scholarly journals Native Salivary Chromosomes of Drosophila melanogaster: Retrospect and Prospect

1985 ◽  
Vol 38 (1) ◽  
pp. 1 ◽  
Author(s):  
Ronald J Hill
Keyword(s):  
Drosophila Melanogaster ◽  
Light Microscope ◽  
Background Level ◽  
Nuclear Proteins ◽  
Dna Conformation ◽  
Genetic Loci ◽  
Linear Arrays ◽  
Torsional Strain ◽  
Z Dna ◽  
First Time

A method has been developed which, for the first time, allows the preparation of mappable cytological spreads of salivary chromosomes from D. melanogaster without exposure to acid fixatives. These isolated native chromosomes show the best preservation of ultrastructure observed to date-ribonucleoprotein particles may be seen to be organized in linear arrays in transcriptionally active puffs and the repeating nucleosome module is present. Native salivary chromosomes are proving useful for the localization of nuclear proteins both at the light microscope and ultrastructural levels. They display only background-level binding of antibodies specific for the Z-DNA conformation. However, Z-DNA immunoreactivity is activated by exposure to acid fixative, first in interbands and then in bands. The Z-conformation in the chromosomes is held in place by elastic torsional strain which appears in the DNA following acid fixation. Native D. melanogaster salivary chromosomes offer promise for enabling the probing of the chromatin of known genetic loci for properties dependent on the preservation of macromolecular integrity.

Panagrellus levitatus sp. n. (Rhabditida: Panagrolaimidae), a nematode suppressing Drosophila melanogaster in laboratory cultures

Nematology ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 285-297 ◽  
Author(s):  
Elena Ivanova ◽  
Ksenia Perfilieva ◽  
Sergei Spiridonov
Keyword(s):  
Drosophila Melanogaster ◽  
New Species ◽  
Nematode Species ◽  
Laboratory Culture ◽  
Ssu Rdna ◽  
Lsu Rdna ◽  
Red Palm Weevil ◽  
Rdna Sequences ◽  
Mass Reproduction ◽  
First Time

A new nematode species recovered from the laboratory culture ofDrosophila melanogasteris described and illustrated. The mass reproduction ofPanagrellus levitatussp. n. in the fly culture occurred several times and resulted in a significant reduction of the fly population. Nematode outbreaks happened after the introduction ofD. melanogasterto the culture from natural sources. The new species is morphologically similar toP. ulmi. Partial LSU rDNA and SSU rDNA sequences were obtained and subjected to phylogenetic analysis that demonstrated the affinity of the new species withPanagrellussp. ‘MC2014’ from a red palm weevil. For the first time, the dauer juveniles ofPanagrelluswere described.

Molecular Cloning and Expression of Stromalin Protein from Drosophila melanogaster: Homologous to Mammalian Stromalin Family of Nuclear Proteins

1998 ◽  
Vol 17 (8) ◽  
pp. 699-706 ◽  
Author(s):  
ANA VALDEOLMILLOS ◽  
RICARDO VILLARES ◽  
JOSÉ M. BUESA ◽  
SERGIO GONZÁLEZ-CRESPO ◽  
CARLOS MARTÍNEZ-A. ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Cloning ◽  
Cloning And Expression ◽  
Nuclear Proteins

scholarly journals Genetic study of motor functions in Drosophila melanogaster

2012 ◽  
Vol 10 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Sergey A Fedotov ◽  
Julia V Bragina ◽  
Nataliya G Besedina ◽  
Larisa V Danilenkova ◽  
Elena A Kamysheva ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Motor Activity ◽  
Genomic Dna ◽  
Molecular Mechanisms ◽  
Central Pattern Generators ◽  
Courtship Song ◽  
P Element ◽  
Rhythmic Motor ◽  
Pattern Generators ◽  
First Time

To investigate molecular mechanisms of central pattern generators (CPG s) functioning, we carried out a screening of collection of Drosophila P-insertional mutants for strong deviations in locomotion and courtship song. In 21 mutants, the site of the P-insertion was localized by sequencing of the fragments of genomic DNA flanking the P-element. Bioinformational analysis revealed a list of candidate genes, potential players in development and functioning of CPG s. Possible involvement of certain identified genes in rhythmic motor activity is suggested for the first time (CG15630, Map205).

scholarly journals Morphology and ecology of Thalassiosira Cleve (Bacillariophyta) species rarely recorded in Brazilian coastal waters

2009 ◽  
Vol 69 (4) ◽  
pp. 1059-1071 ◽  
Author(s):  
M. Garcia ◽  
C. Odebrecht
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Water Temperature ◽  
Wide Temperature Range ◽  
Coastal Waters ◽  
Light Microscope ◽  
Temperature Range ◽  
The World ◽  
First Time ◽  
Scanning Electron

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 µm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Patos, were studied in cleaned material using the Axiovert Zeiss LM and Jeol 6060 SEM. Water temperature and salinity of samples and six species are presented: Thalassiosira endoseriata, T. hendeyi, T. lundiana, T. minuscula, T. oceanica and T. wongii. Two species, Thalassiosira hendeyi and T. endoseriata were the most common being observed in all seasons at Cassino Beach in a wide temperature range (10-26 ºC), while only sporadically in the estuary of Lagoa dos Patos. Thalassiosira endoseriata, T. lundiana, T. oceanica and T. wongii are for the first time reported in Brazilian coastal waters. The latter two species, rarely recorded in the world, are fully illustrated based on Brazilian material.

Taxonomic studies in the genus Haplanthodes (Acanthaceae)

Phytotaxa ◽  
2021 ◽  
Vol 516 (3) ◽  
Author(s):  
PRADIP VIKRAM DESHMUKH ◽  
SIDDHARTHAN SURVESWARAN ◽  
RAMCHANDRA DNYANOBA GORE ◽  
MANOJ MADHWANAND LEKHAK
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Pollen Grains ◽  
Prolate Spheroidal ◽  
New Variety ◽  
Exine Ornamentation ◽  
Taxonomic Studies ◽  
First Time ◽  
Scanning Electron

The endemic Indian genus Haplanthodes (Acanthaceae) is revised. Four species, viz. H. neilgherryensis, H. plumosa, H. tentaculata and H. verticillata and a new variety, H. neilgherryensis var. toranganensis are recognized. Lectotype is designated for Haplanthodes, Haplanthus plumosus and H. verticillaris. The nomenclature of the Linnaean name Ruellia tentaculata is also discussed. Micromorphology of seed using light microscope (LM) and scanning electron microscope (SEM) is observed for the first time, and two types, reticulate and micro papillate, have been recognized based on surface sculpturing pattern. The genus differs from the related genera Andrographis and Haplanthus by distinctly two grooved seeds with hygroscopic hairs. Pollen grains of the genus are oblate or prolate spheroidal, distinctly triangular, trizonocolporate with reticulate exine ornamentation.

scholarly journals New and rare species of Volvocaceae (Chlorophyta) in the Polish phycoflora

2013 ◽  
Vol 82 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Ewa A. Dembowska
Keyword(s):  
Rare Species ◽  
Light Microscope ◽  
Aquatic Ecosystems ◽  
Oxbow Lakes ◽  
Vistula River ◽  
Photographic Documentation ◽  
Pandorina Morum ◽  
1960S And 1970S ◽  
The 1960S ◽  
First Time

Seven species of Volvocaceae were recorded in the lower Vistula River and its oxbow lakes, including <em>Pleodorina californica</em> for the first time in Poland. Three species – <em>Eudorina cylindrica</em>, <em>E. illinoisensis</em> and <em>E. unicocca</em> – were found in the Polish Vistula River in the 1960s and 1970s, as well as at present. They are rare species in the Polish aquatic ecosystems. Three species are common both in the oxbow lakes and in the Vistula River: <em>Eudorina elegans</em>, <em>Pandorina morum</em> and <em>Volvox aureus</em>. New and rare Volvocaceae species were described in terms of morphology and ecology; also photographic documentation (light microscope microphotographs) was completed.

Spore morphology of Selaginella (Selaginellaceae) from China and its systematic significance

Phytotaxa ◽  
2015 ◽  
Vol 237 (1) ◽  
pp. 1 ◽  
Author(s):  
Xin-Mao Zhou ◽  
Li-Jü Jiang ◽  
Liang Zhang ◽  
Xin-Fen Gao ◽  
Zhao-Rong He ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Morphological Characteristics ◽  
Spore Morphology ◽  
Systematic Significance ◽  
First Time ◽  
Scanning Electron

Using light microscope (LM) and scanning electron microscope (SEM), the megaspores and microspores of 77 samples representing ca. 70 species of Selaginella from China are observed. Combing previous studies, the spore morphology of nearly all documented Selaginella species from China were reviewed. Based on the morphological characteristics in megaspores and/or microspores, we divided the spores of Chinese species into 15 types and three types are further divided into various subtypes. Each type and subtype are described in detail and a key to the types and subtypes of spores is given. For the first time, the systematic significance of microspores of Selaginella are discussed, and the results indicate that microspores of Selaginella are significant in the systematics of Selaginella. Some important morphological characteristics in spores (e.g., color, micro-sculpture, size, etc.), often been neglected in previous studies, are introduced. Some spore-morphological synapomorphies of the clades and subclades, identified by recent molecular work (Zhou et al. 2015a), are well established. Using the spore morphology, the delimitation of some taxonomically difficult species in Selaginella is assessed.

Effects of the O2' hydroxyl group on Z-DNA conformation: structure of Z-RNA and (araC)-[Z-DNA]

Biochemistry ◽  
1989 ◽  
Vol 28 (12) ◽  
pp. 4923-4928 ◽  
Author(s):  
Mai Kun Teng ◽  
Yen Chywan Liaw ◽  
Gijs A. Van der Marel ◽  
Jacques H. Van Boom ◽  
Andrew H. J. Wang
Keyword(s):  
Dna Conformation ◽  
Hydroxyl Group ◽  
Z Dna

First Evidence of Flux Transfer Events Caused by Mangetosheath Jets

2020 ◽  
Author(s):  
Simon Thor ◽  
Anita Kullen ◽  
Tomas Karlsson ◽  
Savvas Raptis
Keyword(s):  
Formation Process ◽  
Statistical Study ◽  
Dynamic Pressure ◽  
Background Level ◽  
Jet Formation ◽  
Flux Transfer Events ◽  
Reconnection Region ◽  
Close Proximity ◽  
Flux Transfer ◽  
First Time

&lt;p&gt;Magnetosheath jets are local enhancements of dynamic pressure above the background level. Hietala et al. (2018) recently presented observational evidence of a jet collision with the magnetopause causing magnetic field line reconnection. In the present study, we show data which, for the first time, strongly indicates that magnetosheath jets can even create localized transient reconnection events, so-called flux transfer events (FTEs).&lt;/p&gt;&lt;p&gt;FTEs are commonly observed in cascades with an average separation time of 8-10 minutes, but may also appear as isolated events. Despite the fact that FTEs have gained major attraction during recent years, the formation process of FTEs is not yet fully understood. We showed in a recent statistical study (Kullen, Thor, and Karlsson; 2019) that isolated FTEs and FTE cascades occur during different IMF conditions and are differently distributed along the magnetopause. The results of the statistical study strongly suggest that the majority of the FTEs formed along the expected reconnection region for each respective IMF condition. However, for a subset of isolated FTEs, we proposed a different formation process. These events may have been caused by magnetosheath jets, as they occur during IMF conditions favorable for jet formation. Simulation results by Karimabadi et al. (2014) has shown that such a creation mechanism is possible. In his simulation, a magnetosheath jet collides with the magnetopause, creating an FTE.&lt;/p&gt;&lt;p&gt;In the present investigation, FTEs that may have been caused by magnetosheath jets were identified. To achieve this, we examined measurements from all four Cluster satellites, and searched for magnetosheath jets that appear in close proximity to FTEs listed in Wang et al. (2005)&amp;#8217;s FTE list. Our results show that approximately 15% of isolated FTEs appear in the vicinity of jets. These FTEs are further examined based on IMF and location across the magnetopause. For two of the FTEs, the associated jet appears close to the magnetopause. We present a detailed data analysis of these two events and discuss a possible formation mechanism for the FTEs, as there is strong evidence that the two FTEs are indeed caused by jets.&lt;/p&gt;

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