Generation of pigmented stripes in albino mice by retroviral marking of neural crest melanoblasts

Development ◽  
1991 ◽  
Vol 113 (2) ◽  
pp. 653-660 ◽  
Author(s):  
D. Huszar ◽  
A. Sharpe ◽  
S. Hashmi ◽  
B. Bouchard ◽  
A. Houghton ◽  
...  
Keyword(s):  
Neural Crest ◽  
Retroviral Vector ◽  
Mouse Embryos ◽  
Pigment Cells ◽  
Wild Type ◽  
Tyrosinase Gene ◽  
History Of ◽  
Albino Mice ◽  
Type Gene ◽  
Dual Origin

The pigment cells of the skin are derived from melanoblasts which originate in the neural crest. The dorsoventral migration of melanoblasts has been visualized in pigment stripes seen in aggregation chimeras, and the width of these bands has suggested that the entire pigmentation of the coat is derived from a small number of founder cells. We have generated mosaic mice by marking single melanoblasts in utero to gain information on the clonal history of pigment-forming cells. A retroviral vector carrying the human tyrosinase gene was constructed and microinjected into neurulating albino mouse embryos. Albino mice are devoid of pigmentation due to deficiency of tyrosinase. Thus, transduction of the wild-type gene into the otherwise normal melanoblasts should rescue the mutant phenotype, giving rise to patches of pigmentation, which correspond to the area colonized by the mitotic progeny of a marked clone. Mosaic animals derived from the injected embryos indeed showed pigmented bands with a width strikingly similar to the ‘standard’ stripes seen in aggregation chimeras. These results are consistent with the notion that the unit width bands seen in aggregation chimeras represent the clonal progeny of a single melanoblast and verify Mintz's (1967) conclusion that a few founder melanoblasts give rise to coat pigmentation. The pigment cells of the eye are of dual origin: the melanocytes in choroid and outer layer of the iris are derived from the neural crest and those in the pigment layer of the retina from the neuroepithelium of the optic cup. Marked clones in both lineages were observed in the eyes of many mosaic animals.

nacre encodes a zebrafish microphthalmia-related protein that regulates neural-crest-derived pigment cell fate

Development ◽  
1999 ◽  
Vol 126 (17) ◽  
pp. 3757-3767 ◽  
Author(s):  
J.A. Lister ◽  
C.P. Robertson ◽  
T. Lepage ◽  
S.L. Johnson ◽  
D.W. Raible
Keyword(s):  
Transcription Factor ◽  
Retinal Pigment Epithelium ◽  
Neural Crest ◽  
Cell Fate ◽  
Pigment Cell ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Pigment Cells ◽  
Evolutionary Divergence ◽  
Wild Type

We report the isolation and identification of a new mutation affecting pigment cell fate in the zebrafish neural crest. Homozygous nacre (nac(w2)) mutants lack melanophores throughout development but have increased numbers of iridophores. The non-crest-derived retinal pigment epithelium is normal, suggesting that the mutation does not affect pigment synthesis per se. Expression of early melanoblast markers is absent in nacre mutants and transplant experiments suggested a cell-autonomous function in melanophores. We show that nac(w2) is a mutation in a zebrafish gene encoding a basic helix-loop-helix/leucine zipper transcription factor related to microphthalmia (Mitf), a gene known to be required for development of eye and crest pigment cells in the mouse. Transient expression of the wild-type nacre gene restored melanophore development in nacre(−/−) embryos. Furthermore, misexpression of nacre induced the formation of ectopic melanized cells and caused defects in eye development in wild-type and mutant embryos. These results demonstrate that melanophore development in fish and mammals shares a dependence on the nacre/Mitf transcription factor, but that proper development of the retinal pigment epithelium in the fish is not nacre-dependent, suggesting an evolutionary divergence in the function of this gene.

Embryonic stem cell-mediated transfer and correct regulation of the chicken delta-crystallin gene in developing mouse embryos

Development ◽  
1988 ◽  
Vol 102 (2) ◽  
pp. 259-269 ◽  
Author(s):  
Y. Takahashi ◽  
K. Hanaoka ◽  
M. Hayasaka ◽  
K. Katoh ◽  
Y. Kato ◽  
...  
Keyword(s):  
High Efficiency ◽  
Piriform Cortex ◽  
Embryonic Stem ◽  
Mutant Gene ◽  
Mouse Embryos ◽  
Es Cell ◽  
Wild Type ◽  
Flanking Sequence ◽  
Mouse Tissues ◽  
Type Gene

To study regulation of delta-crystallin expression during ontogeny, we transferred the gene from chicken into developing mouse embryos by first transforming an embryonic stem (ES) cell line of mouse and then producing chimaeric embryos by combining them with normal mouse embryos. Using this technique, genes were transferred into a variety of developing mouse tissues with high efficiency. Two delta-crystallin gene constructs were used: the wild-type gene with 2200 bp of the 5′ flanking sequence, shown to be lens-specific in an assay using cultured mouse cells, and a mutant gene with 51 bp of the 5′ flanking sequence, lacking the sequence required for expression in lens cells. Five independent lines carrying the former and two lines carrying the latter were employed in producing chimaeras. In the chimaeric embryos having the wild-type gene, delta-crystallin was expressed in the lens and in specific regions of the primitive central nervous system (CNS) as is seen in embryonic expression in the chicken. In adult mouse chimaeras also, expression was restricted to the lens and the CNS, in the pyramidal neurones of the piriform cortex and the hippocampus. delta-crystallin expression in these tissues is due to proper transcriptional regulation, since no expression was observed when chimaeras were produced with the ES lines carrying the mutant gene. The experimental results reported here demonstrate the advantage of ES-cell-mediated gene transfer in the study of embryonic gene regulation, because a number of gene constructs and chromosomal sites can be analysed shortly after embryo manipulation without requiring gene transmission to the next generation.

scholarly journals An analysis of pigment cell development in the periodic albino mutant of Xenopus

Development ◽  
1979 ◽  
Vol 52 (1) ◽  
pp. 165-170
Author(s):  
Gillian J. MacMillan
Keyword(s):  
Cell Differentiation ◽  
Neural Crest ◽  
Pigment Cell ◽  
Cell Development ◽  
Pigment Cells ◽  
Wild Type ◽  
Mutant Effect ◽  
Albino Mutant ◽  
Cells Cultured ◽  
Periodic Albino

The periodic albino mutant (apap) of Xenopus in which the development of melanophoresis impaired, is further reported here to possess an aberrant pattern of iridophore differentiation. The development of mutant and wild-type neural crest explants isolated in vesicles derived from tissues from identical and different genotypes was examined to determine if the mutant effect resides in the pigment cells or is mediated by the environmental tissues. Mutant melanophores and iridophores cultured in either mutant or wild-type tissues exhibited mutant patterns of differentiation. Wild-type pigment cells cultured in both wild-type and mutant tissues exhibited wild-type patterns of differentiation. Hence the mutation affects the capacities of melanoblasts and iridoblasts to differentiate but not the ability of the environmental tissues to support pigment cell differentiation.

Cardiac transthyretin wild-type amyloidosis (ATTRwt): a prospective study of 400 patients followed at the Italian referral center

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
P Milani ◽  
L Obici ◽  
R Mussinelli ◽  
M Basset ◽  
G Manfrinato ◽  
...  
Keyword(s):  
Natural History ◽  
Median Survival ◽  
Troponin I ◽  
Stage I ◽  
Stage Ii ◽  
Stage Iii ◽  
Wild Type ◽  
Staging Systems ◽  
Significant Difference ◽  
History Of

Abstract Background Cardiac wild type transthyretin (ATTRwt) amyloidosis, formerly known as senile systemic amyloidosis, is an increasingly recognized, progressive, and fatal cardiomyopathy. Two biomarkers staging systems were proposed based on NT-proBNP (in both cases) and troponin or estimated glomerular filtration rate, that are able to predict survival in this population. The availability of novel effective treatments requires large studies to describe the natural history of the disease in different populations. Objective To describe the natural history of the disease in a large, prospective, national series. Methods Starting in 2007, we protocolized data collection in all the patients diagnosed at our center (n=400 up to 7/2019). Results The referrals to our center increased over time: 5 cases (1%) between 2007–2009, 33 (9%) in 2010–2012, 90 (22%) in 2013–2015 and 272 (68%) in 2016–2019. Median age was 76 years [interquartile range (IQR): 71–80 years] and 372 patients (93%) were males. One hundred and seventy-three (43%) had atrial fibrillation, 63 (15%) had a history of ischemic cardiomyopathy and 64 (15%) underwent pacemaker or ICD implantation. NYHA class was I in 58 subjects (16%), II in 225 (63%) and III in 74 (21%). Median NT-proBNP was 3064 ng/L (IQR: 1817–5579 ng/L), troponin I 0.096 ng/mL (IQR: 0.063–0.158 ng/mL), eGFR 62 mL/min (IQR: 50–78 mL/min). Median IVS was 17 mm (IQR: 15–19 mm), PW 16 mm (IQR: 14–18 mm) and EF 53% (IQR: 45–57%). One-hundred and forty-eight subjects (37%) had a concomitant monoclonal component in serum and/or urine and/or an abnormal free light chain ratio. In these patients, the diagnosis was confirmed by immunoelectron microscopy or mass spectrometry. In 252 (63%) the diagnosis was based on bone scintigraphy. DNA analysis for amyloidogenic mutations in transthyretin and apolipoprotein A-I genes was negative in all subjects. The median survival of the whole cohort was 59 months. The Mayo Clinic staging based on NT-proBNP (cutoff: 3000 ng/L) and troponin I (cutoff: 0.1 ng/mL) discriminated 3 different groups [stage I: 131 (35%), stage II: 123 (32%) and stage III: 127 (33%)] with different survival between stage I and II (median 86 vs. 81 months, P=0.04) and between stage II and III (median 81 vs. 62 months, P<0.001). The UK staging system (NT-proBNP 3000 ng/L and eGFR 45 mL/min), discriminated three groups [stage I: 170 (45%), stage II: 165 (43%) and stage III: 45 (12%)] with a significant difference in survival: between stage I and stage II (86 vs. 52 months, P<0.001) and between stage II and stage III (median survival 52 vs. 33 months, P=0.045). Conclusions This is one of the largest series of patients with cardiac ATTRwt reported so far. Referrals and diagnoses increased exponentially in recent years, One-third of patients has a concomitant monoclonal gammopathy and needed tissue typing. Both the current staging systems offered good discrimination of staging and were validated in our independent cohort. Funding Acknowledgement Type of funding source: None

The DNA Binding Protein Rfg1 Is a Repressor of Filamentation inCandida albicans

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1503-1512 ◽  
Author(s):  
Roy A Khalaf ◽  
Richard S Zitomer
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Hyphal Growth ◽  
Dna Binding Protein ◽  
Homozygous Deletion ◽  
Wild Type ◽  
Pathogenic Yeast ◽  
Repression Complex ◽  
Type Gene ◽  
Repression Domain

AbstractWe have identified a repressor of hyphal growth in the pathogenic yeast Candida albicans. The gene was originally cloned in an attempt to characterize the homologue of the Saccharomyces cerevisiae Rox1, a repressor of hypoxic genes. Rox1 is an HMG-domain, DNA binding protein with a repression domain that recruits the Tup1/Ssn6 general repression complex to achieve repression. The C. albicans clone also encoded an HMG protein that was capable of repression of a hypoxic gene in a S. cerevisiae rox1 deletion strain. Gel retardation experiments using the purified HMG domain of this protein demonstrated that it was capable of binding specifically to a S. cerevisiae hypoxic operator DNA sequence. These data seemed to indicate that this gene encoded a hypoxic repressor. However, surprisingly, when a homozygous deletion was generated in C. albicans, the cells became constitutive for hyphal growth. This phenotype was rescued by the reintroduction of the wild-type gene on a plasmid, proving that the hyphal growth phenotype was due to the deletion and not a secondary mutation. Furthermore, oxygen repression of the hypoxic HEM13 gene was not affected by the deletion nor was this putative ROX1 gene regulated positively by oxygen as is the case for the S. cerevisiae gene. All these data indicate that this gene, now designated RFG1 for Repressor of Filamentous Growth, is a repressor of genes required for hyphal growth and not a hypoxic repressor.

scholarly journals Occurrence of Repeat Induced Point Mutation in Long Segmental Duplications of Neurospora

Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 125-136 ◽  
Author(s):  
David D Perkins ◽  
Brian S Margolin ◽  
Eric U Selker ◽  
S D Haedo
Keyword(s):  
Point Mutation ◽  
Sexual Cycle ◽  
Segmental Duplications ◽  
Wild Type ◽  
Single Chain ◽  
Base Pairs ◽  
Gene Size ◽  
Type Gene ◽  
Repeat Induced Point Mutation

Abstract Previous studies of repeat induced point mutation (RIP) have typically involved gene-size duplications resulting from insertion of transforming DNA at ectopic chromosomal positions. To ascertain whether genes in larger duplications are subject to RIP, progeny were examined from crosses heterozygous for long segmental duplications obtained using insertional or quasiterminal translocations. Of 17 distinct mutations from crossing 11 different duplications, 13 mapped within the segment that was duplicated in the parent, one was closely linked, and three were unlinked. Half of the mutations in duplicated segments were at previously unknown loci. The mutations were recessive and were expressed both in haploid and in duplication progeny from Duplication × Normal, suggesting that both copies of the wild-type gene had undergone RIP. Seven transition mutations characteristic of RIP were found in 395 base pairs (bp) examined in one ro-11 allele from these crosses and three were found in ~750 bp of another. A single chain-terminating C to T mutation was found in 800 bp of arg-6. RIP is thus responsible. These results are consistent with the idea that the impaired fertility that is characteristic of segmental duplications is due to inactivation by RIP of genes needed for progression through the sexual cycle.

scholarly journals Natural History of Wild-Type Transthyretin Cardiac Amyloidosis and Risk Stratification Using a Novel Staging System

2016 ◽  
Vol 68 (10) ◽  
pp. 1014-1020 ◽  
Author(s):  
Martha Grogan ◽  
Christopher G. Scott ◽  
Robert A. Kyle ◽  
Steven R. Zeldenrust ◽  
Morie A. Gertz ◽  
...  
Keyword(s):  
Natural History ◽  
Risk Stratification ◽  
Cardiac Amyloidosis ◽  
Staging System ◽  
Wild Type ◽  
History Of

scholarly journals Identification and Characterization of a Peptidoglycan Hydrolase, MurA, of Listeria monocytogenes, a Muramidase Needed for Cell Separation

2003 ◽  
Vol 185 (23) ◽  
pp. 6801-6808 ◽  
Author(s):  
Shannon A. Carroll ◽  
Torsten Hain ◽  
Ulrike Technow ◽  
Ayub Darji ◽  
Philippos Pashalidis ◽  
...  
Keyword(s):  
Cell Wall ◽  
Listeria Monocytogenes ◽  
Cell Separation ◽  
Bacterial Species ◽  
Surface Protein ◽  
Wild Type ◽  
Terminal Domain ◽  
Cell Wall Hydrolase ◽  
Characteristic Features ◽  
Type Gene

ABSTRACT A novel cell wall hydrolase encoded by the murA gene of Listeria monocytogenes is reported here. Mature MurA is a 66-kDa cell surface protein that is recognized by the well-characterized L. monocytogenes-specific monoclonal antibody EM-7G1. MurA displays two characteristic features: (i) an N-terminal domain with homology to muramidases from several gram-positive bacterial species and (ii) four copies of a cell wall-anchoring LysM repeat motif present within its C-terminal domain. Purified recombinant MurA produced in Escherichia coli was confirmed to be an authentic cell wall hydrolase with lytic properties toward cell wall preparations of Micrococcus lysodeikticus. An isogenic mutant with a deletion of murA that lacked the 66-kDa cell wall hydrolase grew as long chains during exponential growth. Complementation of the mutant strain by chromosomal reintegration of the wild-type gene restored expression of this murein hydrolase activity and cell separation levels to those of the wild-type strain. Studies reported herein suggest that the MurA protein is involved in generalized autolysis of L. monocytogenes.

scholarly journals CLN3 expression is sufficient to restore G1-to-S-phase progression in Saccharomyces cerevisiae mutants defective in translation initiation factor eIF4E

1999 ◽  
Vol 340 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Parisa DANAIE ◽  
Michael ALTMANN ◽  
Michael N. HALL ◽  
Hans TRACHSEL ◽  
Stephen B. HELLIWELL
Keyword(s):  
Cell Cycle ◽  
S Phase ◽  
Translation Initiation Factor ◽  
Yeast Cells ◽  
Initiation Factor ◽  
G1 Phase ◽  
Mrna Levels ◽  
Wild Type ◽  
Phase Progression ◽  
Type Gene

The essential cap-binding protein (eIF4E) of Saccharomycescerevisiae is encoded by the CDC33 (wild-type) gene, originally isolated as a mutant, cdc33-1, which arrests growth in the G1 phase of the cell cycle at 37 °C. We show that other cdc33 mutants also arrest in G1. One of the first events required for G1-to-S-phase progression is the increased expression of cyclin 3. Constructs carrying the 5ʹ-untranslated region of CLN3 fused to lacZ exhibit weak reporter activity, which is significantly decreased in a cdc33-1 mutant, implying that CLN3 mRNA is an inefficiently translated mRNA that is sensitive to perturbations in the translation machinery. A cdc33-1 strain expressing either stable Cln3p (Cln3-1p) or a hybrid UBI4 5ʹ-CLN3 mRNA, whose translation displays decreased dependence on eIF4E, arrested randomly in the cell cycle. In these cells CLN2 mRNA levels remained high, indicating that Cln3p activity is maintained. Induction of a hybrid UBI4 5ʹ-CLN3 message in a cdc33-1 mutant previously arrested in G1 also caused entry into a new cell cycle. We conclude that eIF4E activity in the G1-phase is critical in allowing sufficient Cln3p activity to enable yeast cells to enter a new cell cycle.

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