4 research outputs found
Spermatocyte apoptosis, which involves both intrinsic and extrinsic pathways, explains the sterility of Graomys griseoflavus x Graomys centralis male hybrids.
Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hybrids
obtained from crossing Graomys griseoflavus females with Graomys centralis maleswere studied.Testes fromG. centralis,
G. griseoflavus and hybridswere compared at different ages.Terminal transferase-mediated dUTP nick-end labelling assay
(TUNEL), Fas, Bax and cytochrome c labelling were used for apoptosis evaluation, and calbindin D28k staining as an
anti-apoptotic molecule. In 1-month-old animals, spermatocytes were positive for all apoptotic markers, but moderate
TUNEL (+) spermatocyte frequency was only found in G. centralis. At subsequent ages, the apoptotic markers were
downregulated in testes from parental cytotypes, but not in hybrid testes. TUNEL (+) spermatocytes were present at 78%
and 44% per tubule cross-section in 2- and 3-month-old hybrid animals, respectively. Pachytene spermatocyte death in adult
hybrids occurs via apoptosis, as revealed by high caspase-3 expression. Calbindin was highly expressed in spermatocytes
of adult hybrids, in which massive cell death occurs via apoptosis. Calbindin co-localisation with TUNEL or Fas, Bax
and cytochrome c was very limited, suggesting an inverse regulation of calbindin and apoptotic markers. Hybrid sterility
is due to breakdown of spermatogenesis at the pachytene spermatocyte stage. Both extrinsic and intrinsic pathways are
involved in apoptosis of spermatocytes, which are the most sensitive cell type to apoptotic stimuli
Spermatocyte apoptosis, which involves both intrinsic and extrinsic pathways, explains the sterility of Graomys griseoflavus x Graomys centralis male hybrids.
Spermatogenic impairment and the apoptotic pathways involved in establishing sterility of male hybrids
obtained from crossing Graomys griseoflavus females with Graomys centralis maleswere studied.Testes fromG. centralis,
G. griseoflavus and hybridswere compared at different ages.Terminal transferase-mediated dUTP nick-end labelling assay
(TUNEL), Fas, Bax and cytochrome c labelling were used for apoptosis evaluation, and calbindin D28k staining as an
anti-apoptotic molecule. In 1-month-old animals, spermatocytes were positive for all apoptotic markers, but moderate
TUNEL (+) spermatocyte frequency was only found in G. centralis. At subsequent ages, the apoptotic markers were
downregulated in testes from parental cytotypes, but not in hybrid testes. TUNEL (+) spermatocytes were present at 78%
and 44% per tubule cross-section in 2- and 3-month-old hybrid animals, respectively. Pachytene spermatocyte death in adult
hybrids occurs via apoptosis, as revealed by high caspase-3 expression. Calbindin was highly expressed in spermatocytes
of adult hybrids, in which massive cell death occurs via apoptosis. Calbindin co-localisation with TUNEL or Fas, Bax
and cytochrome c was very limited, suggesting an inverse regulation of calbindin and apoptotic markers. Hybrid sterility
is due to breakdown of spermatogenesis at the pachytene spermatocyte stage. Both extrinsic and intrinsic pathways are
involved in apoptosis of spermatocytes, which are the most sensitive cell type to apoptotic stimuli