The Weight of the Spring: The Unbearable Lightness of Being and the Fate of the Prague Spring

Two of the many watershed events Czechoslovakia experienced in the twentieth century were the 1968 Prague Spring and the Warsaw Pact Invasion, which determined the course of the nation for the next twenty years. Czech author Milan Kundera experienced these events firsthand and recounted a narrative of the events in his 1984 novel The Unbearable Lightness of Being. Today, the novel remains an important work for its representation of the Spring and its philosophical discussion of the purpose of human life. Over the last fifty years, the Prague Spring has been represented by a variety of sources as a time of hopes raised and dashed, as a success and a failure, as a point of pride and shame. Its representation varies based on the political context of the day, though the idea of truth remains an important theme in the Spring\u27s evaluation. The Spring\u27s and the Invasion\u27s inherent juxtapositions remain critical for a consideration of the nature of politics and destiny

A Secret in the Words Tales of Literature and Dissent in Communist Czechoslovakia

In order to better understand the parallel culture of the 1970s and 1980s Czechoslovakia, this paper aims to tell the stories of six members of the Czechoslovak samizdat community: Marie Klimešová, Ivan Lamper, Ladislav Šenkyřík, Tomáš Tichák, Jáchym Topol, and Jarka Vrbová. Through personal interviews with these individuals, we understand how editors, typists, artists, writers, translators, and readers played significant parts in this parallel culture as well as how these people continue to play important roles in society today. While the tales told here are only parts of the lives of six individuals, they help reflect the impact of an entire culture that led to the Velvet Revolution in 1989

Restoration of spermatogenesis and male fertility using an androgen receptor transgene

Androgens signal through the androgen receptor (AR) to regulate male secondary sexual characteristics, reproductive tract development, prostate function, sperm production, bone and muscle mass as well as body hair growth among other functions. We developed a transgenic mouse model in which endogenous AR expression was replaced by a functionally modified AR transgene. A bacterial artificial chromosome (BAC) was constructed containing all AR exons and introns plus 40 kb each of 5' and 3' regulatory sequence. Insertion of an internal ribosome entry site and the EGFP gene 3' to AR allowed co-expression of AR and EGFP. Pronuclear injection of the BAC resulted in six founder mice that displayed EGFP production in appropriate AR expressing tissues. The six founder mice were mated into a Sertoli cell specific AR knockout (SCARKO) background in which spermatogenesis is blocked at the meiosis stage of germ cell development. The AR-EGFP transgene was expressed in a cyclical manner similar to that of endogenous AR in Sertoli cells and fertility was restored as offspring were produced in the absence of Sertoli cell AR. Thus, the AREGFP transgene under the control of AR regulatory elements is capable of rescuing AR function in a cell selective, AR-null background. These initial studies provide proof of principle that a strategy employing the AR-EGFP transgene can be used to understand AR functions. Transgenic mice expressing selective modifications of the AR-EGFP transgene may provide crucial information needed to elicit the molecular mechanisms by which AR acts in the testis and other androgen responsive tissues

Expression of the AR-EGFP transgene rescues full spermatogenesis in a SCARKO background.

<p>Testes cross sections stained with PAS-Hematoxylin are shown for postnatal day 105 mouse littermates (founder 2464) that express only Cre recombinase (Control), Cre recombinase in the presence of a floxed AR gene (SCARKO), and a SCARKO mouse expressing the AR-EGFP transgene (Rescue). Bars = 100 μm, magnification: 40x objective.</p

The AR-EGFP transgene increases testis weights in rescue mice.

<p>A) Agarose gel analysis is shown of PCR reactions used to genotype mice employed primers that identify the AR-EGFP transgene (tg), the Cre recombinase (Cre) or floxed endogenous AR (AR flox) and the AR transgene (AR tg). Mouse strains were identified that expressed no transgenes (wild type, wt), the Cre recombinase (Cre), a floxed AR gene (AR flox) as well as SCARKO and rescue mice. Mice expressing the AR-EGFP transgene (tg), the transgene + Cre (Tg + CRE) or the transgene in the presence of a floxed AR gene (Tg + AR flox) also were identified. The sizes of DNA markers in base pairs (bp) are shown below each gel image. B) Testis weight/body weights are provided for mice expressing the transgenes as described in A. C) The testis weight/body weight for the individual rescue mouse strains are shown relative to the same wt and SCARKO values used in panel B. Values with different lowercase letters differ significantly (P<0.05). Panel B, n = 6 to 39, panel C, n = 3 to 14).</p

Summary of spermatogenesis rescue by specific founder strains.

<p>No spermatids present</p><p>+ A few elongated spermatids present</p><p>++ Complete spermatogenesis in >10% of tubule cross sections</p><p>+++ Complete spermatogenesis in >50% of tubule cross sections</p><p>++++ Complete spermatogenesis in >90% of tubule cross sections</p><p>Summary of spermatogenesis rescue by specific founder strains.</p

Characterization of three BACs containing parts of the AR gene.

<p>(A) Top: a map of the AR gene and flanking region is shown. Below: maps of the BACs mAR BAC-196 (RP23-102011), mAR BAC-192 (RP24-352D1) and mAR BAC-185 (RP23-316P7) are shown. AR exons are denoted by rectangles on the lines. <i>SalI</i> restiction sites are denoted with an S. Boxes above exons 1 and 8 denote the probes used for Southern blotting. The BACs contained either extended 5’ sequence, the complete AR gene or extended 3’ sequence, respectively. The BACs were end sequenced to determine their insertion sites. (B) Restriction digests followed by PFGE and Southern blotting were performed to ensure that preperations of the BACs were correct. The <i>SalI</i> digested BACs were fractionated by PFGE and subjected to Southern blotting using ³²P random primed labelled AR exon 1 and AR exon 8 probes. mAR BAC-192 was positive for both probes while mAR BAC-196 only probed positive for exon 8 and mAR BAC-185 probed positive only for exon1.</p