TY - JOUR
T1 - Complex N-glycans in mgat1 null preimplantation embryos arise from maternal mgat1 RNA
AU - Ioffe, Ella
AU - Liu, Yun
AU - Stanley, Pamela
N1 - Funding Information:
We thank Drs. J. Pollard and Paula Cohen for helpful discussions and for the actin primers. This work was supported by NIH Grant R37 30645 to P.S. and E.I. was supported by Training Grant T32 GM 07491. Partial support was also provided by Core Cancer Grant PO13330.
PY - 1997/10
Y1 - 1997/10
N2 - Mice with a null mutation in the Mgat1 gene lack N-acetylglucosaminyltransferase I (GlcNAc-TI; EC 2.4.1.101), and die at mid-gestation. This result suggested that development of Mgat1(-/-) blastocysts and their implantation could occur in the absence of complex and hybrid N-glycans. However, inner cell mass of all blastocysts from several Mgat1(+/-) heterozygous crosses bind the lectin E-PHA, indicating that Mgat1 null mutant blastocysts are able to synthesize complex N-glycans (Campbell et al., (1995) Glycobiology, 5, 535-543). In order to directly test this hypothesis, Mgat1(-/-) blastocysts were positively identified by polymerase chain reaction (PCR) of genomic DNA. Reverse transcriptase PCR (RT-PCR) of RNA isolated from the same blastocysts, and restriction analysis of the PCR products, revealed that Mgat1 null blastocysts contained Mgat1 RNA derived from the wild-type Mgat1 gene. Consistent with this, all 3.5 day blastocysts from five heterozygous crosses bound the lectin L-PHA, a lectin previously shown not to bind to E8.5 or E9.5 Mgat1(-/-) embryos that lack complex N-glycans (Ioffe and Stanley (1994) Proc. Natl. Acad. Sci., USA, 91, 728-732). Blastocysts of 4.5 days postcoitum (dpc) obtained by culturing 3.5 dpc blastocysts also bound L-PHA. However, mutant embryos that did not bind L-PHA were present among progeny from E5.5 onward. Therefore, the effects of the Mgat1 null mutation are not operative until sometime between implantation and E5.5, due to the continued presence of maternally derived Mgat1 mRNA in preimplantation embryos.
AB - Mice with a null mutation in the Mgat1 gene lack N-acetylglucosaminyltransferase I (GlcNAc-TI; EC 2.4.1.101), and die at mid-gestation. This result suggested that development of Mgat1(-/-) blastocysts and their implantation could occur in the absence of complex and hybrid N-glycans. However, inner cell mass of all blastocysts from several Mgat1(+/-) heterozygous crosses bind the lectin E-PHA, indicating that Mgat1 null mutant blastocysts are able to synthesize complex N-glycans (Campbell et al., (1995) Glycobiology, 5, 535-543). In order to directly test this hypothesis, Mgat1(-/-) blastocysts were positively identified by polymerase chain reaction (PCR) of genomic DNA. Reverse transcriptase PCR (RT-PCR) of RNA isolated from the same blastocysts, and restriction analysis of the PCR products, revealed that Mgat1 null blastocysts contained Mgat1 RNA derived from the wild-type Mgat1 gene. Consistent with this, all 3.5 day blastocysts from five heterozygous crosses bound the lectin L-PHA, a lectin previously shown not to bind to E8.5 or E9.5 Mgat1(-/-) embryos that lack complex N-glycans (Ioffe and Stanley (1994) Proc. Natl. Acad. Sci., USA, 91, 728-732). Blastocysts of 4.5 days postcoitum (dpc) obtained by culturing 3.5 dpc blastocysts also bound L-PHA. However, mutant embryos that did not bind L-PHA were present among progeny from E5.5 onward. Therefore, the effects of the Mgat1 null mutation are not operative until sometime between implantation and E5.5, due to the continued presence of maternally derived Mgat1 mRNA in preimplantation embryos.
KW - Blastocyst
KW - Embryonic development
KW - N-linked glycans
KW - PCR
UR - http://www.scopus.com/inward/record.url?scp=0030668548&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030668548&partnerID=8YFLogxK
U2 - 10.1093/glycob/7.7.913
DO - 10.1093/glycob/7.7.913
M3 - Article
C2 - 9363433
AN - SCOPUS:0030668548
SN - 0959-6658
VL - 7
SP - 913
EP - 919
JO - Glycobiology
JF - Glycobiology
IS - 7
ER -