bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression analysis of chick Wnt and frizzled genes and selected inhibitors in early chick patterning
Authors: Chapman Susan C. , Brown Ryan , Lees Lydia , Schoenwolf Gary C. , Lumsden Andrew 
Published: February 2004

AbstractWnt signaling is an important component in patterning the early embryo and specifically the neural plate. Studies in Xenopus, mouse, and zebrafish have shown that signaling by members of the Wnt family of secreted signaling factors, their Frizzled receptors and several inhibitors (sFRP1, sFRP2, sFRP3/Frzb1, Crescent/Frzb2, Dkk1, and Cerberus) are involved. However, very little is known about the expression of genes in the Wnt signaling pathway during early anterior neural patterning in chick. We have performed an expression analysis at neural plate stages of several Wnts, Frizzled genes, and Wnt signaling pathway inhibitors using in situ hybridization. The gene expression patterns of these markers are extremely dynamic. We have identified two candidate molecules for anterior patterning of the neural plate, Wnt1 and Wnt8b, which are expressed in the rostral ectoderm at these stages. Further functional studies on the roles of these markers are underway. Developmental Dynamics 229:668–676, 2004. © 2004 Wiley‐Liss, Inc.
Immunoglobulin gene conversion: Insights from bursal B cells and the DT40 cell line
Authors: Arakawa Hiroshi , Buerstedde Jean‐Marie 
Published: February 2004

AbstractChicken B cells diversify their immunoglobulin (Ig) light and heavy chain genes by pseudogene templated gene conversion within the bursa of Fabricius. Although Ig gene conversion was initially believed to occur only in birds, it is now clear that most farm animals also use this elegant mechanism to develop an immunoglobulin gene repertoire. The best model to study Ig gene conversion remains the chicken Ig light chain locus due to its compact size and the fact that all the pseudogene donors are sequenced. Furthermore, gene conversion continues in the bursa‐derived DT40 cell line whose genome can be easily modified by targeted integration of transfected constructs. Disruption of the AID gene, which had been shown to control somatic hypermutation and switch recombination in mammals leads to a complete block of gene conversion in DT40 indicating that all B‐cell specific repertoire formation is controlled by the same gene. Here, we review the genetics and the molecular mechanism of Ig gene conversion based on sequence analysis of bursal B cells and gene disruption studies in the DT40 cell line. Developmental Dynamics 229:458–464, 2004. © 2004 Wiley‐Liss, Inc.
Sonic hedgehog patterning in chick neural plate is antagonized by a Wnt3‐like signal
Authors: Robertson Christie P. , Braun Michelle M. , Roelink Henk 
Published: February 2004

AbstractSonic hedgehog (Shh) patterns the dorsal‐ventral axis of the neural tube by promoting the differentiation of ventral neural cell types while suppressing dorsal neural fates. Other signals impinge upon the Shh response, biasing the differentiation of a cell. Three dorsally expressed transforming Wnts, of which the most broadly expressed is Wnt3, may be among the signals that influence the Shh response. We demonstrate that activation of Wnt signaling results in an inhibition of the Shh response in neural tissue. Additionally, we show that the expression pattern of chick Wnt3 is consistent with a role in neural patterning. These results indicate that differentiating neural tube cells, besides integrating signals from Hedgehogs and BMPs, may also incorporate a Wnt response to make cell fate decisions. Developmental Dynamics 229:510–519, 2004. © 2004 Wiley‐Liss, Inc.
Isolation of the chicken Lmbr1 coding sequence and characterization of its role during chick limb development
Authors: Maas Sarah A. , Fallon John F. 
Published: February 2004

AbstractIn the developing amniote limb, anteroposterior (A/P) patterning is controlled through secretion of the Sonic Hedgehog (SHH) protein by cells in the zone of polarizing activity (ZPA) located in the posterior mesoderm. In the chicken mutant oligozeugodactyly (ozd), Shh is expressed normally in the entire embryo with the exception that it is undetectable in the developing limbs; this results in the loss of specific bones in wings and legs. The ozd phenotype is similar to that of humans affected with acheiropodia (ACHR), and the ACHR mutation has been mapped to a deletion of exon 4 and portions of introns 3 and 4 in the LMBR1 gene. We have cloned the chick ortholog of LMBR1, Lmbr1, and report that, in chick, Lmbr1 is expressed within the ZPA. Although the ozd phenotype is similar to ACHR, the open reading frame of Lmbr1 is normal in ozd. Sequence analysis of Lmbr1 intron 3 demonstrated that this particular genomic region segregates with the ozd phenotype. In addition, overexpression of Lmbr1 throughout the developing limb mesoderm resulted in morphologically normal limbs. Collectively, these data suggest that the Lmbr1 coding sequence is not required for normal chick limb development. We propose that the ozd mutation is linked to the genomic region containing Shh and Lmbr1. Developmental Dynamics 229:520–528, 2004. © 2004 Wiley‐Liss, Inc.
GEISHA, a whole‐mount in situ hybridization gene expression screen in chicken embryos
Authors: Bell George W. , Yatskievych Tatiana A. , Antin Parker B. 
Published: February 2004

AbstractDespite the increasing quality and quantity of genomic sequence that is available to researchers, predicting gene function from sequence information remains a challenge. One method for obtaining rapid insight into potential functional roles of novel genes is through gene expression mapping. We have performed a high throughput whole‐mount in situ hybridization (ISH) screen with chick embryos to identify novel, differentially expressed genes. Approximately 1,200 5′ expressed sequence tags (ESTs) were generated from cDNA clones of a Hamburger and Hamilton (HH) stage 4–7 (late gastrula) chick embryo endoderm–mesoderm library. After screening to remove ubiquitously expressed cDNAs and internal clustering and after comparison to GenBank sequences, remaining cDNAs (representing both characterized and uncharacterized genes) were screened for expression in HH stage 3–14 embryos by automated high throughput ISH. Of 786 cDNAs for which ISH was successfully performed, approximately 30% showed ubiquitous expression, 40% were negative, and approximately 30% showed a restricted expression pattern. cDNAs were identified that showed restricted expression in every embryonic region, including the primitive streak, somites, developing cardiovascular system and neural tube/neural crest. A relational database was developed to hold all EST sequences, ISH images, and corresponding BLAST report information, and to enable browsing and querying of data. A user interface is freely accessible at http://geisha.biosci.arizona.edu. Results show that high throughput whole‐mount ISH provides an effective approach for identifying novel genes that are differentially expressed in the developing chicken embryo. Developmental Dynamics 229:677–687, 2004. © 2004 Wiley‐Liss, Inc.
Identification of ciliary epithelial‐specific genes using subtractive libraries and cDNA arrays in the avian eye
Authors: Kubota Ryo , McGuire Chris , Dierks Blair , Reh Thomas A. 
Published: February 2004

AbstractThe ciliary epithelium of the ciliary body is derived from the anterior rim of the developing optic cup. Several recent studies have found that developmental abnormalities in this tissue can underlie congenital glaucoma. However, there is little known about the development of the ciliary epithelium. To better understand the developmental events responsible for the specification of this domain of the optic cup, we used a subtractive library, differential screening approach along with the construction of cDNA arrays to identify genes expressed in the ciliary epithelium of the chicken. We identified many genes specifically expressed in the ciliary epithelium, including a number that had been described previously as enriched in the ciliary epithelium of other species. By analyzing the expression of these genes during eye development, we were able to correlate the onset of ciliary epithelial gene expression with a reduction in mitotic activity in this region. We propose that the mechanisms that regulate the expression of ciliary epithelial genes are linked to the reduction in proliferation that results in the epithelial monolayer in this region. Developmental Dynamics 229:529–540, 2004. © 2004 Wiley‐Liss, Inc.
FISHing for chick genes: Triple‐label whole‐mount fluorescence in situ hybridization detects simultaneous and overlapping gene expression in avian embryos
Authors: Denkers Nathaniel , García‐Villalba Pilar , Rodesch Christopher K. , Nielson Kandice R. , Mauch Teri Jo 
Published: February 2004

AbstractMulti‐color whole‐mount in situ hybridization is a powerful technique for comparing the spatial expression patterns of two or more genes in developing embryos. We have developed an amplified triple‐label whole‐mount fluorescence in situ hybridization (FISH) protocol that permits detection of three different mRNAs in a single embryo. Our protocol uses simultaneous in situ hybridization to haptenylated riboprobes, followed by sequential antibody detection using anti‐hapten antibodies conjugated to horseradish peroxidase, and the tyramide signal amplification (TSA) fluorescence detection system. Conventional fluorescence microscopy identifies areas of overlapping gene expression at the tissue level, whereas confocal fluorescence microscopy permits single‐cell resolution and differentiates specialized cell types within a given tissue. This protocol will provide researchers engaged in the use of FISH with a solid starting point for adapting their own in situ hybridization protocols, either alone or in combination with immunohistochemistry or green fluorescence protein colocalization. Developmental Dynamics 229:651–657, 2004. © 2004 Wiley‐Liss, Inc.
Dorsal versus ventral scales and the dorsoventral patterning of chick foot epidermis
Authors: Prin Fabrice , Logan Cairine , D'Souza Deana , Ensini Monica , Dhouailly Danielle 
Published: February 2004

AbstractThe dorsal and ventral scales of the chick foot can be distinguished morphologically and molecularly: the dorsal oblong overlapping scuta expressing both α and β keratins, and the ventral roundish nonprotruding reticula expressing only α keratins. The question arises how En‐1 and Lmx1, whose role in dorsoventral limb patterning has been well established, can affect skin morphogenesis, which occurs 8 to 12 days later. Forced expression of En‐1 or of Lmx1 in the hindlimb have, respectively, as expected, a ventralizing or a dorsalizing effect on skin, leading to the formation of either reticula‐type or scuta‐type scales on both faces. In both cases, however, the scales are abnormal and even glabrous skin without any scales at all may form. The normal inductive interactions between dermis and epidermis are disturbed after En‐1 or Lmx1 misexpression. Effectively, while Lmx1 endows the dermal precursors of the ventral region with scuta inducing ability, En‐1 blocks the competence of the dorsal epidermis to build scuta. Developmental Dynamics 229:564–578, 2004. © 2004 Wiley‐Liss, Inc.
ROCK inhibitor (Y27632) increases apoptosis and disrupts the actin cortical mat in embryonic avian corneal epithelium
Authors: Svoboda Kathy K.H. , Moessner Petra , Field Tamara , Acevedo Jesus 
Published: February 2004

AbstractThe embryonic chicken corneal epithelium is a unique tissue that has been used as an in vitro epithelial sheet organ culture model for over 30 years (Hay and Revel [1969] Fine structure of the developing Avian cornea. Basel, Switzerland: S. Karger A.G.). This tissue was used to establish that epithelial cells could produce extracellular matrix (ECM) proteins such as collagen and proteoglycans (Dodson and Hay [1971] Exp Cell Res 65:215–220; Meier and Hay [1973] Dev Biol 35:318–331; Linsenmayer et al. [1977] Proc Natl Acad Sci U S A 74:39–43; Hendrix et al. [1982] Invest Ophthalmol Vis Sci 22:359–375). This historic model was also used to establish that ECM proteins could stimulate actin reorganization and increase collagen synthesis (Sugrue and Hay [1981] J Cell Biol 91:45–54; Sugrue and Hay [1982] Dev Biol 92:97–106; Sugrue and Hay [1986] J Cell Biol 102:1907–1916). Our laboratory has used the model to establish the signal transduction pathways involved in ECM‐stimulated actin reorganization (Svoboda et al. [1999] Anat Rec 254:348–359; Chu et al. [2000] Invest Ophthalmol Vis Sci 41:3374–3382; Reenstra et al. [2002] Invest Ophthalmol Vis Sci 43:3181–3189). The goal of the current study was to investigate the role of ECM in epithelial cell survival and the role of Rho‐associated kinase (p160 ROCK, ROCK‐1, ROCK‐2, referred to as ROCK), in ECM and lysophosphatidic acid (LPA) ‐mediated actin reorganization. Whole sheets of avian embryonic corneal epithelium were cultured in the presence of the ROCK inhibitor, Y27632 at 0, 0.03, 0.3, 3, or 10 μM before stimulating the cells with either collagen (COL) or LPA. Apoptosis was assessed by Caspase‐3 activity assays and visualized with annexin V binding. The ROCK inhibitor blocked actin cortical mat reformation and disrupted the basal cell lateral membranes in a dose‐dependent manner and increased the apoptosis marker annexin V. In addition, an in vitro caspase‐3 activity assay was used to determine that caspase‐3 activity was higher in epithelia treated with 10 μM Y‐27632 than in those isolated without the basal lamina or epithelia stimulated with fibronectin, COL, or LPA. In conclusion, ECM molecules decreased apoptosis markers and inhibiting the ROCK pathway blocked ECM stimulated actin cortical mat reformation and increased apoptosis in embryonic corneal epithelial cells. Developmental Dynamics 229:579–590, 2004. © 2004 Wiley‐Liss, Inc.
Indian hedgehog and syndecans‐3 coregulate chondrocyte proliferation and function during chick limb skeletogenesis
Authors: Shimo Tsuyoshi , Gentili Chiara , Iwamoto Masahiro , Wu Changshan , Koyama Eiki , Pacifici Maurizio 
Published: February 2004

AbstractHedgehog proteins exert critical roles in embryogenesis and require heparan sulfate proteoglycans (HS‐PGs) for action. Indian hedgehog (Ihh) is produced by prehypertrophic chondrocytes in developing long bones and regulates chondrocyte proliferation and other events, but it is not known whether it requires HS‐PGs for function. Because the HS‐PG syndecan‐3 is preferentially expressed by proliferating chondrocytes, we tested whether it mediates Ihh action. Primary chick chondrocyte cultures were treated with recombinant Ihh (rIhh‐N) in absence or presence of heparinase I or syndecan‐3 neutralizing antibodies. While rIhh‐N stimulated proliferation in control cultures, it failed to do so in heparinase‐ or antibody‐treated cultures. In reciprocal gain‐of‐function studies, chondrocytes were made to overexpress syndecan‐3 by an RCAS viral vector. Cells became more responsive to rIhh‐N, but even this response was counteracted by heparinase or antibody treatment. To complement the in vitro data, RCAS viral particles were microinjected in day 4–5 chick wing buds and effects of syndecan‐3 misexpression were monitored over time. Syndecan‐3 misexpression led to widespread chondrocyte proliferation and, interestingly, broader expression and distribution of Ihh. In addition, the syndecan‐3 misexpressing skeletal elements were short, remained cartilaginous, lacked osteogenesis, and exhibited a markedly reduced expression of collagen X and osteopontin, products characteristic of hypertrophic chondrocytes and bone cells. The data are the first to indicate that Ihh action in chondrocyte proliferation involves syndecan‐3 and to identify a specific member of the syndecan family as mediator of hedgehog function. Developmental Dynamics 229:607–617, 2004. © 2004 Wiley‐Liss, Inc.
Popeye domain containing gene 2 (Popdc2) is a myocyte‐specific differentiation marker during chick heart development
Authors: Breher Stephanie S. , Mavridou Eleftheria , Brenneis Christian , Froese Alexander , Arnold Hans‐Henning , Brand Thomas 
Published: February 2004

AbstractThe Popeye domain containing (popdc) genes constitute a novel gene family encoding proteins of the plasma membrane in muscle cells, with three N‐terminal transmembrane domains and a cytoplasmic carboxy terminus. In vertebrates, three members of the Popdc gene family have been described. However, in the chick system only two cDNAs, Popdc1 and Popdc3, have been cloned previously. By screening a chick expressed sequence tag database, we report here the identification of five alternatively spliced chick Popdc2 cDNAs with different carboxy termini. Northern blot analysis revealed expression of Popdc2 predominantly in the myocardium and weaker expression in skeletal muscle. By whole‐mount in situ hybridization, chick Popdc2 was first detected at Hamburger and Hamilton (HH) stage 7 within the anterior part of the heart fields. In the tubular heart, atrial and ventricular precursor cells stained positively for Popdc2. Weaker expression was observed in myocardium of the outflow tract and sinus venosus. By HH stage 18, the outer curvature myocardium was strongly stained, whereas expression in myocardium of the inner curvature was negligible. Popdc2 expression was absent from the endocardium and propepicardial organ. At HH stage 36, Popdc2 expression was confined to the compact layer myocardium. In addition to the heart, Popdc2 expression was also observed in the myotome and in the muscle‐forming fields of the limbs. Our results indicate that Popdc2 is highly expressed in the developing heart and may serve as a novel marker of myocardial differentiation in the chick embryo. Developmental Dynamics 229:695–702, 2004. © 2004 Wiley‐Liss, Inc.
Precocious terminal differentiation of premigratory limb muscle precursor cells requires positive signalling
Authors: Venters Sara J. , Argent Rebecca E. , Deegan Fiona M. , Perez‐Baron Gina , Wong Ted S. , Tidyman William E. , Denetclaw Wilfred F. , Marcelle Christophe , Bronner‐Fraser Marianne , Ordahl Charles P. 
Published: February 2004

AbstractThe timing of myogenic differentiation of hypaxial muscle precursor cells in the somite lags behind that of epaxial precursors. Two hypotheses have been proposed to explain this delay. One attributes the delay to the presence of negative‐acting signals from the lateral plate mesoderm adjacent to the hypaxial muscle precursor cells located in the ventrolateral lip of the somitic dermomyotome (Pourquié et al. [1995] Proc. Natl. Acad. Sci. USA 92:3219–3223). The second attributes the delay to an absence of positive‐acting inductive signals, similar to those from the axial structures that induce epaxial myotome development (Pownall et al. [1996] Development 122:1475–1488). Because both studies relied principally upon changes in the expression pattern of mRNAs specific to early muscle precursor cell markers, we revisited these experiments using two methods to assess muscle terminal differentiation. First, injection of fluorescent dyes before surgery was used to determine whether ventrolateral lip cells transform from epithelial cells to elongated myocytes. Second, an antibody to a terminal differentiation marker and a new monoclonal antibody that recognises avian and mammalian Pax3 were used for immunohistochemistry to assess the transition from precursor cell to myocyte. The results support both hypotheses and show further that placing axial structures adjacent to the somite ventrolateral lip induces an axial pattern of myocyte terminal differentiation and elongation. Developmental Dynamics 229:591–599, 2004. © 2004 Wiley‐Liss, Inc.
Identification of genes regulating sensory neuron genesis and differentiation in the avian dorsal root ganglia
Authors: Nelson Branden R. , Sadhu Meru , Kasemeier Jennifer C. , Anderson Lawrence W. , Lefcort Frances 
Published: February 2004

AbstractThe dorsal root ganglia (DRG) derive from a population of migrating neural crest cells that coalesce laterally to the neural tube. As the DRG matures, discrete cell types emerge from a pool of differentiating progenitor cells. To identify genes that regulate sensory genesis and differentiation, we have designed screens to identify members from families of known regulatory molecules such as receptor tyrosine kinases, and generated full‐length and subtractive cDNA libraries between immature and mature DRG for identifying novel genes not previously implicated in DRG development. Several genes were identified in these analyses that belong to important regulatory gene families. Quantitative PCR confirmed differential expression of candidate cDNAs identified from the subtraction/differential screening. In situ hybridization further validated dynamic expression of several cDNAs identified in our screens. Our results demonstrate the utility of combining specific and general screening approaches for isolating key regulatory genes involved in the genesis and differentiation of discrete cell types and tissues within the classic embryonic chick model system. Developmental Dynamics 229:618–629, 2004. © 2004 Wiley‐Liss, Inc.
Axis I comorbidity onset and parasuicide in women with eating disorders
Authors: Wildman Prudence , Lilenfeld Lisa R.R. , Marcus Marsha D. 
Published: February 2004

AbstractObjectiveWe examined differences in the onset pattern of comorbid disorders in eating‐disordered women with and without a history of parasuicide to elucidate potential etiologic differences between the two groups.MethodsFifty‐four women with a current or past eating disorder partcipated. Of these women, 27 had a history of suicide attempts and self‐injury and 27 had no history of suicide attempts or self‐injury. The age and pattern of onset for the eating disorder relative to comorbid major depression, anxiety disorder, and substance use disorder were compared between the groups.ResultsThe onset of major depression and anxiety disorders occurred at a younger age in the parasuicidal group. In addition, the onset of major depression in the parasuicidal group occurred significantly more often before the onset of the eating disorder.DiscussionThe eating disorder may be secondary to a mood disturbance in women with parasuicidal histories. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 190–197, 2004.
Body image and eating disturbance in India: Media and interpersonal influences
Authors: Shroff Hemal , Thompson J. Kevin 
Published: February 2004

AbstractObjectiveThe current study was designed to examine the relationships among the variables of body mass index (BMI), interpersonal teasing, media internalization, body dissatisfaction, and drive for thinness in samples of young adult and middle school females from India.MethodNinety‐six adolescent and 93 adult females from Bombay, India, completed measures of body dissatisfaction, restriction, teasing history, and internalization of media images. Correlational and path analytic procedures were used to examine the data.ResultsPath analyses indicated that teasing and internalization mediated the effect of BMI on body dissatisfaction and in certain cases influenced drive for thinness.DiscussionThese findings replicate and extend previous work with U.S., Australian, and Swedish samples, suggesting that there are similar potential risk factors, cross‐culturally, that may explain the development of eating and shape‐related problems. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 198–203, 2004.