Different factors influence animal sperm ability to fertilize. Some of them are reviewed here, sperm motility, block to polyspermy, chemioattraction, sperm competition for fertilization. Old and new data are reported, as for example the new notions on sperm motility derived from site directed mutagenesis in rodents, the new notions on the odour receptors in mammalian sperm attraction and new notions on sperm competition, which is variable in different species.
"Mammalian sperm acquire their capability for motility as they traverse the epididymis. Thus, sperm motility is a key factor in allowing us to determine semen quality and fertilizing capacity (Geraci and Giudice, 2005; Petrunkina et al., 2005; Jaffe et al., 2006). Motility in semen is widely controlled by a variety of factors, including concentrations of surrounding metabolites and ions (Ca 2þ , Mg 2þ , etc.), pH, and temperature (Vijayaraghavan et al., 1994; Irvine, 1997; Vera et al., 2003; Myers et al., 2004; Alavi and Cosson, 2005; Pal et al., 2006; Parker and McDaniel, 2006). "
[Show abstract][Hide abstract] ABSTRACT: Seminal plasma, an amorphous material that exists in semen, contains proteins related to sperm forward motility. Employing affinity chromatography with ConA beads and protein ultrafiltration, we isolated and concentrated proteins from heated human seminal plasma. Results of computer-assisted semen analyses (CASA) demonstrated that the forward motility index of bovine spermatozoa from the epididymal caput, incubated with proteins and theophylline, was significantly different from that of spermatozoa incubated with theophylline alone (P < 0.01). The electrophoreses revealed that the protein bands with high molecular weights in the gel of PAGE changed into low molecular weights in the gel of SDS-PAGE. Furthermore, proteins from a separated portion of the PAGE gel were still able to stimulate spermatozoa from the epididymal caput to gain forward motility. Two-dimensional (2D)-gel electrophoresis and mass spectrometry indicated that spots focused on the portion seemed, according to their amino acid sequences, to be like human alpha-1-antitrypsin and zinc-alpha-2-glycoprotein (ZAG) precursors. Western blot analysis showed the presence of these two proteins in seminal plasma. These proteins, related to the forward motility of spermatozoa in human seminal plasma, may play important roles during maturation of spermatozoa, from the epididymis through fertilization in the female reproductive tract.
Molecular Reproduction and Development 09/2007; 74(9):1124-31. DOI:10.1002/mrd.20624 · 2.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Spermatozoa are basic male reproductive cells. An analysis of semen characteristics can provide a reasonable basis upon which
to develop a strategy for maximizing the fertility. Because it is generally accepted that a high percentage of poorly motile
or immotile sperm will adversely affect male fertility, analysis of sperm motility is a central part of the evaluation of
male fertility. To study the motility pattern of small particles is difficult. A new development in medical imaging technology
can now be applied for this purpose. Here, the author used a new medical imaging technology to predict the motility pattern
of sperm. According to this study, it can be seen that the motility of each sperm is horizontal but the motility of all sperms
seems to be directionless. In addition, an interesting observation is that there is a whirling type of sperm motility in case
of erroneous motion.
Sexuality and Disability 08/2007; 25(3):151-154. DOI:10.1007/s11195-007-9041-0 · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Zinc alpha 2-glycoprotein (ZAG) is a protein of interest because of its ability to play many important functions in the human body, including fertilization and lipid mobilization. After the discovery of this molecule, during the last 5 decades, various studies have been documented on its structure and functions, but still, it is considered as a protein with an unknown function. Its expression is regulated by glucocorticoids. Due to its high sequence homology with lipid-mobilizing factor and high expression in cancer cachexia, it is considered as a novel adipokine. On the other hand, structural organization and fold is similar to MHC class I antigen-presenting molecule; hence, ZAG may have a role in the expression of the immune response. The function of ZAG under physiologic and cancerous conditions remains mysterious but is considered as a tumor biomarker for various carcinomas. There are several unrelated functions that are attributed to ZAG, such as RNase activity, regulation of melanin production, hindering tumor proliferation, and transport of nephritic by-products. This article deals with the discussion of the major aspects of ZAG from its gene structure to function and metabolism.
Molecular Cancer Research 07/2008; 6(6):892-906. DOI:10.1158/1541-7786.MCR-07-2195 · 4.38 Impact Factor
Note: This list is based on the publications in our database and might not be exhaustive.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.