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The Zebrafish in Toxicology/Spermatogenesis – Wikibooks, open books for an open world

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Regular Histology[edit]

spermatogenesis[edit]

cysts with successive phases of spermatogenesis in a seminiferous tubule


H&E Putt’s carbol fuchsin

as a marker of spermatogenic maturation
[Berg-JW. Differential staining of spermatozoa in sections of testis. Am.J.Clin.Pathol.23:513-515;1953.]
besides Three and 4: PCNA immunostaining for mitotic exercise

1. spermatogonium A (SgA) [arrows]: giant single cell, with a big hypochromatic nucleus;
early spermatogenic phases don’t stain with Putt’s carbol fuchsin. SgA divides mitotically to resume itself and to provide:

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2. early spermatogonium B (eSgB) [arrows]: morphologically vague from SgA, seems in clusters of 2-Four cells.
Word a single Sertoli cell [red arrows], that are solely often noticed; alternatively, Sertoli cells are distinguished after publicity to androgen or anti-androgen.

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3. early spermatogonium B (eSgB) [arrows in left image]: morphologically vague from SgA, seems in clusters of 2-Four cells;
there’s reasonable mitotic exercise in spermatogonium B, as indicated by PCNA immunostaining [arrows in right image]; in distinction, there’s solely very mild PCNA immunostaining within the single spermatogonium A cell [red arrows in right image].
Early SgB divide mitotically to provide:

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4. late spermatogonium B: smaller than early SgB, clusters >Four cells [arrows in left image]; there’s excessive mitotic exercise, as indicated by the sturdy PCNA immunoreactivity [arrows in right image].

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5. late spermatogonium B: clusters >Four cells [arrows]. Late SgB divides to yield smaller major spermatocytes.
Main spermatocytes bear meiosis, which consists of DNA duplication (yielding tetraploid cells: two copies of every chromosome, every copy consisting of two sister chromatids), genetic recombination, and two maturation divisions. The product of the primary maturation division are secundary spermatocytes (diploid: one copy of every pair of chromosomes, consisting of two sister chromatids), the second maturation division yields spermatids (haploid).
The primary maturation division takes days, and subsequently the successive phases of this division can simply be discerned:

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6. spermatocyte, leptotene stage of meiotic prophase (“threadlike” look of chromosomes).

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7. spermatocyte, leptotene stage of meiotic prophase, progressing to the zygotene stage;
Word that there’s staining with Putt’s carbol fuchsin from this stage on, though nonetheless faint right here.

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8. spermatocyte, zygotene stage of meiotic prophase (“bouquet” configuration of chromosomes)

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9. spermatocyte, zygotene stage of meiotic prophase (“umbrella” configuration of chromosomes).

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10. pachytene major spermatocytes; on this stage, there’s longitudinal contraction of the chromosomes, and the chromatin strands have a rough look.

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11. dividing major spermatocytes (diplotene stage); the metaphase, anaphase, and telophase of the primary meiotic division (respectively equatorial association of chromosomes, motion to cell poles, and precise division of the cell) are accomplished rapidly, and are subsequently solely current briefly. The daughter cells of the primary meiotic division are generally known as secundary spermatocytes (diploid). The second meiotic division can be accomplished rapidly, and subsequently secundary spermocytes are neither simply discernible. The ensuing cells of the second meiotic division are:

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12. spermatids (haploid).

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13. spermatids.

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14. mature spermatozoa are launched from open spermatocysts into the lumen of the tubules (spermiation).

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