scholarly journals The hooded mutant of Lathyrus odoratus (Fabaceae) is associated with a cycloidea gene mutation

Botany ◽  
2018 ◽  
Vol 96 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Christine Woollacott ◽  
Quentin C.B. Cronk

The hooded (hdd) floral mutant of Lathyrus odoratus L. (sweet pea) has a concave standard petal compared with the flat standard petal of the wild type. This trait was used by Bateson, Punnett, and Saunders in early studies of Mendelian inheritance (c.1905). Here we provide four lines of evidence that this phenotype results from a mutation in the CYCLOIDEA2 (CYC2) gene. (i) CYC2 is expressed in the standard petals of wild-type L. odoratus, whereas the same methods fail to detect expression in hdd plants. (ii) Genomic sequencing reveals that the CYC2 gene sequence of hdd plants is truncated at the TCP box and likely nonfunctional. (iii) In a population of 118 plants, the hdd phenotype cosegregated with the mutant allele of CYC2 without exception. (iv) CYC2 is known to act as a dorsal petal identity gene. Consistent with this, the standard petal in hdd flowers has the epidermal and pigment characteristics of wing petals, indicating that the hdd mutation results in a shift in dorsiventral petal-type identity. We conclude that the mutation in CYC2 is responsible for the hdd phenotype, and is therefore the L. odoratus equivalent of the lobed standard (lst1) mutant in Pisum.

2000 ◽  
Vol 76 (2) ◽  
pp. 135-147 ◽  
Author(s):  
ANATOLY RUVINSKY ◽  
WARREN D. FLOOD ◽  
TONG ZHANG ◽  
FRANK COSTANTINI

AxinFu is a mutation in mice that causes fused tails and other developmental abnormalities as a result of insertion of an intracisternal-A particle (IAP), a murine retrotransposon, into intron 6. In a small percentage of offspring we found that the mutant allele reverts to wild-type through loss of the insertion with concomitant disappearance of the mutant phenotype. Investigation of a series of microsatellite loci in the proximal region of chromosome 17 revealed novel alleles which arise simultaneously with disappearance of IAP from AxinFu. These novel microsatellite variants are distinct from the parental alleles and those so far discovered are organized into two haplotypes. Both haplotypes demonstrate stable Mendelian inheritance. Results show that these rearrangements, which are involved in the production of the new haplotypes, exceed millions of base pairs.


Genetics ◽  
2002 ◽  
Vol 161 (2) ◽  
pp. 563-574
Author(s):  
Laura K Palmer ◽  
Darren Wolfe ◽  
Jessica L Keeley ◽  
Ralph L Keil

Abstract Volatile anesthetics affect all cells and tissues tested, but their mechanisms and sites of action remain unknown. To gain insight into the cellular activities of anesthetics, we have isolated genes that, when overexpressed, render Saccharomyces cerevisiae resistant to the volatile anesthetic isoflurane. One of these genes, WAK3/TAT1, encodes a permease that transports amino acids including leucine and tryptophan, for which our wild-type strain is auxotrophic. This suggests that availability of amino acids may play a key role in anesthetic response. Multiple lines of evidence support this proposal: (i) Deletion or overexpression of permeases that transport leucine and/or tryptophan alters anesthetic response; (ii) prototrophic strains are anesthetic resistant; (iii) altered concentrations of leucine and tryptophan in the medium affect anesthetic response; and (iv) uptake of leucine and tryptophan is inhibited during anesthetic exposure. Not all amino acids are critical for this response since we find that overexpression of the lysine permease does not affect anesthetic sensitivity. These findings are consistent with models in which anesthetics have a physiologically important effect on availability of specific amino acids by altering function of their permeases. In addition, we show that there is a relationship between nutrient availability and ubiquitin metabolism in this response.


Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 437-446 ◽  
Author(s):  
Lisa Girard ◽  
Michael Freeling

Abstract Insertions of Mutator transposons into maize genes can generate suppressible alleles. Mu suppression is when, in the absence of Mu activity, the phenotype of a mutant allele reverts to that of its progenitor. Here we present the characterization of five dominant Mu-suppressible alleles of the knox (knotted1-like homeobox) genes liguleless3 and rough sheath1, which exhibit neomorphic phenotypes in the leaves. RNA blot analysis suggests that Mu suppression affects only the neomorphic aspect of the allele, not the wild-type aspect. Additionally, Mu suppression appears to be exerting its effects at the level of transcription or transcript accumulation. We show that truncated transcripts are produced by three alleles, implying a mechanism for Mu suppression of 5′ untranslated region insertion alleles distinct from that which has been described previously. Additionally, it is found that Mu suppression can be caused by at least three different types of Mutator elements. Evidence presented here suggests that whether an allele is suppressible or not may depend upon the site of insertion. We cite previous work on the knox gene kn1, and discuss our results in the context of interactions between Mu-encoded products and the inherently negative regulation of neomorphic liguleless3 and rough sheath1 transcription.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Kyoko Yoshizaki ◽  
Akihiro Hirata ◽  
Hiroyuki Matsushita ◽  
Naohito Nishii ◽  
Mifumi Kawabe ◽  
...  

Abstract Background The prevalence of gastrointestinal (GI) neoplastic polyps in Jack Russell terriers (JRTs) has increased in Japan since the late 2000s. Recently, we demonstrated that JRTs with GI polyps harbor identical germline variant in the APC gene (c.[462_463delinsTT]) in the heterozygous state. Thus, this disease is an autosomal dominant hereditary disorder. Although the affected JRTs have distinct features, such as the development of multiple GI polyps and an early age of disease onset, genetic testing is indispensable for a definitive diagnosis. Here, polymerase chain reaction (PCR)-based assays capable of detecting germline APC variant were designed and validated using synthetic wild-type and mutant DNAs and genomic DNAs from carrier and non-carrier dogs. Result First, the PCR-restriction fragment length polymorphism (PCR-RFLP) assay was developed by taking advantage of the germline APC variant creating a new restriction site for MseI. In the PCR-RFLP assay, the 156-bp region containing the variant site was amplified by PCR and subsequently digested with MseI, yielding diagnostic 51 and 58 bp fragments from the mutant allele and allowing determination of the APC genotypes. It was possible to determine the genotypes using genomic DNA extracted from the peripheral blood, buccal swab, or formalin-fixed paraffin-embedded tissue. Next, a TaqMan duplex real-time PCR assay was developed, where a 78-bp region flanking the variant was amplified in the presence of wild-type allele- and mutant allele-specific fluorescent probes. Using blood-derived DNA, altogether 40 cycles of PCR amplification determined the APC genotypes of all examined samples by measuring the fluorescence intensities. Importantly, false-positive and false-negative errors were never detected in both assays. Conclusion In this study, we developed highly reliable genetic tests for hereditary GI polyposis in JRTs, providing accurate assessment of the presence of the causative germline APC variant. The genotyping assays could contribute to the diagnosis and prevention of hereditary GI polyposis in dogs.


Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Steven J Sandler ◽  
Hardeep S Samra ◽  
Alvin J Clark

Abstract First identified as an essential component of the ϕX174 in vitro DNA replication system, PriA has ATPase, helicase, translocase, and primosome-assembly activities. priA1::kan strains of Escherichia coli are sensitive to UV irradiation, deficient in homologous recombination following transduction, and filamentous. priA2::kan strains have eightfold higher levels of uninduced SOS expression than wild type. We show that (1) priA1::kan strains have eightfold higher levels of uninduced SOS expression, (2) priA2::kan strains are UVS and Rec−, (3) lexA3 suppresses the high basal levels of SOS expression of a priA2::kan strain, and (4) plasmid-encoded priA300 (K230R), a mutant allele retaining only the primosome-assembly activity of priA+, restores both UVR and Rec+ phenotypes to a priA2::kan strain. Finally, we have isolated 17 independent UVR Rec+ revertants of priA2::kan strains that carry extragenic suppressors. All 17 map in the C-terminal half of the dnaC gene. DnaC loads the DnaB helicase onto DNA as a prelude for primosome assembly and DNA replication. We conclude that priA's primosome-assembly activity is essential for DNA repair and recombination and that the dnaC suppressor mutations allow these processes to occur in the absence of priA.


2015 ◽  
Vol 59 (3) ◽  
pp. 1818-1821 ◽  
Author(s):  
Luicer A. Ingasia ◽  
Hoseah M. Akala ◽  
Mabel O. Imbuga ◽  
Benjamin H. Opot ◽  
Fredrick L. Eyase ◽  
...  

ABSTRACTThe prevalence of a genetic polymorphism(s) at codon 268 in the cytochromebgene, which is associated with failure of atovaquone-proguanil treatment, was analyzed in 227Plasmodium falciparumparasites from western Kenya. The prevalence of the wild-type allele was 63%, and that of the Y268S (denoting a Y-to-S change at position 268) mutant allele was 2%. There were no pure Y268C or Y268N mutant alleles, only mixtures of a mutant allele(s) with the wild type. There was a correlation between parasite 50% inhibitory concentration (IC50) and parasite genetic polymorphism; mutant alleles had higher IC50s than the wild type.


2004 ◽  
Vol 92 (09) ◽  
pp. 503-508 ◽  
Author(s):  
Hans-Ulrich Pauer ◽  
Thomas Renné ◽  
Bernhard Hemmerlein ◽  
Tobias Legler ◽  
Saskia Fritzlar ◽  
...  

SummaryTo analyze the biological role of factor XII (FXII, Hageman Factor) in vivo, we generated mice deficient for FXII using a gene targeting approach on two distinct genetic backgrounds, i.e. mixed C57Bl/6J X 129X1/SvJ and inbred 129X1/SvJ. Homozygous FXII knockout (FXII-/-) mice showed no FXII plasma activity and had a markedly prolonged activated partial thromboplastin time (aPTT). In contrast, coagulation factors XI, VIII, IX, X,VII,V, II and fibrinogen did not differ between FXII-/- mice and their wild-type littermates. Heterozygous matings segregated according to the Mendelian inheritance indicating that FXII deficiency does not increase fetal loss. Furthermore, matings of FXII-/- males and FXII-/females resulted in normal litter sizes demonstrating that total FXII deficiency in FXII-/females does not affect pregnancy outcome. Also, gross and histological anatomy of FXII-/mice was indistinguishable from that of their wild-type littermates on both genetic backgrounds. Thus it appears that deficiency of murine FXII does not cause thrombophilia or impaired fibrinolysis in vivo. These results indicate that FXII deficiency does not affect hemostasis in vivo and we anticipate that the FXII-/mice will be helpful to elucidate the biological role(s) of FXII in health and disease.


1999 ◽  
Vol 77 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Robert M Penner ◽  
Nathan J Roth ◽  
Beatrice Rob ◽  
Helga Lay ◽  
Reuben E Huber

Substitutions for Tyr-503 of β-galactosidase caused large decreases of the activity. Both the galactosylation (k2) and degalactosylation (k3) rates were decreased. Substitutions by residues without transferable protons, caused k3 to decrease much more than k2 while substitutions with residues having transferable protons, caused approximately equal decreases of k2 and k3. Several lines of evidence showed this. The Km values of the substituted enzymes were much smaller than those for the wild type if the substituted amino acid residues did not have transferable protons; this was not the case when the substituted residues had transferable protons. Inhibition studies showed that the Km values were not small because of small Ks values but were small because of relatively small k3 values (compared with the k2 values). The conclusion that the k3 values are small relative to k2 upon substitution with residues without transferable protons is also based upon other studies: studies indicating that the reaction rates were similar with different substrates, studies in the presence of alcohol acceptors, studies showing that the rate of inactivation by 2,4-dinitrophenyl-2-deoxy-2-F-β-D-galactopyranoside decreased much less than the rate of reactivation; studies on burst kinetics, and pH studies. The data suggest that Tyr-503 may be important for the degalactosylation reaction because of its ability to transfer protons and thereby facilitate cleavage of the transient covalent bond between galactose and Glu-537. Key words: β-galactosidase, tyrosine, mechanism, acid catalysis.


Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2274-2281 ◽  
Author(s):  
H.R. Lijnen ◽  
K. Okada ◽  
O. Matsuo ◽  
D. Collen ◽  
M. Dewerchin

2-antiplasmin (2-AP) is the main physiologic plasmin inhibitor in mammalian plasma. Inactivation of the murine 2-AP gene was achieved by replacing, through homologous recombination in embryonic stem cells, a 7-kb genomic sequence encoding the entire murine protein (exon 2 through part of exon 10, including the stop codon) with theneomycin resistance expression cassette. Germline transmission of the mutated allele was confirmed by Southern blot analysis. Mendelian inheritance of the inactivated 2-AP allele was observed, and homozygous deficient (2-AP−/−) mice displayed normal fertility, viability, and development. Reverse transcription-polymerase chain reaction confirmed the absence of 2-AP mRNA in kidney and liver from 2-AP−/− mice, in contrast to wild-type (2-AP+/+) mice. Immunologic and functional 2-AP levels were undetectable in plasma of 2-AP−/− mice, and were about half of wild-type in heterozygous littermates (2-AP+/−). Other hemostasis parameters, including plasminogen activator inhibitor-1, plasminogen, fibrinogen, hemoglobin, hematocrit, and blood cell counts were comparable for 2-AP+/+, 2-AP+/−, and 2-AP−/− mice. After amputation of tail or toe tips, bleeding stopped spontaneously in 2-AP+/+, as well as in 2-AP+/− and 2-AP−/− mice. Spontaneous lysis after 4 hours of intravenously injected 125I-fibrin–labeled plasma clots was significantly higher in 2-AP−/− than in 2-AP+/+ mice when injecting clots prepared from 2-AP+/+ plasma (78% ± 5% v 46% ± 9%; mean ± SEM, n = 6 to 7; P = .02) or from 2-AP−/−plasma (81% ± 5% v 46% ± 5%; mean ± SEM, n = 5; P = .008). Four to 8 hours after endotoxin injection, fibrin deposition in the kidneys was significantly reduced in 2-AP−/− mice, as compared with 2-AP+/+ mice (P ≤ .005). Thus, 2-AP−/− mice develop and reproduce normally; they have an enhanced endogenous fibrinolytic capacity without overt bleeding.


1971 ◽  
Vol 48 (3) ◽  
pp. 594-619 ◽  
Author(s):  
Ursula W. Goodenough ◽  
L. Andrew Staehelin

Wild-type chloroplast membranes from Chlamydomonas reinhardi exhibit four faces in freeze-etchreplicas: the complementary Bs and Cs faces are found where the membranes are stacked together; the complementary Bu and Cu faces are found in unstacked membranes. The Bs face carries a dense population of regularly spaced particles containing the large, 160 ± 10 A particles that appear to be unique to chloroplast membranes. Under certain growth conditions, membrane stacking does not occur in the ac-5 strain. When isolated, these membranes remain unstacked, exhibit only Bu and Cu faces, and retain the ability to carry out normal photosynthesis. Membrane stacking is also absent in the ac-31 strain, and, when isolated in a low-salt medium, these membranes remain unstacked and exhibit only Bu and Cu faces. When isolated in a high-salt medium, however, they stack normally, and Bs and Cs faces are produced by this in vitro stacking process. We conclude that certain particle distributions in the chloroplast membrane are created as a consequence of the stacking process, and that the ability of membranes to stack can be modified both by gene mutation and by the ionic environment in which the membranes are found.


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