bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Canine Pregnancy – A Battle for Successful Growth and Angiogenesis
Authors: Schäfer‐Somi S 
Published: December 2012

ContentsCurrently, no early pregnancy marker has been identified in the bitch. However, significantly decreased concentrations of heat‐shock protein (HSP) 70 and increased activity of matrix metalloproteinases (MMP) 2,9 were detected in serum from bitches during the pre‐implantation period between days 5 and 13 after mating, that is, 2–3 days after ovulation as determined by the measurement of progesterone and vaginal cytology. Especially during the implantation period and thereafter (days 15–55), high serum concentrations of antibodies against desmin are present, which is believed to indicate or regulate decidualization. Pre‐implantation embryos express mRNA for enzymes and cytokines, known to promote and regulate trophoblast growth, and some intrauterine changings like the increased activity of MMP 2,9 in maternal endometrium are dependant on the presence of embryos. Some mechanisms that protect canine embryos from attack by the maternal immune system can also be identified. The embryos express CD4, a receptor known to interact with immune cells. They, furthermore, do not express MHC I and II, which might prevent them from being recognized as foreign antigen. Pre‐implantation embryos express FasL, which probably renders them able to destroy Fas‐bearing cytotoxic T cells. Furthermore, the uterus during pre‐implantation and implantation expresses cytokines that modulate the intrauterine milieu towards a predominance of Th2 cells. During pre‐implantation and implantation, an increased uterine expression of platelet activating factor (PAF) and PAFR, vascular endothelial growth factor (VEGF) and EGFR2 as well as epithelial growth factor (EGF) is characteristic. Towards placentation, the upregulation of leukaemia inhibiting factor (LIF) and at placentation the expression of insulin‐like growth factor(IGF)2 and granulocyte–macrophage colony‐stimulating factor (GM‐CSF) are striking. Progesterone receptor (PR) appears to be downregulated inside the uterus except at placentation sites, presumably where it is essential for maintenance of pregnancy. In addition, receptor‐bound P4 regulates the activity of MMP 2,9. Apoptosis seems to be a further regulatory mechanism. Expression of Fas and FasL mRNA in uterine tissue is maximum until implantation, both factors then decreased significantly. These changings might indicate increased endometrial apoptosis and defence against maternal cytotoxic T cells, probably promoting trophoblast invasion. In human decidual stromal cells, GnRH is involved in the regulation of apoptosis, which is proposed to be similar in pregnant bitches, as GnRH‐R is expressed at canine implantation sites. Our work investigating immunological changes in pregnant bitches has elucidated aspects of the complex physiology of implantation but raises important questions about the mechanisms involved.
Is Apoptosis a Regulatory Mechanism During Early Canine Pregnancy?
Authors: Schäfer‐Somi S , Sabitzer S , Klein D , Tomaszewski C , Kanca H , Beceriklisoy HB , Kucukaslan I , Agaoglu R , Kaya D , Ay S , Aslan S 
Published: December 2012

ContentsFas is a membrane‐bound protein which upon activation causes programmed cell death. Fas ligand (FasL) binds Fas on target cells. Both these factors are known to regulate apoptosis at implantation in different species and thus might be involved in the regulation of implantation in dogs. The aim of the study was to assess the expression of Fas and FasL in canine uterine tissue throughout pregnancy as well as in pre‐implantation embryos using RT‐PCR and RT‐qPCR. Uterine tissues was collected from of 21 healthy pregnant bitches (group I: days 10–12, n = 5; group II: days 18–25, n = 6; group III: days 28–45, n = 6) and from 4 non‐pregnant bitches (controls: days 10–12). Pregnancy stage was determined by days after mating, that is, 2–3 days after ovulation as determined by vaginal cytology and progesterone measurement. After ovariohysterectomy, uteri from group I bitches were flushed with PBS and the embryos washed and stored frozen at −80°. Tissues from the other groups were taken from the implantation and placentation sites, respectively, covered with Tissue Tek® and frozen at −80°. Extraction of RNA was performed with Trizol Reagent and RT‐qPCR using SYBR green probes. In pre‐implantation embryos, only FasL but not Fas could be detected. In all tissues from pregnant and non‐pregnant bitches, both parameters were detectable. Before implantation (group I) expression of FasL resembled that of non‐pregnant bitches in early dioestrus and decreased significantly during implantation and thereafter (p < 0.05). Expression of Fas did not change significantly until day 45. The relative expression of Fas exceeded that of FasL at each stage investigated, which is comparable to observations of other species; however, high standard deviations indicate high individual differences. These preliminary results point towards a regulatory function of the Fas/FasL system during early canine pregnancy.
Diseases of the Canine Uterus
Authors: Schlafer DH 
Published: December 2012

ContentsLesions most commonly found in the canine and feline uteri fall primarily into two categories: (i) abnormalities of endometrial growth and repair and (ii) uterine infections with associated endometritis. Neoplastic conditions of the tubular genitalia of the bitch, with the possible exception of leiomyomas (tumours that arise from smooth muscle cells), are uncommon. Congenital lesions involving the uterus are relatively rare. The primary object of this paper is to provide a summary of the most common uterine lesions found in the canine and feline uterus using a series of images that underscore the most prominent and important gross diagnostic features of each.
Feline Gonads Exhibit Tissue Specific Alternative Splicing of Oestrogen Receptor Alpha (ESR1)
Authors: Schoen J , Sharbati S , Ritter J , Jewgenow K 
Published: December 2012

ContentsMale felids frequently show teratospermia. At least in the domestic cat model, teratospermia is accompanied by impaired regulation of testicular apoptosis. We hypothesize that this phenomenon is caused by dysregulations in oestrogen signalling pathways. Both classical oestrogen receptors (ESR1 and 2) are expressed in species and/or tissue‐specific manners and display different variants, inter alia, caused by alternative splicing. In vitro studies showed that exon deleted transcripts are translated into proteins and that some of the variants modify the effects of the full‐length ERs. It has been proposed that some of the functional and morphological dysregulations, for example, during spermatogenesis, could directly derive from this phenomenon. In the present basic study, we investigated the expression pattern of ESR1 splicing variants in the gonads of domestic cats. Testicular, epididymal as well as ovarian tissue samples were collected from routine castrations. ESR1 variants were detected by means of RT‐PCR using primers spanning one to three exons. We detected the variants Δ4 and Δ7 in all tissue samples investigated. Additionally, the testicular parenchyma expressed the variant Δ6 and double exon deletions of ESR1 (Δ4/6 and Δ6/7). Using an antiserum recognizing all previously identified ESR1 splicing variants, we revealed ESR1 proteins being expressed in nearly all cells of the testicular and ovarian parenchyma. ESR1 Δ6 protein, however, detected by an antiserum specifically raised against the Δ6 variant, was predominantly located in Sertoli cells. As the exon deletion variants are significantly expressed and show a distinct expression pattern, they could specifically modulate the cellular responsiveness to hormonal stimuli within the gonads.
Delay of Puberty and Reproductive Performance in Male Dogs Following the Implantation of 4.7 and 9.4 mg GnRH‐Agonist Deslorelin at an Early Pre‐pubertal Age
Authors: Sirivaidyapong S , Mehl NS , Trigg TE 
Published: December 2012

ContentsStray dogs are a significant problem in large cities. Contraception is an important and useful solution to control the growing population of these dogs. Early‐age neutering is an effective technique for canine population control; however, surgical neutering may not be possible in various situations. GnRH‐agonist implantation has been successful for long‐term reversible contraception in dogs. The efficacy of GnRH‐agonist implantation on long‐term suppression of reproductive performance was observed in male dogs. Eleven 4‐month‐old dogs were implanted with 4.7, 9.4 mg deslorelin or placebo. Sexual behaviour and testicular size were monitored every 2 months. Ejaculates were collected and evaluated at 8, 12, 15, 18, 24, 30, 32, 34 and 36 months of age. Dogs implanted with placebo were found to be healthy and in normal reproductive status. Most dogs (3/4) implanted with 4.7 mg deslorelin showed male sexual behaviour at age of 34 months old. From this group, two dogs had normal semen quality, while semen could not be collected from the other dog, and after castration, no sperm were obtained following epididymal flushing. One dog implanted 4.7 mg deslorelin and four dogs implanted with 9.4 mg deslorelin remained in the non‐pubertal reproductive status at 30–34 months. The delay to puberty was longer in dogs implanted with higher dose of GnRH agonist. Implantation of pre‐pubertal dogs with high doses of GnRH agonist will delay the onset of puberty and may be an effective strategy to reduce the number of unwanted breedings.
The Domestic Dog and Cat as Models for Understanding the Regulation of Ovarian Follicle Development In Vitro
Authors: Songsasen N , Comizzoli P , Nagashima J , Fujihara M , Wildt DE 
Published: December 2012

ContentsThe culture of ovarian follicles is an important tool for understanding the mechanisms controlling follicle development and differentiation of the oocyte. The benefit of recovering meiotically and developmentally competent oocytes from early stage follicles (primordial, primary, pre‐antral and early antral) also would be significant, ranging from rescue of genomes from endangered species to preserving fertility in women facing cancer treatments. This research field is at an early stage of scientific discovery. To‐date, live offspring from cultured primordial follicles that produced fertilizable oocytes has occurred only in the mouse. Progress in other more complex species has been limited because larger animals have longer durations of natural folliculogenesis, thereby requiring more culture time to generate fully grown follicles and oocytes. We believe the dog and cat are excellent models for understanding more about folliculogenesis in vitro. This review highlights what is known about this topic for these two species as well as future priorities. We have discovered that it is more challenging to maintain viability of primordial follicles within ovarian tissues in vitro in the dog than the cat. Nonetheless, it is possible to grow both isolated cat and dog pre‐antral follicles in culture. Although the follicles of both species have the capacity to increase in size and produce steroids, only cat oocytes appear morphologically normal. The reason for this striking difference between these two species is an area of high research priority. While much more fundamental data are required, we envision advanced technology that will allow harvesting oocytes from the vast, unused follicle stores sequestered within carnivore ovaries. These gametes have utility for reproducing genetically valuable dogs and cats that are ‘companions’ or biomedical models for investigating human disorders as well as for salvaging the genomes of rare canid and felid species that die before contributing to genetic management programs.
Cryopreservation of Canine Embryos and Resulting Pregnancies
Authors: Suzuki H 
Published: December 2012

ContentsThe assisted reproductive techniques used in dogs have strictly limited utility when compared with other mammals. Although successful somatic cell cloning has been reported, artificial insemination by frozen semen has been only readily available method for improved breeding for companion and working dogs. Recently, successful cryopreservation of embryos and subsequent embryo transfer with a non‐surgical technique in dog was reported. Application of embryo cryopreservation and transfer technology could contribute to breeding management in companion dogs, working dogs including guide dogs and drug‐detecting dogs and quarantine dogs. Such technology would also facilitate the transportation and storage of genetic materials and aid in the elimination of vertically transmitting diseases in the dog.
Laparoscopic Oviductal Embryo Transfer and Artificial Insemination in Felids – Challenges, Strategies and Successes
Authors: Swanson WF 
Published: December 2012

ContentsEmbryo transfer (ET) and artificial insemination (AI) are potentially invaluable techniques for the propagation and management of genetically valuable domestic cat and endangered nondomestic cat populations. Many of the challenges that impair the effective application of ET and AI in felids may be overcome by using laparoscopic oviductal (LO) approaches. LO‐ET and LO‐AI are minimally‐invasive procedures, requiring only two small skin incisions for insertion of a laparoscope and grasping forceps into the abdominal cavity to permit visualization and catheterization of the oviduct for embryo or semen deposition. With concurrent improvements in embryo culture systems and ovarian synchronization protocols, LO‐ET has proven effective over the past decade for propagation of laboratory cats, cat models of hereditary disease and nondomestic cats. To date, viable offspring have been produced following LO‐ET of non‐frozen and frozen‐thawed IVF‐derived embryos in eight cat hereditary disease models and two nondomestic cat species, the ocelot and sand cat. LO‐AI with low sperm numbers (c. 2–8 million motile) has shown similar efficacy to LO‐ET, resulting in high pregnancy percentages (50–70%) following insemination of gonadotropin‐treated domestic cats. Multiple kittens also have been produced in two hereditary disease models following LO‐AI with frozen semen, and both ocelot and Pallas' cat kittens have been born after LO‐AI with freshly‐collected semen. The application of LO‐ET and LO‐AI to felids has resulted in substantial improvement in the efficiency of assisted reproduction for genetic management of these invaluable domestic cat and wild cat populations.
Immunolocalization of Progesterone Receptors in the Canine Oviduct around Ovulation
Authors: Tahir MZ , Reynaud K , Mawa G , Thoumire S , Chastant‐Maillard S , Saint‐Dizier M 
Published: December 2012

ContentsIn the bitch, oocyte maturation, sperm storage, fertilization and early embryo development take place within the oviducts under high and increasing circulating progesterone concentrations. To investigate the potential effects of progesterone on the canine oviduct, nuclear progesterone receptors (PR) were localized. Oviducts were collected by ovariectomy from adult Beagle bitches during anestrus, after the onset of proestrus but prior to the Luteinizing Hormone (LH) peak (Pre‐LH), after the LH peak but before ovulation (Pre‐ov) and on Days 1, 4 and 7 after ovulation (n = 3 bitches per stage). The cellular distribution of PR was studied by immunohistochemistry (IHC) in the ampulla, isthmus and tubal part of the utero‐tubal junction (UTJ). Plasma progesterone and 17β‐oestradiol were assayed on the day of surgery. PR were specifically expressed in the nuclei of epithelial, stromal and muscular cells in the ampulla, isthmus and UTJ. The IHC scores did not vary from one oviductal region to another. However, the epithelium displayed higher scores than the stroma at anestrus, Pre‐ov, Days 4 and 7, and also higher scores than muscle at Days 4 and 7 (p < 0.05). Immunohistochemistry scores in the stroma and muscle decreased at Days 4 and 7 compared with previous stages (p < 0.05). Furthermore, muscular IHC scores were positively correlated with circulating 17β‐oestradiol concentrations and negatively correlated with circulating progesterone concentrations (p < 0.05). In conclusion, PR were identified in the canine oviduct, with differences in expression between tissues and times around ovulation, suggesting that progesterone may regulate tubal functions and reproductive events in this species.
Seasonal Aspects of Reproductive Physiology in Captive Male Maned Wolves (Chrysocyon brachyurus, Illiger 1815)
Authors: Teodoro LO , Melo‐Junior AA , Spercoski KM , Morais RN , Souza FF 
Published: December 2012

ContentsThe aim of the study was to evaluate the seasonality of andrological characteristics and hormonal profile of captive maned wolves (Chrysocyon brachyurus, Illiger 1811). Three adult males were evaluated from the Companhia Brasileira de Metalurgia e Mineração Scientific Breeding Center in Araxá, MG, Brazil, over 13 months. Semen was collected 2–3 times weekly and analysed. Scrotal circumference, biometrics and testicular volume were measured. Stool samples were collected 2–3 times weekly to analyse corticosteroid and testosterone metabolite concentrations. A success rate of 100% was achieved in the collection attempts during the breeding season (BS) and 77.8% during the non‐breeding season (NBS). The interval to achieve penile erection was 1–5 min in the BS and 6–10 in the NBS (p < 0.001). Of the ejaculates collected, 80.0% contained sperm during BS, while 28.6% did during the NBS. The ejaculate had only one fraction, was odourless, predominantly translucent (72.4%), with a watery appearance, pH 6.7 and osmolarity of 352.8 mOsmol. Seasonal influences were seen in ejaculate volume (1.3 ml vs 0.4 ml), number of spermatozoa per ejaculate (73.9 × 106 vs 6.1 × 106) and percentage of live sperm (82.0% vs 66.1%) between the BS and NBS (p < 0.05), respectively. A high percentage of major sperm defects were observed in both seasons (50.1% in BS; 65.7% in NBS). Testicular volume was larger (p < 0.05; right testicles 13.1 cm3 in BS vs 4.0 cm3 in NBS, while left testicles 12.9 cm3 in BS vs 5.3 cm3 in NBS) and testicular consistency increased in the BS. No difference was seen in the basal faecal metabolite concentrations of testosterone; however, the corticosteroid concentrations were higher in the BS. Based on these results, it is possible to conclude that the collection of semen is feasible in captive maned wolves without compromising libido, seminal characteristics and reproductive behaviour and that sperm production is influenced by seasonality; however, it appears that there is no seasonal influence on basal testosterone concentrations.
Birth of Kittens After the Transfer of Frozen–Thawed Embryos Produced by Intracytoplasmic Sperm Injection with Spermatozoa Collected from Cryopreserved Testicular Tissue
Authors: Tharasanit T , Buarpung S , Manee‐In S , Thongkittidilok C , Tiptanavattana N , Comizzoli P , Techakumphu M 
Published: December 2012

ContentsThe aim of this study is to produce live kittens from oocytes fertilized by intracytoplasmic sperm injection (ICSI) with frozen/thawed testicular spermatozoa. Spermatozoa were collected from thawed testicular tissue and subsequently injected into in vitro matured cat oocytes. At 24 h post‐ICSI, presumptive zygotes/cleaved embryos were treated with 10 μm forskolin for 24 h to reduce intracellular lipid content of embryos (delipidation). At 48 h after oocyte injection, cleaved embryos (2‐ to 8‐cell stage) were frozen in 10% (v/v) ethylene glycol‐based medium by a slow controlled rate method and stored in liquid nitrogen. To evaluate in vitro and in vivo developmental competence, frozen embryos were thawed and then cultured for 6 days (n = 155) or cultured for 2 h before transferred (n = 209) to hormonal (equine chorionic gonadotropin/hCG)‐treated cat recipients. Cleavage frequency at day 2 after ICSI with frozen/thawed testicular spermatozoa was ~30%. The percentages of frozen/thawed embryos that developed to morula and blastocyst stage (on day 3 and day 6 of in vitro culture, respectively) were significantly lower than that of fresh ICSI embryos (22.6 vs 45.2% and 21.3 vs 38.7%, respectively; p < 0.05). However, no difference was found in the number of blastomeres between frozen/thawed (242.5 ± 43.1) and fresh (320.2 ± 28.1) blastocysts. Three of seven cat recipients were pregnant and one pregnant cat delivered two healthy kittens. This is the first report of the birth of kittens after the transfer of frozen–thawed embryos produced by ICSI with frozen/thawed testicular sperm.
Effect of Storage Media and Storage Time on Histological and Ultrastructural Changes in Cat Epididymal Cells
Authors: Tittarelli CM , Jurado SB , Nuñez‐Favre R , Bonaura MC , de la Sota RL , Stornelli MA 
Published: December 2012

ContentsThe aim of this study was to assess the histological and ultrastructural changes in cat epididymides (n = 22) stored at 4°C in two different media [saline solution (SAL) or tris‐egg yolk (TEY)]. Our hypothesis was that epididymides stored in TEY would have delayed epithelial cell autolysis. Four epididymides were fixed and processed immediately, and the remaining 18 epididymides were stored at 4°C in SAL or TEY for 24, 48 or 72 h. In histological sections, the nuclear features and stereocilia morphology were scored from 0 to 3. Ultrastructurally, nuclear chromatin and stereocilia morphology were scored from 0 to 3. In addition, using transmission electron microscopy nuclear number, nuclear area, mitochondrial number and mitochondrial area were recorded. In the histological study, parameters changed with time and media (p < 0.01). A significant effect of time was observed (p < 0.01), and the morphological changes were greatest when the storage time increased. Morphological changes were higher in SAL compared with TEY (p < 0.01). In the ultrastructural study, nuclear chromatin and stereocilia morphology decreased with time and media as in the histological study (p < 0.01). In addition, nuclear number and nuclear area changed with time (p < 0.004; p < 0.001) but not with media. Conversely, mitochondrial number and mitochondrial area did not change with media or time (p > 0.05). In conclusion, these results show that TEY preserved epididymal epithelial cells better than SAL; this finding could help improve sperm quality of stored epididymides.
Spermatogenic Function in Cats
Authors: Tsutsui T , Oba H , Fujimoto S , Toyonaga M 
Published: December 2012

ContentsThere are limited data on feline sperm production. We exhausted epididymal spermatozoa (i.e. the number of ejaculated spermatozoa <5 × 106) by frequent semen collections using the artificial vagina method in five tomcats and determined the number of spermatozoa stored in the epididymis. We investigated the time (days) required for the number of epididymal spermatozoa to return to the pre‐exhaustion level and determined the number of spermatozoa produced per day. After spermatozoa were exhausted by frequent semen collection, 6 or more days were required to return to the pre‐exhaustion level. Based on the duration of resting (days) and total number of spermatozoa, the mean number of spermatozoa produced per day was 30 × 106.