Limits...
Uncoupled embryonic and extra-embryonic tissues compromise blastocyst development after somatic cell nuclear transfer.

Degrelle SA, Jaffrezic F, Campion E, Lê Cao KA, Le Bourhis D, Richard C, Rodde N, Fleurot R, Everts RE, Lecardonnel J, Heyman Y, Vignon X, Yang X, Tian XC, Lewin HA, Renard JP, Hue I - PLoS ONE (2012)

Bottom Line: SCNT was also associated with a high incidence of discordance in embryonic and extra-embryonic patterns, as evidenced by morphological and molecular "uncoupling".Elongation appeared to be secondarily affected; only 3 of 30 conceptuses had abnormally elongated shapes and there were very few differences in gene expression when they were compared to the controls.When taking into account SCNT conceptus somatic origin, i.e. the reprogramming efficiency of each bovine ear fibroblast (Low: 0029, Med: 7711, High: 5538), we found that embryonic abnormalities or severe embryonic/extra-embryonic uncoupling were more tightly correlated to embryo loss at implantation than were elongation defects.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR 1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France.

ABSTRACT
Somatic cell nuclear transfer (SCNT) is the most efficient cell reprogramming technique available, especially when working with bovine species. Although SCNT blastocysts performed equally well or better than controls in the weeks following embryo transfer at Day 7, elongation and gastrulation defects were observed prior to implantation. To understand the developmental implications of embryonic/extra-embryonic interactions, the morphological and molecular features of elongating and gastrulating tissues were analysed. At Day 18, 30 SCNT conceptuses were compared to 20 controls (AI and IVP: 10 conceptuses each); one-half of the SCNT conceptuses appeared normal while the other half showed signs of atypical elongation and gastrulation. SCNT was also associated with a high incidence of discordance in embryonic and extra-embryonic patterns, as evidenced by morphological and molecular "uncoupling". Elongation appeared to be secondarily affected; only 3 of 30 conceptuses had abnormally elongated shapes and there were very few differences in gene expression when they were compared to the controls. However, some of these differences could be linked to defects in microvilli formation or extracellular matrix composition and could thus impact extra-embryonic functions. In contrast to elongation, gastrulation stages included embryonic defects that likely affected the hypoblast, the epiblast, or the early stages of their differentiation. When taking into account SCNT conceptus somatic origin, i.e. the reprogramming efficiency of each bovine ear fibroblast (Low: 0029, Med: 7711, High: 5538), we found that embryonic abnormalities or severe embryonic/extra-embryonic uncoupling were more tightly correlated to embryo loss at implantation than were elongation defects. Alternatively, extra-embryonic differences between SCNT and control conceptuses at Day 18 were related to molecular plasticity (high efficiency/high plasticity) and subsequent pregnancy loss. Finally, because it alters re-differentiation processes in vivo, SCNT reprogramming highlights temporally and spatially restricted interactions among cells and tissues in a unique way.

Show MeSH

Related in: MedlinePlus

Differential clustering of differentiating tissues and somatic cells.Ranking of SCNTs and controls based on the EE profiles (A) or the E stages (B). Ranking of the fibroblasts (5538, 7711 and 0029) based on their molecular profiles and using the 500 most variant genes among them. The cell passages (p) more temporally proximate to biopsy (p2 to p3) versus nuclear transfer (p7 to 8) were compared. Each ranking series is represented by a dendrogram.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368877&req=5

pone-0038309-g008: Differential clustering of differentiating tissues and somatic cells.Ranking of SCNTs and controls based on the EE profiles (A) or the E stages (B). Ranking of the fibroblasts (5538, 7711 and 0029) based on their molecular profiles and using the 500 most variant genes among them. The cell passages (p) more temporally proximate to biopsy (p2 to p3) versus nuclear transfer (p7 to 8) were compared. Each ranking series is represented by a dendrogram.

Mentions: Despite the similarity in AI, IVP, and SCNT High gastrulation patterns, the latter group nonetheless demonstrated relatively different gene expression in elongating tissues. These differences may reflect quicker cascades of transcriptional regulation or simpler epigenetic architectures that result in SCNT High conceptuses having greater EE plasticity and higher implantation success rates than IVPs (at D21). Given the stronger expression of most DEGs and the weaker expression of EED (which encodes a protein of the Polycomb repressive machinery [64]) in the SCNT High group, higher molecular plasticity is plausible. In contrast, SCNT Med and Low groups differed less from controls in their molecular profiles yet evidenced abnormal embryonic patterns. As a result, when SCNT groups were ranked according to their similarity to controls, a different order was obtained when E versus EE differentiation was used. Furthermore, none of the rankings matched the one obtained using the somatic cells (Fig. 8). As the difference between cell passages was less important for a given cell than the difference between cell donors, our guess is that in vitro culturing differences were of less consequence than cell line characteristics.


Uncoupled embryonic and extra-embryonic tissues compromise blastocyst development after somatic cell nuclear transfer.

Degrelle SA, Jaffrezic F, Campion E, Lê Cao KA, Le Bourhis D, Richard C, Rodde N, Fleurot R, Everts RE, Lecardonnel J, Heyman Y, Vignon X, Yang X, Tian XC, Lewin HA, Renard JP, Hue I - PLoS ONE (2012)

Differential clustering of differentiating tissues and somatic cells.Ranking of SCNTs and controls based on the EE profiles (A) or the E stages (B). Ranking of the fibroblasts (5538, 7711 and 0029) based on their molecular profiles and using the 500 most variant genes among them. The cell passages (p) more temporally proximate to biopsy (p2 to p3) versus nuclear transfer (p7 to 8) were compared. Each ranking series is represented by a dendrogram.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368877&req=5

pone-0038309-g008: Differential clustering of differentiating tissues and somatic cells.Ranking of SCNTs and controls based on the EE profiles (A) or the E stages (B). Ranking of the fibroblasts (5538, 7711 and 0029) based on their molecular profiles and using the 500 most variant genes among them. The cell passages (p) more temporally proximate to biopsy (p2 to p3) versus nuclear transfer (p7 to 8) were compared. Each ranking series is represented by a dendrogram.
Mentions: Despite the similarity in AI, IVP, and SCNT High gastrulation patterns, the latter group nonetheless demonstrated relatively different gene expression in elongating tissues. These differences may reflect quicker cascades of transcriptional regulation or simpler epigenetic architectures that result in SCNT High conceptuses having greater EE plasticity and higher implantation success rates than IVPs (at D21). Given the stronger expression of most DEGs and the weaker expression of EED (which encodes a protein of the Polycomb repressive machinery [64]) in the SCNT High group, higher molecular plasticity is plausible. In contrast, SCNT Med and Low groups differed less from controls in their molecular profiles yet evidenced abnormal embryonic patterns. As a result, when SCNT groups were ranked according to their similarity to controls, a different order was obtained when E versus EE differentiation was used. Furthermore, none of the rankings matched the one obtained using the somatic cells (Fig. 8). As the difference between cell passages was less important for a given cell than the difference between cell donors, our guess is that in vitro culturing differences were of less consequence than cell line characteristics.

Bottom Line: SCNT was also associated with a high incidence of discordance in embryonic and extra-embryonic patterns, as evidenced by morphological and molecular "uncoupling".Elongation appeared to be secondarily affected; only 3 of 30 conceptuses had abnormally elongated shapes and there were very few differences in gene expression when they were compared to the controls.When taking into account SCNT conceptus somatic origin, i.e. the reprogramming efficiency of each bovine ear fibroblast (Low: 0029, Med: 7711, High: 5538), we found that embryonic abnormalities or severe embryonic/extra-embryonic uncoupling were more tightly correlated to embryo loss at implantation than were elongation defects.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR 1198 Biologie du Développement et Reproduction, Jouy-en-Josas, France.

ABSTRACT
Somatic cell nuclear transfer (SCNT) is the most efficient cell reprogramming technique available, especially when working with bovine species. Although SCNT blastocysts performed equally well or better than controls in the weeks following embryo transfer at Day 7, elongation and gastrulation defects were observed prior to implantation. To understand the developmental implications of embryonic/extra-embryonic interactions, the morphological and molecular features of elongating and gastrulating tissues were analysed. At Day 18, 30 SCNT conceptuses were compared to 20 controls (AI and IVP: 10 conceptuses each); one-half of the SCNT conceptuses appeared normal while the other half showed signs of atypical elongation and gastrulation. SCNT was also associated with a high incidence of discordance in embryonic and extra-embryonic patterns, as evidenced by morphological and molecular "uncoupling". Elongation appeared to be secondarily affected; only 3 of 30 conceptuses had abnormally elongated shapes and there were very few differences in gene expression when they were compared to the controls. However, some of these differences could be linked to defects in microvilli formation or extracellular matrix composition and could thus impact extra-embryonic functions. In contrast to elongation, gastrulation stages included embryonic defects that likely affected the hypoblast, the epiblast, or the early stages of their differentiation. When taking into account SCNT conceptus somatic origin, i.e. the reprogramming efficiency of each bovine ear fibroblast (Low: 0029, Med: 7711, High: 5538), we found that embryonic abnormalities or severe embryonic/extra-embryonic uncoupling were more tightly correlated to embryo loss at implantation than were elongation defects. Alternatively, extra-embryonic differences between SCNT and control conceptuses at Day 18 were related to molecular plasticity (high efficiency/high plasticity) and subsequent pregnancy loss. Finally, because it alters re-differentiation processes in vivo, SCNT reprogramming highlights temporally and spatially restricted interactions among cells and tissues in a unique way.

Show MeSH
Related in: MedlinePlus