scholarly journals THE RELATIONSHIP OF CROSSING OVER TO CHROMOSOME SYNAPSIS IN A SHORT PARACENTRIC INVERSION

Genetics ◽  
1966 ◽  
Vol 53 (6) ◽  
pp. 1071-1077 ◽  
Author(s):  
Marjorie P Maguire
Keyword(s):  
Paracentric Inversion ◽  
Crossing Over ◽  
Chromosome Synapsis ◽  
Relationship Of ◽  
The Relationship

Novel Investigation of the Deep Band of the Lateral Plantar Aponeurosis and Its Relationship With the Lateral Plantar Nerve

2019 ◽  
Vol 40 (11) ◽  
pp. 1325-1330
Author(s):  
Cameron M. Beck ◽  
Austin R. Dickerson ◽  
Kevin J. Kadado ◽  
Zachary A. Cohen ◽  
Somer E. Blair ◽  
...  
Keyword(s):  
Anatomical Study ◽  
Crossing Over ◽  
Medial Aspect ◽  
Precise Location ◽  
Target Zone ◽  
Plantar Aponeurosis ◽  
Lateral Plantar Nerve ◽  
Relationship Of ◽  
Clinical Potential ◽  
The Relationship

Background: We describe a thick fascial band arising from the medial aspect of the lateral plantar aponeurosis diving deep into the forefoot crossing over a branch of the lateral plantar nerve. Because a review of current literature resulted in limited and outdated sources, we sought to first determine the frequency of this fascial band and the location where it crosses the lateral plantar nerve and, second, discuss the clinical applications these anatomical findings could have. Methods: 50 pairs of cadaveric feet (n = 100) were dissected to investigate for presence of the fascial band and its interaction with the lateral plantar nerve. Images were taken of each foot with the fascial band. ImageJ was used to take 2 measurements assessing the relationship of the tuberosity of the base of the fifth metatarsal to where the nerve crossed deep to the fascial band. Results: Overall, 38% of the feet possessed the fascial band. It was found unilaterally in 10 pairs and bilaterally in 14 pairs. On average, the point at which the lateral plantar nerve passed deep to the fascial band was 2.0 cm medial and 1.7 cm anterior to the tuberosity of the base of the fifth metatarsal. Conclusion: When present, the deep band of the lateral plantar aponeurosis (PA) was consistently found to be crossing the lateral plantar nerve. The discovery of the location where this most commonly occurs has not been previously reported and adds an interesting dimension that elevates an anatomical study to one that has clinical potential. Clinical Relevance: The established target zone gives a precise location for where the relationship between the deep band of the lateral PA and the lateral plantar nerve exists when evaluating the foot. The target zone provides a potential springboard for future investigations concerning said relationship clinically.

Crossing over with Rubén Blades

1991 ◽  
Vol 44 (2) ◽  
pp. 301-323 ◽  
Author(s):  
Don Michael Randel
Keyword(s):  
Puerto Rico ◽  
Popular Music ◽  
English Language ◽  
Crossing Over ◽  
Hollywood Films ◽  
Ways Of Thinking ◽  
American Popular Music ◽  
Ruben Blades ◽  
Relationship Of ◽  
The Relationship

Having won two Grammy Awards, attracted considerable attention in the English-language media, and appeared in several Hollywood films, Latin popular singer Rubén Blades has been much discussed as a crossover, that is, as an artist who, with a well-defined audience (in this case Hispanic), produces work that appeals in addition to another audience (here the audience for mainstream American popular music). El Gran Combo de Puerto Rico, in contrast, continues to appeal to its traditional Hispanic audience and remains the undisputed leader in popularity with that audience. A comparison of a piece by El Gran Combo with one by Blades suggests ways of thinking about the relationship of both to their audiences and to each other and ways in which musicology might approach such questions in specifically musical terms. Blades is seen not to be crossing over from one audience to another but to represent transformations in his Hispanic audience, which is itself crossing over to become increasingly imbued with Anglo culture while remaining rooted in its own traditions.

scholarly journals THE RELATIONSHIP OF CHIASMATA AND CROSSING OVER IN LILIUM FORMOSANUM

Genetics ◽  
1955 ◽  
Vol 40 (6) ◽  
pp. 850-873
Author(s):  
Spencer W Brown ◽  
Daniel Zohary
Keyword(s):  
Crossing Over ◽  
Relationship Of ◽  
The Relationship ◽  
Lilium Formosanum

scholarly journals The role of the ameiotic1 gene in the initiation of meiosis and in subsequent meiotic events in maize.

Genetics ◽  
1993 ◽  
Vol 135 (4) ◽  
pp. 1151-1166 ◽  
Author(s):  
I Golubovskaya ◽  
Z K Grebennikova ◽  
N A Avalkina ◽  
W F Sheridan
Keyword(s):  
Meiotic Division ◽  
Higher Plants ◽  
Gene Interaction ◽  
Microtubule Organizing Center ◽  
Spindle Fiber ◽  
Chromosome Synapsis ◽  
Organizing Center ◽  
Relationship Of ◽  
The Relationship

Abstract Understanding the initiation of meiosis and the relationship of this event with other key cytogenetic processes are major goals in studying the genetic control of meiosis in higher plants. Our genetic and structural analysis of two mutant alleles of the ameiotic1 gene (am1 and am1-praI) suggest that this locus plays an essential role in the initiation of meiosis in maize. The product of the ameiotic1 gene affects an earlier stage in the meiotic sequence than any other known gene in maize and is important for the irreversible commitment of cells to meiosis and for crucial events marking the passage from premeiotic interphase into prophase I including chromosome synapsis. It appears that the period of ameiotic1 gene function in meiosis at a minimum covers the interval from some point during premeiotic interphase until the early zygotene stage of meiosis. To study the interaction of genes in the progression of meiosis, several double meiotic mutants were constructed. In these double mutants (i) the ameiotic1 mutant allele was brought together with the meiotic mutation (afd1) responsible for the fixation of centromeres in meiosis; and with the mutant alleles of the three meiotic genes that control homologous chromosome segregation (dv1, ms43 and ms28), which impair microtubule organizing center organization, the orientation of the spindle fiber apparatus, and the depolymerization of spindle filaments after the first meiotic division, respectively; (ii) the afd1 mutation was combined with two mutations (dsy1 and as1) affecting homologous pairing; (iii) the ms43 mutation was combined with the as1, the ms28 and the dv1 mutations; and (iv) the ms28 mutation was combined with the dv1 mutation and the ms4 (polymitotic1) mutations. An analysis of gene interaction in the double mutants led us to conclude that the ameiotic1 gene is epistatic over the afd1, the dv1, the ms43 and the ms28 genes but the significance of this relationship requires further analysis. The afd gene appears to function from premeiotic interphase throughout the first meiotic division, but it is likely that its function begins after the start of the ameiotic1 gene expression. The afd1 gene is epistatic over the two synaptic mutations dsy1 and as1 and also over the dv1 mutation. The new ameiotic*-485 and leptotene arrest*-487 mutations isolated from an active Robertson's Mutator stocks take part in the control of the initiation of meiosis.

scholarly journals The relationship of homologous synapsis and crossing over in a maize inversion.

Genetics ◽  
1994 ◽  
Vol 137 (1) ◽  
pp. 281-288 ◽  
Author(s):  
M P Maguire ◽  
R W Riess
Keyword(s):  
Electron Micrographs ◽  
Crossing Over ◽  
Inverted Region ◽  
Recombination Nodule ◽  
Recombination Nodules ◽  
Reciprocal Recombination ◽  
Relationship Of ◽  
The Relationship

Abstract Frequency of homologous synapsis at pachytene for a relatively short heterozygous inversion was compared to the frequency of crossover occurrence within the inversion and to the frequency of the presence of a recombination nodule within the homologously synapsed inverted region. Crossover frequencies were estimated from bridge-fragment frequencies at anaphase I and anaphase II. Recombination nodules (RNs) were observed in electron micrographs. Results show very similar frequencies of homologous synapsis and the occurrence of reciprocal recombination within the inverted region, consistent with the interpretation that establishment of homologous synapsis in this case is related to at least commitment to the form of resolution of crossover intermediates which gives rise to reciprocal recombination, not conversion only, events. An RN was generally found at pachytene in homologously synapsed inverted regions.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

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