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Y Verlinsky

Publications and source records attributed to Y Verlinsky.

At least 73 records · Page 4Linked to original sources
PubMed1996

Birth of a healthy girl after preimplantation gender determination using a combination of polymerase chain reaction and fluorescent in situ hybridization analysis. Preimplantation Genetics Group.

OBJECTIVE: To perform preimplantation gender determination by a combination of polymerase chain reaction (PCR) sexing and fluorescent in situ hybridization technique using the directly labeled fluorescent alpha-satellite centromeric DNA probes for X and Y chromosomes. SETTING: The IVF program of Illinois Masonic Medical Center. PATIENTS: A couple requested preimplantation diagnosis because the mother is a carrier for hemophilia A. RESULTS: Two blastomeres were aspirated from each of the four- to eight-cell embryos, and only the embryos with both fluorescent in situ hybridization and PCR results indicating female sex chromosomal complement were transferred, resulting in a singleton pregnancy and delivery of a healthy female infant, after prenatal confirmation of the diagnosis as female. The male embryos or embryos diagnosed as females only by PCR were followed up by confirmatory fluorescent in situ hybridization analysis demonstrating a discrepancy of PCR and fluorescent in situ hybridization results in four embryos, presumably because of a possible sperm contamination of the PCR reaction or chromosomal mosaicism. CONCLUSION: The analysis of two blastomeres from the same embryo by a combination of PCR sexing and fluorescent in situ hybridization increases the reliability of preimplantation gender identification at the cleavage stage.

Adult↗
PubMed1996

Birth of healthy children after preimplantation diagnosis of common aneuploidies by polar body fluorescent in situ hybridization analysis. Preimplantation Genetics Group.

OBJECTIVE: To perform preimplantation diagnosis of common aneuploidies by polar body analysis and fluorescent in situ hybridization technique using probes specific for chromosomes X, 18, and 13/21. DESIGN: The first and/or second polar bodies were removed and studied by fluorescent in situ hybridization to detect and avoid fertilization and transfer of oocytes with common aneuploidies. SETTING: The Reproductive Genetics Institute's IVF program at Illinois Masonic Medical Center. PATIENTS: One hundred ninety-three couples of advanced maternal age (34 to 46 years) under-going IVF treatment volunteered to be part of a clinical trial on preimplantation polar body diagnosis of common aneuploidies. INTERVENTIONS: Using micromanipulation procedures, the first and second polar bodies were removed after their extrusion from the oocytes. MAIN OUTCOME MEASURE: Fluorescent in situ hybridization signals specific for chromosomes X, 18, and 13/21. RESULTS: In 235 IVF cycles performed in 193 couples, 1,293 oocytes were biopsied and subjected to fluorescent in situ hybridization analysis, with fluorescent in situ hybridization results available in 993 oocytes (76.8%). Of 993 oocytes with fluorescent in situ hybridization results, 665 (67%) were predicted to be normal based on the chromosomes studied; 460 embryos resulting from these oocytes were transferred in 187 treatment cycles, resulting in 12 births of healthy children and 18 ongoing pregnancies after confirmation of the polar body diagnosis by chorionic villus sampling or amniocentesis. CONCLUSION: Polar body fluorescent in situ hybridization analysis may be used for preimplantation diagnosis of common aneuploidies in IVF patients of advanced maternal age.

Adult↗
PubMed1995

Homeobox gene expression in human oocytes and preembryos.

Homeobox gene expression in human preimplantation development has not been established. We used reverse transcriptase-polymerase chain reaction (RT-PCR) with intron spanning primer sets to investigate the presence of mRNA of homeobox genes in human oocytes and preembryos. RT-PCR products obtained from normal and unfertilized oocytes, from cleaving normal and triploid embryos, and from morulae and blastocysts were cloned, sequenced, and analyzed for the presence of homeobox sequences. The presence of mRNA of homeoboxes HoxA4 and HoxA7 was demonstrated; HoxA4 was present in normal and unfertilized oocytes and also in a 4-cell embryo. HoxA7 was present in normal oocytes and cleaving triploid embryos.

Amino Acid Sequence↗
PubMed1995

Cross-hybridization of the chromosome 13/21 alpha satellite DNA probe to chromosome 22 in the prenatal screening of common chromosomal aneuploidies by FISH.

In a routine application of commercially available centromeric DNA probes for the prenatal screening of common trisomies involving the autosomes 13, 18, and 21, and sex chromosomes, four cases of discrepancy between fluorescence in situ hybridization (FISH) results and follow-up cytogenetic analysis were observed from a total of 516 cases of amniocentesis. In three of these cases, the results were false negative, and in one false positive. In this case, amniocentesis was performed because of a positive triple test in a 34-year-old woman with previous infertility treatment. The alpha satellite DNA probe for chromosomes 13/21 revealed five signals in 50 per cent of uncultured amniocytes, while standard cytogenetic analysis showed a normal karyotype. FISH analysis on metaphase chromosomes demonstrated the location of the additional signal in the centromeric region of chromosome 22. This additional signal was also present in the centromeric region of chromosome 22 of the mother, providing evidence for a possible inherited polymorphism in chromosome 22 responsible for unspecific hybridization with the alpha satellite probe for chromosomes 13/21 in this case. The observed polymorphism in centromeric regions may contribute to unreliability of the use of the 13/21 alpha satellite probe for prenatal screening by FISH.

Adult↗
PubMed1995

Viability of embryos following second polar body removal in a mouse model.

PURPOSE: Our purpose was to evaluate the effect of the second polar body removal on the viability and development potential of the resulting embryos. METHOD: The second polar body was removed in 343 mouse oocytes and the development potential of the resulting embryos was compared in vitro to that in 223 intact mouse embryos and 222 controls which were placed under the same conditions as those micromanipulated. RESULTS: The proportion of morphologically normal blastocysts formed by polar body biopsied oocytes (70.8%) was not significantly different from that obtained from the control (81.1%) and intact (85%) oocytes. Cell counts of blastocysts obtained from the manipulated and non-manipulated oocytes were also not statistically different. CONCLUSION: The second polar body biopsy does not have a significant adverse effect on preimplantation development and may be applied for genetic evaluation of oocytes.

Animals↗
PubMed1995

Pregnancies following pre-conception diagnosis of common aneuploidies by fluorescent in-situ hybridization.

Chromosomal aneuploidies contribute considerably to the low pregnancy rate in in-vitro fertilization (IVF). The objective of this experimental work was to explore the possibility of detecting common aneuploidies in oocytes by polar body sampling. The study included 45 infertile patients of advanced maternal age participating in an IVF programme. The first polar body was removed prior to fertilization or both the first and second polar bodies were removed after fertilization and studied by fluorescent in-situ hybridization (FISH) using chromosome-specific probes for chromosomes X, 18 and/or 13/21. Of 155 oocytes with FISH results, 36 demonstrated chromosomal abnormalities. Of 119 oocytes predicted to be free from aneuploidy of chromosomes X, 18 and/or 13/21, 72 were normally fertilized, cleaved and transferred in 23 treatment cycles, which resulted in two healthy deliveries and three ongoing pregnancies confirmed to be unaffected by chorionic villous sampling. The method may appear useful for the detection of oocytes with common chromosomal aneuploidies in IVF patients of advanced maternal age.

Adult↗
PubMed1994

Review: borders, patterns, and distinctive families of homeodomains.

PURPOSE: Homeotic proteins function as transcription factors in early embryogenesis of many organisms. To date, hundreds of distinctive homeoproteins have been identified, including 84 human homeodomains. However further progress in understanding functional relationships between particular homeoproteins and other embryonic regulators requires a comprehensive structural classification of these proteins. RESULTS: The most probable borders and conservative amino acid positions inside the homeodomain region have been established using a statistical analysis of variabilities of amino acid occurrences at various positions outside and inside the domain. A new format for a homeodomain sequence presentation and regular amino acid patterns which are strongly representative of distinctive homeodomain groups are proposed. Using the established patterns, 33 families of closely related homeodomains have been distinguished and classified. The total list of 297 homeodomain amino acid sequences is presented in the Appendix. CONCLUSION: The structural classification of homeodomains has been proposed. It can be useful for both the identification (or prediction) of new homeotic genes/proteins and the recognition of possible PCR-induced sequence errors. This systematics will also have an impact on understanding functional relationships among homeotic proteins and other genetic regulators of developmental processes.

Amino Acid Sequence↗
PubMed1994

Reliability of polymerase chain reaction (PCR) analysis of single cells for preimplantation genetic diagnosis.

PURPOSE: We investigated the reliability of polymerase chain reaction (PCR) genotype analyses performed on single cells for the purposes of preimplantation genetic analysis. METHODS: We performed blind analysis of 130 single skin fibroblasts heterozygous for the delta-F508 mutation in the cystic fibrosis transmembrane regulator (CFTR) gene and 73 single skin fibroblasts from an individual heterozygous for the XbaI polymorphic site of the Factor VIII gene. RESULTS: Amplification was successful for 116 cells and 52 cells respectively and in all but one case (a CFTR analysis) both alleles were amplified. The incidence of diagnostic error was 1 out of 203 analyses or 0.0043. We conclude that PCR is a reliable method for determining the genotype of single cells for the purposes of preimplantation genetic analysis.

Alleles↗
PubMed1994

Visualization and cytogenetic analysis of second polar body chromosomes following its fusion with a one-cell mouse embryo.

PURPOSE: This study was designed to visualize the second polar body (2PB) chromosomes using its electrofusion with a one-cell-stage mouse embryo to approach preconception diagnosis of chromosomal disorders. RESULTS: Eighty to 90% hybridization efficiency has been achieved by electrofusion of 2PB with mouse zygotes. 2PB chromosomes were visualized in 40-50% of hybrids. Sixty-five percent of 2PB chromosomes were visualized when fused with the cytoplast obtained microsurgically by removing pronuclei from a one-cell embryo. As much as 33-43% of these resulting metaphases appeared to contain chromosomal aberrations. The follow-up of the development of the reconstructed one cell-stage hybrids in vitro revealed a significant decrease in their viability. The hybrid embryos resulting from 2PB electrofusion with enucleated zygotes did not develop beyond the two-cell stage. CONCLUSION: Electrofusion is an efficient approach for hybridization of 2PB with a one-cell mouse embryo and may be useful for visualization and cytogenetic analysis of 2PB chromosomes. The visualization rate of 2PB chromosomes is higher if 2PB is fused with enucleated zygotes. However, the method induces over 30% of chromosomal aberrations and may lead to a significant decrease in the viability of the resulting one-cell embryos.

Animals↗
PubMed1994

Human preimplantation diagnosis: needs, efficiency and efficacy of genetic and chromosomal analysis.

One of the limitations of existing assisted reproduction practices is that couples at genetic risk to their offspring have to face the abortion of an affected fetus following prenatal diagnosis. This is not acceptable as a measure to avoid a congenital disease in many communities or ethnic groups, where there is a great need for a method to diagnose and avoid the affected embryo before implantation and establishment of the pregnancy. In fact, preimplantation diagnosis is needed also for those who accept prenatal diagnosis as an option to avoid the birth of an affected child, because in most of the cases the couples are at high (25-50%) risk of having a child with a recessive or dominant disease, leading to their unfortunate experience of undergoing two or more abortions of wanted pregnancies. Two methods for preimplantation genetic diagnosis (PGD) have been recently developed and implemented in the framework of IVF. PGD can be performed by micromanipulation and biopsy of the first polar body before fertilization, or by blastomere biopsy before implantation of the pre-embryo. Another potentially realistic approach is blastocyst biopsy, which is still under development and has not yet been tested in clinical practice. Available data suggest that preimplantation diagnosis is safe, as no detrimental effects have been observed in studies on the viability of biopsied pre-embryos. Genetic analysis of biopsied gametes and blastomeres is now possible by DNA analysis, while enzyme analysis and preimplantation diagnosis of chromosomal disorders are still at the research stage. The accuracy of DNA analysis in preimplantation diagnosis is clear from available data on the outcome of preimplantation diagnosis: eight children free of genetic disease have been born following preimplantation diagnosis of cystic fibrosis, haemophilia A and other X-linked conditions. However, two misdiagnoses have been also described, showing the need for further development and improvement in the accuracy, efficiency and efficacy of DNA analysis in single cells. A particularly important implication for assisted reproduction practices can be expected from the further development and improvement of methods for preimplantation cytogenetic analysis. Although the efficiency and efficacy of these methods are not yet acceptable for application in clinical practice, considerable progress has been made, providing clear evidence for their feasibility in the near future. In spite of the high cost of the preimplantation diagnostic technique at present, its development is highly justified for high risk families as it provides a wider range of options for avoiding the risk of having an affected child.(ABSTRACT TRUNCATED AT 400 WORDS)

Blastomeres↗
PubMed1993

Okadaic acid induces premature chromosome condensation reflecting the cell cycle progression in one-cell stage mouse embryos.

Haploid parthenogenetic embryos as well as fertilized mouse eggs were treated in vitro with 1-10 microM okadaic acid (OA) at the one-cell stage. Cytogenetic analysis detected that OA induces nuclear envelope breakdown (NEBD) and premature condensation of interphase chromosomes in pronuclei as well as in 2nd polar body (PB) nuclei. G1-, S-, and G2-type prematurely condensed chromosomes (PCC) were found in pronuclei of embryos of different age, which reflects their progression through the first cell cycle. In nuclei from 2nd PBs only G1- and S-type PCC were observed. Using the types of PCC as a criterion of different phases of the cell cycle, it was possible to estimate that in haploid parthenogenetic embryos G1-phase lasts until 5.5 hr post activation (hpa), S-phase takes from 4.5 to 9.5 hpa, and from 8.5 hpa G2-phase had started. Second PBs were found to be in G1-phase until 6.5 hpa and S-phase started in some as early as 5.5 hpa, but in most not before 7.5 hpa. Treatment with OA visualizes G1-chromosomes in pronuclei as well as in 2nd PBs, and it is easy to count the number of these chromosomes and recognize a T6 marker chromosome. The possibility to apply cytogenetic analysis of G1-chromosomes from 2nd PBs for a more accurate detection of maternal meiotic nondisjunction is discussed.

Animals↗
PubMed1992

Preconception and preimplantation diagnosis for cystic fibrosis.

Preimplantation diagnosis provides couples at high genetic risk the possibility of avoiding genetic disease without the need for prenatal diagnosis and selective abortion of the affected pregnancy. Following extensive background work on the reliability of genetic diagnosis in a single cell, we offered on a research basis preimplantation diagnosis to five couples at risk for offspring with the delta-F508 mutation (the major mutation causing cystic fibrosis). There was no detrimental effect from polar body removal on either fertilization or preimplantation development. Genetic analysis, undertaken in 22 polar bodies and 15 corresponding blastomeres, identified 21 embryos of which ten were transferred.

Biopsy↗