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DNA methylation analysis is becoming increasingly useful in biomedical research and forensic practice. The discovery of differentially methylated sites (DMSs) that continuously change over an individual's lifetime has led to breakthroughs in molecular age estimation. Although semen samples are often used in forensic DNA analysis, previous epigenetic age prediction studies mainly focused on somatic cell types. Here, Infinium MethylationEPIC BeadChip arrays were applied to semen-derived DNA samples, which identified numerous novel DMSs moderately correlated with age. Validation of the ten most age-correlated novel DMSs and three previously known sites in an independent set of semen-derived DNA samples using targeted bisulfite massively parallel sequencing, confirmed age-correlation for nine new and three previously known markers. Prediction modelling revealed the best model for semen, based on 6 CpGs from newly identified genes SH2B2 , EXOC3 , IFITM2 , and GALR2 as well as the previously known FOLH1B gene, which predict age with a mean absolute error of 5.1 years in an independent test set. Further increases in the accuracy of age prediction from semen DNA will require technological progress to allow sensitive, simultaneous analysis of a much larger number of age correlated DMSs from the compromised DNA typical of forensic semen stains.

Background: Curcumin is a phytochemical derived from rhizome of turmeric Curcuma longa, present in the curry spice. Recently, it has attracted the attention of researchers and clinicians as an anti-inflammatory and anti-oxidant agent with a potential use in therapy of many diseases with an inflammatory component. Interestingly, curcumin despite its very low bioavailability showed protective activity against many organ lesions., Methods: In the present study we investigated the effects of curcumin treatment on mice semen quality parameters in vitro and on semen and testicular damage induced by di(2-ethylhexyl)phthalate in vivo., Results: The study demonstrated protective effects of low concentrations (1-50 μM) of curcumin on mouse sperm motility in vitro and on DEHP-induced damage of seminiferous tubules in testes and its ability to diminish the decrease in sperm motility in vivo. In contrast, curcumin used in high concentration (100 μM) decreased sperm motility and viability in vitro., Conclusion: The effects of curcumin were dependent on its concentration. In male germ cells in vivo the protective effect was seen despite the low bioavailability of curcumin. In contrast, high, unattainable in the organism, concentration of curcumin had a cytotoxic effect on male reproductive cells in vitro. Curcumin also had a protective effect against the harmful impact of DEHP on the male reproductive system., (Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.)

Curcumin is a natural compound derived from rhizome of Curcuma longa. It is an active compound of turmeric used from millennia in traditional medicine. At present there is a very rich scientific documentation describing curcumin as an anticancer, antioxidative and antiinflammatory compound. Research on animal models revealed its not only anticancer activity but also potency as a drug against many other diseases of low grade inflammatory origin. Curcumin also counteracts many induced organ injuries. On the cellular level curcumin inhibits proliferation and induces apoptosis, however it is less cytotoxic for cancer than normal cells. There are many molecular targets of curcumin but stress signaling pathways and inhibition of NF- kappaB transcription factor seems to be the most common. Despite its low bioactivity curcumin can exert beneficial influence on organism, thus confirming its hormetic propensity.

Cell cycle regulation in Eukaryotes is based on common molecular actors and mechanisms. However, the canonical cell cycle is modified in certain cells. Such modifications play a key role in oocyte maturation and embryonic development. They can be achieved either by introduction of new components, pathways, substrates, changed interactions between them, or by elimination of some factors inherited by the cells from previous developmental stages. Here we discuss a particular temporal regulation of the first embryonic M-phase of Xenopus and mouse embryos. These two examples help to understand better the general regulation of M-phase of the cell cycle.

Here, we outline the mechanisms involved in the regulation of cell divisions during oocyte maturation and early cleavages of the mouse embryo. Our interest is focused on the regulation of meiotic M-phases and the first embryonic mitoses that are differently tuned and are characterized by specifically modified mechanisms, some of which have been recently identified. The transitions between the M-phases during this period of development, as well as associated changes in their regulation, are of key importance for both the meiotic maturation of oocytes and the further development of the mammalian embryo. The mouse is an excellent model for studies of the cell cycle during oogenesis and early development. Nevertheless, a number of molecular mechanisms described here were discovered or confirmed during the study of other species and apply also to other mammals including humans.

The first mitosis of the mouse embryo is almost twice as long as the second. The mechanism of the prolongation of the first mitosis remains unknown, and it is not clear whether prometaphase or metaphase or both are prolonged. Prometaphase is characterized by dynamic chromosome movements and spindle assembly checkpoint activity, which prevents anaphase until establishment of stable kinetochore-microtubule connections. The end of prometaphase is correlated with checkpoint inactivation and disappearance of MAD2L1 (MAD2) and RSN (CLIP-170) proteins from kinetochores. Spindle assembly checkpoint operates during the early mouse mitoses, but it is not clear whether it influences their duration. Here, we determine the length of prometaphases and metaphases during the first two embryonic mitoses by time-lapse video recording of chromosomes and by immunolocalization of MAD2L1 and RSN proteins. We show that the duration of the two prometaphases does not differ and that MAD2L1 and RSN disappear from kinetochores very early during each mitosis. The first metaphase is significantly longer than the second one. Therefore, the prolongation of the first embryonic mitosis is due to a prolonged metaphase, and the spindle assembly checkpoint cannot be involved in this process. We show also that MAD2L1 staining disappears gradually from kinetochores of oocytes arrested at metaphase of the second meiotic division. This shows a striking similarity between the first embryonic mitosis and metaphase arrest in oocytes. We postulate that the first embryonic mitosis is prolonged by a transient metaphase arrest that is independent of the spindle assembly checkpoint and is similar to metaphase II arrest. The molecular mechanism of this transient arrest remains to be elucidated.