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 used for the transitory stage. The first visible sign of impending meiosis was a reorganization of the chromatin, which resulted in the formation of spaces (synaptic spaces) in the chromatin, about the width of the synaptonemal complexes (SCs). Diffuse material, possibly precursor material for the SC, was present in the spaces. Later short pieces of complex were formed throughout the nucleus. Late prepachytene, pachytene, and diplotene complexes were reconstructed. Each chromosome occupied a separate region of the nucleus. The complexes became progressively shorter from prepachytene (maximum complement length 289 micron) to diplotene (175 micron). The thickness of the SCs increased from prepachytene to pachytene and probably decreased again during diplotene. At the beginning of diplotene the lateral elements (LEs) separated, and the single LEs became two to three times thicker than the LEs of the SC. The centromeres were at all stages attached to the nuclear membrane, whereas the telomeres were free in the nucleoplasm during pachytene and diplotene. A heterochromatic marker was present on chromosome 1 near the sex determining locus, and a diffuse marker on chromosome 3 near the nucleolus organizer region. After breakdown of the complexes, polycomplexes were present in the nucleus.
journal_name
Chromosomajournal_title
Chromosomaauthors
Wandall A,Svendsen Adoi
10.1007/BF00329808subject
Has Abstractpub_date
1985-01-01 00:00:00pages
254-64issue
4eissn
0009-5915issn
1432-0886journal_volume
92pub_type
杂志文章相关文献
CHROMOSOMA文献大全abstract::The X and Y chromosomes of the musk shrew are the two largest in the complement and they regularly form a single chiasma during meiosis. This chiasma is located in the short arms of the X and Y, both of which show partial C-banding at meiosis. The in vitro incorporation of 5-bromodeoxyuridine/tritiated thymidine durin...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00327596
更新日期:1986-01-01 00:00:00
abstract::The sub-division of S-phase in Syrian hamsters, on the basis of Brd/U/Hoechst 33258/Giemsa banding, has allowed a quantitative comparison of the replication of individual chromosome bands within defined subphases of S. This analysis has shown that in hamsters, as has been reported in humans, there are distinct pattern...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00286026
更新日期:1981-01-01 00:00:00
abstract::The mean DNA content of G2 macronuclei varies during the life cycle of the ciliate Tetrahymena thermophila. Early in the life cycle the mean is about 130 C; later it is about 94 C. In hybrids between strains A and B the decrease from 130 C to 94 C usually began after 60 fissions after conjugation. In B X B clones the ...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00327377
更新日期:1978-10-20 00:00:00
abstract::Recent data suggest that insulators organize chromatin architecture in the nucleus. The best characterized Drosophila insulator, found in the gypsy retrotransposon, contains 12 binding sites for the Su(Hw) protein. Enhancer blocking, along with Su(Hw), requires BTB/POZ domain proteins, Mod(mdg4)-67.2 and CP190. Inacti...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-016-0596-3
更新日期:2017-03-01 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
pub_type: 杂志文章
doi:10.1007/BF00319831
更新日期:1975-01-01 00:00:00
abstract::Metaphase chromosomes from cultured Chinese Hamster Ovary cells were labelled in suspension with a monoclonal antibody to histone 2B, counterstained with propidium iodide (PI) and analysed by flow cytometry. Contour plots of antibody binding (FITC fluorescence) against DNA content (PI fluorescence) revealed two discre...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00294783
更新日期:1987-01-01 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
pub_type: 杂志文章,评审
doi:10.1007/s00412-019-00704-w
更新日期:2019-09-01 00:00:00
abstract::Homologous chromosomes exchange genetic information through recombination during meiosis, a process that increases genetic diversity, and is fundamental to sexual reproduction. In an attempt to shed light on the dynamics of mammalian recombination and its implications for genome organization, we have studied the recom...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-016-0624-3
更新日期:2017-10-01 00:00:00
abstract::The DNA coding for 28 S and 18 S ribosomal RNA, including the spacer regions, has been isolated from calf (Bos taurus) thymus gland. The method used included shearing of the total DNA to a highly homogeneous size population, selective heat denaturation and S1 nuclease treatment to remove single stranded DNA. Repeated ...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00293439
更新日期:1976-10-12 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
pub_type: 杂志文章
doi:10.1007/BF00293158
更新日期:1985-01-01 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
pub_type: 杂志文章,评审
doi:10.1007/s00412-020-00741-w
更新日期:2020-12-01 00:00:00
abstract::Sister chromatids are physically connected by cohesin complexes. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic and meiotic spindle. In many species, cohesion between chromosome arms is partly dissolved in prophase of mitosis, whereas cohesion is protected at centromere...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-007-0139-z
更新日期:2008-04-01 00:00:00
abstract::Chromosome fibers isolated from lymphocyte nuclei and prepared for electron microscopy by techniques designed to preserve their native structure have a distinctly knobby appearance, suggesting that DNA and protein are not distributed evenly along the fiber axis. Individual knobs (superbeads) are arranged in tandem and...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00327030
更新日期:1977-07-18 00:00:00
abstract::Recent progress in elucidating the function of synaptonemal complex (SC) proteins and of cohesins in meiocytes made possible, in particular, through the analysis of mice deficient in SC or cohesin proteins has significantly enriched our understanding of how meiotic chromosome architecture is determined. Cohesins and t...
journal_title:Chromosoma
pub_type: 杂志文章,评审
doi:10.1007/s00412-006-0060-x
更新日期:2006-06-01 00:00:00
abstract::We characterized four meiotic mutants of the fission yeast Schizosaccharomyces pombe by live observation of nuclear movement. Nuclei were stained with either the DNA-specific fluorescent dye Hoechst 33342 or jellyfish green fluorescent protein (GFP) fused with the N-terminal portion of DNA polymerase alpha. We first f...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s004120050417
更新日期:2000-01-01 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
pub_type: 杂志文章,评审
doi:10.1007/s00412-018-0659-8
更新日期:2018-06-01 00:00:00
abstract::Chromosome segregation in primary spermatocytes of the crane fly Nephrotoma suturalis was studied after exposure to Colcemid at doses that did not completely inhibit spindle formation. Colcemid was added either to the medium in which larvae were cultured or to Tricine buffer in which isolated testes were incubated. Pa...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00291004
更新日期:1985-01-01 00:00:00
abstract::Internally consistent G-, Q- and R-banded karyotypes and idiograms for sheep chromosomes at the 422-band level of resolution are presented. These were derived by sequential Q- to G-staining, and sequential Q- to R-staining of prometaphase spreads prepared from sheep with normal and Robertsonian chromosomes. The fused ...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF02510040
更新日期:1996-07-01 00:00:00
abstract::Microspore culture stimulates immature pollen grains to develop into plants via tissue culture and is used routinely in many crop species to produce "doubled haploids": homozygous, true-breeding lines. However, microspore culture is also often used on material that does not have stable meiosis, such as interspecific h...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-019-00720-w
更新日期:2019-12-01 00:00:00
abstract::DNA double-strand breaks arise accidentally upon exposure of DNA to radiation and chemicals or result from faulty DNA metabolic processes. DNA breaks can also be introduced in a programmed manner, such as during the maturation of the immune system, meiosis, or cancer chemo- or radiotherapy. Cells have developed a vari...
journal_title:Chromosoma
pub_type: 杂志文章,评审
doi:10.1007/s00412-017-0658-1
更新日期:2018-06-01 00:00:00
abstract::Very few of the middle repetitive DNA sequences found in Drosophila melanogaster are present in all of the species of the D. melanogaster subgroup. One member of the subgroup, D. erecta, lacks most of the families of repetitive elements from D. melanogaster (including copia and 412) but possesses many other families n...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00327329
更新日期:1983-01-01 00:00:00
abstract::Regulation of DNA replication is critical, and loss of control can lead to DNA amplification. Naturally occurring, developmentally regulated DNA amplification occurs in the DNA puffs of the late larval salivary gland giant polytene chromosomes in the fungus fly, Sciara coprophila. The steroid hormone ecdysone induces ...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-012-0395-4
更新日期:2013-03-01 00:00:00
abstract::Sugar beet (Beta vulgaris) chromosomes consist of large heterochromatic blocks in pericentromeric, centromeric, and intercalary regions comprised of two different highly abundant DNA satellite families. To investigate DNA methylation at single base resolution at heterochromatic regions, we applied a method for strand-...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-011-0325-x
更新日期:2011-08-01 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
pub_type: 杂志文章
doi:10.1007/BF00330371
更新日期:1978-08-21 00:00:00
abstract::The best-studied Drosophila insulator complex consists of two BTB-containing proteins, the Mod(mdg4)-67.2 isoform and CP190, which are recruited cooperatively to chromatin through interactions with the DNA-binding architectural protein Su(Hw). While Mod(mdg4)-67.2 interacts only with Su(Hw), CP190 interacts with many ...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/s00412-017-0645-6
更新日期:2018-03-01 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
pub_type: 杂志文章
doi:10.1007/BF00330410
更新日期:1977-03-07 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
pub_type: 杂志文章
doi:10.1007/BF00286046
更新日期:1977-07-08 00:00:00
abstract::Anaphase lagging of autosomes was observed in 6.1 +/- 5.4% of the primary spermatocytes in untreated larvae of the crane fly, Nephrotoma suturalis. Lagging was induced by exposure of larvae to 6 degrees C and during recovery at 22 degrees C from exposure to 0.2, 2, and 6 degrees C. The incidence of anaphase lag was ma...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00330776
更新日期:1982-01-01 00:00:00
abstract::In situ hybridization of labeled DNA of four mobile dispersed genetic elements (mdg), isolated from D. melanogaster and C. virilis genomes, with polytene chromosomes of the larvae of several Drosophila species has been carried out. The data show that the mdg elements exhibit a high degree of species specificity. The s...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00330360
更新日期:1982-01-01 00:00:00
abstract::Male hybrids of the cross D. azteca X D. athabasca are larger (hybrid giant males) than their parents, whereas hybrid females are of the same size as the parental species. Microspectrophotometric measurements have shown that the larval polytene salivary gland chromosomes of hybrid giant males undergo one more endorepl...
journal_title:Chromosoma
pub_type: 杂志文章
doi:10.1007/BF00295210
更新日期:1976-09-10 00:00:00