The differential requirement of albumin and sodium citrate on the development of in vitro produced bovine embryos

Abstract

-In vitro culture for bovine embryos is largely not optimal. Our study was to determine the components necessary for early embryo development. In experiment 1, IVF embryos were cultured for two days in CR1aa medium containing sodium citrate and BSA from two sources (Sigma vs. ICPbio), subsequently for additional five days with cumulus monolayer in 10% FBS CR1aa. We found that supplementation with both Sigma-BSA and sodium citrate significantly increased total blastocyst (BL) development compared with the ICPbio-BSA groups (37% vs. 19-21%), and enhanced the total number of high quality (C1 BL, IETS standard) blastocysts (26% vs. 11-17%) (P < 0.05). In experiment 2 with serum free and/or somatic free culture, we found that CR1aa culture can support a comparable embryo development with a supplement of Sigma BSA. The addition of sodium citrate did not increase blastocyst development in either the Sigma-BSA or the ICPbio-BSA groups. An inferior blastocyst development occurring in ICPbio-BSA culture (1-3%) could be rescued by culture in CR1aa supplemented with 10% FBS (29%), more importantly, by culture in CR1aa with a replacement of Sigma BSA (24%) (P < 0.05). C1 blastocysts rescued by FBS and Sigma BSA in ICPbio-BSA culture possessed indistinguishable morphology to embryos developed in a Sigma-BSA, FBS and somatic co-culture system, showing similar cell number/blastocyst (129-180, P > 0.05). Our study found a beneficial effect of sodium citrate and BSA on the in vitro development of bovine IVF embryos during co-culture. We also determined that differential embryotrophic factor(s) contained in BSA and serum, probably not sodium citrate, is necessary for promoting competent morula and blastocyst development in cattle.bovine IVF / BSA / sodium citrate / in vitro culture / embryo development

A prospective randomized sibling-oocyte study of two media systems for culturing cleavage-stage embryos—impact on fertilization rate

“…It is known that citrate does not seem to improve sperm motility after freezing [11]. Addition of citrate to bovine embryo culture appears to enhance morula and blastocyst development, and hatching [12][13][14], although in one study no impact on bovine blastocyst formation was found [15]. The present results indicate that it could be beneficial for early human embryo development to have citrate in the fertilization medium.…”

Efeito do citrato e taurina em meio CR2aa no desenvolvimento de embriões bovinos fecundados in vitro

“…Um efeito benéfico do citrato também pode ser pela presença de células somáticas no cultivo, como realizado no presente trabalho. Sung et al (2004) observaram efeito positivo no desenvolvimento embrionário quando utilizaram citrato durante cocultura, sugerindo que este pode atuar removendo potenciais metabólitos tóxicos secretados por células somáticas. Células do cumulus têm papel antioxidativo no cultivo de oócitos suínos (Tatemoto et al, 2000) e na fertilização em bovinos (Fatehi et al, 2005).…”

“…O uso do citrato no desenvolvimento embrionário tem sido avaliado em meio fluido sintético do oviduto (SOF), estimulando a produção de embriões (Holm et al, 1999), sendo atualmente incorporado à sua composição. O meio SOF suplementado com citrato é amplamente utilizado em ambiente atmosférico com 5% de O 2 (Holm et al, 1999;Sung et al, 2004), contudo, em ambiente com maior concentração de oxigênio (ar atmosférico; 20% de O 2 ) e na ausência de células somáticas, pode resultar em baixo desenvolvimento embrionário (Rizos et al, 2001). O uso do citrato em outras condições de cultivo não tem sido avaliado.…”

Effects of the donor factors and freezing protocols on the bovine embryonic lipid profile

“…Despite the advantages of using BSA and FCS in embryo media, their composition is not stable and varies between batches. They contain vitamins, growth factors, amino acids, energy substrate, and minerals, and they are known to exhibit a variable ability to support blastocyst development in culture [ 63 , 67 ]. The literature does not allow us to conclude whether EG or GLY protocol is more effective since there are no/few pregnancy data available [ 57 ] and the studies comparing the EG and GLY protocols do not show any significant difference [ 68 , 69 ] in survival and hatching rates.…”