9 research outputs found

    Understanding the Reproductive Biology of the Przewalski's Horse (Equus ferus przewalskii)

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    The Przewalski's horse (Equus ferus przewalskii) once roamed the Eurasian Steppe but is now considered Critically Endangered with only 1872 individuals remaining in the world, representing progeny from only 14 founder animals (Lee and Boyd, 2008). Genetic diversity needs to be optimal for long term survival of this species. Unfortunately, increasing genetic diversity of the captive population in North America has been hindered by a decrease in fertility. Therefore, the main focus of this research was to characterize reproductive parameters in Przewalski's horse, including estrus cycle in mares and seminal traits in stallions, and determining whether age or inbreeding had an impact on these traits. A secondary focus was to determine whether hormone manipulation of the estrous cycle in mares could be utilized for the long-term goal of using artificial insemination as a breeding management tool for this species. To facilitate these studies, a technique for palpation of Przewalski's mares was developed; the first application of such a procedure in a wild equid. Subsequently, we were able to describe follicular changes in relation to urinary hormone patterns. Fifty percent of the mares had either irregular or acyclic hormonal and follicular patterns. These patterns were directly correlated with inbreeding which is the first time such a correlation has been described in this species. Estrous manipulation was possible using an injectable biorelease form of the progestagen, altrenogest. In stallions, we developed a reliable method of semen collection for Przewalski's stallions and, as a result, describe seminal traits from 98 semen collections from 14 stallions. Based on these collections, we were able to show that sub-fertility in this population could be due to the low percentage of normal spermatozoa. Based on variable analysis, seminal traits total concentration, volume and morphology showed variable changes through the year. Traits also varied on an individual stallion basis. Together, these studies demonstrated that inbreeding is detrimentally affecting the reproductive fitness of this species and that aggressive management is needed for long term sustainability of the captive population

    Prostaglandins and utero-ovarian relationships in the sheep

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    Previous work on the control of luteal function in the oestrous cycle of the sheep is assessed and discussed. The experimental work produced the following conclusions:-1. No difference was found between PGF₂α and PGE₂ content and synthesizing ability of the uterine caruncular and non-caruncular endometrial tissue; but the uterine myometrial tissue contained significantly less and produced less PGF₂α than did the endometrial tissues.2. A significantly higher PGF₂α content was found in the second half of oestrous cycle than in the first half3. No significant changes was found either in the content or synthesizing ability of PGE₂ and 6-oxo-PGF₁αof the different uterine tissue indicating that these compounds are probably not involved in luteolysis.4. Plasma concentrations of PGF₂α were episodic in nature and showed an increase at about day 12 and 13 of the oestrous cycle. The largest release of PGF₂α occurred on the day after progesterone secretion by the CL had ceased. These findings appear to support the involvement of PGF₂α in luteolysis but also suggest that a major role for PGF₂α at the end of the cycle may be to complete luteolysis and to prevent any functional recovery of the CL.5. A significant relationship was found between the ability of endometrial tissue to synthesis PGF₂α and PGE₂ and between the endometrial content of PGF₂α and PGE₂. This suggests that either PGE₂ production is a by-product of PGF₂α production or that it is the availability of a common pre cursor that controls the synthesis of the two prostaglandins. However the availability of arachidonic acid was not a limiting factor.6. It was found that the endometrial synthesizing ability for PGF2a was significantly increased 3 and 2 days before the onset of oestrus in sheep with an ovary adjacent to the uterine tissue sampled but not in those animals with the adjacent ovary reÂŹ moved. This indicates that the presence of an ovary adjacent to the uterine horn is necessary for the normal manifistation of the PGF₂α synthesizing ability of the endometrium and suggests that the ovary exerts a local influence over endometrial PGF2a synthesizing ability in the adjacent uterine tissue.7. No relationships was found between plasma concentrations of PGF₂α and its endometrial content and synthesizing ability, thus implying that the release of PGF₂α is under independent control.8. A significant relationship was found between the concentrations of PGF₂α and progesterone in the uterine venous blood. This was most demonstrable when PGF₂α levels were compared with the progesterone level half-hour previously. This suggests that increased PGF₂α occurs in response to an increase in progesterone secretion and PGF₂α may thus play an important role in retaining the progesterone secretion at optimum during the luteal phase of oestrous cycle.9. Contrary to expectations, the anastomosis of the utero-ovarian vein to the anterior mammary vein but leaving the ovary in situ was found not to interrupt the normal oestrous cycle. This suggests the involvement of another route in the transfer of PGF2a to the adjacent ovary in addition to therormal route through the counter-current mechanism of transfer from the uteroovarian vein to the ovarian artery.10. Significantly higher concentrations of PGF₂α were found in the oviducal vein and the ovarian vein as well as in the uterine vein when compared to peripheral levels. Thus the alternative route is probably via the oviducal vein and then by transfer from the ovarian vein to ovarian artery in the ovarian pedicle.11. Daily injection of progesterone to sheep was found to lead to accumulation of large amount of fluid rich in PGF₂α in the uterine lumen. Concentrations of PGF₂α higher than peripheral were also found in the uterine venous blood of these animals. These findings show that a high concentration of progesterone can cause PGF₂α release

    Studies on ovarian and uterine function in the mare

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    The submitted collection of papers represents iny work in the area of equine ovarian function and dysfunction. During spring transition, the endocrinological events responsible for recruitment of large anovulatory follicles appear to resemble recruitment of preovulatory follicles in the natural breeding season. These large follicles contain only low concentrations of progesterone and oestradiol. They have low expression of rnRNA encoding steroidogenic enzymes, have poor development of the tlieca interna and are poorly vascularised. These follicles are therefore showing signs of atresia while they are actively increasing in size. In preovulatory follicles, concentrations of inflammatory mediators increase as ovulation approaches, and fluid from preovulatory follicles is chemotactic for leucocytes. Intrafollicular treatment with indomethacin delayed ovulation which supports the central role for inflammation in the ovulatory process. It is also likely the matrix metalloproteinases are involved in the profound tissue remodelling that occurs around ovulation. Control of follicular growth has been studied and equine follicles are dependent on gonadotrophin stimulation when they reach 10 mm in diameter and on LH stimulation for final growth and maturation.The equine CL is dependent, at least in part, on trophic support by LH and luteal cells bind LH in vitro. Steroidogenesis in the CL varies before and after development of the endometrial cups in pregnancy. StAR protein increases after endometrial cup formation, allowing greater mobilisation of substrate for steroid synthesis. Although P450arom is consistently present in the equine CL, P450C17 increases after the endometrial cups form, allowing oestrogen synthesis by the CL in the pregnant mare. The cell types in the equine CL appear to cooperate in steroidogenesis, with P450Cn located in small luteal cells, and P450arom in large luteal cells. Maintenance of the CL in early pregnancy appears to be caused by the inhibition of endometrial PG synthesis by the conceptus. although the conceptus itself produces PGs. The demise of the CL involves apoptosis and is preceded by a decrease in angiogenesis. The immune system appears to play a significant role, with an influx of CD8+ lymphocytes into the CL prior to functional regression. At this time also, the CL is producing substances chemotactic for immune cells.Endometritis is the commonest cause of subfertility in mares. Mares prone to endometritis have low myometrial contractility compared with reproductively-normal mares and this appears to be due to a defect in the uterine oxytocin receptor or post-receptor mechanisms. The uterus has also been shown to be a source of oxytocin with the hormone located in secretory vesicles of the epithelium of the lumen and superficial glands. In mares with chronic uterine infection, chemotactic factors are present in uterine fluid that enhance the migration of neutrophils into the uterine lumen. However uterine fluid from infected mares interferes with phagocytosis and the opsonic activity of specific antibodies in the fluid is lower than that from reproductively-normal mares. Apart from a possible relative deficiency in numbers of macrophages, no abnormalities were detected in the cellular immune system in mares prone to endometritis.REFERENCES: 2.1 Watson ED, Barbacini S, Berrocal B, Sheerin O, Marchi V, Zavaglia G and Neechi D (2001) Effect of insemination time of frozen semen on incidence of uterine fluid in mares Theriogenology 56 123 -131 Initiator ofwork with clinical assistance ‱ 2.2 Nikolakopoulos E and Watson ED (2002) Can uterine contractile activity be evaluated by transrectal ultrasonography? Theriogenology In Press Initiated work and supervised student ‱ 2.3 Sertich PL and Watson ED (1992) Plasma concentrations of 13,14-dihydro-15- ketoprostaglandin F2a in mares during uterine involution Journal of the American Veterinary Medical Association 201 434-437 Supervised Dr Sertich and technician ‱ 2.4 Watson ED, Buckingham J, Bjorksten TS and Nikolakopoulos E (2000) Immunolocalization of oxytocin and neurophysin in the mare uterus Journal of Reproduction and Fertility Supplement 56 289-296 Initiator and supervisor of work ‱ 2.5 Bae S-E and Watson ED (2000) Immunohistochemical localisation of oxytocin and neurophysin in the equine endometrium using transmission electron microscopy 14th International Congress on Animal Reproduction, Stockholm abstr 1:49 Initiator and supervisor of work ‱ 2.6 Nikolakopoulos E, Kindahl H, Gilbert CL and Goode J and Watson ED (2000) Release of oxytocin and PGF2a around teasing, natural service and associated events m the mare. Animal Reproduction Science 63 89-99 Initiator and supervisor ofwork. Prof Kindahl performed the PGFM assay. Dr Gilbert supervised the oxytocin assay ‱ 2.7 Nikolakopoulos E, Kindahl H and Watson ED (2000) Oxytocin and PGF2a release in mares resistant and susceptible to persistent mating-induced endometritis Journal of Reproduction and Fertility Supplement 56 363-372 Initiator and supervisor of work. ProfKindahl performed the PGFM assay ‱ 2.8 Bae S-E, Corcoran BM and Watson ED (2001) Organization of uterine innervation in the mare: distribution of immunoreactivities for the neuronal markers protein gene product 9.5 and PAN-N Equine Veterinary Journal 33 323-325 Initiator and cosupen'isor of work with Dr Corcoran ‱ 2.9 Bae S-E, Corcoran BM and Watson ED (2001) Immunohistochemical study of the distribution of adrenergic and peptidergic innervation in the equine uterus and the cervix Reproduction 122 275-282 Initiator and co-supervisor of work with Dr Corcoran ‱ 2.10 Nikolakopoulos E and Watson ED (1999) Uterine contractility is necessary for clearance of uterine fluid but not bacteria after bacterial infusion in the mare Theriogenology 52 413 -423 Initiator and supervisor of work ‱ 2.11 Nikolakopoulos E and Watson ED (1997) Does artificial insemination with chilled, extended semen reduce the antigenic challenge to the mare's uterus compared with natural service? Theriogenology 47 583-590 Initiator and supervisor of work ‱ 2.12 Nikolakopoulos E and Watson ED (2000) Effect of infusion volume and sperm numbers on persistence of uterine inflammation in mares Equine Veterinary Journal 32 164-166 Initiator and supervisor of work ‱ 2.13 Watson ED (2000) Post-breeding endometritis in the mare. Animal Reproduction Science 60-61 221-232 ‱ 2.14 Watson ED, Stokes CR, David JSE, Bourne FJ and Ricketts SW (1987) Concentrations of uterine luminal prostaglandins in mares with acute and persistent endometritis Equine Veterinary Journal 19 31 -37 My primary work with samples collected from cases by Mr Ricketts ‱ 2.15 Watson ED, Stokes CR and Bourne FJ (1987) Cellular and humoral defence mechanisms in mares susceptible and resistant to persistent endometritis Veterinary Immunology and Immunopathology 16 107-121 My primary work ‱ 2.16 Scudamore CL, Pemberton A, Miller HRP, McDonnell AM, Thomson SRM, Dawson A and Watson ED (1994) Measurement of equine alpha-1-proteinase inhibitor by ELISA in uterine flushings from mares Research in Veterinary Science 57 45-52 Supervised Dr Scudamore in collaboration with Professor Miller ‱ 2.17 Watson ED (1987) Uterine defence mechanisms in mares resistant and susceptible to persistent endometritis: A review Equine Veterinary Journal 20 397-400 ‱ 2.18 Watson ED and Dixon CE (1993) An immunohistological study of MHC Class II expression and of T lymphocytes in the endometrium of the mare Equine Veterinary Journal 25 120-124 My work with technical assistance ‱ 2.19 Watson ED and Thomson SRM (1996) Lymphocyte subsets in the endometrium of genitally-normal mares and mares susceptible to endometritis Equine Veterinary Journal 28 106-110 My work with technical assistance ‱ 2.20 Watson ED and Sertich PL (1992) Effect of repeated collection of multiple endometrial biopsy specimens on subsequent pregnancy in mares Journal of the American Veterinary Medical Association 201 438-440 My work with clinical assistance ‱ 2.21 Watson ED, Stokes CR and Bourne FJ (1987) The influence of administration of ovarian steroids on the function of neutrophils isolated from the blood and uterus of ovariectomized mares Journal ofEndocrinology 112 443-448 My primary work arising from my PhD ‱ 2.22 Watson ED, Stokes CR, David JSE and Bourne FJ (1987) Effect of ovarian hormones on promotion of bactericidal activity by uterine secretions of ovariectomized mares Journal ofReproduction and Fertility 79 531-537 My primary work arisingfrom my PhD ‱ 2.23 Watson ED, Stokes CR and Bourne FJ (1988) Effect of exogenous ovarian steroids on concentrations of uterine luminal prostaglandins in ovariectomised mares with experimental endometritis Research in Veterinary Science 44 361-365 My primary work arisingfrom my PhD ‱ 2.24 Watson ED, Stokes CR and Bourne FJ (1988) Influence of ovarian steroids on adherence (in vitro) of Streptococcus zooepidemicus to endometrial epithelial cells Equine Veterinary Journal 20 3 71 -3 72 My primary work ‱ 2.25 Watson ED and Stokes CR (1988) Plasma cell numbers in uteri of mares with persistent endometritis and in ovariectomised mares treated with ovarian steroids Equine Veterinary Journal 20 424-425 My primary work ‱ 2.26 Watson ED, Stokes CR and Bourne FJ (1987) The influence of arachidonic acid metabolites in vitro and in uterine washings on migration of equine neutrophils under agarose Research in Veterinary Science 43 203-207 My primary work arising from my PhD ‱ 2.27 Watson ED, Stokes CR and Bourne FJ (1988) Concentrations of immunoreactive leukotriene B-4 in uterine lavage fluid from mares with experimentally-induced and naturally occurring endometritis Journal of Veterinary Pharmacology and Therapeutics 11 130-134 My primary work ‱ 2.28 Scudamore CL, Pemberton A, Watson ED and Miller HRP (1993) Neutrophil chemotaxis in the horse is not mediated by a complex of equine neutrophil elastase and equine a-1-proteinase inhibitor British Veterinary Journal 149 331-338 Supervised Dr Scudamore in collaboration with Professor Miller ‱ 2.29 Watson ED (1988) Opsonins in uterine washings influencing in vitro activity of equine neutrophils Equine Veterinary Journal 20 435-437 My primary work ‱ 2.30 Watson ED and Stokes CR (1990) Effect of susceptibility to endometritis on specific antibody in the endometria of mares Theriogenology 34 39-45 My primary work ‱ 2.31 Watson ED and Stokes CR (1988) Use of hyperimmune serum in treatment of endometritis in mares Theriogenology 30 893-900 My primary work ‱ 2.32 Watson ED and Stokes CR (1988) Macrophage clearance of 125j_]abejie(j polyvinvyl pyrrolidone in the horse: Effect of ovarian steroids and persistent endometritis Equine Veterinary Journal 20 421-423 My primary work supervised by Professor Stokes ‱ 2.33 Summerfield N and Watson ED (1998) Endometrial macrophage populations in genitally normal mares at oestrus and dioestrus and in mares susceptible to endometritis Equine Veterinary Journal 30 79-81 My work with technical assistance ‱ 2.34 McDonnell AM and Watson ED (1993) The effect of dexamethasone sodium phosphate on mares with experimentally-induced endometritis Journal Equine Veterinary Science 13 202-206 Initiated and supennsed work ‱ 2.35 Tomanelli RN, Sertich PL and Watson ED (1991) Soluble oestrogen and progesterone receptors in the endometrium of the mare Journal ofReproduction and Fertility Supplement 44 267-273 Initiated and supen'ised laboratory work by Ms Tomanelli. Clinical assistance from Dr Sertich ‱ 2.36 Watson ED, Skolnik SB and Zanecosky HG (1992) Progesterone and estrogen receptor distribution in the endometrium of the mare Theriogenology 38 575-580 My work with technical assistance ‱ 2.37 McDonnell AM and Watson ED (1992) The effect of transcervical uterine manipulations on establishment of uterine infection in mares under the influence of progesterone Theriogenology 38 945-950 Initiated and supervised work by Ms McDonnell ‱ 2.38 Pedersen HG and Watson ED (2000) Uterine inflammation after intrauterine infusion with a low volume of Utrin Equine Veterinary Education 12 29-31 Initiator and supervisor of wor

    Escherichia coli : host interactions in the pathogenesis of canine pyometra

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    Tese de Doutoramento em CiĂȘncias VeterinĂĄrias na Especialidade de CiĂȘncias BiolĂłgicas e BiomĂ©dicasCanine pyometra develops as a result of a complex interaction of etiological and physiopathological factors, such as the virulence and type of the bacteria and the individual host defence mechanisms. Since Escherichia coli is the most common bacterium isolated from uterus of bitches with pyometra, one main objective of this work was to characterize E. coli virulence potential, and to evaluate the role of its virulence factors (VF) and traits in the pathogenesis of canine pyometra (Chapters IV, V and VI). A second main objective was to evaluate the innate immune mechanisms within the uterus and their role in E. coli recognition (Chapters III and VI). Results indicate that: i) although no single VF genes or virulence traits were associated with E. coli pyometra isolates, these isolates were mainly from the highly virulent phylogenetic group B2, which are characterized by a high number of uropathogenic E. coli VF genes and pathogenicity-associated islands markers; ii) Toll-like receptors were involved in the activation of the inflammatory response associated with pyometra; iii) ÎČ-hemolytic E. coli infection was associated with the occurrence of metritis and with an higher uterine tissue damage; iv) α-hemolysin (HlyA) contributes to the virulence of ÎČ-hemolytic E. coli, by inducing endometrial epithelial and stromal damage and a compromised early uterine immune response. Overall, these findings provide new relevant insights into the role of the pathogen-specific modulation of host immunity, which may influence the severity of disease and its clinical outcomes. Also, HlyA is a promising target for a vaccine, with the objective to induce an immunity that can block the binding and action of this toxin.RESUMO - InteracĂŁo hospedeiro-Escherichia coli na patogenia da piĂłmetra na cadela - A piĂłmetra Ă© uma doença comum do trato genital de cadelas adultas, durante a fase de diestro. A piĂłmetra desenvolve-se como resultado de uma complexa interação de fatores etiolĂłgicos e fisiopatolĂłgicos. Entre estes, incluem-se a influĂȘncia hormonal no Ăștero, alteraçÔes estruturais no endomĂ©trio - como a hiperplasia quĂ­stica (HQE) -, o tipo de bactĂ©rias e o seu potencial de virulĂȘncia, e os mecanismos de defesa do hospedeiro. O trabalho desenvolvido nesta tese baseou-se no estudo do potencial de virulĂȘncia de Escherichia coli (E. coli) (CapĂ­tulos IV e V) e nos mecanismos de imunidade inata do Ăștero (CapĂ­tulos III e VI). Tendo em conta a elevada prevalĂȘncia de E. coli nos casos de piĂłmetra (82-100% dos casos) e nas infeçÔes do trato urinĂĄrio (54 – 68%) e o facto de aquelas estirpes serem provenientes da flora fecal do animal e nĂŁo de um clone especĂ­fico disseminado entre animais, procedeu-se Ă  comparação do potencial de virulĂȘncia de E. coli, isolada de piĂłmetra, de cistites e de fezes de cadela (CapĂ­tulo IV). Os resultados indicam que as estirpes de E. coli, que colonizam o Ăștero, tĂȘm um elevado potencial de virulĂȘncia, possuindo um grande nĂșmero de genes que codificam para fatores de virulĂȘncia (FV) e ilhas de patogenicidade (PAIs). No entanto, existem estirpes de E. coli isoladas de cistite e de origem fecal com as mesmas caracterĂ­sticas, o que sugere que poderĂŁo induzir piĂłmetra, em cadelas suscetĂ­veis. De particular importĂąncia, foi a observação de que cerca de 50% das estirpes de E. coli isoladas de piĂłmetra eram ÎČ- hemolĂ­ticas. A prevalĂȘncia dos isolados pertencentes ao grupo filogenĂ©tico B2 foi maior nos casos de piĂłmetra (94%) do que nos casos de cistite (48%) ou do que nos de origem fecal (39%). No entanto, independentemente da origem dos isolados, o nĂșmero mĂ©dio de PAIs e de genes que codificam para FV foi maior nos isolados pertencentes ao grupo filogenĂ©tico B2, comparativamente aos outros grupos filogenĂ©ticos. Verificou-se tambĂ©m que o reto poderĂĄ funcionar como um reservatĂłrio de estirpes potencialmente patogĂ©nicas dos grupos filogenĂ©ticos B2 e D. Esta observação tem especial importĂąncia pois sabe-se que as estirpes de E. coli uropatogĂ©nicas isoladas de cĂŁes e humanos sĂŁo similares em relação ao seu serotipo, tipo clonal, grupo filogenĂ©tico e perfil de virulĂȘncia. Isto sugere que os cĂŁes podem servir como reservatĂłrios de bactĂ©rias potencialmente virulentas que podem ser transmitidas ao homem. Na primeira semana pĂłs-parto, E. coli Ă© a bactĂ©ria mais frequentemente isolada do conteĂșdo uterino de vacas de leite que desenvolvem infeçÔes uterinas puerperais. No entanto, a associação, entre o perfil de virulĂȘncia de E. coli e o desenvolvimento de metrite puerperal ou clinica, Ă© controverso e, em muitos dos casos, a infeção resolve-se espontaneamente. Na cadela, as piĂłmetras por E. coli estĂŁo associadas, em 50% dos casos, Ă  sĂ­ndrome de resposta inflamatĂłria sistĂ©mica, a qual Ă© potencialmente letal na ausĂȘncia de terapĂȘutica adequada. Numa tentativa de relacionar o potencial de virulĂȘncia de E. coli com as diferentes evoluçÔes da metrite clinica na vaca e da piĂłmetra na cadela, compararam-se caracterĂ­sticas genĂłmicas dos isolados de E. coli (CapĂ­tulo V). Os resultados mostram que as estirpes de E. coli isoladas de vacas com metrite clinica pertencem maioritariamente aos grupos filogenĂ©ticos B1 e A, sĂŁo geneticamente distintas das estirpes de piĂłmetra e apresentam um menor nĂșmero de genes que codificam para fatores de virulĂȘncia, sendo por isso consideradas estirpes de menor potencial de virulĂȘncia. A resposta uterina Ă  infeção Ă© composta por mecanismos da imunidade inata e adaptativa. A resposta inata Ă© desencadeada pelo reconhecimento de padrĂ”es moleculares associados aos agentes patogĂ©nicos, por recetores do tipo Toll (TLRs), induzindo uma reacção inflamatĂłria. Os resultados apresentados no CapĂ­tulo III permitem concluir que o Ăștero da cadela tem capacidade de reconhecer uma grande variedade de ligandos - atravĂ©s da activação dos TLRs - e desenvolver uma resposta inflamatĂłria contra vĂĄrios tipos de microorganismos. Verificouse, tambĂ©m, que a transcrição e expressĂŁo dos TLRs 2 e 4 encontram-se significativamente diminuĂ­das no inĂ­cio de diestro, o que pode contribuir para a maior susceptibilidade do Ăștero Ă  infeção por E. coli, nesta fase. Os resultados apresentados no CapĂ­tulo VI demonstram que, nos casos de piĂłmetra a resposta inflamatĂłria, mediada pelos TLRs, foi caracterizada por uma reação inflamatĂłria exuberante, demonstrada pelo influxo de cĂ©lulas de reação inflamatĂłria no Ăștero e por um aumento na transcrição de genes que codificam para citocinas prĂłinflamatĂłrias (IL-1ÎČ, IL-6, IL-8) e anti-inflamatĂłrias (IL-10 e TGFÎČ). Observação relevante foi que, nos casos de piĂłmetra por E. coli ÎČ-hemolĂ­tica, hĂĄ um aumento significativo da ..

    Protein involvement in prostaglandin production by the guinea-pig uterus

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    Priming with Oral Progestin Before Ovulation Induction Facilitates Ovarian Function in the Cat (Felis catus)

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    Artificial insemination (AI) has been developed in multiple felid species as a tool for retaining gene diversity in threatened or endangered populations. Yet, pregnancy success remains low (< 5%) following AI in most felids, particularly in species that spontaneously ovulate. This failure has been attributed to variable ovarian status at the time of insemination and adverse residual effects caused by exogenous gonadotropins used to induce ovulation. Using the domestic cat as a research model, a new AI regimen that incorporated short-term ovarian suppression with oral progestin (altrenogest; ALT) before ovulation induction was investigated. The hypothesis was that oral progestin priming would prevent spontaneous ovulation, improve ovarian responsiveness to exogenous gonadotropins and mitigate adverse effects caused by persistent gonadotropin actions. Specific objectives were to: (1) increase fundamental understanding of the mechanisms controlling ovarian function; and (2) characterize how oral progestin priming prior to exogenous gonadotropin treatment influences ovarian responsiveness, fertilization, early embryonic development and luteal function in the cat. Fecal hormone monitoring was used to establish an ALT dosage that provides rapid, reversible ovarian suppression with no residual effects on estrous cyclicity. With this information, the influence of progestin priming on ovarian responsiveness to exogenous gonadotropin dosage was investigated. Priming increased ovarian sensitivity to gonadotropins, supporting the use of lower dosages for ovulation induction. Next, in vivo fertilization success and in vitro early embryonic development was characterized following laparoscopic, intrauterine AI in cats treated with ALT. Progestin-primed females demonstrated a good ovarian response to ovulation induction and more consistent embryonic development, compared to cats treated with gonadotropins alone. Furthermore, endocrine data revealed that normal luteal progesterone levels were maintained only in queens primed with the oral progestin. Finally, histology and quantitative RT-PCR were used to characterize the differential effects on luteal function observed. Aberrant CL progesterone production was not associated with changes in ovarian morphology, or the expression of six specific genes associated with luteal function and progesterone biosynthesis. Overall, these studies increased knowledge of domestic cat reproductive physiology and improved understanding of ovarian suppression for enhanced AI efficiency in felids

    Bovine pre-transfer endometrium and embryo transcriptome fingerprints as predictors of pregnancy success after embryo transfer

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    Aberrant endometrial and embryonic gene expression is one of the causes of pregnancy failure in cattle. However, selecting cows with adequate endometrial receptivity and embryos of higher developmental competence based on the gene expression pattern has been a greater challenge. To investigate whether the pre-transfer endometrial and embryonic gene expression pattern has a direct relation with upcoming pregnancy success, a global endometrial and embryonic transcriptome analysis was carried out in endometrial and embryo biopsy samples using GeneChipÂź Bovine Genome Array and preimplantation specific cDNA array, respectively. For this, endometrium biopsies were taken at days 7 and 14 of the estrous cycle in Simmental heifers during the pre-transfer period. In the next cycle, in vivo produced day 7 blastocysts were transferred to the recipients at day 7 of the estrous cycle after taking 30-40% parts of the blastocyst as a biopsy for transcriptome analysis. After pregnancy diagnosis, the heifers were classified as calf delivery (receptive endometrium) and no pregnancy (non-receptive endometrium) groups. Subsequently, the endometrial biopsies (taken at days 7 and 14 of the estrous cycle) and the embryo biopsies were categorized as calf delivery or no pregnancy groups. The results revealed 1126 genes were differentially expressed between receptive and non-receptive endometrium at day 7 of the estrous cycle. These differences were accompanied by qualitative and quantitative alteration of major biological process and molecular pathways including cellular localization, post-transcriptional modification, signal transduction, apoptosis, cell cycle and immune response. However, only 14 genes were differentially expressed between receptive and non-receptive endometrium at day 14 of the estrous cycle. Furthermore, the transcriptome dynamics of receptive and non-receptive endometrium between day 7 and 14 of the estrous cycle revealed 1867 and 254 differentially expressed genes, respectively. The higher number of differentially expressed genes and functional categories between day 7 and 14 of the estrous cycle in receptive compared to non-receptive endometrium revealed the transcriptome plasticity of receptive endometrium. In addition, the gene expression profile in embryos biopsies resulted in calf delivery and those resulted in no pregnancy revealed 70 genes to be differentially expressed between the two embryo groups. Among those, 32 genes including SPAG17, PF6, UBE2D3P, DFNB31, AMD1, DTNBP1 and ARL8B were elevated in calf delivery groups and 38 genes including SGK1, GBF1, KRT8, DTX2, RNF34, ARL8B, RYBP and EEF1 were elevated in no pregnancy embryo groups. Therefore, the present study highlights the potential of pre-transfer endometrial and embryonic gene expression patterns as predictors of pregnancy success in cattle.Genexprssionsprofile von vor dem Transfer biopsierten bovinen Endometrien und Embryonen als PrĂ€dikator fĂŒr den TrĂ€chtigkeitserfolg beim Rind Abweichende Genexpressionen sowohl des Embryos als auch des Endometriums sind ein Grund fĂŒr verminderte TrĂ€chtigkeitsraten nach dem Embryotransfer beim Rind. Die Selektion der Embryonen einerseits und der EmpfĂ€ngertiere an Hand des Endometriums andererseits basierend auf den Genexpressionsmustern, stellt eine große Herausforderung dar. Um herauszufinden, ob Korrelationen zwischen der Genexpression des Endometriums vor dem Transfer und der des Embryos auf der einen Seite und einer erfolgreichen TrĂ€chtigkeit auf der anderen Seite, vorliegen, wurde eine globale Transkriptionsanalyse der Biopsien des Endometriums und des Embryos mittels des GeneChipÂź Bovine Genome Array und einem prĂ€implantations spezifischen cDNA Arrays durchgefĂŒhrt. Die Biopsieproben des Endometriums wurden an Tag 7 und Tag 14 des Vorzykluses der Versuchstiere (Simmental FĂ€rsen) genommen. Des Weitern wurden in vivo Blastozysten am Tag 7 gespĂŒlt, eine Biopsieprobe genommen (ca. 30-40%) und die Embryonen auf die EmpfĂ€ngertiere ĂŒbertragen. Diese Biopsieproben wurden nach der TrĂ€chtigkeitsuntersuchung den Gruppen der trĂ€chtigen FĂ€rsen (rezeptives Endometrium) und der nicht-trĂ€chtigen FĂ€rsen (nicht-rezeptives Endometrium) zugeordnet. Insgesamt wurden 1126 unterschiedlich exprimierte Gene zwischen den rezeptiven und nichtrezeptiven Endometrien an Tag 7 detektiert. Des Weiteren zeigten sich qualitative und quantitative VerĂ€nderungen in bedeutenden biologischen Prozessen und molekularen Pathways, wie in der zellulĂ€ren Anordnung, posttranskriptionalen Modifikation, Signaltransduktion, Apoptose, im Zellzyklus und in der Imunantwort. KontrĂ€r zu diesen Ergebnissen waren an Tag 14 nur 14 Gene zwischen den Endometrien unterschiedlich reguliert. Im Bereich der Transkriptionsdynamik waren zwischen den Gruppen an Tag 7 1867 Gene und am Tag 14 254 Gene unterschiedlich exprimiert. Diese relativ große Anzahl unterschiedlich regulierter Gene zeigt die TranskriptomplastizitĂ€t des rezeptiven Endometriums. Zwischen den Biopsieproben der Embryonen, die zu einer TrĂ€chtigkeit fĂŒhrten und denen die keine TrĂ€chtigkeit induzierten zeigten 70 Gene eine unterschiedliche Expression. In der ersten Gruppe wurden 32 Gene, darunter SPAG17, PF6, UBE2D3P, DFNB31, AMD1, DTNBP1 und ARL8B expremiert und in der zweiten Gruppe 38 Gene darunter SGK1, GBF1, KRT8, DTX2, RNF34, ARL8B, RYBP und EEF1. Die vorliegende Arbeit zeigt demzufolge, dass das Genexpressionsprofil des Endometriums und der Embryonen vor dem Transfer als Vorhersage fĂŒr den TrĂ€chtigkeitserfolg dienen kann

    Reproductive Biology and Technology in Animals

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    Reproductive success is a very important objective to ensure the evolution of animal species. In this sense, interesting research has been carried out to clarify various aspects of reproduction in different animal species. In this way, recent advances in the knowledge of reproductive biology and biotechnology developed for both males and females have been key to improving efficiency in different aspects. Thus, advances in the knowledge of sperm handling, oocyte characteristics, different genomic aspects related to somatic cell nuclear transfer, and the reproductive microarchitecture system in sheep, cows, pigs, and other invertebrates such as gastropods and fish are presented in this book. Additionally, we also present the most relevant topics of each area, making a detailed review of the knowledge reported to date
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