Human sperm has functional domains on the head and tail (flagellum). Since functional molecules are organized into the substructures of these domains, sperm with good appearance are expected to be fertile. Thus, it is of interest to see how sperm fine morphologies relate to fertility. The sperm head is divided into the acrosome and postacrosome regions. The acrosome region is further divided into the anterior acrosome for the acrosome reaction and posterior acrosome (equatorial segment) for gamete membrane fusion. The postacrosome region is involved in egg activation. In addition, the human sperm head has varieties of nuclear vacuoles. High-resolution light microscopy, which has recently been used in IMSI (intracytoplasmic morphologically selected sperm injection), is helpful in identifying vacuoles. However, IMSI is still insufficient for analysis of the contents of vacuoles; electron microscopy and evaluation tests for sperm DNA damage are more helpful for profound analysis of the nature of nuclear vacuoles and DNA status, respectively. The neck region carries the paternal centrosome to the oocyte to evoke sperm aster, from which microtubules emanate. Organization failure of the midpiece and principal piece strongly affects motility. This paper discusses the relationship beween the normality/abnormality of sperm substructures and fertility and shows typical phenotypes found in gene knockout animal models.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 25 • No. 4