Search results for "sperm"
showing 10 items of 658 documents
Apoptosis rate in human spermatozoa is not related to nuclear vacuoles
2012
Effects of work exposure to electromagnetic waves and organic compounds on sperm DNA fragmentation in patients undergoing ICSI
2011
In spermatozoa collected after pellet swim up, when total dna fragmentation is higher than 15%, the normal morphologically spermatozoa population sho…
2020
Study question: We investigated the DNA Fragmentation Index (DFI) in motile normal morphologically spermatozoa comparing samples with total DFI < 15% Vs ≥ 15% collected after pellet swim up Summary answer: In the case of DFI ≥15% the percentage of normal morphologically spermatozoa with fragmented DNA is significantly higher than the population with DFI < 15% What is known already: Intracytoplasmic sperm injection (ICSI) is widely used in the treatment of male infertility. Only morphologically normal spermatozoa are mainly used by embryologists to fertilize an oocyte. Different papers have reported that spermatozoa with apparently normal morphology may have DNA fragmentation. These ev…
The Stagnone of Marsala lagoon
2009
The Stagnone of Marsala is an oligotrophic lagoon situated on the western coast of Sicily. The area has been under study since the mid-nineteenth century. Research has focused on its physiographic, chemical-physical, biological, ecological features and, particularly, on submerged vegetation. Its main biotic component, a meadow of Posidonia oceanica, is distributed among peculiar reef formations inside and outside the lagoon, which are extremely interesting from an ecological and environmental point of view. The seagrass grows near to its thermal and salinity tolerance level in the inner lagoon, where it is partially replaced by Cymodocea nodosa and Caulerpa prolifera meadows. Algal assembla…
The genus Ruppia L. (Ruppiaceae) in the Mediterranean region: An overview
2015
Abstract This paper reviews the current knowledge on the diversity, distribution and ecology of the genus Ruppia L. in the Mediterranean region. The genus Ruppia, a cosmopolitan aquatic plant complex, is generally restricted to shallow waters such as coastal lagoons and brackish habitats characterized by fine sediments and high salinity fluctuations. In these habitats Ruppia meadows play an important structural and functional role. Molecular analyses revealed the presence of 16 haplotypes in the Mediterranean region, one corresponding to Ruppia maritima L., and the others to various morphological forms of Ruppia cirrhosa (Petagna) Grande, all together referred to as the “R. cirrhosa s.l. co…
PCAF catalyzes tha acetylation of spermidine to N8-acetylspermidine and regulates its acetylating activity on histones
2011
Post-transcriptional histone acetylation is a well known process playing a crucial role in chromatin assembly and transcription. Here, we report that PCAF, a highly conserved histone acetyltransferase (HAT), can efficiently catalyze acetylation of spermidine to N8-acetylspermidine, at low concentration. Remarkably, we found that spermidine at higher concentration can also inhibit PCAF HAT activity directed against histone H3 in vitro, confirming the in vivo data referred by Eisenberg et al. on the spermidine induced inhibition of H3 acetylation. Surprisingly when we performed HAT assay experiments at low spermidine concentration we observed an activating effect on PCAF on H3 acetylation. Ou…
Una nuova colorazione istochimica delle cellule germinali maschili. Sali di argento e sale aureo per l'esame dello sperma di coniglio.
2007
Molecular analyses on HPV infections in semen
Introduction: Human Papillomaviruses (HPVs) are non-enveloped double stranded DNA viruses classified in different genera and several different genotypes. Depending on the genotypes, HPV infections can be asymptomatic or can cause from warts to malignant tumours. Some genotypes, such as HPV18 and HPV16, are considered high risk (HR) HPVs and they are the major cause of cervical cancer. HPV is highly tissue-tropic and infects epithelial cells, but it can also binds other cell types. It is known that HPV can be found in semen but its effects on spermatozoa and male reproductive system are not completely clarified. Materials and Methods: In order to study the HPV infection in semen, we develope…
Sexual Selection Within the Female Genitalia in Lepidoptera
2015
The genitalia of male and female Lepidoptera are complex organs, composed of several structures that exhibit great diversity of shapes, sizes, and positions, suggesting that they have evolved in a relatively rapid and divergent way. In this chapter, we explore the selective pressures responsible for the evolution of genital morphology in the Lepidoptera , emphasizing the possible role of post-copulatory intersexual selection (PCIS) mechanisms (cryptic female choice and sexual conflict). Our exploration is in great extent speculative because knowledge on the functional morphology of genitalia in this group is limited. We start by describing the complexity and diversity of genitalia in Lepido…
Sperm competition and small size advantage for males of the golden orb-web spider Nephila edulis
2000
Sexual selection, through female choice and/or male‐male competition, has influenced the nature and direction of sexual size dimorphism in numerous species. However, few studies have examined the influence of sperm competition on size dimorphism. The orb-web spider Nephila edulis has a polygamous mating system and extreme size dimorphism. Additionally, the frequency distribution of male body size is extremely skewed with most males being small and few large. The duration of copulation, male size and sexual cannibalism have been identified as the significant factors determining patterns of sperm precedence in spiders. In double mating trials, females were assigned to three treatments: either…