Botryllid ascidians, a small but geographically widely distributed group of compound tunicates, are being used as a model system for the study of allorecognition. Botryllid ascidians possess a unique type of immunity. Pairs of colonies that meet through their extending ampullae either fuse to form a chimera or develop cytotoxic lesions at contact zones (rejection). This first tier of allorecogn...

The basal chordate Botryllus schlosseri undergoes a natural transplantation reaction governed by a single, highly polymorphic locus called the fuhc. Our initial characterization of this locus suggested it encoded a single gene alternatively spliced into two transcripts: a 555 amino acid-secreted form containing the first half of the gene, and a full-length, 1008 amino acid transmembrane form, w...

The Paleogene terrestrial faunal succession and its associated bearing volcaniclastic deposits has been exhaustively studied in central Patagonia, but there is still no acceptable litho-bio-chronostratigraphic ordering for the extra-Andean North Patagonia. only references on mammals north to Chubut River are imprecise contradictory. West Ingeniero Jacobacci (Río Negro Province, Argentina), pale...

The adaptive immune system in vertebrates seems to have come out of nowhere; B and T cells and mechanisms used to recognize and remember specific pathogens are missing in species that are only a step below vertebrates on the evolutionary ladder. Anthony De Tomaso is trying to figure out this puzzle, immunol-ogy's version of the big bang, using what he calls " the swing species between vertebrat...

Is Botryllus a natural killer? atural killer (NK) cells in mammals attack virus-infected and tumor cells that stop making major histocompatibility complex (MHC) proteins. But the discovery and colleagues of a protein in 1050 squirts related to a key NK cell receptor suggests that the evolutionary predecessors of NK cells may have targeted genetic interlopers of their own species. The sea squirt...

Is Botryllus a natural killer? atural killer (NK) cells in mammals attack virus-infected and tumor cells that stop making major histocompatibility complex (MHC) proteins. But the discovery and colleagues of a protein in 1050 squirts related to a key NK cell receptor suggests that the evolutionary predecessors of NK cells may have targeted genetic interlopers of their own species. The sea squirt...

A preliminary genome sequence has been assembled for the Southern Ocean salp, Salpa thompsoni (Urochordata, Thaliacea). Despite the ecological importance of this species in Antarctic pelagic food webs and its potential role as an indicator of changing Southern Ocean ecosystems in response to climate change, no genomic resources are available for S. thompsoni or any closely related urochordate s...

Recruitment is an important process in regulating many marine benthic communities and many studies have examined factors controlling the dispersal and distribution of larval immigrants. However, benthic species also have early post-settlement life-stages that are dramatically different from adult and larval stages. Predation on these stages potentially impacts measured recruitment and the benth...