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Comment |
Isolation and expression of the human gametocyte-specific factor 1 gene (GTSF1) in fetal ovary, oocytes, and preimplantation embryos. Huntriss J et al. (2016) Gametocyte-specific factor 1 has been shown in other species to be required for the silencing of retrotransposons via the Piwi-interacting RNA (piRNA) pathway. In this study, we aimed to isolate and assess expression of transcripts of the gametocyte-specific factor 1 (GTSF1) gene in the human female germline and in preimplantation embryos. Complementary DNA (cDNA) libraries from human fetal ovaries and testes, human oocytes and preimplantation embryos and ovarian follicles isolated from an adult ovarian cortex biopsy were used to as templates for PCR, cloning and sequencing, and real time PCR experiments of GTSF1 expression. GTSF1 cDNA clones that covered the entire coding region were isolated from human oocytes and preimplantation embryos. GTSF1 mRNA expression was detected in archived cDNAs from staged human ovarian follicles, germinal vesicle (GV) stage oocytes, metaphase II oocytes, and morula and blastocyst stage preimplantation embryos. Within the adult female germline, expression was highest in GV oocytes. GTSF1 mRNA expression was also assessed in human fetal ovary and was observed to increase during gestation, from 8 to 21 weeks, during which time oogonia enter meiosis and primordial follicle formation first occurs. In human fetal testis, GTSF1 expression also increased from 8 to 19 weeks. To our knowledge, this report is the first to describe the expression of the human GTSF1 gene in human gametes and preimplantation embryos.//////////////////
Expression and localization of the novel and highly conserved gametocyte-specific factor 1 during oogenesis and spermatogenesis. Krotz SP et al. OBJECTIVE: To determine the onset of gametocyte-specific factor 1 (Gtsf1) expression in embryogenesis and its relation to Nobox; and to determine its localization during gonadal development and gametocyte maturation. DESIGN: Developmental animal study. SETTING: University reproductive biology laboratory. ANIMAL(S): Mice ranging in age from embryonic day 12.5 to 8 weeks. INTERVENTION(S): Polymerase chain reaction and quantitative polymerase chain reaction were performed to determine the onset of and relative messenger RNA expression. Western blot was performed to confirm protein expression and antibody specificity. In situ hybridization and immunohistochemistry were used determine localization of expression. MAIN OUTCOME MEASURE(S): Gtsf1 messenger RNA expression levels during embryogenesis through adulthood in wild-type mice and in newborn Nobox knockout mice; GTSF1 expression and localization in postnatal mice. RESULT(S): Gtsf1 functions downstream of Nobox and is highly expressed in embryonic male and female gonads, localizing to germ cells throughout development. GTSF1 expression is confined to the cytoplasm in all stages of postnatal oocyte maturation and to prespermatogonia during early postnatal testicular development. CONCLUSION(S): The expression pattern of Gtsf1 and its high conservation suggests that it may play an important role in germ cell development. Further characterization of Gtsf1 may elucidate mechanisms involved in premature ovarian failure.
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Mutations |
2 mutations
Species: D. melanogaster
Mutation name: None
type: null mutation
fertility: infertile - ovarian defect
Comment: DmGTSF1 is necessary for Piwi-piRISC-mediated transcriptional transposon silencing in the Drosophila ovary. Ohtani H 2013 et al.
The Piwi-piRNA (PIWI-interacting RNA) complex (Piwi-piRISC) in Drosophila ovarian somatic cells represses transposons transcriptionally to maintain genome integrity; however, the underlying mechanisms remain obscure. Here, we reveal that DmGTSF1, a Drosophila homolog of gametocyte-specific factor 1 (GTSF1) (which is required for transposon silencing in mouse testes), is necessary for Piwi-piRISC to repress target transposons and neighboring genes. DmGTSF1 depletion affected neither piRNA biogenesis nor nuclear import of Piwi-piRISC. DmGTSF1 mutations caused derepression of transposons and loss of ovary follicle layers, resulting in female infertility. We suggest that DmGTSF1, a nuclear Piwi interactor, is an integral factor in Piwi-piRISC-mediated transcriptional silencing.
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Species: mouse
Mutation name:
type: null mutation
fertility: None
Comment: Gtsf1/Cue110, a gene encoding a protein with two copies of a CHHC Zn-finger motif, is involved in spermatogenesis and retrotransposon suppression in murine testes. Yoshimura T et al. (2009) We recently reported that the Gtsf1/Cue110 gene, a member of the evolutionarily conserved UPF0224 family, is expressed predominantly in male germ cells, and that the GTSF1/CUE110 protein is localized to the cytoplasm of these cells in the adult testis. Here, to analyze the roles of the Gtsf1/Cue110 gene in spermatogenesis, we produced Gtsf1/Cue110-null mice by gene targeting. The Gtsf1/Cue110-null mice grew normally and appeared healthy; however, the males were sterile due to massive apoptotic death of their germ cells after postnatal day 14. In contrast, the null females were fertile. Detailed analyses revealed that the Gtsf1/Cue110-null male meiocytes ceased meiotic progression before the zygotene stage. Thus, the Gtsf1/Cue110 gene is essential for spermatogenesis beyond the early meiotic phase. Furthermore, the loss of the Gtsf1/Cue110 gene caused increased transcription of the long interspersed nucleotide element (Line-1) and the intracisternal A-particle (IAP) retrotransposons, accompanied by demethylation of their promoter regions. These observations indicate that Gtsf1/Cue110 is required for spermatogenesis and involved in retrotransposon suppression in male germ cells.//////////////////
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