Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A reverse transcriptase-polymerase chain reaction assay (RT-PCR) was used quantitatively to measure accumulated levels of RNA transcripts in total mouse RNAs derived from male germ cells at various spermatogenic stages. RNA levels for two X-linked enzymes, phosphoglycerate kinase (PGK-1) and hypoxanthine phosphoribosyl transferase (HPRT), both decrease during spermatogenesis, although the transcript levels decrease much more rapidly for PGK-1. RNA for the Y-linked ZFY (zinc finger protein) is elevated in all spermatogenic cell fractions tested, being particularly high in leptotene/zygotene spermatocytes and round spermatids. RNA for adenine phosphoribosyltransferase (APRT) increases 5-fold to a peak during late pachynema. RNA for PGK-2, undetectable in spermatogonial cells, increases at least 50-fold by the round spermatid stage. DNA (cytosine-5-)-methyltransferase (MTase) transcript levels are over an order of magnitude higher throughout spermatogenesis than in non-dividing liver cells.
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PMID:Measurement by quantitative PCR of changes in HPRT, PGK-1, PGK-2, APRT, MTase, and Zfy gene transcripts during mouse spermatogenesis. 169 Aug 74

The terminal portion of the short arm of the human Y (Yp) chromosome encodes a zinc-finger DNA binding protein (ZFY). A highly homologous gene, ZFX, is encoded on Xp. The potential of the zinc finger motif for regulating the expression of other genes suggests a role for this protein in the development of malignancy. Prostate adenocarcinoma is a malignancy of male-specific tissue, the incidence of which increases beyond the fifth decade of life. We have analyzed samples of human prostate adenocarcinoma for the expression of ZFY and ZFX transcripts. We found expression of ZFY transcripts in 3 of 31 prostate adenocarcinomas by using Northern analysis. No ZFY or ZFX transcripts were detected in normal hypertrophic prostate tissue on Northern analysis. In one prostate adenocarcinoma, high levels of the 5.1 kb ZFY and the 8.0 and 6.3 kb ZFX transcripts were present. In addition, this high-grade tumor contained a novel 4.3 kb transcript. When we used reverse transcriptase PCR (RT-PCR) to analyze these same samples, the number of tumors expressing ZFY and/or ZFX transcripts increased to 20 of 31. Transcripts for these genes were also present in the DU-145 and LNCaP human prostate adenocarcinoma cell lines. In 2 of the 6 benign prostatic hypertrophy (BPH) tissues analyzed by RT-PCR, barely detectable products of ZFY were observed, and none contained ZFX products. Southern analysis revealed that the portion of the Y chromosome which contains the ZFY gene was not lost from the majority of the tumor cells in any of the prostate malignancies examined.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:ZFY gene expression and retention in human prostate adenocarcinoma. 768 Aug 90

Global activation of the embryonic genome occurs at the 4- to 8-cell stage in human embryos and is marked by continuation of early cleavage divisions in the presence of transcriptional inhibitors. Here we demonstrate, using reverse transcriptase-polymerase chain reaction (RT-PCR), the presence of transcripts for two paternal Y chromosomal genes, ZFY and SRY in human preimplantation embryos. ZFY transcripts were detected as early as the pronucleate stage, 20-24 h post-insemination in vitro and at intermediate stages up to the blastocyst stage. SRY transcripts were also detected at 2-cell to blastocyst stages. The expression of SRY and ZFY at these early stages and the faster cleavage rate of male embryos observed in many mammalian species focuses attention on the role of events in sex determination prior to gonad differentiation.
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PMID:Transcription of paternal Y-linked genes in the human zygote as early as the pronucleate stage. 866 58

Because male ovine embryos develop faster than female embryos, the transcription of SRY and ZFY, two genes located on the Y chromosome, was examined in preimplantation stages using the reverse transcriptase polymerase chain reaction (RT-PCR). RNA was extracted from pools of ovine embryos matured and fertilized in vitro then cultured in synthetic oviduct fluid medium and recovered from 24 to 207 hr post-insemination (two-cell up to hatched blastocyst stage). Since primers used to amplify ZFY also amplify the homologue ZFX, located on the X chromosome, transcripts were differentiated by digestion with restriction enzymes. ZFY and ZFX transcripts were present in all stages examined following RT-PCR, whereas transcripts for SRY were undetectable in all investigated stages following either RT nested PCR or Southern analysis. The presence of ZFY transcripts suggests that Y chromosome is transcriptionally active during early ovine preimplantation development. The possible relationship between a faster growth of male embryos and the transcription of Y-linked genes at early stages of development is discussed.
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PMID:Transcription of Y- and X-linked genes in preimplantation ovine embryos. 891 69

We have examined mRNA expression of two genes located on the Y chromosome, the sex-determining region Y gene (SRY) and the linked zinc finger gene (ZFY), using in vitro fertilized-in vitro cultured bovine embryos. Expression of the SRY gene, implicated in sex determination in mammals, has been reported to occur both for a short time at the sex-determining stage of development around the period of the primitive undifferentiated gonad and in the adult testis. In this study, using a sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay, we detected SRY but not ZFY mRNA expression as early as the 4- to 8-cell stage and through to the blastocyst stage in bovine embryos. The expression of SRY at these early stages and the previous observation that in vitro-produced male bovine embryos develop faster in culture than female embryos suggest that sex differences are evident prior to gonadal differentiation and that preimplantation bovine embryos have sexually dimorphic gene expression at least with respect to SRY transcripts.
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PMID:Early transcription of the SRY gene by bovine preimplantation embryos. 929 74

The transition between dependence on maternal transcripts and proteins inherited in the oocyte and embryonic gene expression in the human preimplantation embryo occurs at the four- to eight-cell stage. Recently, studies using reverse transcriptase polymerase chain reaction (RT-PCR) have detected paternal transcripts for the Y-linked genes, ZFY and SRY, and the myotonic dystrophy associated protein kinase gene, DK, as early as the late pronucleate one-cell stage. However, expression at the protein level has not been demonstrated and its function at these early stages is unknown. Using coding sequence polymorphisms to distinguish maternal and paternal transcripts, we have examined the transcription of two ubiquitously expressed genes: X-linked glucose-6-phosphate dehydrogenase (G6PD) and adenosine deaminase (ADA). Both G6PD and ADA are housekeeping genes with TATA-less promoters which, because of their roles in metabolism and ubiquitous expression, may provide a more reliable indication of the timing of activation of the embryonic genome. They also each have biallelic polymorphisms with a high heterozygosity ratio which can be detected by restriction digestion. Couples undergoing in vitro fertilization (IVF) were screened for these polymorphisms. Individual spare oocytes and embryos at different stages of preimplantation development were analyzed by RT-PCR and appropriate restriction digestion in those cases in which the male partner carried a different allele to the female partner. In addition, since only female embryos inherit the paternal allele of X-linked G6PD, cDNA was also analyzed for ZFX/ZFY transcripts to identify the sex of each embryo. One hundred and twenty three individual oocytes and embryos were analyzed by RT-PCR and restriction digestion to detect the paternal transcripts from the polymorphic alleles. Maternal transcripts for G6PD, ADA, and ZFX were detected in all oocytes and embryos and at all stages. Following restriction digestion, paternal G6PD and ZFY transcripts were first detected at the four-cell stage and paternal ADA transcripts in an embryo at the three-cell stage coinciding with the onset of dependency on transcription from the embryonic genome. This approach should be widely applicable to other genes since similar polymorphisms exist in the coding regions of many genes.
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PMID:Paternal transcripts for glucose-6-phosphate dehydrogenase and adenosine deaminase are first detectable in the human preimplantation embryo at the three- to four-cell stage. 936 38

When examining gene expression profiles for the purposes of assessing embryo quality, it is imperative that sex be considered, because many embryonic transcripts have sex-related expression patterns. The objective of this study was to systematically examine eight Y chromosome linked genes (DDX3Y, EIF1AY, HSFY, SRY, TSPY, USP9Y, ZFY, and ZRSR2Y) to characterize their expression in bovine blastocysts and to examine the usefulness of this expression for the purpose of RNA-based embryo sexing. In order to examine the expression of these genes, pools of blastocysts (groups of 10 and 20) as well as single embryos (N = 50) were analyzed with reverse transcriptase polymerase chain reaction (RT-PCR) and reverse transcriptase quantitative PCR (RT-qPCR). Of the 50 single embryos, 32 were concurrently sexed with DNA-based methods. Transcripts of DDX3Y, EIF1AY, TSPY, USP9Y, ZFY and ZRSR2Y were detected in the pooled and single blastocysts, but no transcripts were detected for HSFY or SRY. After performing DNA-based sexing experiments, we concluded that this expression was restricted to the male embryos. The consistency of the expression varied according to the gene as well as the specific primer set. Three genes were expressed in the full set of male embryos, DDX3Y, USP9Y, and ZRSR2Y and therefore represent good candidates for RNA-based sexing methods.
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PMID:A novel approach to sexing bovine blastocysts using male-specific gene expression. 2234 5