Ultrastructural effects of Helminthosporium maydis race T toxin on isolated corn mitochondria and mitochondria within corn protoplasts

1980 ◽  
Vol 58 (14) ◽  
pp. 1562-1570 ◽  
Author(s):  
D. W. York ◽  
E. D. Earle ◽  
V. E. Gracen
Keyword(s):  
Treatment Time ◽  
Living Cells ◽  
Primary Site ◽  
Ultrastructural Changes ◽  
Male Sterile ◽  
Bipolaris Maydis ◽  
Short Treatment ◽  
Matrix Density ◽  
Corn Roots ◽  
Male Sterile Cytoplasm

Mitochondria isolated from Texas male-sterile cytoplasm (T) corn roots and mitochondria within T protoplasts showed similar ultrastructural changes after treatment with Helminthosporium (Bipolaris) maydis race T (HmT) toxin. These changes included loss of matrix density, disruption of cristae, and swelling. Damage was observed in isolated T mitochondria after 1-min treatments and in mitochondria within T protoplasts after 5-min treatments. At low toxin concentrations or short treatment times, some mitochondria in isolated preparations and in individual protoplasts were altered whereas others were not. With increases in treatment time or toxin concentrations, all mitochondria were damaged. N cytoplasm mitochondria were unaffected by much higher toxin concentrations and longer treatment times. No ultrastructural effects of HmT toxin on other cytoplasmic components were observed, indicating that mitochondria are structurally affected before other cellular sites. The results support the hypothesis that mitochondria are the primary site of HmT toxin damage in living cells.

Ciliary coordination in newt lung cells requires microtubule-based linkages between basal bodies: A correlative light and EM study

1992 ◽  
Vol 50 (1) ◽  
pp. 570-571
Author(s):  
Robert Hard ◽  
Gerald Rupp ◽  
Matthew L. Withiam-Leitch ◽  
Lisa Cardamone
Keyword(s):  
Basal Body ◽  
Untreated Control ◽  
Beat Frequency ◽  
Primary Cultures ◽  
Living Cells ◽  
Power Stroke ◽  
Ultrastructural Changes ◽  
Lung Cells ◽  
Basal Bodies ◽  
Ciliated Cells

In a coordinated field of beating cilia, the direction of the power stroke is correlated with the orientation of basal body appendages, called basal feet. In newt lung ciliated cells, adjacent basal feet are interconnected by cold-stable microtubules (basal MTs). In the present study, we investigate the hypothesis that these basal MTs stabilize ciliary distribution and alignment. To accomplish this, newt lung primary cultures were treated with the microtubule disrupting agent, Colcemid. In newt lung cultures, cilia normally disperse in a characteristic fashion as the mucociliary epithelium migrates from the tissue explant. Four arbitrary, but progressive stages of dispersion were defined and used to monitor this redistribution process. Ciliaiy beat frequency, coordination, and dispersion were assessed for 91 hrs in untreated (control) and treated cultures. When compared to controls, cilia dispersed more rapidly and ciliary coordination decreased markedly in cultures treated with Colcemid (2 mM). Correlative LM/EM was used to assess whether these effects of Colcemid were coupled to ultrastructural changes. Living cells were defined as having coordinated or uncoordinated cilia and then were processed for transmission EM.

Chimeric mitochondrial genes expressed in the C male-sterile cytoplasm of maize

1991 ◽  
Vol 20 (6) ◽  
pp. 475-482 ◽  
Author(s):  
R. E. Dewey ◽  
D. H. Timothy ◽  
C. S. Levings
Keyword(s):  
Mitochondrial Genes ◽  
Male Sterile ◽  
Male Sterile Cytoplasm

scholarly journals Uprighting Impacted Mandibular Second Molar Using a Skeletal Anchorage: A Case Report

2020 ◽  
Vol 8 (4) ◽  
pp. 129
Author(s):  
Federica Altieri ◽  
Rosanna Guarnieri ◽  
Martina Mezio ◽  
Gabriella Padalino ◽  
Angela Cipollone ◽  
...  
Keyword(s):  
Case Report ◽  
Treatment Time ◽  
Skeletal Anchorage ◽  
Impacted Tooth ◽  
Short Treatment ◽  
Second Molar ◽  
Advantages And Disadvantages ◽  
Mandibular Molar ◽  
Mandibular Second Molar ◽  
The Impact

The aim of this case report is to present an innovative combined orthodontic-surgical technique to disimpact mandibular second molar (MM2) using an orthodontic miniscrew and an elastic chain. The impact on the Oral health-related quality of life (OHRQoL) was also evaluated. Using the present techinique, it is possible to expose the impacted tooth, insert a self-drilling miniscrew in the retromolar area, and remove the bud of third mandibular molar. At the same time the orthodontic force is applied with the use of an elastomeric chain that connects the head of miniscrew and vestibular and oral buttons bonded on MM2. A close traction is performed for the whole treatment time without the reactivation of the elastic force. The use of skeletal anchorage allowed the disimpaction of impacted MM2 in a short treatment time (about three months) avoiding the typical biomechanical side effects of traditional orthodontic appliance and increasing the effectiveness of the treatment. Further studies are necessary to evaluate the real advantages and disadvantages of this combined orthodontic-surgical approach.

Fertility Restoration of Male‐Sterile Cytoplasm in Wild Sunflowers 1

Crop Science ◽  
1975 ◽  
Vol 15 (5) ◽  
pp. 724-726 ◽  
Author(s):  
Juan Dominguez Gimenez ◽  
Gerhardt N. Fick
Keyword(s):  
Fertility Restoration ◽  
Male Sterile ◽  
Male Sterile Cytoplasm

The effect of genotype × cytoplasm interaction on meiotic behaviour of maize chromosomes

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 653-658 ◽  
Author(s):  
M. M. Kruleva ◽  
A. B. Korol ◽  
T. G. Dankov ◽  
V. G. Skorpan ◽  
I. A. Preygel
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Relative Stability ◽  
Chiasma Frequency ◽  
Chiasma Formation ◽  
Meiotic Behaviour ◽  
Male Sterile ◽  
Maize Hybrids ◽  
Male Sterile Cytoplasm ◽  
Cytoplasmic Sterility

The effect of four isogenic cytoplasmic types, normal, Salvador, Texas, and Charrua (the latter three causing male sterility), on the process of chiasma formation has been studied using two different maize hybrids. The cytoplasmic male sterility determinants have been shown to reduce the rate of interstitial exchanges per nucleus and per bivalent and the frequency of univalents. Increased variation between plants and relative stability of the intercellular variation within a plant have been observed for the parameters studied. It is concluded that the determinants of cytoplasmic sterility lower the probability of additional exchanges (relative to the obligate one) and reduce the frequency of premature disruption of one-exchange chromosome associations.Key words: maize, chiasma frequency, male sterile cytoplasm, univalent formation, genotype × cytoplasm interaction.

Advancement in CMS Based Hybrid Development in Cauliflower (Brassica oleracea var. Botrytis)

2020 ◽  
pp. 18-24
Author(s):  
Amit Kumar ◽  
Anjani Kumar ◽  
Chandan Roy
Keyword(s):  
Male Sterility ◽  
Somatic Hybridization ◽  
Microspore Culture ◽  
Intermediate Stage ◽  
Restorer Line ◽  
Undesirable Effect ◽  
Male Sterile ◽  
Sib Mating ◽  
Male Sterile Cytoplasm ◽  
Hybrid Development

Among the different mechanism of male sterility operated in the Brassica group crop. Cytoplasmic male sterility mechanism is most suitable for hybrid development in cauliflower because here the curd (intermediate stage) is an edible part of the cauliflower. Further, there is no requirement of restorer line in this case as required in other seed crop. For the multiplication and maintenance of the different lines (A line and B line), sib mating and selfing is not always desirable. In fact, in such situation doubled haploid production through microspore culture is a more appropriate mechanism. Apart from this, the undesirable effect of integration of male sterile cytoplasm can be mitigated by adopting the repeated back crossing, through chloroplast substitution or somatic hybridization mechanism.

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