A sex-specific test of selection in utero

We find support for the hypothesis that changes in the monthly odds of a twin among live-born males predict subsequent and opposite changes in the odds of a twin among live-born females. The hypothesis arises from the long standing argument that natural selection has conserved mechanisms by which pregnant women in stressed populations spontaneously abort fetuses least likely to yield grandchildren. Previous attempts to empirically test this argument focus almost entirely on males. We contribute to the literature by showing that, consistent with the logic of natural selection, maternal adaptations to environmental changes likely have effects on the survival of both male and female conceptuses and fetuses.     

Successful low dose insemination of flow cytometrically sorted Sika (Cervus nippon) sperm in Wapiti (Cervus elaphus)

The purpose of this study was to determine a practical method in Wapiti (Cervus elaphus) of using predetermined sexed Sika (Cervus nippon) semen. Semen was collected by electro-ejaculation from one stag of proven fertility and transported to the laboratory where it was retained as unsorted (control) or was separated into X- and Y-chromosome-bearing sperm using a modified high-speed cell sorter. Wapiti hinds (n = 81) were inseminated into the uterus by rectum manipulation with 1 × 10⁶ (X1 and Y1 group, respectively) or 2 × 10⁶ (X2 and Y2 group, respectively) of sorted frozen-thawed and 1 × 10⁷ non-sorted frozen-thawed (a commercial dose control) Sika motile sperm 60–66 h after removal of intra-vaginal progesterone-impregnated CIDR devices and administration of 700 IU of PMSG at the time of CIDR removal. The percentage of hinds calving after insemination was similar for X1 (38.5%), X2 (41.7%), Y1 (44.4%), Y2 (38.9%) groups (P > 0.05), but higher for control (75%) treatment (P < 0.05). Ultimately 15 out of the 16 Sika and Wapiti-hybrid calves produced by Wapiti hinds inseminated with Y-sorted sperm were male (93.7%) and 10/10 (100%) Sika and Wapiti-hybrid calves from hinds inseminated with X-sorted sperm were female. The sex ratio of the Sika and Wapiti-hybrid calves born to hinds inseminated with sex-sorted sperm deviated significantly (P < 0.05) from 50% and 50.0% in the control group. All Sika and Wapiti-hybrid calves were born between 237 and 250 d of gestation. Male and female calves in the control group had similar birth weights and weaning weights as calves from hinds inseminated with X- or Y-sorted sperm. In conclusion it can be said that normal Sika and Wapiti-hybrid calves of predicted sex can be produced after artificial insemination of Wapiti does with low numbers of sex-sorted cryopreserved Sika sperm.     

The GnRH antagonist acyline prevented ovulation, but did not affect ovarian follicular development or gestational corpora lutea in the domestic cat

Two experiments were conducted to investigate the effects of the GnRH antagonist acyline (330 μg/kg, given sc) on ovarian follicular development and ovulation, as well as on pregnancy maintenance in domestic cats. In the first experiment, seven queens in proestrus (total of 24 proestrus periods), were randomly assigned to treatment with either acyline (ACY; n = 17) or a placebo (PLC; n = 7). All queens were mated with a fertile tomcat. In the ACY and PLC groups, cessation of estrus occurred (mean ± SEM) 7.0 ± 1.3 and 7.0 ± 1.7 d after treatment (P > 0.1), ovulation occurred in 2 of 17 and all seven estrus periods (P < 0.05), and pregnancy rates were 1 of 16 and 7 of 7 (P < 0.05), respectively. In the ACY and PLC groups, intervals from treatment to the onset of the ensuing proestrus were 18.4 ± 1.7 and 120 ± 17.2 d. In the second experiment, 14 pregnant queens were randomly allocated, according to their mating date, to treatment with acyline in early pregnancy (from 20 to 25 d, n = 3), mid pregnancy (from 26 to 45 d; n = 4), late pregnancy (> 45 d; n = 3), or injection of a placebo in early (n = 1), mid (n = 2), or late pregnancy (n = 1). Ultrasonographic assessments of the uterus were done every second day for 2 wk post treatment, and serum progesterone (P₄) concentrations were determined before treatment, and at 7 and 14 d after treatment. No pregnancies were prematurely terminated and post-treatment P₄ concentrations did not differ among treatment groups (P > 0.1). In conclusion, in the domestic cat, GnRH withdrawal by acyline prevented ovulation when given in early follicular phase (proestrus), but did not significantly affect luteal function during pregnancy.     

Phosphodiesterase inhibitor 3-isobutyl-methyl-xanthine stimulates reproduction in rabbit females

The aim of our study was to examine the influence of 3-isobutyl-1-methyl-xanthine (IBMX), an inhibitor of cyclic adenosine monophosphate and cyclic guanosine monophosphate phosphodiesterases, on the reproductive efficiency of gonadotropin-stimulated rabbits (Oryctolagus cuniculus, Leporidae, Lagomorpha). The ovarian cycle and ovulation of control rabbits was induced by pregnant mare serum gonadotropin (PMSG) followed by administration of human chorionic gonadotropin (hCG; first series of experiments) or gonadotropin-releasing hormone (GnRH; second series of experiments). Experimental animals received PMSG and hCG together with IBMX (at 5 or 25 μg/animal) or GnRH together with IBMX (at 50 or 500 μg/animal). After ovulation and mating, in the first series of experiments, animals were killed; the pronuclear-stage eggs were flushed from the oviducts and cultured up to blastocyst cell stage. Numbers of ovarian corpora lutea, ovulated oocytes, and oocyte-derived embryos reaching blastocyst stage were determined. In the second series of experiments, all the animals were kept until parturition, when the pregnancy and birth rate, litter size, and number, viability, and body weight of pups were recorded. IBMX injections at doses of 5 or 25 μg/animal significantly increased the number of ovulations/corpora lutea, harvested zygotes, and embryos derived from these zygotes. Administration of IBMX at doses of 500 μg/animal or 50 μg/animal to nulliparous young animals (4.5 mo of age) significantly increased their pregnancy rate and birth rate, litter size, and litter weight. In multiparous old animals (2 yr of age), IBMX at a dose of 50 μg/animal, but not 500 μg/animal, significantly increased their pregnancy rate and litter size, but not the birth rate, number of pups per female, or litter weight. These data demonstrate that (1) IBMX can enhance the stimulatory effect of GnRH/gonadotropins on rabbit ovulation, oocyte maturation, embryo yield and development, pregnancy and birth rate, and number, viability, and body weight of pups; (2) nulliparous young females (4.5 mo of age) are more sensitive to IBMX treatments than the multiparous old animals (2 yr of age); and (3) cyclic nucleotides-dependent intracellular mechanisms are involved in control of rabbit reproductive functions and IBMX, an activator of these mechanisms, can be a stimulator of reproduction and fertility.     

Early conception factor lateral flow assays for pregnancy in the mare

The ECF™ lateral flow assay test is marketed to detect non-pregnancy in mares. The objectives of the present study were to determine the accuracy of the ECF test, the accuracy of the electronic reader accompanying the ECF test, and agreement between two human readers and the electronic reader. Serum samples were collected from anestrus, cycling but not inseminated, and inseminated mares, and were evaluated with the ECF™ test (EDP Biotech Company, Knoxville, TN, USA) at The Ohio State University and at the EDP Biotech Laboratory. Specificity ranged from 0.07 to 0.16, the negative predictive value ranged from 0.15 to 0.33, and accuracy ranged from 0.43 to 0.52. The electronic reader did not add improve the accuracy or predictive values of the test. Based on the electronic reader, 80.0% of the serum samples collected from the anestrus mares were false positives; Readers 1 and 2 had 60.0 and 33.3% false positives, respectively. For samples collected during the estrous cycle, 83.9% were false positives by the electronic reader, whereas Readers 1 and 2 had 43.7 and 26.4% false positives. We concluded that, regardless of whether the test strips were evaluated by a human or electronic reader, this assay was not accurate for determination of the non-pregnant mare.     

Determination of ovulation and pregnancy in the marmoset (Callithrix jacchus) by monitoring of urinary hydroxypregnanolone excretion

In Callithrix jacchus the urinary excretion of hydroxypregnanolone (5 alpha-pregnane-3 alpha, 7 alpha-diol-20-one) shows a luteal rise during the ovulatory cycle. This progesterone metabolite can therefore be used as an indication of ovulation, implantation, and subsequently for the persistence of the pregnancy. The excretion can be monitored by high performance thin-layer chromatography (HPTLC) and postchromatographic derivatization after enzymatic hydrolysis of the conjugate. Profiles of urinary hydroxypregnanolone levels are presented and correlated with luteinizing hormone excretion. The method is noninvasive and therefore suited for long-term studies in these monkeys.     

孕期规律运动与妊娠期糖代谢异常关系的研究

目的探讨不同方式干预孕期运动与妊娠期糖代谢异常的关系及对妊娠结局的影响。方法将300例孕14周单胎孕妇按阶段分为两组各150例,干预组对孕妇进行评估,建立孕妇档案,孕期通过个体化运动干预,给予孕妇个体化、具体的适度运动处方及给予督导规律运动;对照组采用传统的产前检查及常规护理。观察比较两组孕妇血糖变化、体重增长及妊娠结局。结果干预组空腹,餐后2h血糖值,妊娠末期体重,发生糖代谢异常,早产儿、新生儿窒息、巨大儿以及剖宫产率均低于对照组,差异有统计学意义(P0.05)。结论通过个体化护理对孕期运动进行干预,有效控制血糖值,降低母婴并发症的发生。     

Contributions of animal nutrition research in rostock to energetic feed evaluation

The Rostock research in animal nutrition has underlain in continuation and progressive development of Kellner's starch value system, net energy fat as measuring unit for energetic feed evaluation. Net energy‐fat was used as an uniform unit of measure for all farm animals with different performances. The scientific basis for the net energy‐fat system was created by numerous studies on energy retention and utilisation efficiency of pure nutrients and nutrients of feedstuffs and rations. For the estimation the energy content of feedstuffs and rations, multiple regression equations were derived on the basis of experimental results of the energy research group. The regressions for the estimation of energy values are used directly and modified in feed evaluation systems for practical use. The Rostock research group in energy metabolism created also essential contributions to factorial derivations of energy requirement of farm animals. In the presented paper selected results on maintenance energy requirement in relation to partial energy requirement values and utilisation efficiencies in growing, pregnant and lactating animals, especially cattle and pigs, are comprised. The Rostock results are compared to those from literature.     

Effect of nickel on red blood cell parameters and on serum vitamin B12, folate and homocysteine concentrations during pregnancy with and without anemia

BackgroundResearch to date suggests that nickel affects not only the metabolism of vitamin B12 but also folates and thus may affect hematopoiesis processes.ObjectiveThe aim of the study was to examine the relationship of nickel (Ni) status to red blood cell (RBC) parameters and serum vitamin B12, folate and homocysteine concentrations in the course of normal pregnancy and in pregnant women with anemia.MethodsThe study included fifty-three pregnant women recruited to the study from the Lower Silesia region of Poland, 17 % of whom developed anemia. Nickel concentration was determined in urine, whole blood and food samples by atomic absorption spectrometry. At the same time as the food and urine samples were taken, blood was also collected for the determination of RBC parameters and serum vitamin B12, homocysteine and folate concentrations.ResultsThe median reported Ni intake, and the urinary and whole blood nickel contents for the studied pregnant women for the first trimester were respectively – 162.46 μg/day, 3.98 μg/L and 3.32 μg/L; for the second trimester – 110.48 μg/day, 6.86 μg/L and 1.04 μg/L; and for the third trimester – 132.20 μg/day, 3.41 μg/L and 0.70 μg/L. With regard to Ni concentration in whole blood (p = 0.0204) and in urine (p = 0.0003), the differences in the values for individual trimesters were statistically significant. The whole blood Ni level was significantly higher (9.28 vs 3.62 μg/L, p = 0.0114), while the concentration of homosysteine was significantly lower (4.09 vs 5.04 μmol/L, p = 0.0165) in pregnant women with anemia compared to those without anemia. The whole blood Ni concentration was negatively correlated with almost all RBC parameters in non-anemic pregnant women.ConclusionsNi status changes with the development of normal pregnancy, and in the case of anemia, an increase in Ni concentration in whole blood is observed. The demonstrated correlations between the Ni status in pregnant women and RBC parameters as well as serum vitamin B12 and folate concentrations suggest that nickel is associated with the methionine–folate cycle, iron homeostasis and bacterial synthesis of vitamin B12 in humans.     

Higher serum homocysteine and lower thyroid hormone levels in pregnant women are associated with neural tube defects

BackgroundThis study tested the hypothesis that abnormal maternal metabolism of both homocysteine and thyroid hormone network in pregnant women is associated with neural tube defects (NTDs) in a part of China with high NTD prevalence.MethodsA case–control study was performed between 2007 and 2009 in Lüliang Mountains, Shanxi Province. This study included 83 pregnant women who had fetuses with NTDs (cases) and 90 pregnant women with normal fetuses (controls). In addition, a cell model to illustrate the epidemiological findings was established.ResultsFetuses of mother who had both high total homocysteine (tHcy) and inadequate free thyroxine were 3 times more at risk of developing NTDs (adjusted odds ratio = 3.5; 95 % confidence interval = 1.2–10.4; cases vs. controls) using multivariate logistic regression models. Furthermore, biological interaction between metabolisms of Hcy and thyroid hormones was demonstrated in vitro. In homocysteine thiolactone of a metabolite of Hcy-treated mouse embryonic neural stem NE4C cells, genes (Bmp7, Ctnnb1, Notch 1, Gli2, and Rxra) related to both neural tube closure and thyroid hormone network were shown to be regulated by H3K79 homocysteinylation, which increased their expression levels.ConclusionsThe effect of maternal serum high tHcy on risk of developing NTDs is depended on maternal serum level of thyroxine. Meanwhile, a higher level of tHcy might also affect both maternal metabolism of thyroid hormone and neural tube closure in embryogenesis through homocysteinylation of histones.