Cryptochrome Genes Are Highly Expressed in the Ovary of the African Clawed Frog, Xenopus tropicalis

Cryptochromes (CRYs) are flavoproteins sharing high homology with photolyases. Some of them have function(s) including transcription regulation in the circadian clock oscillation, blue-light photoreception for resetting the clock phase, and light-dependent magnetoreception. Vertebrates retain multiple sets of CRY or CRY-related genes, but their functions are yet unclear especially in the lower vertebrates. Although CRYs and the other circadian clock components have been extensively studied in the higher vertebrates such as mice, only a few model species have been studied in the lower vertebrates. In this study, we identified two CRYs, XtCRY1 and XtCRY2 in Xenopus tropicalis, an excellent experimental model species. Examination of tissue specificity of their mRNA expression by real-time PCR analysis revealed that both the XtCRYs showed extremely high mRNA expression levels in the ovary. The mRNA levels in the ovary were about 28-fold (XtCry1) and 48-fold (XtCry2) higher than levels in the next abundant tissues, the retina and kidney, respectively. For the functional analysis of the XtCRYs, we cloned circadian positive regulator XtCLOCK and XtBMAL1, and found circadian enhancer E-box in the upstream of XtPer1 gene. XtCLOCK and XtBMAL1 exhibited strong transactivation from the XtPer1 E-box element, and both the XtCRYs inhibited the XtCLOCK:XtBMAL1-mediated transactivation, thereby suggesting this element to drive the circadian transcription. These results revealed a conserved main feedback loop in the X. tropicalis circadian clockwork and imply a possible physiological importance of CRYs in the ovarian functions such as synthesis of steroid hormones and/or control of estrus cycles via the transcription regulation

Lunar Phase-Dependent Expression of Cryptochrome and a Photoperiodic Mechanism for Lunar Phase-Recognition in a Reef Fish, Goldlined Spinefoot

Lunar cycle-associated physiology has been found in a wide variety of organisms. Recent study has revealed that mRNA levels of Cryptochrome (Cry), one of the circadian clock genes, were significantly higher on a full moon night than on a new moon night in coral, implying the involvement of a photoreception system in the lunar-synchronized spawning. To better establish the generalities surrounding such a mechanism and explore the underlying molecular mechanism, we focused on the relationship between lunar phase, Cry gene expression, and the spawning behavior in a lunar-synchronized spawner, the goldlined spinefoot (Siganus guttatus), and we identified two kinds of Cry genes in this animal. Their mRNA levels showed lunar cycle-dependent expression in the medial part of the brain (mesencephalon and diencephalon) peaking at the first quarter moon. Since this lunar phase coincided with the reproductive phase of the goldlined spinefoot, Cry gene expression was considered a state variable in the lunar phase recognition system. Based on the expression profiles of SgCrys together with the moonlight's pattern of timing and duration during its nightly lunar cycle, we have further speculated on a model of lunar phase recognition for reproductive control in the goldlined spinefoot, which integrates both moonlight and circadian signals in a manner similar to photoperiodic response

A Bibliometric Analysis of the Global Research Trend in Child Maltreatment

Child maltreatment remains a major health threat globally that requires the understanding of socioeconomic and cultural contexts to craft effective interventions. However, little is known about research agendas globally and the development of knowledge-producing networks in this field of study. This study aims to explore the bibliometric overview on child maltreatment publications to understand their growth from 1916 to 2018. Data from the Web of Science Core Collection were collected in May 2018. Only research articles and reviews written in the English language were included, with no restrictions by publication date. We analyzed publication years, number of papers, journals, authors, keywords and countries, and presented the countries collaboration and co-occurrence keywords analysis. From 1916 to 2018, 47, 090 papers (53.0% in 2010–2018) were published in 9442 journals. Child Abuse & Neglect (2576 papers; 5.5%); Children and Youth Services Review (1130 papers; 2.4%) and Pediatrics (793 papers, 1.7%) published the most papers. The most common research areas were Psychology (16, 049 papers, 34.1%), Family Studies (8225 papers, 17.5%), and Social Work (7367 papers, 15.6%). Among 192 countries with research publications, the most prolific countries were the United States (26, 367 papers), England (4676 papers), Canada (3282 papers) and Australia (2664 papers). We identified 17 authors who had more than 60 scientific items. The most cited papers (with at least 600 citations) were published in 29 journals, headed by the Journal of the American Medical Association (JAMA) (7 papers) and the Lancet (5 papers). This overview of global research in child maltreatment indicated an increasing trend in this topic, with the world’s leading centers located in the Western countries led by the United States. We called for interdisciplinary research approaches to evaluating and intervening on child maltreatment, with a focus on low-middle income countries (LMICs) settings and specific contexts

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Decadal Modulation of Repeating Slow Slip Event Activity in the Southwestern Ryukyu Arc Possibly Driven by Rifting Episodes at the Okinawa Trough

We studied 38 slow slip events (SSEs) in 1997-2016 beneath the Iriomote Island, southwestern Ryukyu Arc, Japan, using continuous Global Navigation Satellite Systems data. These SSEs occur biannually on the same fault patch at a depth of similar to 30km on the subducting Philippine Sea Plate slab with average moment magnitudes (M-w) of similar to 6.6. Here we show that the slip accumulation rate (cumulative slip/lapse time) of these SSEs fluctuated over a decadal time scale. The rate increased twice around 2002 and 2013 concurrently with earthquake swarms in the Okinawa Trough. This suggests that episodic activations of the back-arc spreading at the Okinawa Trough caused extra southward movement of the block south of the trough and accelerated convergence at the Ryukyu Trench

Generation-To-Generation Transmitted Tsunami-Like Wave Sightings Along the East Coast of Taiwan

Oral tradition indicates that a tsunami-like wave occurred along the east coast of Taiwan during the middle of the 19th century. However, evidence of the event is limited. Based on interviews with local residents we obtained evidence of a tsunami-like wave from a local resident who watched the sea wave strike the coast. His account was passed down to his great granddaughter. The total number of generations between them spanned one and a half centuries. From our interviews with local residents, we observed the difficulty that people experience in retaining original memories for more than two generations. For this reason, this account of the tsunami-like wave is a valuable and rare case for the study of tsunamis along the east coast of Taiwan

Production of past-tense forms for consonant-stem and vowel-stem verbs in Japanese

1.はじめに 2.背景 3.実験 4.考察 5.おわりにAlthough previous studies have argued that two different systems—the rule-based system and the associative system—are involved in producing past-tense forms of various languages, it has not yet been clear whether the two systems are applicable to the production of past-tense forms for Japanese consonant-stem and vowel-stem verbs. A past-tense form production task revealed that past-tense forms for novel verbs patterned with those for real consonant-stem verbs, regardless of whether the novel verbs were similar to the existing vowel-stem verbs or to the consonant-verbs. The result indicated that the past-tense formation rule for consonant-stem verbs was generalized as a default and applied to novel verbs. The results of the task also indicated the frequency effect on the past-tense form production of II consonant-stem verbs and vowel-stem verbs. Although the two verbs belong to different verb groups, their dictionary forms share the same endings–iru (/iɽɯ/) or –eru (/eɽɯ/). The results indicated that the past-tense forms of the CC, CI and IC consonant-stem verbs are produced through the rule-based system, and those of the II verbs and vowel-stem verbs are produced through the associative system

日本語の五段活用動詞と一般活用動詞の過去形の生産

Although previous studies have argued that two different systems—the rule-based system and the associative system—are involved in producing past-tense forms of various languages, it has not yet been clear whether the two systems are applicable to the production of past-tense forms for Japanese consonant-stem and vowel-stem verbs. A past-tense form production task revealed that past-tense forms for novel verbs patterned with those for real consonant-stem verbs, regardless of whether the novel verbs were similar to the existing vowel-stem verbs or to the consonant-verbs. The result indicated that the past-tense formation rule for consonant-stem verbs was generalized as a default and applied to novel verbs. The results of the task also indicated the frequency effect on the past-tense form production of II consonant-stem verbs and vowel-stem verbs. Although the two verbs belong to different verb groups, their dictionary forms share the same endings–iru (/iɽɯ/) or –eru (/eɽɯ/). The results indicated that the past-tense forms of the CC, CI and IC consonant-stem verbs are produced through the rule-based system, and those of the II verbs and vowel-stem verbs are produced through the associative system.1.はじめに 2.背景 3.実験 4.考察 5.おわり