Characterization of sequences associated with position-effect variegation at pericentric sites in Drosophila heterochromatin.

abstract：:To structurally dissect mitotic chromosomes, we aim to position along the folded chromatin fiber proteins involved in long-range order, such as topoisomerase IIalpha (topoIIalpha) and condensin. Immuno-electron microscopy (EM) of thin-sectioned chromosomes is the method of choice toward this goal. A much-improved immu...

journal_title：Chromosoma

authors： Maeshima K,Eltsov M,Laemmli UK

更新日期：2005-11-01 00:00:00

abstract：:A system has been developed using a microscope photometer to measure the DNA content of individual chromosomes. After correcting for the systematic and statistical errors the measured values are highly reproducible. Data are presented of measurements of human Y chromosomes from a cytogenetically normal population. Whe...

journal_title：Chromosoma

authors： Wall WJ,Butler LJ

更新日期：1989-01-01 00:00:00

abstract：:Meiotic prophase in Schizosaccharomyces pombe is characterized by striking nuclear movements and the formation of linear elements along chromosomes instead of tripartite synaptonemal complexes. We analysed the organization of nuclei and microtubules in cells of fission yeasts undergoing sexual differentiation. S. japo...

journal_title：Chromosoma

authors： Svoboda A,Bähler J,Kohli J

更新日期：1995-11-01 00:00:00

abstract：:Metaphase chromosomes prepared from colcemid-treated mouse L929 cells by non-ionic detergent lysis exhibit distinct heterochromatic centromere regions and associated kinetochores when viewed by whole mount electron microscopy. Deoxyribonuclease I treatment of these chromosomes results in the preferential digestion of ...

journal_title：Chromosoma

authors： Rattner JB,Krystal G,Hamkalo BA

更新日期：1978-04-25 00:00:00

abstract：:Micronuclei are extra-nuclear bodies mainly derived from ana-telophase lagging chromosomes/chromatins (LCs) that are not incorporated into primary nuclei at mitotic exit. Unlike primary nuclei, most micronuclei are enclosed by nuclear envelope (NE) that is highly susceptible to spontaneous and irreparable rupture. Rup...

journal_title：Chromosoma

authors： Guo X,Dai X,Wu X,Zhou T,Ni J,Xue J,Wang X

更新日期：2020-12-01 00:00:00

abstract：:We have used the polymerase chain reaction (PCR) technique to search the Drosophila melanogaster genome for the presence of sequences with homology to mammalian and yeast centromeric DNA. Using primers based on the human CENP-B box present in alpha-satellite DNA and part of the Saccharomyces cerevisiae CDEIII centrome...

journal_title：Chromosoma

authors： Coelho PA,Nurminsky D,Hartl D,Sunkel CE

更新日期：1996-10-01 00:00:00

abstract：:The localization of DNA in the condensed interphase chromosomes of Euglena was determined by immunoelectron microscopy. Deposits of gold particles that coincided with the localization of DNA followed threads that corresponded to the chromatin fibers. The threads were 55-80nm in diameter and were assumed to be supersol...

journal_title：Chromosoma

authors： Ueda K,Hayashi-Ishimaru Y

更新日期：1996-01-01 00:00:00

abstract：:Aedes aegypti spermatocytes were reconstructed from electron micrographs. The species has tight somatic pairing of the chromosomes, and there are therefore no classical leptotene and zygotene stages, but rather a gradual transition from somatic pairing to meiotic pairing (= pachytene). The term "prepachytene" has been...

journal_title：Chromosoma

authors： Wandall A,Svendsen A

更新日期：1985-01-01 00:00:00

abstract：:The 17 kDa human autoantigen designated CENP-A is a centromere specific histone. We show here that CENP-A is present in tissue of bovine origin, and that it is quantitatively retained in mature spermatozoa. This result is striking, as a prominent feature of spermatogenesis in mammals is the replacement of most somatic...

journal_title：Chromosoma

authors： Palmer DK,O'Day K,Margolis RL

更新日期：1990-12-01 00:00:00

abstract：:It is reported that chromatin can be prepared from highly purified polytene nuclei from the salivary glands of third instar larvae of Drosophila hydei; such chromatin differs from that of diploid nuclei mainly by deficiencies in certain nonhistone chromosomal proteins. It is suggested that these proteins are important...

journal_title：Chromosoma

authors： Elgin SC,Boyd JB

更新日期：1975-01-01 00:00:00

abstract：:Replication times for all important chromosome bands, of both types R and Q (277 structures) are analysed. The R-bands form a group of structures whose DNA replicates during the early S-phase, while the DNA situated in the Q-bands replicates during the late S-phase. There may not exist overlapping between replication ...

journal_title：Chromosoma

authors： Dutrillaux B,Couturier J,Richer CL,Viegas-Péquignot E

更新日期：1976-10-12 00:00:00

abstract：:By using the optical properties of birefringence of DNA, the arrangement of these molecules has been studied in Dinoflagellate chromosomes and Dipteran polytene chromosomes. These latter are used, here, as a reference material. These observations have been made under a polarizing microscope on intact and stretched chr...

journal_title：Chromosoma

authors： Livolant F

更新日期：1978-08-21 00:00:00

abstract：:Triplet conjugation occurs frequently when three different mating types of T. thermophila are mixed under appropriate conditions. Genetic studies show that fertilization is usually tripolar, with each conjugant contributing a pronucleus to one mate and receiving a pronucleus from the other. Triplets are less common an...

journal_title：Chromosoma

authors： Preparata RM,Nanney DL

更新日期：1977-03-07 00:00:00

abstract：:Retroviruses have the ability to integrate into the genome of their host, in many cases with little apparent sequence or site specificity. However, relatively few studies have addressed more general features of chromosomal integration. In this study we directly visualized the chromosomal organization of three represen...

journal_title：Chromosoma

authors： Taruscio D,Manuelidis L

更新日期：1991-12-01 00:00:00

abstract：:In 1906, the Spanish neurobiologist Santiago Ramón y Cajal was awarded the Nobel Prize in Physiology or Medicine in recognition of his work on the structure of neurons and their connections. Cajal is commonly regarded as the father of modern neuroscience. What is less well known is that Cajal also had a great interest...

journal_title：Chromosoma

authors： Lafarga M,Casafont I,Bengoechea R,Tapia O,Berciano MT

更新日期：2009-08-01 00:00:00

abstract：:Nucleosome assembly involves deposition of a heterotetramer of histones H3/H4 onto DNA followed by two heterodimers of histones H2A/H2B. Cycles of nucleosome assembly and disassembly are essential to cellular events such as replication, transcription, and DNA repair. After synthesis in the cytoplasm, histones are shut...

journal_title：Chromosoma

authors： Mousson F,Ochsenbein F,Mann C

更新日期：2007-04-01 00:00:00

abstract：:Minute elements detected in Megaselia scalaris (Phoridae, Diptera) lack chromosome arms but carry centromeres and possess kinetochore microtubules in mitosis as well as in meiosis. These centromere-like elements (CLEs) were present in two geographically independent strains of the fly. This indicates that their origin ...

journal_title：Chromosoma

authors： Wolf KW,Mertl HG,Traut W

更新日期：1991-11-01 00:00:00

abstract：:The Bacillus subtilis phage phi 29 DNA polymerase, involved in protein-primed viral DNA replication, contains several amino acid consensus sequences common to other eukaryotic-type DNA polymerases. Using site-directed mutagenesis, we have studied the functional significance of a C-terminal conserved region, represente...

journal_title：Chromosoma

authors： Blasco MA,Esteban JA,Méndez J,Blanco L,Salas M

更新日期：1992-01-01 00:00:00

abstract：:By means of a cytological technique involving 5-bromodeoxyuridine, acridine orange, and fluorescence microscopy, the asynchronously replicating, hence genetically inactivated, X chromosome was identified in 6- to 8-day embryos from female mice heterozygous for Searle's translocation T(X;16)16H (abbreviated as T16H) ma...

journal_title：Chromosoma

authors： Takagi N

更新日期：1980-01-01 00:00:00

abstract：:We describe a method of mapping genes or transcripts on polytene chromosomes by transmission electron microscopy. We present several applications which illustrate that, in favorable cases, the method has a resolution of ca. 10 kg, and that high resolution mapping of hybridization sites relative to bands and puffs can ...

journal_title：Chromosoma

authors： Kress H,Meyerowitz EM,Davidson N

更新日期：1985-01-01 00:00:00

abstract：:In the XY pachytene spermatocyte, the sex chromosomes do not synapse except for the pseudoautosomal region and become transcriptionally silenced. It has been suggested that the meiotic silencing of unsynapsed chromatin (MSUC) also occurs in oocytes. In the XY sex-reversed female mouse, the sex chromosomes fail to pair...

journal_title：Chromosoma

authors： Taketo T,Naumova AK

更新日期：2013-10-01 00:00:00

abstract：:Cyclins, as regulatory partners of cyclin-dependent kinases (CDKs), control the switch-like cell cycle transitions that orchestrate orderly duplication and segregation of genomes. Compared to mitosis, relatively little is known about how cyclin-CDK complexes control meiosis, the specialized cell division that generate...

journal_title：Chromosoma

authors： Karasu ME,Keeney S

更新日期：2019-09-01 00:00:00

abstract：:A method is described for excising by a glass knife single bands of isolated polytene chromosomes of the salivary glands of Chironomus tentans larvae. DNA strands were isolated from cut-out bands and their contour lengths were determined on electron micrographs. The mean contour length of DNA strands isolated from the...

journal_title：Chromosoma

authors： Frey M,Koller T,Lezzi M

更新日期：1982-01-01 00:00:00

abstract：:In Xenopus laevis eight tRNA genes are located in a 3.18 kb tandemly repeated unit. There are 150 copies of the unit at a single locus near the long arm telomere of one of the acrocentric chromosomes in the 14-17 group. Two additional classes of tRNA gene-containing repeats have been isolated (defined by clones p3.1 a...

journal_title：Chromosoma

authors： Narayanswami S,Doering JL,Fokta FJ,Rosenthal DS,Nguyen TN,Hamkalo BA

更新日期：1995-10-01 00:00:00

abstract：:The ability to reproduce is a major trait of living organisms. This ability is carried out by specialized reproductive cells-gametes. In mammals, gametes develop through a unique developmental pathway. Extensive changes in the epigenome of gametes occur during embryonic development. With birth, gametes continue to mat...

journal_title：Chromosoma

authors： Wasserzug-Pash P,Klutstein M

更新日期：2019-09-01 00:00:00

abstract：:Mechanisms of chromosome condensation and segregation during the first meiotic division are not well understood. Resolution of recombination events to form chiasmata is important, for it is chiasmata that hold homologous chromosomes together for their oppositional orientation on the meiotic metaphase spindle, thus ens...

journal_title：Chromosoma

authors： Cobb J,Miyaike M,Kikuchi A,Handel MA

更新日期：1999-12-01 00:00:00

abstract：:DNA topology in histone- and protamine-depleted nuclei (nucleoids) from somatic cells, sperm, and spermatogenic cells was studied to determine if the superhelical configuration of DNA looped domains is altered during spermatogenesis. The expansion and contraction of nucleoid DNA was measured with a fluorescence micros...

journal_title：Chromosoma

authors： Risley MS,Einheber S,Bumcrot DA

更新日期：1986-01-01 00:00:00

abstract：:Ki-67 protein has been widely used as a proliferation marker for human tumor cells for decades. In recent studies, multiple molecular functions of this large protein have become better understood. Ki-67 has roles in both interphase and mitotic cells, and its cellular distribution dramatically changes during cell cycle...

journal_title：Chromosoma

authors： Sun X,Kaufman PD

更新日期：2018-06-01 00:00:00

abstract：:Spermatogenic cells of the mouse have been separated by gravity sedimentation using a modification of a previously published method. Details are given for the collection of purified samples of specific meiotic stages and for the collection of labelled cell fractions following injection of 3H-thymidine. Suppression of ...

journal_title：Chromosoma

authors： Chandley AC,Hotta Y,Stern H

更新日期：1977-07-08 00:00:00

abstract：:In the parasitic wasp Nasonia vitripennis, certain males carry a B chromosome, called PSR (paternal sex ratio), which causes the compaction and subsequent loss of the paternal chromosomes in fertilized eggs. Because Nasonia are haplo-diploid, this leads to the production of all-male broods. Three families (PSR2, PSR18...

journal_title：Chromosoma

authors： Eickbush DG,Eickbush TH,Werren JH

更新日期：1992-08-01 00:00:00