Relocalization of an 82-kDa protein from lampbrush loops into the nucleoskeleton during amphibian oogenesis

1990 ◽  
Vol 199 (3) ◽  
pp. 181-187
Author(s):  
Nicole Moreau ◽  
Nicole Angelier ◽  
Nicole Lautredou
Keyword(s):  
Lampbrush Loops

Single stranded nucleic acid binding structures on chicken lampbrush chromosomes

1995 ◽  
Vol 108 (4) ◽  
pp. 1391-1396
Author(s):  
I. Solovei ◽  
H. Macgregor ◽  
E. Gaginskaya
Keyword(s):  
Nucleic Acid ◽  
Structural Organization ◽  
Mrna Processing ◽  
Nucleic Acid Binding ◽  
Lampbrush Chromosomes ◽  
Cytological Evidence ◽  
Rna Transcripts ◽  
Physical Maps ◽  
Distinctive Morphology ◽  
Lampbrush Loops

In chicken oocytes, proteins of the K/J family or their analogs, such as are known to be involved in mRNA processing in humans, are closely associated with nascent C-rich RNA transcripts on the loops of lampbrush chromosomes. Using labelled single stranded nucleotide probes and an antibody to protein K, these C-rich transcripts have been mapped to six different pairs of lampbrush loops situated on 3 macrochromosomes, the sex bivalent (ZW) and certain microchromosomes. Each of these loop pairs has a distinctive morphology. The observations represent cytological evidence of the connection between K-proteins and C-rich RNA transcripts. Another structure, the spaghetti marker of macrochromosome II, also preferentially binds C-rich homonucleotides. This spaghetti marker has a highly distinctive fine structural organization that is quite unlike that of lampbrush loops. Its proteins are not recognised by antibodies to protein K. Homonucleotide binding loops are recommended as potentially extremely valuable as markers on physical maps of chicken chromosomes.

DNA clones and RNA transcripts of four lampbrush loops from the Y chromosome of Drosophila hydei

Cell ◽  
1983 ◽  
Vol 32 (1) ◽  
pp. 191-199 ◽  
Author(s):  
Eliezer Lifschytz ◽  
Dana Hareven ◽  
Aviva Azriel ◽  
Howard Brodsly
Keyword(s):  
Y Chromosome ◽  
Rna Transcripts ◽  
Drosophila Hydei ◽  
Lampbrush Loops

scholarly journals Association of nucleoplasmin with transcription products as revealed by immunolocalization in the amphibian oocyte.

1986 ◽  
Vol 103 (3) ◽  
pp. 683-690 ◽  
Author(s):  
N Moreau ◽  
N Angelier ◽  
M L Bonnanfant-Jais ◽  
P Gounon ◽  
P Kubisz
Keyword(s):  
Transcriptional Activity ◽  
Light And Electron Microscopy ◽  
Nuclear Proteins ◽  
Oocyte Nucleus ◽  
Actin Network ◽  
Previously Treated ◽  
Pleurodeles Waltlii ◽  
Chromosome Axis ◽  
Lampbrush Loops ◽  
Nuclear Content

The oocyte nucleus of Pleurodeles waltlii contains a major 32,000-mol-wt acidic protein which is called nucleoplasmin. Rabbit antibodies were raised against total nuclear proteins from Pleurodeles oocytes. Affinity-purified antibodies directed against nucleoplasmin were prepared using antigens bound to nitrocellulose paper. The specificity of the antibody was controlled on two-dimensional electrophoretic gels of nuclear proteins. The intranuclear distribution of nucleoplasmin was analyzed by indirect immunofluorescence and the immunogold technique in light and electron microscopy. The antibody was tested on a spread of the nuclear content prepared in the presence of calcium, on the nuclear content spread in the presence of phalloidin so that an actin network appeared, and on a spread of nuclei from oocytes previously treated by actinomycin D. In all cases, nucleoplasmin appeared to be localized on the lampbrush loops, i.e., on the sites of transcription and, more specifically, on the ribonucleoprotein (RNP) particles; this protein was also associated with the RNP particles of the nuclear sap (free or inserted in the actin network). Nucleoplasmin was localized on large RNP particles that appeared when transcription was blocked. We never found this protein on the chromosome axis. These results suggest that nucleoplasmin may play a role in transcriptional activity.

scholarly journals Assembly of Lampbrush Chromosomes from Sperm Chromatin

1998 ◽  
Vol 9 (4) ◽  
pp. 733-747 ◽  
Author(s):  
Joseph G. Gall ◽  
Christine Murphy
Keyword(s):  
Rna Polymerase Ii ◽  
Actinomycin D ◽  
Germinal Vesicle ◽  
Immunofluorescent Staining ◽  
Sperm Chromatin ◽  
Lampbrush Chromosomes ◽  
Pol Ii ◽  
Specific Proteins ◽  
Cis And Trans ◽  
Lampbrush Loops

We have examined the behavior of demembranated sperm heads when injected into the germinal vesicle (GV) of amphibian oocytes.Xenopus sperm heads injected into XenopusGVs swelled immediately and within hours began to stain with an antibody against RNA polymerase II (Pol II). Over time each sperm head became a loose mass of chromosome-like threads, which by 24–48 h resolved into individually recognizable lampbrush chromosomes (LBCs). Although LBCs derived from sperm are unreplicated single chromatids, their morphology and immunofluorescent staining properties were strikingly similar to those of the endogenous lampbrush bivalents. They displayed typical transcriptionally active loops extending from an axis of condensed chromomeres, as well as locus-specific “landmarks.” Experiments with [3H]GTP and actinomycin D demonstrated that transcription was not necessary for the initial swelling of the sperm heads and acquisition of Pol II but was required for maintenance of the lampbrush loops. Splicing was not required at any stage during formation of sperm LBCs. When Xenopus sperm heads were injected into GVs of the newt Notophthalmus, the resulting sperm LBCs displayed very long loops with pronounced Pol II axes, like those of the endogenous newt LBCs; as expected, they stained with antibodies against newt-specific proteins. Other heterologous injections, including sperm heads of the frog Rana pipiens and the zebrafish Danio rerio inXenopus GVs, confirm that LBCs can be derived from taxonomically distant organisms. The GV system should help identify both cis- and trans-acting factors needed to convert condensed chromatin into transcriptionally active LBCs. It may also be useful in producing cytologically analyzable chromosomes from organisms whose oocytes do not go through a typical lampbrush phase or cannot be manipulated by current techniques.

scholarly journals Mega-introns in the Dynein Gene DhDhc7(Y) on the Heterochromatic Y Chromosome Give Rise to the Giant Threads Loops in Primary Spermatocytes of Drosophila hydei

Genetics ◽  
2000 ◽  
Vol 154 (2) ◽  
pp. 759-769 ◽  
Author(s):  
Alexander M Reugels ◽  
Roman Kurek ◽  
Ulrich Lammermann ◽  
Hans Bünemann
Keyword(s):  
Satellite Dna ◽  
Transcription Unit ◽  
Drosophila Hydei ◽  
Y Chromosomes ◽  
Protein Encoding ◽  
Species Specific ◽  
Giant Size ◽  
Large Clusters ◽  
Fertility Genes ◽  
Lampbrush Loops

Abstract The heterochromatic Y chromosomes of several Drosophila species harbor a small number of male fertility genes (fertility factors) with several unusual features. Expression of their megabase-sized loci is restricted to primary spermatocytes and correlates with the unfolding of species-specific lampbrush loop-like structures resulting from huge transcripts mainly derived from clusters of loop-specific Y chromosomal satellites. Otherwise, there is evidence from genetic mapping and biochemical experiments that at least two of these loops, Threads in Drosophila hydei and kl-5 in D. melanogaster, colocalize with the genes for the axonemal dynein β heavy chain proteins DhDhc7(Y) and Dhc-Yh3, respectively. Here, we make use of particular Threads mutants with megabase-sized deletions for direct mapping of DhDhc7(Y)-specific exons among the large clusters of satellite DNA within the 5.1-Mb Threads transcription unit. PCR experiments with exon-specific primer pairs, in combination with hybridization experiments with exon- and satellite-specific probes on filters with large PFGE-generated DNA fragments, offer a simple solution for the long-lasting paradox between megabase-sized loops and protein-encoding transcription units; the lampbrush loops Threads and the DhDhc7(Y) gene are one and the same transcription unit, and the giant size of the DhDhc7(Y) gene as well as its appearance as a giant lampbrush loop are merely the result of transcription of huge clusters of satellite DNA within some of its 20 introns.

scholarly journals The Y Chromosomal Fertility Factor Threads in Drosophila hydei Harbors a Functional Gene Encoding an Axonemal Dynein β Heavy Chain Protein

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1363-1376 ◽  
Author(s):  
Roman Kurek ◽  
Alexander M Reugels ◽  
Karl Heinz Glaätzer ◽  
Hans Bünemann
Keyword(s):  
Heavy Chain ◽  
Gene Encoding ◽  
Chain Molecules ◽  
Sperm Tail ◽  
Fertility Factor ◽  
Putative Protein ◽  
Drosophila Hydei ◽  
Dynein Arms ◽  
Large Clusters ◽  
Lampbrush Loops

Abstract To understand the contradiction between megabase-sized lampbrush loops and putative protein encoding genes both associated with the loci of Y chromosomal fertility genes of Drosophila on the molecular level, we used PCR-mediated cloning to identify and isolate the cDNA sequence of the Y chromosomal Drosophila hydei gene DhDhc7(Y). Alignment of the sequences of the putative protein DhDhc7(Y) and the outer arm dynein β heavy chain protein DYH2 of Tripneustes gratilla shows homology over the entire length of the protein chains. Therefore the proteins can be assumed to fulfill orthologous functions within the sperm tail axonemes of both species. Functional dynein β heavy chain molecules, however, are necessary for the assembly and attachment of outer dynein arms within the sperm tail axoneme. Localization of DhDhc7(Y) to the fertility factor Threads, comprising at least 5.1 Mb of transcriptionally active repetitive DNA, results from an infertile Threads− mutant where large clusters of Threads specifically transcribed satellites and parts of DhDhc7(Y) encoding sequences are missing simultaneously. Consequently, the complete lack of the outer dynein arms in Threads− males most probably causes sperm immotility and hence infertility of the fly. Moreover, preliminary sequence analysis and several other features support the hypothesis that DhDhc7(Y) on the lampbrush loops Threads in D. hydei and Dhc-Yh3 on the lampbrush loops kl-5 in Drosophila melanogaster on the heterochromatic Y chromosome of both species might indeed code for orthologous dynein β heavy chain proteins.

Retrotransposon-like sequences are expressed in Y chromosomal lampbrush loops of Drosophila hydei

1988 ◽  
Vol 203 (3) ◽  
pp. 689-697 ◽  
Author(s):  
Peter Huijser ◽  
Christiane Kirchhoff ◽  
Dirk-Henner Lankenau ◽  
Wolfgang Hennig
Keyword(s):  
Drosophila Hydei ◽  
Lampbrush Loops
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