Thus, the thicker specimen did show that increases in resolution were a significant function of the number of lights utilized. [ABSTRACT FROM AUTHOR]

Although the general events surrounding fertilization in many species are well described, the molecular underpinnings of fertilization are still poorly understood. Caenorhabditis elegans has emerged as a powerful model system for addressing the molecular and cell biological mechanism of fertilization. A primary advantage is the ability to isolate and propagate mutants that effect gametes and no other cells. This chapter provides conceptual guidelines for the identification, maintenance, and experimental approaches for the study fertility mutants., (Copyright © 2011 Elsevier Inc. All rights reserved.)