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Zinc (Zn) deficiency in animals became of interest until the 1950s. In this paper, progresses in researches on physiology of Zn deficiency in animals, phytate effect on bioavailability of Zn, and role of phytase in healing Zn deficiency of animals were reviewed. Several studies demonstrated that Zn is recycled via the pancreas; the problem of Zn deficiency was controlled by Zn homeostasis. The endogenous secretion of Zn is considered as an important factor influencing Zn deficiency, and the critical molar ratio is 10. Phytate (inositol hexaphosphate) constituted up to 90% of the organically bound phosphorus in seeds. Great improvement has been made in recent years on isolating and measuring phytate, and its structure is clear. Phytate is considered to reduce Zn bioavailability in animal. Phytase is the enzyme that hydrolyzes phytate and is present in yeast, rye bran, wheat bran, barley, triticale, and many bacteria and fungi. Zinc nutrition and bioavailability can be enhanced by addition of phytase to animal feeds. Therefore, using phytase as supplements, the most prevalent Zn deficiency in animals may be effectively corrected without the mining and smelting of several tons of zinc daily needed to correct this deficiency by fortification worldwide.  相似文献   
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The BMP antagonist noggin regulates cranial suture fusion   总被引:11,自引:0,他引:11  
During skull development, the cranial connective tissue framework undergoes intramembranous ossification to form skull bones (calvaria). As the calvarial bones advance to envelop the brain, fibrous sutures form between the calvarial plates. Expansion of the brain is coupled with calvarial growth through a series of tissue interactions within the cranial suture complex. Craniosynostosis, or premature cranial suture fusion, results in an abnormal skull shape, blindness and mental retardation. Recent studies have demonstrated that gain-of-function mutations in fibroblast growth factor receptors (fgfr) are associated with syndromic forms of craniosynostosis. Noggin, an antagonist of bone morphogenetic proteins (BMPs), is required for embryonic neural tube, somites and skeleton patterning. Here we show that noggin is expressed postnatally in the suture mesenchyme of patent, but not fusing, cranial sutures, and that noggin expression is suppressed by FGF2 and syndromic fgfr signalling. Since noggin misexpression prevents cranial suture fusion in vitro and in vivo, we suggest that syndromic fgfr-mediated craniosynostoses may be the result of inappropriate downregulation of noggin expression.  相似文献   
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During limb outgrowth, signaling by bone morphogenetic proteins (BMPs) must be moderated to maintain the signaling loop between the zone of polarizing activity (ZPA) and the apical ectodermal ridge (AER). Gremlin, an extracellular Bmp antagonist, has been proposed to fulfill this function and therefore be important in limb patterning. We tested this model directly by mutating the mouse gene encoding gremlin (Cktsf1b1, herein called gremlin). In the mutant limb, the feedback loop between the ZPA and the AER is interrupted, resulting in abnormal skeletal pattern. We also show that the gremlin mutation is allelic to the limb deformity mutation (ld). Although Bmps and their antagonists have multiple roles in limb development, these experiments show that gremlin is the principal BMP antagonist required for early limb outgrowth and patterning.  相似文献   
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Dishevelled controls cell polarity during Xenopus gastrulation   总被引:11,自引:0,他引:11  
Although cell movements are vital for establishing the normal architecture of embryos, it is unclear how these movements are regulated during development in vertebrates. Inhibition of Xenopus Dishevelled (Xdsh) function disrupts convergent extension movements of cells during gastrulation, but the mechanism of this effect is unclear, as cell fates are not affected. In Drosophila, Dishevelled controls both cell fate and cell polarity, but whether Dishevelled is involved in controlling cell polarity in vertebrate embryos has not been investigated. Here we show, using time-lapse confocal microscopy, that the failure of cells lacking Xdsh function to undergo convergent extension results from defects in cell polarity. Furthermore, Xdsh mutations that inhibit convergent extension correspond to mutations in Drosophila Dishevelled that selectively perturb planar cell polarity. Finally, the localization of Xdsh at the membrane of normal dorsal mesodermal cells is consistent with Xdsh controlling cell polarity. Our results show that polarized cell behaviour is essential for convergent extension and is controlled by vertebrate Dishevelled. Thus, a vertebrate equivalent of the Drosophila planar cell polarity signalling cascade may be required for normal gastrulation.  相似文献   
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To make full use of research data, the bioscience community needs to adopt technologies and reward mechanisms that support interoperability and promote the growth of an open 'data commoning' culture. Here we describe the prerequisites for data commoning and present an established and growing ecosystem of solutions using the shared 'Investigation-Study-Assay' framework to support that vision.  相似文献   
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We report a genome-wide association study for melanoma that was conducted by the GenoMEL Consortium. Our discovery phase included 2,981 individuals with melanoma and 1,982 study-specific control individuals of European ancestry, as well as an additional 6,426 control subjects from French or British populations, all of whom were genotyped for 317,000 or 610,000 single-nucleotide polymorphisms (SNPs). Our analysis replicated previously known melanoma susceptibility loci. Seven new regions with at least one SNP with P < 10(-5) and further local imputed or genotyped support were selected for replication using two other genome-wide studies (from Australia and Texas, USA). Additional replication came from case-control series from the UK and The Netherlands. Variants at three of the seven loci replicated at P < 10(-3): an SNP in ATM (rs1801516, overall P = 3.4 × 10(-9)), an SNP in MX2 (rs45430, P = 2.9 × 10(-9)) and an SNP adjacent to CASP8 (rs13016963, P = 8.6 × 10(-10)). A fourth locus near CCND1 remains of potential interest, showing suggestive but inconclusive evidence of replication (rs1485993, overall P = 4.6 × 10(-7) under a fixed-effects model and P = 1.2 × 10(-3) under a random-effects model). These newly associated variants showed no association with nevus or pigmentation phenotypes in a large British case-control series.  相似文献   
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Recently, two common sequence variants on 9p21, tagged by rs10757278-G and rs10811661-T, were reported to be associated with coronary artery disease (CAD) and type 2 diabetes (T2D), respectively. We proceeded to further investigate the contributions of these variants to arterial diseases and T2D. Here we report that rs10757278-G is associated with, in addition to CAD, abdominal aortic aneurysm (AAA; odds ratio (OR) = 1.31, P = 1.2 x 10(-12)) and intracranial aneurysm (OR = 1.29, P = 2.5 x 10(-6)), but not with T2D. This variant is the first to be described that affects the risk of AAA and intracranial aneurysm in many populations. The association of rs10811661-T to T2D replicates in our samples, but the variant does not associate with any of the five arterial diseases examined. These findings extend our insight into the role of the sequence variant tagged by rs10757278-G and show that it is not confined to atherosclerotic diseases.  相似文献   
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