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

Molecular and morphological uncoupling of E and EE tissues in SCNT conceptuses.A hierarchical clustering was first performed using the 500 most variant genes from SCNT High, Med, and Low groups. The 30 SCNT conceptuses are presented with their EE and E morphology. Cases of coupled E/EE differentiations were rare. See complementary details in Table 2.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368877&req=5

pone-0038309-g006: Molecular and morphological uncoupling of E and EE tissues in SCNT conceptuses.A hierarchical clustering was first performed using the 500 most variant genes from SCNT High, Med, and Low groups. The 30 SCNT conceptuses are presented with their EE and E morphology. Cases of coupled E/EE differentiations were rare. See complementary details in Table 2.

Mentions: To add to these molecular results, a hierarchical clustering was performed on the 500 most variant genes expressed by SCNT extra-embryonic tissues (n = 30). When the results were analysed in relation to EE morphology and E staging (Fig. 6), discordant patterns were apparent (same numbers, same groups). However, these discordances were not easily linked with two new factors: i) the sex of the conceptus (all SCNTs are females): the absence of a sex effect was confirmed by statistical analyses on AIs (males versus females) as well as on females only (AI-IVP-SCNT; Table S1) and ii) the reprogramming efficiency: SCNT High and Med groups both displayed the lowest number of severe E/EE uncoupling events (3/10) but not the same level of implantation failure (28% and 49%, respectively).


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)

Molecular and morphological uncoupling of E and EE tissues in SCNT conceptuses.A hierarchical clustering was first performed using the 500 most variant genes from SCNT High, Med, and Low groups. The 30 SCNT conceptuses are presented with their EE and E morphology. Cases of coupled E/EE differentiations were rare. See complementary details in Table 2.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0038309-g006: Molecular and morphological uncoupling of E and EE tissues in SCNT conceptuses.A hierarchical clustering was first performed using the 500 most variant genes from SCNT High, Med, and Low groups. The 30 SCNT conceptuses are presented with their EE and E morphology. Cases of coupled E/EE differentiations were rare. See complementary details in Table 2.
Mentions: To add to these molecular results, a hierarchical clustering was performed on the 500 most variant genes expressed by SCNT extra-embryonic tissues (n = 30). When the results were analysed in relation to EE morphology and E staging (Fig. 6), discordant patterns were apparent (same numbers, same groups). However, these discordances were not easily linked with two new factors: i) the sex of the conceptus (all SCNTs are females): the absence of a sex effect was confirmed by statistical analyses on AIs (males versus females) as well as on females only (AI-IVP-SCNT; Table S1) and ii) the reprogramming efficiency: SCNT High and Med groups both displayed the lowest number of severe E/EE uncoupling events (3/10) but not the same level of implantation failure (28% and 49%, respectively).

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