Developmental programming of reproduction and fertility: what is the evidence?

The concept of the foetal/developmental origins of adult disease has been around for ~20 years and from the original epidemiological studies in human populations much more evidence has accumulated from the many studies in animal models. The majority of these have focused upon the role of early dietary intake before conception, through gestation and/or lactation and subsequent interactions with the postnatal environment, e.g. dietary and physical activity exposures. Whilst a number of theoretical models have been proposed to place the experimental data into a biological context, the underlying phenomena remain the same; developmental deficits (of single (micro) nutrients) during critical or sensitive periods of tissue growth alter the developmental pathway to ultimately constrain later functional capacity when the individual is adult. Ageing, without exception, exacerbates any programmed sequelae. Thus, adult phenotypes that have been relatively easy to characterise (e.g. blood pressure, insulin sensitivity, body fat mass) have received most attention in the literature. To date, relatively few studies have considered the effect of differential early environmental exposures on reproductive function and fecundity in predominantly mono-ovular species such as the sheep, cow and human. The available evidence suggests that prenatal insults, undernutrition for example, have little effect on lifetime reproductive capacity despite subtle effects on the hypothalamic-pituitary-gonadal axis and gonadal progenitor cell complement. The postnatal environment is clearly important, however, since neonatal/adolescent growth acceleration (itself not independent from prenatal experience) has been shown to significantly influence fecundity in farm animals. The present paper will expand these interesting areas of investigation and review the available evidence regarding developmental programming of reproduction and fertility. However, it appears there is little strong evidence to indicate that offspring fertility and reproductive senescence in the human and in farm animal species are overtly affected by prenatal nutrient exposure. Nevertheless, it is clear that the developing gonad is sensitive to its immediate environment but more detailed investigation is required to specifically test the long-term consequences of nutritional perturbations during pregnancy on adult reproductive well-being.     

Influence of mating duration on fecundity and fertility in two aphidophagous ladybirds

Abstract:  The influence of different mating durations on fecundity and fertility has been studied in two aphidophagous ladybirds, Cheilomenes sexmaculata and Coelophora saucia . Pre-oviposition period decreased while fecundity and fertility increased with increase in mating duration in both the ladybird species. The increase in fecundity with longer mating durations is probably due to the female response because of cryptic female choice. Mating of 10-s duration resulted in oviposition but of unviable eggs probably because of lack of sperm transfer. A minimum duration of 1 min of mating was probably essential for fertilization of the eggs. Absence of spermatophore in the reproductive tract of females is indicative of direct sperm transfer in both the ladybird species. Trend of fertility (similar fertility at 1 and 5 min followed by increase at 60 min which was again similar to that at complete mating) indicates probable sperm transfer in spurts in C. sexmaculata while continuous transfer in C. saucia is indicated by continuous increase in fertility with increase in mating duration.     

Effects of delayed mating on the fecundity,fertility and longevity of females of diamondback moth,Plutella xylostella

Abstract The effects of delayed mating on the copulation duration, female fertility, fecundity, egg fertility, longevity and the number days alive after mating of females of diamondback moth (DBM), Plutella xylostella, were studied. When male mating was delayed, the female fertility, fecundity, egg fertility, longevity and number days alive after mating of DBM decreased, and there was a negative correlation between the age of the moth with those variables except copulation duration. When female mating was delayed, the female fertility, fecundity, percent egg fertility and number days alive after mating of DBM also decreased, but the longevity increased, which also showed a negative relationship between the age of the moth with the variables except copulation duration and longevity. When both males and females delayed mating, the female fertility and fecundity decreased; egg fertility was affected marginally, and the longevity of females increased. The moth age was negatively correlated with those variables.     

Effect of male and female multiple mating on the fecundity, fertility, and longevity of diamondback moth, Plutella xylostella (L.)

Abstract:  The effect of diamondback moth (DBM), Plutella xylostella (Lep., Plutellidae) male and female multiple mating on fecundity, fertility, and longevity was studied. Males could mate for five times with virgin females during scotophase. The successful copulation rates, fecundity of female, and longevity of both females and males decreased when male mating times increased, whereas copulation duration increased. Correlation coefficient between copulation duration and male mating times was significant ( r  = 0.7358, P = 0.0001, spearman rank-order correlation). There were linear relationships between mating history of males and longevities of males and females, and regression relationships between them were significant. Mated females had similar daily reproductive pattern, which laid the most eggs on the first day after mating in spite of their mates' mating history. Virgin females laid some infertile eggs before they died. Most of the females mated once during their lifespan but 19.9% of females mated twice when one female kept with one male during scotophase. There were no significant differences in the fecundity, fertility and longevity between the single- and twice-mated females. Correlation coefficient between copulation duration and female mating times was not significant ( r  = 0.0860, P = 0.8575). Results suggested that DBM females may be monandrous. Multiple mating did not increase male or female mating fitness.     

No effect of the plant growth regulator, chlormequat, on boar fertility

Chlormequat is a commonly used plant growth regulator in agriculture. Defined levels of chlormequat residue are allowed in food and an acceptable daily intake is defined for humans. However, there are results in the literature suggesting that a daily intake below the acceptable level for human is detrimental for mammalian reproduction. In the present experiment we investigated the effect of chlormequat at levels up to that acceptable for humans on reproduction in male pigs. Chlormequat (also known as chlorocholine chloride (CCC)) was mixed into the diet and given to the experimental animals at three levels (three treatment groups), i.e. 0 mg CCC/kg BW per day (Control), 0.025 mg CCC/kg BW per day and 0.05 mg CCC/kg BW per day. Eight mother sows per treatment group were used in the experiment. From the day of insemination, the mother sows received the experimental diets. The piglets were weaned at 4 weeks of age and two boar littermates continued on the same treatment as the dam until maturity and delivery of semen for in vitro fertilization (IVF) and in vivo fertilization. Semen volume, sperm concentration and fraction of live sperms were not (P 0.46) detrimentally affected by chlormequat intake. The fraction of oocytes developing to more than the one-cell stage at day 5 after IVF was not (P = 0.88) detrimentally affected by chlormequat intake. Chlormequat intake did not detrimentally affect the fraction of gilts being pregnant after one insemination (P = 0.65) or the number of embryos in the pregnant gilts (P = 0.36). Serum chlormequat concentration was 0.9 μg/kg in the 0.025 mg CCC/kg BW per day group and 1.8 μg/kg in the 0.05 mg CCC/kg BW per day group, but was below the detection limit in control animals. In conclusion, the plant growth regulator chlormequat could not be proven to be detrimental to the selected reproduction traits in male pigs. This is in contrast to existing results from the male mouse.     

Developmental flexibility and the effect of social environment on fertility and fecundity in parthenogenetic reproduction

One specialized environment that can influence development arises in the context of social interactions, including the environment contributed by a sexual partner during sexual reproduction. It is often difficult, however, to separate out the effect of mating (fertilization) from the effect of social environment. In the study reported here we examine the effect of social environment mediated by a pheromonal signal on the fertility and fecundity of the facultatively parthenogenetic cockroach Nauphoeta cinerea. By examining parthenogenetically reproducing females, we isolate the effects of social environment in the absence of mating or fertilization. Females exposed to male odors are more likely to produce parthenogenetic offspring. Further, increased exposure to the male pheromone increases the number of offspring produced. Variation in timing of reproduction is also dependent on the male. Thus, social environments are a mechanism by which males contribute to the development of their offspring, resulting in variation in development. This study illustrates the potential evolutionary importance of social environments in development, because a requirement for male-contributed environments may be a constraint to evolving asexual reproduction from a sexually reproducing species.     

The rate of senescence in maternal performance increases with early-life fecundity in red deer

Tradeoffs between reproduction and somatic maintenance are a frequently cited explanation for reproductive senescence in long-lived vertebrates. Between-individual variation in quality makes such tradeoffs difficult to detect and evidence for their presence from wild populations remains scarce. Here, we examine the factors affecting rates of senescence in maternal breeding performance in a natural population of red deer ( Cervus elaphus ), using a mixed model framework to control for between-individual variance. Senescence began at 9 years of age in two maternal performance traits. In both traits, females that produced more offspring in early life had faster rates of senescence. This tradeoff is evident alongside significant effects of individual quality on late life breeding performance. These results present rare evidence in support of the disposable soma and antagonistic pleiotropy theories of senescence from a wild vertebrate population and highlight the utility of mixed models for testing theories of ageing.     

Effects of variations in a formulated protein meal on the fecundity and fertility of female mosquitoes

Abstract. A formulated protein meal developed by Kogan (1990) for adult female Aedes aegypti mosquitoes was evaluated and modified to increase egg and pupal yield. A vigorous laboratory colony was maintained with the females fed exclusively on this dietary formula for about twenty-five generations over more than 2 years. Extra modifications were made to produce a diet suitable for Anopheles arabiensis and Anopheles stephensi females to produce eggs. Both formulations contain bovine albumin, haemoglobin and globulin in a ringer based solution, plus ATP as a phagostimulant for Ae.aegypti. Compared to Kogan's original, our Aedes formula doubled the production of pupae per female after a single meal, although the yield was still significantly lower than from mosquitoes fed on animal hosts or defibrinated pig blood. In varying the proportions of different constituents during attempts to optimize the formula, no relationship was found between total protein content (within the range 80–220 mg/ml) and fecundity, percentage hatch or pupal yield of Ae.aegypti. Equivocal results were found when an isoleucine supplement was added to the formula.     

Effect of radiation on fecundity and fertility of codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) from South Africa

Codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is the key pest of pome fruit in South Africa, and it’s control in apple and pear orchards relies on the application of insecticides and pheromone‐mediated mating disruption. Development of resistance to insecticides and placement of restrictions on the use of certain insecticides has made control of codling moth in South Africa increasingly problematic. The use of the sterile insect technique (SIT) as a control tactic for codling moth is under investigation as a potential addition to the current control strategy. We investigated the radiosensitivity of a laboratory strain of codling moth that was established from moths collected from commercial and organic orchards in the Western Cape, South Africa. Fecundity and fertility of this strain following radiation were consistent with values for the codling moth strain in the Canadian rearing facility in British Columbia. For both strains, the female codling moth was considerably more radiosensitive than the male. At a radiation dose of 100 Gy or higher, treated females were 100% sterile. The fertility of the South African strain was higher (86.3%) than for the Canadian strain (71.9%). This difference in fertility between the two strains was maintained when the dose of radiation was 100 Gy. However, the level of fertility was very similar between the two strains for doses ≥150 Gy. Therefore, based upon previously published work and the data from this study, an operational dose of 150 Gy is recommended for future codling moth SIT programmes in South Africa.     

Effect of diet on the fecundity of three carabid beetles

Abstract In the present study, the importance of diet in terms of fecundity is compared for three species of the carabid genus Amara (Coleoptera: Carabidae), using an insect diet, two types of seed diet (Capsella bursa‐pastoris, Stellaria media) and a mixed diet. It is expected that the species of carabid studied have different food requirements for reproduction. Diet affects reproduction performance and egg production significantly. A mixed diet and both single‐seed diets are suitable for reproduction in Amara aenea (DeGeer) because a higher proportion of the females reproduce and lay significantly more eggs than on a purely insect diet. Females of Amara familiaris (Duftschmid) do not reproduce unless provided with seeds of S. media. Seeds of C. bursa‐pastoris or a mixed diet are equally suitable diets for reproduction of Amara similata (Gyllenhal); a diet of insects or seeds of S. media is unsuitable. The results support the hypothesis that the species under investigation have specific food requirements, suggesting that seed feeding has evolved to different degrees in particular species: A. aenea is omnivorous, whereas A. familiaris and A. similata specialize on the seed of a particular plant species or family. This resource partitioning facilitates co‐occurrence of carabid species.     

A polymorphism within the equine CRISP3 gene is associated with stallion fertility in Hanoverian warmblood horses

Fertility of stallions is of high economic importance, especially for large breeding organisations and studs. Breeding schemes with respect to fertility traits and selection of stallions at an early stage may be improved by including molecular genetic markers associated with traits. The genes coding for equine cysteine-rich secretory proteins (CRISPs) are promising candidate genes because previous studies have shown that CRISPs play a role in the fertilising ability of male animals. We have previously characterised the three equine CRISP genes and identified a non-synonymous polymorphism in the CRISP1 gene. In this study, we report one non-synonymous polymorphism in the CRISP2 gene and four non-synonymous polymorphisms in the CRISP3 gene. All six CRISP polymorphisms were genotyped in 107 Hanoverian breeding stallions. Insemination records of stallions were used to analyse the association between CRISP polymorphisms and fertility traits. Three statistical models were used to evaluate the influence of single mutations, genotypes and haplotypes of the polymorphisms. The CRISP3 AJ459965:c.+622G>A SNP leading to the amino acid substitution E208K was significantly associated with the fertility of stallions. Stallions heterozygous for the CRISP3 c.+622G>A SNP had lower fertility than homozygous stallions (P = 0.0234). The pregnancy rate per cycle in these stallions was estimated to be approximately 7% lower than in stallions homozygous at this position.     

Effect of gossypol on spermatogenesis and fertility in man and mammals

This review summarizes the main results of experimental and clinical studies of a new antifertile agent, gossypol, a polyphenolic compound isolated from the cotton. This compound disturb the normal course of spermatogenesis and affects, first of all, the locomotory system of mature spermatozoa of the man and some mammal species. The mechanism of gossypol action on the development of germ cells is discussed. Since the action of gossypol is reversible and it does not induce strong side effects, the possibility of its application for the control of birth rate is considered.     

Little effect of delayed mating on fecundity or fertility of female fungus gnats Lycoriella ingenua

The effect of delayed female mating for the mushroom fungus gnat Lycoriella ingenua is investigated. We examine the effect of delaying female mating on the fertility and egg viability of female flies that have a mating delay of 0–5 days after emergence. Male fly age is held constant. Female age does not impact male acceptance and most flies copulate within seconds of pairing. We find that female flies experiencing mating delays of 0–4 days after emergence lay a similar number of eggs onto artificial substrates. Females that experience a mating delay of 5 days lay 54% fewer eggs than those that mate on day 0 (day of emergence). There is no effect of mating delay on the percentage of larvae that emerge. The results of the present study indicate that mating delays have little effect on the fertility or fecundity of the mushroom fungus pest L. ingenua.     

Birth seasonally among peasant cultivators: The interrelationship of workload,diet, and fertility

The monthly distribution of live births was analyzed over a 51-year period, 1926–1976, for a rural Taiwan fishing community. Unlike previous studies of birth seasonality, monthly distributions of births did not deviate from what would be expected by chance. This new case is shown to be consistent with the suggestion, developed by Pasternak during a study of birth seasonality in two Taiwan farming communities, that for peasant cultivators the annual cycle of production exerts a more decisive influence on birth seasonality than time of marriage or attributes of temperature, rainfall, or workload. An hypothesis that links the productive cycle to conceptions through the intervening variable of diet is presented and successfully tested using several sets of data on monthly births. A direct effect of nutrition on human fertility, suggested by recent studies of reproductive performance under conditions of nutritional stress, may largely explain seasonality of conceptions and births in populations that experience significant seasonal variation in diet.The Cross Harbor data presented in this paper were collected as part of an ongoing investigation of the comparative demography and social structure of fishing, farming, and market town communities located within a particular Chinese regional system. The support of the National Science Foundation during the period of fieldwork is gratefully acknowledged. I wish to thank G. William Skinner, William H. Durham, Greg Acciaioli, Steven Sangren, Chuang Miao-huei, Harumi Befu, and Philip L. Ritter for their comments on earlier drafts of the present article. I owe a special debt of gratitude to Burton Pasternak (City University of New York), who intellectually inspired and personally encouraged the writing of this paper.     

Effects of Beauveria bassiana and Metarhizium anisopliae on mortality, fecundity and egg fertility of Tetranychus evansi

Abstract:  The susceptibility of various developmental stages of Tetranychus evansi Baker & Pritchard (eggs, larvae, protonymphs, deutonymphs and adults) to the entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin and Beauveria bassiana (Balsamo) Vuillemin was evaluated under laboratory conditions. Three concentrations (3.0 × 10⁶, 1.0 × 10⁷ and 1.0 × 10⁸ conidia/ml) of both fungi were used for each stage. The effect of fungal infection on fecundity and egg fertility was also investigated using both fungal species. Deutonymphs that survived the infection and developed into adult females were allowed to oviposit. Adults and deutonymphs were more susceptible to fungal infection than larval and protonymphal stages at all the concentrations. Nevertheless, the concentration level influenced the mortality of the different mite stages. Eggs were also susceptible to fungal infection and mortality was dose-dependent. Fungus-treated female mites laid fewer eggs than the controls but there was no significant difference in egg hatchability between the treatments.     

土壤肥力对板栗枝干病害的影响

通过对土壤肥力与板栗枝干病害关系的研究表明,在土壤物理因素中,土壤类型以粘土、石砾土的栗园发病较重,壤土、沙壤土、黄棕壤的栗园发病较轻;土壤容重与感病指数呈正相关;土层厚度与感病指数呈负相关。在土壤化学因素中,有机质、速效磷与病情呈负相关;pH值、全氮和钾含量与病情关系不显著,并通过对土壤肥力因素与病情关系的逐步回归分析,筛选出土层厚度、土壤容重、粘性土、有机质和速效磷5个因素对病情贡献较大。以此建立了病情预测的回归模型,根据这一模型,可以预测研究范围内的任一给定条件下病害可能发生的水平,该研究将为今后的板栗生产和管理提供指导。     

The nutritional importance of dietary blood components for reproduction in the tsetse fly, Glossina morsitans

Females of Glossina morsitans morsitans were fed diets of different composition and their performance in terms of survival, fecundity and offspring size, used as a basis for assessing the nutritional importance of the dietary constituents for reproduction. Diets comprised defibrinated bovine blood from which individual components had been removed, or various fractions of bovine blood mixed in different ratios and combinations.Flies fed serum-free diets (comprising saline-washed bovine erythrocytes) failed to reproduce and their ovaries were atrophied. Attempts were made to correct these symptoms by adding serum components to washed erythrocytes. Results showed that serum albumin and lipoproteins were vital for ovarian growth. The erythrocytes in defibrinated bovine blood could be replaced by preparations of haemoglobin. Dialysis against isotonic sodium chloride, removal of gamma globulins, removal of lymphocytes or heating to 55°C for 2 h did not alter the nutritional quality of defibrinated bovine blood. The qualitative importance of dietary albumin associated lipids and lipoproteins for oöcyte growth suggests a specialisation which may be peculiar to viviparous Diptera. Results are discussed in terms of the development of synthetic diets for tsetse.     

类伸展蛋白OsPEX1对水稻花粉育性的影响

类伸展蛋白(Leucine-Rich Repeats Extensins,LRX)是一类细胞壁嵌合蛋白,其N端包含一个LRR(leucine-rich repeats)结构域,C端含Extensins结构域。研究表明,LRX基因家族在拟南芥(Arabidopsis thaliana)花粉萌发和花粉管生长过程中具有重要作用,而水稻(Oryza sativa L.) LRX基因家族是否在调控花粉发育方面具有保守的生物学功能尚不清楚。本研究首先进行了生物信息学分析,结果显示,水稻LRX基因家族包括8个成员,OsPEX3、OsLRX3、OsLRX5位于水稻第1号染色体;OsLRX1、OsLRX3、OsLRX2、OsPEX1和OsPEX2分别位于第2、第5、第6、第11和第12号染色体,其中OsPEX1基因在花粉中高表达,暗示OsPEX1可能参与了花粉发育调控。为此,本研究采用RNAi技术进一步研究了OsPEX1基因对花粉发育的影响。结果表明,OsPEX1基因的RNAi转基因植株花粉败育,结实率仅为10%-30%。qRT-PCR分析显示,这些RNAi转基因植株OsPEX1基因表达量显著低于野生型...     

Effect of Isaria fumosoroseus on mortality and fecundity of Bemisia tabaci and Plutella xylostella

Abstract Entomopathogenic fungi have been used recently for the management of whitefly (Bemisia tabaci) and diamondback moth (Plutella xylostella). In previous studies, Isaria fumosoroseus has shown some potential to control these insect pests. In this paper, the effects of I. fumosoroseus (strain PF01-N4) on the mortality, fecundity and other life table parameters were observed under laboratory conditions. As a first step, the susceptibility of second instars of B. tabaci and P. xylostella was examined in dose-response experiments, which was followed by the studies on the effect of I. fumosoroseus on reproduction. Both B. tabaci and P. xylostella, were susceptible to I. fumosoroseus having median lethal concentration values of 1.10 × 10⁴ and 0.48 × 10⁴ conidia/mL after 12 and 11 days treatment, respectively. The fungal infection significantly reduced the longevity and fecundity of B. tabaci. At 1 × 10⁷ conidia/mL, a minimum average longevity of 9 days was observed as compared to 16.3 days for the control. Similar results were also observed in P. xylostella with an average longevity of 5.6 days as compared to 17.68 days in the control. In case of reproduction, the number of progeny produced by B. tabaci and P. xylostella decreased with an increase in conidial concentration, with the average values of 83.67 and 26.85, 10.92 and 225.51, 112.08 and 31.02 eggs/female for control, 1 × 10⁴ and 1 × 10⁷ conidial/mL, respectively. There was a significant effect of I. fumosoroseus on intrinsic rate of natural increase.