Prospects for spermatogenesis in vitro

Parks, John E.; Lee, D.R; Huang, Stephanie; Kaproth, M.

doi:10.1016/s0093-691x(02)01275-x

Cited by 59 publications

(51 citation statements)

References 55 publications

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“…Even more important is the hope of providing a treatment to many infertile individuals. Cocultures of germ cells with Sertoli cells aid a limited number of cells to undergo meiosis and become round spermatids (Parks et al 2003). The latter can be directly injected into oocytes to result in viable embryos and live offspring (Kimura & Yanagimachi 1995, Parks et al 2003.…”

Section: From Embryonic Stem (Es) Cells To Gametes In Vitromentioning

confidence: 99%

“…Cocultures of germ cells with Sertoli cells aid a limited number of cells to undergo meiosis and become round spermatids (Parks et al 2003). The latter can be directly injected into oocytes to result in viable embryos and live offspring (Kimura & Yanagimachi 1995, Parks et al 2003. However, a critical requirement for successful in vitro spermatogenesis is maintaining germcell viability in vitro for long periods of time, and this implies greater limitations on initiation of spermatogenesis from PGCs or GSCs.…”

Section: From Embryonic Stem (Es) Cells To Gametes In Vitromentioning

confidence: 99%

“…The use of PGCs and GSCs in transplantation studies to restore fertility has been initiated with varied degrees of success (Parks et al 2003, Nayernia et al 2004, leading scientists to push boundaries even further by using ES cells as the starting point for germ cell differentiation. Embryoid bodies (EBs), established from ES cells, consist of tissue lineages typical of the early embryo.…”

Section: From Embryonic Stem (Es) Cells To Gametes In Vitromentioning

confidence: 99%

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In vivo and in vitro differentiation of male germ cells in the mouse

Lacham-Kaplan¹

2004

Reproduction

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Primordial germ cells appear in the embryo at about day 7 after coitum. They proliferate and migrate towards the genital ridge. Once there, they undergo differentiation into germ stem cells, known as 'A spermatogonia'. These cells are the foundation of spermatogenesis. A spermatogonia commit to spermatogenesis, stay undifferentiated or degenerate. The differentiation of primordial germ cells to migratory, postmigratory and germ stem cells is dependent on gene expression and cellular interactions. Some of the genes that play a crucial role in germ cell differentiation are Steel, c-Kit, VASA, DAZL, fragilis, miwi, mili, mil1 and mil2. Their expression is stage specific, therefore allowing solid identification of germ cells at different developmental phases. In addition to the expression of these genes, other markers associated with germ cell development are nonspecific alkaline phosphatase activity, the stage specific embryonic antigen, the transcription factor Oct3/4 and b1-and a6-integrins. Commitment of cells to primordial germ cells and to A spermatogonia is also dependent on induction by the bone morphogenetic protein (BMP)-4. With this knowledge, researchers were able to isolate germ stem cells from embryonic stem cell-derived embryoid bodies, and drive these into gametes either in vivo or in vitro. Although no viable embryos were obtained from these gametes, the prospects are that this goal is not too far from being accomplished.

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Section: From Embryonic Stem (Es) Cells To Gametes In Vitromentioning

confidence: 99%

Section: From Embryonic Stem (Es) Cells To Gametes In Vitromentioning

confidence: 99%

Section: From Embryonic Stem (Es) Cells To Gametes In Vitromentioning

confidence: 99%

See 1 more Smart Citation

In vivo and in vitro differentiation of male germ cells in the mouse

Lacham-Kaplan¹

2004

Reproduction

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“…Accurate assessment of testis morphology, sperm composition and the changes taking place in the male gonads is crucial in humans and other species, since this determines their future reproductive ability and enables them to be sperm donors in facilitated reproduction. There is plenty of information available concerning human [4][5][6], bull [7][8][9], boar [10] and stallion [11] germinal epithelium development. Gonad development takes place during the prenatal period.…”

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confidence: 99%

Morphological Features of The Seminiferous Epithelium in Cat (<i>Felis catus</i>, L. 1758) Testes

Siemieniuch

Wocławek-Potocka

2007

Journal of Reproduction and Development

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Abstract. The aim of the present study was to assess the changes in the germinal epithelium in cats of different ages. Routine histological staining was applied to perform morphological and stereological examinations. The animals were divided into five groups according to age: under 8 months (n=28), 8-12 months (n=30), 12-36 months (n=33), 3-6 years (n=14) and older than 6 years (n=13). The appearance of the gonads of the males in the first group varied the most. The seminiferous tubules of the youngest cats consisted of a monolayer of supporting cells and a few spermatogonia. No tubular lumina were present, and the diameters of the seminiferous tubules reached 132.5 µm. We noted the typical arrangement of gametogenic cells with a tubule diameter of 191.83 µm in the second group.We observed multilayer germinal epithelia with the most significant production of gametes and a seminiferous tubule diameter of 202.61 µm in the third group. The diameters of the seminiferous tubules of the forth and fifth groups were 193.38 µm and 191.84 µm, respectively. The obtained data revealed that the most intensive morphological diversification of the seminiferous epithelium in cats occurs at about 7-8 months of age. The diameters of seminiferous tubules were highest in the third group of cats, and the activity of spermatogenesis of this group, expressed as the number of sperm per 10 mm 2 , was also the most distinctive. The spermatogenesis process was most evident in cats between 12 and 36 months of age, which was also when the sperm concentration was highest per estimated surface. Key words: Cat, Seminiferous epithelium, Spermatogenesis, Testis development (J. Reprod. Dev. 53: [1125][1126][1127][1128][1129][1130] 2007) he current description of postnatal development of seminiferous tubules in the cat is rather poor and mainly concerns morphological changes in the gonads of male felines younger than 12 months [1]. However, histological examination of older cats has revealed the degenerative changes in their testes, but only by taking into account the appearance of the connective tissue [2]. In human andrology, the stereological method has been used to assess the number of different cells in the epithelium germinativum [3]. In human testes, the numbers of spermatogonia, primary and secondary spermatocytes and spermatids and spermatozoa are usually examined after hematoxylin/eosin staining [3]. Accurate assessment of testis morphology, sperm composition and the changes taking place in the male gonads is crucial in humans and other species, since this determines their future reproductive ability and enables them to be sperm donors in facilitated reproduction. There is plenty of information available concerning

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“…1 Investigators have been successful in recreating this process in some species of fish; however, this whole process has never been reproduced in vitro in mammals. 2,3 In a recent issue of Nature, Sato and colleagues 4 attempted to produce functional sperm in vitro with cultured neonatal mouse tissue. Using two different transgenic mouse lines that incorporated a green fluorescent protein (GFP) marker, the researchers could follow the relative expression of GFP to define the presence of meiosis and haploid cells.…”

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confidence: 99%