The Lampbrush Chromosomes ofRana EsculentaL. (Amphibia — Anura)
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چکیده
منابع مشابه
The organization of transcription on lampbrush chromosomes.
The meiotic lampbrush chromosomes of amphibian oocytes display readily distinguishable regions of transcription (lateral loops) which extend from axial condensates of chromatin (chromomeres). The chromomeres contain most of the chromosomal ENA which, along with histone, is tightly compacted as regular arrays of DNP. Many RNA transcripts are generated on the lateral loops, and heterogeneous non-...
متن کاملLampbrush chromosomes of the chicken, Gallus domesticus
We examined lampbrush chromosomes (LBC) prepared from chicken oocytes of 1-3-mm diam using both light and electron microscopy. Both macro- and microchromosomes form LBC with morphologies very similar to the well known newt and salamander LBC. In chicken LBC typical loops have a contour length of approximately 15 microns, although some loops range up to 50 microns. Multiple transcription units a...
متن کاملAn Electron Microscope Study of Lampbrush Chromosomes
Lampbrush chromosomes were isolated from germinal vesicles of oocytes from Necturus maculatus, Triturus viridescens, Pseudotriton montanus and Rana pipiens. After treatment of isolated nuclei with 10 per cent sucrose, chromosomes free of nuclear sap are obtained for examination in either the light microscope or in the electron microscope. For electron microscopy the chromosomes were prepared ei...
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Lampbrush Chromosomes (LBCs) are present in the oocytes of birds, lower vertebrata and invertebrates during the prolonged prophase of the first meiotic division. Their name stems from their similarity to bottle brushes. Lampbrush chromosome of the early prophase is a bivalent, made up of two conjugating homologues. The axis of each homologous chromosome is formed by sister chromatids that are d...
متن کاملChromosome evolution in dendropsophini (Amphibia, Anura, Hylinae).
Dendropsophini is the most species-rich tribe within Hylidae with 234 described species. Although cytogenetic information is sparse, chromosome numbers and morphology have been considered as an important character system for systematic inferences in this group. Using a diversity of standard and molecular techniques, we describe the previously unknown karyotypes of the genera Xenohyla, Scarthyla...
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ژورنال
عنوان ژورنال: Caryologia
سال: 1972
ISSN: 0008-7114,2165-5391
DOI: 10.1080/00087114.1972.10796470