About the Cover

Abstract

Next article FreeAbout the CoverPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreCoverThe cover image is a macrophotograph of the dorsal aspects of two specimens (∼1.5 cm) of the photosynthetic sacoglossan sea slug Elysia chlorotica. The emerald green color is the result of chloroplasts, called kleptoplasts, located inside the cells of the digestive tubules, where they have been taken up from the slugs’ algal food—Vaucheria litorea, in this case. The kleptoplasts are maintained intracellularly, photosynthetically capable, for many months. Elysia chlorotica can survive their entire annual life cycle and reproduce without food, using only photosynthesis. The kleptoplast maintenance mechanism uses algal nuclear genes that have been transferred into the slug genome. In addition, the E. chlorotica genome contains an endogenous retrovirus that is synchronously expressed in 100 percent of the slugs at the end of the life cycle. Any role of the virus in the chloroplast symbiosis or the life cycle is currently unknown.On pages 236–244 of this issue of The Biological Bulletin, authors Pierce, Mahadevan, Massey, and Middlebrooks report the genomic sequence of the E. chlorotica virus, and provide a phylogenetic analysis. The viral genome contains sequences matching reverse transcriptase (RT) and portions of the envelope protein of retroviruses. Although the public databases do not yet contain a great deal of comparative genomic sequence data, the virus seems to be novel. Nevertheless, the protein sequence of the E. cholortica viral RT shows similarities to those sequences in unexpressed retrotransposons of Aplysia californica and Stronglyocentrotus purpuratus.Credits: Photo, Patrick Krug, California State University, Los Angeles; cover design, LianneDunn.com. Next article DetailsFiguresReferencesCited by The Biological Bulletin Volume 231, Number 3December 2016 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.1086/691073 © 2016 by Marine Biological Laboratory. All rights reserved.PDF download Crossref reports no articles citing this article.