Evolution of a new testis-specific functional promoter within the highly conserved MAP2K7 gene of the mouse

Map2k7(synonymMkk7) is a conserved regulatory kinase gene and a central componentof the JNK signaling cascade with key functions during cellular differentiation. It showscomplex transcription patterns, and different transcript isoforms are known in the mouse(Mus musculus). We have previously identified a newly evolved testis-specific transcript fortheMap2k7gene in the subspeciesM. m. domesticus. Here, we identify the new promoterthat drives this transcript andfind that it codes for an open reading frame (ORF) of 50 aminoacids. The new promoter was gained in the stem lineage of closely related mouse speciesbut was secondarily lost in the subspeciesM. m. musculusandM. m. castaneus. A singlemutation can be correlated with its transcriptional activity inM. m. domesticus, and cellculture assays demonstrate the capability of this mutation to drive expression. A mouseknockout line in which the promoter region of the new transcript is deleted reveals afunctional contribution of the newly evolved promoter to sperm motility and the spermatidtranscriptome. Our data show that a new functional transcript (and possibly protein) canevolve within an otherwise highly conserved gene, supporting the notion of regulatorychanges contributing to the emergence of evolutionary novelties

The genome of Romanomermis culicivorax:revealing fundamental changes in the core developmental genetic toolkit in Nematoda

Background: The genetics of development in the nematode Caenorhabditis elegans has been described in exquisite detail. The phylum Nematoda has two classes: Chromadorea (which includes C. elegans) and the Enoplea. While the development of many chromadorean species resembles closely that of C. elegans, enoplean nematodes show markedly different patterns of early cell division and cell fate assignment. Embryogenesis of the enoplean Romanomermis culicivorax has been studied in detail, but the genetic circuitry underpinning development in this species has not been explored. Results: We generated a draft genome for R. culicivorax and compared its gene content with that of C. elegans, a second enoplean, the vertebrate parasite Trichinella spiralis, and a representative arthropod, Tribolium castaneum. This comparison revealed that R. culicivorax has retained components of the conserved ecdysozoan developmental gene toolkit lost in C. elegans. T. spiralis has independently lost even more of this toolkit than has C. elegans. However, the C. elegans toolkit is not simply depauperate, as many novel genes essential for embryogenesis in C. elegans are not found in, or have only extremely divergent homologues in R. culicivorax and T. spiralis. Our data imply fundamental differences in the genetic programmes not only for early cell specification but also others such as vulva formation and sex determination. Conclusions: Despite the apparent morphological conservatism, major differences in the molecular logic of development have evolved within the phylum Nematoda. R. culicivorax serves as a tractable system to contrast C. elegans and understand how divergent genomic and thus regulatory backgrounds nevertheless generate a conserved phenotype. The R. culicivorax draft genome will promote use of this species as a research model

Enhanced genome assembly and a new official gene set for Tribolium castaneum

Background. The red flour beetle Tribolium castaneum has emerged as an important model organism for the study of gene function in development and physiology, for ecological and evolutionary genomics, for pest control and a plethora of other topics. RNA interference (RNAi), transgenesis and genome editing are well established and the resources for genome-wide RNAi screening have become available in this model. All these techniques depend on a high quality genome assembly and precise gene models. However, the first version of the genome assembly was generated by Sanger sequencing, and with a small set of RNA sequence data limiting annotation quality. Results. Here, we present an improved genome assembly (Tcas5.2) and an enhanced genome annotation resulting in a new official gene set (OGS3) for Tribolium castaneum, which significantly increase the quality of the genomic resources. By adding large-distance jumping library DNA sequencing to join scaffolds and fill small gaps, the gaps in the genome assembly were reduced and the N50 increased to 4753kbp. The precision of the gene models was enhanced by the use of a large body of RNA-Seq reads of different life history stages and tissue types, leading to the discovery of 1452 novel gene sequences. We also added new features such as alternative splicing, well defined UTRs and microRNA target predictions. For quality control, 399 gene models were evaluated by manual inspection. The current gene set was submitted to Genbank and accepted as a RefSeq genome by NCBI. Conclusions. The new genome assembly (Tcas5.2) and the official gene set (OGS3) provide enhanced genomic resources for genetic work in Tribolium castaneum. The much improved information on transcription start sites supports transgenic and gene editing approaches. Further, novel types of information such as splice variants and microRNA target genes open additional possibilities for analysis

CD44 Upregulation in E-Cadherin-Negative Esophageal Cancers Results in Cell Invasion

E-cadherin is frequently lost during epithelial-mesenchymal transition and the progression of epithelial tumorigenesis. We found a marker of epithelial-mesenchymal transition, CD44, upregulated in response to functional loss of E-cadherin in esophageal cell lines and cancer. Loss of E-cadherin expression correlates with increased expression of CD44 standard isoform. Using an organotypic reconstruct model, we show increased CD44 expression in areas of cell invasion is associated with MMP-9 at the leading edge. Moreover, Activin A increases cell invasion through CD44 upregulation after E-cadherin loss. Taken together, our results provide functional evidence of CD44 upregulation in esophageal cancer invasion

Assessment of multiple mission reusable launch vehicles

Multiple mission reusable launch vehicles could be an interesting and attractive option of the future with cost saving potential. A similar RLV-configuration capable of fulfilling very different needs might significantly reduce the development effort compared to individual developments of several dedicated crafts. The announcement of Elon Musk on the imminent development of a fully reusable two-stage launcher to LEO of very large size, called "BFR" is one spectacular example. DLR’s SpaceLiner concept is similar in certain aspects to the idea of multiple mission reusable launch vehicles. While in its primary role conceived as an ultrafast intercontinental passenger transport, in its second role the SpaceLiner is intended as an RLV capable of delivering heavy payloads into orbit. The paper provides multidisciplinary technical analyses of the different proposed multi-mission RLV-concepts. The characteristic flight conditions of winged gliding stages with those of rocket-decelerated vertical landing vehicles are compared. Performance, size and safety aspects are evaluated