نتایج جستجو برای: sperm tail
تعداد نتایج: 87689 فیلتر نتایج به سال:
Ann. Entomol. Soc. Am. 81(2): 292-300 (1988) ABSTRACT We have examined the ultrastructure of post meiotic eupyrene sperm maturation in testes of prepupae, pupae, and adult Heliothis virescens (F.) males. Emphasis was placed on the structures present in the elongating sperm tail. In each young spermatid, each cell has a nucleus, acrosome derivative, and numerous mitochondria in a large volume of...
Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calc...
Background One kind of sperm abnormality that leads to men infertility is short flagella sperms. In this defect, fibrous sheath and axoneme are disorganized, the sperms tail is short, the numbers of sperms in the semen fluid reduce and the sperms are immotile. There are also other kinds of oligoasthenoteratozospermia (OAT) disorder that causes infertility in men. A kinas anchoring protein 3 (AK...
Sperm morphology is unique among the known cells and 3 major parts can be immediately distinguished: head, midpiece and tail. Normal sperm exhibit an oval-shaped head with a regular outline and a cap (acrosome) covering more than one-third of the head surface. The midpiece is slender, less than one third of the width of the head, straight and regular in outline. The tail is slender, uncoiled an...
Abstract Reproductive success depends on efficient sperm movement driven by axonemal dynein-mediated microtubule sliding. Models predict sliding at the base of tail – centriole but such has never been observed. Centrioles are ancient organelles with a conserved architecture; their rigidity is thought to restrict Here, we show that, in mammalian sperm, atypical distal (DC) and its surrounding pe...
In vitro induced apoptosis by dexamethazone treating of ram spermatozoa provoked the phospatidylserine exposure which is mainly localized on sperm tail region of plasma membrane and is correlated negatively with the sperm motility and survival rate.
Objectives: 1. To investigate the incidence, isotypes and location of antisperm antibodies (ASA) on the sperm surface in an infertile population. 2. To study the influence of isotypes, location of ASA on the sperm surface on fertilization, cleavage rates of embryos and pregnancy rate. Methods: A prospective analytical study was carried out on infertile couples who underwent Assisted Reproductiv...
This study was designed to compare the performance of the kits Diff-Quick, Hemacolor and Spermac for staining the spermatozoa of rainbow trout. Automated sperm morphology analysis (ASMA) was performed using two image analysis programs to determine the sperm measurements: head size (length, width, area and perimeter), shape (ellipticity, rugosity, elongation and regularity) and tail length. Diff...
It is well known that the plasma membranes of mammalian spermatozoa undergo extensive remodeling during maturation in the epididymal duct. In this investigation, we have used fluorescence recovery after photobleaching (FRAP) techniques to: 1) measure rates of lipid diffusion in the plasma membrane of mouse spermatozoa at different stages of maturation; 2) examine the effects of varying external...
T evolution of sperm traits manifests itself prolifically across species, and postcopulatory sexual selection (PSS), as executed by the female, accompanies this process. The adaptive significance of some sperm traits (for example, the shape and number of sperms) is well understood. However, the evolution of germ size has not been fully exploited. The most recent study by Lüpold et al.1 reveals ...
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