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Kurek R, Reugels AM, Glätzer KH, Bünemann H. The Y chromosomal fertility factor Threads in Drosophila hydei harbors a functional gene encoding an axonemal dynein beta heavy chain protein. Genetics 1998; 149:1363-76. [PMID: 9649526 PMCID: PMC1460245 DOI: 10.1093/genetics/149.3.1363] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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 beta 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 beta 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 beta heavy chain proteins.
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Affiliation(s)
- R Kurek
- Dipartimento di Genetica e Biologia Molecolare, Universita di Roma 'La Sapienza,' I-00185 Roma, Italia
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2
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Zhimulev IF. Polytene chromosomes, heterochromatin, and position effect variegation. ADVANCES IN GENETICS 1997; 37:1-566. [PMID: 9352629 DOI: 10.1016/s0065-2660(08)60341-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- I F Zhimulev
- Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
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3
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Kurek R, Trapitz P, Bünemann H. Strukturdifferenzierungen in Y-chromosom von Drosophila hydei: the unique morphology of the Y chromosomal lampbrush loops Threads results from 'coaxial shells' formed by different satellite-specific subregions within megabase-sized transcripts. Chromosome Res 1996; 4:87-102. [PMID: 8785614 DOI: 10.1007/bf02259701] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The results of pulsed-field gel electrophoresis (PFGE) analysis and two-colour transcript fluorescence in situ hybridization (FISH) for the three Threads-specific DNA satellites YLII, YLI and rally are in support of long-range clustering of these sequence families within the subterminal region on the long arm of the Y chromosome of Drosophila hydei. On the basis of the linear arrangement of at least four extended clusters of satellite-specific sequences, the loop morphology of wild-type and several mutant Threads can be explained by assumption of a single Threads-specific transcription unit comprising about 5.1 Mb of repetitive DNA located between the Pseudonucleolus and the Nucleolus organizer. Transcription is unidirectional from the Pseudonucleolus towards the terminally located Nucleolus organizer. Transcripts most likely start in front of or within the 3.2 Mb region of YLII-related sequences, pass through subsequent blocks of 1.2 and 0.3 Mb of YLI- and rally-related sequences, respectively, and cease within the region of a smaller block of YLI-related repeats. The megabase-sized transcripts remain physically linked to the DNA axis and their extended satellite-specific regions form coaxial clouds or shells around the central DNA axis. In this way each cluster of earlier-transcribed sequences generates a cloud or shell on top of the later-transcribed ones. According to this model of 'satellite-specific coaxial shells' the tube-like morphology and other peculiarities of the Y chromosomal lampbrush loops Threads can be explained as a result of satellite-specific RNA superstructures and/or formation of extended ribonucleoprotein (RNP) complexes between clusters of satellite-specific transcripts and specific proteins. On the basis of this model the specific morphology of several Threads mutants can be interpreted as the result of large interstitial or terminal deletions that alter the total length of the Threads-specific transcription unit without exerting other major effects on principal features of the transcription process along the Threads.
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Affiliation(s)
- R Kurek
- Institute of Genetics, Heinrich-Heine-Universität Düsseldorf, Germany
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4
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Akhmanova AS, Bindels PC, Xu J, Miedema K, Kremer H, Hennig W. Structure and expression of histone H3.3 genes in Drosophila melanogaster and Drosophila hydei. Genome 1995; 38:586-600. [PMID: 7557364 DOI: 10.1139/g95-075] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
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 (approximately 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.
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Affiliation(s)
- A S Akhmanova
- Department of Molecular and Developmental Genetics, Faculty of Sciences, Catholic University of Nijmegen, The Netherlands
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5
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Varadaraj K, Skinner DM. Cytoplasmic localization of transcripts of a complex G+C-rich crab satellite DNA. Chromosoma 1994; 103:423-31. [PMID: 7859563 DOI: 10.1007/bf00362287] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The primary sequence and higher order structures of a G+C-rich satellite DNA of the Bermuda land crab Gecarcinus lateralis have been described previously. The repeat unit of the satellite is approximately 2.1 kb. In exploring a possible function for this satellite, we asked whether it is transcribed. As a probe for transcripts, we used a segment of DNA amplified from a 368 bp EcoRI fragment from the very highly conserved 3' end of the satellite DNA. During polymerase chain reaction (PCR) amplification, the probe was simultaneously either radiolabeled or biotinylated. Tissue- and stage-specific transcripts were observed when blots of poly(A)+ mRNAs recovered from polysomes isolated from crab tissues [including midgut gland (hepatopancreas), limb bud, and claw muscle] were probed with the satellite DNA fragment. The presence of satellite transcripts in polysomal mRNAs is strong evidence that the transcripts had reached the cytoplasm. To corroborate the presence of transcripts in the cytoplasm, we investigated in situ hybridization of satellite probes with RNAs in tissue sections. Biotinylated satellite DNA probes were applied to sections of midgut gland, limb bud papilla, ovary, or testis of anecdysial crabs. Retention of RNAs in tissue sections was improved by UV-irradiation prior to hybridization. Transcripts were abundant in the cytoplasm of all tissues except testis. Sections of crab midgut gland treated with RNase A prior to hybridization and sections of mouse pancreatic tumor served as controls; neither showed any signals with the probe.
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Affiliation(s)
- K Varadaraj
- Biology Division, Oak Ridge National Laboratory, TN 37831
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6
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Hochstenbach R, Brand R, Hennig W. Transcription of repetitive DNA sequences in the lampbrush loop pair Nooses formed by sterile alleles of fertility gene Q on the Y chromosome of Drosophila hydei. MOLECULAR & GENERAL GENETICS : MGG 1994; 244:653-60. [PMID: 7969035 DOI: 10.1007/bf00282756] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The Y chromosomal lampbrush loop-forming male fertility genes of Drosophila consist mainly of repetitive DNA sequences that do not code for proteins. We investigated whether differences in the transcription of these sequences can be detected in male-sterile alleles of male fertility gene Q, which forms the loop pair Nooses. The loop consists, for approximately two-thirds, of repeats of the Y-specific ay1 family of repetitive DNA sequences. Of the remaining one-third, at least one-half is represented by defective retrotransposons of the gypsy family. Both sequence types are interspersed throughout the loop. Using both ay1 and gypsy sequences as probes for transcript in situ hybridization, we show that, at the level of the light microscope, transcription of neither sequence is detectably affected in the loops formed by a male-sterile allele of gene Q. We conclude that the transcription of ay1 and gypsy is required, but not sufficient for the function of gene Q.
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Affiliation(s)
- R Hochstenbach
- Department of Molecular and Developmental Genetics, Faculty of Sciences, Catholic University of Nijmegen, The Netherlands
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7
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Hochstenbach R, Knops M, Hennig W. Discrimination of related transcribed and non-transcribed repetitive DNA sequences from the Y chromosomes of Drosophila hydei and Drosophila eohydei. MOLECULAR & GENERAL GENETICS : MGG 1994; 243:54-62. [PMID: 8190071 DOI: 10.1007/bf00283876] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The short arm of the Y chromosome of Drosophila hydei carries a single male fertility gene, gene Q, which forms the lampbrush loop pair Nooses. Conflicting observations have been reported concerning the identity of the repetitive DNA sequences that are transcribed in this loop pair. It has been claimed by other investigators that the loop transcripts contain repeats of two distinct, but related families of Y-specific repetitive DNA sequences, ay1 and YsI. We reinvestigated this issue, using as probes single ay1 and YsI repeats which, under stringent conditions, hybridize only to members of their own family. Under non-stringent conditions, both repeats hybridize in situ to Nooses transcripts. However, if hybridization conditions are stringent, only the ay1 probe hybridizes to loop transcripts. Hybridizations to Northern blots of testis RNA confirm these results. Further, YsI repeats are not found the closely related species D. eohydei. We conclude that the YsI repeats are not relevant for the function of fertility gene Q.
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Affiliation(s)
- R Hochstenbach
- Department of Molecular and Developmental Genetics, Faculty of Sciences, Catholic University of Nijmegen, The Netherlands
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8
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Pedersen C, Linde-Laursen I. Chromosomal locations of four minor rDNA loci and a marker microsatellite sequence in barley. Chromosome Res 1994; 2:65-71. [PMID: 8162323 DOI: 10.1007/bf01539456] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Four minor rDNA loci have been mapped physically to barley (Hordeum vulgare L.) chromosomes 1 (7l), 2 (2l), 4 (4l), and 5 (1l) by a two-step in situ hybridization procedure including a GAA microsatellite sequence. Reprobing with the microsatellite resulted in a distinct banding pattern, resembling the C-banding pattern, which enabled unequivocal chromosome identification. This study suggests that gene mapping accuracy may be improved by using probes with well-characterized and narrow hybridization sites as cytological markers which are situated close to the gene locus. One of the rDNA loci is located about 54% out on the short arm of chromosome 4 and it has not previously been reported in barley. We have designated the new locus Nor-l6. rDNA loci on homoeologous group 4 chromosomes have not yet been reported in other Triticeae species. The origin of these 4 minor rDNA loci is discussed in relation to their equilocal distribution on the chromosomes.
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Affiliation(s)
- C Pedersen
- Environmental Science and Technology Department, Risø National Laboratory, Roskilde, Denmark
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9
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Hochstenbach R, Pötgens A, Meijer H, Dijkhof R, Knops M, Schouren K, Hennig W. Partial reconstruction of the lampbrush loop pair Nooses on the Y chromosome of Drosophila hydei. Chromosoma 1993; 102:526-45. [PMID: 8243165 DOI: 10.1007/bf00368346] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We present the analysis of genomic DNA fragments that were isolated as potential segments of the lampbrush loop pair Nooses on the short arm of the Y chromosome of Drosophila hydei. More than 300 kb of DNA were recovered in BamHI lambda and cosmid clone groups. This DNA is composed of the Y-specific ay1 family of repetitive DNA sequences, and of other repetitive DNA sequences, which at least in part are also located elsewhere in the genome (Y-associated sequences). Two additional classes of DNA fragments were obtained from an EcoRI library. One of them consists of ay1 repeats without apparent interspersion, including a total of more than 300 kb of DNA. The other is composed of tandemly repeated YsI sequences, a Y-specific sequence derived from ay1. This class includes more than 400 kb of DNA, which is also not interspersed by other sequences. Our results show that only the ay1 repeats interspersed by Y-associated DNA sequences can represent parts of the 260 kb transcription unit forming the lampbrush loop, whereas the ay1 and YsI repeats without interspersion form separate and nontranscribed clusters of repetitive DNA.
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Affiliation(s)
- R Hochstenbach
- Department of Molecular and Developmental Genetics, Faculty of Sciences, Catholic University of Nijmegen, The Netherlands
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10
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Cytological structure of the native polytene salivary gland nucleus of Drosophila melanogaster: a microsurgical analysis. Chromosoma 1993. [DOI: 10.1007/bf00357099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Hagemann S, Scheer B, Schweizer D. Repetitive sequences in the genome of Anemone blanda: identification of tandem arrays and of dispersed repeats. Chromosoma 1993; 102:312-24. [PMID: 8325163 DOI: 10.1007/bf00661274] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A tandemly repetitive sequence family (AbS1) and a repetitive sequence (Hd) forming part of a larger dispersed element (dorf-1) of Anemone blanda were characterised. The AbS1 satellite sequence family is located in all 4',6-diamidino-2-phenylindole (DAPI) positive intercalary heterochromatic bands and in the DAPI positive heterochromatic terminal region of chromosome 3, while the dispersed Hd homologous sequences are preferentially associated with euchromatic chromosome regions. The major component of the AbS1 satellite is AbS1-H1 with a basic repeat unit of 1640 bp; a minor fraction (AbS1-H5) consists of 320 bp units. A subsection of the AbS1-H1 repeat unit exhibits homologies to the 25S rRNA gene of flowering plants suggesting that the 1.64 kb satellite was generated by amplification of a precursor satellite and/or single copy sequence together with an rDNA fragment. The rDNA homologous region is considered to evolve at a rate similar to pseudogenes and thus the age of this satellite DNA fraction can be roughly estimated as about 27 million years. The dispersed repeated sequence Hd (about 1300 bp) is associated with the 8 kb element dorf-1. A. blanda dorf-1 constitutes about 0.2% of the genome (3 x 10(4) copies), is bounded by identical long terminal repeats, and exhibits partial homology to the Lilium gypsy-type element del1, but has yet to be confirmed as a retrotransposon. In contrast to the AbS1 satellite sequence family, Hd homologous sequences were found not only in A. apennina, the closest relative of A. blanda, but also in A. nemorosa and A. ranunculoides indicating that a progenitor sequence of dorf-1 was present in a common ancestor before speciation occurred.
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Affiliation(s)
- S Hagemann
- Department of Cytology and Genetics, University of Vienna, Austria
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12
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Trapitz P, Bünemann H. Preparation of high molecular weight DNA from Drosophila adults for PFGE analysis. Trends Genet 1992; 8:371-2. [PMID: 1440871 DOI: 10.1016/0168-9525(92)90286-d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- P Trapitz
- Institut für Genetik, Heinrich-Heine-Universität Düsseldorf, FRG
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13
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Trapitz P, Glätzer KH, Bünemann H. Towards a physical map of the fertility genes on the heterochromatic Y chromosome of Drosophila hydei: families of repetitive sequences transcribed on the lampbrush loops Nooses and Threads are organized in extended clusters of several hundred kilobases. MOLECULAR & GENERAL GENETICS : MGG 1992; 235:221-34. [PMID: 1465096 DOI: 10.1007/bf00279364] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The understanding of structure and function of the so-called fertility genes of Drosophila is very limited due to their unusual size--several megabases--and their location on the heterochromatic Y chromosome. Since mapping of these genes has mainly been done by classical cytogenetic analyses using a small number of cytologically visible lampbrush loops as the sole markers for particular fertility genes, the resolution of the genetic map of the Y chromosome is restricted to 3-5 Mb. Here we demonstrate that a substantially finer subdivision of the megabase-sized fertility genes in the subtelomeric regions of the Y chromosome of Drosophila hydei can be achieved by a combination of digestion with restriction enzymes having 6 bp recognition sequences, and pulsed field gel electrophoresis. The physical subdivision is based upon large conserved fragments of repetitive DNA in the size range from 50 up to 1600 kb and refers to the long-range organization of several families of repetitive DNA involved in Y chromosomal transcription processes in primary spermatocytes. We conclude from our results that at least five different families of repetitive DNA specifically transcribed on the lampbrush loops nooses and threads are organized as extended clusters of several hundred kb, essentially free of interspersed non-repetitive sequences.
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Affiliation(s)
- P Trapitz
- Institut für Genetik, Heinrich-Heine-Universität Düsseldorf, FRG
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14
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Cloning and functional expression of Dfurin2, a subtilisin-like proprotein processing enzyme of Drosophila melanogaster with multiple repeats of a cysteine motif. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41914-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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15
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Penrad-Mobayed M, Sourrouille P, Bonnanfant-Jaïs ML, N'Da E, Edström JE, Angelier N. Microdissection and cloning of DNA from landmark loops of amphibian lampbrush chromosomes. Chromosoma 1991; 101:180-8. [PMID: 1790731 DOI: 10.1007/bf00355367] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Microdissection of the "globular" and "granular" landmark loops of Pleurodeles lampbrush chromosomes and subsequent cloning of their DNA yielded several recombinant clones. The 6.6-kb insert of one of them was subcloned and the 600 bp of one subclone was characterized by Southern and slot hybridizations as well as by sequencing. This sequence, designated p130B, was shown to belong to a class of moderately repetitive DNA. RNA expression of this sequence was investigated by in situ hybridization of p130B to the nascent transcripts of lateral loops. Results showed that: (1) the same transcripts were not always found in matrices of landmarks exhibiting the same morphological features; (2) the same transcripts were expressed in loops of different morphological types. Based on these results we suggest that even if there is a morphological similarity of landmark loops, this does not reflect total similarity of their transcripts.
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16
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Hackstein JH, Glätzer KH, Hulsebos TJ. Genetic and cytogenetic analysis of the "Th-Ps" region of the Y chromosome of Drosophila hydei: evidence for dual functions of the lampbrush loop-forming fertility genes? MOLECULAR & GENERAL GENETICS : MGG 1991; 227:293-305. [PMID: 2062310 DOI: 10.1007/bf00259683] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two competing hypotheses have been proposed for the function of the Y chromosomal fertility factors in Drosophila, which form giant lampbrush loops during the primary spermatocyte stage. The first hypothesis suggests a conventional coding function, the second proposes an unconventional gene function mediated through protein binding by nascent transcripts. Therefore, we studied the genetics and cytogenetics of the two Y chromosomal fertility genes A and C of Drosophila hydei (which form the lampbrush loops threads and pseudonucleolus) in order to test the validity of these different hypotheses. Both lampbrush loops bind specific proteins, which are recognized by different antisera. Absence of either of the lampbrush loops does not interfere with the synthesis of the antigens but completely prevents the binding of the particular antigen to other lampbrush loops. Absence of the loops also does not interfere with the postmeiotic presence and localization of the particular antigen. Deletion (or inactivation) of either of the lampbrush loops threads or pseudonucleolus causes sterility of the male flies as do other male-sterile alleles of both fertility genes, which do not affect the morphology of the lampbrush loops. The phenotypic effects of these mutations on sperm morphogenesis are identical for all various male-sterile alleles of each of the fertility genes A and C, regardless of whether a particular allele leaves the loop intact, modifies that loop, or deletes (or inactivates) the loop completely. Finally, the isolation of fertile Y chromosomal mutations which modify the morphology of the lampbrush loops demonstrates that it is possible to uncouple loop morphology and genetic function. These findings do not support the hypothesis that the binding of proteins to a lampbrush loop has a substantial impact on spermiogenesis.
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Affiliation(s)
- J H Hackstein
- Department of Molecular and Developmental Genetics, Catholic University of Nijmegen, Faculty of Science, The Netherlands
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17
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Huijser P, Beckers L, Top B, Hermans M, Sinke R, Hennig W. Poly[d(C-A)].poly[d(G-T)] is highly transcribed in the testes of Drosophila hydei. Chromosoma 1990; 100:48-55. [PMID: 2129287 DOI: 10.1007/bf00337602] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microdissection of the lampbrush loops "threads" and "pseudonucleolus" of Y chromosomes from primary spermatocytes of Drosophila hydei and subsequent microcloning of the DNA yielded several recombinant DNA clones which cross-hybridized in screening the different clone banks. By DNA sequencing we found that the inserts of these cross-hybridizing clones contain blocks of poly[d(C-A].poly[d(G-T)]. Testis RNA contains a large fraction of transcripts with this simple repeated nucleotide sequence. With the aid of transcript in situ hybridization we discovered that the "cones" and "pseudonucleolus" lampbrush loops are the primary sites of transcription of poly[d(C-A)].poly[d(G-T)] in spermatocytes. In addition, we found a strand-specific transcription of (CA/GT)n. In both the "cones" and "pseudonucleolus" the (CA)n strand is transcribed, while in the "pseudonucleolus" (GT)n is also transcribed. Labelled (CA)n probes also react with the protein bodies in spermatid nuclei. These observations are discussed in the context of possible functions of (CA/GT)n transcripts in spermatogenesis.
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Affiliation(s)
- P Huijser
- Department of Molecular and Developmental Genetics, University of Nijmegen, Faculty of Sciences, The Netherlands
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18
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Bonaccorsi S, Gatti M, Pisano C, Lohe A. Transcription of a satellite DNA on two Y chromosome loops of Drosophila melanogaster. Chromosoma 1990; 99:260-6. [PMID: 2119983 DOI: 10.1007/bf01731701] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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. Detailed mapping of satellite DNA sequences along the Y chromosome has recently shown that AA-GAC satellite repeats are a significant component of the kl-5 and ks-1 loop-forming regions. To determine whether these simple repeated sequences are transcribed on the loop structures we performed a series of DNA-RNA in situ hybridization experiments to fixed loop preparations using as a probe cloned AAGAC repeats. These experiments showed that the probe hybridizes with homologous transcripts specifically associated with the kl-5 and ks-1 loops. These transcripts are detected at all stages of development of these two loops, do not appear to migrate to the cytoplasm and are degraded when loops disintegrate during the first meiotic prophase. Moreover, an examination of the testes revealed that the transcription of the AAGAC sequences is restricted to the loops of primary spermatocytes; the other cell types of D. melanogaster spermatogenesis do not exhibit nuclear or cytoplasmic labeling. These experiments were confirmed by RNA blotting analysis which showed that transcription of the AAGAC sequences occurs in wild-type testes but not in X/O testes. The patterns of hybridization to the RNA blots indicated that the transcripts are highly heterogeneous in size, from large (migration at limiting mobility) to less than 1 kb. We discuss the possible function of the AAGAC satellite transcripts, in the light of the available information on the Y chromosome loops of D. melanogaster.
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Affiliation(s)
- S Bonaccorsi
- Centro di Genetica Evoluzionistica del CNR, Roma, Italy
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19
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Lankenau DH, Huijser P, Jansen E, Miedema K, Hennig W. DNA sequence comparison of micropia transposable elements from Drosophila hydei and Drosophila melanogaster. Chromosoma 1990; 99:111-7. [PMID: 2162752 DOI: 10.1007/bf01735326] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Members of the retrotransposon family micropia were discovered as constituents of wild-type Y chromosomal fertility genes from Drosophila hydei. Several members of the micropia family have subsequently been recovered from Drosophila melanogaster and four micropia elements, micropia-DhMiF2, -DhMiF8, -Dm11 and -Dm2, two each from D. hydei and D. melanogaster, have been totally sequenced (17 kb of micropia sequences and 6.8 kb from insertions). Comparative analysis of micropia sequences revealed a complex pattern of divergence within a single Drosophila genome. The divergence includes deletions, possibly by a slipped mispairing mechanism, insertions of a retroposon, and of another retrotransposon (copia) and "positional nucleotide shuffling" within the tandem repeats of the 3' non-protein-coding region of micropia elements. A 10 bp long sequence of each repeat unit of the 3' tandem repeats of micropia elements is highly conserved and is therefore a candidate of functional importance either in transposition events or in regulatory activity on flanking DNA sequences.
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Affiliation(s)
- D H Lankenau
- Department of Molecular and Developmental Genetics, Catholic University, Nijmegen, The Netherlands
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20
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Brand RC, Hennig W. An abundant testis RNA species shows sequence similarity to Y chromosomal and other genomic sites in Drosophila hydei. MOLECULAR & GENERAL GENETICS : MGG 1989; 215:469-77. [PMID: 2468992 DOI: 10.1007/bf00427045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A cDNA clone bank was constructed from testis poly(A)+ RNA of Drosophila hydei and screened for clones which hybridize to Y chromosomal DNA sequences. The insert of clone cDhT14 hybridizes to a family of repeated DNA sequences with members distributed within the Y chromosome and elsewhere in the genome. This type of sequence has earlier been described as the Y-associated class of DNA. Southern blot analysis of DNA from different wild-type strains of D. hydei suggests that members of the T14 family of repeated DNA sequences are parts of a family of transposable elements. The genomic localization of the T14 family of repeated DNA sequences was revealed by in situ hybridization to metaphase and polytene chromosomes, and to transcripts of Y chromosomal lampbrush loops. Approximately 10-15 members (20%-30%) of the T14 sequence family reside in 8.3 kb PstI restriction fragments. A genomic clone of one of these DNA fragments, DhT14-8.3, hybridizes to transcripts on the Y chromosomal lampbrush loop "cones", and in conventional in situ hybridization experiments to region 12D/13A of the X chromosome and to region 112 of chromosome 5. The cDNA clone cDhT14 represents a part of an abundant testis RNA species of 5.0 kb. This RNA is also present in ovaries and in 0-3 h, 3-6 h and 6-12 h embryos, but less abundantly than in testes. Both the Y chromosomal site of the 8.3 kb PstI fragments and sites elsewhere in the genome are actively transcribed. At least one of the latter genomic sites is transcribed into the 5.0 kb RNA species.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R C Brand
- Department of Molecular and Developmental Genetics, Faculty of Sciences, University of Nijmegen, The Netherlands
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Lankenau DH, Huijser P, Jansen E, Miedema K, Hennig W. Micropia: a retrotransposon of Drosophila combining structural features of DNA viruses, retroviruses and non-viral transposable elements. J Mol Biol 1988; 204:233-46. [PMID: 2464689 DOI: 10.1016/0022-2836(88)90572-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The retrotransposon micropia was first described from Y-chromosomal fertility genes of Drosophila hydei. Screening a Drosophila melanogaster genomic library yielded several clones representing micropia elements in D. melanogaster. The DNA sequences of two elements from D. hydei (micropia-DhMiF2 and micropia-DhMiF8) and two elements from D. melanogaster (micropia-Dm2 and micropia-Dm11) permitted a detailed analysis of the spatial organization of micropia constituents. Micropia represents the typical gene organization represented by "core"-protein domains followed by a protease, reverse transcriptase, RNase and integrase domain. New features of the micropia family compared with other retrotransposons are: (1) a region of similarity to class I major histocompatibility complex antigens of mammals; (2) only one main open reading frame of about 4000 bases length; (3) a non-protein-coding region of about 500 base-pairs length between the 3' end of the open reading frame and the 5' start of the 3' long terminal repeat. This region includes 32 base-pair tandem repeats; (4) within the long terminal repeats, 82 base-pair tandem repeats with four potential ecdysteroid receptor binding sites. Because micropia combines many evolutionary features of different viruses, non-viral transposable elements, chromosomal genes and repetitive sequence organizations, this retrotransposon may be seen as a "minigenome" reflecting evolutionary principles of the construction of genomic components.
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Affiliation(s)
- D H Lankenau
- Department of Molecular and Developmental Genetics, Katholieke Universiteit, Nijmegen, The Netherlands
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Huijser P, Kirchhoff C, Lankenau DH, Hennig W. Retrotransposon-like sequences are expressed in Y chromosomal lampbrush loops of Drosophila hydei. J Mol Biol 1988; 203:689-97. [PMID: 2463366 DOI: 10.1016/0022-2836(88)90202-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The DNA sequence family micropia consists of repeated DNA sequences that occur dispersed in the genome of Drosophila hydei. Members of this DNA sequence family were recovered from two recombinant DNA clone banks obtained by microdissection of the two Y chromosomal lampbrush loop threads and pseudonucleolus from primary spermatocyte nuclei. Nucleotide sequence analysis of two of the recombinant DNA clones revealed homology to the DNA region coding for a reverse transcriptase-like protein in retroviruses and retrotransposons. Homologous tissue-specific transcripts of a size of 1.2 x 10(3) base-pairs were found in testes. Transcript in-situ hybridization shows that at least parts of these transcripts are synthesized in these Y chromosomal lampbrush loops, which were originally used for microdissection. Also the cytoplasm of primary spermatocytes contains homologous RNA species. These observations are discussed in the context of lampbrush loop function and evolution.
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Affiliation(s)
- P Huijser
- Department of Molecular and Developmental Genetics, Katholieke Universiteit Nijmegen, The Netherlands
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Trapitz P, Wlaschek M, Bünemann H. Structure and function of Y chromosomal DNA. II. Analysis of lampbrush loop associated transcripts in nuclei of primary spermatocytes of Drosophila hydei by in situ hybridization using asymmetric RNA probes of four different families of repetitive DNA. Chromosoma 1988; 96:159-70. [PMID: 2450723 DOI: 10.1007/bf00331048] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
pSP64/65 subclones of four different families of repetitive sequences on the Y chromosome of Drosophila hydei were used for in vitro synthesis of labelled RNA. Pairs of RNA probes of opposite strand polarity were employed to analyse RNAs transcribed on, or associated with, various Y chromosomal lampbrush loops in nuclei of primary spermatocytes of D. hydei. The results of RNA filter analysis and in situ hybridization experiments can be generalized as follows: (1) Y-specific transcripts are heterogeneous in length and are synthesized on lampbrush loops. (2) Transcription of tandemly repeated sequences is usually strand specific. (3) Members of the same sequence family can be found in transcripts from different lampbrush loops. (4) Transcripts not coded by the Y chromosome are accumulated on different subregions of Y chromosomal lampbrush loops.
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Affiliation(s)
- P Trapitz
- Institut für Genetik der Universität, Düsseldorf, Federal Republic of Germany
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Wlaschek M, Awgulewitsch A, Bünemann H. Structure and function of Y chromosomal DNA. I. Sequence organization and localization of four families of repetitive DNA on the Y chromosome of Drosophila hydei. Chromosoma 1988; 96:145-58. [PMID: 3349874 DOI: 10.1007/bf00331047] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The sequence organization of four different families of Y chromosomal repetitive DNA is characterized at three levels of spatial extension along the Y chromosome of Drosophila hydei. At the lowest level of resolution, DNA blot analysis of Y chromosomal fragments of different lengths and in situ hybridization experiments on metaphase chromosomes demonstrate the clustering of each particular sequence family within one defined region of the chromosome. At a higher level of resolution, family specific repeats can be detected within these clusters by crosshybridization within 10-20 kb long continuous stretches of cloned DNA in EMBL3 phages. At the highest level of resolution, detailed sequence analysis of representative subclones about 1 kb in length reveals a satellite-like head to tail arrangement of family specific degenerated subrepeats as the building scheme common to all four families. Our results provide the first comparative sequence analysis of three novel families of repetitive DNA on the long arm of the Y chromosome of D. hydei. Additional data are presented which support the existence of two related subfamilies of repetitive DNA on the short arm of the Y chromosome.
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Affiliation(s)
- M Wlaschek
- Institut für Genetik der Universität, Düsseldorf, Federal Republic of Germany
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25
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Poly(dC?dA/dG?dT) repeats in the Drosophila genome: a key function for dosage compensation and position effects? Chromosoma 1987. [DOI: 10.1007/bf00330352] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Affiliation(s)
- J H Hackstein
- Department of Genetics, Katholieke Universiteit, Nijmegen, The Netherlands
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Vogt P, Hennig W, ten Hacken D, Verbost P. Evolution of Y chromosomal lampbrush loop DNA sequences of Drosophila. Chromosoma 1986; 94:367-76. [PMID: 2881740 DOI: 10.1007/bf00328637] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The evolutionary conservation of Y chromosomal DNA sequences of Drosophila hydei in different species of the genus Drosophila was studied by in situ hybridization and on genomic DNA blots of restriction enzyme digested DNA. We demonstrated that Y specific DNA sequences, which form major parts of lampbrush loops related to the male fertility genes, are only retained in a few closely related species during evolution. Other Y chromosomal DNA sequences, also present in lampbrush loops but with homology to autosomal and X chromosomal locations, were found in distant species. We propose a model for the evolution of the Y chromosomal lampbrush loops.
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Vogt P, Hennig W. Molecular structure of the lampbrush loops nooses of the Y chromosome of Drosophila hydei. Chromosoma 1986. [DOI: 10.1007/bf00292754] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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