References of "Luciano, Alberto"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailAnalysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes
Franciosi, Federica; Tessario, Irene; Dalbies-Tran, Rozenn et al

in Journal of Visualized Experiments (2017), 123(e55242),

The field of assisted reproduction has been developed to treat infertility in women, companion animals, and endangered species. In the horse, assisted reproduction also allows for the production of ... [more ▼]

The field of assisted reproduction has been developed to treat infertility in women, companion animals, and endangered species. In the horse, assisted reproduction also allows for the production of embryos from high performers without interrupting their sports career and contributes to an increase in the number of foals from mares of high genetic value. The present manuscript describes the procedures used for collecting immature and mature oocytes from horse ovaries using ovum pick-up (OPU). These oocytes were then used to investigate the incidence of aneuploidy by adapting a protocol previously developed in mice. Specifically, the chromosomes and the centromeres of metaphase II (MII) oocytes were fluorescently labeled and counted on sequential focal plans after confocal laser microscope scanning. This analysis revealed a higher incidence in the aneuploidy rate when immature oocytes were collected from the follicles and matured in vitro compared to in vivo. Immunostaining for tubulin and the acetylated form of histone four at specific lysine residues also revealed differences in the morphology of the meiotic spindle and in the global pattern of histone acetylation. Finally, the expression of mRNAs coding for histone deacetylases (HDACs) and acetyl-transferases (HATs) was investigated by reverse transcription and quantitative-PCR (q-PCR). No differences in the relative expression of transcripts were observed between in vitro and in vivo matured oocytes. In agreement with a general silencing of the transcriptional activity during oocyte maturation, the analysis of the total transcript amount can only reveal mRNA stability or degradation. Therefore, these findings indicate that other translational and post-translational regulations might be affected. Overall, the present study describes an experimental approach to morphologically and biochemically characterize the horse oocyte, a cell type that is extremely challenging to study due to low sample availability. However, it can expand our knowledge on the reproductive biology and infertility in monovulatory species. [less ▲]

Detailed reference viewed: 19 (1 ULg)
Full Text
Peer Reviewed
See detailChanges in histone H4 acetylation during in vivo versus in vitro maturation of equine oocytes
Franciosi, Federica; Lodde, Valentina; Goudet, Ghylène et al

in Molecular Human Reproduction (2011)

Epigenetic modifications are established during gametogenesis and preimplantation embryonic development. Any disturbance of the normal natural environment during these critical phases could cause ... [more ▼]

Epigenetic modifications are established during gametogenesis and preimplantation embryonic development. Any disturbance of the normal natural environment during these critical phases could cause alterations of the epigenetic signature. Histone acetylation is an important epigenetic modification involved in the regulation of chromatin organization and gene expression. The present study was aimed to determine whether the proper establishment of post-translational histone H4 acetylation at lysine 8 (AcH4K8), 12 (AcH4K12), and 16 (AcH4K16) of equine oocytes is adversely affected during in vitro maturation when compared to in vivo matured oocytes collected from naturally cycling mares not undergoing ovarian hyperstimulation. The acetylation patterns were investigated by means of indirect immunofluorescence staining with specific antibodies directed against the acetylated lysine residues. Our results indicate that the acetylation state of H4 is dependent on the chromatin configuration in immature GV stage oocytes and it changes in a residue-specific manner along with the increase of chromatin condensation. In particular, the levels of AcH4K8 and AcH4K12 increased significantly, while AcH4K16 decreased significantly from the fibrillar to the condensed state of chromatin configuration within the GV. Moreover, during meiosis K8 and K12 were substantially deacetylated without any differences between in vivo and in vitro conditions, while K16 displayed a strong acetylation in oocytes matured in vivo, and in contrast, it was markedly deacetylated following in vitro maturation. Although the functional meaning of residue-specific acetylation during oocyte differentiation and meiotic resumption needs further investigation, our results support the hypothesis that in vitro maturation conditions can adversely affect oocyte ability to regulate the epigenetic reprogramming, critical for successful meiosis and subsequent embryonic development. [less ▲]

Detailed reference viewed: 31 (3 ULg)