Different Phases Of Reproduction Research Articles

Cambios en el estado hematológico en función de la fase reproductiva de ovejas infectadas naturalmente por parásitos internos en el noreste de Argelia

In Algeria, sheep farming is still largely traditional, and ewes are subject to various pathologies, particularly parasitic diseases leading to reproductive failure and production losses. To assess the influence of internal parasites (helminths and protozoa) and their interaction with the different phases of reproduction and season on hematological parameters, fecal and blood samples (n = 89) were taken from ewes during the period from the end of gestation to 3 months after parturition, two weeks apart. Animals were reared under a traditional pasture–based farming system in a Region of Northeastern Algeria characterized by a Mediterranean climate. Parasitic coproscopy results showed the consistent presence of digestive strongyles, Strongyloides, Trichuris ovis, Moniezia spp., Fasciola hepatica, and Coccidia. Hematological parameters, mainly hematocrit (HCT), hemoglobin (HGB), and erythrocytes (RBC), showed lower levels in anemic ewes throughout the study period. These hematological effects became significantly prevalent in 91% of the animals (P<0.05) during the third month postpartum (p.p.). The use of a mixed–effects model confirmed the significant hematological effect (P<0.05) of internal parasitism, which was amplified significantly by its interaction with the reproduction stage for HCT and RBC (P<0.01). Monitoring of blood biological constants in ewes during the critical reproductive stages seems to provide valuable data to improve their welfare and resistance to potential internal parasites.

Влияние агониста бета3-адренорецепторов мирабегрона на активность нейтрофилов венозной крови небеременных женщин

The aim of this paper was to determine the effect of the beta3-adrenergic receptor agonist mirabegron on the free-radical activity of venous blood neutrophils in non-pregnant women. Materials and methods. Using the chemiluminescent method (BChL-07 biochemiluminometer), the parameters of the radical response of venous blood neutrophils in 40 non-pregnant women were determined in different phases of the cycle and on the first day after childbirth with additional cell stimulation with latex particles (0.08 μm). When the noise level was automatically subtracted, the following were recorded: maximum intensity of the synthesis of reactive oxygen species, time to reach the maximum of synthesis intensity, and area under the chemiluminogram curve, reflecting the total synthesis of radical particles over the course of 30 min. These parameters were determined before and after an in vitro introduction of the beta -adrenergic receptor agonist mirabegron (10–6 g/l), beta-adrenergic receptor blocker propranolol hydrochloride (10–6 g/l) and agonist against the background of the blocker into the venous blood. Results. Using the Wilcoxon signed-rank test, we showed an increase in the free-radical activity of neutrophils in women in the follicular phase of the menstrual cycle under the influence of mirabegron for all three evaluated parameters. In the luteal phase, mirabegron significantly increased the rate of reaction development and the total synthesis of radical particles, but did not affect the intensity of production of activated oxygen species. However, no effect was observed on the first day after delivery. The possible mechanism of the revealed mirabegron action is discussed in the article. The authors believe that changes in the activity of venous blood neutrophils under the action of mirabegron may be due to changes in the quantity or sensitivity of beta3-adrenergic receptors in different phases of reproduction.

Study on Uterine Environment of Buffaloes during Different Reproductive Phases

This study was undertaken to examine the changes in composition of hormonal and biochemical constituents of uterine secretions of buffaloes (n = 35) during different phases of reproduction, i.e., proestrus, estrus, metestrus and diestrus and anestrus condition. The protein fractioning of blood and uterine secretions was carried out by Gel electrophoresis. Most of the hormonal and biochemical parameters studied revealed higher levels at the estrus phase, indicating peak metabolic activity at the time of estrus, ovulation and fertilization period. The role of enzymes and macro-micro-minerals levels are also reported and discussed. Of the 35 different protein fractions (18 to 192 kDa) observed, the numbers of protein bands present in blood sera were 15 and in uterine fluid secretions 28, of which 8 were common in both the fluids. The findings between normal cyclic and anestrus conditions may be useful to find out the cause-effect relationship of infertility in buffaloes.

Identification of aquaporin-1a gene transcript in Cyprinus carpio (Linnaeus, 1758) and its expression during reproduction

Aquaporins (AQPs) are a family of membranebound proteins that facilitate the hydration of cells. The identification of the AQP1a gene in common carp (Cyprinus carpio) from mRNA transcript and its expression analysis during reproduction was performed to study its role in gonad cell hydration. The AQP1a gene transcript was partially amplified using gene-specific primers and the amino acid sequence was predicted. Based on the partial transcript sequence, a phylogenetic tree was prepared using the MEGA4 software which suggested that the AQP1a gene of common carp is closely related to that of Danio rerio. Differential tissue expression was analysed using real-time PCR which indicated that the expression of AQP1a was significantly higher in the eye, kidney, and liver with 32.98±1.33 folds higher in the eye when compared to the testis. In both the male and female gonads, the highest expressions were observed after 6h of synthetic hormone injection in comparison to gonads belonging to the individual without any injection. However, the gene expression declines gradually in 12h and 24h post-injection. Expression analysis of gonad during different phases of reproduction suggests that there is a significant increment of AQP1a expression from the resting phase to the pre-spawning phase and from pre-spawning to spawning phase in the case of male gonad. However, there was no significant difference in expression during the resting and pre-spawning phase in the female gonad, although expression was significantly higher during the spawning phase. Key words Aquaporin; Gonad; Reproduction: Common carp; gene expression

Histological organization and surface ultrastructure of ovaries of Gudusia chapra during different phases of reproduction (Teleostei: Clupeidae)

Cytological status of ovarian activities in Gudusia chapra (Hamilton, 1822) were studied during different phases of reproduction. An asynchronous development was observed in the ovaries. Variations in the ovary weight and gonadosomatic index (GSI) were also observed. Diameter of oocytes were investigated during growth, maturation and spawning phases. It was further revealed that peak of spawning period was during March to April, with a second spawning time in July.

Balancing selection maintains polymorphisms at neurogenetic loci in field experiments

Most variation in behavior has a genetic basis, but the processes determining the level of diversity at behavioral loci are largely unknown for natural populations. Expression of arginine vasopressin receptor 1a (Avpr1a) and oxytocin receptor (Oxtr) in specific regions of the brain regulates diverse social and reproductive behaviors in mammals, including humans. That these genes have important fitness consequences and that natural populations contain extensive diversity at these loci implies the action of balancing selection. In Myodes glareolus, Avpr1a and Oxtr each contain a polymorphic microsatellite locus located in their 5' regulatory region (the regulatory region-associated microsatellite, RRAM) that likely regulates gene expression. To test the hypothesis that balancing selection maintains diversity at behavioral loci, we released artificially bred females and males with different RRAM allele lengths into field enclosures that differed in population density. The length of Avpr1a and Oxtr RRAMs was associated with reproductive success, but population density and the sex interacted to determine the optimal genotype. In general, longer Avpr1a RRAMs were more beneficial for males, and shorter RRAMs were more beneficial for females; the opposite was true for Oxtr RRAMs. Moreover, Avpr1a RRAM allele length is correlated with the reproductive success of the sexes during different phases of reproduction; for males, RRAM length correlated with the numbers of newborn offspring, but for females selection was evident on the number of weaned offspring. This report of density-dependence and sexual antagonism acting on loci within the arginine vasopressin-oxytocin pathway explains how genetic diversity at Avpr1a and Oxtr could be maintained in natural populations.

A new algorithm for the identification of dives reveals the foraging ecology of a shallow-diving seabird using accelerometer data

The identification of feeding events is crucial to our understanding of the foraging ecology of seabirds. Technology has made small devices, such as time-depth recorders (TDRs) and accelerometers available. However, TDRs might not be sensitive enough to identify shallow dives, whereas accelerometers might reveal more subtle behaviours at a smaller temporal scale. Due to the limitations of TDRs, the foraging ecology of many shallow-diving seabirds has been poorly investigated to date. We thus developed an algorithm to identify dive events in a shallow-diving seabird species, the Scopoli’s shearwater, using only accelerometer data. The accuracy in the identification of dives using either accelerometers or TDRs was compared. Furthermore, we tested if the foraging behaviour of shearwaters changed during different phases of reproduction and with foraging trip type. Data were collected in Linosa Island (35°51′33″N; 12°51′34″E) from 12 June to 8 September 2015 by deploying accelerometer data loggers on 60 Scopoli’s shearwaters. Four birds were also equipped with TDRs. TDRs recorded only 17.7% of the dives detected by the accelerometers using the algorithm. A total of 82.3% of dives identified by algorithm were too short or shallow to be detected by TDRs. Therefore, TDRs were not accurate enough to detect most of the dives in Scopoli’s shearwaters, which foraged mostly close to the sea surface. Our data showed that birds performed shorter foraging trips and dived more frequently in the early chick-rearing period compared with the late chick-rearing and incubation phases. Furthermore, parents dived more frequently during short foraging trips. Our results suggest that Scopoli’s shearwaters maximised their foraging effort (e.g. number of dives, short trips) during shorter foraging trips and during early chick-rearing.

Plant–animal communication: past, present and future

Communication between plants and their animal partners underlies some of the planet’s most ecologically and economically important mutualisms. Study of communication in this context offers many opportunities to address fundamental questions about the costs and benefits of signal production, signal honesty, and receiver cognition. In this special issue, contributors highlight several key areas of current research, including how multiple receivers affect floral signaling, and how signaling may be related across different phases of reproduction. Visual signals are a particular emphasis, including how learning can mediate pollinator preferences, and the evolution of conspicuousness. In light of these focal areas, we summarize current trends towards the study of greater complexity both in terms of floral phenotypes and signaling/interaction networks.

Ascorbic acid status of female camels during different phases of reproduction

There is suggestive evidence that a low status of ascorbic acid in camels enhances their risk for infectious diseases. This study was carried out to disclose the role of reproduction, if any, in affecting ascorbic acid status. The associations between the reproductive cycle and ascorbic acid contents in plasma and leukocytes were studied in Sudanese camels browsing on local vegetation. Ascorbic acid status was found to be lowest during pregnancy and highest during lactation. Estrus versus non-estrus was associated with high vitamin C status. Brucellosis-positive camels showed decreased levels of ascorbic acid in plasma and leukocytes. Possibly, the phases of non-estrus and pregnancy in camels invoke an increased susceptibility to infectious diseases due to a lower ascorbic acid status.

Chronic corticosterone during pregnancy and postpartum affects maternal care, cell proliferation and depressive-like behavior in the dam

Stress during pregnancy and the postpartum can influence the well-being of both the mother and her offspring. Prolonged elevated levels of glucocorticoids are associated with depression and we developed an animal model of postpartum depression/stress based on high levels of corticosterone (CORT) during the postpartum. Gestational stress is a risk factor for postpartum depression and prenatal and/or postnatal high levels of CORT may have differential effects on the mother. Thus the present study was conducted to investigate the effects of low (10 mg/kg) or high levels of CORT (40 mg/kg) given to dams either during gestation, postpartum or across both gestation and postpartum on maternal care, depressive-like behavior and hippocampal cell proliferation in the dam. Only the high dose of CORT administered during the postpartum increased depressive-like behavior in the dam. Furthermore the high dose of CORT altered maternal care (reduced time spent on the nest and nursing) regardless of whether administration of CORT was during gestation or postpartum. Gestational and/or postpartum treatment with high CORT and postpartum low CORT reduced cell proliferation in the dentate gyrus of postpartum dams compared to oil-treated controls. Thus prolonged treatment with high levels of CORT postpartum reduced maternal care, hippocampal cell proliferation and induced depressive-like behavior in the dam and therefore might be considered an animal model of postpartum depression. More research is needed to understand the effects of stress hormones during different phases of reproduction and how they affect the brain and behavior of the mother and her offspring.

Does parental age affect offspring performance through differences in egg quality?

SummaryPoorer performance in young compared with older age classes is common among iteroparous animals, and may result from age effects acting on different phases of reproduction. However, such effects have generally not been teased apart, and as a result their separate consequences for offspring fitness have remained unclear.We tested whether young and mature Herring Gulls produce offspring of different quality due to differences in their egg‐production capacity. An experimental protocol was used to standardize incubation and rearing conditions.Eggs laid by young females were smaller than eggs of mature birds. They had a reduced absolute amount of albumen, which reflected mainly lower water content.Within the young age class, female eggs were smaller than male eggs and had significantly paler yolk. This was due to young birds having reduced water content of the albumen, as well as carotenoid content in eggs containing a female embryo. In the mature class there were no such differences in resource allocation in relation to embryo sex. The sex ratio of clutches did not vary with parental age.Hatchlings from eggs produced by young pairs were smaller skeletally but had similar mass to hatchlings from eggs laid by mature birds. When reared by mature foster parents, they did not differ in structural growth or survival. However, they showed a different pattern of growth in body mass.Our results suggest that poorer reproductive performance of young breeders is not simply a consequence of poorer egg quality, as this was largely compensated for when the eggs of young pairs were incubated and reared by mature foster parents. However, it is also possible that adverse effects of lower egg quality are not manifest in the offspring until later in life.

Evidence for matrotrophy in the viviparous sea cucumber Leptosynapta clarki: A role for the genital haemal sinus?

Summary Viviparity, where the embryos develop in the female reproductive system, is a rare form of reproduction in marine invertebrates, being described in only 14 species of echinoderm. In the intraovarian brooding sea cucumber, Leptosynapta clarki Heding 1928 (cf., Sewell et al. 1995), we used direct evidence (changes in energetic content) to show that significant additional nutrients are provided to the embryos during viviparous development (matrotrophy). In the transition from a structure used to produce gametes to a long-term brooding structure there are visual, histological and transmission electron microscopy (TEM) changes in the structure of the ovarian wall. Changes occur primarily in the cells of the visceral peritoneum and involve an increase in size of the connective tissue/genital haemal sinus (CT/GHS). In the latter part of the brooding period the visceral peritoneum returns to a flattened form, and new oocytes develop along the tubule wall. Similar changes in the intraovarian brooding sea cucumber Oneirophanta mutabilis affinis lead us to suggest that there is a role for the genital haemal sinus in providing nutrition during the brooding period in viviparous echinoderms. Future research is suggested to focus on changes in the ovarian wall structure during the different phases of reproduction (gamete production/brooding) in these species.

Suppression of thermogenic capacity during reproduction in primiparous brandt's voles ( Microtus brandtii)

(1) To investigate the changes of brown adipose tissue (BAT) thermogenic capacity in primiparous Brandt's voles during different phases of reproduction, BAT weight, mitochondrial protein concentration, cytochrome c oxidase (COX) activity, and uncoupling protein (UCP1) contents were measured. (2) Both cytochrome c oxidase activity and UCP1 contents decreased significantly during lactation, suggesting that thermogenic capacity was suppressed. (3) The decrease of thermogenic capacity during reproduction, especially during lactation, is compensation to the large demand of energy for reproduction. This is advantageous for energy conservation and lactation in Brandt's voles. UCP1 is the base of molecular thermogenesis of BAT in Brandt's voles.

Histomorphometric and Ultrastructural Variations in Corpus Luteum of Goat during Different Phases of Reproduction

The steroidogenic and non-steroidogenic cellular components of the corpus luteum of goat have revealed variations in their relative abundance, dimensions and fine morphology in different reproductive phases. The diameter of granulosa luteal cells was 26.052±6.83 and that of theca luteal cells was 15.000±3.11 μm during mid luteal phase of the oestrous cycle. These values were higher than those observed in the late luteal phase.

Effects of ammonium metavanadate on fertility and reproductive performance of adult male and female rats

Vanadium is a ubiquitous trace metal present in most plant and animal tissues. Environmental exposure to trivalent and pentavalent inorganic vanadium compounds has been related to impaired different phases of reproduction. Therefore, the effects of a pentavalent inorganic vanadium compound on general reproductive performance and fertility were investigated in male and female rats. Sexually mature male and female rats were exposed to 200 ppm ammonium metavanadate in drinking water. Male rats were exposed for 70 days, while the female rats exposed for 14 days premating, during mating, and throughout the whole length of gestation and lactation periods till weaning. The effects on male sex organ weights and fertility were evaluated at the end of exposure period. However, the effects on female fertility as well as developmental and postnatal effects were evaluated throughout the exposure period. The fertility was significantly reduced in both treated groups, with more pronounced suppressive effects in the male treated group. The number of implantation sites and the number of viable fetuses were significantly reduced in pregnant females of both treated groups. However, the number of resorptions, dead fetuses, and pre- and postimplantation losses were significantly increased. The incidence of resorptions was significantly increased in treated female group compared with untreated female group. The behavioral responses as well as fetal survival and viability indices were decreased in both treated groups during the lactation period. The incidence of these effects was more pronounced in the treated female group. The morphological, visceral, and skeletal anomalies were recorded significantly increased in fetuses of both treated groups, with more pronounced effects on fetuses of treated females. In conclusion, the exposure of adult male and female rats to ammonium metavanadate would cause adverse effects on fertility and reproduction.

Comparison of tRNA conformation during different phases of reproduction.

The present study is a comparison of tRNA conformation from ovary of Heteropneustes fossilis in its active phase of reproduction (when it is highly engaged in protein synthesis i.e. previtellogenic phase) with inactive phase (when tRNA is mainly stored in mature ovary i.e. spawning phase). Transfer RNA of active phase is shown to be compact, flexible and susceptible towards nuclease. Compact tRNA structure is evidenced by higher hyperchromicity and presence of relatively less Gm modifications thereby allowing adequate hydrogen bonding between D loop and T loop. Higher sensitivity of tRNA towards Mg++ reflects its higher flexibility towards internal environment. This structure of tRNA may be required for active protein synthesis. On the other hand tRNA of inactive phase is shown to be relaxed but resistant towards nuclease which may be favoured for storage in mature ova of a teleost as maternal carry over.

Optimal allocation of effort between reproductive phases: the trade-off between incubation costs and subsequent brood rearing capacity

The optimal allocation of effort during reproduction is a key component of life history theory, with trade­ offs predicted to operate both within and between reproductive attempts. Experimental work in this field has largely concentrated on the latter. The need to partition investment between different phases of reproduction, and how this varies between individuals, has received little empirical investigation. In this study, the costs of the incubation phase in common terns Sterna hirundo were increased independently of those of the egg production and brood rearing phases. Incubation of a clutch of three eggs, rather than the two originally laid, reduced the subsequent capacity of parents to provision their brood of two, demonstrating an important trade-off between reproductive phases that has generally been omitted in estimations of optimal clutch size. These results show for the first time that an increase in the costs of incubation alone, which have often been considered relatively trivial, can significantly depress parental performance later in the same breeding attempt. The effect of increased incubation costs was found to be most marked in the lower quality pairs, which demonstrates that individuals differ in their capacity to compensate for deviations from their allocation of effort to different reproductive phases.

Smoking and reproduction: Short and long term effects and benefits of smoking cessation

There have been many attempts during the last years to restrict smoking because of the significant health hazards. In particular the high prevalence of smoking among women in their reproductive years has been a matter of concern. This review was prompted in order to make the medical profession, and gynecologists in particular, confident with the underlying data. This will hopefully result in enabling them to provide balanced information to their patients, not overemphasizing the dangers of smoking, but rather presenting ways to properly recognize and treat tobacco dependence. It is a widely held view that the various risks imposed by smoking are very modest. A doubling of the risk for a rare problem may not prevent many women from continuing to smoke. However, a doubling of the risk for early miscarriage or a significant reduction of success rate in the treatment of infertility may be much more discouraging. The purpose of this review is to list the various effects smoking may have on the different phases of reproduction and to present an overview of the explanation models which have been suggested. Late effects on the child and its development will also be discussed. Hopefully, this will lead to proper concern about the problems and thus increase the motivation to quit smoking even before attempting a pregnancy. In addition, we give some hints on smoking cessation programs.

A model for the adaptive significance of partial reproductive synchrony within social units

Synchronized breeding in social units of animals (like colonies and herds) is often interpreted as a strategy against predators (predator satiation), and one might expect to find little variation in the relative date of starting reproduction. However, data on many colonies or herds show only partial synchrony. Our hypothesis is that this is not simply unavoidable variance but may be an adaption against predators. We consider the case where the members of a social unit can avoid predation actively by cooperation. If the contribution to this predator avoidance is different for individuals engaged in different phases of reproduction, our model shows that partial synchrony is of adaptive significance. Data on the black-headed gull (Larus ridibundus) are used to test the model's predictions.

Effect of lactation on the immune response to gastrointestinal nematodes.

The immune expulsion of gastrointestinal nematodes is impaired during lactation by the inhibition of the lymphocyte mediated component. As a result the population of worms may increase. At the same time, the fecundity of female worms in previously immune hosts may increase to approach that of worms in fully susceptible animals. There is good evidence that these events are primarily endocrinal in origin but although prolactin is probably involved, certain anomalies exist. These may reflect differences in the secretion pattern of the hormone in different phases of reproduction or they may indicate an interrelationship with a second hormone, for instance, adrenal glucocorticoids.