A histology-free description of a new species of the genus Tetrastemma (Nemertea: Hoplonemertea: Monostilifera) from Hawaii and India.

A new species of the genus Tetrastemma Ehrenberg, 1831, T. freyae sp. nov., is described and illustrated from Hawaii and India. The description is based on light microscopy examination of the external and internal morphology, as well as on two gene markers (cytochrome c oxidase subunit I and histone H3 DNA).

Identification of Conotoxins with Novel Odd Number of Cysteine Residues from the Venom of a Marine Predatory Gastropod Conus leopardus Found in Andaman Sea.

BACKGROUND: Conotoxins are neuro-pharmacologically active cysteine rich peptides isolated from the venom complex of marine cone snails. These are usually made of even number of cysteines. METHOD: In this study we characterised six novel conotoxin sequences from the venom of Conus leopardus collected from the Andaman Sea, namely Le907 (C-C), Le868 (C-C), Le933 (-C-CC), Le949 (-C-CC), Le1988 (C-C-CC-C) and Le1642 (CC-C-C) using de novo mass spectrometrybased sequencing methods. Astonishingly 3 of these peptides possess novel arrangements of cysteine residues with odd number of cysteines (-C-CC; C-C-CC-C), namely Le933, Le949 and Le1988. Further, a post-translational variant of peptide Le933 was identified and experimentally determined to contain hydroxyproline. RESULTS: The unusual cysteine arrangements observed suggests novel class of conotoxins. These results expand our understanding of the diversity of odd cysteine arrangements in conotoxins.