TL;DR: C. teleta exhibit segmental or pair-rule stripes of expression in the ectoderm or mesoderm, consistent with an independent origin of segmentation between annelids and arthropods.
Abstract: Annelids and arthropods each possess a segmented body. Whether this similarity represents an evolutionary convergence or inheritance from a common segmented ancestor is the subject of ongoing investigation. To investigate whether annelids and arthropods share molecular components that control segmentation, we isolated orthologs of the Drosophila melanogaster pair-rule genes, runt, paired (Pax3/7) and eve, from the polychaete annelid Capitella teleta and used whole mount in situ hybridization to characterize their expression patterns. When segments first appear, expression of the single C. teleta runt ortholog is only detected in the brain. Later, Ct-runt is expressed in the ventral nerve cord, foregut and hindgut. Analysis of Pax genes in the C. teleta genome reveals the presence of a single Pax3/7 ortholog. Ct-Pax3/7 is initially detected in the mid-body prior to segmentation, but is restricted to two longitudinal bands in the ventral ectoderm. Each of the two C. teleta eve orthologs has a unique and complex expression pattern, although there is partial overlap in several tissues. Prior to and during segment formation, Ct-eve1 and Ct-eve2 are both expressed in the bilaterial pair of mesoteloblasts, while Ct-eve1 is expressed in the descendant mesodermal band cells. At later stages, Ct-eve2 is expressed in the central and peripheral nervous system, and in mesoderm along the dorsal midline. In late stage larvae and adults, Ct-eve1 and Ct-eve2 are expressed in the posterior growth zone. C. teleta eve, Pax3/7 and runt homologs all have distinct expression patterns and share expression domains with homologs from other bilaterians. None of the pair-rule orthologs examined in C. teleta exhibit segmental or pair-rule stripes of expression in the ectoderm or mesoderm, consistent with an independent origin of segmentation between annelids and arthropods.
TL;DR: The morphology and mitochondrial COI gene sequences of Capitella specimens from two localities in Japan concluded that these characters vary intraspecifically, and COI data indicate that C. teleta actually occurs in both the NW Atlantic and NW Pacific.
Abstract: Capitella teleta Blake et al., 2009 is an opportunistic capitellid originally described from Massachusetts (USA), but also reported from the Mediterranean, NW Atlantic, and North Pacific, including Japan. This putatively wide distribution had not been tested with DNA sequence data; intraspecific variation in morphological characters diagnostic for the species had not been assessed with specimens from non-type localities, and the species status of the Japanese population(s) was uncertain. We examined the morphology and mitochondrial COI (cytochrome c oxidase subunit I) gene sequences of Capitella specimens from two localities (Ainan and Gamo) in Japan. Specimens from Ainan and Gamo differed from C. teleta from Massachusetts in methyl-green staining pattern, shape of the genital spines, and shape of the capillary chaetae; we concluded that these characters vary intraspecifically. Species delimitation analyses of COI sequences suggested that worms from Ainan and Massachusetts represent C. teleta; these populations share a COI haplotype. The specimens from Gamo may represent a distinct species and comprise a sister group to C. teleta s. str.; we refer to the Gamo population as Capitella aff. teleta. The average Kimura 2-parameter (K2P) distance between C. teleta s. str. and C. aff. teleta was 3.7%. The COI data indicate that C. teleta actually occurs in both the NW Atlantic and NW Pacific. Given the short planktonic larval duration of C. teleta, this broad distribution may have resulted from anthropogenic dispersal.
TL;DR: The CYP complement of the annelid Capitella teleta has been robustly identified and annotated with the genome assembly available and the most appropriate candidates for steroidogenesis genes based on their phylogeny were identified.
Abstract: The Cytochrome P450 super family (CYP) is responsible for a wide range of functions in metazoans, having roles in both exogenous and endogenous substrate metabolism. Annelids are known to metabolize polycyclic aromatic hydrocarbons (PAHs) and produce estrogen. CYPs are postulated to be key enzymes in these processes in annelids. In this study, the CYP complement (CYPome) of the annelid Capitella teleta has been robustly identified and annotated with the genome assembly available. Phylogenetic analyses were performed to understand the evolutionary relationships between CYPs in C. teleta and other species. Predictions of which CYPs are potentially involved in both PAH metabolism and steroidogensis were made based on phylogeny. Annotation of 84 full length and 12 partial CYP sequences predicted a total of 96 functional CYPs in C. teleta. A further 13 CYP fragments were found but these may be pseudogenes. The C. teleta CYPome contained 24 novel CYP families and seven novel CYP subfamilies within existing families. A phylogenetic analysis identified that the C. teleta sequences were found in 9 of the 11 metazoan CYP clans. Two CYPs, CYP3071A1 and CYP3072A1, did not cluster with any metazoan CYP clans. We found xenobiotic response elements (XREs) upstream of C. teleta CYPs related to vertebrate CYP1 (CYP3060A1, CYP3061A1) and from families with reported transcriptional upregulation in response to PAH exposure (CYP4, CYP331). C. teleta had a CYP51A1 with ∼65% identity to vertebrate CYP51A1 sequences and has been predicted to have lanosterol 14 α-demethylase activity. CYP376A1, CYP3068A1, CYP3069A1, and CYP3070A1 were the most appropriate candidates for steroidogenesis genes based on their phylogeny and warrant further analyses, though no specific aromatase (estrogen synthesis) candidates were found. Presence of XREs upstream of C. teleta CYPs may indicate a functional aryl hydrocarbon receptor in C. teleta and candidate CYPs for studies of PAH metabolism.
TL;DR: The paper focuses on the teleoperation system TeleTA with haptic feedback designed to realize haptic communication with remote human, to achieve high level of maneuverability of robot arm in unstructured environment, and to increase effectiveness of physical Human-Robot interaction.
Abstract: The paper focuses on the teleoperation system TeleTA with haptic feedback designed to realize haptic communication with remote human, to achieve high level of maneuverability of robot arm in unstructured environment, and to increase effectiveness of physical Human-Robot interaction. The human operator directs the robot arm to the target position, while manipulator sensory system provides safe physical interaction with environment. In order to achieve awareness of collision, to support operator with valuable information (stiffness and shape of contacting object), and to realize robot-mediated haptic communication, we developed the innovative tactile and haptic displays, namely, BraTact (for presenting the cutaneous information) and FlexTorque (for presenting the kinaethetic feedback).
TL;DR: A new type of tactile display that accounts for effectiveness of the information presentation, power consumption, ergonomics, and usability for particular teleoperation task was developed and revealed the most efficient vibration patterns.
Abstract: In order to achieve awareness of collision during teleoperation and to support operator with valuable information (object stiffness and shape), we elaborated approaches to object parameter identification and delivering this information to the operator's skin through tactile display. The tactile sensory ability of the remote manipulator allows collision detection and exploration of contacting object. A new type of tactile display that accounts for effectiveness of the information presentation, power consumption, ergonomics, and usability for particular teleoperation task was developed. The experimental results of object shape and stiffness presentation to the human's forearm revealed the most efficient vibration patterns.