Ultrastructure of the Y chromosomal lampbrush loops in primary spermatocytes of Drosophila hydei

Grond, C.; Rutten, R.G.J.; Hennig, Wolfgang

doi:10.1007/bf00292891

Cited by 29 publications

(16 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Independent evidence for the presence of multiple initiation sites in the 'pseudonucleolus' has recently been obtained from immunological studies (Hulsebos et al, 1984). Relationship between transcripts and loop morphology The loop pairs 'threads' and 'pseudonucleolus' have a complex morphology (see Grond et al, 1984). Large portions of the loops contain hardly any nucleic acids but are rich in basic proteins (Kremer, 1983;cf.…”

Section: Discussionmentioning

confidence: 99%

“…Such regions cannot, therefore, be composed of the giant transcripts. Other loop sections contain 35-40 nm ('threads') or 25-30 nm ('pseudonucleolus') particles which are considered as ribonucleoprotein particles (for details, see Grond et al, 1984). Such loop sections should accommodate the transcripts.…”

Section: Discussionmentioning

confidence: 99%

“…Since complementation group C is correlated with the expression of the 'pseudonucleolus' and the other loci do not form prominent loops, the 'pseudonucleolus' is the only large lampbrush chromosome loop in the T(X;Y)74/O males. The character of the 'cones', which are attached to the 'pseudonucleolus', remains uncertain (for discussion, see Hennig, 1967Hennig, , 1984Grond et al, 1984). However, since the 'cones', which are present in both translocations used in our experimeints, are minute compared with the other lampbrush chromosome loops, and since they are expected to display the same type of transcripts in both strains in case they represent a separate transcription unit, they can be neglected in the present experiments.…”

Section: Drosophila Strainsmentioning

confidence: 94%

See 2 more Smart Citations

Lampbrush chromosome loop-specificity of transcript morphology in spermatocyte nuclei of Drosophila hydei

et al. 1984

Self Cite

View full text Add to dashboard Cite

The transcript morphology in the lampbrush chromosome loop pairs ‘threads’ and ‘pseudonucleolus’ of the Y chromosome in primary spermatocytes of Drosophila hydei has been investigated by the Miller spreading technique. Each loop pair carries giant transcripts with a secondary structure characteristic of the respective loop. The lengths of the transcribed regions are in the range 500–1500 kb or even larger. The results of our experiments are discussed in the context of loop ultrastructure, molecular structure and loop function. The high degree of secondary structure may be required to assemble specifically loop‐specific proteins.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Drosophila Strainsmentioning

confidence: 94%

See 1 more Smart Citation

Lampbrush chromosome loop-specificity of transcript morphology in spermatocyte nuclei of Drosophila hydei

et al. 1984

Self Cite

View full text Add to dashboard Cite

show abstract

“…Because of the complicated ultrastructure of the Y chromosomal chromatin seen in ultrathin sections with the electron microscope it seems appropriate to summarize the latest findings about the morphology of these structures so that localization of the antigens may be understood precisely. A more detailed analysis has been carried out previously (10), so that only the main characteristics of the nuclear structures are given. The nooses and the tubular ribbons are characterized by fields of either granules or tubules, whereas the threads are differentiated into a compact fibrillar axis and a surrounding granular matrix.…”

Section: Ultrastructural Data On Y Chromosomal Chromatinmentioning

confidence: 99%

Differential chromosomal distribution of ribonucleoprotein antigens in nuclei of Drosophila spermatocytes.

Glätzer¹,

Kloetzel²

1986

The Journal of Cell Biology

View full text Add to dashboard Cite

Abstract. The ribonucleoprotein (RNP) compositionof the active Y chromosomal structures in spermatocyte nuclei of Drosophila hydei has been investigated using the anti-RNP antibodies Dm 28K2 and pp60 as a probe. Antibody Dm 28K2 was raised against an RNP protein of cytoplasmic RNP particles in D. melanogaster cells, while antibody pp60 was raised against a pre-messenger RNP fraction from oocytes of Xenopus laevis. Both antibodies detect nuclear RNP (nRNP) antigens of D. hydei. This is shown by CsCI density centrifugation of nRNP from D. hydei cells and immunoblotting across the density gradient. Dm 28K2 and pp60 recognize antigens of nRNP complexes which band at a characteristic buoyant density of ~1.4 g/cm 3 in CsC1. By indirect immunofluorescence we observe that the nRNP complexes identified by Dm 28K2 are localized at only two of the five Y chromosomal loop structures which are named according to their distinct morphology. Dm 28K2 decorates RNPs within the "clubs; within the cones, and within the matrix of the "pseudonucleolus" Ultrastructural bodies that are candidates for this immunoreaction are RNP granules that resemble the so-called perichromatin granules. Antibody pp60 recognizes RNP complexes close to the axes of the active Y chromatin. In the "pseudonucleolus" it can be shown that the structures recognized by pp60 are quite distinct from those detected by Dm 28K2. Thus, the "pseudonucleolus" is a striking example for the presence of different RNP populations within a same defined nuclear compartment. Together with previous results (Gliitzer, K. H., 1984, Mol. Gen. Genet., 196:236-243), our data represent evidence that the morphological and apparently functional differences between the active Y chromosomal loops, which are involved in male fertility, are caused by the presence of qualitatively and possibly also functionally different RNP populations within these nuclear compartments. Because both RNP antigens are discussed in the literature in connection with repressed mRNP the observed cross-reaction of the respective antibodies in D. hydei suggests a more general and important function of these proteins in the RNA metabolism of eukaryotic cells.I N eukaryotes the nuclei harbor a heterogeneous mixture of ribonucleoprotein (RNP) 1 complexes. With respect to their specific RNA and protein composition several classes of nuclear RNPs (nRNP) such as heterogeneous nRNP (hnRNP), pre-ribosomal RNP, pre-messenger RNP (pre-mRNP), and small nuclear RNP can be distinguished (reference 3 for review). There is now increasing evidence that the protein constituent of the RNP complexes plays a major role in determining the function of certain RNP particles or strongly influence the metabolic fate of individual transcripts in events such as processing, transport, and storage.With the availability of antibodies directed against nRNP it soon became evident that the distribution of nRNP complexes within the nucleus is not random but in many cases is restricted to specific nuclear sites (e.g., 4, 22, 24). Abbreviations use...

show abstract

“…In terms of its molecular structure the Drosophila Y chromosome remains poorly described. Most studies have focused on the D. hydei lampbrush loop containing fertility factors where it has been shown that the loops represent large single transcription units composed, in part, of loop-specific repetitive sequences (GROND, RUTTEN and HENNIG 1984;DE LOOS et al 1985;HARAVEN, ZUCKERMAN and LIFSCHYTZ 1986;WLASCHEK, AWGULEWITSCH and BUNEMANN 1988). In D. melanogaster more limited studies suggest that approximately 80% of the Y chromosome is composed of simple satellite sequences.…”

mentioning

confidence: 99%

Drosophila melanogaster male germ line-specific transcripts with autosomal and Y-linked genes.

Russell¹,

Kaiser²

1993

Genetics

View full text Add to dashboard Cite

We have identified of set of related transcripts expressed in the germ line of male Drosophila melanogaster. Surprisingly, while one of the corresponding genes is autosomal the remainder are located on the Y chromosome. The autosomal locus, at 77F on chromosome arm 3L, corresponds to the previously described transcription unit 18c, located in the first intron of the gene for an RI subunit of cAMP-dependent protein kinase. The Y chromosome copies have been mapped to region h18-h19 on the cytogenetic map of the Y outside of any of the regions required for male fertility. In contrast to D. melanogaster, where Y-linked copies were found in nine different wild-type strains, no Y-linked copies were found in sibling species. Several apparently Y-derived cDNA clones and one Y-linked genomic clone have been sequenced. The Y-derived genomic DNA shares the same intron/exon structure as the autosomal copy as well as related flanking sequences suggesting that it transposed to the Y from the autosomal locus. However, this particular Y-linked copy cannot encode a functional polypeptide due to a stop codon at amino acid position 72. Divergence among five different cDNA clones ranges from 1.5 to 6% and includes a large number of third position substitutions. We have not yet obtained a full-length cDNA from a Y-linked gene and therefore cannot conclude that the D. melanogaster Y chromosome contains functional protein-coding genes. The autosomal gene encodes a predicted polypeptide with 45% similarity to histones of the H5 class and more limited similarity to cysteine-rich protamines. This protein may be a distant relative of the histone H1 family perhaps involved in sperm chromatin condensation.

show abstract

Ultrastructure of the Y chromosomal lampbrush loops in primary spermatocytes of Drosophila hydei

Cited by 29 publications

References 24 publications

Lampbrush chromosome loop-specificity of transcript morphology in spermatocyte nuclei of Drosophila hydei

Lampbrush chromosome loop-specificity of transcript morphology in spermatocyte nuclei of Drosophila hydei

Differential chromosomal distribution of ribonucleoprotein antigens in nuclei of Drosophila spermatocytes.

Drosophila melanogaster male germ line-specific transcripts with autosomal and Y-linked genes.

Contact Info

Product

Resources

About