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11.
Emily K. Mis Karel F. Liem Jr. Yong Kong Nancy B. Schwartz Miriam Domowicz Scott D. Weatherbee 《Developmental biology》2014
The long bones of the vertebrate body are built by the initial formation of a cartilage template that is later replaced by mineralized bone. The proliferation and maturation of the skeletal precursor cells (chondrocytes) within the cartilage template and their replacement by bone is a highly coordinated process which, if misregulated, can lead to a number of defects including dwarfism and other skeletal deformities. This is exemplified by the fact that abnormal bone development is one of the most common types of human birth defects. Yet, many of the factors that initiate and regulate chondrocyte maturation are not known. We identified a recessive dwarf mouse mutant (pug) from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. pug mutant skeletal elements are patterned normally during development, but display a ~20% length reduction compared to wild-type embryos. We show that the pug mutation does not lead to changes in chondrocyte proliferation but instead promotes premature maturation and early ossification, which ultimately leads to disproportionate dwarfism. Using sequence capture and high-throughput sequencing, we identified a missense mutation in the Xylosyltransferase 1 (Xylt1) gene in pug mutants. Xylosyltransferases catalyze the initial step in glycosaminoglycan (GAG) chain addition to proteoglycan core proteins, and these modifications are essential for normal proteoglycan function. We show that the pug mutation disrupts Xylt1 activity and subcellular localization, leading to a reduction in GAG chains in pug mutants. The pug mutant serves as a novel model for mammalian dwarfism and identifies a key role for proteoglycan modification in the initiation of chondrocyte maturation. 相似文献
12.
J. Plaschke A. Börner D. X. Xie R. M. D. Koebner R. Schlegel M. D. Gale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,85(8):1049-1054
Summary RFLP mapping of chromosome 5R in the F3 generation of a rye (Secale cereale L.) cross segregating for gibberellic acid (GA3)-insensitive dwarfness (Ct2/ct2) and spring growth habit (Sp1/sp1) identified RFLP loci close to each of these agronomically important genes. The level of RFLP in the segregating population was high, and thus allowed more than half of the RFLP loci to be mapped, despite partial homozygosity in the parental F2 plant. Eight further loci were mapped in an unrelated F2 rye population, and a further two were placed by inference from equivalent genetic maps of related wheat chromosomes, allowing a consensus map of rye chromosome 5R, consisting of 29 points and spanning 129 cM, to be constructed. The location of the ct2 dwarfing gene was shown to be separated from the segment of the primitive 4RL translocated to 5RL, and thus the gene is probably genetically unrelated to the major GA-insensitive Rht genes of wheat located on chromosome arms 4BS and 4DS. The map position of Sp1 is consistent both with those of wheat Vrn1 and Vrn3, present on chromosome arms 5AL and 5DL, respectively, and with barley Sh2 which is distally located on chromosome arm 7L (= 5HL). 相似文献
13.
J. E. Flintham M. D. Gale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,62(2):121-126
Summary The effects of the Tom Thumb dwarfing gene, Rht3, on the quality and quantity of grain -amylase produced during germination and by induction with exogenous gibberellic acid are described. In a season conducive to high sprouting damage the gene reduced -amylase levels in the field by 77%. Selection among random Rht3 genotypes showed that other genetic factors can be combined with the dwarfing gene to further increase sprouting damage resistance. 相似文献
14.
Muhammad Imran Naseer Angham Abdulrahman Abdulkareem Osama Yousef Muthaffar Adeel G. Chaudhary 《Saudi Journal of Biological Sciences》2021,28(5):2824-2829
RTTN (Rotatin) (OMIM 614833) is a large centrosomal protein coding gene. RTTN mutations are responsible for syndromic forms of malformation of brain development, leading to polymicrogyria, microcephaly, primordial dwarfism, seizure along with many other malformations. In this study we have identified a compound heterozygous mutation in RTTN gene having NM_173630 c.5225A > G p.His1742Arg in exon 39 and NM_173630 c.6038G > T p.Cys2013Phe in exon 45 of a consanguineous Saudi family leading to brain malformation, seizure, developmental delay, dysmorphic feature and microcephaly. Whole exome sequencing (WES) techniques was used to identify the causative mutation in the affected members of the family. WES data analysis was done and obtained data were further confirmed by using Sanger sequencing analysis. Moreover, the mutation was ruled out in 100 healthy control from normal population. To the best of our knowledge the novel compound heterozygous mutation observed in this study is the first report from Saudi Arabia. The identified compound heterozygous mutation will further explain the role of RTTN gene in development of microcephaly and neurodevelopmental disorders. 相似文献
15.
The taxonomic status of the small bodied hominin, Homo floresiensis, remains controversial. One contentious aspect of the debate concerns the small brain size estimated for specimen LB1 (Liang Bua 1). Based on intraspecific mammalian allometric relationships between brain and body size, it has been argued that the brain of LB1 is too small for its body mass and is therefore likely to be pathological. The relevance and general applicability of these scaling rules has, however, been challenged, and it is not known whether highly encephalized primates adapt to insular habitats in a consistent manner. Here, an analysis of brain and body size evolution in seven extant insular primates reveals that although insular primates follow the ‘island rule’, having consistently reduced body masses compared with their mainland relatives, neither brain mass nor relative brain size follow similar patterns, contrary to expectations that energetic constraints will favour decreased relative brain size. Brain:body scaling relationships previously used to assess the plausibility of dwarfism in H. floresiensis tend to underestimate body masses of insular primates. In contrast, under a number of phylogenetic scenarios, the evolution of brain and body mass in H. floresiensis is consistent with patterns observed in other insular primates. 相似文献
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17.
Variations in the content of A-2α and β, novel endogenous growth inhibitors, andcis,trans- andtrans, trans-xanthoxins were determined in 6- or 7-d-old, dark-grown seedlings of peas (Pisum sativum L. cvs. Progress No. 9, dwarf, and Alaska, tall) under various treatments with red light (R), and compared with R-induced
growth inhibition. After transfer of the plants to continuous R the contents of the A-2s in cv. Progress increased after a
20-min lag, and reached plateaus after 12 h, whereas they remained almost unchanged in darkness. Both the rates of increase
of the A-2s and the plateau levels were proportional to the logarithm of the irradiance applied. After a 10-min R pulse, the
contents of both A-2α and β increased with the same rapidity to reach peaks after 6 h, and then gradually decreased to the
initial levels after about 24 h. The effect of R was shown to be phytochrome-dependent, being nullified by far-red light.
The level of neithercis,trans- nortrans,trans-xanthoxin showed such a close correlation with growth inhibition, although both xanthoxins increased as a result of phytochrome
action. It is highly suggestive that the A-2s, rather than the xanthoxins, are responsible for phytochrome-dependent growth
inhibition in cv. Progress. In cv. Alaska, in contrast, R-induced increase of the A-2s was rapid but slight, and could not
explain the transient growth inhibition, which was found to be as large as that in cv. Progress shortly after the onset of
R. The large content of the A-2s in cv. Progress in the steady state under continuous R, compared with that in cv. Alaska,
may explain the dwarfism of cv. Progress.
Dedicated to Professor Hans Mohr on the occasion of his 60th birthday 相似文献
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19.
Dalmadi A Kaló P Jakab J Saskoi A Petrovics T Deák G Kiss GB 《Plant cell reports》2008,27(8):1271-1279
In this paper we describe the identification of a gene, MsDWF1 coding for a putative gibberellin 3-beta-hydroxylase (GA3ox), whose natural mutation is conditioning a dwarf growth phenotype in Medicago sativa. The dwarf phenotype could not be complemented with grafting, which indicates that the bioactive gibberellin compound necessary for shoot elongation is immobile. On the contrary, exogenously added gibberellic acid restored normal growth. The genetic position of the Msdwf1 gene was mapped to linkage group 2 (LG2) and the physical location was delimited by map-based cloning using Medicago truncatula genomic resources. Based on the similar appearance and behavior of the dwarf Medicago sativa plants to the pea stem length mutant (le) as well as the synthenic map position of the two genes it was postulated that MsDWF1 and pea Le are orthologs. The comparison of wild type and mutant allele sequences of MsGA3ox revealed an amino acid change in a conserved position in the mutant allele, which most probably impaired the function of the enzyme. Our results indicate that the dwarf phenotype was the consequence of this mutation. 相似文献
20.
Dijkstra C Adams E Bhattacharya A Page AF Anthony P Kourmpetli S Power JB Lowe KC Thomas SG Hedden P Phillips AL Davey MR 《Plant cell reports》2008,27(3):463-470
Gibberellins (GAs) are endogenous hormones that play a predominant role in regulating plant stature by increasing cell division
and elongation in stem internodes. The product of the GA 2-oxidase gene from Phaseolus coccineus (PcGA2ox1) inactivates C19-GAs, including the bioactive GAs GA1 and GA4, by 2β-hydroxylation, reducing the availability of these GAs in plants. The PcGA2ox1 gene was introduced into Solanum melanocerasum and S. nigrum (Solanaceae) by Agrobacterium-mediated transformation with the aim of decreasing the amounts of bioactive GA in these plants and thereby reducing their
stature. The transgenic plants exhibited a range of dwarf phenotypes associated with a severe reduction in the concentrations
of the biologically active GA1 and GA4. Flowering and fruit development were unaffected. The transgenic plants contained greater concentrations of chlorophyll b (by 88%) and total chlorophyll (11%), although chlorophyll a and carotenoid contents were reduced by 8 and 50%, respectively. This approach may provide an alternative to the application
of chemical growth retardants for reducing the stature of plants, particularly ornamentals, in view of concerns over the potential
environmental and health hazards of such compounds.
C. Dijkstra, E. Adams, A. Bhattacharya and A. F. Page contributed equally to this paper. 相似文献