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Topic: Spermatocyte

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	DEGS1 - degenerative spermatocyte homolog 1, lipid desaturase (Drosophila)
		DEGS1 is a homologue of DEGS1 (degenerative spermatocyte homolog 1, lipid desaturase (Drosophila)) from Gallus gallus.
		DEGS1 is a homologue of Degs1 (degenerative spermatocyte homolog 1 (Drosophila)) from Mus musculus.
		DEGS1 is a homologue of Degs1 (degenerative spermatocyte homolog 1 (Drosophila)) from Rattus norvegicus.
	www.ihop-net.org /UniPub/iHOP/gg/93954.html (737 words)

	[No title]
		dividing primary spermatocytes (diplotene stage); the metaphase, anaphase, and telophase of the first meiotic division (respectively equatorial arrangement of chromosomes, movement to cell poles, and actual division of the cell) are completed quickly, and are therefore only present briefly.
		leptotene/zygotene primary spermatocytes; in the leptotene stage, there is reorganisation of chromatin, which leads to fusion of homologous chromosomes in the zygotene stage.
		dividing primary spermatocytes; the metaphase, anaphase, and telophase of the first meiotic division (respectively equatorial arrangement of chromosomes, movement to cell poles, and actual division of the cell) are completed quickly, and are therefore only visible briefly.
	www.rivm.nl /fishtoxpat/tesarch3bo.htm (777 words)

	I. Embryology. 3. The Spermatozoön. Gray, Henry. 1918. Anatomy of the Human Body.
		The spermatozoa are developed from the primitive germ cells which have become imbedded in the testes, and the stages of their development are very similar to those of the maturation of the ovum.
		Each primary spermatocyte divides into two secondary spermatocytes, and each secondary spermatocyte into two spermatids or young spermatozoa; from this it will be seen that a primary spermatocyte gives rise to four spermatozoa.
		7) it will be observed that the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the primary oöcyte to two cells, the secondary oöcyte and the first polar body.
	www.bartleby.com /107/4.html (777 words)

	Development of normal mice from metaphase I oocytes fertilized with primary spermatocytes -- Ogura et al. 95 (10): 5611 ... (Site not responding. Last check: 2007-10-29)
		The cell-cycle stages of primary spermatocytes and oocytes were synchronized at the GV (Method A), Met I (Method B), or Met II (Method C) stages.
		Spermatocyte chromosomes (4N) undergo two meiotic divisions in oocytes and participate in the formation of a haploid (N) male pronucleus.
		Both the spermatocyte and oocyte chromosomes are aligned on the Met I spindle of the oocyte, which has been arrested by cytochalasin treatment.
	www.pnas.org /cgi/content/full/95/10/5611 (2860 words)

	Cannonball
		Wild-type function of four Drosophila genes, spermatocyte arrest, cannonball, always early and meiosis I arrest, is required both for cell-cycle progression through the G2/M transition of meiosis I in males and for onset of spermatid differentiation.
		Among the cysts of spermatocytes at the transition phase that were examined by Hoechst stain of live squashes: 38% were at stage B, 27% were at stage C, 21% were in prometaphase and 14% were at metaphase.
		In contrast, in wild-type spermatocytes with chromosomes at the same degree of condensation, the nucleoli have already initiated breakdown and cytoplasmic astral arrays of microtubules are visible.
	www.sdbonline.org /fly/sturtevant/cannonball4.htm (6718 words)

	spermatogenesis
		These divisions begin with the primary spermatocyte which is formed from mitosis, the Sertoli cell then triggers the primary spermatocyte to enters meiosis where it progresses through interphase, DNA synthesis and then the long prophase consisting of leptotene, zygotene, pachytene, diplotene and dictyotene.
		The primary spermatocyte then quickly divides to form a secondary spermatocyte, which does not replicate the DNA and divides to form the round spermatids.
		Find pirmary spermatocytes that are in either zygotene or pachytene and newly formed round spermatids that do not yet have acrosomal granules present.
	www.wisc.edu /ansci_repro/lab/lab8/spermatogenesis/spermatogenesis.html (351 words)

	Spermatocyte - Wikipedia, the free encyclopedia
		A spermatocyte is a male gametocyte which is derived from a spermatogonium.
		Initially, a spermatogonium divides by mitosis into two so-called primary spermatocytes.
		A primary spermatocyte is also diploid, and, in turn, gives place by meiosis to two secondary spermatocytes, which this time are haploid.
	en.wikipedia.org /wiki/Spermatocyte (199 words)

	Lecture 12 Reveiw Quiz
		In the bull, spermatogenesis involves the mitotic divisions of the sequence: Spermatogonium A to I to B and finally a primary spermatocyte.
		Spermiation is the release of spermatozoa from Sertoli cells and the phagocytosis of the residual bodies by the Sertoli cells.
		A reseacher examines a cross section of a rocky mountain sheep testis and observes that in some of the seminiferous tubules are type A spermatogonia, primary spermatocytes and round spermatids with the start of acrosomal granules.
	www.wisc.edu /ansci_repro/lec/quizes/lec_12quiz.htm (573 words)

	Handbook of Andrology
		At the end of the second meiotic division, each secondary spermatocyte has divided into two spermatids so that there are a total of four spermatids that were derived from the primary spermatocyte (Table 1).
		At the end of the first meiotic division, the secondary spermatocytes have 23 double-stranded (containing a pair of daughter chromatids) unpaired chromosomes and are, therefore, haploid (1N).
		After the S-phase (at the beginning of meiosis) the primary spermatocytes have doubled their amount of DNA and, therefore, are 4N.
	www.andrologysociety.com /resources/handbook/ch.6.asp (689 words)

	Surveillance of Different Recombination Defects in Mouse Spermatocytes Yields Distinct Responses despite Elimination at ...
		Earlier-stage spermatocytes present in the mutants are indicated (preleptotene, PL; leptotene, L), as are intermediate (In) and B (Bs) spermatogonia.
		spermatocytes (B) stain positive for H1t, although generally not as brightly as the wild type, and localize XMR to a discrete domain, although in fewer cells than in the wild type.
		Rad51 immunocytology in rat and mouse spermatocytes and oocytes.
	mcb.asm.org /cgi/content/full/25/16/7203 (6384 words)

	Genetic Features of Turner Syndrome (Site not responding. Last check: 2007-10-29)
		Sometimes there may be loss of an X or Y chromosome during meiosis, so that a gamete is formed containing 22 normal autosomes, but without a sex chromosome.
		If the spermatocyte that is missing a sex chromosome fertilizes a normal egg containing a single X, the fetus will have X monosomy (eg.
		These are gametes called spermatocytes, containing 1 copy of each of the 22 autosomes, and a single sex chromosome, either an X or a Y. A sperm cell precursor undergoes meiosis, in which the chromosome pairs are split up, forming gametes containing only a single copy of each chromosome.
	turners.nichd.nih.gov /GenDiagramA.html (109 words)

	Cell interactions in spermatocyte apoptosis
		Hence, they argue, CO generated within the Leydig cells reaches the developing spermatocytes and causes them to undergo Fas-dependent apoptosis, rather than meiosis.
		Germ cells apparently die prior to meiosis, since the Fas ligand protein is induced specifically in diploid and tetraploid cells but is not found at heightened levels in the surviving population of haploid spermatids, and the latter cells do not show nuclear condensation or fragmentation, the usual hallmarks of apoptotic cells.
		The authors suggest that, even in unstressed animals, Leydig cell HO-1 and CO accumulation around germ cells may contribute to a background level of spermatocyte apoptosis in unstressed animals.
	www.eurekalert.org /pub_releases/2002-02/joci-cii020802.php (283 words)

	Meiotic Telomere Distribution and Sertoli Cell Nuclear Architecture Are Altered in Atm- and Atm-p53-Deficient Mice -- ...
		disruption causes a pronounced accumulation of spermatocytes with clustered telomeres.
		(b) Spermatocyte nucleus at zygotene equivalent stage with fragments of SCs is devoid of H1t signals.
		spermatocytes to be endowed with a bouquet topology.
	mcb.asm.org /cgi/content/full/20/20/7773 (5965 words)

	Factors Affecting Meiotic and Developmental Competence of Primary Spermatocyte Nuclei Injected into Mouse Oocytes -- ...
		One pair is presumed to be of spermatocyte origin, the other of the oocyte itself.
		presumed to be of primary spermatocyte or of Met-I spermatocyte
		of injected spermatocyte nuclei and the behavior of spermatocyte
	www.biolreprod.org /cgi/content/full/59/4/871 (4099 words)

	Spermatogenesis - Wikipedia, the free encyclopedia
		Maturation occurs in the epididymis and involves the acquisition of a tail and hence motility.
		Spermatocytogenesis is the male form of gametocytogenesis and results in the formation of spermatocytes possessing half the normal complement of genetic material.
		This division implicates sources of genetic variation, such as random inclusion of either parental chromosomes, and chromosomal crossover, to increase the genetic variability of the gamete.
	en.wikipedia.org /wiki/Spermatogenesis (1437 words)

	Dividing Spermatocytes (Site not responding. Last check: 2007-10-29)
		his picture shows two secondary spermatocytes, the parent cells of sperm.
		These cells have just been born as a result of the first meiotic division of a primary spermatocyte.
		nucleus, mitochondria, major sperm protein, and membranous organelles) to be shuttled into the forming spermatids, and for spermatocyte components no longer needed by the spermatids (e.g.
	www.mcb.arizona.edu /wardlab/buddingvid.html (182 words)

	Stage 1 of cycle (Site not responding. Last check: 2007-10-29)
		They are indeed very young, having recently been produced by the second meiotic division of secondary spermatocytes, at the end of stage 14.
		Some of the nuclei happen to be oriented so the section includes the Golgi complex and beginning of the acrosome vesicle (small, round, pinkish structure at one pole of the nucleus).
		It is just beginning its pachytene phase, which will continue for almost two weeks, during which the chromosome pairs undergo synapsis and then possible crossing over (exchange of DNA sequences).
	www-personal.umich.edu /~akc/CycleSE/01stage-C19L73(50).htm (338 words)

	The Caenorhabditis elegans spe-39 Gene Is Required for Intracellular Membrane Reorganization During Spermatogenesis -- ... (Site not responding. Last check: 2007-10-29)
		C1 is a magnified view of the arrested spermatocytes in C. (D–H) Stages of wild-type spermatogenesis in dpy-11 males.
		After meiosis I, the spermatocyte can remain undivided (E and J) or divide into two secondary spermatocytes (one shown in F and K), either of which can progress to the budding stage.
		(C–E, G, and H) Phenotypes of spe-39(eb9) and (tx12) arrested spermatocytes that are shared by both mutants include naked FBs (C), the improper segregation of fibrous bodies to the residual body (left arrow in D), a large number of small vesicles (v in E), and disorganized perinuclear material (arrows in G).
	www.genetics.org /cgi/content/full/165/1/145 (6489 words)

	Differential polarization microscopy of changes in structure in spermatocyte nuclei (Site not responding. Last check: 2007-10-29)
		Thus, images based on linear dichroism, circular dichroism, and linear and circular differential scattering can be used to detect specific types of structures which may be difficult to observe by conventional methods.
		We have used such 'linear and circular differential imaging' to study the structure of the nucleolus (the site of RNA synthesis) in live primary spermatocytes of Drosophila when they are transcriptionally active or inactive.
		Some inactive nucleoli are bipartite, with two distinct structures visible by differential scattering of both linearly and circularly polarized light.
	www.nature.com /nature/journal/v328/n6129/abs/328452a0.html (330 words)

	Drosophila Centrosomin Protein is Required for Male Meiosis and Assembly of the Flagellar Axoneme -- Li et al. 141 (2): ... (Site not responding. Last check: 2007-10-29)
		The aggregates of three major chromosomes are associated with the nuclear membrane; each spermatocyte has two centrosomes (arrowheads, stained with centrosomin) associated with the cell membrane (not labeled) in addition to high levels of cytoplasmic staining.
		Accumulation of centrosomin in the spermatocyte centrosome is not dependent on the presence of microtubules.
		In wild-type testis, mature spermatocytes have a dense array of cytoplasmic microtubules (A).
	www.jcb.org /cgi/content/full/141/2/455 (6786 words)

	Gazi Tıp Fakültesi - Gazi Medical Journal
		In the 20th study group spermatogonium, spermatocyte I, spermatocyte II were seen in seminiferious tubules (Fig.
		In the control group, spermatogonium spermatocyte I, spermatocyte II were observed but spermatide and spermium could not be differentiated (Fig.
		In the study group spermatogonium, spermatocyte I and II as well as spermatide and mature spermium were observed in the walls of the seminiferous tubules.
	www.med.gazi.edu.tr /gmj/96-1a.html (2990 words)

	Specific Binding of Nuclear Proteins to a Bifunctional Promoter Element Upstream of the H1/AC Box of the ...
		the gene in pachytene primary spermatocytes [7, 8].
		The region of RE and the AC box bound by spermatocyte nuclear proteins in footprint analysis are indicated.
		The last two lanes show binding patterns of nuclear proteins derived from a cell population enriched in pachytene primary spermatocytes and from a cell population enriched in early spermatids.
	www.biolreprod.org /cgi/content/full/68/6/2267 (5185 words)

	A Misexpression Screen Reveals Effects of bag-of-marbles and TGF{beta} Class Signaling on the Drosophila Male Germ-Line ...
		Expression of UAS-GFP at the testes tip is shown in (B) germ cells under control of the nos-gal4 transgene driver, single GSC (large arrow), gonialblast (small arrow), spermatogonia (large arrowheads), spermatocytes (small arrowhead), and in (C) somatic cyst cells (arrows) under control of the ptc-gal4 transgene driver.
		(A) Whole wild-type testes, small early germ cells (arrowhead) at the apical tip, larger-sized spermatocytes (fl arrow) displaced away from the tip, differentiating round spermatids (white arrow) along the coil of the testis, and bundles of elongated spermatids (ST are shown).
		High levels of dpp block the transition from spermatogonia to spermatocyte stage and eventually push the cells into death.
	www.genetics.org /cgi/content/full/167/2/707 (9656 words)

	Oestrogen does not affect the restoration of spermatogenesis in the gonadotrophin-releasing hormone-immunised adult rat ...
		in spermatogonial and spermatocyte populations to 50% and 10%
		spermatocytes were suppressed to 12% of control values.
		of testosterone on pachytene spermatocytes was not altered by
	joe.endocrinology-journals.org /cgi/content/full/185/3/529 (5427 words)

	GENETICALLY MODIFIED SPERM IN FISH
		This implies that later stages of male germ cells, such as postmeiotic spermatocytes and spermatids, may not be sensitive to retroviral infection.
		Hence, the determination of the developmental stage at which male germ cells are competent to receive a foreign gene is of considerable interest.
		If the spermatocyte is competent to accept foreign DNA, we are ready to produce transgenic animals by means of in vitro-cultured spermatids.
	www.isb.vt.edu /articles/apr0401.htm (1122 words)

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