Abstract
The house mouse is characterised by highly variable chromosome number due to the presence of Robertsonian (Rb) chromosomes. During meiosis in Rb heterozygotes, intricated chromosomal figures are produced, and many unsynapsed regions are present during the first prophase, triggering a meiotic silencing of unsynapsed chromatin (MSUC) in a similar mode to the sex chromosome inactivation. The presence of unsynapsed chromosome regions is associated with impaired spermatogenesis. Interestingly, in male mice carrying multiple Rb trivalents, the frequency of germ cell death, defective tubules, and altered sperm morphology decreases during aging. Here, we studied whether synapsis of trivalent chromosomes and MSUC are involved in this improvement. By immunocytochemistry, we analysed the frequency of unsynapsed chromosomes and of those positive to γH2AX (a marker of MSUC) labelling in spermatocytes of 3-, 5- and 7-month-old Rb heterozygotes. With aging, we observed a decrease of the frequency of unsynapsed chromosomes, of spermatocytes bearing them and of trivalents carrying γH2AX-negative unsynapsed regions. Our quantitative results show that both synapsis and MSUC processes are better accomplished during male aging, partially accounting for the improvement of spermatogenesis.
| Original language | English |
|---|---|
| Pages (from-to) | 269-278 |
| Number of pages | 10 |
| Journal | Chromosome Research |
| Volume | 20 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 2012 |
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Keywords
- Aging
- Asynapsis
- Meiosis
- MSUC
- Robertsonian translocation
- Spermatogenesis
ASJC Scopus subject areas
- Genetics
Cite this
The frequency of heterologous synapsis increases with aging in Robertsonian heterozygous male mice. / Vasco, Chiara; Manterola, Marcia; Page, Jesus; Zuccotti, Maurizio; De La Fuente, Roberto; Redi, Carlo Alberto; Fernandez-Donoso, Raul; Garagna, Silvia.
In: Chromosome Research, Vol. 20, No. 2, 02.2012, p. 269-278.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The frequency of heterologous synapsis increases with aging in Robertsonian heterozygous male mice
AU - Vasco, Chiara
AU - Manterola, Marcia
AU - Page, Jesus
AU - Zuccotti, Maurizio
AU - De La Fuente, Roberto
AU - Redi, Carlo Alberto
AU - Fernandez-Donoso, Raul
AU - Garagna, Silvia
PY - 2012/2
Y1 - 2012/2
N2 - The house mouse is characterised by highly variable chromosome number due to the presence of Robertsonian (Rb) chromosomes. During meiosis in Rb heterozygotes, intricated chromosomal figures are produced, and many unsynapsed regions are present during the first prophase, triggering a meiotic silencing of unsynapsed chromatin (MSUC) in a similar mode to the sex chromosome inactivation. The presence of unsynapsed chromosome regions is associated with impaired spermatogenesis. Interestingly, in male mice carrying multiple Rb trivalents, the frequency of germ cell death, defective tubules, and altered sperm morphology decreases during aging. Here, we studied whether synapsis of trivalent chromosomes and MSUC are involved in this improvement. By immunocytochemistry, we analysed the frequency of unsynapsed chromosomes and of those positive to γH2AX (a marker of MSUC) labelling in spermatocytes of 3-, 5- and 7-month-old Rb heterozygotes. With aging, we observed a decrease of the frequency of unsynapsed chromosomes, of spermatocytes bearing them and of trivalents carrying γH2AX-negative unsynapsed regions. Our quantitative results show that both synapsis and MSUC processes are better accomplished during male aging, partially accounting for the improvement of spermatogenesis.
AB - The house mouse is characterised by highly variable chromosome number due to the presence of Robertsonian (Rb) chromosomes. During meiosis in Rb heterozygotes, intricated chromosomal figures are produced, and many unsynapsed regions are present during the first prophase, triggering a meiotic silencing of unsynapsed chromatin (MSUC) in a similar mode to the sex chromosome inactivation. The presence of unsynapsed chromosome regions is associated with impaired spermatogenesis. Interestingly, in male mice carrying multiple Rb trivalents, the frequency of germ cell death, defective tubules, and altered sperm morphology decreases during aging. Here, we studied whether synapsis of trivalent chromosomes and MSUC are involved in this improvement. By immunocytochemistry, we analysed the frequency of unsynapsed chromosomes and of those positive to γH2AX (a marker of MSUC) labelling in spermatocytes of 3-, 5- and 7-month-old Rb heterozygotes. With aging, we observed a decrease of the frequency of unsynapsed chromosomes, of spermatocytes bearing them and of trivalents carrying γH2AX-negative unsynapsed regions. Our quantitative results show that both synapsis and MSUC processes are better accomplished during male aging, partially accounting for the improvement of spermatogenesis.
KW - Aging
KW - Asynapsis
KW - Meiosis
KW - MSUC
KW - Robertsonian translocation
KW - Spermatogenesis
UR - http://www.scopus.com/inward/record.url?scp=84863603032&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863603032&partnerID=8YFLogxK
U2 - 10.1007/s10577-011-9272-x
DO - 10.1007/s10577-011-9272-x
M3 - Article
C2 - 22231503
AN - SCOPUS:84863603032
VL - 20
SP - 269
EP - 278
JO - Chromosome Research
JF - Chromosome Research
SN - 0967-3849
IS - 2
ER -