Background Infertility affects around 15% of couples, and male factors account for 50%. Cryptorchidism is one of the most common causes for azoospermia. Generation of functional spermatids from azoospermia patients is of unusual significance for treating male infertility. It has been recently reported by peers and us that human spermatogonial stem cells (SSCs) can be clearly identified and cult...

Background: We have recently shown that human embryonic (hESCs) and induced pluripotent stem cells (hiPSCs) can differentiate into advanced spermatogenic cells including round spermatids by in vitro culture (Easley et al., Direct differentiation of human pluripotent stem cells into haploid spermatogenic cells. Cell Reports 2, 440-446 2012) and also, in collaboration, that rhesus spermatogonial ...

spermatids are the earliest male germ cells with one set of haploid chromosomes. after experiments, mainly in rodents, the spermatid injection was introduced in human assisted reproduction to the treatment of men with non-obstructive azoospermia. spermatid injection is a technique with particular difficulties that may negatively influence the outcome. the identification, isolation and the asses...

Generation of functional spermatids from azoospermia patients is of unusual significance in the treatment of male infertility. Here, we report an efficient approach to obtain human functional spermatids from cryptorchid patients. Spermatogonia remained whereas meiotic germ cells were rare in cryptorchid patients. Expression of numerous markers for meiotic and postmeiotic male germ cells was enh...

Transition protein 2 (TP2), which is expressed during stages 12-15 of mammalian spermiogenesis, has been shown to undergo phosphorylation immediately after its synthesis. We reported earlier that TP2 is phosphorylated in vitro at threonine 101 and serine 109 by the salt extract of sonication-resistant (elongating and elongated) spermatid nuclei and the protein kinase phosphorylating TP2 was ide...

I have compared the quantity and the length of the poly(A) tracts of five haploid-expressed mRNAs in the polysomal and nonpolysomal fractions of round and elongating spermatids in mice: transition proteins 1 and 2, protamines 1 and 2, and an unidentified mRNA of about 1050 bases. Postmitochondrial supernatants of highly enriched populations of round and elongating spermatids (early and late hap...

Stable cytoplasmic bridges (or ring canals) connecting the clone of spermatids are assumed to facilitate the sharing of haploid gene products and synchronous development of the cells. We have visualized these cytoplasmic bridges under phase-contrast optics and recorded the sharing of cytoplasmic material between the spermatids by a digital time-lapse imaging system ex vivo. A multitude of small...

Stable cytoplasmic bridges (or ring canals) connecting the clone of spermatids are assumed to facilitate the sharing of haploid gene products and synchronous development of the cells. We have visualized these cytoplasmic bridges under phase-contrast optics and recorded the sharing of cytoplasmic material between the spermatids by a digital time-lapse imaging system ex vivo. A multitude of small...

Recent data indicate that the chromatoid body typical of rat spermatogenesis may contain RNA synthesized in early spermatids by the haploid genome. Analyses of living step-1 and step-3 spermatids by time-lapse cinephotomicrography have shown that the chromatoid body moves in relation to the nuclear envelope in two different ways. Predominantly in step 1, the chromatoid body moves along the nucl...