Semen residual viral load and reproductive outcomes in HIV-infected men undergoing ICSI after extended semen preparation.

The aim of this study was to evaluate the residual presence of the human immunodeficiency virus (HIV) following a triple gradient extended semen wash from ejaculates of serodiscordant couples, and analyse their reproductive outcomes after intracytoplasmic sperm injection (ICSI). For this purpose, a retrospective analysis of our database was performed in serodiscordant couples, with HIV-infected men and non-infected women, using fresh or frozen sperm with ICSI in oocytes from either the patients or donors from January 2006 to September 2013. Overall, the rate of positive HIV test after semen washing was 1.86%. The positive beta human chorionic gonadotrophin, clinical and ongoing pregnancy rates in patients with their own oocytes were 47.1%, 37.5% and 30.8%, respectively, and 58.6%, 50.8% and 39.1%, respectively, in oocyte donation cycles. To summarize, the described method of sperm washing based on triple gradient sperm selection coupled with extensive centrifugations is a highly reliable technique for HIV removal, as it provides lower than reported post-wash positive tests while maintaining high pregnancy rates in assisted reproduction cycles. Despite extensive personnel training and effectiveness of the washing protocol, post-wash HIV test on semen is recommended to identify residual positive samples.

Histone H1 and the origin of protamines.

We present evidence that chordate protamines have evolved from histone H1. During the final stages of spermatogenesis, the compaction of DNA in many organisms is accomplished by the replacement of histones with a class of arginine-rich proteins called protamines. In other organisms, however, condensation of sperm DNA can occur with comparable efficiency in the presence of somatic-type histones or, alternatively, an intermediate class of proteins called protamine-like proteins. The idea that the highly specialized sperm chromosomal proteins (protamines) and somatic chromosomal proteins (histones) could be related dates back almost to the discovery of these proteins. Although this notion has frequently been revisited since that time, there has been a complete lack of supporting experimental evidence. Here we show that the emergence of protamines in chordates occurred very quickly, as a result of the conversion of a lysine-rich histone H1 to an arginine-rich protamine. We have characterized the sperm nuclear basic proteins of the tunicate Styela montereyensis, which we show consists of both a protamine and a sperm-specific histone H1 with a protamine tail. Comparison of the genes encoding these proteins to that of a sister protochordate, Ciona intestinalis, has indicated this rapid and dramatic change is most likely the result of frameshift mutations in the tail of the sperm-specific histone H1. By establishing an evolutionary link between the chromatin-condensing histone H1s of somatic tissues and the chromatin-condensing proteins of the sperm, these results provide unequivocal support to the notion that vertebrate protamines evolved from histones.