Reproductive hacking: A male seminal protein acts through intact reproductive pathways in female Drosophila

Seminal proteins are critical for reproductive success in all animals that have been studied. Although seminal proteins have been identified in many taxa, and female reproductive responses to receipt of these proteins have been documented in several, little is understood about the mechanisms by which seminal proteins affect female reproductive physiology. To explore this topic, we investigated how a Drosophila seminal protein, ovulin, increases ovulation rate in mated females. Ovulation is a relatively simple physiological process, with known female regulators: previous studies have shown that ovulation rate is promoted by the neuromodulator octopamine (OA) in D. melanogaster and other insects. We found that ovulin stimulates ovulation by increasing OA signaling in the female. This finding supports a model in which a male seminal protein acts through “hacking” a well-conserved, regulatory system females use to adjust reproductive output, rather than acting downstream of female mechanisms of control or in parallel pathways altogether. We also discuss similarities between 2 forms of intersexual control of behavior through chemical communication: seminal proteins and pheromones.     

In vitro fertilization analysis of squirrel monkey oocytes produced by various follicular induction regimens and the incidence of triploidy

An in vitro fertilization system utilizing squirrel monkeys was used to compare follicle-stimulating hormone, clomiphene citrate and prostaglandin E₁ as follicular induction regimens, analyze culture medium characteristics, and examine the physiological phenomenon of polyspermy. Induction of follicular growth was poor with clomiphene citrate when compared to the control group and increased the incidence of atretic follicles at all levels tested. When prostaglandin E₁ was administered, larger numbers of mature oocytes were recovered at laparoscopy. There was no difference in fertilization rate between the treatment and control groups. Homologous serum was an adequate protein source in TC-199 fertilization medium for squirrel monkey oocytes. Although the rate of triploidy was increased with in vitro fertilization, there was no relationship between sperm concentration and the incidence of polyspermy. These findings demonstrate that the squirrel monkey is a valuable primate system for studies of in vitro fertilization and preimplantation development. © 1993 Wiley-Liss, Inc.     

Adaptive diversity in genetic control of egg-laying behavior in Drosophila melanogaster

Summary

In the absence of insemination or of a suitable oviposition site, Drosophila melanogaster females react with egg retention patterns which differ as to the position in the genital tract at which the mechanism operates (ovarioles for initial retention; uterus for oviposition blocking) and to physiological basis. A study of the first laboratory generation of isofemale lines, founded by using three different samples of wild flies collected the same year from a natural population, showed a significant genetic variability in initial egg retention by virgin females and in the capacity for oviposition blocking by mated flies reacting to an unfavorable oviposition site. Comparison of isofemale lines showed that these two adaptive behavior patterns also differ in their genetic determination. They are controlled, and therefore can react, independently to selection pressures resulting from seasonal variation in the natural environment.     

Genetic Control of Biogenic-Amine Systems in Drosophila Under Normal and Stress Conditions

The contents of octopamine and its precursors (tyrosine and tyramine) were studied in adults of two lines of Drosophila virilis with contrasting stress responses. It was demonstrated that in individuals responding to stress by a hormonal stress reaction (line 101), the contents of octopamine and tyrosine are lower than in nonresponding flies (line 147). It was found that there is no difference between the lines in the level of tyramine under normal conditions. The dopamine response to stressor was also studied. Genetic analysis of these differences revealed that they are controlled by a single gene and that the gene is not sex-linked. The gene controlling the response was found to be linked to chromosome 6 of D. virilis.     

Tyrosine Decarboxylase and Dopa Decarboxylase in Drosophila virilis Under Normal Conditions and Heat Stress: Genetic and Physiological Aspects

The activity of tyrosine decarboxylase (TDC) and dopa decarboxylase (DDC) was studied in adults of two lines of Drosophila virilis,contrasting in their reaction to stress conditions. Differences were found in the activity of both enzymes between individuals of the examined lines. Genetic analysis of these differences was made. Each of the two enzymes was found to be controlled by a single gene or, possibly, by a block of closely linked genes. The gene responsible for TDC activity is located on one of the autosomes (excluding chromosome II). DDC activity in D. virilisis regulated by a gene located, apparently, on chromosome II. Adults of the line responding to stress by a stress reaction (r-line) were shown to react to a short-term heat stress (38°C, 60 min) by a decrease in TDC activity. TDC activity in flies of the line incapable of the stress reaction (nr-line) did not alter in such conditions. DDC activity of adults of both lines was found to be unchangeable under stress conditions.     

Identification and characterization of a novel family of Drosophila beta-adrenergic-like octopamine G-protein coupled receptors

Insect octopamine receptors carry out many functional roles traditionally associated with vertebrate adrenergic receptors. These include control of carbohydrate metabolism, modulation of muscular tension, modulation of sensory inputs and modulation of memory and learning. The activation of octopamine receptors mediating many of these actions leads to increases in the levels of cyclic AMP. However, to date none of the insect octopamine receptors that have been cloned have been convincingly shown to be capable of directly mediating selective and significant increases in cyclic AMP levels. Here we report on the identification and characterization of a novel, neuronally expressed family of three Drosophila G-protein coupled receptors that are selectively coupled to increases in intracellular cyclic AMP levels by octopamine. This group of receptors, DmOct beta1R (CG6919), DmOct beta2R (CG6989) and DmOct beta3R (CG7078) shows homology to vertebrate beta-adrenergic receptors. When expressed in Chinese hamster ovary cells all three receptors show a strong preference for octopamine over tyramine for the accumulation of cyclic AMP but show unique pharmacological profiles when tested with a range of synthetic agonists and antagonists. Thus, the pharmacological profile of individual insect tissue responses to octopamine might vary with the combination and the degree of expression of the individual octopamine receptors present.     

Spontaneous and sperm-induced activation of oocytes in LT/Sv strain mice

The oocytes of LT/Sv strain mice are unique in that a high proportion of them (∼40% in this study) are ovulated before reaching metaphase of the second meiotic division (metaphase II). The remaining oocytes of LT/Sv mice are ovulated at metaphase II, as in other strains of mice. When recently ovulated oocytes were cultured in vitro for 11–12 h, those ovulated at metaphase II remained at this stage, whereas those ovulated at metaphase of the first meiotic division (metaphase I) commonly resumed meiosis during in vitro aging. These oocytes extrude the polar body and form a diploid pronucleus. This oocyte activation is not coupled with cortical granule exocytosis. The oocytes ovulated at metaphase II are fully capable of normal fertilization, whereas those ovulated at metaphase I are not. Approximately 50% of metaphase I oocytes penetrated by spermatozoa remain at this stage, and sperm nuclei frequently undergo premature chromosome condensation. Only 13% of spermpenetrated metaphase I oocytes formed a diploid female pronucleus and a haploid male pronucleus by 4 h after insemination. These results demonstrate that the two types of ovulated LT/Sv oocytes have different potentials to undergo either spontaneous or sperm-induced activation.     

基础卵泡刺激素水平对IVF/ICSI-ET超排卵周期卵巢反应

目的：基础卵泡刺激素(bFSH)可以刺激精子生成和促进卵子成熟,是人体内重要的激素之一。本研究针对体外受精(IVF)周期bFSH 水平的变化情况,探讨bFSH对卵巢反应的预测价值,为临床研究提供理论基础。方法：回顾性分析2012 年1 月-2012 年12 月在我院生殖医学中心接受体外受精- 胚胎移植(IVF-ET)治疗的154例患者的临床资料,根据基础卵泡刺激素水平分为A 组(bFSH≥10 IU/L)、B 组(8≤bFSH≤10 IU/L)和C 组(bFSH<8 IU/L)。对比分析三组对象的年龄、基础窦卵泡数(bAFC)、黄体生成素(LH)含量、FSH/LH 值、促性腺激素(Gn)的用量、使用时间、受精率及临床妊娠率等。结果：三组患者的年龄、bAFC 及FSH/LH相比较,差异具有统计学意义(P<0.05);三组的Gn 用量和时间、获卵数及妊娠率比较,差异显著且具有统计学意义(P<0.05);三组基础LH 值及超排卵周期受精率无显著差异(P>0.05)。结论：基础卵泡刺激素(bFSH)对体外受精女性的卵巢储备功能具有一定的预测价值,bFSH 水平的高低可作为预测女性不孕患者超排卵周期卵巢反应性的一项重要指标,值得临床推广和应用。     

基础窦卵泡数对IVF/ICSI-ET超排卵周期卵巢反应的预测价值*

摘要目的：窦卵是女性宫腔内的泡状细胞,与女性卵巢的发育及功能密切相关。本研究针对体外受精(IVF)周期中基础窦卵泡数(antral follicle count, AFC)的变化情况,探讨AFC 对卵巢反应的预测价值,为临床研究提供理论基础。方法：回顾性分析2012 年1月至2012 年12 月在我院生殖医学中心接受体外受精- 胚胎移植的157 例患者的临床资料,根据基础窦卵泡数将所选病例分为A 组(bAFC逸10)和B组(bAFC＜10)。对比并分析两组研究对象的促性腺激素(Gn)的用量及使用时间、获卵数、人绒毛膜促性腺激素(HCG)注射日的血清中雌激素(E2)水平、受精率、临床妊娠率等。结果：A 组患者的Gn 用量、HCG日E2 值、获卵数及临床妊娠率均显著高于B 组,差异具有统计学意义(P<0.05);两组患者的年龄和基础卵泡刺激素水平差异显著且具有统计学意义(P<0.05);两组患者的不孕原因、不孕年限及助孕方式无明显差异(P>0.05)。结论：基础窦卵泡对体外受精女性促排卵周期的卵巢反应及助孕结局具有一定的预测价值,其数量的多少可作为促排卵过程中评价卵巢反应性的参考指标,应在临床进一步推广。     

The Histone H3K9 Demethylase Kdm3b Is Required for Somatic Growth and Female Reproductive Function

Kdm3b is a Jumonji C domain-containing protein that demethylates mono- and di-methylated lysine 9 of histone H3 (H3K9me1 and H3K9me2). Although the enzyme activity of Kdm3b is well characterized in vitro, its genetic and physiological function remains unknown. Herein, we generated Kdm3b knockout (Kdm3bKO) mice and observed restricted postnatal growth and female infertility in these mice. We found that Kdm3b ablation decreased IGFBP-3 expressed in the kidney by 53% and significantly reduced IGFBP-3 in the blood, which caused an accelerated degradation of IGF-1 and a 36% decrease in circulating IGF-1 concentration. We also found Kdm3b was highly expressed in the female reproductive organs including ovary, oviduct and uterus. Knockout of Kdm3b in female mice caused irregular estrous cycles, decreased 45% of the ovulation capability and 47% of the fertilization rate, and reduced 44% of the uterine decidual response, which were accompanied with a more than 50% decrease in the circulating levels of the 17beta-estradiol. Importantly, these female reproductive phenotypes were associated with significantly increased levels of H3K9me1/2/3 in the ovary and uterus. These results demonstrate that Kdm3b-mediated H3K9 demethylation plays essential roles in maintenance of the circulating IGF-1, postnatal somatic growth, circulating 17beta-estradiol, and female reproductive function.     

基础卵泡刺激素水平对IVF／ICSI—ET超排卵周期卵巢反应的预测价值

目的：基础卵泡刺激素（bFsH）可以刺激精子生成和促进卵子成熟,是人体内重要的激素之一。本研究针对体外受精（IVF）周期bFSH水平的变化情况,探讨bFSH对卵巢反应的预测价值,为临床研究提供理论基础。方法：回顾性分析2012年1月-2012年12月在我院生殖医学中心接受体外受精．胚胎移植（IVF—ET）治疗的154例患者的临床资料,根据基础卵泡刺激素水平分为A组CoFSH≥10IU／L）、B组（8≤bFsH≤10IU／L）和c组（bFSH〈8IU／L）。对比分析三组对象的年龄、基础窦卵泡数（bAFC）、黄体生成素（LH）含量、FSH／LH值、促性腺激素（Gn）的用量、使用时间、受精率及临床妊娠率等。结果：三组患者的年龄、bAFC及FSH／LH相比较,差异具有统计学意义（P〈0．05）;三组的Gn用量和时间、获卵数及妊娠率比较,差异显著且具有统计学意义（P〈0．05）;三组基础LH值及超排卵周期受精率无显著差异（P〉0．05）。结论：基础卵泡刺激素（bFSH）对体外受精女性的卵巢储备功能具有一定的预测价值,bFSH水平的高低可作为预测女性不孕患者超排卵周期卵巢反应性的一项重要指标,值得临床推广和应用。