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At least 19 recordsLinked to original sources
PubMed2003

A new superfamily of protein-O-fucosyltransferases, alpha2-fucosyltransferases, and alpha6-fucosyltransferases: phylogeny and identification of conserved peptide motifs.

The presence of three conserved peptide motifs shared by alpha2-fucosyltransferases, alpha6-fucosyltransferases, the protein-O-fucosyltransferase family 1 (POFUT1) and a newly identified protein-O-fucosyltransferase family 2 (POFUT2), together with evidence that the present genes encoding for these enzymes have originated from a common ancestor by duplication and divergent evolution, suggests that they constitute a new superfamily of fucosyltransferases.

Amino Acid Motifs↗
PubMed1992

Isolation of a novel human alpha (1,3)fucosyltransferase gene and molecular comparison to the human Lewis blood group alpha (1,3/1,4)fucosyltransferase gene. Syntenic, homologous, nonallelic genes encoding enzymes with distinct acceptor substrate specificities.

Biochemical and genetic evidence indicates that the human genome may encode four or more distinct GDP-fucose:beta-D-N-acetylglucosaminide 3-alpha-L-fucosyltransferase (alpha(1,3)fucosyltransferase) activities. Genes encoding two of these activities have been previously isolated. These correspond to an alpha(1,3/1,4)fucosyltransferase thought to represent the human Lewis blood group locus and an alpha(1,3)fucosyltransferase expressed in the myeloid lineage. We report here the molecular cloning and expression of a third human alpha(1,3)fucosyltransferase gene, homologous to but distinct from the two previously reported human fucosyltransferase genes. When expressed in transfected mammalian cells, this gene determines expression of a fucosyltransferase capable of using N-acetyllactosamine to form the Lewis x epitope, and alpha(2,3)sialyl-N-acetyllactosamine to construct the sialyl Lewis x moiety. This enzyme shares 91% amino acid sequence identity with the human Lewis blood group alpha(1,3/1,4)fucosyltransferase, yet exhibits only trace amounts of alpha(1,4)fucosyltransferase activity. Polymerase chain reaction analyses were used to demonstrate that the gene is syntenic to the Lewis locus on chromosome 19. These analyses also excluded the possibility that this DNA segment represents an allele of the Lewis locus that encodes alpha(1,3)fucosyltransferase but not alpha(1,4)fucosyltransferase activity. These results are consistent with the hypothesis that this gene encodes the human "plasma type" alpha(1,3)fucosyltransferase, and suggest a molecular basis for a family of human alpha(1,3)fucosyltransferase genes.

Alleles↗
PubMed1989

Characterization of fucosyltransferase activity during mouse spermatogenesis: evidence for a cell surface fucosyltransferase.

Fucosyltransferase activity was quantified in mouse germ cells at different stages of spermatogenesis. Specifically, fucosyltransferase activities of pachytene spermatocytes, round spermatids, and cauda epididymal sperm were compared. Fucosyltransferase activity of mixed germ cells displayed an apparent Vmax of 17 pmol (mg of protein)-1 min-1 and an apparent Km of approximately 13 microM for GDP-L-[14C]fucose in the presence of saturating amounts of asialofetuin at 33 degrees C. Under these conditions, cellular fucosyltransferase activity was found to increase during spermatogenesis. In agreement with assays of intact cells, examination of subcellular fractions indicated that a large fraction of fucosyltransferase activity was associated with the cell surface. The fraction of fucosyltransferase activity that was associated with the cell surface progressively increased throughout spermatogenesis and epididymal maturation so that nearly all of the fucosyltransferase in epididymal sperm was on the cell surface. Specifically, by comparison of activities in the presence and absence of the detergent NP-40, the fraction of fucosyltransferase activity that was associated with the cell surface in pachytene spermatocytes, round spermatids, and epididymal sperm was 0.36, 0.5, and 0.85, respectively. These results suggest that a cell surface fucosyltransferase may be important during differentiation of spermatogenic cells in the testis as well as during epididymal maturation and fertilization.

Animals↗
PubMed1999

Expression of human alpha-l-fucosyltransferase gene homologs in monkey kidney COS cells and modification of potential fucosyltransferase acceptor substrates by an endogenous glycosidase.

Previous investigations on the monkey kidney COS cell line demonstrated the weak expression of fucosylated cell surface antigens and presence of endogenous fucosyltransferase activities in cell extracts. RT-PCR analyses have now revealed expression of five homologs of human fucosyltransferase genes, FUT1, FUT4, FUT5, FUT7, and FUT8, in COS cell mRNA. The enzyme in COS cell extracts acting on unsialylated Type 2 structures is closely similar in its properties to the alpha1,3-fucosyltransferase encoded by human FUT4 gene and does not resemble the product of the FUT5 gene. Although FUT1 is expressed in the COS cell mRNA, it has not been possible to demonstrate alpha1,2-fucosyltransferase activity in cell extracts but the presence of Le(y) and blood-group A antigenic determinants on the cell surface imply the formation of H-precursor structures at some stage. The most strongly expressed fucosyltransferase in the COS cells is the alpha1,6-enzyme transferring fucose to the innermost N -acetylglucosamine unit in N -glycan chains; this enzyme is similar in its properties to the product of the human FUT8 gene. The enzymes resembling the human FUT4 and FUT8 gene products both had pH optima of 7.0 and were resistant to 10 mM NEM. The incorporation of fucose into asialo-fetuin was optimal at 5.5 and was inhibited by 10 mM NEM. This result initially suggested the presence of a third fucosyltransferase expressed in the COS cells but we have now shown that triantennary N- glycans with terminal nonreducing galactose units, similar to those present in asialo-fetuin, are modified by a weak endogenous beta-galactosidase in the COS cell extracts and thereby rendered suitable substrates for the alpha1,6-fucosyltransferase.

ABO Blood-Group System↗
PubMed1981

Glycosyltransferases of the human cervical epithelium. I. Characterization of a beta-galactoside alpha-2-L-fucosyltransferase and the identification of a beta-N-acetylglucosaminide alpha-3-L-fucosyltransferase.

Using phenyl beta-D-galactoside as an acceptor, alpha-2-L-fucosyltransferase activity was identified in human cervical epithelium with pH optima at 6.0 and 7.2. The different response to p-chloromercuribenzoate, and ability to utilise asialofetuin as an acceptor, suggests the presence of two fucosyltransferases. The acid form is probably involved in glycoprotein synthesis in vivo. At pH 6.0, fucosyltransferase has a temperature optimum of 25 degrees C, requires the presence of Triton X-100 and either manganese or magnesium for maximal activity, and has Km values for GDP-L-[14-C]fucose and phenyl beta-D-galactoside of 32.1 . 10(-6) M and 8.2 . 10(-3) M, respectively. Guanosine nucleotides are potent inhibitors of the fucosyltransferase reaction; GDP is a competitive inhibitor while, depending on its concentration, GTP can either inhibit or activate the reaction. The alpha-L-fucosidase present in cervical tissue has negligible activity towards the enzyme product, phenyl-alpha-2-L-[14C]fucosyl-beta-D-galactoside. The use of high and low molecular weight acceptors indicates the presence of a beta-N-acetylglucosaminide alpha-3-L-fucosyltransferase and an N-acetylgalactosaminide fucosyltransferase.

Asialoglycoproteins↗
PubMed1983

Fucosyltransferase activities in human lymphocytes and granulocytes. Blood group H-gene-specified alpha-2-L-fucosyltransferase is a discriminatory marker of peripheral blood lymphocytes.

Human lymphocytes and granulocytes were examined for blood group H-gene-specified alpha-2-L-fucosyl-transferase, alpha-3-L-fucosyltransferase and blood group Le-gene-specified alpha-4-L-fucosyltransferase. No alpha-4-L-fucosyltransferase was detectable in either cell type. alpha-3-L-Fucosyltransferase was readily demonstrable in both lymphocytes and granulocytes and the levels of activity per 10(6) cells were approximately the same. In contrast, alpha-2-L-fucosyltransferase was detectable in lymphocytes but not in similar numbers of granulocytes. The absence of alpha-2-L-fucosyltransferase was confirmed in granulocytes isolated from the blood of eighty unselected donors and was independent of ABO blood group or ABH secretor status.

ABO Blood-Group System↗
PubMed1997

Down-regulation of Gal alpha(1,3)Gal expression by alpha1,2-fucosyltransferase: further characterization of alpha1,2-fucosyltransferase transgenic mice.

BACKGROUND: In pig-to-primate transplantation, antibody-mediated hyperacute rejection is the consequence of binding of natural antibodies to Gal alpha(1,3)Gal on pig endothelium. The elimination of the Gal alpha(1,3)Gal antigen from pig cells should prevent hyperacute rejection. Using in vitro techniques, we have previously reported that using the alpha1,2-fucosyltransferase gene induces the preferential expression of H substance with a concomitant reduction in the expression of Gal alpha(1,3)Gal. The aim of the present study was to examine the effect of expressing the alpha1,2-fucosyltransferase gene in vivo on Gal alpha(1,3)Gal. METHODS: Three alpha1,2-fucosyltransferase transgenic lines of mice were produced and characterized serologically and histologically. RESULTS: Immunohistological studies showed heavy staining for H substance in liver, spleen, kidney, and heart, with a reduction in staining for Gal alpha(1,3)Gal. In addition, there was a reduction in the binding of human anti-Gal alpha(1,3)Gal antibody to lymphocytes from alpha1,2-fucosyltransferase transgenic mice and a substantial decrease in complement-mediated cytolysis of alpha1,2-fucosyltransferase transgenic lymphocytes when compared with that obtained with normal mice. CONCLUSIONS: The findings have important implications, in that alpha1,2-fucosyltransferase transgenic pigs could be produced as a source for humans. Such pigs should have a reduced expression of Gal alpha(1,3)Gal.

ABO Blood-Group System↗
PubMed1981

Co-purification of the Lewis blood group N-acetylglucosaminide alpha 1 goes to 4 fucosyltransferase and an N-acetylglucosaminide alpha 1 goes to 3 fucosyltransferase from human milk.

The Lewis blood group-specified N-acetylglucosaminide alpha 1 goes to 4 fucosyltransferase and an N-acetylglucosaminide alpha 1 goes to 3 fucosyltransferase have been copurified over 500,000-fold from human milk by affinity chromatography on GDP-hexanolamine agarose. The purified enzyme preparation migrates as two major bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with apparent Mr = 53,000 and 51,000. Analysis of the acceptor substrate specificity of the transferase(s) and structural characterization of the reaction products indicate that the enzyme(s) forms the Fuc alpha 1 goes to 4GlcNAc, Fuc alpha 1 goes to 3GlcNAc, and Fuc alpha 1 goes to 3Glc linkages with oligosaccharide acceptors containing the nonreducing terminal sequences Gal beta 1 goes to 3GlcNAc, Gal beta 1 goes to 4GlcNAc, and Gal beta 1 goes to 4Glc, respectively. The two fucosyltransferase activities are activated to the same extent by a variety of divalent metal ions, inactivated at identical rates by thermal denaturation or reaction with N-ethylmaleimide, and inhibited to the same extent by rabbit antiserum prepared against the purified fucosyltransferase(s). In addition, kinetic analysis of the initial rate data obtained using acceptors for one of the fucosyltransferase activities as an inhibitor of the second suggests that acceptors for both fucosyltransferase activities bind at a single active site.

Antigen-Antibody Complex↗
PubMed1996

Identification of a GDP-Fuc:Gal beta 1-3GalNAc-R (Fuc to Gal) alpha 1-2 fucosyltransferase and a GDP-Fuc:Gal beta 1-4GlcNAc (Fuc to GlcNAc) alpha 1-3 fucosyltransferase in connective tissue of the snail Lymnaea stagnalis.

Connective tissue of the freshwater pulmonate Lymnaea stagnalis was shown to contain fucosyltransferase activity capable of transferring fucose from GDP-Fuc in alpha 1 -2 linkage to terminal Gal of type 3 (Gal beta 1-3GalNAc) acceptors, and in alpha 1-3 linkage to GlcNAc ot type 2 (Gal beta 1-4GlcNAc) acceptors. The alpha 1-2 fucosyltransferase was active with Gal beta 1-3GalNAc beta 1-OCH2CH=CH2 (Km = 12mM, V(max) = 1.3 mUml-1) and Gal beta 1-3GalNAc (km =20 mM, V(max) = 2.1 mUml-1), whereas the alpha 1-3 fucosyltransferase was active with Gal beta 1-4GlcNAc (Km = 23 mM, V(max) = 1.1 mUml-1). The products formed from from Gal beta 1-3GalNAc beta 1-OCH2CH=CH2 and Gal beta 1-4GlcNAc were purified by high performance liquid chromatography, and identified by 500 MHz 1H-NMR spectroscopy and methylation analysis to be Fucalpha1-2Gal beta 1-3GalNAc beta 1-OCH2CH=CH2 and Gal beta 1-4(Fucalpha1-3)GlcNAc, respectively. Competition experiments suggest that the two fucosyltransferase activities are due to two distinct enzymes.

Animals↗
PubMed1997

Cloning of a rat alpha1,3-fucosyltransferase gene: a member of the fucosyltransferase IV family.

We report the cloning of a rat alpha1,3-fucosyltransferase gene (rFuc-T), isolated from a rat genomic library by a PCR-cross-hybridization based cloning approach using primers derived from the conserved region of human alpha1,3-Fuc-T sequences. Comparison of the rFuc-T predicted amino acid sequence with those of previously cloned human and murine fucosyltransferases showed highest degree of homology to murine Fuc-TIV (87% identity) and human Fuc-TIV (78% identity), with lower homology (41-49% identity) to Fuc-TIII, V, VI, and VII. COS-1 cells transfected with the rFuc-Tgene expressed a fucosyltransferase activity with type 2 (Gal beta1-->4GlcNAc)-containing oligosaccharides and the glycolipid acceptor neolactotetraosylceramide but only low activity with sialylated substrates; the SSEA-1/Le(x) antigen was detected in transfected cells by immunocytochemistry. Based on these results, we surmise that rFuc-T is a member of the fucosyltransferase IV family. Northern blot analysis with a rFuc-T specific probe indicated a major transcript of 4.2 kb most abundantly expressed in rat spleen; minor transcripts of different sizes were detected in several tissues, including rat brain.

Amino Acid Sequence↗
PubMed1996

Molecular cloning and expression of a mouse alpha-1,3 fucosyltransferase gene that shows homology with the human alpha-1,3 fucosyltransferase IV gene.

The polymerase chain reaction was used to amplify and clone a fragment of a novel fucosyltransferase cDNA from mouse embryonal carcinoma F9 cells. Southern blot analysis of mouse genomic DNA with the cloned cDNA fragment revealed that there is a single copy of the fucosyltransferase gene per haploid genome. A 5 kb EcoRI restriction fragment of the genomic DNA hybridized with the cDNA has been cloned and a 1,697 bp fragment containing the sequence of the cDNA was sequenced. The nucleotide sequence and the deduced amino acid sequence of the clone showed a highest degree of homology with those of human alpha-1,3 fucosyltransferase IV, i.e. 77.1 and 75.5% identity, respectively. Consistent with the sequence similarity, the transfection of a 1,544 bp fragment under the control of the cytomegarovirus enhancer and beta actin promoter into COS-1 cells confers alpha-1,3 fucosyltransferase activity on the cells, resulting in cell surface expression of SSEA-1.

Amino Acid Sequence↗
PubMed1993

Human alpha-1,3 fucosyltransferase (FucT-VI) gene is located at only 13 kb 3' to the Lewis type fucosyltransferase (FucT-III) gene on chromosome 19.

Human alpha-(1.3/1,4) fucosyltransferase (FucT-III) gene and alpha 1,3 fucosyltransferase (FucT-VI) gene were found in the 38-kb fragment isolated from a human cosmid library. These genes were present 13 kb apart in tandem orientation. The FucT-III gene has already been mapped on the Lewis locus of chromosome 19. This demonstrated that FucT-VI gene was localized close to the Lewis locus on chromosome 19.

Base Sequence↗
PubMed2001

CD15 expression in mature granulocytes is determined by alpha 1,3-fucosyltransferase IX, but in promyelocytes and monocytes by alpha 1,3-fucosyltransferase IV.

The CD15 carbohydrate epitope is expressed in mature human neutrophils, monocytes, and promyelocytes. We aimed to determine the alpha1,3-fucosyltransferase responsible for the expression of CD15 in each subpopulation of leukocytes. Three alpha1,3-fucosyltransferases, FUT4, FUT7, and FUT9, are expressed in human leukocytes. We demonstrated that FUT9 exhibits 20-fold stronger activity for CD15 synthesis than FUT4, whereas FUT4 exhibits 4.5-fold stronger activity for CDw65 synthesis than FUT9. By competitive reverse transcriptase-polymerase chain reaction, FUT9 was found to be strongly expressed in mature granulocytes and peripheral blood mononuclear cell, but not in monocytes. CD34(+) and CD15(+) cells in cord blood and myeloid cell lines (HL-60 and U937) did not express FUT9 at all. FUT4 transcripts were ubiquitously expressed in all blood cells and all cultured cell lines, with HL-60 and U937 cells in particular expressing a number of FUT4 transcripts. Transfection of the FUT9 gene into Jurkat and U937 cells demonstrated that FUT9 has the potential to express CD15 in myeloid and lymphoid cells. These findings suggest that the expression of CD15 in mature granulocytes is directed by FUT9, whereas it is determined in promyelocytes and monocytes by FUT4. Measurement of CD15 synthesizing activity in cell homogenates of each cell population using the polylactosamine acceptor further supported these conclusions.

Antigens, CD↗
PubMed2000

Ancestral exonic organization of FUT8, the gene encoding the alpha6-fucosyltransferase, reveals successive peptide domains which suggest a particular three-dimensional core structure for the alpha6-fucosyltransferase family.

Based on PCR strategies and expression studies, we define the genomic organization of the FUT8b gene. This gene encodes the only known mammalian enzyme transferring fucose in an alpha1-->6 linkage on the asparagine-branched GlcNAc residue of the chitobiose unit of complex N:-glycans. The intron/exon organization of the bovine coding sequence determines five successive functional domains. The first exon encodes a domain homologous to cytoskeleton proteins, the second presents a proline-rich region including a motif XPXPPYXP similar to the peptide ligand of the SH3-domain proteins, the third encodes a gyrase-like domain (an enzyme which can bind nucleotides), and the fourth encodes a peptide sequence homologous to the catalytic domain of proteins transferring sugars. Finally, the last exon encodes a domain homologous to the SH3 conserved motif of the SH2-SH3 protein family. This organization suggests that intramolecular interactions might give a tulip-shaped scaffolding, including the catalytic pocket of the enzyme in the Golgi lumen. Deduced from the published sequence of chromosome 14 (AL109847), the human gene organization of FUT8 seems to be similar to that of bovine FUT8b, although the exon partition is more pronounced (bovine exons 1 and 2 correspond to human exons 1-6). The mosaicism and phylogenetic positions of the alpha6-fucosyltransferase genes are compared with those of other fucosyltransferase genes.

Amino Acid Sequence↗
PubMed1998

Identification of an alpha3-fucosyltransferase and a novel alpha2-fucosyltransferase activity in cercariae of the schistosome Trichobilharzia ocellata: biosynthesis of the Fucalpha1-->2Fucalpha1-->3[Gal(NAc)beta1-->4]GlcNAc sequence.

Fucose is a major constituent of the protein- and lipid-linked glycans of the various life-cycle stages of schistosomes. These fucosylated glycans are highly antigenic and seem to play a role in the pathology of schistosomiasis. In this article we describe the identification and characterization of two fucosyltransferases (FucTs) in cercariae of the avian schistosome Trichobilharzia ocellata, a GDP-Fuc:[Galbeta1-->4]GlcNAcbeta-R alpha1-->3-FucT and a novel GDP-Fuc:Fucalpha-R alpha1-->2-FucT. Triton X-100 extracts of cercariae were assayed for FucT activity using a variety of acceptor substrates. Type 1 chain (Galbeta1-->3GlcNAc) based compounds were poor acceptors, whereas those based on a type 2 chain (Galbeta1-->4GlcNAc), whether alpha2'-fucosylated, alpha3'-sialylated, or unsubstituted, and whether present as oligosaccharide or contained in a glycopeptide or glycoprotein, all served as acceptor substrates. In this respect the schistosomal alpha3-FucT resembles human FucT V and VI rather than other known FucTs. N-ethylmaleimide, an inhibitor of several human FucTs, had no effect on the activity of the schistosomal alpha3-FucT, whereas GDP-beta-S was strongly inhibitory. Large scale incubations were carried out with Galbeta1-->4GlcNAc, GalNAcbeta1-->4GlcNAcbeta-O -(CH2)8COOCH3 and Fucalpha1-->3GlcNAcbeta1-->2Man as acceptor substrates and the products of the incubations were isolated using a sequence of chromatographic techniques. By methylation analysis and 2D-TOCSY and ROESY1H-NMR spectroscopy the products formed were shown to be Galbeta1-->4[Fucalpha1-->2Fucalpha1-->3]GlcNAc, GalNAcbeta1-->4[Fucalpha1-->2Fucalpha1-->3]GlcNAcbe ta-O-(CH2)8COOCH3, and Fucalpha1-->2Fucalpha1-->3GlcNAcbeta1-->2Man, respectively. It is concluded that the alpha2-FucT and alpha3-FucT are involved in the biosynthesis of the (oligomeric) Lewisx sequences and the Fucalpha1-->2Fucalpha1-->3GlcNAc structural element that have been described on schistosomal glycoconjugates.

Animals↗
PubMed1990

Transfection of a human alpha-(1,3)fucosyltransferase gene into Chinese hamster ovary cells. Complications arise from activation of endogenous alpha-(1,3)fucosyltransferases.

In order to isolate a human gene encoding an alpha-(1,3)fucosyltransferase (alpha-(1,3)Fuc-T), genomic DNA from HL-60 cells was transfected by several methods into Chinese hamster ovary (CHO) cells. Colonies expressing alpha-(1,3)Fuc-T activity were identified by their ability to bind a monoclonal antibody (anti-SSEA-1) that recognizes the carbohydrate product of alpha-(1,3)Fuc-T action. CHO cells do not express alpha-(1,3)Fuc-T activity but contain at least two, silent alpha-(1,3)Fuc-T genes previously identified by their activation in the rare, dominant mutants LEC11 and LEC12. These CHO enzymes were shown to be distinguishable from the alpha-(1,3)Fuc-T activity of HL-60 cells by the latter's comparative inability to transfer fucose to paragloboside and fetuin. Based on these criteria, only 11 isolates from more than 70 putative transfectants examined were found to stably express an alpha-(1,3)Fuc-T activity typical of HL-60 cells. Genomic DNA from two of these isolates was used to generate five independent secondary transfectants with HL-60-like alpha-(1,3)Fuc-T activity. Southern analysis revealed a common DNA fragment that hybridized to an Alu probe in each secondary, providing evidence that a human alpha-(1,3)Fuc-T gene had been transfected. However, in all transfection experiments, isolates that expressed alpha-(1,3)Fuc-T activities similar to CHO-encoded enzymes were also obtained. Several lines of evidence indicated that these cells arose from activation of endogenous CHO alpha-(1,3)Fuc-T genes as a consequence of DNA transfection. These false positives complicated the identification of transfectants expressing a human alpha-(1,3)Fuc-T gene and represent an important consideration in experiments to transfect other glycosyltransferase genes.

Animals↗
PubMed1999

Stage-specific expression of alpha1,2-fucosyltransferase and alpha1, 3-fucosyltransferase (FT) during mouse embryogenesis.

Lex [Galbeta1-4(Fucalpha1-3)GlcNAc] and Ley [Fucalpha1-2Galbeta1-4(Fucalpha1-3)GlcNAc] are both stage-specific embryonic antigens. Lex is first detected on the blastomeres of the 8-cell stage embryo, which correlates with the onset of blastomere compaction. Ley is highly expressed on the surface of the blastocyst, which has been shown to be involved in blastocyst attachment in the mouse. In the present study, mouse alpha1,2-FT (also known as FUT1) and alpha1,3-FT (also known as Fuc-TIV), which were responsible for Lex and Ley formation, were examined in preimplantation stage embryos by reverse transcription-PCR and in situ hybridization. alpha1,3-FT mRNA was detected in all embryos of preimplantation stage, while alpha1,2-FT mRNA emerged in the later stage embryos from 8-cell to 16-cell to the blastocyst. These results indicated the expression of Ley was regulated by alpha1,2-FT. In situ hybridization showed that these two enzyme mRNAs were detected only in morula and blastocyst stage embryos. The alpha1,2-FT and alpha1, 3-FT mRNAs were located in both the inner cell mass and the trophoblast cells. 2-Cell and 4-cell embryos were isolated from the oviduct and cultured in vitro to the 8-cell, morula and blastocyst stage. The expression of alpha1,2-FT and alpha1,3-FT were observed in these embryos developed in vitro; immunohistochemical analysis also showed that Ley expression was positive. These results suggested the stage-specific expression of Ley on the embryos was synthesized by endogenous alpha1,2-FT and alpha1,3-FT rather than transfer from other sources. In addition, the expression of alpha1, 2-FT was differentially regulated and the uterine factor was not prerequisite of the expression of Ley.

Animals↗