Search Results
You are looking at 1 - 2 of 2 items for
- Author: Ismael Lamas-Toranzo x
- Refine by access: All content x
Search for other papers by Priscila Ramos-Ibeas in
Google Scholar
PubMed
Search for other papers by Ismael Lamas-Toranzo in
Google Scholar
PubMed
Search for other papers by Álvaro Martínez-Moro in
Google Scholar
PubMed
Search for other papers by Celia de Frutos in
Google Scholar
PubMed
Search for other papers by Alejandra C Quiroga in
Google Scholar
PubMed
Search for other papers by Esther Zurita in
Google Scholar
PubMed
Search for other papers by Pablo Bermejo-Álvarez in
Google Scholar
PubMed
Failures during conceptus elongation are a major cause of pregnancy losses in ungulates, exerting a relevant economic impact on farming. The developmental events occurring during this period are poorly understood, mainly because this process cannot be recapitulated in vitro. Previous studies have established an in vitro post-hatching development (PHD) system that supports bovine embryo development beyond the blastocyst stage, based on agarose gel tunnels and serum- and glucose-enriched medium. Unfortunately, under this system embryonic disc formation is not achieved and embryos show notorious signs of apoptosis and necrosis. The objective of this study has been to develop an in vitro system able to support embryonic disc formation. We first compared post-hatching development inside agarose tunnels or free-floating over an agarose-coated dish in serum- and glucose-enriched medium (PHD medium). Culture inside agarose tunnels shaped embryo morphology by physical constriction, but it restricted embryo growth and did not provide any significant advantage in terms of development of hypoblast and epiblast lineages. In contrast to PHD medium, a chemically defined and enriched medium (N2B27) supported complete hypoblast migration and epiblast survival in vitro, even in the absence of agarose coating. Cells expressing the pluripotency marker SOX2 were observed in ~56% of the embryos and ~25% developed embryonic disc-like structures formed by SOX2+ cells. In summary, here we provide a culture system that supports trophectoderm proliferation, hypoblast migration and epiblast survival after the blastocyst stage.
Search for other papers by Pérez-Gómez Alba in
Google Scholar
PubMed
Search for other papers by Flores-Borobia Inés in
Google Scholar
PubMed
Department of Cell Biology and Histology, Universidad de Murcia. International Excellence Campus for Higher Education and Research (Campus Mare Nostrum), Murcia, Spain
Search for other papers by Hamze Julieta Gabriela in
Google Scholar
PubMed
Search for other papers by Galiano-Cogolludo Beatriz in
Google Scholar
PubMed
Search for other papers by Lamas-Toranzo Ismael in
Google Scholar
PubMed
Search for other papers by González-Brusi Leopoldo in
Google Scholar
PubMed
Search for other papers by Ramos-Ibeas Priscila in
Google Scholar
PubMed
Search for other papers by Bermejo-Álvarez Pablo in
Google Scholar
PubMed
In brief
Bovine embryos lacking SMC2 (a core component of condensins I and II) are unable to survive maternal recognition of pregnancy. SMC2 KO embryos are able to form blastocysts, exhibiting a reduced cell proliferation ability, and arrest their development shortly after hatching.
Abstract
Condensins are large protein complexes required for chromosome assembly and segregation during mitosis and meiosis. Mouse or bovine embryos lacking SMC2 (a core component of condensins I and II) do not complete development to term, but it is unknown when they arrest their development. Herein, we have assessed the developmental ability of bovine embryos lacking SMC2 due to a naturally occurring mutation termed HH3 (Holstein Haplotype 3) or by CRISPR-mediated gene ablation. To determine if embryos homozygous for the HH3 allele survive to maternal recognition of pregnancy, embryonic day (E)14 embryos were flushed from superovulated carrier cows inseminated with a carrier bull. Mendelian inheritance of the HH3 allele was observed at E14 conceptuses but conceptuses homozygous for HH3 failed to achieve elongation and lacked an embryonic disc. To assess the consequence of the ablation of condensins I and II at earlier developmental stages, SMC2 KO bovine embryos were generated in vitro using CRISPR technology. SMC2 KO embryos were able to form blastocysts but exhibited reduced cell proliferation as evidenced by a significantly lower number of total, trophectoderm (CDX2+), and inner cell mass (SOX2+) cells at Day (D) 8 post-fertilization compared to their WT counterparts and were unable to survive to D12 in vitro. SMC2 ablation did not alter relative telomere length at D8, D12, or E14. In conclusion, condensins I and II are required for blastomere mitosis during early development, and embryos lacking those complexes arrest their development shortly after blastocyst hatching.
