Anne Mehlin Sørensen

Origin of the balanomorph barnacles (Crustacea, Cirripedia, Thoracica): new evidence from the Late Cretaceous (Campanian) of Sweden

New material of thoracican cirripedes, traditionally assigned to Brachylepadomorpha and basal Balanomorpha, is described from abundant isolated plates collected from sediment deposited between boulders on a rocky coastline of Late Campanian age (c. 80 Ma) at Ivö Klack in Scania, southern Sweden. Two new genera, Epibrachylepas Gale gen. nov. and Parabrachylepas Gale gen. nov. (type species P. ifoensis Withers, 1935) are described, as is a new species, Epibrachylepas newmani Gale sp. nov. Pachydiadema cretacea Withers, 1935 and Brachylepas guascoi (Bosquet, 1857) are redescribed on the basis of extensive new material. It is concluded that the long-held homologies between lateral plates of pedunculate cirripedes and balanomorphs are incorrect, and a new nomenclature is proposed for the latter group. Cladistic analysis based on 40 morphological characters of 12 species yields a consensus tree showing successive Brachylepas species and Pachydiadema as sister taxa to the crown group balanomorphs, which are here called Neobalanomorpha Gale suborder nov. Both ‘Brachylepadomorpha’ and ‘Brachylepadidae’ are paraphyletic, and together with P. cretacea form a morphocline leading from pedunculate ancestors (Pycnolepas articulata), through to basal sessile forms (B. naissanti, B. guascoi) and on to taxa identified as basal balanomorphs (Parabrachylepas, Epibrachylepas, Pachydiadema). The functional significance of the progressive changes is discussed with reference to living taxa. It is suggested that the radiation of Neobalanomorpha, dominant shallow water thoracicans in the Cenozoic, postdated the K-Pg near-extinction of more basal sessile barnacle groups. http://zoobank.org/urn:lsid:zoobank.org:pub:BB41A405-C0AE-472D-AD09-77D39C6A32FC

Neutralization epitopes on HIV pseudotyped with HTLV-I

One mechanism for expanding the cellular tropism of human immunodeficiency virus (HIV) in vitro is through formation of phenotypically mixed particles (pseudotypes) with human T lymphotropic virus type I (HTLV-I). In this study we found that pseudotypes allow penetration of HIV particles into CD4-negative cells, previously nonsusceptible to HIV infection. The infection of CD4-negative cells with pseudotypes could be blocked with anti-HTLV-I serum but failed to be significantly inhibited with anti-HIV serum or a V3-neutralizing anti-gp120 monoclonal antibody. This may represent a possibility for pseudotypes to escape neutralization by the immune system in vivo. Previous reports have suggested that carbohydrate structures may be conserved neutralization epitopes on retroviruses. In this study, the neutralizing capacity of lectins and anti-carbohydrate monoclonal antibodies was found to block infection by cell-free pseudotypes in CD4-negative cells. We suggest that although viral cofactors might expand the tropism of HIV in vivo, HIV and HTLV-I seem to induce common carbohydrate neutralization epitopes.