Disease relevance of Sperm Head

• In contrast, sperm head AChE-R staining was conspicuously reduced in samples from human couples for whom the cause of infertility could not be determined, similar to the pattern found in transgenic mice [1].
• The response of mouse testis stem cells to hyperthermia and combined hyperthermia-radiation treatments was assayed by spermatogenic colony regrowth, sperm head counts, testis weight loss, and fertility [2].
• The ability of intraperitoneally administered cadmium chloride (0.42-6.75 mg/kg) to induce genotoxic damage in somatic and germ cells of mice was evaluated using chromosomal aberrations, sister-chromatid exchanges (SCE), micronuclei and sperm-head abnormalities as end-points [3].
• These results suggest that male infertility of the Tnp2(-/-) mice is a result of sperm head abnormalities and reduced sperm motility [4].
• Testicular weights, sonication-resistant sperm head counts, and quantitative testicular histology revealed protection of the spermatogenic epithelium from PCZ toxicity by gonadal steroid hormones when compared with the C controls [5].

High impact information on Sperm Head

• The mutagenic and clastogenic (chromosome breaking) effects of the flame retardant Tris(2,3-dibromopropyl) phosphate (Tris-BP) were investigated in two mammalian in vivo assays, the bone marrow micronucleus test and the abnormal sperm head assay [6].
• In the micronucleus test, Tris-BP was a weak clastogen, whereas in the abnormal sperm head assay, Tris-BP was observed to be strongly mutagenic [6].
• In some patients with severely amorphous sperm heads, protein 4.1 had an abnormal sub-cellular localisation (tail instead of head) and appeared as high-molecular-weight isoforms, especially a 135 kDa species instead of the 82 kDa isoform seen in fertile sperm [7].
• Immunodepletion of gamma-tubulin and associated molecules from the egg extract before sperm head incubation prevents the change in microtubule-organizing activity of the sperm heads [8].
• The cytoskeletal calyx structure surrounding part of the nucleus of the mammalian sperm head contains two major kinds of basic proteins, i.e., the approximately 60-kD calicin and a group of very basic (IEP > pH 10) polypeptides ranging in size from approximately 58 to approximately 100 kD ("multiple band proteins," MBPs) [9].

Chemical compound and disease context of Sperm Head

• In present studies the development of chromosomal aberrations, micronuclei in bone marrow cells and sperm head abnormalities were used as mutagenic bioassay in Swiss albino mice treated with cisplatin alone or ascorbic plus cisplatin [10].
• Antimony trioxide (Sb2O3), in aqueous suspension, was administered by gavaging to mice and monitored for chromosomal aberrations in bone marrow and sperm head abnormalities in germ cells [11].

Biological context of Sperm Head

• ATP concentrations within the sperm heads declined in response to Nigericin, pH 9.0 seawater, or A23187, and its decrease also required the presence of extracellular Ca2+ [12].
• During spermatogenesis, DNA in the sperm head becomes more tightly condensed as histones are replaced by protamine-like molecules [13].
• These data demonstrate that Gi protein alpha-subunits are present in the acrosomal region of mammalian sperm, consistent with their postulated role in regulating ZP3-mediated acrosomal exocytosis, and that PT-insensitive Gz alpha is found in a region of the sperm head distinct from that of the Gi alpha subunits [14].
• CONTEXT: SHBG gene expression in human testis results in an SHBG isoform that accumulates in the sperm head [15].
• Blocking of thiols and PTP activity with N-ethylmaleimide led to increased tyrosine phosphorylation of protamine in caput sperm heads [16].

Anatomical context of Sperm Head

• When ejaculated mouse spermatozoa were embedded in a plasminogen-containing insoluble protein substrate, a zone of proteolysis developed progressively, centered around the sperm head region [17].
• Expression of mouse zonadhesin mRNA is evident only within the testis, and the protein is found exclusively on the apical region of the sperm head [18].
• In the elongating spermatid, delta-tubulin associated with the manchette, a specialised microtubule system present during reshaping of the sperm head [19].
• Creatine kinase from sperm heads was localized to the mitochondrion by an antibody raised against mouse muscle creatine kinase [20].
• When motile sperm were cocultured with purified polymorphonuclear leukocytes (PMN) in the presence of C-fixing immune sera, the binding of sperm heads to the PMN resulted in the formation of sperm rosettes, whereas non C-fixing or control sera had no such effect [21].

Associations of Sperm Head with chemical compounds

• This activity was labile to freezing and stimulated by 0.04% Triton X-100, and thus differed from that of sperm heads [22].
• Treatment of caput or cauda epididymal rat sperm with a low concentration (0.05%) of the cationic detergent cetyltrimethylammonium bromide and 30 mM 2-mercaptoethanol solubilized most of the sperm structures except for the sperm head and the outer dense fiber-connecting piece complex [23].
• The elevation of cyclic AMP concentrations in flagella-less sea urchin sperm heads [12].
• A model is proposed in which phospholipid scrambling induces the formation of an apical membrane raft in the sperm head surface that enables albumin mediated efflux of cholesterol [24].
• Addition of albumin caused cholesterol efflux, but only in bicarbonate-responding cells that exhibited virtually no filipin labeling in the sperm head area [24].

Gene context of Sperm Head

• During sperm head differentiation, both Imp-alpha1 and -alpha3 are nuclear [25].
• In contrast, only T-ACTIN-2 was present in sperm heads and tails [26].
• Immunocytochemical data indicated that PDE1A, a variant of PDE1, is localized on the equatorial segment of the sperm head as well as on the mid and principal pieces of the flagellum, and that PDE3A is found on the postacrosomal segment of the sperm head [27].
• Boar spermadhesins AQN-1, AQN-3 and AWN form a recently described protein family, synthesized by the sexual accessory glands, and become associated with the sperm head upon ejaculation [28].
• Ube2b(-/-) mice were shown to present male infertility and their sperm head shape anomalies suggested that Ube2b may be involved in the replacement of nuclear proteins during spermatid chromatin condensation [29].

Analytical, diagnostic and therapeutic context of Sperm Head

• Indirect immunofluorescence using an antiserum directed against a peptide region present in Gz alpha, a PT-insensitive G protein, demonstrates positive immunoreactivity in the postacrosomal/lateral face region of the mouse sperm head [14].
• Immunofluorescence microscopy localized sperm head PLCzeta to a post-acrosomal region that becomes rapidly exposed to the ooplasm following gamete fusion [30].
• Western blot and immunocytochemical analyses demonstrated that epididymal maturation in vivo is associated with a progressive loss of phosphotyrosine residues from the sperm head [31].
• The only positive result in the sperm-head abnormality test was obtained for the dose of 120 mg/kg/day of sodium nitrite both at 11 and 17 days after treatment [32].
• Immunocytochemistry experiments demonstrated a punctuated staining pattern (with strong, intermediate, or weak H2B staining intensity) throughout the sperm head [33].

References