Mammalian Male Gametogenesis: Growth, Differentiation and Maturation of Germ Cells

Nishimune, Yoshitake; Okabe, Masaru

doi:10.1111/j.1440-169x.1993.00479.x

Cited by 16 publications

(6 citation statements)

References 63 publications

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“…Second, recent data indicate that the c-kit receptor and its ligand Stem Cell Factor (SCF), play a role in the differentiation of A spermatogonia (review Nishimune & Okabe 1993). Koshimizu et al (1991) and Tajima et al (1991) studied the effects of mutations in the dominant white-spotting (W) and Steel (Sl) loci on the differentiation of mouse testicular germ cells using the experimental cryptorchidism and surgical reversal model, described above.…”

Section: Regulation Of the Differentiation Of Undifferentiated Spermamentioning

confidence: 99%

Stem Cells in the Testis

1998

Int J Experimental Path

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Section: Regulation Of the Differentiation Of Undifferentiated Spermamentioning

confidence: 99%

Stem Cells in the Testis

1998

Int J Experimental Path

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“…The postnatal phase can be divided into three main stages: 1) mitotic proliferation of spermatogonial stem cells and premeiotic differentiation of spermatogonia cells to diploid primary spermatocytes; 2) meiotic differentiation of primary spermatocytes to haploid early round spermatids via two successive divisions-the reductional division, in which homologous chromosomes are separated into two haploid secondary spermatocytes (each chromosome consists of two chromatids), and an equational division in which the two chromatids of each chromosome are separated into two haploid round spermatids; and 3) spermiogenesis, a cellular and nuclear reorganization process that turns spermatids into spermatozoa [3]. This latter stage consists of intensive condensation of the chromatin due to replacement of histones by transition proteins and later by protamines [4][5][6][7], a substantial reduction in the cell's volume due to severance of large cytoplasmic fragments, the residual bodies, and formation of a compact head and a long tail.…”

Section: Introductionmentioning

confidence: 99%

Developmental Schedule of the Postnatal Rat Testis Determined by Flow Cytometry1

Malkov

Fisher

Don

1998

Biology of Reproduction

141

138

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Analysis of the biochemical events and the genes expressed at various postnatal developmental stages in the testis of mammals is of great importance for understanding spermatogenesis in general and meiosis in particular. A prerequisite for such an analysis is the characterization of a detailed developmental schedule of the postnatal testis. In this study we used four-parameter flow cytometry analysis to determine a detailed testicular developmental schedule in rats as compared to mice. A dot plot of forward-scatter/side-scatter of testicular cell suspensions from mature animals revealed 7 distinct subpopulations within the testis. These, when analyzed by fluorescence parameters, were divided into 4 levels of fluorescence: cells containing 4d DNA, 2d DNA, and 2 levels of haploid cells. Observing the acquisition pattern of these subpopulations during postnatal development, we were able to suggest the following developmental schedule for the rat. At postnatal Days 6-7, the testis contains somatic cells and spermatogonia cells only. By Days 13-14, leptotene spermatocytes appear; by Days 17-18, zygotene spermatocytes are present; by Days 19-20 and Days 22-23, early and late pachytene spermatocytes, respectively, are seen. Haploid round spermatids first appear at Days 24-25 and elongating spermatids by Days 30-31; by Day 36, elongated spermatozoa can be found.

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“…H1T is the first variant to be expressed in meiotic spermatocytes, the presence in later germ cell stage up to elongated spermatids seems to be species-specific 80 . The dormant PrFs are arrested in meiosis I 83 and primary spermatocytes are in prophase of meiosis I 84 . It could be possible that H1T fulfils a specific function during this cell division phase, for example, on chromatin structure.…”

Section: Discussionmentioning

confidence: 99%

Signalling pathways and mechanistic cues highlighted by transcriptomic analysis of primordial, primary, and secondary ovarian follicles in domestic cat

Kehoe

Jewgenow

Johnston

et al. 2021

Sci Rep

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In vitro growth (IVG) of dormant primordial ovarian follicles aims to produce mature competent oocytes for assisted reproduction. Success is dependent on optimal in vitro conditions complemented with an understanding of oocyte and ovarian follicle development in vivo. Complete IVG has not been achieved in any other mammalian species besides mice. Furthermore, ovarian folliculogenesis remains sparsely understood overall. Here, gene expression patterns were characterised by RNA-sequencing in primordial (PrF), primary (PF), and secondary (SF) ovarian follicles from Felis catus (domestic cat) ovaries. Two major transitions were investigated: PrF-PF and PF-SF. Transcriptional analysis revealed a higher proportion in gene expression changes during the PrF-PF transition. Key influencing factors during this transition included the interaction between the extracellular matrix (ECM) and matrix metalloproteinase (MMPs) along with nuclear components such as, histone HIST1H1T (H1.6). Conserved signalling factors and expression patterns previously described during mammalian ovarian folliculogenesis were observed. Species-specific features during domestic cat ovarian folliculogenesis were also found. The signalling pathway terms “PI3K-Akt”, “transforming growth factor-β receptor”, “ErbB”, and “HIF-1” from the functional annotation analysis were studied. Some results highlighted mechanistic cues potentially involved in PrF development in the domestic cat. Overall, this study provides an insight into regulatory factors and pathways during preantral ovarian folliculogenesis in domestic cat.

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Mammalian Male Gametogenesis: Growth, Differentiation and Maturation of Germ Cells

Cited by 16 publications

References 63 publications

Stem Cells in the Testis

Stem Cells in the Testis

Developmental Schedule of the Postnatal Rat Testis Determined by Flow Cytometry1

Signalling pathways and mechanistic cues highlighted by transcriptomic analysis of primordial, primary, and secondary ovarian follicles in domestic cat

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