An ?axis-like? material in the centromeric region of metaphase-I chromosomes from mouse spermatocytes

Tandler, C. J.; Solari, Alberto J.

doi:10.1007/bf00123983

Cited by 5 publications

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar T-shaped signals at the inner domain of metaphase I centromeres have been previously described in mouse spermatocytes by immunofluorescence for the chromosomal passenger proteins INCENP and Aurora-B [27], the cohesin subunit radiant sensitive protein 21(RAD21), and the LE proteins SYCP3 and SYCP2 [28]. Likewise, this T-shaped domain has also been detected by electron microscopy by silver staining [35,36] and the Os-PPD cytochemical technique [28]. At first sight, it seems that all these proteins mostly colocalise at the inner domain of metaphase I centromeres.…”

Section: The Mechanisms Underlying the Inner Centromere Domain Assembsupporting

confidence: 76%

A Perikinetochoric Ring Defined by MCAK as a New Centromere Domain in Meiosis

Parra¹,

Gómez²,

Viera³

et al. 2005

PLoS Genet

View full text Add to dashboard Cite

Mitotic Centromere-Associated Kinesin (MCAK) is a member of the kinesin-13 subfamily of kinesin-related proteins. In mitosis, this microtubule-depolymerising kinesin seems to be implicated in chromosome segregation and in the correction of improper kinetochore-microtubule interactions, and its activity is regulated by the Aurora-B kinase. However, there are no published data on its behaviour and function during mammalian meiosis. We have analysed by immunofluorescence in squashed mouse spermatocytes, the distribution and possible function of MCAK, together with Aurora-B, during both meiotic divisions. Our results demonstrate that MCAK and Aurora-B colocalise at the inner domain of metaphase I centromeres. Thus, MCAK shows a ''cone''-like three-dimensional distribution beneath and surrounding the closely associated sister kinetochores. During the second meiotic division, MCAK and Aurora-B also colocalise at the inner centromere domain as a band that joins sister kinetochores, but only during prometaphase II in unattached chromosomes. During chromosome congression to the metaphase II plate, MCAK relocalises and appears as a ring below each sister kinetochore. Aurora-B also relocalises to appear as a ring surrounding and beneath kinetochores but during late metaphase II. Our results demonstrate that the redistribution of MCAK at prometaphase II/metaphase II centromeres depends on tension across the centromere and/or on the interaction of microtubules with kinetochores. We propose that the perikinetochoric rings of MCAK and Aurora-B define a novel transient centromere domain at least in mouse chromosomes during meiosis. We discuss the possible functions of MCAK at the inner centromere domain and at the perikinetochoric ring during both meiotic divisions.

show abstract

Section: The Mechanisms Underlying the Inner Centromere Domain Assembsupporting

confidence: 76%

A Perikinetochoric Ring Defined by MCAK as a New Centromere Domain in Meiosis

Parra¹,

Gómez²,

Viera³

et al. 2005

PLoS Genet

View full text Add to dashboard Cite

show abstract

Presence of a centromeric filament during meiosis

Solari¹,

Tandler²

1991

Genome

View full text Add to dashboard Cite

Spermatocytes at meiotic metaphase I and anaphase I have a characteristic centromeric filament in a variety of vertebrate organisms. This centromeric filament was first demonstrated on mouse spermatocytes and its presence is now extended to spermatocytes from the human, rat, golden hamster, bull, and chicken. The visualization of this filament was possible through the use of a novel silver-staining technique, which allows a high contrast between the filament and the centromeric chromatin. In the species cited, the centromeric filament shares an intense staining, a short (0.2-0.6 micron) length, a curved and branched shape, and location inside the centromeric chromatin of seemingly every homologue of the complement. The similarity of staining reactivity and the observation of transitional structures during first meiotic prophase strongly suggest that the centromeric filament is a remnant of a lateral element of the synaptonemal complex, which stays specifically at both centromeric regions of each bivalent. This filament is not found at the second meiotic division or at the centromeres of mitotic chromosomes. It is assumed that this centromeric filament joins the two sister chromatids of each homologue at the centromere and thus ensures the proper coorientation of sister kinetochores at metaphase I. Further testable assumptions on the functions of this filament are presented.

show abstract

Involvement of the cohesin Rad21 and SCP3 in monopolar attachment of sister kinetochores during mouse meiosis I

Parra

Viera

Gómez

et al. 2004

Journal of Cell Science

152

179

View full text Add to dashboard Cite

SCP3 is a meiosis-specific structural protein appearing at axial elements and lateral elements of the synaptonemal complex. We have analysed the behaviour of SCP3 and the cohesin subunit Rad21 in mouse spermatocytes by means of a squashing technique. Our results demonstrate that both proteins colocalize and are partially released from chromosome arms during late prophase I stages, although they persist at the interchromatid domain of metaphase I bivalents. Thus, Rad21 cannot be considered a `mitotic'-specific variant, but coexists with Rec8. During late prophase I SCP3 and Rad21 accumulate at centromeres, and together with the chromosomal passenger proteins INCENP and aurora-B kinase, show a complex `double cornet'-like distribution at the inner domain of metaphase I centromeres beneath the associated sister kinetochores. We have observed that Rad21 and SCP3 are displaced from centromeres during telophase I when sister kinetochores separate, and are not present at metaphase II centromeres. Thus, we hypothesise that Rad21, and the superimposed SCP3 and SCP2, are involved in the monopolar attachment of sister kinetochores during meiosis I, and are not responsible for the maintenance of sister-chromatid centromere cohesion during meiosis II as previously suggested.

show abstract

An ?axis-like? material in the centromeric region of metaphase-I chromosomes from mouse spermatocytes

Cited by 5 publications

References 35 publications

A Perikinetochoric Ring Defined by MCAK as a New Centromere Domain in Meiosis

A Perikinetochoric Ring Defined by MCAK as a New Centromere Domain in Meiosis

Presence of a centromeric filament during meiosis

Involvement of the cohesin Rad21 and SCP3 in monopolar attachment of sister kinetochores during mouse meiosis I

Contact Info

Product

Resources

About