Association of the extra chromosome of tertiary trisomic male mice with the sex chromosomes during first meiotic prophase, and its significance for impairment of spermatogenesis

Chromosoma ◽  
1979 ◽  
Vol 73 (3) ◽  
pp. 369-379 ◽  
Author(s):  
P. de Boer ◽  
H. E. B. Branje
Keyword(s):  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Extra Chromosome ◽  
Male Mice

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.

Chromosomal synapsis and the meiotic process in male mesquite lizards, Sceloporus grammicus complex

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 398-408 ◽  
Author(s):  
Kent M. Reed ◽  
Jack W. Sites Jr. ◽  
Ira F. Greenbaum
Keyword(s):  
Synaptonemal Complex ◽  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Morphological Characterization ◽  
Autosomal Bivalents ◽  
Meiotic Process ◽  
Low Levels ◽  
Sceloporus Grammicus ◽  
Metaphase I

Meiosis in males of the F5 cytotype of Sceloporus grammicus was examined through the analysis of synaptonemal complexes (SCs), diakinetic (metaphase I) nuclei, and secondary spermatocytes (metaphase II configurations). These data allowed the establishment of criteria for substaging of zygonema and pachynema, morphological characterization of the SC complement, and comparison of the orientation and segregation of the autosomes and sex chromosomes. The analysis of nuclei from all stages of meiotic prophase I (leptonema through diakinesis) provided a useful means of partitioning the temporal sequence of early meiotic events. Three substages of zygonema (Z1–Z3) were established, based on the extent of synapsis of the microchromosomal and macrochromosomal elements. Synaptic initiation of the autosomes and sex chromosomes was synchronous. Two patterns of macrochromosomal synapsis were observed. Whereas synapsis of the biarmed elements was biterminal (i.e., progressing from both ends of the homologs), synapsis of the acrocentric elements was uniterminal involving only the distal (noncentromeric) ends of the homologs. Unique sex-chromosomal characteristics were not observed in S. grammicus and, therefore, the substaging of pachynema was based on subjective criteria. Examination of diakinesis – metaphase I and metaphase II configurations indicated low levels of diakinetic irregularities with balanced segregation of the autosomal bivalents and the sex-chromosomal trivalent.Key words: Sceloporus grammicus, meiosis, synaptonemal complex, substaging.

scholarly journals DNase I nick translation in situ on meiotic chromosomes of the mouse, Mus musculus

1988 ◽  
Vol 90 (4) ◽  
pp. 629-634
Author(s):  
R. Raman ◽  
A.P. Singh ◽  
I. Nanda
Keyword(s):  
Sex Chromosomes ◽  
Mus Musculus ◽  
Meiotic Prophase ◽  
Cell Types ◽  
Dnase I ◽  
Translation Method ◽  
Nick Translation ◽  
Meiotic Chromosomes

DNase-I-sensitive sites have been located on the meiotic chromosomes of the mouse, Mus musculus, by the in situ DNase I nick-translation method. We find that: (1) of all the cell types studied, pachytene nuclei are the most sensitive to DNase I; (2) in diplotene the nicks occur preferentially in the vicinity of chiasmata; (3) the sex chromosomes are also sensitive to the enzyme despite their transcriptional quiescence; and (4) in the sex bivalent the nicks are primarily observed in the putative region of recombination. We conclude that, in addition to discriminating between the transcriptionally active and inactive states of chromatin, DNase I identifies recombination-specific chromatin changes in meiotic prophase.

scholarly journals Chromosome 18 pairing behavior in human trisomic oocytes. Presence of an extra chromosome extends bouquet stage

Reproduction ◽  
2005 ◽  
Vol 129 (5) ◽  
pp. 565-575 ◽  
Author(s):  
I Roig ◽  
P Robles ◽  
R Garcia ◽  
I Martínez-Flores ◽  
Ll Cabero ◽  
...  
Keyword(s):  
Meiotic Prophase ◽  
Extra Chromosome ◽  
Fetal Life ◽  
Chromosome 18 ◽  
Synaptic Process ◽  
Complete Study ◽  
Pairing Behavior ◽  
Bouquet Stage ◽  
Axial Element ◽  
Made In

Little is known about the first meiotic prophase stages in the human female because these occur during fetal life, and only a few studies have addressed aneuploid human oocytes. In this paper, the synaptic process in the meiotic prophase in three 47, XX + 18 cases is analyzed. A complete study of the dynamics of centromeres and telomeres, cohesin core and synapsis development in aneuploid female meiosis was performed. Investigation of chromosome dynamics in prophase of trisomy 18 oocytes show that these events follow the major patterns seen earlier in euploid oocytes. However, there is a significant delay in the resolution of bouquet topology which could relate to the presence of a surplus chromosome 18 axial element in zygotene oocytes. Pachytene oocytes displayed normal synapsis among the three chromosome 18s. However, in some oocytes the surplus chromosome 18 core was aligned to the bivalent 18. As ataxia telangiectasia and Rad3 related kinase (ATR) has been described as a marker for late-pairing chromosomes in mice, ATR distribution was analyzed in human meiocytes –spermatocytes, euploid oocytes and trisomic oocytes. In contrast to the observations made in mice, no preferential staining for late-pairing chromosomes was observed in humans. In the cases studied, bivalent synapses progressed as in a normal ovary, contrasting with the hypothesis that a surplus chromosome can modify pairing of other chromosomes.

scholarly journals NUCLEOLAR AND PERICHROMOSOMAL RNA SYNTHESIS DURING MEIOTIC PROPHASE IN THE MOUSE TESTIS

1974 ◽  
Vol 60 (1) ◽  
pp. 39-53 ◽  
Author(s):  
A. L. Kierszenbaum ◽  
Laura L. Tres
Keyword(s):  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Rna Synthesis ◽  
Transcriptional Activity ◽  
Mouse Testis ◽  
Synthetic Activity ◽  
Synthetic Cell ◽  
Nucleolar Organizers ◽  
Nucleolar Rna ◽  
Silver Grains

The transcriptional activity during meiotic prophase in the mouse testis is studied with light microscopy and high-resolution autoradiographic techniques using [3H]uridine as a labeled precursor. In the present study, two types of RNA synthesis are detected during meiotic prophase: an extranucleolar RNA synthesis of perichromosomal localization and a nucleolar RNA synthetic activity. In some of the autosomes and close to the basal knobs, the activity of the nucleolar organizers is evidenced by the incorporation of [3H]uridine into nucleolar masses from zygotene on and at earlier labeling times. The evolution of nucleoli and the formation of a nucleolus attached to the sex pair are described during the different meiotic stages. Perichromosomal labeling, from leptotene on, reaches a maximum during middle pachytene and falls progressively to a low level at longer incorporation times. Sertoli's cell, the most active RNA synthetic cell in the seminiferous epithelium, rises to a maximum of labeling and drops at earlier times compared with the meiotic prophase cells. The condensed sex chromosomes show some scattered silver grains especially at middle pachytene. The axial chromosome cores and synaptonemal complexes are devoid of silver grains during the meiotic prophase. The observations suggest that a control mechanism operates during meiotic prophase to regulate transcriptional activity in the sex chromosomes and to provide differential RNA synthesis in autosomal bivalents at various stages of prophase and within certain segments of the chromosomes.

scholarly journals The behavior of the X- and Y-chromosomes in the oocyte during meiotic prophase in the B6.YTIR sex-reversed mouse ovary

Reproduction ◽  
2008 ◽  
Vol 135 (2) ◽  
pp. 241-252 ◽  
Author(s):  
Michelle Alton ◽  
Mau Pan Lau ◽  
Michele Villemure ◽  
Teruko Taketo
Keyword(s):  
Y Chromosome ◽  
Germ Cells ◽  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Transcriptional Repression ◽  
Transcriptional Activity ◽  
Sex Chromosome ◽  
Nuclear Antigen ◽  
Mouse Ovary ◽  
Y Chromosomes

Sexual differentiation of the germ cells follows gonadal differentiation, which is determined by the presence or the absence of the Y-chromosome. Consequently, oogenesis and spermatogenesis take place in the germ cells with XX and XY sex chromosomal compositions respectively. It is unclear how sexual dimorphic regulation of meiosis is associated with the sex-chromosomal composition. In the present study, we examined the behavior of the sex chromosomes in the oocytes of the B6.YTIRsex-reversed female mouse, in comparison with XO and XX females. As the sex chromosomes fail to pair in both XY and XO oocytes during meiotic prophase, we anticipated that the pairing failure may lead to excessive oocyte loss. However, the total number of germ cells, identified by immunolabeling of germ cell nuclear antigen 1 (GCNA1), did not differ between XY and XX ovaries or XO and XX ovaries up to the day of delivery. The progression of meiotic prophase, assessed by immunolabeling of synaptonemal complex components, was also similar between the two genotypes of ovaries. These observations suggest that the failure in sex-chromosome pairing is not sufficient to cause oocyte loss. On the other hand, labeling of phosphorylated histone γH2AX, known to be associated with asynapsis and transcriptional repression, was seen over the X-chromosome but not over the Y-chromosome in the majority of XY oocytes at the pachytene stage. For comparison, γH2AX labeling was seen only in the minority of XX oocytes at the same stage. We speculate that the transcriptional activity of sex chromosomes in the XY oocyte may be incompatible with ooplasmic maturation.

scholarly journals Pairing and synapsis in oocytes from female fetuses with euploid and aneuploid chromosome complements

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 899-907 ◽  
Author(s):  
P Robles ◽  
I Roig ◽  
R Garcia ◽  
A Ortega ◽  
J Egozcue ◽  
...  
Keyword(s):  
X Chromosome ◽  
Meiotic Prophase ◽  
High Efficiency ◽  
Extra Chromosome ◽  
Chromosome 21 ◽  
Pachytene Stage ◽  
Meiotic Process ◽  
Human Oocytes ◽  
Meiotic Progression ◽  
Aneuploid Chromosome

Only little is known about the meiotic prophase events in human oocytes, although some of them are involved in the origin of aneuploidies. Here, a broad study of the pairing and synaptic processes in 3263 human euploid and 2613 aneuploid oocytes (47,XX, +21 and 47,XX, +13), using different techniques and methods, is presented in order to elucidate the characteristics of this essential meiotic process. Our results reaffirm the existence of a common high efficiency in the pairing process leading to the obtainment of a bivalent for all chromosomes studied in euploid and aneuploid cases. Nevertheless, this high efficiency was insufficient to consistently produce trivalents in aneuploid oocytes. Trivalent 21 was only observed in 48.8% of the 47,XX, +21 pachytene-stage oocytes studied, and trivalent 13 was found in 68.7% of the 47,XX, +13 pachytene-stage oocytes analyzed. Our data confirm the hypothesis which suggests that in human oocytes the presence of an extra chromosome could interfere in bouquet dynamics. In addition, the pairing process of the X chromosome is altered in trisomic 21 oocytes, providing evidence of the influence that an extra chromosome 21 may cause meiotic progression.

scholarly journals Male mice with large inversions or deletions of X-palindrome arms are fertile and express their associated genes post-meiosis

2018 ◽  
Author(s):  
Alyssa N. Kruger ◽  
Quinn Ellison ◽  
Michele A. Brogley ◽  
Emma R. Gerlinger ◽  
Jacob L. Mueller
Keyword(s):  
Gene Expression ◽  
Sex Chromosomes ◽  
Transcriptional Repression ◽  
Sex Chromosome ◽  
Gene Families ◽  
Single Copy ◽  
Male Mice ◽  
Expression Levels ◽  
Gene Copies ◽  
Palindromic Structure

AbstractLarge (>10 kb) palindromic sequences are enriched on mammalian sex chromosomes. In mice, these palindromes harbor gene families (≥2 gene copies) expressed exclusively in post-meiotic testicular germ cells, at a time when most single-copy sex-linked genes are transcriptionally repressed. This distinct expression pattern led to the hypothesis that containment within palindrome structures or having ≥2 gene enables post-meiotic gene expression. We tested these two hypotheses by using CRISPR to precisely engineer large (10’s of kb) inversions and deletions of X chromosome palindrome arms for two regions carrying the mouse 4930567H17Rik and Mageb5 gene families. We found that 4930567H17Rik and Mageb5 gene expression is unaffected in mice carrying palindrome arm inversions, suggesting that palindromic structure is not important for mediating palindrome-associated gene expression. We also found that 4930567H17Rik and Mageb5 gene expression is reduced by half in mice carrying palindrome arm deletions, allowing us to test whether palindrome-associated genes are sensitive to reduced expression levels resulting in spermatogenic defects. Male mice carrying palindrome arm deletions of 4930567H17Rik or Mageb5, however, are fertile, have normal testis histology, and show no aberrations in spermatogenic cell population frequencies via FACS quantification. Together, these findings suggest that large palindromic structures on the sex chromosomes are not necessary for their associated genes to evade post-meiotic transcriptional repression and that these genes are not sensitive to reduced expression levels. Large sex chromosome palindromes may thus be important for other reasons, such as the long-term evolutionary stability of their associated gene families.

Spermatogenic failure in male mice with four sex chromosomes

Chromosoma ◽  
2001 ◽  
Vol 110 (2) ◽  
pp. 124-129 ◽  
Author(s):  
Tristan A. Rodriguez ◽  
Paul S. Burgoyne
Keyword(s):  
Sex Chromosomes ◽  
Male Mice ◽  
Spermatogenic Failure
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