Hormones of oestrus and ovulation and their manipulation in marsupials

1996 ◽  
Vol 8 (4) ◽  
pp. 661 ◽  
Author(s):  
LA Hinds ◽  
TP Fletcher ◽  
JC Rodger

Oestrus and ovulation occur spontaneously in the majority of marsupials, with behavioural oestrus usually occurring 1-2 days before ovulation. The hormone changes that occur at this time have been described in the most detail for the monovular tammar wallaby Macropus eugenii. The respective roles of the Graafian follicle, corpus luteum and the pituitary in the events leading up to oestrus and ovulation in this species are also reviewed. Recently, various protocols have been developed for superovulation of marsupials, including Australian species, such as the brush-tailed possum, fat-tailed dunnart, brush-tailed bettong and tammar wallaby, and the American laboratory opossum, Monodelphis domestica. These protocols provide an opportunity for studying the regulation of ovarian activity and for the collection of larger quantities of material for the study of gamete maturation, in vitro fertilization and embryonic development.


Author(s):  
O. M. Sharan ◽  
V. Yu. Stefanyk ◽  
S. G. Shalovylo

New literature data on research aimed at improving the in vitro production of sheep embryos presents in the article. An analysis of the achievements of scientists from different countries to increase the efficiency of the main stages of embryo production in vitro: maturation of oocytes in vitro, their in vitro fertilization and in vitro embryo culture. In the literature experience has shown that the efficiency of oocyte maturation in vitro is significantly influenced by the experience and qualifications of scientists, the age of the egg donor, the improvement of the environment by adding roscovitin to inhibit meiosis, α-linolenic acid, cerium dioxide nanoparticles (CeO2 NPs) and sericin to accelerate nuclear maturation and increase the number of oocytes of the second meiotic metaphase (MII). The main factors influencing the effectiveness of in vitro fertilization have been identified, and the parameters of the limited time of fertilization ability of sperm and the ability of oocytes to fertilize, which is called the “fertile span”, have been determined. The main effective medium that increases the effectiveness of in vitro fertilization – synthetic oviduct fluid (SOF) with the addition of heparin and serum of cattle or sheep. The main parameters of sheep embryo culture in vitro are presented with the definition of the most commonly used media and their influence on embryonic development. Potential ways to improve the production of sheep embryos in vitro with the determination of morphological evaluation of categories of oocytes, methods of synchronization of their maturation in vitro are also highlighted. At the same time, literature data on the synchronization of oocyte-cumulus complexes with the use of a large number of inhibitors of meiotic division are presented, which according to many scientists may be a key factor in improving the efficiency of sheep embryo production in vitro. In addition, the results of studies of many scientists on the expansion of the fertile gap of oocytes of sheep cultured in vitro using certain biologically active substances were analyzed. In conclusion, the prospect of using the technology of in vitro production of sheep embryos in biomedical research is highlighted.





2004 ◽  
Vol 17 (1) ◽  
pp. 33-38
Author(s):  
H. Y. Jang ◽  
H. S. Kong ◽  
S. S. Lee ◽  
K. D. Choi ◽  
G. J. Jeon ◽  
...  


1996 ◽  
Vol 8 (4) ◽  
pp. 681 ◽  
Author(s):  
FC Molinia ◽  
JC Rodger

A protocol was developed for pellet-freezing spermatozoa of the tammar wallaby and the brushtail possum. Seren was collected by electro-ejaculation and wallaby spermatozoa were washed by 'swim-up' into phosphate-buffered saline (PBS), whereas possum spermatozoa were not washed. Wallaby spermatozoa were screened for toxicity in diluents containing a range of cryoprotectants (0-10%): dimethyl sulfoxide (DMSO), ethylene glycol and propanediol. Possum spermatozoa were tolerant of diluents containing 17.5% glycerol. Wallaby and possum spermatozoa were diluted 1:1 with the most promising cryoprotective diluents (final concentrations in PBS: possum, 17.5% glycerol; wallaby, 7.5% glycerol + 10% DMSO) and, after 5 min equilibration at room temperature, were pellet-frozen. Pellets were thawed (35 degrees C) and wallaby spermatozoa were washed by centrifugation (200 g for 5 min) and resuspended in PBS to minimize cryoprotectant toxicity. A high proportion of possum spermatozoa was recovered after freezing (67.5%), having good progressive motility (3.6 on a 0-5 scale). The progressive motility of frozen-thawed wallaby spermatozoa was also high (3.0), but only 10% of motile spermatozoa were recovered. The pellet-freezing method in conjunction with the post-thaw washing procedure (wallaby) may produce a viable population of cryopreserved marsupial spermatozoa suitable for use in assisted-breeding techniques such as in vitro fertilization and artificial insemination.



2019 ◽  
pp. 17-19
Author(s):  
G.N. SINGINA ◽  
V. HAVLICEK ◽  
N.P. TARADAYNIK ◽  
R.Y. CHINAROV ◽  
T.E. TARADAYNIK ◽  
...  

Представлены результаты трансвагинальной аспирации ооцитов коров, а также оценен их потенциал к эмбриональному развитию после оплодотворения в условиях in vitro. Донорами яйцеклеток являлись половозрелые телки симментальской породы в возрасте 1619 мес. Животныедоноры (n7) перед проведением процедуры Ovum Pickup (OPU) были гормонально обработаны с целью стимуляции роста фолликулов. Количество выделенных ооцитов от индивидуальных доноров составило в среднем 7,7 ооциткумулюсных комплексов (ОКК), что соответствовало степени извлечения 54,57,7. Доля ОКК хорошего качества, рассчитанная от общего числа извлеченных ОКК, между отдельными животными существенно не различалась (значения варьировали от 60,0 до 75,0) и в среднем составила 67,21,9. ОКК с признаками нормальной морфологии подвергали in vitro процедурам созревания, оплодотворения и последующего культивирования до стадии бластоцисты. Доля раздробившихся ооцитов и выход бластоцист после in vitro осеменения яйцеклеток коров равнялась 75,7 и 24,3, соответственно. В целом от одного донора за сессию OPU было получено 1,3 эмбриона на стадии бластоцисты, содержащих в среднем 89,8 ядра. Оцененный способ экстракорпорального оплодотворения OPUооцитов коров позволяет получать эмбрионы, пригодные для замораживания и трансплантации реципиентам и может быть использован в программах по воспроизводству желаемых генотипов у крупного рогатого скота.In the present work, we report the data on transvaginal aspiration of bovine ovarian follicles and estimation of in vitro embryo development competence of collected oocytes. The oocytes were collected by ovum pickup OPU from seven 1619 monthold Simmental heifers, previously hormonallytreated in order to stimulate ovarian follicular growth. In average, 7.7 oocytecumulus complexes (OCCs) per heifer per OPU session were collected that corresponded to 54.57.7 of recovery rate. Morphologically, 60.075.0 of OCCs were the good quality and this rate did not significantly differ between the animals. Good quality OCCs (total n37) were then subjected to in vitro maturation, in vitro fertilization and in vitro embryo development up to blastocyst stage. Cleavage and blastocyst rates were 75.7 и 24.3 , respectively. In total, 1.3 blastocysts were obtained per cow per OPU session in average these blastocysts contained 89.9 cells. In conclusion, we developed the methodology of in vitro fertilization of bovine OPUcollected oocytes that allowed obtaining the blastocysts potentially suitable for freezing and transplantation to recipients. This approach can be used to multiply desired genotypes in cattle reproduction.





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