Female Reproductive Performance Research Articles

Testicular transcriptional signatures associated with high fertility.

Factors of high fertility are poorly described. The majority of transgenic or knockout models with a reproductive phenotype are subfertile or infertile phenotypes. Few genotypes have been linked to improved reproductive performance (0.2%) or increased litter size (1%). In this study, we used a unique mouse model, fertility line FL1, selected for 'high fertility' for more than 170 generations. This strain has almost doubled the number of littermates as well as their total birth weight accompanied by an elevated ovulation rate and increased numbers of corpora lutea compared to a randomly mated and unselected control line (Ctrl). Here, we investigate whether the gonadal tissue of FL1 males are affected by 'co-evolution' after more than 40 years of female-focused selection. Using microarrays, we analysed the testicular transcriptome of the FL1 and Ctrl mice. These data were also compared with previously published female gonadal transcriptional alterations. We detected alterations in testicular gene expression, which are partly associated with female reproductive performance. Thus, female-focused selection for litter size has not only affected the female side, but also has been manifested in transcriptional alterations on the male gonadal organ. This suggests consequences for the entire mouse lines in the long run and emphasizes the perspective of inevitably considering both genders about mechanisms of high fertility.

Effect of multiple spawning on female reproductive output and offspring quality in a freshwater caridean shrimp with direct development

AbstractThe decline with age in components of fitness is variable among different taxa and includes changes in fertility and brood quality. In this study, we selected individuals of Neocaridina davidi, a freshwater shrimp with direct development, to analyze juvenile quality and female reproductive performance over successive spawnings, both of which are correlated with female age. Given the high costs of reproduction in species with direct development, we hypothesized that female reproductive performance and juvenile quality decrease in later spawns. Two experiments were performed. In Experiment 1, we evaluated the reproductive performance of females of N. davidi and the quality of juveniles (through a food restriction test) over the first six successive spawnings. In Experiment 2, we analyzed the lipid and protein contents in juveniles from the third, fourth, and fifth spawns, after feeding them daily or starving them for 8 d or 12 d after hatching. Female mortality was observed throughout Experiment 1, along with a decrease in the proportion of ovigerous females over successive spawns. However, the interval between spawnings and the number and size of newly hatched juveniles were similar among spawns. Moreover, females that spawned many times had a reproductive efficiency similar to those that spawned few times, as evidenced by a similar percentage of broods successfully hatched and a similar percentage of broods with more than 28 juveniles among all spawns. Overall, these results may indicate a partial effect of multiple spawning on female reproductive performance. Growth, survival, and biochemical composition of food‐restricted juveniles showed similar or even higher values in later spawns as compared to the first spawns. This is, to our knowledge, the first empirical demonstration in a decapod crustacean with direct development that, although the percentage of ovigerous females decreases over time, other reproductive variables and juvenile performance do not decline in successive spawnings, at least for the initial six consecutive spawns.

Ecologically-relevant exposure to methylmercury during early development does not affect adult phenotype in zebra finches (Taeniopygia guttata).

Methylmercury causes behavioural and reproductive effects in adult mammals via early developmental exposure. Similar studies in birds are limited and mostly focussed on aquatic systems, but recent work has reported high blood mercury concentrations in terrestrial, passerine songbirds. We used the zebra finch (Taeniopygia guttata) as a model to explore the long-term effects of early developmental exposure to methylmercury exposure. Chicks were dosed orally with either the vehicle control, 0.0315 µg Hg/g bw/day, or 0.075 µg Hg/g bw/day throughout the nestling period (days 1-21 post-hatching). We then measured (a) short-term effects on growth, development, and behaviour (time to self-feeding, neophobia) until 30 days of age (independence), and (b) long-term effects on courtship behaviour and song (males) and reproduction (females) once methylmercury-exposed birds reached sexual maturity (90 days post-hatching). High methylmercury treated birds had mean blood mercury of 0.734 ± 0.163 µg/g at 30 days post-hatching, within the range of values reported for field-sampled songbirds at mercury contaminated sites. However, there were no short-term effects of treatment on growth, development, and behaviour of chicks, and no long-term effects on courtship behaviour and song in males or reproductive performance in females. These results suggest that the nestling period is not a critical window for sensitivity to mercury exposure in zebra finches. Growing nestlings can reduce blood mercury levels through somatic growth and depuration into newly growing feathers, and as a result they might actually be less susceptible compared to adult birds receiving the same level of exposure.

Effect of aqueous/methanolic extract of Ocimum sanctum (OciBest) on the Male and Female reproductive performance of wistar rats

Background: Ocimum sanctum (OSE) has been used in the Indian system of traditional medicine (Ayurveda) for the treatment and prevention of various diseases. However, the contradictory reports regarding the reproductive safety of OSE prompted us to re-verify its effect on the reproductive system by following internationally accepted Organization for Economic Cooperation and Development guideline 415. Objective: To study the effect of aqueous/methanolic extract of OSE (OciBest) on the male and female reproductive performance of Wistar rats. Materials and Methods: Rats were orally gavaged with OciBest at dose levels of 0, 250, 500, and 1000 mg/kg. Males were administered with OciBest for 12 weeks before and during the mating period. On the other hand, females received OciBest for 2 weeks before mating until the end of the lactation period. Results: OciBest at 1000 mg/kg did not induce any adverse effects on the reproductive performance of male and female rats. All the treated parent animals survived until the end of the study period with no major signs of clinical toxicity. The body weights, food consumption, male and female fertility indices, organ weights, as well as gross pathological and histopathology observations in parent animals, did not reveal any treatment-related adverse effects. Moreover, in comparison to the control groups, OciBest did not induce any treatment-related adverse effects to the offsprings. Conclusion: Thus, no-observed adverse effect level was found up to 1000 mg/kg dose, suggesting the safety of OciBest for reproductive system. Abbreviations used: OECD: Organization for Economic Cooperation and Development; NOAEL: No-observed adverse effect level; CPCSEA: Committee for the Purpose of Control and Supervision of Experiments on Animals; OA: Oleanolic acid; UA: Ursolic acid.

Genetic analysis of age at first calving, accumulated productivity, stayability and mature weight of Nellore females

The female reproductive performance, productivity and size are strongly associated with production efficiency of herds raised in a tropical environment. The age at first calving (AFC), accumulated productivity (AP), stayability (STAY) and mature weight (MW) could be used as indicators of these traits. In this study, the genetic parameters and correlations between AFC, AP, STAY and MW measured in Nellore females were estimated, in order to provide support for the beef cattle evaluation programs. In addition, the genetic changes for these traits were obtained. The (co)variance components were estimated by Gibbs sampling by four-trait multivariate analysis, using a threshold animal model for STAY and linear animal model for the other traits (AFC, AP and MW). Heritability of AFC, AP and STAY showed low values, with posterior means of 0.13 ± 0.02, 0.14 ± 0.01 and 0.19 ± 0.03, respectively. On the other hand, for MW were estimated mean heritability of 0.44 ± 0.03 and repeatability of 0.77 ± 0.03, demonstrating the importance of genetic and permanent environmental effects for the expression of beef cows' size. The AFC showed null genetic correlation with AP (−0.06 ± 0.12) and MW (0.01 ± 0.09) and low and negative with STAY (−0.15 ± 0.11). The AP showed high genetic correlation with STAY (0.86 ± 0.03) and weak with MW (0.23 ± 0.09). Positive and moderate genetic association was estimated between STAY and MW (0.66 ± 0.05). Annual direct genetic trends of 0.19 kg, 0.30 units and 0.10 kg were estimated for AP, STAY and MW, respectively, and were significant (P < 0.05) for STAY and MW. For AFC, negative and favorable annual genetic change was estimated (−0.08 months, P < 0.05). In this population, the selection of heifers for an early reproductive age should have little influence, however favorable, in the time that the cows remain in the herd. The use of AP as a selection criterion should result in smaller changes in the females' mature weight when compared to selection based on STAY.

Fipronil 1% pour-on: further studies of its effects against lab-reared Glossina palpalis gambiensis

In order to assess the residual effects of fipronil 1% on tsetse fly survival, male Glossina palpalis gambiensis were released on non-treated and treated cattle, with 0.1 ml of fipronil/kg b.w. as a pour-on formulation. In a second trial, the female fecundity performances were evaluated by feeding teneral females on the same cattle. These females were then mated and their production parameters monitored, as well as the survival of freshly emerged flies. Fipronil had a significant effect on tsetse fly survival (p < 0.001). Over a period of 30 days, up to 40% of tsetse fly mortality was observed within 72 h after tsetse were released. The residual effects ranged between 51 and 74 days when tsetse flies were released twice within a 15-day interval in the presence of a treated animal. When tsetse flies were fed on treated cattle through a parafilm membrane, 92 days after the treatment, no significant effect of fipronil was observed on the reproductive performance of females, i.e., as well as on fecundity (p = 0.948) and emergence rates (p = 0.743), or puparial weight (p = 0.422). This was also the case for the survival of young flies, with no difference observed between the two groups. After this study, it is confirmed that fipronil is highly effective against tsetse flies. Its efficacy in controlling ticks is already known but other externalities such as the control of biting insects add value to its use.

The increased expression of follicle-stimulating hormone leads to a decrease of fecundity in transgenic Large White female pigs.

Follicle-stimulating hormone (FSH) is a pituitary gonadotropin regulating reproduction in mammals. Overexpression of the exogenous FSHα/β genes from Chinese Erhualian pigs improved female fecundity of transgenic (TG) mice and male spermatogenesis ability of Large White TG boars. Here, we investigated the impact of the exogenous FSHα/β genes on female reproductive performance of Large White TG pigs. First, we identified the integration site of the exogenous FSHα/β genes at 140,646,456bp on chromosome 9 in these TG pigs using whole-genome sequencing. Then, we showed that TG gilts had higher levels of serum FSH and FSHβ protein in pituitary while had a potentially lower number of born piglets than their wild-type half sibs. TG gilts grew healthily and normally without significant difference in growth and health parameters as compared to WT gilts. The expression levels of FSHR, LHR, ESR1 and ESR2 were significantly lower in TG gilts than in WT gilts at the age of 300days. Taken together, we proposed that the overexpressed FSHα/β transgenes could cause deteriorate fecundity via disturbing the normal expression of the endogenous reproduction-related genes in female pigs. Our findings provide insight into the effect of overexpression of FSHα/β on female reproduction performance in pigs.

Impact of male condition on his spermatophore and consequences for female reproductive performance in the Glanville fritillary butterfly.

In butterflies, male reproductive success is highly related to the quality and the size of the spermatophore transferred to the female. The spermatophore is a capsule produced by the male during copulation, which in many species contains sperm in addition to a nuptial gift, and which is digested by the female after copulation. The nuptial gift may contribute to egg production and offspring quality, and in some cases also to female body maintenance. The production of the spermatophore, however, represents a cost for the male and, in polyandrous species, ejaculates are sometimes allocated adaptively across matings. Nonetheless, although the ecological factors affecting the reproductive success of female butterflies have been the topic of numerous studies, little information exists on the factors affecting males' contribution to reproduction, and the indirect impacts on female fecundity and fitness. We used the Glanville fritillary butterfly, Melitaea cinxia (Linnaeus, 1758) (Nymphalidae), in order to assess variation in male allocation to matings. In this species, smaller males produce smaller spermatophores, but variation in spermatophore size is not correlated with female reproductive success. We show that spermatophore size increases with male age at first mating, decreases with mating frequency and adult food-deprivation, and is not influenced by developmental food-limitation. The length of copulation period does not influence the spermatophore size nor influences the polyandrous mating behavior in this species. Male contribution to his spermatophore size is clearly influenced by his condition and adult-resource at the time of mating. Despite this variation, spermatophore size does not seem to have a direct impact on female reproductive output or mating behavior.

No effect of partner age and lifespan on female age‐specific reproductive performance in blue tits

Studies of age‐specific reproductive performance are fundamental to our understanding of population dynamics and the evolution of life‐history strategies. In species with bi‐parental care, reproductive ageing trajectories of either parent may be influenced by their partner's age, but this has rarely been investigated. We investigated within‐individual age‐specific performance (laying date and number of eggs laid) in wild female blue tits Cyanistes caeruleus and evaluated how the age and longevity of their male partner indirectly influenced the females’ reproductive performance. Females showed clear age‐dependence in both laying date and number of eggs laid. We found that female reproductive performance improved in early life, before showing a decline. Longer‐lived females had an earlier laying date throughout their lives than shorter‐lived females, but there was no difference in number of eggs laid between longer‐ and shorter‐lived females. Within breeding pairs, the female's (age‐specific) reproductive performance was not dependent on the age and longevity of the male partner. We conclude that the age and quality of the male partner may be of little importance for traits that are under direct female control.

The effect of male incubation feeding on female nest attendance and reproductive performance in a socially monogamous bird

The incubation of eggs plays a key role in avian parental care. To ensure embryo development, incubating parents have to keep their eggs within the appropriate temperature limits. To do so, incubating individuals allocate substantial energy to the thermal demands of their eggs, but they face a trade-off with self-maintenance (own metabolism) because they usually cannot forage while incubating eggs. In species with female-only incubation, males can help their partners by providing them with food on the nest, a behavior which may enable females to spend more time incubating and could, consequently, lead to improved reproductive performance. In the study reported here, we first investigated whether incubation feeding by males affects nest attendance by females in Blue Tits (Cyanistes caeruleus) and subsequently determined how this incubation feeding affects reproductive performance. We found that the female nest attendance tended to increase with increasing amounts of food supplied by their male partner. Thus, males may enable females to incubate more when needed, as suggested by our observation that male incubation feeding was more frequent when the ambient temperature was lower, and especially so when females incubated later in the breeding season (during the study period the ambient temperature decreased rapidly over the breeding season, which is exceptional). Although female nest attendance did not result in a shorter time until the eggs hatched or in higher hatching success, females that attended the nest more produced heavier nestlings. We suggest that the trade-off between self-maintenance and meeting the demands of egg incubation likely tends to be less when females received more assistance from their partner during the egg incubation period, resulting in a higher investment in offspring.

Effects of arachidonic acid supplementation in maturation diet on female reproductive performance and larval quality of giant river prawn (Macrobrachium rosenbergii).

The giant river prawn (Macrobrachium rosenbergii) is one of the most farmed freshwater crustaceans in the world. Its global production has been stalling in the past decade due to the inconsistent quality of broodstock and hatchery-produced seeds. A better understanding of the role of nutrition in maturation diets will help overcome some of the production challenges. Arachidonic acid (20:4 n-6, ARA) is a fatty acid precursor of signaling molecules important for crustacean reproduction, prostaglandins E and F of the series II (PGE2 and PGF2α), and is often lacking in maturation diets of shrimp and prawns. We examined the effects of ARA in a combination of different fish oil (FO) and soybean oil (SO) blends on females’ reproductive performance and larval quality. Adult females (15.22 ± 0.13 g and 11.12 ± 0.09 cm) were fed six isonitrogenous and isolipidic diets containing one of two different base compositions (A or B), supplemented with one of three levels of Mortierella alpine-derived ARA (containing 40% active ARA): 0, 1 or 2% by ingredient weight. The two base diets differed in the percentages of (FO and SO with diet A containing 2% SO and 2% FO and diet B containing 2.5% SO and 1.5% FO, resulting in differences in proportional contents of dietary linoleic acid (18:2n-6, LOA) and docosahexaenoic acid (22:6n-3, DHA)). After the eight-week experiment, prawns fed diet B with 1 and 2% ARA supplement (B1 and B2) exhibited the highest gonadosomatic index (GSI), hepatosomatic index (HSI), egg clutch weight, fecundity, hatching rate, number of larvae, and reproductive effort compared to those fed other diets (p ≤ 0.05). Larvae from these two dietary treatments also had higher tolerance to low salinity (2 ppt). The maturation period was not significantly different among most treatments (p ≥ 0.05). ARA supplementation, regardless of the base diet, significantly improved GSI, HSI, egg clutch weight and fecundity. However, the diets with an enhanced ARA and LOA (B1 and B2) resulted in the best reproductive performance, egg hatchability and larval tolerance to low salinity. These dietary treatments also allow for effective accumulation of ARA and an n-3 lcPUFA, DHA in eggs and larvae.

Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction.

Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.

Effect of leaf chemistry ofVitis viniferaL. on the performance and development ofEpiphyas postvittana(Lepidoptera: Tortricidae)

Background and Aims In the context of life-history performance, better fitness is evident in insect populations when they correlate positively with the nutritional quality of their host-plants. We determined the chemical differences in the leaves of five cultivars of Vitis vinifera in relation to feeding by Epiphyas postvittana and evaluated larval and adult reproductive performance on the selected cultivars. Methods and Results We determined total nitrogen, carbohydrates, phenolic substances and potassium, iron, sodium and zinc in V. vinifera cv. Chardonnay, Sauvignon Blanc, Merlot, Semillon and Marsanne. The life-history performance of E. postvittana was evaluated by raising it from eggs on leaves of the cultivars. Nitrogen content of Chardonnay was significantly greater than that of the other cultivars. Different cultivars of V. vinifera influenced growth parameters such as larval-developmental time and female-pupal mass. Reproductive-performance, measured as fecundity and fertility rates and adult-male longevity, varied when reared on leaves of the cultivars of V. vinifera. Conclusion Leaves of Chardonnay have the highest nitrogen concentration and enhanced larval performance of E. postvittana. A fitness-index study shows that female-reproductive performance was significantly enhanced when reared on Chardonnay, whereas it declined when reared on Marsanne. Significance of the Study Differences among cultivars of V. vinifera in terms of leaf chemistry are critical for larval performance and adult-reproductive potential. The poor response of E. postvittana on Marsanne could be useful in integrated pest management via push—pull strategy by planting Marsanne either near or among the susceptible cultivars of V. vinifera.

Active parental care, reproductive performance, and a novel egg predator affecting reproductive investment in the Caribbean spiny lobster Panulirus argus

We used the Caribbean spiny lobster Panulirus argus, one of the largest brooding invertebrates in the Western Atlantic, to test for the presence/absence of active parental care and to explore reproductive performance in large brooding marine organisms. Given [i] the compact and large embryo masses produced by P. argus, [ii] the expected disproportional increase in brooding costs with increasing embryo mass size, and [iii] the theoretical allometry of egg production with increasing body size, we predicted that parental females in this large species will engage in active brood care. We also predicted that larger broods from larger lobsters should suffer higher mortality and brood loss than smaller broods from smaller lobsters if parental care was minimal or absent. Lastly, we expected smaller females to allocate disproportionably more resources to egg production than larger females in the case of minimal parental care. Females brooding early and late embryos were collected from different reefs in the Florida Keys Reef tract, transported to the laboratory, and maintained in separate aquaria to describe and quantify active parental care during day and night. A second set of females was retrieved from the field and their carapace length, fecundity, egg size, reproductive output and presence/absence of brood-dwelling pathogens was recorded. Laboratory experiments demonstrated that brooding females of P. argus engaged in active brood care. Females likely use some of the observed behaviors (e.g., abdominal flapping, pleopod beating) to provide oxygen to their brood mass. In Panulirus argus, females did not suffer brood loss during embryo development. Also, reproductive output increased more than proportionally with a unit increase in lobster body weight. Our results agree with the view that large brooding marine invertebrates can produce large embryo masses if they engage in active parental care and that the latter behavior greatly diminishes reproductive performance costs associated with producing large embryo masses. Lastly, we report on a nemertean worm that, we show, negatively impacts female reproductive performance.

Carcass Age and Reproductive Costs forNicrophorus orbicollis(Coleoptera: Silphidae)

The life history costs of living in microbially dense environments can be high. To assess the importance of these costs for natural selection, it is necessary to know how costs vary with environmental conditions. Adult burying beetles prepare vertebrate carcasses of varying age and states of deterioration as a resource for their young. In the present study, Nicrophorus orbicollis Say females were presented with either fresh or aged (80 h) large carcasses (30-39 g) to examine effects on their lifetime reproductive success (four reproductive attempts) and survival. Reproductive success and survival were also measured for female offspring that developed on fresh and aged carcasses. Carcass age had no measurable effect on lifetime reproductive output or life span of either parents or their adult offspring. In a separate experiment using medium-sized carcasses (22-24 g), the reproductive performance of females in a single reproductive attempt was negatively affected by carcass age (13.9% less brood mass). The results suggest that the costs of using a single older carcass are relatively minor when measured over a lifetime. Alternative costs of using older carcasses and explanations for the complex antimicrobial traits of burying beetles are discussed.

Additive genetic, non-additive genetic and permanent environmental effects for female reproductive performance in seasonal calving dairy females

AbstractExcellent reproductive performance (i.e. 365-day calving interval) is paramount to herd profit in seasonal-calving dairy systems. Reproductive targets are currently not being achieved in Irish dairy herds. Furthermore, most research on the genetics of reproductive performance in dairy cattle has focused primarily on lactating cows and relatively few studies have attempted to quantify the genetic contribution to differences in reproductive performance in nulliparae. The objective of the present study was to estimate the contribution of both the additive and non-additive genetic components, as well as the permanent environmental component, to phenotypic variation in the reproductive traits in nulliparous, primiparous and multiparous seasonal-calving dairy females. Reproductive phenotypes were available on up to 202,525 dairy females. Variance components were estimated using (repeatability where appropriate) linear animal mixed models; fixed effects included in the mixed models were contemporary group, parity (where appropriate), breed proportion, inter-breed specific heterosis coefficients and inter-breed specific recombination loss coefficients. Heritability of the reproductive traits ranged from 0.004 (pregnancy rate to first service) to 0.17 (age at first service in nulliparae), while repeatability estimates for the reproductive traits in cows ranged from 0.01 (calving interval) to 0.11 (pregnant in the first 42 days of the breeding season). Breed-specific heterosis regression coefficients suggest that, relative to the parental mean, a first-cross Holstein–Jersey crossbred was almost 7 days younger at first calving, had a 9-day shorter calving interval, a 6 percentage unit greater pregnancy rate in the first 42 days of the breeding season and a 3 percentage unit greater survival rate to next lactation. Heifer calving rate traits were strongly genetically correlated with age at first calving (–0.97 to –0.66) and calving rate in the first 42 days of the calving season for first parity cows (0.77 to 0.56), but genetic correlations with other cow reproductive traits were weak and inconsistent. Calving interval was strongly genetically correlated with the majority of the cow traits; 56%, 40%, and 92% of the genetic variation in calving interval was explained by calving to the first service interval, number of services and pregnant in the first 42 days of the breeding season, respectively. Permanent environmental correlations between the reproductive performance traits were generally moderate to strong. The existence of contributions from non-additive genetic and permanent environmental effects to phenotypic differences among cows suggests the usefulness of such information to rank cows on future expected performance; this was evidenced by a stronger correlation with future reproductive performance for an individual cow index that combined additive genetic, non-additive genetic and permanent environmental effects compared to an index based solely on additive genetic effects (i.e. estimated breeding values).

The effects of N-acetyl-l-cysteine on the female reproductive performance and nephrotoxicity in rats

This study was designed to investigate whether the treatment with the N-acetyl-l-cysteine prior to the administration of chemotherapy drug would prevent from nephrotoxicity and the loss of reproductive performance induced from chemotherapy treatment. Female rats were divided into five equal groups of six each: 1/control group; 2/rats i.p administered saline solution; 3/rats i.p administered holoxan (50 mg/kg b.wt); 4/rats i.p administered N-acetyl-l-cysteine (160 mg/kg b.wt); 5/rats i.p administered holoxan and N-acetyl-l-cysteine at the same doses. After medications, females rats were allowed to mate with males and the pregnant rats were sacrificed on day 18 of gestation. Premating treatment with holoxan showed reduction (p < 0.05) in reproductive performance. Whereas administration of N-acetyl-l-cysteine prior to treatment with holoxan and then concurrently with it modulated significantly fertility index, progesterone level, decreasing postimplantation loss, resorbed fetuses and improved fetal growth. Additionally, holoxan elevated the renal nicotinamide dinucleotide phosphate (NADPH) oxidase activity, oxidative stress, renal functions and caused histological changes in renal tissue. N-Acetyl-l-cysteine treatment reduced (p < 0.05) renal tissue NADPH oxidase, nitric oxide, malondialdehyde and improved super oxide dismutase (SOD) depletion, elevated levels phosphate, total protein and calcium as well as prevented renal histological damages. N-Acetyl-l-cysteine can confer protection against nitrosative and oxidative stresses in renal tissue induced by holoxan by suppressing NADPH oxidase activation, malondialdehyde, nitric oxide and restoring SOD activity which led to the reduction of reactive oxygen species production and subsequently might effectively improve the gonadal hormone disturbance and reproductive functions.

Condition dependence of male and female reproductive success: insights from a simultaneous hermaphrodite.

Sexually selected traits are predicted to show condition dependence by capturing the genetic quality of its bearer. In separate-sexed organisms, this will ultimately translate into condition dependence of reproductive success of the sex that experiences sexual selection, which is typically the male. Such condition dependence of reproductive success is predicted to be higher in males than females under conditions promoting intense sexual selection. For simultaneous hermaphrodites, however, sex allocation theory predicts that individuals in poor condition channel relatively more resources into the male sex function at the expense of the female function. Thus, male reproductive success is expected to be less condition dependent than female reproductive success. We subjected individuals of the simultaneously hermaphroditic snail Physa acuta to two feeding treatments to test for condition dependence of male and female reproductive success under varying levels of male-male competition. Condition dependence was found for female, but not for male, reproductive success, meaning that selection on condition is relatively stronger through the female sex function. This effect was consistent over both male-male competition treatments. Decomposition of male and female reproductive performance revealed that individuals in poor condition copulated more in their male role, indicating an increased male allocation to mate acquisition. These findings suggest that sex-specific condition dependence of reproductive success is at least partially driven by condition-dependent sex allocation. We discuss the implications of condition-dependent sex allocation for the evolution of sexually selected traits in simultaneous hermaphrodites.

Study on the Survival and Reproductive Performance of Sterile Male &amp;lt;i&amp;gt;Glossina pallidipes&amp;lt;/i&amp;gt;

Laboratory investigation was conducted to know the effect of irradiation (sterility) on reproductive performance of females G. pallidipes mated with sterile and fertile males under temperature of 23-25°C and 75-80% relative humidity. Completely randomized designs with three replications were followed throughout the experiments. The irradiation effects on male G. pallidipes at different doses of irradiation were checked using, 60Gy, 80Gy, 100Gy and 120Gy. Results showed that at highest doses the sterility effects on male Glossina pallidipes were significantly lower than lowest doses (P<0.05) on pupae production and emergence of adults. On the other hand, the highest dose (120Gy) caused abortion of egg/larvae significantly higher than the lower dose (60Gy) (P<0.05). In other investigation which was aimed to assessing the competitiveness of sterile malestofertile males in a cage at ratios of 9 sterile: 1 fertile males, 7 sterile to 3 fertile males, 5 sterile to 5 fertile males and 3 sterile to 7 fertile males, the results showed that the ratio with the highest number of sterile (9:1) in the cage caused significantly low number of pupae and number of adults emerged from pupae than those with lower number of sterile males (3:7) (P<0.05). Similarly, the ratio with the highest sterile males (9:1) resulted in significantly higher number of egg/larvae abortion than those with lower number of sterile males (3:7) ratio (P<0.05). In the present study, survival of male G. pallidipes irradiated with 120Gy three days after emergence from pupae was significantly higher than males irradiatedone and ten days after emergence from pupae (P<0.05). This may indicate that irradiated males may need to rest up to 7 or 10 days before released to the field. The importance of sterilization using appropriate dose, the appropriate ratio of sterile to fertile males and the time at which sterility was done efficiently all are relevant.

Plumage colour is associated with partner parental care in mutually ornamented tree swallows

Sexually selected traits can signal an individual's ability to contribute offspring care. Differential allocation theory posits that when these same traits also influence brood value, it may be adaptive for partners to adjust care in response to their mates' traits. Evaluating the strength and direction of parental quality signalling and differential allocation is thus essential to understand selection on ornamental traits. We examined relationships between plumage colour and parental care in tree swallows, Tachycineta bicolor , a mutually ornamented species in which plumage colour is related to male and female reproductive performance. Using a model of avian vision to quantify parental colour trait variation, we found that male and female tree swallows that were paired to partners with greener, more saturated plumage colour fed offspring at higher rates. Among tree swallow pairs where both partners were in their second year of breeding or older, individuals with greener, more saturated plumage colour also fed their offspring at higher rates. We show that offspring of males that provisioned more often tended to achieve greater body mass independent of the colour traits of their parents. Our results suggest a role for partner parental care in selection on female ornamentation in this species. • Female tree swallows have greener-coloured plumage than males. • Birds paired to greener-coloured partners feed offspring more often. • Offspring of males that provision more often achieve greater body mass. • Greener-coloured birds may thus obtain benefits through partner reproductive allocation.