| 1. |
- Afzelius, Bjorn A., et al.
(författare)
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Prevalence and genetics of immotile-cilia syndrome and left-handedness
- 2006
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Ingår i: International Journal of Developmental Biology. - : UPV/EHU Press. - 1696-3547 .- 0214-6282. ; 50:6, s. 571-573
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Tidskriftsartikel (refereegranskat)abstract
- Immotile-cilia syndrome is characterized by severe respiratory distress from early infancy, and also often by situs inversus. The first description of the disease was based on just four persons, but reasons were given to suggest that the disorder may not be exceedingly rare. The purpose of the present study was to estimate just how rare or how common it is and to evaluate its association with situs inversus and with left-handedness. Data were mainly obtained from contacting a large number of Swedish clinicians who kindly informed us about their patients with suspected immotile-cilia syndrome. Diagnosis was in most cases performed by electron micro-scopical examination of nasal cilia or of spermatozoa. Based on these data, the prevalence of the syndrome in Sweden with or without situs inversus was estimated to be not far from 1 in 10,000. The syndrome consists of several subgroups that have a randomized determination of situs asymmetry (50% of these have situs inversus) and one subgroup in which situs inversus is not found. This results in a frequency of situs inversus in the syndrome of about 44%. Left-handedness is no more common than it is in healthy persons and no more often associated with situs inversus than with situs solitus. In all cases it is about 14%. It is concluded that the two major anatomical/physiological asymmetries of the human body are found with frequencies which indicate that they develop independently of each other. Both conditions appear with prevalences that may have changed at a secular scale, left-handedness with a substantial increase and situs inversus with a less dramatic increase.
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| 2. |
- Ahmad, Nafees, et al.
(författare)
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Pitx3 directly regulates Foxe3 during early lens development.
- 2013
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Ingår i: The International journal of developmental biology. - : UPV/EHU Press. - 1696-3547 .- 0214-6282. ; 57, s. 741-751
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Tidskriftsartikel (refereegranskat)abstract
- Pitx3 is a bicoid-related homeodomain transcription factor critical for the development of the ocular lens, mesencephalic dopaminergic neurons and skeletal muscle. In humans, mutations in PITX3 are responsible for cataracts and anterior segment abnormalities of varying degree; polymorphisms are associated with Parkinsons disease. In aphakia (ak) mice, two deletions in the promoter region of Pitx3 cause abnormal lens development. Here, we investigated systematically the role of Pitx3 in lens development including its molecular targets responsible for the ak phenotype. We have shown that ak lenses exhibit reduced proliferation and aberrant fiber cell differentiation. This was associated with loss of Foxe3 expression, complete absence of Prox1 expression, reduced expression of epsilon-tubulin and earlier expression of gamma-crystallin during lens development. Using EMSA and ChIP assays, we demonstrated that Pitx3 binds to an evolutionary conserved bicoid-binding site on the 5-upstream region of Foxe3. Finally, Pitx3 binding to 5-upstream region of Foxe3 increased transcriptional activity significantly in a cell-based reporter assay. Identification of Foxe3 as a transcriptional target of Pitx3 explains at least in part some of the phenotypic similarities of the ak and dyl mice (dysgenic lens, a Foxe3 allele). These findings enhance our understanding of the molecular cascades which subserve lens development.
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| 3. |
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| 4. |
- Ferletta, Maria, et al.
(författare)
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Canine mammary tumors contain cancer stem-like cells and form spheroids with an embryonic stem cell signature
- 2011
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Ingår i: International Journal of Developmental Biology. - : UPV/EHU Press. - 0214-6282 .- 1696-3547. ; 55:7-9, s. 791-799
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the presence of tentative stem-like cells in the canine mammary tumor cell line CMT-U229. This cell line is established from an atypical benign mixed mammary tumor, which has the property of forming duct-like structures in collagen gels. Stem cells in mammary glands are located in the epithelium; therefore we thought that the CMT-U229 cell line would be suitable for detection of tentative cancer stem-like cells. Side population (SP) analyses by flow cytometry were performed with cells that formed spheroids and with cells that did not. Flow cytometric, single sorted cells were expanded and re-cultured as spheroids. The spheroids were paraffin embedded and characterized by immunohistochemistry. SP analyses showed that spheroid forming cells (retenate) as well as single cells (filtrate) contained SP cells. Sca1 positive cells were single cell sorted and thereafter the SP population increased with repeated SP analyses. The SP cells were positively labeled with the cell surface-markers CD44 and CD49f (integrin alpha6); however the expression of CD24 was low or negative. The spheroids expressed the transcription factor and stem cell marker Sox2, as well as Oct4. Interestingly, only peripheral cells of the spheroids and single cells were positive for Oct4 expression. SP cells are suggested to correspond to stem cells and in this study, we have enriched for tentative tumor stem-like cells derived from a canine mammary tumor. All the used markers indicate that the studied CMT-U229 cell line contains SP cells, which in particular have cancer stem-like cell characteristics.
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| 5. |
- Gustafsson, Renata, et al.
(författare)
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Expression of the novel gene Ened during mouse and Xenopus embryonic development.
- 2008
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Ingår i: International Journal of Developmental Biology. - : UPV/EHU Press. - 1696-3547 .- 0214-6282. ; 52:8, s. 1119-1122
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Tidskriftsartikel (refereegranskat)abstract
- We have recently identified 1110032E23Rik as a down-regulated target gene in Fgf receptor-signalling-deficient mouse embryoid bodies. Here, we present the expression pattern of this novel gene, designated Ened (Expressed in Nerve and Epithelium during Development), in mouse and Xenopus laevis embryos. Murine Ened transcripts were first seen at E9.5 in the heart and the gastrointestinal tract. At later stages of gestation, expression could be found in the floor plate, peripheral nervous system, lens epithelium, skin, midline dorsal aorta, lung, kidney and testis. In Xenopus, the expression of the Ened orthologue displayed common RNA distribution in several ectodermal and mesodermal tissues, but also distinct expression in locations including the brain, notochord and blood islands. We suggest that Ened might be a novel target gene of the Fgfr signalling pathway during embryonic development, and that its expression could be modulated by the basement membrane component laminin-111.
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| 6. |
- Hallböök, Finn, et al.
(författare)
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Distribution of BDNF and trkB mRNA in the otic region of 3.5 and 4.5 day chick embryos as revealed with a combination of in situ hybridization and tract tracing
- 1997
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Ingår i: International Journal of Developmental Biology. - 0214-6282 .- 1696-3547. ; 41:5, s. 725-732
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Tidskriftsartikel (refereegranskat)abstract
- We have used a recently developed technique which combines fluorescent tract tracing and in situ hybridization to study co-localization of neurotrophin mRNA and neurotrophin receptor mRNA expression simultaneously with the pattern of innervation in the developing chick ear. Efferent and afferent fibersfrom the VII/VIIIth cranial nerves were retrogradely and anterogradely filled with Dextran amines conjugated to Texas red and the brain stem was incubated for 2 hours in tissue culture medium. The tissue was subsequently fixed, sectioned frozen, mounted and subjected to in situ hybridization analysis using probes for brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor, trkB. The results show that afferent and efferent fibers to the ear innervate areas of the developing otocyst which express BDNF mRNA. We also found that neurons in the stato-acoustic ganglion express high levels of trkB mRNA whereas the subset of facial motor neurons that is efferent to the ear only had no or very low levels of trkB mRNA. From our results we conclude that chicken otic efferent fibers preferentially project to areas with BDNF mRNA expression. The very low levels of trkB mRNA in these motor neurons compared to afferent neurons innervating the same region suggest that other factors, perhaps co-expressed with BDNF, may support efferents. A possible involvement of afferents in guiding efferents to specific areas of the ear is suggested.
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| 7. |
- Hallböök, Finn, et al.
(författare)
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Neurotrophins and their receptors in chicken neuronal development
- 1995
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Ingår i: International Journal of Developmental Biology. - 0214-6282 .- 1696-3547. ; 39:5, s. 855-868
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Tidskriftsartikel (refereegranskat)abstract
- A review on current studies of chicken neurotrophins and their receptors is given. Chicken NGF, BDNF and NT-3 have been cloned and sequences have been used to synthesize oligonucleotides for specific localization of expression during development. Also, chicken TrkA, TrkB and TrkC have been cloned, sequenced and studied by in situ hybridization. Recombinant NT-3 was applied to chicken ganglia at different developmental stages to examine acquirement of responsiveness to NT-3 compared to NGF. Phylogenetic analyses of the chicken neurotrophins and Trk receptors were carried out based on parsimony. Finally, some data on apoptosis in chicken embryo sympathetic ganglia are presented.
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| 8. |
- Hermann-Kleiter, Natascha, et al.
(författare)
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Lasp1 misexpression influences chondrocyte differentiation in the vertebral column
- 2009
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Ingår i: International Journal of Developmental Biology. - : UPV/EHU Press. - 1696-3547 .- 0214-6282. ; 53:7, s. 983-991
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Tidskriftsartikel (refereegranskat)abstract
- The mouse mutant wavy tail Tg(Col1a1-lacZ)304ng was created through transgene insertion and exhibits defects of the vertebral column. Homozygous mutant animals have compressed tail vertebrae and wedge-shaped intervertebral discs, resulting in a meandering tail. Delayed closure of lumbar neural arches and lack of processus spinosi have been observed; these defects become most prominent during the transition from cartilage to bone. The spina bifida was resistant to folic acid treatment, while retinoic acid administration caused severe skeletal defects in the mutant, but none in wild type control animals. The transgene integrated at chromosome 11 band D, in an area of high gene density. The insertion site was located between the transcription start sites of the RpI23 and Lasp1 genes. LASP1 (an actin binding protein involved in cell migration and survival) was found to be produced in resting and hypertrophic chondrocytes in the vertebrae. In mutant vertebrae, temporal and spatial misexpression of Lasp1 was observed, indicating that alterations in Lasp1 transcription are most likely responsible for the observed phenotype. These data reveal a yet unappreciated role of Lasp1 in chondrocyte differentiation during cartilage to bone transition.
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| 9. |
- Ibáñez, C F, et al.
(författare)
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Expression of neurotrophin-4 mRNA during oogenesis in Xenopus laevis.
- 1992
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Ingår i: International Journal of Developmental Biology. - 0214-6282 .- 1696-3547. ; 36:2, s. 239-45
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Tidskriftsartikel (refereegranskat)abstract
- Neurotrophin-4 (NT-4), a recently discovered novel member of the family of neurotrophic factors structurally related to nerve growth factor (NGF), is abundantly expressed in the Xenopus laevis ovary. In this study we have localized NT-4 mRNA expressing cells in the Xenopus ovary by in situ hybridization and have used this technique together with Northern blot analyses to quantify NT-4 mRNA expression during oogenesis in Xenopus. In situ hybridization of sections through the Xenopus ovary using an alpha-[35S]-dATP labeled Xenopus NT-4 mRNA specific probe showed an intense labeling over the cytoplasm of oocytes with a diameter of 50-200 microns corresponding to stage I according to Dumont (1972). Labeling was also seen over the cytoplasm of stages II to IV although with a lower intensity than over stage I oocytes. No labeling was seen over more mature oocytes of stages V and VI. NT-4 mRNA could not be detected in the early embryo from the onset of cleavage division to the neurula stage suggesting that the NT-4 gene is not expressed during Xenopus early embryogenesis. The confinement of NT-4 mRNA in the Xenopus ovary to immature oocytes suggests that NT-4 mRNA expression is strictly regulated during oogenesis and that the NT-4 protein could play a role as a maturation factor for immature oocytes.
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| 10. |
- Janssen, Ralf
(författare)
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Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum
- 2014
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Ingår i: International Journal of Developmental Biology. - : UPV/EHU Press. - 0214-6282 .- 1696-3547. ; 58:5, s. 343-347
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Tidskriftsartikel (refereegranskat)abstract
- In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.
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