Expression Profiling without Genome Sequence Information in a Non-Model Species, Pandalid Shrimp (Pandalus latirostris), by Next-Generation Sequencing

While the study of phenotypic variation is a central theme in evolutionary biology, the genetic approaches available to understanding this variation are usually limited because of a lack of genomic information in non-model organisms. This study explored the utility of next-generation sequencing (NGS) technologies for studying phenotypic variations between 2 populations of a non-model species, the Hokkai shrimp (Pandalus latirostris; Decapoda, Pandalidae). Before we performed transcriptome analyses using NGS, we examined the genetic and phenotypic differentiation between the populations. Analyses using microsatellite DNA markers suggested that these populations genetically differed from one another and that gene flow is restricted between them. Moreover, the results of our 4-year field observations indicated that the egg traits varied genetically between the populations. Using mRNA extracted from the ovaries of 5 females in each population of Hokkai shrimp, we then performed a transcriptome analysis of the 2 populations. A total of 13.66 gigabases (Gb) of 75-bp reads was obtained. Further, 58,804 and 33,548 contigs for the first and second population, respectively, and 47,467 contigs for both populations were produced by de novo assembly. We detected 552 sequences with the former approach and 702 sequences with the later one; both sets of sequences showed greater than twofold differences in the expression levels between the 2 populations. Twenty-nine sequences were found in both approaches and were considered to be differentially expressed genes. Among them, 9 sequences showed significant similarity to functional genes. The present study showed a de novo assembly approach for the transcriptome of a non-model species using only short-read sequence data, and provides a strategy for identifying sequences showing significantly different expression levels between populations

Soft X-ray Transmission Spectroscopy of Warm/Hot Intergalactic Medium with XEUS

We discuss the detectability of Warm/Hot Intergalactic medium (WHIM) via the absorption lines toward bright point sources with a future X-ray satellite mission, XEUS. While we consider bright QSOs as specific examples, the methodology can be applied to bright GRB afterglows. We create mock absorption spectra for bright QSOs (more than 20 QSOs over the all sky) using a light-cone output of a cosmological hydrodynamic simulation. We assume that WHIM is under collisional and photo-ionization equilibrium. If WHIM has a constant metallicity of $Z=0.1Z_\odot$, approximately 2 O{\sc vii} absorption line system with $>3\sigma$ will be detected on average along a random line-of-sight toward bright QSOs up to $z=0.3$ for 30 ksec exposure.Comment: 34 pages, 17 figures. Substantial revision. PASJ, in press (2006, vol.58, August 25 issue

Comparison of Japanese and Scottish mother-infant intersubjectivity : resonance of timing, anticipation, and empathy during feeding

Feeding involves communication between mothers and infants and requires precise synchrony in a special triadic relationship with the food. It is deeply related to their intersubjectivity. This study compared the development of mother-infant intersubjectivity through interactional synchrony in feeding between 11 Japanese and 10 Scottish mother-infant dyads, observed at 6 and 9 months by video. Japanese mothers were more deliberate in feeding at an earlier age, whereas Scottish mothers were significantly more coercive than Japanese mothers at an earlier age. Japanese mothers brought the spoon to infants with a pause to adjust the timing of insertion to match their infants' readiness, whereas this pause was not observed in Scottish mothers. Isomorphic mouth opening between mothers and infants was observed. This empathic maternal display is an important element of intersubjectivity in infant feeding that differened between Scottish and Japanese mothers. Scottish mothers' mouth opening always followed their infants' mouth opening, but about half of Japanese mothers preceded their infants. Further, the mouths of Scottish infants and mothers opened almost at the same time as spoon insertion. In contrast, Japanese mothers' mouth opening did not co-ocurr with the insertion but was close to spoon arrival, a subtle but important difference that allows for greater infant autonomy. The time structure of Scottish mother-infant interactions was simpler and more predictable at 9 months than in Japan, where the structure was more variable, likely due to a stronger regulation by Scottish mothers. In conclusion, Scottish mother-infant intersubjectivity is characterised as more maternally reactive and mother-centered, whereas Japanese mother-infant intersubjectivity is characterised as more maternally empathetic and infant-centered. Cultural differences in intersubjectivity during feeding between Japan and Scotland are further discussed in relation to triadic relationships and parenting styles

Embodied inter subjective engagement in mother-infant tactile communication: a cross-cultural study of Japanese and Scottish mother-infant behaviors during infant pick-up

This study examines the early development of cultural differences in a simple, embodied, and intersubjective engagement between mothers putting down, picking up, and carrying their infants between Japan and Scotland. Eleven Japanese and ten Scottish mothers with their 6- and then 9-month-old infants participated. Video and motion analyses were employed to measure motor patterns of the mothers' approach to their infants, as well as their infants' collaborative responses during put-down, pick-up, and carry phases. Japanese and Scottish mothers approached their infants with different styles and their infants responded differently to the short duration of separation during the trial. A greeting-like behavior of the arms and hands was prevalent in the Scottish mothers' approach, but not in the Japanese mothers' approach. Japanese mothers typically kneeled before making the final reach to pick-up their children, giving a closer, apparently gentler final approach of the torso than Scottish mothers, who bent at the waist with larger movements of the torso. Measures of the gap closure between the mothers' hands to their infants' heads revealed variably longer duration and distance gap closures with greater velocity by the Scottish mothers than by the Japanese mothers. Further, the sequence of Japanese mothers' body actions on approach, contact, pick-up, and hold was more coordinated at 6 months than at 9 months. Scottish mothers were generally more variable on approach. Measures of infant participation and expressivity indicate more active participation in the negotiation during the separation and pick-up phases by Scottish infants. Thus, this paper demonstrates a culturally different onset of development of joint attention in pick-up. These differences reflect cultures of everyday interaction

SLITRK1-mediated noradrenergic projection suppression in the neonatal prefrontal cortex

SLITRK1 is an obsessive-compulsive disorder spectrum-disorders-ssociated gene that encodes a neuronal transmembrane protein. Here we show that SLITRK1 suppresses noradrenergic projections in the neonatal prefrontal cortex, and SLITRK1 functions are impaired by SLITRK1 mutations in patients with schizophrenia (S330A, a revertant of Homo sapiensspecific residue) and bipolar disorder (A444S). Slitrk1-KO newborns exhibit abnormal vocalizations, and their prefrontal cortices show excessive noradrenergic neurites and reduced Semaphorin3A expression, which suppresses noradrenergic neurite outgrowth in vitro. Slitrk1 can bind Dynamin1 and L1 family proteins (Neurofascin and L1CAM), as well as suppress Semaphorin3A-induced endocytosis. Neurofascin-binding kinetics is altered in S330A and A444S mutations. Consistent with the increased obsessive-compulsive disorder prevalence in males in childhood, the prefrontal cortex of male Slitrk1-KO newborns show increased noradrenaline levels, and serotonergic varicosity size. This study further elucidates the role of noradrenaline in controlling the development of the obsessive-compulsive disorder-related neural circuit