scholarly journals Y chromosome loops in Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 120 (4) ◽  
pp. 1015-1034
Author(s):  
S Bonaccorsi ◽  
C Pisano ◽  
F Puoti ◽  
M Gatti
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Primary Spermatocyte ◽  
Maximum Size ◽  
Specific Region ◽  
Meiotic Metaphase ◽  
Fixation Procedure ◽  
Physical Size ◽  
Drosophila Hydei ◽  
Large Clusters

Abstract Primary spermatocyte nuclei of fixed testes of Drosophila melanogaster exhibit three large clusters of thread-like structures, each consisting of two long, continuous, loop-shaped filaments. No comparable intranuclear structures are observed in spermatogonia, secondary spermatocytes or spermatids. The threads begin to form in young spermatocytes, grow throughout spermatocyte development, reach their maximum size in mature spermatocytes and disintegrate prior to meiotic metaphase I. The presence of each cluster of threads depends upon the presence of a specific region of the Y chromosome; when this region is deleted the cluster is absent, and when it is duplicated the cluster is also duplicated. Together these observations strongly suggest that these structures represent giant Y chromosome lampbrush-like loops analogous to those described in Drosophila hydei. Two antibodies, one polyclonal and one monoclonal, differentially react with the three loops of D. melanogaster. Moreover, two of these loops are specifically stained by Giemsa at pH 10. By indirect immunofluorescence with these antibodies followed by Giemsa staining, each loop can be unambiguously identified and its presence and normality readily assessed. This enabled us to perform fine mapping experiments to determine the relationships between the Y chromosome fertility factors and the loops. The loop-forming sites map within the kl-5, kl-3 and ks-1 fertility factors. Regions h3 and h21 of the Y chromosome correspond to the loop-forming sites of kl-5 and ks-1, respectively. Each of these regions contains about 1300 kb of DNA and spans about one-third of its locus. The loop-forming site of the kl-3 locus is coextensive with region h7-h9 which contains about 4300 kb of DNA and corresponds to the minimum physical size of this locus. These data suggest that each loop is an integral part of a different fertility factor, representing the cytological manifestation of its activity in primary spermatocytes. The kl-2, kl-1 and ks-2 fertility regions do not produce any visible intranuclear structure and do not affect the kl-5, kl-3 and ks-1 loops. Thus, these loci may either not form loops at all or produce loop-like structures that we are unable to see because they are physically minute, destroyed by our fixation procedure, or both.

scholarly journals VARIATIONS IN THE NUMBER OF THE Y CHROMOSOMAL rRNA GENES IN DROSOPHILA HYDEI

Genetics ◽  
1976 ◽  
Vol 82 (1) ◽  
pp. 25-34
Author(s):  
W Kunz
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
X Chromosome ◽  
Nucleolus Organizer ◽  
Rrna Genes ◽  
Wild Type ◽  
Drosophila Hydei

ABSTRACT The number of rRNA cistrons is measured by filter saturation hybridization in different stocks of D. hydei, where the wild-type X chromosome has one nucleolus organizer (NO) and the wild-type Y has two separated NO's. (see PDF) females having no X chromosomal NO show an rDNA content exceeding that of a Y chromosome. An even greater increase in the rRNA cistron number is measured in two translocation stocks where the (see PDF) is combined with one half of a Y and, therefore, each stock contains only one of the two Y chromosomal NO's. But when the same Y fragments are brought together with a wild-type X chromosome they lose about one-half of their rRNA cistrons within one generation. Males with two complementary Y fragments but having no X chromosomal NO show a considerably higher rDNA content than the (see PDF) females, although both are equal in respect of their NO number. Consideration is given to related phenomena in Drosophila melanogaster.

scholarly journals The kl-3 loop of the Y chromosome of Drosophila melanogaster binds a tektin-like protein.

Genetics ◽  
1993 ◽  
Vol 133 (3) ◽  
pp. 569-579 ◽  
Author(s):  
C Pisano ◽  
S Bonaccorsi ◽  
M Gatti
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Sodium Dodecyl ◽  
Primary Spermatocyte ◽  
Immunoblot Analysis ◽  
Insoluble Fraction ◽  
Sperm Flagellum ◽  
Binding Function ◽  
Drosophila Testis ◽  
Molecular Masses

Abstract Primary spermatocyte nuclei of Drosophila melanogaster exhibit three giant lampbrush-like loops formed by the kl-5, kl-3 and ks-1 Y-chromosome fertility factors. These structures contain and abundantly transcribe highly repetitive, simple sequence DNAs and accumulate large amounts of non-Y-encoded proteins. By immunizing mice with the 53-kD fraction (enriched in beta 2-tubulin) excised from a sodium dodecyl sulfate-polyacrylamide gel loaded with Drosophila testis proteins we raised a polyclonal antibody, designated as T53-1, which decorates the kl-3 loop and the sperm flagellum. Two dimensional immunoblot analysis showed that the T53-1 antibody reacts with a single protein of about 53 kD, different from the tubulins and present both in X/Y and X/O males. Moreover, the antigen recognized by the T53-1 antibody proved to be testis-specific because it was detected in testes and seminal vesicles but not in other male tissues or in females. The characteristics of the protein recognized by the T53-1 antibody suggested that it might be a member of a class of axonemal proteins, the tektins, known to form Sarkosyl-urea insoluble filaments in the wall of flagellar microtubules. Purification of the Sarkosyl-urea insoluble fraction of D. melanogaster sperm revealed that it contains four polypeptides having molecular masses ranging from 51 to 57 kD. One of these polypeptides reacts strongly with the T53-1 antibody but none of them reacts with antitubulin antibodies. These results indicate that the kl-3 loop binds a non-Y encoded, testis-specific, tektin-like protein which is a constituent of the sperm flagellum. This finding supports the hypothesis that the Y loops fulfill a protein-binding function required for the proper assembly of the axoneme components.

scholarly journals Transcription of gypsy Elements in a Y-Chromosome Male Fertility Gene of Drosqbhila hydei

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 437-446
Author(s):  
Ron Hochstenbach ◽  
Harry Harhangi ◽  
Karin Schouren ◽  
Petra Bindels ◽  
Ron Suijkerbuijk ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Male Fertility ◽  
Fluorescent In Situ Hybridization ◽  
Primary Spermatocyte ◽  
Transcription Unit ◽  
Major Constituent ◽  
Fertility Gene ◽  
Sequence Types ◽  
Gypsy Retrotransposons

Abstract We have found that defective gypsy retrotransposons are a major constituent of the lampbrush loop pair Nooses in the short arm of the Y chromosome of Drosophila hydei. The loop pair is formed by male fertility gene Q during the primary spermatocyte stage of spermatogenesis, each loop being a single transcription unit with an estimated length of 260 kb. Using fluorescent in situ hybridization, we show that throughout the loop transcripts gypsy elements are interspersed with blocks of a tandemly repetitive Y-specific DNA sequence, ay1. Nooses transcripts containing both sequence types show a wide size range on Northern blots, do not migrate to the cytoplasm, and are degraded just before the first meiotic division. Only one strand of ay1 and only the coding strand of gypsy can be detected in the loop transcripts. However, as cloned genomic DNA fragments also display opposite orientations of ay1 and gypsy, such DNA sections cannot be part of the Nooses. Hence, they are most likely derived from the flanking heterochromatin. The direction of transcription of ayl and gypsy thus appears to be of a functional significance.

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

Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 293-308 ◽  
Author(s):  
S R Russell ◽  
K Kaiser
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Germ Line ◽  
Stop Codon ◽  
Chromatin Condensation ◽  
Sperm Chromatin ◽  
Autosomal Gene ◽  
Cdna Clones ◽  
Autosomal Locus ◽  
Functional Protein

Abstract 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.

A marked ring-Y-chromosome in Drosophila hydei with a new type of white variegation

Chromosoma ◽  
1979 ◽  
Vol 71 (1) ◽  
pp. 1-14 ◽  
Author(s):  
H. Beck ◽  
F. M. A. van Breugel ◽  
Ž. Srdić
Keyword(s):  
Y Chromosome ◽  
Drosophila Hydei ◽  
New Type

Microdissection and cloning of DNA from a specific region of Drosophila melanogaster polytene chromosomes

Chromosoma ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 205-216 ◽  
Author(s):  
F. Scalenghe ◽  
E. Turco ◽  
J. E. Edström ◽  
V. Pirrotta ◽  
M. Melli
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosomes ◽  
Specific Region

The endogenous Drosophila melanogaster retrovirus gypsy can propagate in Drosophila hydei cells

2001 ◽  
Vol 264 (5) ◽  
pp. 588-594 ◽  
Author(s):  
B. V. Syomin ◽  
L. I. Fedorova ◽  
S. A. Surkov ◽  
Y. V. Ilyin
Keyword(s):  
Drosophila Melanogaster ◽  
Drosophila Hydei

scholarly journals Association of a protease with polytene chromosomes of Drosophila melanogaster.

1980 ◽  
Vol 87 (2) ◽  
pp. 415-419 ◽  
Author(s):  
J Cavagnaro ◽  
D A Pierce ◽  
J C Lucchesi ◽  
C B Chae
Keyword(s):  
Acetic Acid ◽  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Protease Inhibitors ◽  
Polytene Chromosomes ◽  
Fixation Procedure ◽  
Apparent Effect ◽  
Chloromethyl Ketone ◽  
Diisopropyl Fluorophosphate ◽  
Uniform Labeling

Incubation of Drosophila salivary glands with radioactive diisopropyl fluorophosphate results in the uniform labeling of polytene chromosomes. Extensive labeling is seen only when chromosome squashes are prepared by a formaldehyde fixation procedure and not by standard acetic acid techniques. The labeling is inhibited in the presence of tosylphenylalanine chloromethyl ketone and phenylmethane sulfonylfluoride but not by tosyllysine chloromethyl ketone, suggesting that a chymotrypsin-like serine protease is associated with the chromosomes. Protease inhibitors show no apparent effect on heat-shock specific puffing.

Structure and expression of histone H3.3 genes in Drosophila melanogaster and Drosophila hydei

Genome ◽  
1995 ◽  
Vol 38 (3) ◽  
pp. 586-600 ◽  
Author(s):  
Anna S. Akhmanova ◽  
Petra C. T. Bindels ◽  
Jie Xu ◽  
Koos Miedema ◽  
Hannie Kremer ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sequence Similarity ◽  
Expression Patterns ◽  
Alternative Polyadenylation ◽  
Cdna Clones ◽  
Drosophila Hydei ◽  
Histone H3.3 ◽  
Somatic Tissues ◽  
Polyadenylation Sites ◽  
Limited Sequence

We demonstrate that in Drosophila melanogaster the histone H3.3 replacement variant is encoded by two genes, H3.3A and H3.3B. We have isolated cDNA clones for H3.3A and cDNA and genomic clones for H3.3B. The genes encode exactly the same protein but are widely divergent in their untranslated regions (UTR). Both genes are expressed in embryos and adults; they are expressed in the gonads as well as in somatic tissues of the flies. However, only one of them, H3.3A, shows strong testes expression. The 3′ UTR of the H3.3A gene is relatively short (~250 nucleotides (nt)). H3.3B transcripts can be processed at several polyadenylation sites, the longest with a 3′ UTR of more than 1500 nt. The 3′ processing sites, preferentially used in the gonads and somatic tissues, are different. We have also isolated the Drosophila hydei homologues of the two H3.3 genes. They are quite similar to the D. melanogaster genes in their expression patterns. However, in contrast to their vertebrate counterparts, which are highly conserved in their noncoding regions, the Drosophila genes display only limited sequence similarity in these regions.Key words: H3.3 histone variant, Drosophila, sequence comparison, alternative polyadenylation, testis expression.

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