Morphological and temporal sequence of meiotic prophase development at puberty in the male mouse

1984 ◽  
Vol 65 (1) ◽  
pp. 249-263
Author(s):  
P. Goetz ◽  
A.C. Chandley ◽  
R.M. Speed
Keyword(s):  
Synaptonemal Complex ◽  
Adult Male ◽  
Meiotic Prophase ◽  
Male Mouse ◽  
Late Pachytene ◽  
Diplotene Stage ◽  
Y Chromosomes ◽  
Correct Sequence ◽  
Xy Bivalent ◽  
Morphological Detail

The correct sequence of meiotic prophase development in the male mouse has been established by the use of pubertal males. The first wave of spermatogenesis at this time provides a unique opportunity to study progressive meiotic development in a direct way. Air-dried and micro-spread analyses have been carried out. Temporal and morphological progression at this time is entirely consistent with that occurring in the later waves of meiosis of the adult male. Morphological detail shows delayed pairing of the X and Y chromosomes relative to the autosomes. The longest XY synaptonemal complex is seen in early pachytene cells, occupying up to 72% of the length of the Y and 22% of the length of the X axis. By late pachytene, end-to-end pairing in the XY bivalent is established, the autosomal axes remaining fully paired. Desynapsis of the autosomes commences at early diplotene. A ‘diffuse’ diplotene stage in the male, comparable to the dictyate stage of the female, could not be found. Marked lengthening of the XY and autosomal axes did, however, occur through the diplotene stage.

scholarly journals Analysis of the synaptonemal complex of the nine-banded armadillo, Dasypus novemcinctus

2000 ◽  
Vol 23 (3) ◽  
pp. 613-616 ◽  
Author(s):  
Márcia Denise da Paixão Scavone ◽  
Claudio Oliveira ◽  
Eduardo Bagagli ◽  
Fausto Foresti
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Prophase ◽  
Dasypus Novemcinctus ◽  
Late Pachytene ◽  
Chromosome Synapsis ◽  
Structure Changes ◽  
Y Chromosomes ◽  
Bivalent Chromosome ◽  
In Cells

The synaptonemal complex (SC) of three specimens of the nine-banded armadillo (Dasypus novemcinctus) was analyzed. Thirty-two bivalents (2n = 64) were observed, 31 of them being autosomes and one an XY sexual bivalent. Chromosome synapsis processes and nucleolus structure changes were analyzed in zygotene and pachytene cells, allowing a detailed description of the beginning of meiotic prophase in this species. There was complete synapsis of X and Y chromosomes. Some abnormalities in SC were observed in cells during zygotene and at the beginning of pachytene, but not in cells in the middle and late pachytene, suggesting the occurrence of synaptic adjustments in their SC.

Pattern of X-Y chromosome pairing in the Taiwan vole, Microtus kikuchii

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 27-31 ◽  
Author(s):  
K Mekada ◽  
M Harada ◽  
L K Lin ◽  
K Koyasu ◽  
P M Borodin ◽  
...  
Keyword(s):  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
The Other ◽  
Banding Patterns ◽  
Y Chromosomes

Pairing of X and Y chromosomes at meiotic prophase and the G- and C-banding patterns and nucleolar organizer region (NOR) distribution were analyzed in Microtus kikuchii. M. kikuchii is closely related to M. oeconomus and M. montebelli, karyologically and systematically. The formation of a synaptonemal complex between the X and Y chromosomes at pachytene and end-to-end association at diakinesis – metaphase I are only observed in three species in the genus Microtus; M. kikuchii, M. oeconomus, and M. montebelli. All the other species that have been studied so far have had asynaptic X–Y chromosomes. These data confirm that M. kikuchii, M. oeconomus, and M. montebelli are very closely related, and support the separation of asynaptic and synaptic groups on the phylogenetic tree.Key words: Microtus kikuchii, Microtus phylogeny, karyotype, synaptic sex chromosomes, synaptonemal complex.

Presence of abnormal synaptonemal complexes in heterothallic species of Neurospora

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 697-709 ◽  
Author(s):  
Maja Bojko
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Prophase ◽  
Low Frequency ◽  
Chiasma Formation ◽  
Lateral Component ◽  
Late Pachytene ◽  
Synaptonemal Complexes ◽  
Neurospora Intermedia ◽  
Heterothallic Species ◽  
Type Strains

Synaptonemal complex abnormalities are frequent in reconstructed meiotic prophase nuclei of Neurospora crassa and Neurospora intermedia. Three kinds of synaptonemal complex anomalies were seen: lateral component splits, lateral component junctions, and multiple complexes. The anomalies apparently are formed during or after the pairing process, as they were not seen in the largely unpaired early zygotene chromosomes. Their presence at all the other substages from mid-zygotene to late pachytene indicates that they are not eliminated before the synaptonemal complex decomposes at diplotene. Abnormal synaptonemal complexes were seen in all 19 crosses of N. crassa and N. intermedia that were examined, including matings between standard laboratory strains, inversions, Spore killers, and strains collected from nature. The frequency of affected nuclei and degree of abnormality within a nucleus varied in different matings. No abnormalities were present in the homothallic species Neurospora africana and Neurospora terricola. Structural chromosome aberrations, introgression, and heterozygosity have been eliminated as causes for pairing disorder. The abnormal synaptonemal complexes seemingly do not interfere with normal ascus development and ascospore formation. The affected nuclei are not aborted during meiotic prophase, nor are they eliminated by abortion of mature asci. The abnormal meiocytes do not lead to aneuploidy, as judged by the low frequency of white ascospores in crosses between wild type strains that have many abnormalities. Thus, the abnormal synatonemal complexes do not appear to prevent chiasma formation between homologues.Key words: Neurospora, meiosis, synaptonemal complex.

Sequential meiotic prophase development in the pubertal Indian pygmy field mouse: Synaptic progression of the XY chromosomes, autosomal heterochromatin, and pericentric inversions

Genome ◽  
2000 ◽  
Vol 43 (1) ◽  
pp. 172-180 ◽  
Author(s):  
Amit Bardhan ◽  
T Sharma
Keyword(s):  
Meiotic Prophase ◽  
Pericentric Inversion ◽  
Chiasma Formation ◽  
Subsequent Paper ◽  
Y Chromosomes ◽  
Xy Bivalent ◽  
Mus Terricolor ◽  
Chromosomal Changes ◽  
Meiotic Synapsis ◽  
Chromosomal Mutations

Sequential meiotic prophase development has been followed in the pubertal male pygmy mouse Mus terricolor, with the objective to identify early meiotic prophase stages. The pygmy mouse differs from the common mouse by having large heterochromatic blocks in the X and Y chromosomes. These mice also show various chromosomal mutations; for example, fixed variations of autosomal short arms heterochromatin among different chromosomal species and pericentric inversion polymorphism. Identification of prophase stages was crucial to analyzing effects of heterozygosity for these chromosomal changes on the process of homologous synapsis. Here we describe identification of the prophase stages in M. terricolor, especially the pachytene substages, on the basis of morphology of the XY bivalent. Based on this substaging, we show delayed pairing of the heterochromatic short arms, which may be the reason for their lack of chiasmata. The identification of precise pachytene substages also reveals an early occurrence of "synaptic adjustment" in the pericentric inversion heterobivalents, a mechanism that would prevent chiasma formation in the inverted segment and thereby would abate adverse effects of such heterozygosity. The identification of pachytene substages would serve as the basis to analyze the nature of synaptic anomalies met in M. terricolor hybrids (which will be the basis of a subsequent paper). Key words: Mus terricolor, meiotic synapsis, sex chromosomes, pericentric inversion, heterochromatin.

scholarly journals Loss of Synaptonemal Complex Protein-1, a Synaptonemal Complex Protein, Contributes to the Initiation of Follicular Assembly in the Developing Rat Ovary

Endocrinology ◽  
2005 ◽  
Vol 146 (12) ◽  
pp. 5267-5277 ◽  
Author(s):  
Alfonso Paredes ◽  
Cecilia Garcia-Rudaz ◽  
Bredford Kerr ◽  
Veronica Tapia ◽  
Gregory A. Dissen ◽  
...  
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Prophase ◽  
Primordial Follicles ◽  
Diplotene Stage ◽  
Prophase I ◽  
Meiotic Prophase I ◽  
Complex Protein ◽  
Synaptonemal Complex Protein ◽  
Rat Ovary ◽  
Developing Rat

In the rat ovary, germ and somatic cells become organized into primordial follicles 48–72 h after birth. Although several genes have been implicated in the control of early follicular growth, less is known about the factors involved in the formation of primordial follicles. Using the method of differential display of mRNAs, we found several genes differentially expressed at the time of follicular assembly. One of them encodes synaptonemal complex protein-1 (SCP1), a core component of the protein complex that maintains recombining chromosomes together during prophase I of the first meiotic division in germ cells. This association, evident during the pachytene stage, ends when chromosomal desynapsis begins in the diplotene stage at the end of prophase I. Oocytes become arrested in the diplotene/dictate stage before becoming enclosed into primordial follicles, suggesting that oocytes must complete meiotic prophase I before becoming competent to direct follicle assembly. We now show that attainment of the diplotene stage results in follicular formation. In developing rat ovaries, SCP1 mRNA expression is confined to oocytes and decreases precipitously within 24 h after birth, preceding the organization of primordial follicles. The premature loss of SCP1, achieved via treatment with an antisense oligodeoxynucleotide targeting SCP1 mRNA, resulted in more oocytes reaching the diplotene stage, as evidenced by a decrease in the number of oocytes containing germ cell nuclear antigen-1 (a nuclear protein whose expression ceases in diplotene) and an increase in the number of oocytes expressing MSY2 (a cytoplasmic Y box protein expressed in oocytes that have become arrested in diplotene). SCP1-deficient ovaries exhibited an increased number of newly formed follicles, suggesting that completion of meiotic prophase I endows oocytes with the ability to orchestrate follicular assembly.

Spectral karyotyping (SKY) of mouse meiotic chromosomes

Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 293-298 ◽  
Author(s):  
Henry HQ Heng ◽  
Guo Liu ◽  
Wei Lu ◽  
Steve Bremer ◽  
Christine J Ye ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Synaptonemal Complex ◽  
Meiotic Prophase ◽  
Spectral Karyotyping ◽  
Mitotic Chromosomes ◽  
Meiotic Chromosomes ◽  
Y Chromosomes ◽  
Behavioural Characteristics ◽  
Co Detection

The spectral karyotyping procedure of in situ hybridization with chromosome-specific probes assigns a unique colour code to each of the 21 mouse mitotic chromosomes. We have adapted this procedure to meiotic prophase chromosomes, and the results show that each of the pachytene or metaphase I bivalents can be identified. This technique has the potential to recognize synaptic anomalies and chromosome-specific structural and behavioural characteristics. We confirm these potentials by the recognition of the heterologous synapsis of the X and Y chromosomes and by the variances of synaptonemal complex lengths for each of the colour-coded bivalents in eight prophase nuclei.Key words: SKY, meiosis, synaptonemal complex, multicolour, chromosome painting, spectral karyotyping, protein-SKY co-detection.

scholarly journals Lateral Elements Inside Synaptonemal Complex-Like Polycomplexes in ndt80 Mutants of Yeast Bind DNA

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Hasanuzzaman Bhuiyan ◽  
Gunilla Dahlfors ◽  
Karin Schmekel
Keyword(s):  
In Situ Hybridization ◽  
Electron Microscope ◽  
Synaptonemal Complex ◽  
Immunoelectron Microscopy ◽  
Meiotic Prophase ◽  
Lateral Element ◽  
Homologous Chromosomes ◽  
Meiotic Prophase I ◽  
Dna Antibodies

Abstract The synaptonemal complex (SC) keeps the synapsed homologous chromosomes together during pachytene in meiotic prophase I. Structures that resemble stacks of SCs, polycomplexes, are sometimes found before or after pachytene. We have investigated ndt80 mutants of yeast, which arrest in pachytene. SCs appear normal in spread chromosome preparations, but are only occasionally found in intact nuclei examined in the electron microscope. Instead, large polycomplexes occur in almost every ndt80 mutant nucleus. Immunoelectron microscopy using DNA antibodies show strong preferential labeling to the lateral element parts of the polycomplexes. In situ hybridization using chromosome-specific probes confirms that the chromosomes in ndt80 mutants are paired and attached to the SCs. Our results suggest that polycomplexes can be involved in binding of chromosomes and possibly also in synapsis.

scholarly journals The CSN/COP9 Signalosome Regulates Synaptonemal Complex Assembly during Meiotic Prophase I of Caenorhabditis elegans

PLoS Genetics ◽  
2014 ◽  
Vol 10 (11) ◽  
pp. e1004757 ◽  
Author(s):  
Heather Brockway ◽  
Nathan Balukoff ◽  
Martha Dean ◽  
Benjamin Alleva ◽  
Sarit Smolikove
Keyword(s):  
Caenorhabditis Elegans ◽  
Synaptonemal Complex ◽  
Meiotic Prophase ◽  
Cop9 Signalosome ◽  
Complex Assembly ◽  
Prophase I ◽  
Meiotic Prophase I
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