The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
Mirna Saraga-babić - One of the best experts on this subject based on the ideXlab platform.
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Expression of PAX2 gene during human development.
The International Journal of Developmental Biology, 1998Co-Authors: Janoš Terzić, Christiane Muller, Srećko Gajović, Mirna Saraga-babićAbstract:Abstract The expression of human paired-box-containing PAX2 gene was examined in 7 human conceptuses 6 to 9 weeks old by in situ hybridization. The embryos were collected after legal abortions, embedded in paraffin, serially cut in transversal direction and treated with S35 labeled probe for PAX2. In the neural tube of 6-week embryos, PAX2 was expressed in the outer part of the ventricular zone on both sides of the Sulcus limitans. At later stages, it was expressed in the intermediate zone of the spinal cord, both in alar and basal plates except in the region of motor neuroblasts. In the brain, expression of PAX2 extended from mesencephalic-rhombencephalic border along the entire rhombencephalon in a manner similar to that described for the spinal cord. Expression of PAX2 gene in the eye was seen in the optic cup and stalk, and later in the optic disc and nerve. In the ear, expression was restricted to the part of the otic vesicle flanking the neural tube and later to the utricle and cochlea. Expression of PAX2 was observed in developing kidneys as well. During human development PAX2 has a spatially restricted expression along the compartmental boundaries of the neural tube, and within developing eye, ear and kidneys. Differentiation of those organs seems to be mediated by PAX2 gene at the defined stages of human development.
Rudolf Nieuwenhuys - One of the best experts on this subject based on the ideXlab platform.
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topological analysis of the brainstem of the bowfin amia calva
The Journal of Comparative Neurology, 1994Co-Authors: Yvonne F Heijdra, Rudolf NieuwenhuysAbstract:This paper presents a survey of the cell masses in the brainstem of the generalized actinopterygian fish Amia calva, based on transversely cut Nissl-, Kluver-Barrera-, and Bodian-stained serial sections. This study is intended to serve a double purpose. First it forms part of a now almost complete series of publications on the structure of the brainstem in representative species of all groups of vertebrates. Within the framework of this comparative program the cell masses in the brainstem and their positional relations are analyzed in the light of the Herrick–Johnston concept; according to this the brainstem nuclei are arranged in four longitudinal, functional zones or columns, the boundaries of which are marked by ventricular sulci. The procedure employed in this analysis essentially involves two steps: first, the cell masses and large individual cells are projected upon the ventricular surface, and next, the ventricular surface is flattened out, that is, subjected to a one-to-one continuous topological transformation (Nieuwenhuys [1974] J. Comp. Neurol. 156:255-267). The second purpose of the present paper is to provide a cytoarchitectonic basis for experimental analysis of the fiber connectivity in the brainstem of Amia. Five longitudinal sulci–the Sulcus medianus inferior, the Sulcus intermedius ventralis, the Sulcus limitans, the Sulcus intermedius dorsalis, and the Sulcus lateralis mesencephali–could be distinguished. Some shorter grooves, present in the isthmal region, clearly deviate from the overall longitudinal pattern of the other sulci. Although in Amia most neuronal perikarya are contained within a diffuse periventricular gray, 40 cell masses could be delineated: Eight of these are primary efferent or motor nuclei, 10 are primary afferent or sensory centers, seven are considered to be components of the reticular formation, and the remaining 15 may be interpreted as “relay” nuclei. The topological analysis yielded the following results. In the rhombencephalon the gray matter is arranged in four longitudinal columns or areas, termed area ventralis, area intermedioventralis, are intermediodorsalis, and area dorsalis. The Sulcus intermedius ventralis, the Sulcus limitans, and the Sulcus intermedius dorsalis mark the bounderies between these morphological entities. These longitudinal areas coincide largely, but not entirely, with the functional columns of Herrick and Johnston. The most obvious incongruity is that the area intermediodorsalis contains, in addition to the viscerosensory nucleus of the solitary tract, several general somatosensory and special somatosensory nuclei. The four longitudinal zones cannot be distinguished in the mesencephalon nor can the Sulcus limitans be recognized here. Functionally, however, the medial part of the tegmentum mesencephali may be considered the rostral extremity of the somatomotor column, whereas the remainder of the midbrain contains a number of somatosensory centers. © 1994 Wiley-Liss, Inc.
Jo Begbie - One of the best experts on this subject based on the ideXlab platform.
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separating early sensory neuron and blood vessel patterning
Developmental Dynamics, 2010Co-Authors: Laura C Miller, Sabine Freter, Feng Liu, Jeremy S H Taylor, Roger Patient, Jo BegbieAbstract:The anatomical association between sensory nerves and blood vessels is well recognised in the adult, and interactions between the two are important during development. Here we have examined the relationship between developing blood vessels and sensory neuronal cell bodies, which is less well understood. We show in the chick that the nascent dorsal root ganglia (DRG) lie dorsal to the longitudinal anastomosis, adjacent to the developing neural tube at the level of the Sulcus limitans. Furthermore, the blood vessel is present prior to the neurons suggesting that it may play a role in positioning the DRG. We use the zebrafish cloche mutation to analyse DRG formation in the absence of blood vessels and show that the DRG are positioned normally. Thus, despite their close anatomical relationship, the patterning of the blood vessel and DRG alongside the neural tube is separable rather than interdependent. Developmental Dynamics 239:3297–3302, 2010. V C 2010 Wiley-Liss, Inc.
Chris Kintner - One of the best experts on this subject based on the ideXlab platform.
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The role of F-cadherin in localizing cells during neural tube formation in Xenopus embryos
Development (Cambridge England), 1998Co-Authors: Amy Espeseth, George E. Marnellos, Chris KintnerAbstract:The cell adhesion molecule F-cadherin is expressed in Xenopus embryos at boundaries that subdivide the neural tube into different regions, including one, the Sulcus limitans, which partitions the caudal neural tube into a dorsal and ventral half (alar and basal plate, respectively). Here we examine the role of F-cadherin in positioning cells along the caudal neuraxis during neurulation. First, we show that ectopic expression of F-cadherin restricts passive cell mixing within the ectodermal epithelium. Second, we show that F-cadherin is first expressed at the Sulcus limitans prior to the extensive cell movements that accompany neural tube formation, suggesting that it might serve to position cells at the Sulcus limitans by counteracting their tendency to disperse during neurulation. We test this idea using an assay that measures changes in cell movements during neurulation in response to differential cell adhesion. Using this assay, we show that cells expressing F-cadherin localize preferentially to the Sulcus limitans, but still disperse when located away from the Sulcus limitans. In addition, inhibiting cadherin function prevents cells from localizing precisely at the Sulcus limitans. These results indicate that positioning of cells at the Sulcus limitans is mediated in part by the differential expression of F-cadherin.
Janoš Terzić - One of the best experts on this subject based on the ideXlab platform.
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Expression of PAX2 gene during human development.
The International Journal of Developmental Biology, 1998Co-Authors: Janoš Terzić, Christiane Muller, Srećko Gajović, Mirna Saraga-babićAbstract:Abstract The expression of human paired-box-containing PAX2 gene was examined in 7 human conceptuses 6 to 9 weeks old by in situ hybridization. The embryos were collected after legal abortions, embedded in paraffin, serially cut in transversal direction and treated with S35 labeled probe for PAX2. In the neural tube of 6-week embryos, PAX2 was expressed in the outer part of the ventricular zone on both sides of the Sulcus limitans. At later stages, it was expressed in the intermediate zone of the spinal cord, both in alar and basal plates except in the region of motor neuroblasts. In the brain, expression of PAX2 extended from mesencephalic-rhombencephalic border along the entire rhombencephalon in a manner similar to that described for the spinal cord. Expression of PAX2 gene in the eye was seen in the optic cup and stalk, and later in the optic disc and nerve. In the ear, expression was restricted to the part of the otic vesicle flanking the neural tube and later to the utricle and cochlea. Expression of PAX2 was observed in developing kidneys as well. During human development PAX2 has a spatially restricted expression along the compartmental boundaries of the neural tube, and within developing eye, ear and kidneys. Differentiation of those organs seems to be mediated by PAX2 gene at the defined stages of human development.
