Science is facing a new RNA world that shaping our knowledge, and we are discovering horizon in molecular biology. New technologies revealed thousands of RNAs, most them located what was once known as the “dark matter DNA”. They functional regulatory RNAs do not code for proteins, they orchestrate cellular function according to changes needed. These noncoding ubiquitous, present from viruses hu...

BACKGROUND Sperm binding proteins and their C-terminal peptides of the Sperm Associated Antigen 11 (SPAG11) family were found to play an important role in epididymal innate immunity in addition to their role in sperm maturation. However, the expression of Spag11 transcripts in rodents is not well documented. METHODS Computational analysis was employed to identify novel Spag11 isoforms in the ...

The spermatozoon is the most diverse cell type known and this diversity is considered to reflect differences in sperm function. How the diversity in sperm morphology arose during speciation and what role the different specializations play in sperm function, however, remain incompletely characterized. This work reviews the hypotheses proposed to explain sperm morphological evolution, with a focu...

Freeze-storage of epididymal sperm is an important technique for the preservation of gametes in animals, including those becoming extinct. We froze canine sperm recovered from the cauda epididymis and investigated the fertility. The qualities of sperm from the cauda epididymis before freezing were: mean sperm motility, 89.4 +/- 1.6 (SE) %; sperm viability, 89.1 +/- 1.1%; and these were signific...

In polyandrous species, sperm morphometry and sperm velocity are under strong sexual selection. Although several hypotheses have been proposed to explain the role of sperm competition in sperm trait variation, this aspect is still poorly understood. It has been suggested that an increase in sperm competition pressure could reduce sperm size variation or produce a diversity of sperm to maximize ...

the objective of this study was to evaluate the importance of environmental and genetic factors affecting semen quality; sperm volume (sv), sperm concentration (spco), total sperm (ts), fresh sperm motility (fsm), total fresh motile sperm (tfms), post thaw sperm motility (ptsm), total post thaw motile sperm (tptms), number of produced payout (npp), number of fresh motile sperm in each milt ejac...

Past studies have suggested that mouse sperm surface galactosyltransferase may participate during fertilization by binding N-acetylglucosamine (GlcNAc) residues in the zona pellucida. In this paper, we examined further the role of sperm surface galactosyltransferase in mouse fertilization. Two reagents that specifically perturb sperm surface galactosyltransferase activity both inhibit sperm-zon...

Spermatozoa are amongst the most variable cells, and three factors are thought to account for this variation in design: fertilization mode, phylogeny, and postcopulatory sexual selection. In addition, it has long been assumed that a tradeoff exists between sperm size and number, and although postcopulatory sexual selection affects both traits, empirical evidence for a tradeoff has so far been e...

BACKGROUND The aim of this study was to determine if only sperm with double stranded DNA could bind to the human zona pellucida (ZP). METHODS Sperm samples from 124 infertile men with a range of semen abnormalities were studied. Oocytes that had failed to fertilize in IVF or ICSI were used for the sperm-ZP binding test. A group of four oocytes were incubated for 2 h with 2 x 10(6)/ml motile s...

Sperm competition is generally thought to drive the evolution of sperm miniaturization. Males gain advantage by transferring more sperm, which they produce by dividing limited resources into ever smaller cells. Here, we describe the opposite effect of size on the competitiveness of amoeboid sperm in the hermaphroditic nematode Caenorhabditis elegans. Larger sperm crawled faster and displaced sm...