A comprehensive analysis of transposable element (TE) expression in mammalian full-grown oocytes reveals that LTR class III retrotransposons make an unexpectedly high contribution to the maternal mRNA pool, which persists in cleavage stage embryos. The most abundant transcripts in the mouse oocyte are from the mouse transcript (MT) retrotransposon family, and expression of this and other TE families is developmentally regulated. Furthermore, TEs act as alternative promoters and first exons for a subset of host genes, regulating their expression in full-grown oocytes and cleavage stage embryos. To our knowledge, this is the first example of TEs initiating synchronous, developmentally regulated expression of multiple genes in mammals. We propose that differential TE expression triggers sequential reprogramming of the embryonic genome during the oocyte to embryo transition and in preimplantation embryos.

We designed a high-density mouse genotyping array containing 623,124 SNPs that capture the known genetic variation present in the laboratory mouse. The array also contains 916,269 invariant genomic probes that are targeted to functional elements and regions known to harbor segmental duplications. The array opens the door to the characterization of genetic diversity, copy number variation, allele specific gene expression and DNA methylation and will extend the successes of human genome-wide association studies to the mouse.

Dynamic phosphorylation of the RNA polymerase II CTD repeats (YS2PTS5PS7) is coupled to transcription and may act as a “code” that controls mRNA synthesis and processing. To examine the "code" in budding yeast, we mapped genome-wide CTD S2, 5 and 7 phosphorylations (PO4) and compared them with the CTD-associated termination factors, Nrd1 and Pcf11. CTD-PO4 dynamics are not scaled to the size of the gene. At 5’ ends, the onset of S2-PO4 is delayed by about 450 bases relative to S5-PO4, regardless of gene length. Phospho-CTD dynamics are gene-specific, with high S5/7-PO4 at the 5' end being characteristic of well-expressed genes with nucleosome-occupied promoters. Furthermore, the CTD kinases Kin28 and Ctk1 profoundly affect pol II distribution along genes in a highly gene-specific way. The "code" is therefore written differently on different genes, probably under the control of promoters. S7-PO4 is enriched on introns and at sites of Nrd1 accumulation suggesting that this modification may function in splicing and Nrd1 recruitment. Nrd1 and Pcf11 frequently co-localized, suggesting functional overlap between these terminators. Surprisingly, Pcf11 is also recruited to centromeres and pol III transcribed genes.

The conceptional design of the proposed linear electron-positron collider TESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with an accelerating gradient of E acc $ 25 MV͞m at a quality factor Q 0 $ 5 3 10 9 . The design goal for the cavities of the TESLA Test Facility (TTF) linac was set to the more moderate value of E acc $ 15 MV͞m. In a first series of 27 industrially produced TTF cavities the average gradient at Q 0 5 3 10 9 was measured to be 20.1 6 6.2 MV͞m, excluding a few cavities suffering from serious fabrication or material defects. In the second production of 24 TTF cavities, additional quality control measures were introduced, in particular, an eddy-current scan to eliminate niobium sheets with foreign material inclusions and stringent prescriptions for carrying out the electronbeam welds. The average gradient of these cavities at Q 0 5 3 10 9 amounts to 25.0 6 3.2 MV͞m with the exception of one cavity suffering from a weld defect. Hence only a moderate improvement in production and preparation techniques will be needed to meet the ambitious TESLA goal with an adequate safety margin. In this paper we present a detailed description of the design, fabrication, and preparation of the TESLA Test Facility cavities and their associated components and report on cavity performance in test cryostats and with electron beam in the TTF linac. The ongoing research and development towards higher gradients is briefly addressed.

Pre-mRNA cleavage and polyadenylation is an essential step for 3′ end formation of almost all protein-coding transcripts in eukaryotes. The reaction, involving cleavage of nascent mRNA followed by addition of a polyadenylate or poly(A) tail, is controlled by cis-acting elements in the pre-mRNA surrounding the cleavage site. Experimental and bioinformatic studies in the past three decades have elucidated conserved and divergent elements across eukaryotes, from yeast to human. Here we review histories and current models of these elements in a broad range of species.