Effects of polycyclic aromatic hydrocarbons on the vesicular components of brown algal reproductive stages: the use of vital dyes and histochemical methods

Little research into the responses of marine algal reproductive stages to xenobiotics has been undertaken at the cellular level. It is hoped this reported research will help initiate an integrated approach of pollution responses in marine organisms. Eukaryotic lysosomes are known to accumulate the vital dyes Neutral Red and Acridine Orange with histochemical methods relying on the presence of several lysosomal hydrolases. Attempts were made to visualise lytic activities using the above techniques in eggs and zygotes of the marine alga Fucus serratus L to permit subsequent analysis of their responses to xenobiotic exposure. Newly released F. serratus eggs appeared to accumulation Neutral Red in the abundant polyphenolic storage vesicles known as physodes. Acridine Orange accumulated in vesicles similar to those stained by Neutral Red. Endogenous polyphenolic materials hampered the histochemical methods for detecting lysosomal acid phosphatase with indoxyl methods for non-specific esterases revealing enzyme activity within the lipid bodies of the eggs. The esterase vesicles were different in size and distribution to those revealed by Neutral Red and Acridine Orange. The effects of polycyclic aromatic hydrocarbons on these 'esterase positive' vesicles form the basis of the work to be presented.