Many of the mechanisms by which organelles are inherited by spores during meiosis are not well understood. Dramatic chromosome motion and bouquet formation are evolutionarily conserved characteristics of meiotic chromosomes. The budding yeast bouquet genes (NDJ1, MPS3, CSM4) mediate these movements via telomere attachment to the nuclear envelope (NE). Here, we report that during meiosis the NE ...

introduction: standard semen analysis is routinly used to evaluate the male fertility, however some researchers belive that sperm functional test should also be used with standard semen analysis for more precise evaluation of male fertility. the aim of this study was to consider the relation between different nuclear maturity tests and in vitro fertilization, in order to select the nuclear matu...

Multiflagellate sperm represent a rare defect in mammals and also in the emu where an incidence of only 1% multiflagellate sperm was recorded in semen samples from 15 birds. Biflagellate sperm were the most frequent form of the defect observed, but 3- to 5-tailed sperm were also noted. An association was apparent between multiple tails and macrocephalic sperm, which accounted for 0.6% of multif...

Male infertility affects approximately 50% of all infertile couples. The male-related causes of intracytoplasmic sperm injection failure include the absence of sperm, immotile or immature sperm, and sperm with structural defects such as those caused by premature chromosomal condensation and DNA damage. Our previous studies based on a knockout mice model indicated that SEPT12 proteins are critic...

We have recently presented evidence that the structural integrity of the mouse sperm nuclear matrix may be necessary for the proper unpackaging of sperm DNA for participation in embryogenesis. It is likely that the sperm nuclear matrix contributes to the organisation of the sperm DNA and its disturbance can seriously damage the paternal genome or its expression. In this work, we confirm our pre...

Upon copulation in female Agkistrodon piscivorus, sperm migrate up the oviduct to sperm storage tubules (SSTs) in the posterior infundibulum. The epithelium of the SSTs is composed of ciliated and secretory cells and differs ultrastructurally from that of the epithelium lining the lumen of the posterior infundibulum. Sperm pass through an area composed primarily of ciliated cells at the opening...

In this and a companion paper we present immunohistochemical and ultrastructural data on hamsters infected with the Echigo-1 strain of Creutzfeldt-Jakob disease. Ultrastructurally, two types of vacuoles were readily discriminated in the brain: the grey matter vacuoles of spongiform change and intramyelin vacuoles. The vacuoles were always membrane-bound; the membranes were single or double. The...

We have been interested in determining the minimally required elements in the sperm head that are necessary in order for the paternal genome to participate in embryogenesis. We used an ionic detergent, mixed alkyltrimethylammonium bromide (ATAB), plus dithiothreitol (DTT) to remove the acrosome and almost all of the perinuclear theca, leaving only the sperm nucleus morphologically intact. We al...

There is a fundamental body of evidence suggesting that activated apoptosis signaling in ejaculated human sperm negatively influences their fertilization potential. However, it is still controversial whether this apoptotic signaling is a relic of an abortive apoptosis related to spermatogenesis or if it should be regarded as a functional preformed pathway in mature sperm leading to stereotypica...