Publication: Spermatogenesis and chromatin condensation in male germ cells of sea cucumber Holothuria leucospilota (Clark, 1920)
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Issued Date
2008
Resource Type
File Type
application/pdf
ISSN
408166
Other identifier(s)
2-s2.0-42049092082
Rights Holder(s)
มหาวิทยาลัยศรีนครินทรวิโรฒ
Bibliographic Citation
Tissue and Cell. Vol 40, No.3 (2008), p.167-175
Suggested Citation
Thongkukiatkul A., Jungudomjaroen S., Ratanapahira C. Spermatogenesis and chromatin condensation in male germ cells of sea cucumber Holothuria leucospilota (Clark, 1920). Tissue and Cell. Vol 40, No.3 (2008), p.167-175. doi:10.1016/j.tice.2007.10.001 Retrieved from: https://hdl.handle.net/20.500.14740/4202
Abstract
Male germ cells in the testis of Holothuria leucospilota can be divided into 12 stages based on ultrastructure and patterns of chromatin condensation. The spermatogonium (Sg) is a spherical-shaped cell with a diameter of about 6.5-7 μm. Its nucleus mostly contains euchromatin and small blocks of heterochromatin scattered throughout the nucleus. The nucleolus is prominent. Primary spermatocytes are divided into six stages, i.e., leptotene (LSc), zygotene (ZSc), pachytene (PSc), diplotene (DSc), diakinesis (DiSc) and metaphase (MSc). The early cells are round while in DiSc and in MSc cells are oval in shape. From LSc to MSc, the sizes of cells range from 3.5 to 4 μm. LSc contains large blocks of heterochromatin as a result of increasingly condensed 17 nm fibers. In ZSc, the nucleus contains prominent synaptonemal complexes but a nucleolus is absent. In PSc, heterochromatin blocks are tightly packed together by 26 nm fibers and appeared as large patches in DSc. Heterochromatin patches were enlarged to form chromosomes in DiSc and MSc and then the chromosome are moved to be aligned along equatorial region. The secondary spermatocyte (SSc) is an oval cell about 4.5-5.5 μm. Their nuclei contain large clumps of heterochromatin along the nuclear envelope and in the center nuclear region. Spermatids are divided into two stages, i.e., early spermatid (ESt) and late spermatid (LSt). The nuclei decrease in size by a half and become spherical; thus the chromatin fibers condensed into 20 nm and are closely packed together leaving only small spaces in LSt. The spermatozoa (Sz), with chromatin tightly packed in the spherical nucleus with a diameter of 2 μm and a small acrosome situated at the anterior of the nucleus. The tail consists of a pair of centrioles lying perpendicular to each other and surrounded by a mitochondrial ring, and an axonemal complex, surrounded by a plasma membrane. © 2007 Elsevier Ltd. All rights reserved.
Subject(s)
Acrosome
Animal cell
Article
Axoneme
Cell membrane
Cell nucleus
Cell shape
Cell size
Cell ultrastructure
Centriole
Chromatin condensation
Euchromatin
Germ cell
Heterochromatin
Holothuria
Male
Metaphase
Mitochondrion
Nonhuman
Nucleolus
Pachytene
Scanning electron microscopy
Sea cucumber
Spermatid
Spermatocyte
Spermatogenesis
Spermatogonium
Synaptonemal complex
Testis cell
Transmission electron microscopy
Holothuria leucospilota
Holothuroidea
Animal cell
Article
Axoneme
Cell membrane
Cell nucleus
Cell shape
Cell size
Cell ultrastructure
Centriole
Chromatin condensation
Euchromatin
Germ cell
Heterochromatin
Holothuria
Male
Metaphase
Mitochondrion
Nonhuman
Nucleolus
Pachytene
Scanning electron microscopy
Sea cucumber
Spermatid
Spermatocyte
Spermatogenesis
Spermatogonium
Synaptonemal complex
Testis cell
Transmission electron microscopy
Holothuria leucospilota
Holothuroidea