Glutamine uptake and utilization by preimplantation mouse embryos in CZB medium

Abstract

Summary. At least 71% of CF1 \m=x\ B6SJLF1/J embryos developed from the 1-cell stage to the blastocyst stage in an optimum glutamine concentration of 1 mm, as long as glucose was present after the first 48 h of culture. Blastocysts raised under these conditions had significantly more cells than did blastocysts raised in CZB medium alone (glutamine present, glucose absent). Embryos raised in vivo accumulated 170\p=n-\200 fmol glutamine/embryo/h at the unfertilized egg and 1-cell stages with a decline to 145 fmol/ embryo/h at the 2-cell stage, followed by sharp increases to 400 and 850 fmol/embryo/h at the 8-cell and blastocyst stages. The presence or absence of glucose in the labelling medium had no effect on glutamine uptake by these embryos. Embryos raised in vitro accumulated 2\p=n-\3 times more glutamine at stages comparable to those of embryos raised in vivo. In all cases in which 1-cell to blastocyst development in vitro was successful, glucose was present in the culture medium and the incremental uptake of glutamine between the 8-cell stage and the blastocyst stage was approximately 2-fold. This was also the increment for in-vivo raised embryos. When glucose was not present after the first 48 h, the 8-cell to blastocyst glutamine increment was not significant, and development into blastocysts was reduced. The results also show that glutamine can be used as an energy source for the generation of CO2 through the TCA cycle by all stages of preimplantation mouse development, whether raised in vivo or in vitro from the 1-cell stage. Two-cell embryos raised in vivo converted as much as 70% of the glutamine uptake into CO2, consistent with an important role for glutamine in the very earliest stages of preimplantation development. Cultured blastocysts appeared to convert less glutamine and the presence of glucose in the culture medium seemed to inhibit this conversion.

Renovation of a Drop Embryo Cultures System by Using Refined Mineral oil and the Effect of Glucose and/or Hemoglobin Added to a Serum-free Medium

“…This hypothesis was confirmed by recent finding showing the influence of oil on embryo development during in vitro-culture [12]. In addition, a Chatot, Ziomek and Bavister (CZB) medium [1][2][3][4] was employed as a basic medium of our culture system, but this does not contain several substrates having embryotrophic action reported in previous studies [8][9][10][11].…”

Effects of Glutamine, Glycine and Taurine on the Development of In Vitro Fertilized Bovine Zygotes in a Chemically Defined Medium.

“…The beneficial effect of glutamine on embryonic development has been reported in hamsters [17], mice [4], pigs [22], and cattle [20]. In the present study, however, no beneficial effect of glutamine in combination with essential amino acids for basal medium Eagle (EAA-BME) and nonessential amino acids for minimum essential medium (NEAA-MEM) was observed even in the absence of glucose.…”

A modified culture method significantly improves the development of mouse somatic cell nuclear transfer embryos

“…A synergistic alleviation of two-cell blockage by EDTA and Gln was previously reported for fertilized embryos. EDTA significantly improved preimplantation development of mouse embryos, and Gln was particularly beneficial when provided prior to the four-cell stage (Chatot et al 1989, 1990, NasrEsfahani et al 1992, Lane & Gardner 1997. Our results, however, demonstrate that the absence of EDTA and Gln in culture media prior to the four-cell stage is critically important for the preimplantation development of SCNT embryos, consistent with what Devreker & Hardy (1997) reported regarding the deleterious effect of Gln on mouse preimplantation embryos in vitro.…”

“…Gln has been the subject of consideration for improving culture conditions for preimplantation embryos because it has a complex role in preimplantation development (Summers & Biggers 2003). It was thought to be an energy substrate in place of glucose in early stages to support the embryo's development through a critical period when lactate and pyruvate fail to supply enough energy (Reitzer et al 1979, Chatot et al 1989, 1990, and may enhance the nucleotide pool as an important amino acid that can be used to synthesize purine and pyrimidine nucleotides critical for rapidly division (Salzman et al 1958, Nomura & Rubin 1988). However, Gln was shown to be the principal contributor to the toxic breakdown of amino acids that affect in vitro culturing of preimplantation embryos (Gardner & Lane 1993, Nakazawa et al 1997, Summers & Biggers 2003.…”