A Laboratory Exercise for Isolating & Characterizing Microbial Mutants with Metabolic Defects

1993 ◽  
Vol 55 (7) ◽  
pp. 430-433 ◽  
Author(s):  
Frank J. Doe ◽  
John F. Leslie
HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 555b-555
Author(s):  
Chiwon W. Lee

Velvet flower (Salpiglossis sinuata, Solanaceae) can be used as an excellent demonstration plant for horticultural crop breeding classes. Salpiglossis produces large trumpet-like flowers exhibiting an assortment of corolla color and pigmentation pattern. The pistil is large (3 to 4 cm long) with a sticky stigmatal tip and anthers can be easily emasculated prior to anthesis. The large pollen grains are shed in tetrads, which can be separated and individually placed on the stigma. It takes 8 to 9 weeks from seeding to blooming, with a prolific flowering cycle repeated in flushes. Numerous seeds (about 750/capsule) are obtained in 3 weeks after self- or cross-pollination. The influences of three genes that control flower color and pigmentation pattern can be conveniently demonstrated with their dominant and recessive alleles. The R gene controls flower color with red (RR or Rr) being dominant over yellow (rr) flower color. The D gene controls the density of pigmentation with solid (DD or Dd) color being dominant over dilute (dd) color. Corolla color striping is controlled by the St gene with striped (stst) being recessive to non-striped (StSt or Stst) pattern. For example, by using diploid lines of genotypes RRDD (red, solid), RRdd (red, dilute), or rrdd (yellow, dilute) and their crosses, students can easily learn a dominant phenotypic expression in the F1 hybrid and the digenic 9:3:3:1 segregation ratio in the F2 progeny. Another gene (C) that controls flower opening can also be used to show its influence on cleistogamous (closed, self-pollinated, CC or Cc) versus normal chasmogamous (open-pollinated, cc) corolla development. In addition, the induction and use of polyploid (4X, 3X) plants in plant breeding can be effectively demonstrated using this species.


1984 ◽  
Vol 13 (1) ◽  
pp. 50-53
Author(s):  
Kenneth M. Oates ◽  
James Camberato ◽  
M. J. Vepraskas
Keyword(s):  

2012 ◽  
Vol 11 (1) ◽  
pp. 25-32 ◽  
Author(s):  
James West ◽  
James E. Loyd ◽  
Rizwan Hamid

For more than 60 years, researchers have sought to understand the molecular basis of idiopathic pulmonary arterial hypertension (PAH). Recognition of the heritable form of the disease led to the creation of patient registries in the 1980s and 1990s, and discovery of BMPR2 as the cause of roughly 80% of heritable PAH in 2000. With discovery of the disease gene came opportunity for intervention, with focus on 2 alternative approaches. First, it may be possible to correct the effects of BMPR2 mutation directly through interventions targeted at correction of trafficking defects, increasing expression of the unmutated allele, and correction of splicing defects. Second, therapeutic interventions are being targeted at the signaling consequences of BMPR2 mutation. In particular, therapies targeting cytoskeletal and metabolic defects caused by BMPR2 mutation are currently in trials, or will be ready for human trials in the near future. Translation of these findings into therapies is the culmination of decades of research, and holds great promise for treatment of the underlying molecular bases of disease.


Nephron ◽  
1989 ◽  
Vol 51 (4) ◽  
pp. 449-453 ◽  
Author(s):  
Gad Kainer ◽  
Edward Spence ◽  
James C.M. Chan
Keyword(s):  

Author(s):  
Stefano Rizza ◽  
Alessio Luzi ◽  
Maria Mavilio ◽  
Marta Ballanti ◽  
Arianna Massimi ◽  
...  

Abstract Objective To detect premature gluco-metabolic defects among night shift workers with disturbances in circadian rhythms. Design and methods We performed a hypothesis-generating, cross-sectional analysis of anthropometric, metabolic, lipid, and inflammation parameters, comparing active (a-NSW, n = 111) and former (f-NSW, n = 98) rotating night shift workers with diurnal workers (controls, n = 69). All participants were hospital nurses. We also evaluated the Pittsburgh Sleep Quality Index (PSQI) and assessed expression of transcription factors REV-ERBα and BMAL1 in peripheral blood mononuclear cells (PBMCs), as indicators of the molecular clock. Results Both a-NSW and f-NSW participants had significantly higher glycated hemoglobin (HbA1c) and white blood cell counts (WBC) (p < 0.001 for both), PSQI global score (p = 0.001) and diastolic blood pressure levels (p = 0.024) compared with controls. Expression of REV-ERBα/BMAL1 RNA in PBMC was significantly higher in a-NSW (p = 0.05) than in f-NSW or control participants. Multivariate regression analysis showed that working status and PSQI were independent determinants of higher HbA1c levels (p < 0.001). Conclusions We demonstrated that young, healthy night shift workers show subclinical abnormalities in HbA1c and changes in peripheral clock gene expression.


Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1089-1099
Author(s):  
Gwenaël Ruprich-Robert ◽  
Véronique Berteaux-Lecellier ◽  
Denise Zickler ◽  
Arlette Panvier-Adoutte ◽  
Marguerite Picard

Abstract Peroxins (PEX) are proteins required for peroxisome biogenesis. Mutations in PEX genes cause lethal diseases in humans, metabolic defects in yeasts, and developmental disfunctions in plants and filamentous fungi. Here we describe the first large-scale screening for suppressors of a pex mutation. In Podospora anserina, pex2 mutants exhibit a metabolic defect [inability to grow on medium containing oleic acid (OA medium) as sole carbon source] and a developmental defect (inability to differentiate asci in homozygous crosses). Sixty-three mutations able to restore growth of pex2 mutants on OA medium have been analyzed. They fall in six loci (suo1 to suo6) and act as dominant, allele-nonspecific suppressors. Most suo mutations have pleiotropic effects in a pex2+ background: formation of unripe ascospores (all loci except suo5 and suo6), impaired growth on OA medium (all loci except suo4 and suo6), or sexual defects (suo4). Using immunofluorescence and GFP staining, we show that peroxisome biogenesis is partially restored along with a low level of ascus differentiation in pex2 mutant strains carrying either the suo5 or the suo6 mutations. The data are discussed with respect to β-oxidation of fatty acids, peroxisome biogenesis, and cell differentiation.


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