Phillip Grote et al. (2002) West Coast Worm Meeting "Using a Combination of Two Recombinases to Create Targeted Single-copy Genomic Insertion in C. elegans"

Matthias Lauth, Michael Meyer, Phillip Grote, BARBARA CONRADT

[West Coast Worm Meeting, 2002]

The most commonly used technique to create transgenic C. elegans animals has several disadvantages for a number of applications, such as promotor studies or studies on gene regulation. Extrachromosomal arrays created by microinjection contain, for instance, the transgene at a high copy number (1). This can cause silencing and/or misregulation of the transgene. The ideal technique for creating transgenic animals (at least for some applications) would be a technique that allows the insertion of a single copy of a transgene at a specific chromosomal location.

Phillip Grote et al. (2002) European Worm Meeting "Using a Combination of Two Recombinases to Create Targeted Single- copy Genomic Insertion in C. elegans"

Matthias Lauth, Michael Meyer, BARBARA CONRADT, Phillip Grote

[European Worm Meeting, 2002]

The most commonly used technique to create transgenic C. elegans animals has several disadvantages for a number of applications, such as promotor studies or studies on gene regulation. Extrachromosomal arrays created by microinjection contain, for instance, the transgene at a high copy number (1). This can cause silencing and/or misregulation of the transgene. The ideal technique for creating transgenic animals (at least for some applications) would be a technique that allows the insertion of a single copy of a transgene at a specific chromosomal location.

Bjoern Biedermann et al. (2006) European Worm Meeting "Germline Totipotency and the worm teratoma"

Bjoern Biedermann, Rafal Ciosk, Mathias Senften

[European Worm Meeting, 2006]

Bjoern Biedermann, Matthias Senften and Rafal Ciosk. Teratomas (derived from teraton, the Greek word for monster) are germ cell tumors that contain a mixture of somatic tissue such as hair or bone. These tumors are thought to result from abnormal somatic differentiation of germ cells, but very little is known about the molecular mechanisms that normally maintain germ cell totipotency. Two conserved translational repressors, MEX-3 and GLD-1, have been recently found to maintain totipotency in the C. elegans germline (Ciosk et al., Science 311, 851, 2006). In mex-3 gld-1 mutants, germ cells transdifferentiate into various somatic cell types such as muscles or neurons. This worm teratoma requires the entry into meiosis and coincides with the disappearance of germline-specific P granules. To understand MEX-3/GLD-1 role in maintaining totipotency, we want to identify the proteins that normally need to be repressed by MEX-3 and GLD-1. Genetic and biochemical strategies will be discussed at the meeting.

Martin Gutternigg et al. (2006) European Worm Meeting "Glycosidases of Caenorhabditis elegans involved in N-glycan processing"

Martin Gutternigg, Matthias Hackl, Ute Stemmer, Iain B. H. Wilson, Petra Geier, Gunter Lochnit, Ramona Ranftl, Katharina Paschinger, Verena Jantsch, Dorothea Lubich

[European Worm Meeting, 2006]

Martin Gutternigg, Dorothea Lubich, Matthias Hackl, Katharina Paschinger, Ute Stemmer, Verena Jantsch1, Gnter Lochnit2, Ramona Ranftl, Petra Geier and Iain B. H. Wilson. Recent data indicates that in addition to the Golgi ?-mannosidases, the model nematode Caenorhabditis elegans also possesses, like insects, an N-acetylhexosaminidase activity putatively involved in N-glycan processing in the Golgi. The presence of such an activity is invoked, not just on the basis of the detected enzyme activity, but also to explain the absence of terminal N-acetylglucosamine residues on structures which require the prior action of N-acetylglucosaminyltransferase I during their biosynthesis. In order to understand the genetic basis for these activities, we have cloned cDNAs encoding members of both glycohydrolase families 20 and 38 from the worm. The encoded glycosidases were expressed in the yeast Pichia pastoris as soluble forms lacking putative cytoplasmic and transmembrane domains. Four glycohydrolase family 20 members were shown to cleave p-nitrophenyl-?-N-acetylglucosaminide and/or p-nitrophenyl-?-N-acetylgalactosaminide, but showed contrasting specificities with regard to N-glycan substrates. On the other hand, one glycohydrolase family 38 member was shown to be active using p-nitrophenyl-?-mannoside as a substrate and, in addition, had mannosidase II activity. Analysis of the glycans of the relevant mutant showed large-scale changes in the N-glycosylation spectrum. These, therefore, are the first data on the activity of Caenorhabditis glycosidases towards N-glycan substrates and should aid the further elucidation of N-glycan processing in this organism.