Role of Sex Chromosomes in the Control of Male Germ‐Cell Differentiation<sup>a</sup>

Handel, Mary Ann; Hunt, Patricia A.; Kot, Mary C.; Park, Cynthia; Shannon, M. Frances

doi:10.1111/j.1749-6632.1991.tb27301.x

Cited by 11 publications

(6 citation statements)

References 23 publications

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“…Although we have not completely eliminated the second or third possibilities, we believe our data strongly support the first. Specifically, because the gene for the somatic CstF-64 is on the X chromosome, transcription of that gene is likely inactivated during male meiosis (28). For inactivation of essential X-linked genes, often an intronless retroposon on an autosome is activated during meiosis to replace that function, as is true for phosphoglycerate kinase-1 (27,43), pyruvate dehydrogenase E1␣ subunit (44), and glucose-6-phosphate dehydrogenase (45).…”

Section: Discussionmentioning

confidence: 99%

Two distinct forms of the 64,000 M _r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Wallace

Dass

Ravnik

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

107

158

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Polyadenylation in male germ cells differs from that in somatic cells. Many germ cell mRNAs do not contain the canonical AAUAAA in their 3 ends but are efficiently polyadenylated. To determine whether the 64,000 M r protein of the cleavage stimulation factor (CstF-64) is altered in male germ cells, we examined its expression in mouse testis. In addition to the 64,000 M r form, we found a related Ϸ70,000 M r protein that is abundant in testis, at low levels in brain, and undetectable in all other tissues examined. Expression of the Ϸ70,000 M r CstF-64 was limited to meiotic spermatocytes and postmeiotic spermatids in testis. In contrast, the 64,000 M r form was absent from spermatocytes, suggesting that the testis-specific CstF-64 might control expression of meiosis-specific genes. To determine why the 64,000 M r CstF-64 is not expressed in spermatocytes, we mapped its chromosomal location to the X chromosome in both mouse and human. CstF-64 may, therefore, be absent in spermatocytes because the X chromosome is inactivated during male meiosis. By extension, the testis-specific CstF-64 may be expressed from an autosomal homolog of the X chromosomal gene.Polyadenylation, the process of 3Ј end formation in eukaryotic mRNAs, is required for synthesis, transport, translation, and stability of most mRNAs (1-4). The sequence AAUAAA specifies accurate and efficient addition of poly(A) to the mRNA 3Ј end (5, 6). Substitutions at any position in this sequence diminish polyadenylation in vivo and in vitro (7-9), and 90-95% of sequenced mRNAs have AAUAAA in their 3Ј ends (1, 2). However, many mRNAs expressed in male germ cells do not have AAUAAA (refs. 10-13 and Table 1), but are nevertheless efficiently polyadenylated. Sequences such as UAUAAA, AUUAAA, UACAAA, and GAUAAA might substitute for the normal polyadenylation signal (10, 11), but no experimental evidence support these assertions.One hypothesis to account for the use of non-AAUAAA signals is that a protein involved in polyadenylation is altered in germ cells. A candidate is the 64,000 M r subunit of the cleavage stimulation factor (CstF-64) (14, 15), one of three polypeptides of CstF (16). CstF-64 has been shown to be essential for growth and viability of avian cells (17) and acts by binding to a U-or G͞U-rich region downstream of the cleavage site (18) whereas a 160,000 M r protein of the cleavage and polyadenylation specificity factor binds to the AAUAAA signal (19,20). CstF-64 governs polyadenylation site choice in adenovirus (21) and is involved in the immunoglobin switch from a membrane to secretory form during B-cell maturation (22)(23)(24). CstF also is involved in the cooperation of polyadenylation with splicing (25), and recent results show that it interacts with the C-terminal domain of RNA polymerase II and thus couples polyadenylation with transcription (26).Because of its essential role in somatic cell polyadenylation, we examined CstF-64 expression in male germ cells to test the hypothesis that it might contribute to polyadenylation of non-AA...

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Section: Discussionmentioning

confidence: 99%

Two distinct forms of the 64,000 M _r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Wallace

Dass

Ravnik

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

107

158

View full text Add to dashboard Cite

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“…This reveals striking parallels between male and female germ cell development, despite the fact that these lineages are distinguished by entry of fetal female germ cells into meiosis while fetal male germ cells remain mitotic [6]. Hischer et al [70] described this parallel development of female and male germ cells as follows: ''The final comparison of the female and male gametogenesis shows that the 'gonia stage' of the female germ cells is limited to one proliferation wave only (first part of oogenesis), whereas the 'gonia stage' of the male germ cells consists of a first proliferation wave-comparable to that of oogonia-(first part of prespermatogenesis), a preparation phase to initiate spermatogenesis (second part of prespermatogenesis), and a second proliferation wave with renewal and differentiation of the spermatogonia (third part of prespermatogenesis).''…”

Section: Preferable Terminology For Fetal and Neonatal Male Germ Cellmentioning

confidence: 95%

“…Once specified, these lineages follow dynamic differentiation pathways that are largely sexually dimorphic and include distinguishable stages throughout embryonic, fetal, neonatal, pubertal, and adult development [3][4][5][6][7][8]. In both sexes, these different stages are typically distinguished by distinct terminology for each different cell type within each developing lineage.…”

Section: Introductionmentioning

confidence: 99%

Toward a More Precise and Informative Nomenclature Describing Fetal and Neonatal Male Germ Cells in Rodents1

McCarrey

2013

Biology of Reproduction

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The germ cell lineages are among the best characterized of all cell lineages in mammals. This characterization includes precise nomenclature that distinguishes among numerous, often subtle, changes in function or morphology as development and differentiation of germ cells proceed to form the gametes. In male rodents, there are at least 41 distinct cell types that occur during progression through the male germ cell lineage that gives rise to spermatozoa. However, there is one period during male germ cell development-that which occurs immediately following the primordial germ cell stage and prior to the spermatogonial stage-for which the system of precise and informative cell type terminology is not adequate. Often, male germ cells during this period are referred to simply as "gonocytes." However, this term is inadequate for multiple reasons, and it is suggested here that nomenclature originally proposed in the 1970s by Hilscher et al., which employs the terms M-, T1-, and T2-prospermatogonia, is preferable. In this Minireview, the history, proper utilization, and advantages of this terminology relative to that of the term gonocytes are described.

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“…The significance of high DNA MTase levels in postreplicative germ cells such as leptotene and zygotene spermatocytes is intriguing. It is interesting to note that high levels of DNA MTase appear just prior to X inactivation, which occurs during the pachytene phase of spermatogenesis [53]. X inactivation in male germ cells might involve de novo methylation (as in somatic tissues of females), followed by demethylation at the time of reactivation.…”

Section: Changes In Localization Of Dna Mtase In Isolated Germ Cellsmentioning

confidence: 99%

Regulated Synthesis and Localization of DNA Methyltransferase during Spermatogenesis1

Jue¹,

Bestor²,

Trasler³

1995

Biology of Reproduction

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Differences in the methylation patterns of male and female gamete DNA are likely to be involved in genomic imprinting. However, little is known of the mechanisms that regulate de novo methylation and demethylation during gametogenesis. We report here that the well-characterized M(r) 190,000 form of DNA methyltransferase (the only known form) is present in isolated mitotic, meiotic, and postmeiotic male germ cells, with the exception of meiotic pachytene spermatocytes, where the protein is undetectable by immunoblot analysis and a novel 6.2-kb DNA methyltransferase transcript is present. Whereas replication and methylation are coupled in somatic cells, the presence of DNA methyltransferase in postreplicative male germ cells is consistent with previously observed de novo methylation events in these cells. Immunofluorescence experiments revealed that DNA methyltransferase is localized to the nuclei of male germ cells, with a subset of spermatogonia and postreplicative leptotene/zygotene spermatocytes displaying prominent nuclear foci that are strongly enriched in DNA methyltransferase. The data suggest that down-regulation of DNA methyltransferase expression during the pachytene stage of meiosis utilizes an mechanism that is associated with the production of a larger mRNA, and that de novo methylation in leptotene/zygotene spermatocytes may take place in spatially restricted nuclear domains that are enriched in DNA methyltransferase.

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Role of Sex Chromosomes in the Control of Male Germ‐Cell Differentiation^a

Cited by 11 publications

References 23 publications

Two distinct forms of the 64,000 M _r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Two distinct forms of the 64,000 M _r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Toward a More Precise and Informative Nomenclature Describing Fetal and Neonatal Male Germ Cells in Rodents1

Regulated Synthesis and Localization of DNA Methyltransferase during Spermatogenesis1

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Role of Sex Chromosomes in the Control of Male Germ‐Cell Differentiationa

Cited by 11 publications

References 23 publications

Two distinct forms of the 64,000 M r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Two distinct forms of the 64,000 M r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Toward a More Precise and Informative Nomenclature Describing Fetal and Neonatal Male Germ Cells in Rodents1

Regulated Synthesis and Localization of DNA Methyltransferase during Spermatogenesis1

Contact Info

Product

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Role of Sex Chromosomes in the Control of Male Germ‐Cell Differentiation^a

Two distinct forms of the 64,000 M _r protein of the cleavage stimulation factor are expressed in mouse male germ cells

Two distinct forms of the 64,000 M _r protein of the cleavage stimulation factor are expressed in mouse male germ cells