Search results for "spermatozoa"
showing 10 items of 183 documents
Dog sperm head morphometry: its diversity and evolution
2017
Dogs have been under strong artificial selection as a consequence of their relationship with man. Differences between breeds are evident that could be reflected in seminal characteristics. The present study was to evaluate differences in sperm head morphometry between seven well-defined breeds of dog: the British Bulldog, Chihuahua, German Shepherd, Labrador Retriever, Spanish Mastiff, Staffordshire Terrier, and Valencian Rat Hunting dog. Semen samples were obtained by masturbation and smears stained with Diff-Quik. Morphometric analysis (CASA-Morph) produced four size and four shape parameters. Length, Ellipticity, and Elongation showed higher differences between breeds. MANOVA revealed di…
Enhancer blocking activity located near the 3′ end of the sea urchin early H2A histone gene
1997
The sea urchin early histone repeating unit contains one copy of each of the five histone genes whose coordinate expression during development is regulated by gene-specific elements. To learn how within the histone repeating unit a gene-specific activator can be prevented to communicate with the heterologous promoters, we searched for domain boundaries by using the enhancer blocking assay. We focused on the region near the 3′ end of the H2A gene where stage-specific nuclease cleavage sites appear upon silencing of the early histone genes. We demonstrated that a DNA fragment of 265 bp in length, defined as sns (for silencing nucleoprotein structure), blocked the enhancer activity of the H2A…
Effects of exposure to static magnetic fields on the morphology and morphometry of mouse epididymal sperm.
1998
Morphologic and morphometric sperm characteristics of mouse epididymal extracts from animals exposed to static magnetic fields were evaluated. For this purpose, animals were exposed for 35 days to a field of 0.7 T generated by a commercial permanent magnet for either 1 or 24 h per day. The values of morphometric parameters were obtained using the morphometric module of the Sperm Class Analyzer® computerized image analysis system, and percentages of abnormalities were calculated. The size of sperm heads was unaffected by exposure to static magnetic fields. Lack of hook was a sperm head abnormality found significantly more frequently in animals exposed continually than in nonexposed animals, …
Is sperm motility maturation affected by static magnetic fields?
1996
Kinematic parameters were evaluated in mouse epididymal extracts to monitor maturation of sperm movement in animals exposed to static magnetic fields using the Sperm-Class Analyzer computerized image analysis system. For this purpose, animals were exposed to a field of 0.7 T generated by a permanent magnet over 10 or 35 days for either 1 or 24 hr/day. The values of the motion endpoints were similar in animals used as controls and in those exposed to the nonionizing radiation, whatever the period of exposure or daily dosage. Changes in motility were observed in all groups: the percentage of total motile and progressive motile spermatozoa increased during passage through the epididymis, with …
Seminal plasma biochemistry and spermatozoa characteristics of Atlantic cod (Gadus morhua L.) of wild and cultivated origin
2011
Abstract Our objectives were to compare spermatozoa activity, morphology, and seminal plasma (SP) biochemistry between wild and cultivated Atlantic cod ( Gadus morhua ). Swimming velocities of wild cod spermatozoa were significantly faster than those of cultivated males. Wild males had a significantly larger spermatozoa head area, perimeter, and length, while cultivated males had more circular heads. Total monounsaturated fatty acids and the ratio of n−3/n−6 were significantly higher in sperm from wild males, while total n−6 from cultivated males was significantly higher than the wild males. Significantly higher concentrations of the fatty acids C14:0, C16:1n−7, C18:4n−3, C20:1n−11, C20:1n−…
Disrupting immune regulation incurs transient costs in male reproductive function.
2014
9 pages; International audience; BACKGROUND: Immune protection against pathogenic organisms has been shown to incur costs. Previous studies investigating the cost of immunity have mostly focused on the metabolic requirements of immune maintenance and activation. In addition to these metabolic costs, the immune system can induce damage to the host if the immune response is mis-targeted or over-expressed. Given its non-specific nature, an over-expressed inflammatory response is often associated with substantial damage for the host. Here, we investigated the cost of an over-expressed inflammatory response in the reproductive function of male mice. METHODOLOGY/PRINCIPAL FINDINGS: We experimenta…
Scanning electron microscopy of heterochromatin in chromosome spreads of male germ cells in Schistocerca gregaria (Acrididae, Orthoptera) after tryps…
1996
Chromosome spreads, prepared from testes of the desert locust Schistocerca gregaria, were analyzed using scanning electron microscopy (SEM) after varying periods of preincubation in trypsin. The emphasis of the study was on the appearance of heterochromatin. A trypsin pretreatment of 5 sec resulted in a smooth surface on the chromatin throughout and the heterochromatin was highly electron-emissive. The facultatively heterochromatic X chromosome was clearly visible in interphase spermatogonia and in pachytene and late prophase I spermatocytes. Chromomeres of autosomal bivalents could be recognized in pachytene cells. Centromeric heterochromatin segments were very prominent in autosomes of la…
Male Investments in High Quality Sperm Improve Fertilization Success, but May Have Negative Impact on Offspring Fitness in Whitefish.
2015
Many ejaculate traits show remarkable variation in relation to male social status. Males in disfavoured (subordinate) mating positions often invest heavily on sperm motility but may have less available resources on traits (e.g., secondary sexual ornaments) that improve the probability of gaining matings. Although higher investments in sperm motility can increase the relative fertilization success of subordinate males, it is unclear whether status-dependent differences in sperm traits could have any consequences for offspring fitness. We tested this possibility in whitefish (Coregonus lavaretus L.) by experimentally fertilizing the eggs of 24 females with the sperm of either highly-ornamente…
Sperm DNA integrity and human papillomavirus (HPV) infections: a controversy that could be resolved by a new molecular approach
2020
Study question: The aim was to determine if HPVs affect spermatozoa DNA integrity. To resolve the discrepancy regarding the association between HPV infections and sperm DNA damage. Summary answer: To elucidate if HPV impairs DNA integrity, we suggest to investigate HPV DNA positivity in spermatozoa by a differential lysis procedure before TUNEL assay.
Male fertility in long-term survivors of childhood ALL.
1999
A study of fertility was conducted in postpubertal male patients who had been treated for acute lymphoblastic leukemia (ALL) during childhood or adolescence between 1970 and 1980. Thirteen men (age 18 to 35 years) participated on a volunteer basis. Their age at diagnosis was between 2 and 15 years. Therapy followed the protocol ''Memphis VII (Pinkel)." Interview, physical examination, andrological studies (ejaculate), and hormone status (luteinizing hormone, follicle-stimulating hormone, and testosterone) were performed at least 5 years after completion of therapy. No normozoospermia was achieved; 10 patients were identified with asthenozoospermia and 3 patients with azoospermia. With respe…