A study of some factors affecting the efficiency of in vitro mussel tissue culture for chromosome preparation.

In the course of a series of cultures of mussel mantle tissue three types of limiting factors to the efficiency of the method were identified. They are concerned with medium composition, and tissue culture and explant harvesting procedures. To reduce their negative effects, three changes with respect to the original technique are proposed: (1) incorporation of chick embryo extract in the place of egg yolk for culture medium enrichment; (2) replacement of 1 mm2 explants by 4 mm2 explants so as to suppress centrifugation, thereby gaining time; and (3) avoiding the use of male mantle tissue when it contains mature spermatozoa since this is cumbersome for slide analysis. Conversely, female mantle tissue can be employed without any disadvantage throughout the year especially as mature oocytes give suitable metaphase plates for meiotic chromosome study.