Meiosis: Some Considerations

Our understanding of meiosis is sturdily rooted in the well-established relationship between chromosome mechanics and genetic transmission. Yet, despite the firmness of that understanding, very little is known about the molecular mechanisms underlying the meiotic process. Such disparity is an outcome of the uneven growth in knowledge between the cytogenetics (including ultrastructure) of meiocytes and their physiology. On a priori grounds it would seem that anyone searching for an ideal experimental system to probe mechanisms of chromosome behaviour would at once turn to meiosis. The well-defined structural changes that chromosomes undergo during the process, the excellent correlation between those changes and genetic transmission, and the relatively long time interval during which the changes occur are all highly inviting targets for study. Yet even a brief survey of the field is sufficient to reveal that relatively little progress has been made in molecular studies of meiosis over the past 20 years. The intense and highly fruitful penetrations of molecular biology into a broad variety of cellular phenomena have not yet occurred in studies of meiosis. The theoretical attractiveness of the system, reinforced by the many well-characterized meiotic mutants, is not matched by a corresponding experimental attractiveness for molecular study. Available materials for molecular studies of meiosis have not been inviting, and it is this feature that has discouraged investigations. The situation will undoubtedly change because the rapid advances in experimental techniques will render the phenomenon wide open to molecular analysis.