Insulin-like peptide genes in honey bee fat body respond differently to manipulation of social behavioral physiology

Nutrient sensitive insulin-like peptides (ILPs) have profound effects on invertebrate metabolism, nutrient storage, fertility and aging. Many insects transcribe ILPs in specialized neurosecretory cells at changing levels correlated with life history. However, the major site of insect metabolism and nutrient storage is not the brain, but rather the fat body, where functions of ILP expression are rarely studied and poorly understood. Fat body is analogous to mammalian liver and adipose tissue, with nutrient stores that often correlate with behavior. We used the honey bee (Apis mellifera), an insect with complex behavior, to test whether ILP genes in fat body respond to experimentally induced changes of behavioral physiology. Honey bee fat body influences endocrine state and behavior by secreting the yolk protein precursor vitellogenin (Vg), which suppresses lipophilic juvenile hormone and social foraging behavior. In a two-factorial experiment, we used RNA interference (RNAi)-mediated vg gene knockdown and amino acid nutrient enrichment of hemolymph (blood) to perturb this regulatory module. We document factor-specific changes in fat body ilp1 and ilp2 mRNA, the bee`s ILP-encoding genes, and confirm that our protocol affects social behavior. We show that ilp1 and ilp2 are regulated independently and differently and diverge in their specific expression-localization between fat body oenocyte and trophocyte cells. Insect ilp functions may be better understood by broadening research to account for expression in fat body and not only brain.

Brood cell size of Apis mellifera modifies the reproductive behavior of Varroa destructor

We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells.

Genetic associations between accumulated productivity, and reproductive and growth traits in Nelore cattle

The total meat yield in a beef cattle production cycle is economically very important and depends on the number of calves born per year or birth season, being directly related to reproductive potential. Accumulated Productivity (ACP) is an index that expresses a cow`s capacity to give birth regularly at a young age and to wean animals of greater body weight. Using data from cattle participating in the ""Program for Genetic Improvement of the Nelore Breed"" (PMGRN - Nelore Brasil), bi-trait analyses were performed using the Restricted Maximum Likelihood method based on an ACP animal model and the following traits: age at first calving (AFC), female body weight adjusted for 365 (BW365) and 450 (BW450) days of age, and male scrotal circumference adjusted for 365 (SC365), 450 (SC450), 550 (SC550) and 730 (SC730) days of age. Median estimated ACP heritability was 0.19 and the genetic correlations with AFC, BW365, BW450, SC365, SC450, SC550 and SC730 were 0.33, 0.70, 0.65, 0.08, 0.07, 0.12 and 0.16, respectively. ACP increased and AFC decreased over time, revealing that the selection criteria genetically improved these traits. Selection based on ACP appears to favor the heaviest females at 365 and 450 days of age who showed better reproductive performance as regards AFC. Scrotal circumference was not genetically associated with ACP. (C) 2007 Elsevier B.V. All rights reserved.

Diabetes and Vascular Disease: Basic Concepts of Nitric Oxide Physiology, Endothelial Dysfunction, Oxidative Stress and Therapeutic Possibilities

The vascular manifestations associated with diabetes mellitus (DM) result from the dysfunction of several vascular physiology components mainly involving the endothelium, vascular smooth muscle and platelets. It is also known that hyperglycemia-induced oxidative stress plays a role in the development of this dysfunction. This review considers the basic physiology of the endothelium, especially related to the synthesis and function of nitric oxide. We also discuss the pathophysiology of vascular disease associated with DM. This includes the role of hyperglycemia in the induction of oxidative stress and the role of advanced glycation end-products. We also consider therapeutic strategies.

Prenatal LPS exposure reduces olfactory perception in neonatal and adult rats

Prenatal lipopolysaccharide (LPS) exposure causes reproductive, behavioral and neurochemical defects in both dams and pups. The present study evaluated male rats prenatally treated with LPS for behavioral and neurological effects related to the olfactory system, which is the main sensorial path in rodents. Pregnant Wistar rats received 100 mu g/kg of LPS intraperitoneally (i.p.) on gestational day (GD) 9.5, and maternal behavior was evaluated. Pups were evaluated for (1) maternal odor preference, (2) aversion to cat odor, (3) monoamine levels and turnover in the olfactory bulb (OB) and (4) protein expression (via immunoblotting) within the OB dopaminergic system and glial cells. Results showed that prenatal LPS exposure impaired maternal preference and cat odor aversion and decreased dopamine (DA) levels in the OB. This dopaminergic impairment may have been due to defects in another brain area given that protein expression of the first enzyme in the DA biosynthetic pathway was unchanged in the OB. Moreover, there was no change in the protein expression of the DA receptors. The fact that the number of astrocytes and microglia was not increased suggests that prenatal LPS did not induce neuroinflammation in the OB. Furthermore, given that maternal care was not impaired, abnormalities in the offspring were not the result of reduced maternal care. (C) 2011 Elsevier Inc. All rights reserved.

Reproductive toxic effects of Tityus serrulatus scorpion venom in rats

Tityus serrulatus is the most venomous scorpion in Brazil. Little is known about the effect of maternal exposure to the venom on fetal development. We investigated the effect of low to moderate doses of the venom (0.3 or 1.0 mg/kg s.c. on either day 5 or day 10 of gestation) on pregnant rats and on their offspring. For dams, we observed their body weight gain and reproductive parameters. For the offspring, we observed their body weight and weight of internal organs and the number of live and dead fetuses, and we investigated whether the venom caused external, visceral, skeletal or histopathological alterations in the offspring. The offspring were examined on gestational day 21. Injection of the venom on gestational day 5 did not change the reproductive parameters of the dams, their weight or fetuses` weight. Rats that received the high dose of the venom (1.0 mg/kg) on gestational day 10 had heavier placentas and heavier fetuses with heavier lungs. Injections on day 10 of gestation did not alter the reproductive parameters of the dams nor their weight gain at either dose. The venom did not cause malformations of the fetal skeleton or viscera and did not delay fetal development with either dose. In conclusion, subcutaneous administration of 0.3 or 1.0 mg/kg T. serrulatus venom to pregnant Wistar rats at either day 5 or day 10 of gestation did not cause maternal or clear fetal toxicity. Subtle increases in placental weight and fetal body and lung weights observed following treatment with 1.0 mg/kg on day 10 of gestation were not associated with histopathological findings. Whether these observations represent a reaction to treatment and, if so, the underlying mechanisms and their toxicological impact remain to be examined further in future studies. (C) 2008 Elsevier Inc. All rights reserved.

Effects of equine chorionic gonadotropin and type of ovulatory stimulus in a timed-AI protocol on reproductive responses in dairy cows

The objectives were to evaluate the effects of equine chorionic gonadotropin (eCG) supplementation (with or without eCG) and type of ovulatory stimulus (GnRH or ECP) on ovarian follicular dynamics, luteal function, and pregnancies per AI (P/AI) in Holstein cows receiving timed artificial insemination (TAI). On Day 0, 742 cows in a total of 782 breedings, received 2 mg of estradiol benzoate (EB) and one intravaginal progesterone (P4) insert (CIDR). On Day 8, the CIDR was removed, and all cows were given PGF2 alpha and assigned to one of four treatments in a 2 x 2 factorial arrangement: (1) CG: GnRH 48 h later; (2) CE: ECP; (3) EG: eCG + GnRH 48 It later; (4) EE: eCG + ECP. There were significant interactions for eCG x ovulatory stimulus and eCG x BCS. Cows in the CG group were less likely (28.9% vs. 33.8%; P < 0.05) to become pregnant compared with those in the EG group (odds ratio [OR] = 0.28). There were no differences in P/AI between CE and EE cows (30.9% vs. 29.1%; OR = 0.85; P = 0.56), respectively. Thinner cows not receiving eCG had lower P/AI than thinner cows receiving eCG (15.2% vs. 38.0%; OR = 0.20; P < 0.01). Treatment with eCG tended to increase serum progestesterone concentrations during the diestrus following synchronized ovulation (P < 0.10). However, the treatment used to induce ovulation did not affect CL volume or serum progesterone concentrations. In conclusion, both ECP and GnRH yielded comparable P/AI. However, eCG treatment at CIDR removal increased pregnancy rate in cows induced to ovulate with GnRH and in cows with lower BCS. (C) 2009 Elsevier Inc. All rights reserved.

Correlation between serum and fecal concentrations of reproductive steroids throughout gestation in goats

Non-invasive techniques such as the measurement of fecal steroids are now widely used to monitor reproductive hormones in captive and free-ranging wild-life. These methods offer great advantages and deserve to be used in domestic animals. The aim of the present study was to determine the endocrine profile of dairy goats throughout pregnancy by the quantification of fecal progestins and estrogens and assess its con-elation with serum concentrations. Blood and fecal samples were collected weekly from I I adult, multiparous goats, from mating through pregnancy and 2 weeks post-partum. The extraction of estradiol and progesterone fecal metabolites was performed by dilution in ethanol. The radioimmunoassay (RIA) in solid phase was used to quantify serum 17 beta-estradiol (estradiol) and progesterone, as well as their fecal metabolites. The mean concentrations of both fecal and serum estradiol started to increase between weeks 7 and 11, reached peak values near parturition and then decreased sharply (range: 19.8 +/- 5.8 ng/g of feces to 608.6 +/- 472.4 ng/g of feces and 0.007 +/- 0.005 ng/ml to 0.066 +/- 0.024 ng/ml). An increase in both fecal and blood progestagens occurred in the second week, mean concentrations remained greater until week 20, and then decreased in the last week of gestation and 2 weeks post-partum (range: 108.8 +/- 43.6 ng/g of feces to 3119.5 +/- 2076.9 ng/g of feces and 0. 12 +/- 0.04 ng/ml to 13.10 +/- 4.29 ng/ml). The changes in blood and fecal hormone concentrations were analyzed and compared throughout gestation for each single goat, for each breed and for the whole group. Results indicated that matched values of serum and fecal hormone concentrations were correlated (r = 0.79; p < 0.001 for progesterone and r = 0.84;p < 0.001 for estradiol mean concentrations in the whole group). Regression analysis showed that logarithmic model allows significant prediction of serum from fecal concentrations with an R-2 = 0.729 (y = 0.013 1n x - 0.021) for estradiol and R-2 = 0.788 (y = 3.835 1n x - 18.543) for progesterone. Neither fecal nor serum concentrations were affected by the breed but a significant effect of the number of fetuses on progestin concentrations was found. Therefore, the profiles of progesterone and estradiol fecal metabolites reflect the serum concentrations of the same hormones in pregnant goats. (C) 2006 Elsevier B.V. All rights reserved.

Cell cycle and apoptosis in normal and cloned bovine near-term placentae

The bovine maternal epithelium is composed of cuboidal cells interspersed with low columnar cells having centrally located nuclei. Bovine trophoblast is composed of two cell types: mononuclear trophoblastic and giant trophoblastic cells that can have two or more nuclei. Number of apoptotic cells and proliferative cells are variable in both cell populations. This study compared tissue growth and apoptosis by flow cytometry in the cell population found at distinct placental regions (central region of placentomes, <= 1-cm microplacentomes and the interplacentomal region) between normal and cloned near-term bovine pregnancies. After a morphological comparison between regions and groups (controls vs. clones), a lesser proportion of diploid to tetraploid cells was observed in the central region of placentomes and in microplacentomes from cloned-derived pregnancies. In addition, cloned animals had a fewer apoptotic cells in the central region of the placentome and in interplacentomal region and a greater proliferative capacity in all regions (cells in G(2)/M) near term as opposed to control animals. These results may reveal the existence of a relationship between such changes in the proportions of uterine and trophoblastic epithelial cells at the end of pregnancy and normal placental function. This could be related to faulty placentation in early pregnancy, placental insufficiency during pregnancy or lack of placental and/or fetal maturation in late pregnancy, which may contribute to someof the abnormalities after in vitro embryo manipulations, such as poor preparation and initiation of parturition, prolonged gestation and lesser post-natal survival in some cloned animals. (C) 2008 Elsevier B.V. All rights reserved.

Acid-Base Changes in Canine Neonates Following Normal Birth or Dystocia

There are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid-base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.