title: Aging in the colonial chordate,Botryllus schlosseri.
abstract: What mechanisms underlie aging? One theory, the wear-and-tear model, attributes aging to progressive deterioration in the molecular and cellular machinery which eventually lead to death through the disruption of physiological homeostasis. The second suggests that life span is genetically programmed, and aging may be derived from intrinsic processes which enforce a non-random, terminal time interval for the survivability of the organism. We are studying an organism that demonstrates both properties: the colonial ascidian,Botryllus schlosseri. Botryllusis a member of the Tunicata, the sister group to the vertebrates, and has a number of life history traits which make it an excellent model for studies on aging. First,Botryllushas a colonial life history, and grows by a process of asexual reproduction during which entire bodies, including all somatic and germline lineages, regenerate every week, resulting in a colony of genetically identical individuals. Second, previous studies of lifespan in genetically distinctBotrylluslineages suggest that a direct, heritable basis underlying mortality exists that is unlinked to reproductive effort and other life history traits. Here we will review recent efforts to take advantage of the unique life history traits ofB. schlosseriand develop it into a robust model for aging research.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Roma
authors.initials: R
authors.lastname: Munday
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Delany
authors.initials: D
authors.lastname: Rodriguez
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Di Maio
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Susannah
authors.initials: S
authors.lastname: Kassmer
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Braden
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Daryl A
authors.initials: DA
authors.lastname: Taketa
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Langenbacher
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, UC Santa Barbara , Santa Barbara , CA 93106 , USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: De Tomaso
keywords: aging; regeneration; stem cells; tunicate