scholarly journals Generation of a new six1-null line in Xenopus tropicalis for study of development and congenital disease

2021 ◽  
Author(s):  
Kelsey Coppenrath ◽  
Andre Luiz Pasqua Tavares ◽  
Nikko-Ideen Shaidani ◽  
Marcin Wlizla ◽  
Sally A Moody ◽  
...  
Keyword(s):  
Target Genes ◽  
Branchial Arch ◽  
Xenopus Tropicalis ◽  
Mutant Line ◽  
Otic Vesicle ◽  
Null Line ◽  
Congenital Disease ◽  
Sine Oculis ◽  
Larval Stages ◽  
Cranial Ganglia

The vertebrate Six (Sine oculis homeobox) family of homeodomain transcription factors play critical roles in the development of several organs. Six1 plays a central role in cranial placode development, including the precursor tissues of the inner ear, as well as other cranial sensory organs and the kidney. In humans, mutations in SIX1 underlie some cases of branchio-oto-renal syndrome (BOR), which is characterized by moderate to severe hearing loss. We utilized CRISPR/Cas9 technology to establish a six1 mutant line in Xenopus tropicalis that is available to the research community. We demonstrate that at larval stages, the six1-null animals show severe disruptions in gene expression of putative Six1 target genes in the otic vesicle, cranial ganglia, branchial arch and neural tube. At tadpole stages, six1-null animals display dysmorphic Meckel's, ceratohyal and otic capsule cartilage morphology. This mutant line will be of value for the study of the development of several organs as well as congenital syndromes that involve these tissues.

Transformations Preserving Null Line Sections of a Domain: The Arbitrary Signature Case

1986 ◽  
Vol 9 (1-2) ◽  
pp. 107-118 ◽  
Author(s):  
J. A. Lester ◽  
J. A. Lester
Keyword(s):  
Null Line ◽  
Arbitrary Signature

scholarly journals Molecular basis for the CAT-2 null phenotype in maize.

Genetics ◽  
1988 ◽  
Vol 118 (1) ◽  
pp. 149-153
Author(s):  
L A Bethards ◽  
J G Scandalios
Keyword(s):  
Gene Expression ◽  
Molecular Basis ◽  
Protein Identification ◽  
Null Line ◽  
Maize Line ◽  
S1 Nuclease ◽  
Developmental Patterns ◽  
Catalase Gene ◽  
Null Phenotype ◽  
Rna Blots

Abstract Previous reports have described several maize lines whose developmental patterns of catalase gene expression vary from the "typical" maize line, W64A. Among these variants are the lines A16 and A338, both found to be null for the CAT-2 protein. Identification of a third CAT-2 null line, designated A340, is described. RNA blots and S1 nuclease protection analysis indicate that all three CAT-2 null lines produce a similarly shortened Cat2 transcript. The molecular basis for this aberrant Cat2 transcript is discussed.

scholarly journals Identification and molecular characterization of mutant line deficiency in three waxy proteins of common wheat (Triticum aestivum L.)

2019 ◽  
Author(s):  
Qian Liu ◽  
Yaping Hu ◽  
Mengyun Hu ◽  
Lijing Sun ◽  
Xiyong Chen ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Amylose Content ◽  
Premature Stop Codon ◽  
Triticum Aestivum L ◽  
Starch Granules ◽  
Null Line ◽  
Wild Type ◽  
Expression Levels ◽  
Waxy Proteins ◽  
Total Starch

Abstract Background: Starch is the main component of wheat (Triticum aestivum L.) grain and a key factor in determining wheat processing quality. The Wx gene encodes the granule bound starch synthase I (GBSS I) and is the sole gene responsible for amylose synthesis. Results: A waxy mutant (Wx-null) was isolated by screening M3 seeds derived from 1.0% EMS mutagenized materials with I2-KI staining of endosperm starch. SDS-PAGE electrophoresis confirmed that the Wx-null line lacked all three waxy proteins. DNA sequencing revealed three SNPs and a 3-bp InDel in the first exon, and a 16-bp InDel at the junction region of the first Wx-A1 intron from the Wx-null line. Six SNPs were identified in Wx-B1 gene of Wx-null line compared to the wild-type Gao 8901, including four missense mutations. One nonsense mutation was found at position 857 in the fourth exon, which resulted in a premature stop codon. Expression levels of Wx genes were dramatically reduced in the Wx-null line. Nonsense-mediated mRNA decay (NMD) may be triggered to degrade the non-functional Wx mRNA. There were no detectable differences in granule size and morphology between Wx-null and wild-type, but the Wx-null line contained a larger proportion of B-type starch granules. The amylose content of the Wx-null line (0.22%) was remarkably lower compared to the wild-type Gao 8901 (20.82%). Total starch is also lower in the Wx-null line. Conclusions: All three waxy proteins were non-functional in the Wx-null line. NMD may be the cause for reduced expression levels of Wx genes in the Wx-null line. The Wx-null line exhibited more B-type starch granules, dramatically lower amylose content, and decreased total starch. The Wx-null line may provide a potential waxy material with high agronomic performance in wheat breeding programs.

scholarly journals ON THE MASS NEUTRINO PHASE ALONG THE GEODESIC LINE AND THE NULL LINE IN CURVED AND FLAT SPACETIME

2003 ◽  
Vol 12 (04) ◽  
pp. 727-738 ◽  
Author(s):  
C. M. ZHANG ◽  
A. BEESHAM
Keyword(s):  
Physical Process ◽  
Double Counting ◽  
Null Line ◽  
Geodesic Line ◽  
Curved Spacetime ◽  
Flat Spacetime ◽  
Phase Calculation ◽  
Real Physical Process

On the mass neutrino phase calculations along both the particle geodesic line and the photon null line, there exists a double counting, a factor of 2, when comparing the geodesic phase with the null phase. Moreover, we compare the phase calculations with the same-energy description and the same-momentum description by means of the Minkowski diagram, and obtain the practical equivalence of these two descriptions. On the same-velocity description, although not corresponding any real physical process, we still indicate its phase calculation in the Minkowski diagram, which has the same result as those of same-energy and same-momentum cases. Furthermore, in the curved spacetime, we also prove the existence of the double counting of the geodesic phase to the null phase. Our conclusions are the same as others' results by the different methods.

scholarly journals Research on Self-potential Base Line Drift Processing in Wangji Oilfield

2015 ◽  
Vol 5 (2) ◽  
pp. 30
Author(s):  
Hong Fang
Keyword(s):  
Computer Technology ◽  
Stratigraphic Correlation ◽  
Base Line ◽  
Null Line ◽  
Differential Migration ◽  
Font Size ◽  
Scale Range ◽  
Self Potential ◽  
Geological Research ◽  
Potential Curves

<span style="font-family: &quot;Times New Roman&quot;,&quot;serif&quot;; font-size: 10pt; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;" lang="EN-US">The positive amplitude anomalies and base line drifts of self-potential (SP) curves make it difficult to recognize the amplitude anomalies and impossible to carry on the standardized calibration. In this way, it becomes extremely hard to read the amplitude anomalies of self-potential curves, increasing the difficulty in lithology recognition and stratigraphic correlation. What’s more, it is impossible to apply the computer technology to do the batch processing. Aimed at the practical problems, taking advantages of the collected digital logging data, positive self-potential anomaly recognition and transformation models have been established, converting the positive anomalies in the sandstone intervals into negative ones, solving the problem of two types of amplitude anomalies in the same scale range. Self-potential base line drift processing moves the biased base line to the null line step by step, adopting the method of piecewise fitting differential migration. With satisfying results, the conformation, amplitude and jugged degree are accordant with the primary curve, forming the technique of self-potential curve processing, laying foundation for logging translation and geological research.</span>

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