'My mouse has no phenotype'.

Abstract

At the recent Annual Meeting of the International Behavioural and Neural Genetics Society in San Diego, one of the symposia was devoted to the history of behavioral neurogenetics. The convener of that symposium, Stephen Maxson, gave three reasons why the history of our discipline should interest us (see Meeting Report, this issue). I would like to point to a few additional justifications. A first one is the importance of older scientific literature. There is nowadays a tendency to regard anything that appeared more than five years ago as outdated, not to mention the whole scientific literature published before the cutoff date of such indexing services as Medline. Those who are familiar with this older literature see, from time to time, studies appearing with the current authors (and the editors and referees that evaluated their manuscripts) apparently being blissfully unaware of the fact that they are treading ground already covered decades before. Another, more common, consequence of getting removed from our roots is the drift that occurs in the scientific terminology that we use. The headline of this editorial is an example of this. A phenotype is a measurable characteristic of the organism one is investigating: every mouse has a phenotype. ‘My mouse has no phenotype’ has become an unfortunate shortcut for saying that a certain mutant has a phenotype that does not deviate from control animals. This would be an unfortunate but not too serious problem if all scientists studying mutants would start using the word ‘phenotype’ in this sense. Unfortunately, this shortcut is employed mainly by researchers investigating rodent induced mutations. Yet another example is the statement that I recently saw, beginning with ‘a Quantitative Trait Locus (QTL) is a gene that (…)’. Of course, classical genetics teaches us that there is a world of difference between a locus (and a QTL is just that) and a gene. Occasionally modern jargon is being portrayed as more precise than older (and therefore presumably ‘outdated’) terminology: ‘haplosufficient’ and ‘haploinsuffient’ are sometimes used instead of dominant or recessive, although the former describe a process on the level of gene action and the latter describe the measurable effects of that process at the phenotypical level. Depending on what phenotype is studied, the effects of one and the same gene may result in a dominant or recessive phenotype. Remaining in touch with our roots prevents us from losing the knowledge that was painstakingly gathered in earlier years and helps us to keep our jargon straight, so that we will be able to continue communicating unambiguously amongst ourselves and with colleagues in other disciplines. We at Genes, Brain and Behavior will do our best to help authors use the correct terminology to present their results to a diverse public as clearly as possible.