Caffeine promotes premature chromosome condensation formation and in vitro development in porcine reconstructed embryos via a high level of maturation promoting factor activity during nuclear transfer

Abstract

When the nucleus in G0/G1 phase is transferred to an enucleated oocyte by nuclear transfer (NT), its nuclear envelope is broken, followed by condensation of chromosome structure by maturation promoting factor (MPF). This morphological remodeling of the transferred interphase nucleus seems to be essential for subsequent development of NT embryos. In this study, we treated porcine NT embryos with caffeine, which has been reported to increase MPF activity, to keep their MPF level high during NT. When 2.5 mM caffeine was added to the handling medium, the proportion of NT embryos showing condensed chromosome increased significantly (P < 0.05). In NT embryos treated with caffeine, the activity of p34 cdc2 kinase was significantly (P < 0.05) higher than in those without caffeine at 3 h post-injection. In addition, the rate of development to the blastocyst stage after activation was significantly (P < 0.05) higher in NT embryos treated with caffeine. These results indicate that caffeine treatment can increase not only the rate of chromosome condensation but also the developmental rate to the blastocyst stage of porcine NT embryos. This action is most likely due to the support/increase of MPF activity throughout the process of NT.Reproduction (

Brilliant Cresyl Blue stain selects largest oocytes with highest mitochondrial activity, maturation-promoting factor activity and embryo developmental competence in prepubertal sheep

“…High MPF activity was observed by Anguita et al (2007) in oocytes with larger diameter and better competence to develop to the blastocyst stage. In addition, MPF activity has also been related to an increase in developmental competence of oocytes treated with caffeine during nuclear transfer (Kawahara et al 2005). In relation to mitochondrial and MPF activities analysed in this work, we could speculate that there is a positive relationship between the ATP produced by the active mitochondria and the ATP production needed to phosphorylate p34 cdc2 and activate the MPF complex.…”

Control of nuclear remodelling and subsequent in vitro development and methylation status of porcine nuclear transfer embryos

“…However, a contrasting suggestion was recently made in cattle, in which a donor nucleus that was exposed to a recipient cytoplasm that had high MPF activity by simultaneous activation for a very short time directly developed a PN and supported a high blastocyst development of NTs (Sung et al 2007). The reason for these differences is unclear, but might be due to differences in the ability of bovine and porcine oocytes to remodel or reprogramme the transferred nucleus (Yin et al 2003, Kawahara et al 2005, Sung et al 2007.…”

“…In the case of porcine NTs, the developmental rate during the preimplantation stage or the total number of cells in the blastocyst stage increases when a donor nucleus is injected into a caffeine-treated recipient (Kawahara et al 2005, Lee & Campbell 2006. The higher total number of cells or developmental capability is thought to occur in PCC because of increased MPF activity in the recipient cytoplasm, rather than the caffeine treatment itself.…”

Acetylation Level of Histone H3 in Early Embryonic Stages Affects Subsequent Development of Miniature Pig Somatic Cell Nuclear Transfer Embryos

“…Dev. 55: [638][639][640][641][642][643][644] 2009) lthough many studies have been performed to improve the developmental competence of miniature pig SCNT embryos [1][2][3][4], the overall efficiency remains low. To obtain sufficient developmental competence for SCNT embryos to develop to term, the differentiated cell nucleus should be subjected to epigenetic reprogramming processes including chromatin remodeling and DNA methylation during preimplantation development.…”