Rosanna Falconi

Redox-Based Flagging of the Global Network of Oxidative Stress Greatly Promotes Longevity

Despite more than 50 years of investigations into the free radical theory, the direct role of oxidative stress (OS) in aging and age-related diseases remains unproven. Little progress in identifying antioxidant drugs promoting longevity has been made, likely due to selectivity toward one or few radical species, variable efficacy in vivo, inherent pro-oxidant behavior of such drugs, or lack of synergism with metabolic redox homeostasis. Silencing the wide range of reactive free radicals has a great impact on OS-linked outcomes and age-related disorders. Here we show that an innovative, redox-active, multi-radical-scavenger catalytic drug delays the age-associated decline in physiological processes and markedly prolongs the mean lifespan of the adult freshwater annelids Aeolosoma viride by 170%. This unprecedented extension is associated with a decreased OS status. Consistently, treatment of annelids increases their natural resistance to oxygen-derived damage without affecting mitochondrial respiration or reproductive activity. Conversely, the superoxide dismutase (SOD)-mimetic EUK 134 that we selected as a positive control led to an increase in lifespan of ~50%, the same increase previously observed in nematodes. Our results show that reduction of the global network of OS has a profound impact on aging, prompting the development of a possible redox-based therapeutic intervention to counteract the progression of aging.

Morphological Aspects of Gonadal Morphogenesis in Bufo bufo (Amphibia anura): Bidder's Organ Differentiation

We have described the architecture of Bidders organ, defined its compartmented structure, and affirmed the presence of basal laminae. We did not find morphological differences between sexes in Bidders organ. All specimens initially developed gonads with a peripheral fertile layer surrounding a thin primary cavity. The first oogenetic wave was observed early, showing all phases of meiosis, including leptotene, zygotene, and pachytene, which had been previously thought to be lacking. The peculiar presence of an asynchronous germ cell nest was discussed. Diplotene oocytes issued from the peripheral layer and migrated inside the primary cavity. They were surrounded by a single layer of follicular cells, which originated from the peripheral layer somatic cells and were delimited by a basal lamina. There were few medulla or central layer cells. At the end of metamorphosis, while the oocytes of the first oogenetic wave came into close contact with blood vessels, a second oogenetic wave took place just as the first, except for the presence of synchronous germ cell nests. The central layer was not visible and we did not observe the formation of an ovarian pocket. Stocks of stem germ cells remained in the peripheral layer during both the first and second oogenetic waves. The asymmetric model, in which there is a tendency toward a primary female differentiation, was confirmed. The female differentiation becomes stable in the Bidders organ because of the absence of further interaction between germ and medullary somatic cells, which would have led toward a male differentiation. Anat Rec, 2007.

Survival and Reproduction in Aeolosoma viride (Annelida, Aphanoneura)

We studied variability in the reproduction and survival of the zooids of Aeolosoma viride under controlled environmental conditions. Reproduction is by paratomic fission with pygidial budding. We collected data regarding the survival and reproduction of two generations of zooids (G0 and G1) raised in single cultures. Average survival was 69 days while reproductive activity varied according to the age of the specimen as well as to that of its parent at the time of fission.

Fine structure of undifferentiated gonads in Rana dalmatina tadpoles

Abstract The ultrastructure of Rana dalmatina tadpoles’ gonads is described during two early stages of development: the primary and the secondary undifferentiated condition. The gonadal bud structure in the first stage of differentiation is characterized, and it is clearly demonstrated that the cortex and the medulla are lined by an uninterrupted basal lamina along the margin adjacent to the primary cavity. The basal lamina that lines the cortex is a continuation of the one delimiting the somatopleura. In the second stage, it is shown that the medulla delaminates to form a secondary gonadal cavity known as the ovarian pocket, and that the cortex contains early germ cells, both isolated and undergoing mitotic division, corresponding to a germinal epithelium. In addition the diplotenic oocytes form a distinct layer within the primary gonadal cavity between the cortex and medulla. Each of the three layers (germinal epithelium, diplotenic oocytes, and hollow medulla) is delimited by its own basal lamina. The ultrastructure of the different germ and somatic cells is described.