bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Composition of Lipids Present in Cat and Dog Oocyte by Matrix‐Assisted Desorption Ionization Mass Spectrometry (MALDI‐ MS)
Authors: Apparicio M , Ferreira CR , Tata A , Santos VG , Alves AE , Mostachio GQ , Pires‐Butler EA , Motheo TF , Padilha LC , Pilau EJ , Gozzo FC , Eberlin MN , Lo Turco EG , Luvoni GC , Vicente WRR 
Published: December 2012

ContentsThe aim of the present study was to investigate the level of information on the chemical structures and relative abundances of lipids present in cat and dog oocytes by matrix‐assisted laser desorption mass spectrometry (MALDI‐MS). The MALDI‐MS approach requires a simple analysis workflow (no lipid extraction) and few samples (two or three oocytes per analysis in this work) providing concomitant profiles of both intact phospholipids such as sphingomyelins (SM) and phosphatidylcholines (PC) as well as triacylglycerols (TAG). The lipids were detected in oocytes by MALDI using dihydroxybenzoic acid (DHB) as the matrix. The most abundant lipid present in the MS profiles of bitch and queen oocytes was a PC containing 34 carbons and one unsaturation [PC (34:1)]. Oocytes of these two species are characterized by differences in PC and TAG profiles detected qualitatively as well as by means of principal component analysis (PCA). Cat oocytes were mainly discriminated by more intense C52 and C54 TAG species and a higher number of unsaturations, indicating predominantly linoleic and oleic fatty acyl residues. Comparison of the lipid profile of bitch and queen oocytes with that of bovine oocytes revealed some similarities and also some species specificity: TAG species present in bovine oocytes were also present in bitches and queens; however, a more pronounced contribution of palmitic, stearic and oleic fatty acid residues was noticed in the lipid profile of bovine oocytes. MALDI‐MS provides novel information on chemical lipid composition in canine and feline oocytes, offering a suitable tool to concomitantly monitor, in a nearly direct and simple fashion the composition of phospholipids and TAG. This detailed information is highly needed to the development of improved protocols for in vitro culture and cryopreservation of cat and dog oocytes.
AZA Wildlife Contraception Center Programme for Wild Felids and Canids
Authors: Asa C , Boutelle S , Bauman K 
Published: December 2012

ContentsNorth American zoos began using melengestrol acetate (MGA) implants to control reproduction in wild felids in the mid‐1970s. Research linking MGA and other progestin‐based contraceptives to uterine and mammary pathology in canids as well as felids resulted in a shift to GnRH agonist implants (Suprelorin®: deslorelin, Peptech Animal Health, Australia). However, a recent study revealed an association between Suprelorin® and uterine pathology in canids, but that pathology was not found in canids treated with oral megestrol acetate (MA) for 2 weeks around the time of implant insertion to prevent the initial agonist stimulation phase. Thus, the AZA Wildlife Contraception Center (WCC) currently recommends Suprelorin® plus the 2‐week MA regimen for wild canids and felids. WCC research is now focusing on factors affecting Suprelorin® reversibility.
Leptin and Leptin Receptor Gene Expression in the Canine Corpus Luteum During Diestrus, Pregnancy and after Aglepristone‐Induced Luteolysis
Authors: Balogh O , Kowalewski MP , Reichler IM 
Published: December 2012

ContentsLeptin (LEP) and leptin receptor (LEP‐R) expression was shown to change throughout the luteal phase in several species and may be involved in steroid hormone production. In the bitch, leptin but not LEP‐R protein was detected in the non‐pregnant corpus luteum (CL). Until now, no further information has been available on their expression levels and role in CL function. Our objective was to compare time‐related changes in luteal LEP and LEP‐R mRNA levels during the non‐pregnant luteal phase, pregnancy and after aglepristone treatment in mid‐gestation. CLs were collected by ovariohysterectomy at different time points: day (d) 5, 15, 25, 35, 45, 65 after ovulation (p.o.) in non‐pregnant bitches; pre‐implantation, post‐implantation, mid‐gestation, during prepartum luteolysis; 24 and 72 h after aglepristone injection. Non‐pregnant LEP expression was lowest on d5 p.o., increased thereafter and fell again on d45 (P ≤ 0.04). LEP‐R expression was not altered (P = 0.07). In pregnant bitches, neither LEP nor LEP‐R mRNA levels varied over time (P = 0.201 and P = 0.150, respectively). Aglepristone treatment caused substantial downregulation of luteal LEP expression by 72h post‐treatment (P ≤ 0.01). However, LEP‐R expression did not follow the same course (P = 0.193). Our results indicate that both LEP and LEP‐R mRNA are present in the canine CL during the non‐pregnant luteal phase and pregnancy. LEP expression changes significantly over time in non‐pregnant dogs and after aglepristone administration and thus, it may play a role in luteal steroidogenesis and regression.
Prediction of Parturition in Dogs and Cats: Accuracy at Different Gestational Ages
Authors: Beccaglia M , Luvoni GC 
Published: December 2012

ContentsIn bitches and queens, the ultrasonographic measurement of extrafoetal and foetal structures allows the evaluation of gestational age and the prediction of the parturition term for an extended period of time. The aim of this study was to investigate whether the accuracy of parturition date prediction is affected by the week of pregnancy when the ultrasonographic examination is performed. The results were obtained by retrospective analysis on the gestational period basis (from week 4 to week 9 of pregnancy) in 495 ultrasonographic examinations of pregnant bitches (small and medium size) and 60 of pregnant queens. They demonstrated that a similar accuracy (p > 0.05) was obtained by the measurement of inner chorionic cavity at week 4 and 5 of pregnancy (±1 day, 81% vs 67.7%; ±2 days, 93.1% vs 85.9%). Accuracy (±1 day) based on biparietal (BP) measurement was similar at week 5 and 6 of pregnancy (78.6% vs 78.9%; p > 0.05), whereas a significant decrease (p < 0.05) was observed at week 7 and 8 compared to week 6. No difference in the accuracy of the prediction at ±2 days based on BP was observed from week 5 to 8 of gestation (range from 82.3% to 95.2%). Close to term (week 9), the accuracies of the prediction based on BP were significantly lower than those obtained at week 5 (±1 day: 50.9% vs 78.6%, p < 0.05; ±2 days: 69.8% vs 95.2%, p < 0.005). The accuracy of the prediction in bitches and queens is influenced by the gestational period when ultrasonographic measurements are performed, particularly for BP measurement. Although a decrease in BP accuracy occurs along the pregnancy, the accuracy at ±1 and ±2 days of prediction of parturition term is highly consistent for 6 and 8 weeks of gestation, respectively.
Are Oocytes from the Anestrous Bitch Competent for Meiosis?
Authors: Chastant‐Maillard S , Saint‐Dizier M , Grimard B , Chebrout M , Thoumire S , Reynaud K 
Published: December 2012

ContentsIn the bitch, oocyte meiosis resumption takes place in the oviduct. Using oocytes from anestrous bitches, in vitro maturation (IVM) generally gives very poor results. To investigate the contribution of oocyte competence to the low IVM yield, we compared in vivo maturation in an optimal environment with conventional IVM. A total of 418 grade 1 cumulus‐oocyte complexes (COCs) from 10 anestrous bitches were transferred into the oviducts of recipient bitches either on Day −1 (n = 3 recipients), Day 0 (n = 2) or on Day +1 (n = 2) relative to ovulation. For each donor bitch, 20 grade 1 COCs were also cultured in vitro. After 72 h of in vivo or IVM, the nuclear stage of oocytes was determined after DNA and tubulin staining. Of the 154 oocytes recovered and examined after intratubal transfer, only 2% reached the metaphase I or II stage and 38.3% were degenerated. Oocytes cultured in vitro displayed a higher metaphase rate (7.6%, n = 170) and lower degeneration rate (12.9%) compared with transferred oocytes (p < 0.001). These results clearly demonstrate that the oocyte competence is the major limiting factor of IVM efficiency in the dog. Mimicking the tubal environment may thus not be sufficient to increase IVM yield in this species.
Timing of the Intestinal Barrier Closure in Puppies
Authors: Chastant‐Maillard S , Freyburger L , Marcheteau E , Thoumire S , Ravier JF , Reynaud K 
Published: December 2012

ContentsAs puppies are born with very low immunoglobulin concentrations, they rely on passive immune transfer from ingested colostrum to acquire a protective immunity during the first few weeks of life. The purpose of this study was to describe the timing of gut closure in canine neonates. Twenty‐twoBeagle puppies received 3 ml of standardized canine colostrum at 0, 4, 8, 12, 16 or 24 h after birth using a feeding tube. Blood immunoglobulinsG(IgG,MandA) were assayed 0, 4 and 48 h after colostrum ingestion.IgGabsorption rate was significantly affected by the time of colostrum administration, and theIgGconcentrations in puppies serum 48 h after administration were significantly higher when colostrum was ingested at 0–4 h of age than at 8–12 h or 16–24 h (1.68 ± 0.4, 0.79 ± 0.07 and 0.35 ± 0.08 g/l, respectively; p < 0.001). In the canine species, gut closure seems thus to begin as early as 4–8 h after birth and to be complete at 16–24 h. Consequently, this phenomenon appears to occur earlier in puppies than in most other species.
Effects of Cold Storage Prior to Freezing on Superoxide Dismutase, Glutathione Peroxidase Activities, Level of Total Reactive Oxygen Species and Sperm Quality in Dogs
Authors: Chatdarong K , Chaivechakarn A , Thuwanut P , Ponglowhapan S 
Published: December 2012

ContentsReactive oxygen species (ROS) are one of several crucial factors that cause mammalian sperm damage during handling and preservation. Their deleterious effects can be restricted by the action of antioxidants. The present study aimed at investigating: (i) effects of cold storage prior to freezing on activities of enzymatic antioxidants (superoxide dismutase; SOD and glutathione peroxidase; GPx) and level of total reactive oxygen species (tROS); and (ii) effects of SOD or SOD plus GPx supplementation to chilled (3 and 96 h) and frozen‐thawed semen. Six privately owned dogs were included. Experiment I: Each pooled semen was divided into three equal aliquots, which were subjected to chilled storage for 3, 24 or 96 h prior to freezing (n = 7). The activities of SOD and GPx in sperm cells and tROS level in chilled and frozen‐thawed semen were measured. Experiment II: Pooled semen was divided to be cold stored for 3 or 96 h in three different extenders; (i) Uppsala Equex extender (control), (ii) Uppsala Equex extender supplemented SOD, or (iii) Uppsala Equex extender supplemented with SOD plus GPx. Sperm motility, viability and integrity of acrosome and DNA was evaluated after cold storage and frozen‐thawed. The cold storage from 24 h prior to freezing resulted in a decrease in the SOD activity in the frozen‐thawed sperm cells whereas the GPx activity and tROS levels were not affected. In addition, the supplementation of SOD plus GPx enhanced the percentage of sperm viability and DNA integrity after cold stored and frozen‐thawed. In sum, the SOD activity is compromised by cold storage prior to freezing of dog semen. Addition of GPx is suggested to assist SOD to complete the enzymatic ROS scavenging system in the dog sperm.
On the Horizon for Fertility Preservation in Domestic and Wild Carnivores
Authors: Comizzoli P , Wildt DE 
Published: December 2012

ContentsInnovations are emerging from the growing field of fertility preservation for humans and laboratory animals that are relevant to protecting and propagating valuable domestic and wild carnivores. These extend beyond the ‘classical’ approaches associated with sperm, oocyte and embryo freezing to include gonadal tissue preservation combined with in vitro culture or xenografting, all of which have potential for rescuing vast amounts of unused and wasted germplasm. Here, we review approaches under development and predicted to have applied value within the next decade, including the following: (i) direct use of early‐stage gametes for in vitro fertilization; (ii) generation of more mature gametes from gonadal tissue or stem cells; (iii) simplification, enhanced safety and efficacy of cryopreservation methods; and (iv) biostabilization of living cells and tissues at ambient temperatures. We believe that all of these fertility preservation strategies will offer knowledge and tools to better manage carnivores that serve as human companions, valuable biomedical models or require assistance to reverse endangerment.
Ex vivo Recovery of Preimplantatory Embryos in Bitches
Authors: Commin L , Buff S , Rosset E , Joly T , Guerin P , Neto V 
Published: December 2012

ContentsThe present study was conducted to investigate the timing of preimplantatory development in the dog and to evaluate the efficiency of flushing oviducts and uterine horns to collect embryos. Among the embryonic structures collected between day 8 and day 12 after ovulation, 43 % were at the 1–16 cells stage, 23% were at the morula stage and 34% at the blastocyst stage. Our collection method yielded to a recovery rate of 61.3 %, and 7.1 ± 0.7 embryos were harvested per bitch. In addition, the ovulation rate reached 11.6 ± 0.8 per bitch. The first morulae were observed from day 9 post‐ovulation, while the first blastocyst appeared from day 10. Two‐thirds of the collected morulae‐blastocysts were obtained between the 11th and the 12th day after ovulation. To the moment, we suggest this is the best period to harvest canine embryo for cryopreservation.
Factors Influencing Annual Fecal Testosterone Metabolite Profiles in Captive Male Polar Bears (Ursus maritimus)
Authors: Curry E , Roth TL , MacKinnon KM , Stoops MA 
Published: December 2012

ContentsThe objectives of this study were to assess the effects of season, breeding activity, age and latitude on fecal testosterone metabolite concentrations in captive, adult male polar bears (Ursus maritimus). Fourteen polar bears from 13 North American zoos were monitored for 12–36 months, producing 25‐year‐long testosterone profiles. Results indicated that testosterone was significantly higher during the breeding season (early January through the end of May) compared with the non‐breeding season with the highest concentrations excreted from early January through late March. Variations in excretion patterns were observed among individuals and also between years within an individual, with testosterone peaks closely associated with breeding activity. Results indicate that fecal testosterone concentrations are influenced by season, breeding activity and age, but not by latitude. This is the first report describing longitudinal fecal testosterone metabolite concentrations in individual adult male polar bears.
Sperm Nuclear Decondensation Induction Capacity of In Vitro and In Vivo Matured Canine Oocytes
Authors: De los Reyes M , Palomino J , Parraguez VH , Vergara J 
Published: December 2012

ContentsThe objectives of this study were to evaluate the sperm nuclear decondensation capacity of ovulated and in vitro‐matured (IVM) canine oocytes during different culture times and correlate this decondensation ability with the state of oocyte nuclear maturation in vitro and in vivo. Fresh ejaculates from three dogs were used for in vitro fertilization (IVF). Dog spermatozoa were cocultured with ovulated or IVM oocytes after each culture period (0, 48, 72 and 96 h) for 24 h. The nuclear stage of the oocytes and the appearance of the sperm nucleus were determined, and data were analysed with a chi‐square test. The rates of decondensation and meiotic development in IVM oocytes increased up to 72 h of culture. In contrast, almost all in vivo‐matured oocytes showed MII nuclear stage and sperm chromatin decondensation. The percentages of oocytes at MII stage were much lower (p < 0.05) in all IVM groups compared with ovulated oocytes; the rate of sperm chromatin decondensation was higher in ovulated oocytes than in those matured in vitro. Thus, IVM canine oocytes are able to decondense the sperm chromatin during IVF, and this ability increases with time. Nevertheless, sperm chromatin decondensation is less efficient than in ovulated oocytes and may not be completely synchronized with nuclear development as it occurs in vivo.
Golgi Apparatus and Endoplasmic Reticulum Dynamic during Meiotic Development in Canine Oocytes
Authors: De los Reyes M , Palomino J , Jofré S , Villarroel A , Moreno R 
Published: December 2012

ContentThe Golgi apparatus (GA) and endoplasmic reticulum (ER) play a central role in the events related to intracellular trafficking distribution. This work evaluated the dynamics and localization of the GA and ER in canine oocytes during meiotic development in vitro. Cumulus–oocytes complexes (COCs) from ovaries of adult bitches were incubated for IVM for 0, 48, 72 and 96 h. At each time, the nuclear status was determined using DAPI staining, and the GA was evaluated by immunofluorescence using two antibodies against Golgi proteins: GM130 and Giantin. ER was analysed with fluorescent lipid probes (ER‐Tracker), for living cells. Golgi structures were homogeneous in the cytoplasm in non‐matured oocytes, mainly in those GV‐arrested oocytes. In contrast, at 48 h and from GVBD stage, the immunolocalization began to be subcortical, increasing at 72 h and 96 h. Meiotic development increased with time and the majority of oocytes at MI‐MII stages showed cortical distribution of Golgi structure. Living ZP intact non‐matured oocytes showed a reticular pattern of ER that covered oocyte cortex. Confocal microscopy showed that, in all levels cuts the fluorescence marks were located in the cortical region, irrespective of culture time. The changes and localization in these organelles during IVM might be related to meiotic development, but in a non‐synchronous manner.
Progesterone (PR), Oestrogen (ER‐α and ER‐β) and Oxytocin (OTR) Gene Expression in the Oviduct and Uterus of Pregnant and Non‐pregnant Bitches
Authors: Derussi AAP , de Souza RWA , Volpato R , Guaitolini CRF , Ackermann CL , Taffarel MO , Cardoso GS , Dal‐Pai‐Silva M , Lopes MD 
Published: December 2012

ContentsThe aim was to assess hormone receptor gene expression in the oviduct and uterus during canine pregnancy. Nineteen pregnant bitches divided into four groups were ovariohysterectomized (OVH) at either day 8, 12, 21 or 60 of pregnancy, and five non‐pregnant females underwent OVH 12 days after the pre‐ovulatory Luteinizant Hormone (LH) surge and served as controls. RT‐qPCR for progesterone (PR), oestrogen (ER‐α and ER‐β) and oxytocin (OTR) receptors was performed on the oviduct and uterine tissue. The mRNA PR expression in the uterus during early stages of pregnancy and the luteal phase was higher than at other times. The mRNA ER‐β expression in the oviduct during early pregnancy was less than in non‐pregnant bitches. In the uterus, the mRNA ER‐β expression was higher in the initial stages of pregnancy. The ER‐α expression was higher in the oviduct and uterus in advanced stages of pregnancy. The mRNA OTR expression in the oviduct was lower than in the uterus in control group. The expression of this receptor in oviduct and the uterus was higher in the final stages of pregnancy, when compared with other phases. These data suggested that the serum progesterone concentrations probably exert a direct control on the PR and ER (α and β) expression and indirectly on OTR expression in the bitch oviduct and uterus.
Applying Gene Silencing Technology to Contraception
Authors: Dissen GA , Lomniczi A , Boudreau RL , Chen YH , Davidson BL , Ojeda SR 
Published: December 2012

ContentsPopulation control of feral animals is often difficult, as it can be dangerous for the animals, labour intensive and expensive. Therefore, a useful tool for control of animal populations would be a non‐surgical method to induce sterility. Our laboratories utilize methods aimed at targeting brain cells in vivo with vehicles that deliver a payload of either inhibitory RNAs or genes intended to correct cellular dysfunction. A useful framework for design of a new approach will be the combination of these methods with the intended goal to produce a technique that can be used to non‐invasively sterilize cats and dogs. For this approach to succeed, it has to meet several conditions: the target gene must be essential for fertility; the method must include a mechanism to effectively and specifically silence the gene of interest; the method of delivering the silencing agent must be minimally invasive, and finally, the silencing effect must be sustained for the lifespan of the target species, so that expansion of the population can be effectively prevented. In this article, we discuss our work to develop gene silencing technology to induce sterility; we will use examples of our previous studies demonstrating that this approach is viable. These studies include (i) the use of viral vectors able to disrupt reproductive cyclicity when delivered to the regions of the brain involved in the control of reproduction and (ii) experiments with viral vectors that are able to ameliorate neuronal disease when delivered systemically using a novel approach of gene therapy.
Physiologic Responses Following Gonadotropin‐Releasing Hormone Immunization in Intact Male Dogs
Authors: Donovan CE , Greer M , Kutzler MA 
Published: December 2012

ContentsWe investigated the use of a commercial gonadotropin‐releasing hormone (GnRH) vaccine as a method of temporary and reversible immunocastration in intact male dogs. Four privately owned dogs were vaccinated twice at 4‐week intervals. Blood samples were collected at 0, 4, 12 and 20 weeks following the initial vaccination. These samples were analysed forGnRHantibody titres, luteinizing hormone (LH) and testosterone concentrations. Scrotal measurements were made at the time of sample collection, and testicular volume was calculated using the formula of an ellipsoid. As a result of vaccination, dogs displayed an elevatedGnRHantibody titre, decreasedLHand testosterone concentrations and decreased testicular volume, which reversed by the end of the study period. Therefore, these results suggest that immunizing againstGnRHmay be a possible choice for temporary and reversible immunocastration.
Effects of Cooling Time on Membrane Integrity and Motility of Frozen‐Thawed Canine Spermatozoa using Two Different Commercial Egg Yolk–based Extenders at Two Different Cooldown Equilibration Times
Authors: du Bois S , Len JA , Parlevliet JM , Eilts BE 
Published: December 2012

ContentsTwo commercially available egg yolk–based semen extenders, one marketed for human semen freezing (HEYE) and one marketed for canine semen freezing (CEYE), were used to cryopreserve semen from single ejaculates of 11 different dogs. For each extender, a 30‐ and a 60–min cooldown period was used prior to the addition of the extender containing glycerol and then immediately frozen in liquid nitrogen vapours. Sperm motility was measured using a computer‐assisted semen analysis (CASA) system. Sperm intact membranes were measured using SYBER‐14 and propidium iodide. Semen in the HEYE cooled for 60 min had a significantly greater percentage of intact membranes than the semen in the HEYE cooled for 30 min (p = 0.02). Semen in the HEYE cooled for 60 min had significantly greater total motility (p = 0.007) and progressive motility (p = 0.004) than semen cooled for 60 min in the CEYE and semen cooled for 30 min in the HEYE (total motility p = 0.02 and progressive motility p = 0.02). Semen cooled for 60 min in the CEYE did not differ significantly in total (p = 0.6) or progressive motility (p = 0.4) than semen cooled for 30 min in the CEYE. There was no difference in total (p = 0.8) or progressive motility (p = 0.8) between the semen cooled for 30 min in the HEYE and the semen cooled for 30 min in the CEYE.