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Importance of sperm morphology during sperm transport and fertilization in mammals
After natural or artificial insemination, the spermatozoon starts a journey from the site of deposition to the place of fertilization. However, only a small subset of the spermatozoa deposited achieves their goal： to reach and fertilize the egg. Factors involved in controlling sperm transport and fertilization include the female reproductive tract environment, cell-cell interactions, gene expression, and phenotypic sperm traits. Some of the significant determinants of fertilization are known （i.e., motility or DNA status）, but many sperm traits are still indecipherable. One example is the influence of sperm dimensions and shape upon transport within the female genital tract towards the oocyte. Biophysical associations between sperm size and motility may influence the progression of spermatozoa through the female reproductive tract, but uncertainties remain concerning how sperm morphology influences the fertilization process, and whether only the sperm dimensions per se are involved. Moreover, such explanations do not allow the possibility that the female tract is capable of distinguishing fertile spermatozoa on the basis of their morphology, as seems to be the case with biochemical, molecular, and genetic properties. This review focuses on the influence of sperm size and shape in evolution and their putative role in sperm transport and selection within the uterus and the ability to fertilize the oocyte.
Journal Article
Good quality : the routinization of sperm banking in China
\"From its crude and uneasy beginnings thirty years ago, Chinese sperm banking has become a routine part of China's pervasive and restrictive reproductive complex. Today, there are sperm banks in fifteen of China's twenty-two provinces, the biggest of which screen some 2,000-3,000 potential donors each year. With an estimated one to two-million azoospermic men--those who are unable to produce their own sperm--the demand remains insatiable. China's fifteen sperm banks cannot keep up, spurring sperm bank directors to publicly lament chronic shortages and even warn of a national 'sperm crisis' (jingzi weiji). Good quality explores the issues behind the crisis, including declining sperm quality in the country due to environmental pollution, as well as a chronic national shortage of donors. Whalberg also outlines the specific style of Chinese sperm banking that has been shaped by the particular cultural, juridical, economic and social configurations that make up China's restrictive reproductive complex. Good Quality shows how this high-throughput style shapes the ways in which men experience donation and sperm is made available to couples who can afford it\"--Provided by publisher.
Book
Major regulatory mechanisms involved in sperm motility
The genetic bases and molecular mechanisms involved in the assembly and function of the flagellum components as well as in the regulation of the flagellar movement are not fully understood, especially in humans. There are several causes for sperm immotility, of which some can be avoided and corrected, whereas other are related to genetic defects and deserve full investigation to give a diagnosis to patients. This review was performed after an extensive literature search on the online databases PubMed, ScienceDirect, and Web of Science. Here, we review the involvement of regulatory pathways responsible for sperm motility, indicating possible causes for sperm immotility. These included the calcium pathway, the cAMP-dependent protein kinase pathway, the importance of kinases and phosphatases, the function of reactive oxygen species, and how the regulation of cell volume and osmolarity are also fundamental components. We then discuss main gene defects associated with specific morphological abnormalities. Finally, we slightly discuss some preventive and treatments approaches to avoid development of conditions that are associated with unspecified sperm immotility. We believe that in the near future, with the development of more powerful techniques, the genetic causes of sperm immotility and the regulatory mechanisms of sperm motility will be better understand, thus enabling to perform a full diagnosis and uncover new therapies.
Journal Article
Whales
Introduces sperm whales, including their different body parts, how they travel in groups, what they eat, and how they care for their young.
Book
Use of testicular sperm in couples with SCSA-defined high sperm DNA fragmentation and failed intracytoplasmic sperm injection using ejaculated sperm
Sperm DNA fragmentation (SDF) has been linked with male infertility, and previous studies suggest that SDF can have negative influence on pregnancy outcomes with assisted reproduction. We performed a retrospective review of consecutive couples with a high SDF level that had intracytoplasmic sperm injection (ICSI) using testicular sperm (T-ICSI). We compared the T-ICSI outcomes to that of two control groups: 87 couples with failed first ICSI cycle and who had a second ICSI cycle using ejaculated sperm (Ej-ICSI), and 48 consecutive couples with high sperm chromatin structure assay (SCSA)-defined SDF (>15%) that underwent an ICSI cycle using ejaculated sperm after one or more failed ICSI cycles (Ej-ICSI-high SDF). The mean number of oocytes that were retrieved and the total number of embryos were not different among the three groups. The mean number of transferred embryos in the T-ICSI group was higher than the Ej-ICSI group but not significantly different than the Ej-ICSI-high SDF group (1.4, 1.2, and 1.3, respectively, P < 0.05). Clinical pregnancy rate in the T-ICSI group was not significantly different than the Ej-ICSI and Ej-ICSI-high SDF groups (48.6%, 48.2%, and 38.7%, respectively, P > 0.05). No significant difference was found in live birth rate when comparing T-ICSI to Ej-ICSI and Ej-ICSI-high SDF groups. The results suggest that pregnancy outcomes and live birth rates with T-ICSI are not significantly superior to Ej-ICSI in patients with an elevated SCSA-defined sperm DNA fragmentation and prior ICSI failure(s).
Journal Article
After the peace
\"How many parents does it take to make a baby? In the case of Rosalind Melrose Smithson it took four: one birth mother; one legal father; one interfering neighbour and one turkey baster filled with the defrosted essence of an anonymous donor. Or not so anonymous as it turned out. For donor no. 116349, '6ft 1in, blue eyes, blond hair, BA (Oxon), action man, aristocrat' is the ninth Earl of Dilberne, who gave his seed back in 1979 as a stripling of twenty-two, and has now conceived a daughter - unknowingly - at the riper age of forty-two. As they say, the truth will out. And what will our Rozzie do when she finds out about dear old dad? All we know is that as a true Millennial, she will not take it lying down... Sharp, insightful and full of Weldon's trademark wit, this is a tale of family life, genetics and class that reflects the way we live our lives now\"-- Publisher's description.
Book
In the heart of the sea : the epic true story that inspired Moby Dick
The sinking of the whaleship Essex by an enraged spermwhale in the Pacific in November 1820 set in motion one of the most dramatic sea stories of all time: the twenty sailors who survived the wreck took to three small boats and only eight of them survived their subsequent 90-day ordeal. This work presents this story of maritime disaster.
Book
Effect of transient scrotal hyperthermia on sperm parameters, seminal plasma biochemical markers, and oxidative stress in men
In this experimental prospective study, we aimed to analyze the effect of transient scrotal hyperthermia on the male reproductive organs, from the perspective of sperm parameters, semen plasma biochemical markers, and oxidative stress, to evaluate whether different frequencies of heat exposure cause different degrees of damage to spermatogenesis. Two groups of volunteers （10 per group） received testicular warming in a 43~C water bath 10 times, for 30 min each time： group 1：10 consecutive days; group 2： once every 3 days. Sperm parameters, epididymis and accessory sex gland function, semen plasma oxidative stress and serum sex hormones were tested before treatment and in the 16-week recovery period after treatment. At last, we found an obvious reversible decrease in sperm concentration （P = 0.005 for Group 1 and P = 0.008 for Group 2 when the minimums were compared with baseline levels, the same below）, motility （P= 0.009 and 0.021, respectively）, the hypoosmotic swelling test score （P-- 0.007 and 0.008, respectively）, total acrosin activity （P = 0.018 and 0.009, respectively）, and an increase in the seminal plasma malondialdehyde concentration （P = 0.005 and 0.017, respectively）. The decrease of sperm concentration was greater for Group 2 than for Group 1 （P = 0.031）. We concluded that transient scrotal hyperthermia seriously, but reversibly, negatively affected the spermatogenesis, oxidative stress may be involved in this process. In addition, intermittent heat exposure more seriously suppresses the spermatogenesis compared to consecutive heat exposure. This may be indicative for clinical infertility etiology analysis and the design of contraceptive methods based on heat stress.
Journal Article