OBJECTIVEUsing nested polymerase chain reaction (PCR) to perform preimplantation gender diagnosis.

METHODSOne (or two) lymphocyte and blastomere (n=50/group) were collected and prepared under the following conditions: (1) water only (H(2)O); (2) freeze-thaw liquid nitrogen, then boiling; (3) potassium hydroxide/dithiotheriol, heated to 65 degree centigrade, followed by acid neutralization (KOH). Cells were analyzed by PCR using nested primers amplification with amelogenin gene.

RESULTSThe amplification rate and allele dropout (ADO) rate for male lymphocytes by the three methods were 83%, 94%, 95% and 24%, 12%, 4%, respectively. Using two cells per reaction did not increase the amplification rate for the KOH method.

CONCLUSIONThe KOH method for DNA preparation is superior to the other methods evaluated. Dual blastomere biopsy and independent blastomere analysis may improve preimplantation diagnostic reliability.

Amelogenin ; Blastocyst ; cytology ; metabolism ; Blastomeres ; cytology ; metabolism ; DNA ; genetics ; Dental Enamel Proteins ; genetics ; Female ; Genotype ; Humans ; Lymphocytes ; cytology ; metabolism ; Male ; Polymerase Chain Reaction ; methods ; Sex Determination Analysis ; methods

OBJECTIVE: To detect two exons of Duchenne muscular dystrophy (DMD) gene and a gender discrimination locus amelogenin gene by single cell triplex PCR, and to evaluate the possibility of this technique for preimplantation genetic diagnosis (PGD) in DMD family with DMD deletion mutation. METHODS: Single lymphocytes from a normal male, a normal female, two DMD patients (exon 8 and 47 deleted, respectively) and single blastomeres from the couples treated by the in vitro fertilization pre-embryo transfer (IVF-ET) and without family history of DMD were obtained. Exons 8 and 47 of DMD gene were amplified by a triplex PCR assay, the amelogenin gene on X and Y chromosomes were co-amplified to analyze the correlation between embryo gender and deletion status. RESULTS: In the normal single lymphocytes, the amplification rate of exons 8 and 47 of DMD and amelogenin gene were 93.8%, 93.8%, and 95.3% respectively. The false positive rate was 3.3%. In the exon 8 deleted DMD patient, the amplification rate of exon 47 of DMD and amelogenin gene was 95.8%, and the false positive rate was 3.3%. In the exon 47 deleted DMD patient, the amplification rate of exon 8 of DMD and amelogenin gene was 95.8%, and the false positive rate was 0. In the single blastomeres, the amplification rate of exons 8 and 47 of DMD and amelogenin gene was 82.5%, 80.0% and 77.5%, respectively, and the false positive rate was 0. CONCLUSION The single cell triplex PCR protocol for the detection of DMD and amelogenin gene is highly sensitive, specific and reliable, and can be used for PGD in those DMD families with DMD deletion mutation.
Amelogenin ; genetics ; Blastomeres ; cytology ; metabolism ; Chromosomes, Human, X ; genetics ; Chromosomes, Human, Y ; genetics ; Cytogenetic Analysis ; methods ; Exons ; genetics ; Female ; Gene Deletion ; Humans ; Lymphocytes ; cytology ; metabolism ; Male ; Muscular Dystrophy, Duchenne ; blood ; diagnosis ; genetics ; Polymerase Chain Reaction ; methods ; Pregnancy ; Preimplantation Diagnosis ; methods

In order to research developmental competence of transgenic somatic cell by serial nuclear transplantation, goat cloned embryos were compared with recloned embryos in ability of in vitro development. Fetal fibroblasts including human finger-domain lacking t-PA gene was microinjected into cytoplasm of the MII oocytes. Goat embryos (G0) were cloned by this procedure. A single blastomere from 16 - 64-cell goat cloned embryos (G0) was microinjected into Intracytoplasm of the MII oocytes. Goat embryos (G) were cloned by this procedure. Goat embryos (G2, G3) were recloned by using 16 - 64-cell recloned embryos. The developmental time of donor embryo affected the developmental rate of recloned embryos (G1, G2). The results show: the cleavage rate of cloned embryos (G0) (76.45% +/- 1.17%) was no difference significantly with recloned embryos (G1 G2 G3) (72.18% +/- 1.97%, 76.05% +/- 2.38%, 75.99% +/- 2.84%); the developmental rate of morulae and blastocysts of cloned embryos (47.20% +/- 2.93%, 11.00% +/- 1.42%) were higher than these of recloned embryos(34.99% +/- 2.66%, 28.23% +/- 2.00%, 23.34% +/- 1.99%) (3.87% +/- 0.67%, 2.08% +/- 1.66%, 0); the morulae rate(29.57% +/- 1.53%, 24.43% +/- 1.87%) and blastocysts rate(1.96% +/- 1.31%, 2.01% +/- 1.34%) of recloned embryos (G1 G2) from 16-cell recloned embryos were lower than those(34.32% +/- 1.31%, 29.76% +/- 1.66% and 3.86% +/- 1.03%, 3.48% +/- 0.34% )from 32 - 64-cell recloned embryos (P > 0.05). In conclusion, nuclear transfer embryos should not were recloned mostly; and the embryos recloned by using 32 - 64-cell embryos achieved higher developmental ability compared with using 16-cell embryos.
Animals ; Animals, Genetically Modified ; Blastomeres ; cytology ; physiology ; Cloning, Organism ; methods ; veterinary ; Embryo Culture Techniques ; Embryo, Mammalian ; cytology ; Female ; Fibroblasts ; cytology ; Gene Deletion ; Goats ; Humans ; Nuclear Transfer Techniques ; veterinary ; Oocytes ; cytology ; physiology ; Pregnancy ; RING Finger Domains ; genetics ; physiology ; Tissue Plasminogen Activator ; genetics ; metabolism

Wnt signaling is known to be important for diverse embryonic and post-natal cellular events and be regulated by the proteins Dishevelled and Axin. Although Dishevelled is activated by Wnt and involved in signal transduction, it is not clear how Dishevelled-mediated signaling is turned off. We report that guanine nucleotide binding protein beta 2 (Gnb2; Gbeta2) bound to Axin and Gbeta2 inhibited Wnt mediated reporter activity. The inhibition involved reduction of the level of Dishevelled, and the Gbeta2gamma2 mediated reduction of Dishevelled was countered by increased expression of Axin. Consistent with these effects in HEK293T cells, injection of Gbeta2gamma2 into Xenopus embryos inhibited the formation of secondary axes induced either by XWnt8 or Dishevelled, but not by beta-catenin. The DEP domain of Dishevelled is necessary for both interaction with Gbeta2gamma2 and subsequent degradation of Dishevelled via the lysosomal pathway. Signaling induced by Gbeta2gamma2 is required because a mutant of Gbeta2, Gbeta2 (W332A) with lower signaling activity, had reduced ability to downregulate the level of Dishevelled. Activation of Wnt signaling by either of two methods, increased Frizzled signaling or transient transfection of Wnt, also led to increased degradation of Dishevelled and the induced Dishevelled loss is dependent on Gbeta1 and Gbeta2. Other studies with agents that interfere with PLC action and calcium signaling suggested that loss of Dishevelled is mediated through the following pathway: Wnt/Frizzled-->Gbetagamma-->PLC-->Ca+2/PKC signaling. Together the evidence suggests a novel negative feedback mechanism in which Gbeta2gamma2 inhibits Wnt signaling by degradation of Dishevelled.
Adaptor Proteins, Signal Transducing/genetics/*metabolism ; Animals ; Blastomeres/cytology/*metabolism ; Cell Line ; Embryonic Development/genetics ; *Feedback, Physiological ; Frizzled Receptors/genetics/metabolism ; GTP-Binding Proteins/genetics/*metabolism ; Gene Expression Regulation, Developmental ; Humans ; Mutation ; Phosphoproteins/genetics/*metabolism ; Protein Binding ; RNA, Small Interfering/genetics ; Repressor Proteins/genetics/metabolism ; Transfection ; Wnt Proteins/*genetics/metabolism ; Xenopus ; Xenopus Proteins/*genetics/metabolism

β-Thalassemia is a global health issue, caused by mutations in the HBB gene. Among these mutations, HBB -28 (A>G) mutations is one of the three most common mutations in China and Southeast Asia patients with β-thalassemia. Correcting this mutation in human embryos may prevent the disease being passed onto future generations and cure anemia. Here we report the first study using base editor (BE) system to correct disease mutant in human embryos. Firstly, we produced a 293T cell line with an exogenous HBB -28 (A>G) mutant fragment for gRNAs and targeting efficiency evaluation. Then we collected primary skin fibroblast cells from a β-thalassemia patient with HBB -28 (A>G) homozygous mutation. Data showed that base editor could precisely correct HBB -28 (A>G) mutation in the patient's primary cells. To model homozygous mutation disease embryos, we constructed nuclear transfer embryos by fusing the lymphocyte or skin fibroblast cells with enucleated in vitro matured (IVM) oocytes. Notably, the gene correction efficiency was over 23.0% in these embryos by base editor. Although these embryos were still mosaic, the percentage of repaired blastomeres was over 20.0%. In addition, we found that base editor variants, with narrowed deamination window, could promote G-to-A conversion at HBB -28 site precisely in human embryos. Collectively, this study demonstrated the feasibility of curing genetic disease in human somatic cells and embryos by base editor system.
APOBEC-1 Deaminase ; genetics ; metabolism ; Base Sequence ; Blastomeres ; cytology ; metabolism ; CRISPR-Cas Systems ; Embryo, Mammalian ; metabolism ; pathology ; Female ; Fibroblasts ; metabolism ; pathology ; Gene Editing ; methods ; Gene Expression ; HEK293 Cells ; Heterozygote ; Homozygote ; Humans ; Point Mutation ; Primary Cell Culture ; Promoter Regions, Genetic ; Sequence Analysis, DNA ; beta-Globins ; genetics ; metabolism ; beta-Thalassemia ; genetics ; metabolism ; pathology ; therapy