slimb coordinates wg and dpp expression in the dorsal-ventral and anterior-posterior axes during limb development

Development ◽  
1998 ◽  
Vol 125 (17) ◽  
pp. 3411-3416 ◽  
Author(s):  
N.A. Theodosiou ◽  
S. Zhang ◽  
W.Y. Wang ◽  
T. Xu
Keyword(s):  
Genetic Analysis ◽  
Limb Development ◽  
Imaginal Disc ◽  
Essential Role ◽  
Present Evidence ◽  
First Time ◽  
Anterior Posterior

In the Drosophila leg disc, wingless (wg) and decapentaplegic (dpp) are expressed in a ventral-anterior and dorsal-anterior stripe of cells, respectively. This pattern of expression is essential for proper limb development. While the Hedgehog (Hh) pathway regulates dpp and wg expression in the anterior-posterior (A/P) axis, mechanisms specifying their expression in the dorsal-ventral (D/V) axis are not well understood. We present evidence that slimb mutant clones in the disc deregulate wg and dpp expression in the D/V axis. This suggests for the first time that their expression in the D/V axis is actively regulated during imaginal disc development. Furthermore, slimb is unique in that it also deregulates wg and dpp in the A/P axis. The misexpression phenotypes of slimb- clones indicate that the regulation of wg and dpp expression is coordinated in both axes, and that slimb plays an essential role in integrating A/P and D/V signals for proper patterning during development. Our genetic analysis further reveals that slimb intersects the A/P pathway upstream of smoothened (smo).

Dpp receptor levels contribute to shaping the Dpp morphogen gradient in the Drosophila wing imaginal disc

Development ◽  
1998 ◽  
Vol 125 (24) ◽  
pp. 4901-4907 ◽  
Author(s):  
T. Lecuit ◽  
S.M. Cohen
Keyword(s):  
Imaginal Disc ◽  
Wing Imaginal Disc ◽  
Morphogen Gradient ◽  
Axis Formation ◽  
Present Evidence ◽  
Drosophila Wing ◽  
Spatial Domains ◽  
Low Levels ◽  
Wing Pouch ◽  
Anterior Posterior

Axis formation in the Drosophila wing depends on the localized expression of the secreted signaling molecule Decapentaplegic (Dpp). Dpp acts directly at a distance to specify discrete spatial domains, suggesting that it functions as a morphogen. Expression levels of the Dpp receptor thick veins (tkv) are not uniform along the anterior-posterior axis of the wing imaginal disc. Receptor levels are low where Dpp induces its targets Spalt and Omb in the wing pouch. Receptor levels increase in cells farther from the source of Dpp in the lateral regions of the disc. We present evidence that Dpp signaling negatively regulates tkv expression and that the level of receptor influences the effective range of the Dpp gradient. High levels of tkv sensitize cells to low levels of Dpp and also appear to limit the movement of Dpp outside the wing pouch. Thus receptor levels help to shape the Dpp gradient.

scholarly journals Central precocious puberty in a girl with LEGIUS syndrome: an accidental association?

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Valentina Orlandi ◽  
Paolo Cavarzere ◽  
Laura Palma ◽  
Rossella Gaudino ◽  
Franco Antoniazzi
Keyword(s):  
Genetic Analysis ◽  
Precocious Puberty ◽  
Central Precocious Puberty ◽  
Neurofibromatosis Type ◽  
Case Presentation ◽  
New Variant ◽  
Legius Syndrome ◽  
Timing Of Puberty ◽  
First Time

Abstract Background Central precocious puberty is a condition characterized by precocious activation of the hypothalamic-pituitary-gonadal axis. It may be idiopathic or secondary to organic causes, including syndromes such as Neurofibromatosis type 1 (NF1). Case presentation We presented a girl of 6 years and 10 months with almost 11 café-au-lait skin macules, without other clinical or radiological signs typical of NF1, and with a central precocious puberty. Genetic analysis evidenced the new variant NM-152594.2:c.304delAp. (Thr102Argfs*19) in SPRED1 gene, which allowed to diagnose Legius syndrome. Conclusions We report for the first time a case of central precocious puberty in a girl with Legius syndrome. The presence of central precocious puberty in a child with characteristic café-au-lait macules should suggest pediatricians to perform genetic analysis in order to reach a definitive diagnosis. Further studies on timing of puberty in patients with RASopathies are needed to better elucidate if this clinical association is casual or secondary to their clinical condition.

Neural Correlates of Mathematical Problem Solving

2015 ◽  
Vol 25 (02) ◽  
pp. 1550004 ◽  
Author(s):  
Chun-Ling Lin ◽  
Melody Jung ◽  
Ying Choon Wu ◽  
Hsiao-Ching She ◽  
Tzyy-Ping Jung
Keyword(s):  
Problem Solving ◽  
Spectral Power ◽  
Mathematical Problem ◽  
Neural Correlates ◽  
Mathematical Problem Solving ◽  
Single Digit ◽  
Beta Power ◽  
First Time ◽  
Anterior Posterior ◽  
Arithmetical Problem Solving

This study explores electroencephalography (EEG) brain dynamics associated with mathematical problem solving. EEG and solution latencies (SLs) were recorded as 11 neurologically healthy volunteers worked on intellectually challenging math puzzles that involved combining four single-digit numbers through basic arithmetic operators (addition, subtraction, division, multiplication) to create an arithmetic expression equaling 24. Estimates of EEG spectral power were computed in three frequency bands — θ (4–7 Hz), α (8–13 Hz) and β (14–30 Hz) — over a widely distributed montage of scalp electrode sites. The magnitude of power estimates was found to change in a linear fashion with SLs — that is, relative to a base of power spectrum, theta power increased with longer SLs, while alpha and beta power tended to decrease. Further, the topographic distribution of spectral fluctuations was characterized by more pronounced asymmetries along the left–right and anterior–posterior axes for solutions that involved a longer search phase. These findings reveal for the first time the topography and dynamics of EEG spectral activities important for sustained solution search during arithmetical problem solving.

Role of knot (kn) in Wing Patterning in Drosophila

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1203-1212 ◽  
Author(s):  
Katerina Nestoras ◽  
Helena Lee ◽  
Jym Mohler
Keyword(s):  
Hedgehog Signaling ◽  
Imaginal Disc ◽  
Hedgehog Signaling Pathway ◽  
Posterior Compartment ◽  
Drosophila Wing ◽  
Compartment Boundary ◽  
Hh Signaling ◽  
Embryonic Segmentation ◽  
Anterior Posterior

We have undertaken a genetic analysis of new strong alleles of knot (kn). The original kn1 mutation causes an alteration of wing patterning similar to that associated with mutations of fused (fu), an apparent fusion of veins 3 and 4 in the wing. However, unlike fu, strong kn mutations do not affect embryonic segmentation and indicate that kn is not a component of a general Hh (Hedgehog)-signaling pathway. Instead we find that kn has a specific role in those cells of the wing imaginal disc that are subject to ptc-mediated Hh-signaling. Our results suggest a model for patterning the medial portion of the Drosophila wing, whereby the separation of veins 3 and 4 is maintained by kn activation in the intervening region in response to Hh-signaling across the adjacent anterior-posterior compartment boundary.

Mutation of OsCAX1a Results in Panicle Degeneration in Rice

2021 ◽  
Author(s):  
Quan Gan ◽  
Fengshun Song ◽  
Cuixiang Lin ◽  
Dahu Ni
Keyword(s):  
Protein Sequence ◽  
Essential Role ◽  
Cereal Crops ◽  
View Point ◽  
Mutation Site ◽  
Protein Sequence Alignment ◽  
Qrt Pcr ◽  
Panicle Development ◽  
Motif Identification ◽  
First Time

Abstract Background: Rice is one of the most common cereal crops in China. Increasing the yield of rice has always been a primary purpose of rice breeding. However, panicle degeneration in rice, a complex characteristic regulated by many genes and commonly encountered in rice production, seriously reduces the yield. Findings: In this study, we obtained a new apical panicle degeneration mutant named ym48, which exhibits a serious degeneration rate and reduced grain yield in rice. After fine mapping, the OsCAX1a gene responsible for Ca2+ selection and transportation was identified. In the ym48 mutant of the OsCAX1a gene, a A to G substitution was noted at the 190th nucleotide, and the corresponding 64th amino acid was changed from threonine to alanine. Also, the tolerance from Ca2+ stress was damaged due to the mutation. Phylogenetics, protein sequence alignment and motif identification of CAX family members in Arabidopsis and rice indicated that this mutation site was highly conserved and might play an essential role in Ca2+ transportation. Moreover, the OsCAX1a expression pattern was analyzed in rice. qRT-PCR and GUS (β-glucuronidase) staining experiments showed that OsCAX1a was highly expressed in roots, stems and panicles and that its expression increased with panicle development. Conclusions: These results demonstrated that OsCAX1a played an essential role in the regulation of panicle development for the first time and mutation of OsCAX1a would generate the panicle degeneration in rice. This study provided a new view point to explore the mechanism of panicle development and degeneration in rice.

scholarly journals Essential roles for Pot1b in HSC self-renewal and survival

Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6068-6077 ◽  
Author(s):  
Yang Wang ◽  
Mei-Feng Shen ◽  
Sandy Chang
Keyword(s):  
Progenitor Cell ◽  
Essential Role ◽  
Dyskeratosis Congenita ◽  
Telomere Maintenance ◽  
Wild Type ◽  
Telomere Shortening ◽  
Damage Response ◽  
First Time

Abstract Maintenance of mammalian telomeres requires both the enzyme telomerase and shelterin, which protect telomeres from inappropriately activating DNA damage response checkpoints. Dyskeratosis congenita is an inherited BM failure syndrome disorder because of defects in telomere maintenance. We have previously shown that deletion of the shelterin component Pot1b in the setting of telomerase haploinsufficiency results in rapid telomere shortening and fatal BM failure in mice, eliciting phenotypes that strongly resemble human syskeratosis congenita. However, it was unclear why BM failure occurred in the setting of Pot1b deletion. In this study, we show that Pot1b plays an essential role in HSC survival. Deletion of Pot1b results in increased apoptosis, leading to severe depletion of the HSC reserve. BM from Pot1bΔ/Δ mice cannot compete with BM from wild-type mice to provide multilineage reconstitution, indicating that there is an intrinsic requirement for Pot1b the maintenance of HSC function in vivo. Elimination of the p53-dependent apoptotic function increased HSC survival and significantly extended the lifespan of Pot1b-null mice deficient in telomerase function. Our results document for the first time the essential role of a component of the shelterin complex in the maintenance of HSC and progenitor cell survival.

Quantitative Genetics of Drosophila Melanogaster. II. Heritabilities and Genetic Correlations between Sexes for Head and Thorax Traits.

Genetics ◽  
1988 ◽  
Vol 119 (2) ◽  
pp. 421-433
Author(s):  
D E Cowley ◽  
W R Atchley
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
X Chromosome ◽  
Dosage Compensation ◽  
Imaginal Disc ◽  
Genetic Correlations ◽  
Body Parts ◽  
Quantitative Genetic ◽  
Males And Females

Abstract A quantitative genetic analysis is reported for traits on the head and thorax of adult fruit flies, Drosophila melanogaster. Females are larger than males, and the magnitude of sexual dimorphism is similar for traits derived from the same imaginal disc, but the level of sexual dimorphism varies widely across discs. The greatest difference between males and females occurs for the dimensions of the sclerotized mouthparts of the proboscis. Most of the traits studied are highly heritable with heritabilities ranging from 0.26 to 0.84 for males and 0.27 to 0.81 for females. In general, heritabilities are slightly higher for males, possibly reflecting the effect of dosage compensation on X-linked variance. The X chromosome contributes substantially to variance for many of these traits, and including results reported elsewhere, the variance for over two-thirds of the traits studied includes X-linked variance. The genetic correlations between sexes for the same trait are generally high and close to unity. Coupled with the small differences in the traits between sexes for heritabilities and phenotypic variances, these results suggest that selection would be very slow to change the level of sexual dimorphism in size of various body parts.

scholarly journals Twist Plays an Essential Role in FGF and SHH Signal Transduction during Mouse Limb Development

2002 ◽  
Vol 248 (1) ◽  
pp. 143-156 ◽  
Author(s):  
Meredith P. O'Rourke ◽  
Kenneth Soo ◽  
Richard R. Behringer ◽  
Chi-Chung Hui ◽  
Patrick P.L. Tam
Keyword(s):  
Signal Transduction ◽  
Limb Development ◽  
Essential Role ◽  
Mouse Limb

scholarly journals Cleavage of membrane-associated pref-1 generates a soluble inhibitor of adipocyte differentiation.

1997 ◽  
Vol 17 (2) ◽  
pp. 977-988 ◽  
Author(s):  
C M Smas ◽  
L Chen ◽  
H S Sul
Keyword(s):  
Adipocyte Differentiation ◽  
Constitutive Expression ◽  
Soluble Form ◽  
Inhibitory Effects ◽  
Alternate Splicing ◽  
Produce Cell ◽  
Present Evidence ◽  
Juxtamembrane Region ◽  
Epidermal Growth ◽  
First Time

pref-1 is an epidermal growth factor-like repeat protein present on the surface of preadipocytes that functions in the maintenance of the preadipose state. pref-1 expression is completely abolished during 3T3-L1 adipocyte differentiation. Bypassing this downregulation by constitutive expression of full-length transmembrane pref-1 in preadipocytes drastically inhibits differentiation. For the first time, we show processing of cell-associated pref-1 to generate both a soluble pref-1 protein of approximately 50 kDa that corresponds to the ectodomain and also smaller products of 24 to 25 kDa and 31 kDa. Furthermore, while all four of the alternately spliced forms of pref-1 produce cell-associated protein, only the two largest of the four alternately spliced isoforms undergo cleavage in the juxtamembrane region to release the soluble 50-kDa ectodomain. We demonstrate that addition of Escherichia coli-expressed pref-1 ectodomain to 3T3-L1 preadipocytes blocks differentiation, thus overriding the adipogenic actions of dexamethasone and methylisobutylxanthine. The inhibitory effects of the pref-1 ectodomain are blocked by preincubation of the protein with pref-1 antibody. That the ectodomain alone is sufficient for inhibition demonstrates that transmembrane pref-1 can be processed to generate an inhibitory soluble form, thereby greatly extending its range of action. Furthermore, we present evidence that alternate splicing is the mechanism that governs the production of transmembrane versus soluble pref-1, thereby determining the mode of action, juxtacrine or paracrine, of the pref-1 protein.

Dinoflagellate cyst distribution around the British Isles

1972 ◽  
Vol 52 (4) ◽  
pp. 939-944 ◽  
Author(s):  
Philip C. Reid
Keyword(s):  
Red Tide ◽  
Irish Sea ◽  
Intertidal Sediment ◽  
British Isles ◽  
Present Evidence ◽  
Gonyaulax Polyedra ◽  
Large Numbers ◽  
First Time ◽  
Potential Conditions ◽  
Motile Stage

Rich assemblages of acid-resistant microfossils occur in intertidal sediment from the British Isles and are here reported, for the first time, to contain large numbers of dino-flagellate cysts. These cysts provide evidence to show that the distribution of certain dino-flagellate cysts is different from that of the motile stage, that the coastal distribution of cysts appears to be controlled by currents and that their occurrence within bays is possibly related to localized temperature and salinity conditions. Further, they present evidence that potential conditions for a red tide of Gonyaulax polyedra Stein may be present in the east Irish Sea.

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