| 1. |
- Fagman, Henrik, 1975, et al.
(författare)
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The 22q11 deletion syndrome candidate gene Tbx1 determines thyroid size and positioning.
- 2007
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 16:3, s. 276-85
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Tidskriftsartikel (refereegranskat)abstract
- Thyroid dysgenesis is the major cause of congenital hypothyroidism in humans. The underlying molecular mechanism is in most cases unknown, but the frequent co-incidence of cardiac anomalies suggests that the thyroid morphogenetic process may depend on proper cardiovascular development. The T-box transcription factor TBX1, which is the most probable gene for the 22q11 deletion syndrome (22q11DS/DiGeorge syndrome/velo-cardio-facial syndrome), has emerged as a central player in the coordinated formation of organs and tissues derived from the pharyngeal apparatus and the adjacent secondary heart field from which the cardiac outflow tract derives. Here, we show that Tbx1 impacts greatly on the developing thyroid gland, although it cannot be detected in the thyroid primordium at any embryonic stage. Specifically, in Tbx1-/- mice, the downward translocation of Titf1/Nkx2.1-expressing thyroid progenitor cells is much delayed. In late mutant embryos, the thyroid fails to form symmetric lobes but persists as a single mass approximately one-fourth of the normal size. The hypoplastic gland mostly attains a unilateral position resembling thyroid hemiagenesis. The data further suggest that failure of the thyroid primordium to re-establish contact with the aortic sac is a key abnormality preventing normal growth of the midline anlage along the third pharyngeal arch arteries. In normal development, this interaction may be facilitated by Tbx1-expressing mesenchyme filling the gap between the pharyngeal endoderm and the detached thyroid primordium. The findings indicate that Tbx1 regulates intermediate steps of thyroid development by a non-cell-autonomous mechanism. Thyroid dysgenesis related to Tbx1 inactivation may explain an overrepresentation of hypothyroidism occurring in patients with the 22q11DS.
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| 2. |
- Smith, FJD, et al.
(författare)
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The genetic basis of pachyonychia congenita
- 2005
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Ingår i: The journal of investigative dermatology. Symposium proceedings. - : Elsevier BV. - 1087-0024. ; 10:1, s. 21-30
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Yang, T, et al.
(författare)
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Fe5O5[B6O10(OH)3]·nH2O: Wave-layered Iron Borate and Frustrated Antiferromagnetism
- 2009
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 48:23, s. 11209-11214
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Tidskriftsartikel (refereegranskat)abstract
- The first layered iron borate, Fe5O5[B6O10(OH)3]·nH2O, has been prepared by the boric acid flux method. Its structure, determined by single crystal X-ray diffraction, contains a double FeO6-octahedral layer and an unusual [B6O13] chain. The rigid and cambered [B6O13] chains bend the octahedral layers, resulting in a wave-like and sandwiched structure. Crystallographic study indicates the structural modulation is mainly from the [B6O13] chains because of the insertion of water molecules in between. Nevertheless, FeO6 layers in the average structure, which are well separated by borate chains, is still a reasonable model to understand the two-dimensional magnetism. The strong antiferromagnetic interactions and the complex Fe3+-net suggest a possible geometrically magnetic frustration, which may be the reason for the second-order temperature-induced magnetic transition at 125 K. The condensed Fe3+ layers and the relatively low redox potential at about 1.25 V versus Li+/Li show its potentials as an anodic material.
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