Search

International trade of the invasive South African clawed frog (Xenopus laevis), a subclinical carrier of the fungal pathogen Batrachochytrium dendrobatis (Bd) has been proposed as a major means of introduction of Bd into naïve, susceptible amphibian populations. The historical presence of Bd in the indigenous African population of Xenopus is well documented. However, there are no reports documenting the presence of Bd in wild Xenopus populations in the US, particularly in California where introduced populations are well-established after intentional or accidental release. In this report, a survey was conducted on 178 archived specimens of 6 species of Xenopus collected in Africa from 1871–2000 and on 23 archived specimens (all wild-caught Xenopus laevis) collected in California, USA between 2001 and 2010. The overall prevalence rate of Bd in the tested Xenopus was 2.8%. The earliest positive specimen was X. borealis collected in Kenya in 1934. The overall prevalence of Bd in the X. laevis collected in California was 13% with 2 positive specimens from 2001 and one positive specimen from 2003. The positive Xenopus (3/23) collected in California were collected in 2001 (2/3) and 2003 (1/3). These data document the presence of Bd-infected wild Xenopus laevis in California. The findings reported here support the prevailing hypothesis that Bd was present as a stable, endemic infection in Xenopus populations in Africa prior to their worldwide distribution likely via international live-amphibian trade. [ABSTRACT FROM AUTHOR]

Presents abstracts of studies on initiation and restart of DNA replication, presented at the Experimental Biology/International Union of Psychological Sciences 2005 congress held in San Diego, California. "The Regulation of RecA Protein Function," by Michael M. Cox, Shelley L. Lusetti et al.; "Replication Fork Reversal by RecJ Determines if DNA Damage Is Repaired or Bypassed in E. Coli," by Justin Courcelle; "Replication-Dependent Destruction of Cdt1 Limits DNA Replication to a Single Round Per Cell Cycle in Xenopus Egg Extracts," by Emily E. Arias and Johannes C. Walter.

Presents abstracts of studies on the development of sensory systems, presented at the 2005 Experimental Biology/International Union of Physiological Sciences Congress in San Diego, California. "Xenopus Frizzled 5 Regulates the Transition of Retinal Progenitors to the Neural Precursor State," by Kathryn B. Moore, et. al.; "The Role of Notch Signaling and Radial Glia in Partnering of the Vertebrate Retina," by James M. Fadool, et. al.; "Intraflagellar Transport (IFT) proteins are Required for Photoreceptor Outer Segment Formation in the Zebrafish Retina," by Brian Perkins.

Reports on the existence of African clawed invasive frogs in Lily Pond at the Golden Gate Park in San Francisco, California. Use of the frog in scientific research; Information on the habitat and behavior of the animal; Eradication plan considered by officials involving explosives, chemicals and pond drainage.

Presents news briefs relating to biology. Production of a pharmaceutically valuable human protein in mouse milk, which is considered the first step in creating sheep, goats, or cows which can inexpensively create therapeutic proteins; Addition of the regulatory segment of a mouse milk-protein gene to the human gene for TPA, an anticlotting agent which can treat heart attacks or clotting disorders; Discovery that mucus on the skin of the African clawed frog contains certain peptides and indoleamines, known as neuromodulators, which cause predatory snakes to yawn, and that the frog may be useful in pharmacological studies designed to uncover how these chemicals affect the chemistry of the human brain and address disorders such as Parkinson's disease; Field-tests of the ability of a genetically modified form of Pseudomonas syringae bacteria to reduce frost damage to potatoes at the University of California at Berkeley.