Effects of handling on endocrinology and reproductive performance of the fathead minnow

Anaesthesia with MS-222 followed by intra-peritoneal (ip) injection (with a 10% ethanol in corn oil carrier) of fathead minnow either as one or three (weekly) treatments did not affect survival, behaviour or secondary sexual characteristics of the fish. Fecundity of the fish, as indicated by fertility and hatching success, was also unaffected. Gonadal condition (relative gonad mass, histopathology) was not altered in either sex. Male and female plasma sex steroids (β;-oestradiol, testosterone, 11-ketotestosterone) and male vitellogenin concentrations were not significantly affected by the treatments. Females subjected to either ip treatment regime had significantly higher plasma vitellogenin concentrations than control females. However, based on previous data, this difference did not appear to be treatment-related. Overall, exposure of fathead minnows to chemicals via the ip route should not confound the interpretation of toxicity tests with potential endocrine disrupting chemicals.     

Stem cell-based therapies for fertility preservation in males: Current status and future prospects

With the decline in male fertility in recent years, strategies for male fertility preservation have received increasing attention. In this study, by reviewing current treatments and recent publications, we describe research progress in and the future directions of stem cell-based therapies for male fertility preservation, focusing on the use of spermatogonial stem cells (SSCs), SSC niches, SSC-based testicular organoids, other stem cell types such as mesenchymal stem cells, and stem cell-derived extracellular vesicles. In conclusion, a more comprehensive understanding of the germ cell microenvironment, stem cell-derived extracellular vesicles, and testicular organoids will play an important role in achieving male fertility preservation.     

Reproductive capacity and dominant lethal mutations in female guinea-pigs and Djungarian hamsters following X-rays or chemical mutagens.

The reproductive capacity and induction of dominant lethal mutations in adult female guinea-pigs and Djungarian hamsters were tested following treatment with 400 rad X-rays, 1.6 mg/kg triethylenemelamine (TEM) or 75 mg/kg isopropylmethanesulphonate (IPMS). A fairly high level of dominant lethals were observed in female guinea-pigs mated at the first oestrus after irradiation (23.4 +/- 6.4%) with a lower yield at 3 months (9.6 +/- 8.2%). Neither of the chemicals caused any significant induction of dominant lethals at either mating time. In the reproductive capacity experiments, the mean litter size of irradiated female guinea-pigs was reduced for about 12 months and this was especially marked in the first 6 months following treatment. Neither of the chemicals caused any significant differences in early litter sizes but there was a noticeable reduction in the litter sizes of TEM-treated females in the 18--24 month interval. With Djungarian hamsters a marked effect of X-rays on reproductive capacity was apparent. After 400 rad a smaller proportion of irradiated females littered in the first 25-day interval than after the other treatments, and no irradiated females produced more than one litter. Neither of the chemicals caused such a drastic reduction in fertility but TEM-treated females produced fewer litters and became sterile at an earlier age than control or IPMS-treated females. With IPMS, the number of litters produced was similar to the controls. Both chemicals caused a significant reduction in litter-size but further work is needed to establish whether this was due to induction of dominant lethals. No translocations were observed in the sons of treated female guinea-pigs or hamsters, but the numbers of animals studied were too small for any conclusions to be drawn.     

Lethal and sublethal effects of selected insecticides and an insect growth regulator on the boll weevil (Coleoptera: Curculionidae) ectoparasitoid Catolaccus grandis (Hymenoptera: Pteromalidae)

A laboratory culture of Catolaccus grandis (Burks), an ectoparasitoid of the boll weevil, Anthonomus grandis grandis Boheman, was exposed to lethal and sublethal doses of insecticides and an insect growth regulator using a spray chamber bioassay. Materials tested were azinphos-methyl, endosulfan, fipronil, malathion, cyfluthrin, dimethoate, spinosad, methyl parathion, acephate, oxamyl, and tebufenozide. At full rates, spinosad was significantly less toxic to female C. grandis than other treatments except endosulfan. Fipronil and malathion were significantly more toxic to females than other treatments. Most of the chemicals tested were highly toxic to male C. grandis; spinosad was least toxic. At reduced rates, most of 4 selected chemicals tested were low in toxicity to C. grandis; however, a reduced rate of malathion was significantly more toxic to females than other treatments. No C. grandis pupae developed from parasitism during a 24-h treatment period with malathion or spinosad. The sex ratio of progeny from sprayed adults appeared to be unaffected by the treatments.     

光周期对光敏核不育水稻光敏色素A含量及其mRNA丰度的影响

光敏核不育水稻(农垦58S)是我国特有的水稻(Oryza sativa L.)种质材料,光敏色素是光周期诱导其育性转变的受体。报道了育性转换敏感期间的光周期处理对农垦58S及对照“农垦58”叶片中光敏色素A(Phy A)含量及其mRNA丰度的影响。在10个光周期处理的最后一个暗期结束前,收获每株水稻的上部两片叶,用酶联免疫吸附测定法测定Phy A。和长日照(LD)相比,短日照(SD)处理导致农垦58SPhy A相对含量增加38.5％;而“农垦58”只增加18.5％。显然,在较长的暗期中,农垦58S中Phy A的积累比对照快。在水稻幼苗中也得出相似的结果。以光敏色素A基因(phy A)的特异性片段RPA3作探针,用RNA斑点杂交的方法对叶片中Phy A mRNA丰度进行分析的结果表明,光周期处理5d和10d时,两品种水稻的Phy A mRNA丰度都是SD处理的比LD的高,而且SD下农垦58S Phy A mRNA的丰度均比“农垦58”的高。这些结果表明,甲基化水平较低的农垦58S phy A可能比“农垦58”的phy A更活跃地表达。另外,在育性转换敏感期每日主光期结束时(EOD)进行10次短暂的远红光(FR)照射。结果表明,农垦58S植株抽穗和开花期比SD处理推迟2d,而花粉败育率、种子结实率却无变化。暗示农垦58S开花和育性转变过程的光周期反应可能不同。     

The effects of vinclozolin,an anti-androgenic fungicide,on male guppy secondary sex characters and reproductive success

Despite the enormous volume of research concerning the various effects of chemicals with endocrine-disrupting properties in fish, there is still very little evidence that endocrine disruption can adversely affect individual fertility and, hence, pose problems for the population. In the present study, guppies (Poecilia reticulata) were fed with the anti-androgenic fungicide vinclozolin at concentrations ranging from 1.8 to 180 mg/kg from 8-14 wk of age. Male sperm count and the intensity of his sexual display behavior were significantly reduced in treatment groups, which was in line with the results of previous studies. Here, we show further that these impairments translate into reduced fertility, measured as the size of the female's first clutch. Also, this reduced fertility was correlated to the male sperm count, but not to the intensity of the male sexual display. Finally, by crossing exposed with unexposed animals, we show that the adverse effect of vinclozolin on reproduction is mediated through the male alone.     

Effect of Photoperiod Treatments on Phytochrome a Levels and Its mRNA Abundance in Photoperiod-Sensitive Genic Male-Sterile Rice Mutant and the Wild Type

The effect of photoperiod treatments on phytochrome A (Phy A) level and its mRNA abundance in the leaves of a photoperiod-sensitive genic male-sterile mutant (Nongken 58S) and its wild type ("Nongken 58') of Oryza sativa L. was investigated. The top two leaves of each rice shoot were harvested at the end of the last dark phase of 10 cycles during photoperiod-sensitive stage for fertility alteration of the mutant. Phy A was measured by a sandwich enzyme-linked immunosorbent assay (ELISA) using rabbit polyclonal and mouse monoclonal antibodies. Compared with longday (LD) treatment,short day (SD) resulted in 38.5% increase of relative Phy A content in the mutant, only 18.5% increase in the wild type. In an extended darkness (25 h), the accumulation of Phy A also appeared to be more rapid in the mutant seedlings than in its wild type. RNA dot blot analyses with RPA3 (a cDNA clone of rice Phy A) as a probe showed:the abundances of Phy A mRNA in top leaves of Nongken 58S and "Nongken 58" were obviously higher in SD than those in ID at the end of dark phase of 5 d and 10 d photoperiod treatments. Moreover, under SD Phy A mRNA contents in Nongken 58S were more than those in "Nongken 58" during the whole photoperi- od-sensitive stage for fertility alteration. In addition, after 10 cycles of end-of-day far-red irradiations (EOD FR), the heading and flowering date of the mutant was delayed for 2 d. However, EOD FR had little or no effect on male fertility of the mutant.     

Cuelure but not zingerone make the sex pheromone of male Bactrocera tryoni (Tephritidae: Diptera) more attractive to females

In tephritid fruit flies of the genus Bactrocera Macquart, a group of plant derived compounds (sensu amplo ‘male lures’) enhance the mating success of males that have consumed them. For flies responding to the male lure methyl eugenol, this is due to the accumulation of chemicals derived from the male lure in the male rectal gland (site of pheromone synthesis) and the subsequent release of an attractive pheromone. Cuelure, raspberry ketone and zingerone are a second, related group of male lures to which many Bactrocera species respond. Raspberry ketone and cuelure are both known to accumulate in the rectal gland of males as raspberry ketone, but it is not known if the emitted male pheromone is subsequently altered in complexity or is more attractive to females. Using Bactrocera tryoni as our test insect, and cuelure and zingerone as our test chemicals, we assess: (i) lure accumulation in the rectal gland; (ii) if the lures are released exclusively in association with the male pheromone; and (iii) if the pheromone of lure-fed males is more attractive to females than the pheromone of lure-unfed males. As previously documented, we found cuelure was stored in its hydroxyl form of raspberry ketone, while zingerone was stored largely in an unaltered state. Small but consistent amounts of raspberry ketone and β-(4-hydroxy-3-methoxyphenyl)-propionic acid were also detected in zingerone-fed flies. Males released the ingested lures or their analogues, along with endogenous pheromone chemicals, only during the dusk courtship period. More females responded to squashed rectal glands extracted from flies fed on cuelure than to glands from control flies, while more females responded to the pheromone of calling cuelure-fed males than to control males. The response to zingerone treatments in both cases was not different from the control. The results show that male B. tryoni release ingested lures as part of their pheromone blend and, at least for cuelure, this attracts more females.     

粗厚山羊草（Ae.crassa）细胞质普通小麦核代换系在中国不同光温条件地点的雄性育性变异

5个普通小麦品系的粗厚山羊草4X,6X种细胞质的7个核代换系在中国昆明,元谋,杨陵,互助,依安5个不同纬度地点种植的自交结实率,结合各点光温条件的分析表明,粗厚山羊草细胞质普通小麦核代换系的雄性育性随日长增加而下降,6X种细胞质核代换系在日长≥14.28h开始出现完全雄性不育,4X种细胞质核代换系在日长≥15.38h开始出现完全雄性不育;该细胞质核代换系的雄性育性在日长因子主控下,对温度变化也表现一定敏感性。粗厚山羊草细胞质背景下不同核基因型对光,温条件的敏感性有显著差异。核质互作效应是这种敏感性的遗传方式,粗厚山羊草4X、6X种细胞质的光,温敏感性存在差异。6X种细胞质的光,温敏感性高于4X种细胞质。     

Long-term effects of accelerated or delayed sexual maturation on reproductive output in wild female house mice (Mus musculus)

The effects of acceleration and delay of puberty in female house mice on survival and reproduction were tested using 6 experimental groups: (1) control females mated at the time of first oestrus, (2) females mated at weaning, (3) females treated with male urine starting at weaning and mated at first oestrus, (4) females housed in groups and mated at first oestrus, (5) females housed alone, treated with urine from grouped females and mated at first oestrus, and (6) females housed alone and mated at 68 days of age. Females caged with males at weaning or treated with male urine and mated at puberty had lower rates of survival to 180 days of age, but did not differ in rates of fertility from mice in the other four treatments. Those females that were housed with males from weaning or treated with male urine also had smaller total numbers of litters, fewer total young, and smaller average litter sizes than did females for which the age of mating was delayed, by grouping or treatment with urine from grouped females, or by being held until age 68 days before mating. Control females mated at first oestrus generally were intermediate or did not differ from the male treatments on these dependent variables. There were no differences in the average number of female young/litter across the 6 treatments. However, females that were delayed in age of first mating had significantly more male young/litter than did females that were accelerated in their sexual development or control females.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of mutagenicity induced by MMS and DES in Capsicum annuum L.

Seeds of Capsicum annuum L. var. G4 were subjected to different concentrations of methyl methane sulphonate (MMS) and diethyl sulphate (DES). The effects of different mutagenic treatments on meiosis, chiasma frequency, and pollen fertility have been studied in M₁ generation. Various types of meiotic aberrations such as univalent, multivalent, stickiness, bridge, laggards, cytomixis etc. were observed in all the treatments. However, the MMS treatments proved to be more effective in inducing meiotic aberrations as compared to DES. Moreover, the frequency of meiotic aberrations was at its maximum at metaphase followed by anaphase and telophase stages. As the concentrations increase, reduction in chiasma frequency and pollen fertility was observed in all the treatments and, MMS again was found to be more effective than DES treatments.     

不同水肥和光照条件对水稻化感特性的影响

采用盆栽实验对水稻化感品种华航1号在不同水肥和光照条件下的化感潜力和化感物质进行了研究。结果表明,华航1号在较高水肥条件下化感潜力较强,而在较低水肥条件下化感潜力下降,进一步对华航1号的化感特征物质的含量测定表明,在较低水肥条件下其化感物质没有显著的变化,只是次生物质的种类有所增加,尤其是一些具有抗病功能的次生物质的含量有所增加,在弱光照条件下华航1号的化感特征物质含量比在较强光照条件下要低,而且具有抗病功能的次生物质含量则保持较高水平,结果还发现,不论水、肥或光照条件的变化,华航1号对非伴生杂草的化感潜力都比伴生杂草要强。     

Protection of Wheat Seedlings from Helminthosporium Infection by Seed Treatment with Chemicals

Twenty of twenty-four chemicals known to induce phytoalexin production in other plants, when used to soak seed, provided effective protection to 3-week-old susceptible wheat seedlings against inoculation with Helminthosporium sativum. The number of lesions was very significantly reduced in most of these treatments and there was evidence for inhibition of lesion expansion in a few. Studies with twelve of the more effective chemicals showed that the protective effect persisted at significant levels even in 5-week-old plants and that at this stage the inhibitory effect on lesion expansion was more pronounced in most of the treatments. Different treatments led to the development of a moderate to high level of fungitoxicity in young wheat seedlings which gradually declined with age of the plant and disappeared in 5-week-old plants. When inoculated at the age of 3 or 5 weeks, plants receiving most of the treatments developed appreciably higher fungitoxicity than the untreated plants.     

Clinal variation in post‐winter male fertility retention; an adaptive overwintering strategy in Drosophila melanogaster

In insects including Drosophila melanogaster, females can overwinter at the adult stage by adopting a shallow reproductive diapause, but almost nothing is known about male reproductive diapause. In this study, we test for the maintenance of fertility in overwintering males from the eastern Australian D. melanogaster cline. Males from southern temperate populations maintained in field cages in temperate Melbourne had a higher fertility in spring compared with males from tropical locations. Temperate males successfully inseminated more females, and there were also more offspring produced per inseminated female. The resulting linear post‐winter fertility clines were unrelated to male body size. In contrast, there was no clinal variation for fertility in nonoverwintering males held in the laboratory. The cline in overwintering male fertility is likely to have evolved as an adaptive response to latitudinal climatic variation over the last 100 years.     

Resource availability dominates and alters the relationship between species diversity and ecosystem productivity in experimental plant communities

Experimental evidence that plant species diversity has positive effects on biomass production appears to conflict with correlations of species diversity and standing biomass in natural communities. This may be due to the confounding effects of a third variable, resource availability, which has strong control over both diversity and productivity in natural systems and may conceal any positive effects of diversity on productivity. To test this hypothesis, I independently manipulated resource availability (soil fertility) and sown species diversity in a field experiment and measured their individual and interactive effects on productivity. Although fertility was a far stronger predictor of productivity than diversity, the effect of diversity on productivity significantly increased with fertility. Relative yield analyses indicated that plant mixtures of high fertility treatments significantly "overyielded," or were more productive than expected based on monoculture yields of component species. In contrast, plant mixtures of low fertility treatments had significantly lower-than-expected yields. The effect of diversity on productivity was also driven by sampling effects, where more species-rich mixtures were more likely to include particularly productive species. Unexpectedly, the strength of sampling effects was largely insensitive to fertility, although the particular species most responsible for sampling effects did change with fertility. These results suggest that positive effects of species diversity on ecosystem productivity in natural systems are likely to be masked by variation in environmental factors among habitats.     

Fertility and the aging male

In the United States since 1980, the birth rate in women aged > 35 years has increased by nearly 60%, whereas the birth rate for women aged 20 to 34 years has increased by only 10%. The trend in parenthood at an older age has also been seen in men. Since 1980, the fertility rate for men in their 30s has increased by 21% and for men aged 40 years and older, the rate has increased nearly 30%. In contrast, the fertility rate in men younger than age 30 years has decreased by 15%. Age-related infertility will continue to be a problem. A basic understanding of the issues is critical for health care professionals so that they can effectively counsel patients who are considering a delay in childbearing for social reasons or for those seeking fertility treatments. This review details the changes in fertility seen in the aging male.     

The multigenerational effects of water contamination and endocrine disrupting chemicals on the fitness of Drosophila melanogaster

Water pollution due to human activities produces sedimentation, excessive nutrients, and toxic chemicals, and this, in turn, has an effect on the normal endocrine functioning of living beings. Overall, water pollution may affect some components of the fitness of organisms (e.g., developmental time and fertility). Some toxic compounds found in polluted waters are known as endocrine disruptors (ED), and among these are nonhalogenated phenolic chemicals such as bisphenol A and nonylphenol. To evaluate the effect of nonhalogenated phenolic chemicals on the endocrine system, we subjected two generations (F0 and F1) of Drosophila melanogaster to different concentrations of ED. Specifically, treatments involved wastewater, which had the highest level of ED (bisphenol A and nonylphenol) and treated wastewater from a constructed Heliconia psittacorum wetland with horizontal subsurface water flow (He); the treated wastewater was the treatment with the lowest level of ED. We evaluated the development time from egg to pupa and from pupa to adult as well as fertility. The results show that for individuals exposed to treated wastewater, the developmental time from egg to pupae was shorter in individuals of the F1 generation than in the F0 generation. Additionally, the time from pupae to adult was longer for flies growing in the H. psittacorum treated wastewater. Furthermore, fertility was lower in the F1 generation than in the F0 generation. Although different concentrations of bisphenol A and nonylphenol had no significant effect on the components of fitness of D. melanogaster (developmental time and fertility), there was a trend across generations, likely as a result of selection imposed on the flies. It is possible that the flies developed different strategies to avoid the effects of the various environmental stressors.     

农用化学品污染及预防建议

农用化学品是农业生产的重要组成部分,其安全问题也成为人们关注的焦点。农用化学品可分为化肥、农药、农膜3类。化肥主要用于提高土壤肥力,增加农作物产量,不合理使用则会改变土壤性质,降低土壤肥力,并且对生态环境以及人类健康造成不可忽视的危害。农药主要用于杀菌、杀虫、除草等,在促进和保障农作物健康生长中发挥重要作用,但农药的滥用造成农药事故频发,农药的毒性富集作用以及残留问题越发引起人们的关注。农膜主要用于农膜覆盖栽培技术,农膜的原料主要是聚乙烯树脂等高分子化学物质,在土壤中很难降解,造成的环境污染问题日益突出。各种农用化学品的不合理使用,可降低农产品的质量,使其在出口贸易中受到极大限制,造成巨大的经济损失。本文在肯定农用化学品在现代化农业生产中的巨大贡献的同时,深入分析了其污染状况及危害,总结了当前国际上对于化肥、农药、农膜的研究进展以及所取得的成果,最后提出了科学使用农用化学品的建议。     

Superovulatory response, embryo quality and fertility after treatment with different gonadotrophins in native cattle

We studied native Mertolengo cattle to evaluate superovulatory (SOV) treatments, subsequent fertility of donors and pregnancy rate of recovered embryos. In Experiment 1 we compared superovulatory response (SR), embryo quality and plasma progesterone (P4) levels between donors treated with eCG (10 cows and 5 heifers) vs. FSH (pure, FSH-1, n=10 cows and crude, FSH-2, n=10 cows), during progestagenic impregnation. We also compared fertilization rates and embryo quality of bred and inseminated eCG and FSH-1 donors. Significantly more viable embryos were yielded by FSH than by eCG treated donors. Less FSH-1 than FSH-2-treated donors showed SR, but the response was identical in responder donors of both groups. Fertilization rates were significantly higher in bred than in inseminated donors. Plasma P4 levels were only significantly different (higher) between responder and non-responder donors on the day of embryo recovery. Experiment 2 compared FSH treatments (FSH-2, crude, n=11 cows and FSH-3, pure, n=10 cows) started at the midluteal phase. The mean number of viable embryos was significantly higher in FSH-3 than in FSH-2 treated donors. Both FSH treatments exerted a similar luteotrophic effect upon injection. The FSH-2 donors treated during the midluteal phase yielded more ova and showed significantly higher plasma P4 levels at all sampling days than those treated during progestagenic impregnation. The pregnancy rates of recipient cows were 67% and 46% for fresh and frozen-thawed embryos respectively. In Experiment 3, the fertility of donors (n=20) after SOV treatments was compared with that of untreated cows (n=40). Time to conception of donors, after mating with a bull 14 days after embryo recovery, was identical to that of control cows. There was some delay to conception in eCG-treated cows, but the difference was not significant. These preliminary results suggest that response to SOV treatments in Mertolengo cattle might be affected by the type of gonadotrophin and by the treatment protocol. The fertility of a traditional breeding season after SOV treatments was not impaired. Cryopreserved embryo banking can be used to preserve the breed.     

Fecundity and fertility reductions in adult leafrollers exposed to surfaces treated with the ecdysteroid agonists tebufenozide and methoxyfenozide

The effects on the fecundity and fertility of redbanded leafroller, Argyrotaenia velutinana (Walker), and obliquebanded leafroller,Choristoneura rosaceana (Harris), exposed as adults to surfaces treated with the ecdysone agonists tebufenozide (RH-5992) and methoxyfenozide (RH-2485) were examined. The first part of the study consisted of recently emerged moths being exposed to treated surfaces continuously throughout their lives (including mating and oviposition). Continuous exposure to tebufenozide- or methoxyfenozide-treated surfaces significantly reduced the mean number of eggs laid and the percent of eggs that hatched in both species. The second part of the study involved exposure of recently emerged virgin moths (by sex) to treated surfaces for 24 h, after which, the exposed moths were paired with a nontreated partner to mate and oviposit on nontreated surfaces. In this experiment, for A. velutinana, significant reductions in fecundity occurred only when the female was exposed to methoxyfenozide-treated surfaces. Significant reductions in A. velutinana egg fertility occurred with both male and female exposure in the methoxyfenozide treatments and only female exposure in the tebufenozide treatments. For C. rosaceana, significant reductions in fecundity occurred with both male and female exposure in the tebufenozide and methoxyfenozide treatments. Significant reductions in C. rosaceana egg fertility occurred with both male and female exposure in the tebufenozide treatments and only with female exposure in the methoxyfenozide treatments.