Limits...
Differential regulation of abundance and deadenylation of maternal transcripts during bovine oocyte maturation in vitro and in vivo.

Thélie A, Papillier P, Pennetier S, Perreau C, Traverso JM, Uzbekova S, Mermillod P, Joly C, Humblot P, Dalbiès-Tran R - BMC Dev. Biol. (2007)

Bottom Line: Throughout in vitro development, oocyte restricted transcripts were progressively degraded until the morula stage, except for MELK ; and the corresponding genes remained silent after major embryonic genome activation.Altogether, our data emphasize the extent of post-transcriptional regulation during oocyte maturation.They do not evidence a general alteration of this phenomenon after in vitro maturation as compared to in vivo maturation, but indicate that some individual messenger RNA can be affected.

View Article: PubMed Central - HTML - PubMed

Affiliation: INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France. Aurore.Thelie@tours.inra.fr

ABSTRACT

Background: In bovine maturing oocytes and cleavage stage embryos, gene expression is mostly controlled at the post-transcriptional level, through degradation and deadenylation/polyadenylation. We have investigated how post transcriptional control of maternal transcripts was affected during in vitro and in vivo maturation, as a model of differential developmental competence.

Results: Using real time PCR, we have analyzed variation of maternal transcripts, in terms of abundance and polyadenylation, during in vitro or in vivo oocyte maturation and in vitro embryo development. Four genes are characterized here for the first time in bovine: ring finger protein 18 (RNF18) and breast cancer anti-estrogen resistance 4 (BCAR4), whose oocyte preferential expression was not previously reported in any species, as well as Maternal embryonic leucine zipper kinase (MELK) and STELLA. We included three known oocyte marker genes (Maternal antigen that embryos require (MATER), Zygote arrest 1 (ZAR1), NACHT, leucine rich repeat and PYD containing 9 (NALP9)). In addition, we selected transcripts previously identified as differentially regulated during maturation, peroxiredoxin 1 and 2 (PRDX1, PRDX2), inhibitor of DNA binding 2 and 3 (ID2, ID3), cyclin B1 (CCNB1), cell division cycle 2 (CDC2), as well as Aurora A (AURKA). Most transcripts underwent a moderate degradation during maturation. But they displayed sharply contrasted deadenylation patterns that account for variations observed previously by DNA array and correlated with the presence of a putative cytoplasmic polyadenylation element in their 3' untranslated region. Similar variations in abundance and polyadenylation status were observed during in vitro maturation or in vivo maturation, except for PRDX1, that appears as a marker of in vivo maturation. Throughout in vitro development, oocyte restricted transcripts were progressively degraded until the morula stage, except for MELK ; and the corresponding genes remained silent after major embryonic genome activation.

Conclusion: Altogether, our data emphasize the extent of post-transcriptional regulation during oocyte maturation. They do not evidence a general alteration of this phenomenon after in vitro maturation as compared to in vivo maturation, but indicate that some individual messenger RNA can be affected.

Show MeSH

Related in: MedlinePlus

Profile of transcripts throughout embryo development. Analysis of transcripts total forms (dark blue) and polyadenylated forms (light blue) during early embryo development: in vitro matured oocyte (MO), in vitro cultured zygote (Z), 2-, 4-, 5/8-cell embryos, morula (M), expanded blastocysts (EB) and hatched blastocysts (HB). The ratio to immature oocytes (set at 1, dotted line) is shown (mean ± SEM). Within the profiles of the total form or polyadenylated form, different superscripts indicate a significant difference (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2211488&req=5

Figure 3: Profile of transcripts throughout embryo development. Analysis of transcripts total forms (dark blue) and polyadenylated forms (light blue) during early embryo development: in vitro matured oocyte (MO), in vitro cultured zygote (Z), 2-, 4-, 5/8-cell embryos, morula (M), expanded blastocysts (EB) and hatched blastocysts (HB). The ratio to immature oocytes (set at 1, dotted line) is shown (mean ± SEM). Within the profiles of the total form or polyadenylated form, different superscripts indicate a significant difference (P < 0.05).

Mentions: Then we analyzed the variation of oocyte markers during the early stages of embryo development (Fig. 3). As examples of housekeeping genes, we quantified 18S and ACTB transcripts. Their levels started to increase between the 5/8-cell and morula stages, as expected since major genome activation occurs in bovine at the 8/16-cell stage, and rose further during blastocyst formation and hatching. By contrast, detection of all oocyte markers decreased between the 5/8-cell and morula stages, and all but MELK decreased further in blastocysts, often below detection level. MELK was indeed activated in blastocysts.


Differential regulation of abundance and deadenylation of maternal transcripts during bovine oocyte maturation in vitro and in vivo.

Thélie A, Papillier P, Pennetier S, Perreau C, Traverso JM, Uzbekova S, Mermillod P, Joly C, Humblot P, Dalbiès-Tran R - BMC Dev. Biol. (2007)

Profile of transcripts throughout embryo development. Analysis of transcripts total forms (dark blue) and polyadenylated forms (light blue) during early embryo development: in vitro matured oocyte (MO), in vitro cultured zygote (Z), 2-, 4-, 5/8-cell embryos, morula (M), expanded blastocysts (EB) and hatched blastocysts (HB). The ratio to immature oocytes (set at 1, dotted line) is shown (mean ± SEM). Within the profiles of the total form or polyadenylated form, different superscripts indicate a significant difference (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2211488&req=5

Figure 3: Profile of transcripts throughout embryo development. Analysis of transcripts total forms (dark blue) and polyadenylated forms (light blue) during early embryo development: in vitro matured oocyte (MO), in vitro cultured zygote (Z), 2-, 4-, 5/8-cell embryos, morula (M), expanded blastocysts (EB) and hatched blastocysts (HB). The ratio to immature oocytes (set at 1, dotted line) is shown (mean ± SEM). Within the profiles of the total form or polyadenylated form, different superscripts indicate a significant difference (P < 0.05).
Mentions: Then we analyzed the variation of oocyte markers during the early stages of embryo development (Fig. 3). As examples of housekeeping genes, we quantified 18S and ACTB transcripts. Their levels started to increase between the 5/8-cell and morula stages, as expected since major genome activation occurs in bovine at the 8/16-cell stage, and rose further during blastocyst formation and hatching. By contrast, detection of all oocyte markers decreased between the 5/8-cell and morula stages, and all but MELK decreased further in blastocysts, often below detection level. MELK was indeed activated in blastocysts.

Bottom Line: Throughout in vitro development, oocyte restricted transcripts were progressively degraded until the morula stage, except for MELK ; and the corresponding genes remained silent after major embryonic genome activation.Altogether, our data emphasize the extent of post-transcriptional regulation during oocyte maturation.They do not evidence a general alteration of this phenomenon after in vitro maturation as compared to in vivo maturation, but indicate that some individual messenger RNA can be affected.

View Article: PubMed Central - HTML - PubMed

Affiliation: INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380 Nouzilly, France. Aurore.Thelie@tours.inra.fr

ABSTRACT

Background: In bovine maturing oocytes and cleavage stage embryos, gene expression is mostly controlled at the post-transcriptional level, through degradation and deadenylation/polyadenylation. We have investigated how post transcriptional control of maternal transcripts was affected during in vitro and in vivo maturation, as a model of differential developmental competence.

Results: Using real time PCR, we have analyzed variation of maternal transcripts, in terms of abundance and polyadenylation, during in vitro or in vivo oocyte maturation and in vitro embryo development. Four genes are characterized here for the first time in bovine: ring finger protein 18 (RNF18) and breast cancer anti-estrogen resistance 4 (BCAR4), whose oocyte preferential expression was not previously reported in any species, as well as Maternal embryonic leucine zipper kinase (MELK) and STELLA. We included three known oocyte marker genes (Maternal antigen that embryos require (MATER), Zygote arrest 1 (ZAR1), NACHT, leucine rich repeat and PYD containing 9 (NALP9)). In addition, we selected transcripts previously identified as differentially regulated during maturation, peroxiredoxin 1 and 2 (PRDX1, PRDX2), inhibitor of DNA binding 2 and 3 (ID2, ID3), cyclin B1 (CCNB1), cell division cycle 2 (CDC2), as well as Aurora A (AURKA). Most transcripts underwent a moderate degradation during maturation. But they displayed sharply contrasted deadenylation patterns that account for variations observed previously by DNA array and correlated with the presence of a putative cytoplasmic polyadenylation element in their 3' untranslated region. Similar variations in abundance and polyadenylation status were observed during in vitro maturation or in vivo maturation, except for PRDX1, that appears as a marker of in vivo maturation. Throughout in vitro development, oocyte restricted transcripts were progressively degraded until the morula stage, except for MELK ; and the corresponding genes remained silent after major embryonic genome activation.

Conclusion: Altogether, our data emphasize the extent of post-transcriptional regulation during oocyte maturation. They do not evidence a general alteration of this phenomenon after in vitro maturation as compared to in vivo maturation, but indicate that some individual messenger RNA can be affected.

Show MeSH
Related in: MedlinePlus