Marine Nemertean Worms for Studies of Oocyte Maturation and Aging

Many marine invertebrates are capable of providing an abundant supply of oocytes that are fertilized external to the female body, thereby making these specimens well suited for studies of development. Along with intensively analyzed model systems belonging to such groups as echinoderms, tunicates, mollusks, and annelids, various lesser-studied taxa can undergo an external mode of fertilization. For example, nemertean worms constitute a relatively small phylum of marine protostome worms whose optically clear oocytes are easily collected and fertilized in the laboratory. Thus, to help promote the use of nemertean oocytes as a potential model in embryological analyses, this chapter begins by describing general methods for obtaining adults and for handling their gametes. After presenting such protocols, this chapter concludes with some representative results obtained with these specimens by summarizing the roles played by adenosine monophosphate-activated kinase (AMPK) during oocyte maturation and by c-Jun N-terminal kinase (JNK) during oocyte aging and death.