Early social instability affects plasma testosterone during adolescence but does not alter reproductive capacity or measures of stress later in life.

The social environment plays an important role in modulating processes of the hormonal and behavioural profile of an animal in a variety of group-living species. In wild cavies for instance, unstable social environmental conditions during pregnancy and lactation lead to an infantilised biobehavioural profile of the male offspring. In the present study, the influence of the social environment during pregnancy and lactation on the male wild cavy offsprings' plasma testosterone development, reproductive capacity and stress system activity was investigated. To this purpose, 12 sons whose mothers had lived in an unstable social environment during pregnancy and lactation were compared with 12 sons whose mothers had lived in a stable social environment during the same time. Plasma testosterone (T) and plasma cortisol (C) concentrations were determined from days 20 to 107 of age. Adrenal tyrosine hydroxylase (TH) activity and different parameters of reproductive capacity (weights of testes, epididymides and accessory sex glands, cellular composition of the testes, DNA fragmentation indices and sperm motility parameters) were analysed at day 107 of age. TH activity and plasma C were unaffected by different social environmental conditions early in life. The developmental time course of T concentrations, however, was significantly different: Sons whose mothers had lived in an unstable social environment during pregnancy and lactation showed a delayed increase in T concentrations around adolescence compared to controls. In contrast, no reproduction-related parameters measured within this study differed significantly between the two groups. Thus, early social instability affects plasma testosterone development during adolescence in a significant way but does not alter reproductive capacity or measures of stress later in life.

Heterochromatin instability in cancer: from the Barr body to satellites and the nuclear periphery.

In recent years it has been recognized that the development of cancer involves a series of not only genetic but epigenetic changes across the genome. At the same time, connections between epigenetic regulation, chromatin packaging, and overall nuclear architecture are increasingly appreciated. The cell-type specific organization of heterochromatin, established upon cell differentiation, is responsible for maintaining much of the genome in a repressed state, within a highly compartmentalized nucleus. This review focuses on recent evidence that in cancer the normal packaging and higher organization of heterochromatin is often compromised. Gross changes in nuclear morphology have long been a criterion for pathologic diagnosis of many cancers, but the specific nuclear components impacted, the mechanisms involved, and the implications for cancer progression have barely begun to emerge. We discuss recent findings regarding distinct heterochromatin types, including the inactive X chromosome, constitutive heterochromatin of peri/centric satellites, and the peripheral heterochromatic compartment (PHC). A theme developed here is that the higher-order organization of satellites and the peripheral heterochromatic compartment may be tightly linked, and that compromise of this organization may promote broad epigenomic imbalance in cancer. Recent studies into the potential role(s) of the breast cancer tumor suppressor, BRCA1, in maintaining heterochromatin will be highlighted. Many questions remain about this new area of cancer epigenetics, which is likely more important in cancer development and progression than widely appreciated. We propose that broad, stochastic compromise in heterochromatin maintenance would create a diversity of expression profiles, and thus a rich opportunity for one or more cells to emerge with a selective growth advantage and potential for neoplasia.

[Peculiarities of digital dermatoglyphics and the somatic status in female athletes engaged in fencing].

The article presents the morphogenetic performance of 31 female athlete aged 18-23 years specializing in fencing, compared to women of the same age group not involved in professional sports. The research program included: evaluation of a complex of anthropometric parameters (longitudinal, transverse, circumferential body sizes), somatotype diagnostics using of Heath-Carter method, evaluation of body composition, qualitative and quantitative characteristics of digital dermatoglyphics (pattern type, ridge count, delta index, a combination of phenotypic patterns), determination of sex chromatin content in the epithelial cells of the oral cavity mucous membrane. The study demonstrated that the somatic status of female fencers could be defined as a balanced mesomorphic somatotype with the prevailing mesomorphic vector. The proportion of muscular component in female athletes was higher, while that of the fat mass was lower than the similar parameters in the control group. The athletes were characterized by the peculiarities of dermatoglyphic constitution: high values of delta index and the total ridge count, higher proportion of complex patterns and minimal amount of simple patterns. In female athletes, significantly lower amounts of sex chromatin were demonstrated as compared to those not engaged in sports.

Sex chromosome silencing in the marsupial male germ line.

In marsupials, dosage compensation involves silencing of the father's X-chromosome. Because no XIST orthologue has been found, how imprinted X-inactivation occurs is unknown. In eutherians, the X is subject to meiotic sex chromosome inactivation (MSCI) in the paternal germ line and persists thereafter as postmeiotic sex chromatin (PMSC). One hypothesis proposes that the paternal X is inherited by the eutherian zygote as a preinactive X and raises the possibility of a similar process in the marsupial germ line. Here we demonstrate that MSCI and PMSC occur in the opossum. Surprisingly, silencing occurs before X-Y association. After MSCI, the X and Y fuse through a dense plate without obvious synapsis. Significantly, sex chromosome silencing continues after meiosis, with the opossum PMSC sharing features of eutherian PMSC. These results reveal a common gametogenic program in two diverse clades of mammals and support the idea that male germ-line silencing may have provided an ancestral form of mammalian dosage compensation.

Origin of DNA damage in ejaculated human spermatozoa.

The molecular basis of many forms of male infertility is poorly defined. One area of research that has been studied intensely is the integrity of the DNA in the nucleus of mature ejaculated spermatozoa. It has been shown that, in men with abnormal sperm parameters, the DNA is more likely to possess strand breaks. However, how and why this DNA damage originates in certain males and how it may influence the genetic project of a mature spermatozoon is unknown. Two theories have been proposed to describe the origin of this DNA damage in mature spermatozoa. The first arises from studies performed in animal models and is linked to the unique manner in which mammalian sperm chromatin is packaged, while the second attributes the nuclear DNA damage in mature spermatozoa to apoptosis. One of the factors implicated in sperm apoptosis is the cell surface protein, Fas. In this review, we discuss the possible origins of DNA damage in ejaculated human spermatozoa, how these spermatozoa arrive in the ejaculate of some men, and what consequences they may have if they succeed in their genetic project.

[Activity of W-sex heterochromatin and accumulation of the nuage in nurse cells of the lepidopteran Ephestia]. / Activité de l'hétérochromatine sexuelle-W et accumulation du nuage dans les cellules nourricières du lépidoptère Ephestia.

In the Lepidopteran Ephestia, in the female sex, the W chromosome, with which no function is known to be associated, is, in whole or part, maintained in a heterochromatic state in all cellular categories, except for the oocyte. In the present work, however, W-sex heterochromatin (W-SH) is demonstrated by ultrastructural autoradiography to be transcriptionally active in nurse cells during previtellogenesis. This activity is accompanied by accumulation of "nuage" in the perinuclear cytoplasm, both phenomena arresting at the beginning of vitellogenesis. We have performed kinetic analysis of the labeling associated with W-SH and with nuage through a pulse-chase experiment, together with high resolution examination of the structures visible in the vicinity of active W-SH. Our results suggest that W-SH transcripts are packaged and transported to the cytoplasm within polyparticles typically resembling the hnRNP particles--the structures packaging (pre)messenger RNA which are isolated from the nuclei of numerous Eukaryotes--and that they are concentrated within the nuage upon leaving the nucleus. Such findings explain the close relationship observed in Ephestia, both in space and time, between the nuage and active W-SH. In different organisms, including Drosophila, the nuage has been proposed to be a site of assembly of germ plasm. Considering this hypothesis as well as our results with Ephestia, we speculate that the activity of W-SH detected in nurse cells reflects the expression of one or several genes located within the heterochromatin of the W chromosome, and that the function of these genes is related with the elaboration of germ plasm. The implications raised by these unexpected proposals are mentioned.

Síndrome de Turner 45,XO asociado con una inversión pericéntrica del cromosoma 13 / Turner's syndrome 45, XO associated with a pericentric inversion of chromosome 13

El propósito del presente trabajo es el de describir a una paciente con manifestaciones clínicas del síndrome de Turner, quien al realizarle los estudios cromosómicos en cultivo de linfocitos de sangre periférica, y con técnicas de bandas G, mostró un complemento cromosómico de 45, XO y además una inversión pericéntrica del cromosoma 13 con sus puntos de ruptura en las bandas pll y ql4. Los padres y el hermano de la propósita presentaron un cariotipo normal. Se discuten los mecanismos probables de origen de ambas anomalías y los pocos casos reportados en la literatura

Kinetics of corneal epithelial maintenance and graft loss. A population balance model.

We use a population balance model to study the mechanism and the rate of centripetal migration of epithelial cells, renewal of the corneal epithelial population by the cell derived from (progeny of) the limbal stem cells and the kinetics of the replacement of the donor corneal epithelium. The epithelial mass is constant under the normal circumstances and therefore the rate of cellular entry due to centripetal motion and mitosis into any epithelial volume must equal the cell loss from the same volume. The magnitude of the centripetal velocity and the rate of replacement of the donor tissue following keratoplasty are shown to depend only on the following directly quantifiable factors--the difference in the mitotic rates of the corneal and limbal epithelia and the radii of these two epithelia. The a priori model predictions are found to be in very good agreement with the observed centripetal velocities and the rate of corneal graft replacement. The model provides an independent support for the hypothesis that the stem cells for the corneal epithelium are located in the limbus and are responsible for a slow replenishment of the corneal epithelial cell. The model suggests some factors that diminish the centripetal supply of cells and thus provides insights into the pathogenesis of persistent corneal defects and delayed reepithelialization of defects and grafts. The model is suitable for interpreting and quantitatively correlating the influence of some epithelial alterations and drugs on the centripetal supply of epithelial cells.

Penetration of hamster and pig zona-free eggs by boar ejaculated spermatozoa preincubated in vitro.

The hamster and pig zona-free eggs were successfully penetrated in vitro by boar ejaculated and washed sperm, which had been preincubated in vitro in a chemically defined medium supplemented with calf serum proteins. The fertilization results and rate of polyspermy were found to be mainly dependent on sperm concentration at preincubation and on the time of sperm preincubation and fertilization. However, the pig zona-free eggs were penetrated also by the freshly washed boar sperm, but as early as 8 hours after semination. In this case the spermatozoa probably also capacitate on the surface of the egg plasma membrane. The fertilization of zona-free eggs with preincubated sperm results in higher penetration rate and very high polyspermy as early as 4 hours after semination.

Influence of seminal plasma on the chromatin stability of ejaculated human spermatozoa.

Nuclear chromatin decondensation (NCD) of human ejaculated spermatozoa exposed to sodium dodecyl sulphate (SDS) has been studied. A high proportion of NCD reacting spermatozoa was only found in semen samples with a relatively low activity of some prostatic factor(s) (i.e. zinc/fructose ratio below 0.18) in the seminal plasma. Exposure to SDS for one h was found sufficient to reveal the main proportion of spermatozoa undergoing NCD in such a solution. Addition of seminal plasma with an apparently normal composition to a sperm population with a high NCD reactivity restored the sperm SDS resistance to normal, i.e. blocked the NCD-response. Other results indicated that NCD reactivity was decreased or abolished upon prolonged storage of the spermatozoa in the seminal plasma. The various results indicated that some factor(s) in the seminal plasma can preserve the nuclear chromatin stability of human spermatozoa and that this factor most likely is of prostatic origin.

Thyroid-bound Y-chromatin-like fluorescence in the nuclei of thyroid adenomas.

Brilliantly fluorescent supernumerary chromocenters indistinguishable from the Y-chromatin have been often found electively in the thyroid nuclei. The authors compared the occurrence of this Y-chromatin-like fluorescence in 31 thyroid adenomas obtained from 30 autopsy cases (10 males, 20 females) with non-adenomatous thyroid tissues of the same cases. All adenomas had follicular structure but one with papillary structure. The frequency class of Y-chromatin-like fluorescence of adenomas was lower in 15 cases out of 31 than that of the same non-adenomatous thyroid tissue. The Y-chromatin-like fluorescence had a negative count in 13 cases of 31 adenomas but only in 3 cases of normal thyroid tissues from 30 persons. The disappearance of the nuclei with Y-chromatin-like chromocenters is supposedly connected with cellular dedifferentiation of thyroid adenomas.

[Secretory type and the X-sex chromatin characteristics of persons with peptic ulcer]. / Sekretoren tip i X-polovo khromatina kharakteristika pri litsa s iazvena bolest

Blood groups according to ABO and Rh systems were tested in 137 ulcer patients as well as the secretory state. The titre of blood group ABH antigens was determined in the same patients, secreted in saliva and gastric juice. The results are compared with those obtained from the examination of a control group of 30 clinically healthy subjects. X-sex chromatin in the cells of biopsy mucosa was examined in 40 ulcer patients, taken from the ulcer area after gastroscopy. As a control, X-sex chromatin was studied in smears from exfoliated oral mucosa in the same subjects. The data confirm the presence of genetic predisposition to ulcer disease development in subjects from blood group O (alpha, beta) and non-secretory type. Low titres of blood group antigens were found in the secretory patients. Differences in X-sex chromating characteristics were observed between bucal mucosa and the mucosa from the ulcer area.

Role of chromatin in estrogen action in the uterus. II. Hormone-induced synthesis of nonhistone acidic proteins which restore histone-inhibited DNA-dependent RNA synthesis.

Nonhistone acidic proteins were isolated, by equilibrium density centrifugation in 4 M cesium chloride, from the chromatin isolated and purified from the uterus of the ovariectomized rat or from calf endometrium. Evidence is presented to show (1) that arginine-rich histones are more effective inhibitors of chromatin-directed RNA synthesis in vitor than lysine-rich histones, (2) that the nonhistone acidic proteins of chromatin do not inhibit the synthesis of RNA directed by chromatin in vitro, (3) that added nonhistone acidic chromatin proteins effect a restoration of histone-inhibited RNA synthesis directed by chromatin in vitro, and (4) that the synthesis of nonhistone acidic chromatin proteins is under estrogen control in the uterus, but not in the liver. It is concluded that a major feature of the early action of estrogen in the uterus of the ovariectomized rat is the stimulation of synthesis and the accumulation in the interphase chromosomes of nonhistone acidic proteins which counter the inhibitory effect of histone on transcription by RNA polymerase. Presumably this would permit more and perhaps a new synthesis of RNA programmed for transport to the cytoplasm.