Basic research on herpes simplex viruses: are mutants still needed?

To the Editor Herpes viruses are present as blind passengers in the majority of humans and occasionally manifest themselves as insidious foes. When studying biological processes of herpes simplex viruses in host cells our research group enormously benefitted from a considerable number of virus mutants, that had been expertly isolated/constructed in several notable institutions. Now, we have come to the assessment, that exploiting the scientific potentials of these highly valuable tools would by far exceed our own means. The collection consists of 49 mutants derived from HSV-1 and HSV-2 standard laboratory strains (Annex I). The affected gene functions have been identified in 28 mutants. The remaining mutants have been partially characterized physically, genetically and/or phenotypically. Forty-one of the 49 mutants have a temperature-sensitive phenotype, ideally suitable for studying dynamic processes in infected cells. They can be propagated at 33 °C, and their genetic lesions are lethal at 39 °C. The parental wild-type strains do grow at both temperatures. While all mutants were plaque-purified we strongly recommend to regularly check for mycoplasma when preparing own stocks, as this was not regularly done for all original stocks. While the phenotypes of all strains are characterized and the majority of strains has literature reference, no full length sequences have been published or deposited, yet. Informations on the isolation history (scientist/institution), genetic defect, and prior use in research projects may be found in the Annex I to this letter. Virus samples may be provided by our Institute under the conditions that a mutant (i) must not be renamed and (ii) its origin must be named (i.e. investigator and institution), when used in a project/ publication. It is also foreseen to deposit the variants at the UK culture collection virus biobank (www. cultu recol lecti ons. org. uk) for non-commercial usage.


To the Editor
Herpes viruses are present as blind passengers in the majority of humans and occasionally manifest themselves as insidious foes.
When studying biological processes of herpes simplex viruses in host cells our research group enormously benefitted from a considerable number of virus mutants, that had been expertly isolated/constructed in several notable institutions. Now, we have come to the assessment, that exploiting the scientific potentials of these highly valuable tools would by far exceed our own means.
The collection consists of 49 mutants derived from HSV-1 and HSV-2 standard laboratory strains (Annex I).
The affected gene functions have been identified in 28 mutants. The remaining mutants have been partially characterized physically, genetically and/or phenotypically.
Forty-one of the 49 mutants have a temperature-sensitive phenotype, ideally suitable for studying dynamic processes in infected cells. They can be propagated at 33 °C, and their genetic lesions are lethal at 39 °C. The parental wild-type strains do grow at both temperatures.
While all mutants were plaque-purified we strongly recommend to regularly check for mycoplasma when preparing own stocks, as this was not regularly done for all original stocks. While the phenotypes of all strains are characterized and the majority of strains has literature reference, no full length sequences have been published or deposited, yet.
Informations on the isolation history (scientist/institution), genetic defect, and prior use in research projects may be found in the Annex I to this letter. Virus samples may be provided by our Institute under the conditions that a mutant (i) must not be renamed and (ii) its origin must be named (i.e. investigator and institution), when used in a project/ publication. It is also foreseen to deposit the variants at the UK culture collection virus biobank (www. cultu recol lecti ons. org. uk) for non-commercial usage.

Preface
Our investigations on herpesviral interactions with host cells have been enabled by virus mutants we had gratefully received from several renowned virologists (see list below). Having realized the high value of temperature-sensitive (ts) virus mutants for many kinds of research projects, we are carefully keeping them stored for a potential use by any scientist in future. They may be provided by the Institute of Virology at Bonn under the condition that the mutant (i) must not be renamed, and the institution with the investigator who isolated it (ii) must be mentioned if published. The references (numbers in brackets) are but a tiny selection of published data on the mutants in our collection. Further specific or general information, e.g. on handling of mutants, may be requested from us (see address for correspondence).
HSV-1 in1411/lethal mutation in the major transactivating protein ICP4/constructed by N. D. Stow, Glasgow: termination codon inserted at position 82 > truncated polypeptide; propagation of virus requires complementing cells expressing ICP4/used in research project: Host cell stress protein activation [26]; HSV-induced morphological transformation of host cells [19].
Schaffer, Boston/ used in research project: viral and host cell DNA synthesis [28].
Derivative of parental strain HSV-2 186 tsH9/ts lesion in major DNA-binding protein/isolated by D. J. M. Purifoy/ used in research project: Complementation analyses [5]. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/.