XY chromosome behaviour in the germ-line of the human male: A FISH analysis of spatial orientation, chromatin condensation and pairing

1994 ◽  
Vol 2 (6) ◽  
pp. 445-452 ◽  
Author(s):  
Susan J. Armstrong ◽  
Amanda J. Kirkham ◽  
Maj A. Hult�n
Keyword(s):  
Spatial Orientation ◽  
Germ Line ◽  
Chromatin Condensation ◽  
Fish Analysis ◽  
Chromosome Behaviour ◽  
Human Male

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.

Chromosome condensation induced by geminivirus infection of mature plant cells

2000 ◽  
Vol 113 (7) ◽  
pp. 1149-1160 ◽  
Author(s):  
H.W. Bass ◽  
S. Nagar ◽  
L. Hanley-Bowdoin ◽  
D. Robertson
Keyword(s):  
Coat Protein ◽  
Chromatin Condensation ◽  
Nuclear Periphery ◽  
Nuclear Architecture ◽  
Plant Cells ◽  
Image Data ◽  
Chromosome Condensation ◽  
Fish Analysis ◽  
Viral Dna ◽  
Plant Dna

Tomato golden mosaic virus (TGMV) is a geminivirus that replicates its single-stranded DNA genome through double-stranded DNA intermediates in nuclei of differentiated plant cells using host replication machinery. We analyzed the distribution of viral and plant DNA in nuclei of infected leaves using fluorescence in situ hybridization (FISH). TGMV-infected nuclei showed up to a sixfold increase in total volume and displayed a variety of viral DNA accumulation patterns. The most striking viral DNA patterns were bright, discrete intranuclear compartments, but diffuse nuclear localization was also observed. Quantitative and spatial measurements of high resolution 3-dimensional image data revealed that these compartments accounted for 1–18% of the total nuclear volume or 2–45% of the total nuclear FISH signals. In contrast, plant DNA was concentrated around the nuclear periphery. In a significant number of nuclei, the peripheral chromatin was organized as condensed prophase-like fibers. A combination of FISH analysis and indirect immunofluorescence with viral coat protein antibodies revealed that TGMV virions are associated with the viral DNA compartments. However, the coat protein antibodies failed to cross react with some large viral DNA inclusions, suggesting that encapsidation may occur after significant viral DNA accumulation. Infection by a TGMV mutant with a defective coat protein open reading frame resulted in fewer and smaller viral DNA-containing compartments. Nevertheless, nuclei infected with the mutant virus increased in size and in some cases showed chromosome condensation. Together, these results established that geminivirus infection alters nuclear architecture and can induce plant chromatin condensation characteristic of cells arrested in early mitosis.

scholarly journals Loss of protein phosphatase 1cγ (PPP1CC) leads to impaired spermatogenesis associated with defects in chromatin condensation and acrosome development: an ultrastructural analysis

Reproduction ◽  
2010 ◽  
Vol 139 (6) ◽  
pp. 1021-1029 ◽  
Author(s):  
Nicole Forgione ◽  
A Wayne Vogl ◽  
Susannah Varmuza
Keyword(s):  
Electron Microscopy ◽  
Male Infertility ◽  
Germ Cells ◽  
Chromatin Condensation ◽  
Light And Electron Microscopy ◽  
Testicular Development ◽  
Tissue Architecture ◽  
Genetic Abnormality ◽  
Human Male ◽  
Testicular Failure

Human male infertility affects ∼5% of men, with one-third suffering from testicular failure, likely the result of an underlying genetic abnormality that disrupts spermatogenesis during development. Mouse models of male infertility such as thePpp1ccknockout mouse display very similar phenotypes to humans with testicular failure. MalePpp1ccmutant mice are sterile due to disruptions in spermatogenesis that begin during prepubertal testicular development, and continue into adulthood, often resulting in loss of germ cells to the point of Sertoli cell-only syndrome. The current study employs light and electron microscopy to identify new morphological abnormalities inPpp1ccmutant seminiferous epithelium. This study reveals that germ cells become delayed in their development around stages VII and VIII of spermatogenesis. Loss of these cells likely results in the reduced numbers of elongating spermatids and spermatozoa previously observed in mutant animals. Interestingly,Ppp1ccmutants also display reduced numbers of spermatogonia compared with their wild-type counterparts. Using electron microscopy, we have shown that junction complexes inPpp1ccmutants are ultrastructurally normal, and therefore do not contribute to the breakdown in tissue architecture seen in mutants. Electron microscopy revealed major acrosomal and chromatin condensation defects inPpp1ccmutants. Our observations are discussed in the context of known molecular changes inPpp1ccmutant testes.

scholarly journals L Chromosome Behaviour and Chromosomal Imprinting in Sciara Coprophila

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 440 ◽  
Author(s):  
Prim Singh ◽  
Stepan Belyakin
Keyword(s):  
Related Species ◽  
Constitutive Heterochromatin ◽  
Germ Line ◽  
Chromosome Condensation ◽  
Genetic Constitution ◽  
Chromosome Behaviour ◽  
Stages Of Development ◽  
Closely Related Species ◽  
Supernumerary Chromosomes ◽  
Insight Into

The retention of supernumerary chromosomes in the germ-line of Sciara coprophila is part of a highly-intricate pattern of chromosome behaviours that have fascinated cytogeneticists for over 80 years. Germ-line limited (termed L or “limited”) chromosomes are cytologically heterochromatic and late-replicating, with more recent studies confirming they possess epigenetic hallmarks characteristic of constitutive heterochromatin. Little is known about their genetic constitution although they have been found to undergo cycles of condensation and de-condensation at different stages of development. Unlike most supernumeraries, the L chromosomes in S. coprophila are thought to be indispensable, although in two closely related species Sciara ocellaris and Sciara reynoldsi the L chromosomes, have been lost during evolution. Here, we review what we know about L chromosomes in Sciara coprophila. We end by discussing how study of the L chromosome condensation cycle has provided insight into the site and timing of both the erasure of parental “imprints” and also the placement of a putative “imprint” that might be carried by the sperm into the egg.

scholarly journals Two Isoforms of Drosophila TRF2 Are Involved in Embryonic Development, Premeiotic Chromatin Condensation, and Proper Differentiation of Germ Cells of Both Sexes

2006 ◽  
Vol 26 (20) ◽  
pp. 7492-7505 ◽  
Author(s):  
Daria V. Kopytova ◽  
Aleksey N. Krasnov ◽  
Marina R. Kopantceva ◽  
Elena N. Nabirochkina ◽  
Julia V. Nikolenko ◽  
...  
Keyword(s):  
Germ Cells ◽  
Germ Line ◽  
Chromatin Condensation ◽  
Expression Patterns ◽  
Polytene Chromosomes ◽  
Coiled Coil ◽  
Protein Isoforms ◽  
Related Factor ◽  
Tata Box Binding Protein

ABSTRACT The Drosophila TATA box-binding protein (TBP)-related factor 2 (TRF2 or TLF) was shown to control a subset of genes different from that controlled by TBP. Here, we have investigated the structure and functions of the trf2 gene. We demonstrate that it encodes two protein isoforms: the previously described 75-kDa TRF2 and a newly identified 175-kDa version in which the same sequence is preceded by a long N-terminal domain with coiled-coil motifs. Chromatography of Drosophila embryo extracts revealed that the long TRF2 is part of a multiprotein complex also containing ISWI. Both TRF2 forms are detected at the same sites on polytene chromosomes and have the same expression patterns, suggesting that they fulfill similar functions. A study of the manifestations of the trf2 mutation suggests an essential role of TRF2 during embryonic Drosophila development. The trf2 gene is strongly expressed in germ line cells of adult flies. High levels of TRF2 are found in nuclei of primary spermatocytes and trophocytes with intense transcription. In ovaries, TRF2 is present both in actively transcribing nurse cells and in the transcriptionally inactive oocyte nuclei. Moreover, TRF2 is essential for premeiotic chromatin condensation and proper differentiation of germ cells of both sexes.

scholarly journals Genetic evidence of an unorthodox chromosomal system in the lac insect Kerria lacca (Kerr)

1970 ◽  
Vol 16 (3) ◽  
pp. 341-344 ◽  
Author(s):  
N. S. Chauhan
Keyword(s):  
Germ Line ◽  
Chromosome Behaviour ◽  
Colour Difference ◽  
Male Germ Line ◽  
Cytological Evidence ◽  
Kerria Lacca ◽  
Cytogenetic Evidence ◽  
Lac Insect ◽  
Male Sex ◽  
Sex Cells

SUMMARYThe colour difference (crimson and yellow) in Kerria lacca (Kerr) was used to test the ‘Lecanoid’ system of chromosome behaviour proposed on cytological evidence. The colour strains bred true for colour. Reciprocal matings between the colour strains produced only crimson sons and daughters, confirming that the colour difference is not sex-linked and that the male is somatically a diploid. The phenotypes of the F2 and the backcross generations differed according to the heterozygosity and the direction of cross of the F1 parents, since heterozygous females produced two kinds of gamete but heterozygous males produced only the maternal kind. Thus, while elimination of the paternal gene and hence chromosome was confirmed during the formation of male sex-cells, demonstration of somatic diploidy of the male is not compatible with a ‘Lecanoid’ system in K. lacca. Instead, the available cytogenetic evidence is suggestive of a chromosome system with heterochromatization and elimination of the paternal chromosome-set confined to the male germ line.

scholarly journals Anomalous chromosome behaviour in the germ line of Schistocerca gregaria

Heredity ◽  
1961 ◽  
Vol 16 (2) ◽  
pp. 187-198 ◽  
Author(s):  
B John ◽  
B Naylor
Keyword(s):  
Schistocerca Gregaria ◽  
Germ Line ◽  
Chromosome Behaviour

HUMAN MALE MEIOSIS: CHROMOSOME BEHAVIOUR AT PRE-MEIOTIC AND MEIOTIC STAGES OF SPERMATOGENESIS

1971 ◽  
Vol 13 (3) ◽  
pp. 536-549 ◽  
Author(s):  
Alan McDermott
Keyword(s):  
Metaphase Chromosome ◽  
Meiotic Prophase ◽  
Male Meiosis ◽  
Chromosome Behaviour ◽  
Late Pachytene ◽  
Homologous Chromosomes ◽  
Human Male ◽  
Spermatogonial Metaphase

Normal testicular material was obtained from 53 men. The morphology and behaviour of the chromosomes during pre-meiotic and meiotic stages of spermatogenesis are described in detail. Three types of spermatogonial metaphase chromosome have been identified; they are thought to be from spermatogonia of different generations. Homologous chromosomes appear to be paired at the beginning of spermatogonial prophase, and at the onset of the meiotic prophase (leptotene). Bivalents assume a "lampbrush" appearance during mid- to late pachytene.

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