151,220 research outputs found
A single E-box in the <i>Cel-lin-3</i> CRM is not sufficient for <i>lin-3</i> expression in the anchor cell of <i>C</i>. <i>elegans</i>.
No full text(A) New cis-regulatory lin-3 alleles with deleted E-boxL and NHR or NHR and E-boxR. (B) Quantification of vulval induction in these new mutants. Note the complete absence of any induction in the recovered lin-3 alleles (n>30). Scorings of lin-3(1417) animals are the same as those reported in Fig 5 and are used here to indicate that this mutation leads to vulval hypo-induction rather than no induction at all. (C-D) smFISH in lin-3(mf72) (C) and N2 (D) animals. Green spots correspond to lin-3 transcripts and red spots to lag-2 that is used as an anchor cell marker. Blue is DAPI staining of nuclei. Note the absence of lin-3 expression in the anchor cell in the lin-3(mf72) mutant animal. Absence of lin-3 signal in the anchor cell was also confirmed for the other lin-3 alleles.</p
Spatial Chow-Lin Methods for Data Completion in Econometric Flow Models
Full text linkFlow data across regions can be modeled by spatial econometric models, see LeSage and Pace (2009). Recently, regional studies became interested in the aggregation and disaggregation of flow models, because trade data cannot be obtained at a disaggregated level but data are published on an aggregate level. Furthermore, missing data in disaggregated flow models occur quite often since detailed measurements are often not possible at all observation points in time and space. In this paper we develop classical and Bayesian methods to complete flow data. The Chow and Lin (1971) method was developed for completing disaggregated incomplete time series data. We will extend this method in a general framework to spatially correlated flow data using the cross-sectional Chow-Lin method of Polasek et al. (2009). The missing disaggregated data can be obtained either by feasible GLS prediction or by a Bayesian (posterior) predictive density.Missing values in spatial econometrics, MCMC, non-spatial Chow-Lin (CL) and spatial Chow-Lin (SCL) methods, spatial internal flow (SIF) models, origin and destination (OD) data
SPATIAL CHOW-LIN METHODS: BAYESIAN AND ML FORECAST COMPARISONS
Full text linkCompleting data that are collected in disaggregated and heterogeneous spatial units is a quite frequent problem in spatial analyses of regional data. Chow and Lin (1971) (CL) were the rst to develop a uni ed framework for the three problems (interpolation, extrapolation and distribution) of predicting disaggregated times series by so-called indicator series. This paper develops a spatial CL procedure for disaggregating cross-sectional spatial data and compares the Maximum Likelihood and Bayesian spatial CL forecasts with the naive pro rata error distribution. We outline the error covariance structure in a spatial context, derive the BLUE for the ML estimator and the Bayesian estimation procedure by MCMC. Finally we
apply the procedure to European regional GDP data and discuss the disaggregation assumptions. For the evaluation of the spatial Chow-Lin procedure we assume that only NUTS 1 GDP is known and predict it at NUTS 2 by using employment and spatial information available at NUTS 2. The spatial neighborhood is de ned by the inverse travel time by car in minutes. Finally, we present the forecast accuracy criteria comparing the predicted values with the actual observations.
Cybaeus fushun Lin & Li 2021, sp. nov.
No full textCybaeus fushun Lin & Li, sp. nov. (Figs 15A–B, 17A–B) Diagnosis. Cybaeus fushun Lin & Li, sp. nov. can be distinguished from C. huadian Lin & Li, sp. nov. and C. songniensis Seo, 2016 by the inconspicuous COs and the same shape of the S but can be distinguished by the spiraled CDs (vs. no spirals in C. huadian Lin & Li, sp. nov. and C. songniensis), S narrowed (vs. elongate in C. huadian Lin & Li, sp. nov. and C. songniensis). Description. Female (holotype, IZCAS-Ar42408, Figs 15A–B, 17A–B). Total length 10.44. Color in alcohol: carapace, sternum, chelicerae, labium, endites, palp, and legs white with black pattern. Carapace 4.21 long, 3.50 wide. Opisthosoma 6.08 long, 4.26 wide. Fovea longitudinal. Eye sizes and interdistances: AME 0.18, ALE 0.13, PME 0.23, PLE 0.19, AME– AME 0.13, PME–PME 0.14, AME–PME 0.14, AME–ALE 0.13, PME–PLE 0.13, ALE–PLE 0.13. AER almost straight. Leg measurements: Leg I 14.00 (4.05 + 5.05 + 3.10 + 1.80), leg II 13.10 (3.60 + 4.75 + 3.00 + 1.75), leg III 11.33 (3.50 + 3.03 + 3.30 + 1.50), leg IV 14.95 (4.00 + 4.90 + 4.15 + 1.90). Leg formula 4123. Abdomen oval, spinnerets short and unsegmented. Epigyne (Figs 15A–B) wider than long. COs inconspicuous; CDs extend basally, middle of CDs with a spiral. AG distinct, at the middle of CDs. S large, oval. Male. Unknown. Material examined. Holotype ♀, China: Liaoning, Fushun, Qingyuan County, Dahulinchang, (42.5878°N, 124.9367°E; elev. ca. 350 m), 8 September 2019, leg. Yejie Lin & Pengyu Jin (IZCAS-Ar42408). Paratypes. 1♀ (IZCAS- Ar42409), same data as holotype. Distribution. Known only from the type locality. Etymology. The species name is a noun in apposition, derived from the type locality.Published as part of Lin, Yejie, Marusik, Yuri M., Gao, Caixia, Xu, Hao, Zhang, Xiaoqing, Wang, Ziyi, Zhu, Wenhui & Li, Shuqiang, 2021, Twenty-three new spider species (Arachnida: Araneae) from Asia, pp. 91-152 in Zoological Systematics 46 (2) on page 105, DOI: 10.11865/zs.2021201, http://zenodo.org/record/536706
Identification of cis-regulatory elements from the C. elegans Hox gene lin-39 required for embryonic expression and for regulation by the transcription factors LIN-1, LIN-31 and LIN-39
No full textExpression of the Caenorhabditis elegans Hox gene lin-39 begins in the embryo and continues in multiple larval cells, including the P cell lineages that generate ventral cord neurons (VCNs) and vulval precursor cells (VPCs). lin-39 is regulated by several factors and by Wnt and Ras signaling pathways; however, no cis-acting sites mediating lin-39 regulation have been identified. Here, we describe three elements controlling lin-39 expression: a 338-bp upstream fragment that directs embryonic expression in P5-P8 and their descendants in the larva, a 247-bp intronic region sufficient for VCN expression, and a 1.3-kb upstream cis-regulatory module that drives expression in the VPC P6.p in a Ras-dependent manner. Three trans-acting factors regulate expression via the 1.3-kb element. A single binding site for the ETS factor LIN-1 mediates repression in VPCs other than P6.p; however, loss of LIN-1 decreases expression in P6.p. Therefore, LIN-1 acts both negatively and positively on lin-39 in different VPCs. The Forkhead domain protein LIN-31 also acts positively on lin-39 in P6.p via this module. Finally, LIN-39 itself binds to this element, suggesting that LIN-39 autoregulates its expression in P6.p. Therefore, we have begun to unravel the cis-acting sites regulating lin-39 Hox gene expression and have shown that lin-39 is a direct target of the Ras pathway acting via LIN-1 and LIN-31..SC: 0S; 7B; 0T; CA; PE; EC; SO; AA; XURL: URL; E-MAIL; DOI; DIGITAL-OBJECT-IDENTIFIERSource type: Electronic(1)[email protected]; http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WDG-4K0C9JV-3&_user=10&_coverDate=09%2F15%2F2006&_rdoc=21&_fmt=summary&_orig=browse&_srch=doc-info(%23toc%236766%232006%23997029997%23633147%23FLA%23display%23Volume)&_cdi=6766&_sort=d&_docanchor=&view=c&_ct=24&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=3e6063983fd5b459eac74b274375875e; http://upei-resolver.asin-risa.ca?sid=SP:CABI&id=pmid:&id=doi%3a10.1016%2fj.ydbio.2006.05.008&issn=0012-1606&isbn=&volume=297&issue=2&spage=550&pages=550-565&date=2006&title=Developmental%20Biology&atitle=Identification%20of%20cis-regulatory%20elements%20from%20the%20C.%20elegans%20Hox%20gene%20lin-39%20required%20for%20embryonic%20expression%20and%20for%20regulation%20by%20the%20transcription%20factors%20LIN-1%2c%20LIN-31%20and%20LIN-39.&aulast=Wagmaister&pid=%3Cauthor%3EWagmaister%2c%20J%20A%3bMiley%2c%20G%20R%3bMorris%2c%20C%20A%3bGleason%2c%20J%20E%3bMiller%2c%20L%20M%3bKornfeld%2c%20K%3bEisenmann%2c%20D%20M%3C%2Fauthor%3E%3CAN%3E20073040429%3C%2FAN%3E%3CDT%3EJournal%20article%3C%2FDT%3
Differential roles of the microRNA let-7 in C. elegans tissue development
Full text linkThe organs and tissues of the human body comprise of an astonishing variety of cells as different in morphology and function as muscle cells and neurons. Amazingly, despite their different protein contents, they largely contain the identical genomic information. In order to understand the processes that enable this differentiation, we need to determine the underlying regulatory mechanisms. A very recent discovery in this context was the posttranscriptional regulation of gene expression by microRNAs (miRNAs). miRNAs are small RNA molecules that mediate translational repression and degradation of mRNA transcripts through partial complementarity to their 3’ untranslated region (UTR) . Among the first miRNAs to be identified, let-7 stands out for its high conservation in sequence and developmental functions in development throughout the animal kingdom. During my PhD, I studied the role of let-7 in Caenorhabditis elegans in the context of two distinct processes of tissue development, namely differentiation of the epidermis (called hypodermis), and morphogenesis of the vulva. The functions of the let-7 miRNA in formation of the adult cuticle have been extensively studied and are well understood. let-7 controls differentiation of specific, mitotically active epidermal cells by inducing cell cycle exit, fusion, and switch to an adult specific transcriptional program upon repression of targets such as lin-41, daf-12, hbl-1 and let-60/ras. I set out to identify novel interactors of let-7 in a genome-wide RNAi screen for suppression of the lethal let-7 bursting phenotype. Candidates were then verified using fluorescence-based reporter systems for onset of hypodermis differentiation and intensity of repression of a known target. Thereby, I was able to validate a whole set of novel members of the let-7 network, comprising genes downstream in the pathway as well as potential regulators of let-7 activity. Notably, both groups of repressors contain factors required for cell cycle progression and mitosis, which indicates an active crosstalk between let-7 and the cell-cycle machinery. In a second project, I explored the molecular basis for the prominent let-7 vulval bursting phenotype. Despite the absence of overproliferation or any other obvious phenotype in vulval morphogenesis, I was able to show that let-7 activity is required in the vulva, and that its major function in this context is repression of a single target, namely lin-41. Disruption of let-7 binding to lin-41 through modification of the let-7 complementary sites by CRISPR/Cas9 mediated genome editing suffices to trigger the bursting phenotype, proving that repression of a single target is the key function of the miRNA in this context. In summary, my work shows that while both differentiation of hypodermis as well as vulval integrity are mediated through repression of lin-41, the downstream effect of this regulation seem to differ, suggesting that let-7 can be wired to control distinct processes depending on the cellular context. With respect to the latest findings both in C. elegans as well as in mammals, it will be interesting to determine if this depends on differential molecular functions of LIN-41 in the two tissues
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<it>lin-12 </it>Notch functions in the adult nervous system of <it>C. elegans</it>
Full text linkAbstract Background Notch signaling pathways are conserved across species and traditionally have been implicated in cell fate determination during embryonic development. Notch signaling components are also expressed postdevelopmentally in the brains of adult mice and Drosophila. Recent studies suggest that Notch signaling may play a role in the physiological, rather than developmental, regulation of neurons. Here, we investigate a new non-developmental role for Caenorhabditis elegans lin-12 Notch signaling in neurons regulating the spontaneous reversal rate during locomotion. Results The spontaneous reversal rate of C. elegans during normal locomotion is constant. Both lin-12 gain and loss of function mutant animals had significantly increased reversal rates compared to wild type controls. These defects were caused by lin-12 activity, because the loss of function defect could be rescued by a wild type lin-12 transgene. Furthermore, overexpression of lin-12 recapitulated the gain-of-function defect. Increasing or decreasing lin-12 activity in the postdevelopmental adult animal was sufficient to rapidly and reversibly increase reversals, thereby excluding a developmental role for lin-12. Although lin-12 is expressed in the vulval and somatic gonad lineages, we find that these tissues play no role in regulating reversal rates. In contrast, altering lin-12 activity specifically in the nervous system was sufficient to increase reversals. These behavioral changes require components of the canonical lin-12 signaling cascade, including the ligand lag-2 and the transcriptional effector lag-1. Finally, the C. elegans AMPA/kainate glutamate receptor homolog glr-1 shows strong genetic interactions with lin-12, suggesting that glr-1 and/or other glutamate gated channels may be targets of lin-12 regulation. Conclusion Our results demonstrate a neuronal role for lin-12 Notch in C. elegans and suggest that lin-12 acutely regulates neuronal physiology to modulate animal behavior, without altering neuronal cell fate specification or neurite outgrowth. This is consistent with a role for Notch signaling in neurological disease with late onset symptoms.</p
Munidopsis sarissa Lin, Osawa & Chan 2007
No full textMunidopsis sarissa Lin, Osawa & Chan, 2007 Munidopsis sarissa Lin et al., 2007: 167, figs 1–3 (Taiwan, 960–1010 m). Type data: holotype, male, NTOU A008820. Type locality: Taiwan, 22º17.16´N, 119º59.91´E, 960–972 m.Published as part of Baba, Keiji, Macpherson, Enrique, Poore, Gary C. B., Ahyong, Shane T., Bermudez, Adriana, Cabezas, Patricia, Lin, Chia-Wei, Nizinski, Martha, Rodrigues, Celso & Schnabel, Kareen E., 2008, Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura-families Chirostylidae, Galatheidae and Kiwaidae), pp. 1-220 in Zootaxa 1905 (1) on page 158, DOI: 10.11646/zootaxa.1905.1.1, http://zenodo.org/record/513458
Munidopsis dentifalx Osawa, Lin & Chan 2007
No full textMunidopsis dentifalx Osawa, Lin & Chan, 2007 Munidopsis dentifalx Osawa, Lin & Chan, 2007: 15, figs 1–3 (between Negros and Mindanao, Philippines, 2120–2323 m). Type data: holotype, ovigerous female, NMCR. Type locality: Philippines, 8°49.6´N, 123°02.6´E, 2120–2149 m.Published as part of Baba, Keiji, Macpherson, Enrique, Poore, Gary C. B., Ahyong, Shane T., Bermudez, Adriana, Cabezas, Patricia, Lin, Chia-Wei, Nizinski, Martha, Rodrigues, Celso & Schnabel, Kareen E., 2008, Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura-families Chirostylidae, Galatheidae and Kiwaidae), pp. 1-220 in Zootaxa 1905 (1) on page 140, DOI: 10.11646/zootaxa.1905.1.1, http://zenodo.org/record/513458
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