Abstract The aim of this trial was to evaluate the effect of embryo cryopreservation techniques on the survivability of embryos and fertility following transfer to Boer goat does. The oestrous cycles of 27 mature recipients Boer goat does were synchronised using controlled internal drug release dispensers (CIDR’s) for 16 days. At CIDR removal, does were injected with 300 IU eCG. The recipient does were allocated to 3 groups (n = 9 per group), based on the technique of cryopreservation used for the embryos transferred. The in vivo produced embryos used were at blastocyst stage and surgically collected on day 6 following AI from Boer goat donors superovulated with pFSH. The first group received fresh embryos and served as the control, the second group of does received conventional slow frozen/thawed embryos and the third group received vitrified/thawed embryos. Two blastocysts were transferred per doe. A pregnancy rate of 85.7% (n = 6) was obtained following the transfer of fresh embryos and tended to be better than in does receiving slow frozen and vitrified embryos, (n = 4; 50.0% and n = 3; 37.5% does pregnant, respectively). The overall gestation period recorded for all does was 146.3 ± 3.0 d, with an overall litter size of 1.7 ± 0.5 being recorded. The kidding rate of the recipient does declined to 57.0% (4) and 25.0% (2) for fresh and conventional slow frozen groups, respectively. An embryo survival rate of 35.7% (n = 5) for fresh, 25.0% (n = 4) for conventional slow freezing and 31.3% (n = 5) for vitrification was recorded and was not affected by the number of CL’s present on the respective ovaries at the time of transfer. There was a tendency for more females to be born than males (ratio 1 : 2, male : female) but this could not be related to the cryopreservation technique. Although the pregnancy rate following the transfer of fresh embryos was satisfactory, the embryo survival rate following the transfer of either fresh or cryopreserved embryos tended to be less acceptable. More research is warranted with larger numbers of animals, directed at improving the survivability of embryos following fresh and cryopreserved goat embryo transfer.

Abstract The aim of this trial was to evaluate the effect of embryo cryopreservation techniques on the survivability of embryos and fertility following transfer to Boer goat does. The oestrous cycles of 27 mature recipients Boer goat does were synchronised using controlled internal drug release dispensers (CIDR’s) for 16 days. At CIDR removal, does were injected with 300 IU eCG. The recipient does were allocated to 3 groups (n = 9 per group), based on the technique of cryopreservation used for the embryos transferred. The in vivo produced embryos used were at blastocyst stage and surgically collected on day 6 following AI from Boer goat donors superovulated with pFSH. The first group received fresh embryos and served as the control, the second group of does received conventional slow frozen/thawed embryos and the third group received vitrified/thawed embryos. Two blastocysts were transferred per doe. A pregnancy rate of 85.7% (n = 6) was obtained following the transfer of fresh embryos and tended to be better than in does receiving slow frozen and vitrified embryos, (n = 4; 50.0% and n = 3; 37.5% does pregnant, respectively). The overall gestation period recorded for all does was 146.3 ± 3.0 d, with an overall litter size of 1.7 ± 0.5 being recorded. The kidding rate of the recipient does declined to 57.0% (4) and 25.0% (2) for fresh and conventional slow frozen groups, respectively. An embryo survival rate of 35.7% (n = 5) for fresh, 25.0% (n = 4) for conventional slow freezing and 31.3% (n = 5) for vitrification was recorded and was not affected by the number of CL’s present on the respective ovaries at the time of transfer. There was a tendency for more females to be born than males (ratio 1 : 2, male : female) but this could not be related to the cryopreservation technique. Although the pregnancy rate following the transfer of fresh embryos was satisfactory, the embryo survival rate following the transfer of either fresh or cryopreserved embryos tended to be less acceptable. More research is warranted with larger numbers of animals, directed at improving the survivability of embryos following fresh and cryopreserved goat embryo transfer.

Made available in DSpace on 2014-06-11T19:29:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-07-20Bitstream added on 2014-06-13T18:39:05Z : No. of bitstreams: 1 perini_ap_me_jabo.pdf: 340824 bytes, checksum: 06eec48bbcaca721eb390ec701442f6b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho teve como objetivos separar os espermatozóides portadores do cromossomo X viáveis, dos portadores do Y, através de gradiente descontínuo de densidade de PercollTM. Utilizar esse sêmen na produção in vitro de embriões bovinos, substituindo o SFB pela BSA no cultivo. Congelar estes embriões pelo método da congelação lenta. Avaliar a criotolerância dos embriões do sexo feminino pela taxa de eclosão e a eficiência do gradiente pela técnica da PCR, que identificou o sexo dos embriões produzidos. Foram produzidos 133 embriões do tratamento sexado (embriões produzidos a partir de sêmen submetido ao gradiente de densidade de PercollTM) e 100 do tratamento controle (embriões produzidos de acordo com o protocolo utilizado no departamento de Reprodução Animal). Após congelação, descongelação e cultivo destes embriões apenas 8 eclodiram do tratamento sexado e também 8 do tratamento controle, a análise estatística deste resultado demonstrou que o sexo não influenciou na taxa de eclosão pós descongelação. Porém a análise estatística dos embriões produzidos com sêmen sexado e submetidos a PCR demonstrou que o gradiente de densidade de PercollTM foi eficaz na separação dos espermatozóides X viáveis em 62%. / The present study had as purposes to separe X and Y sperm by PercollTM descontinuous density gradient. Use the semen on in vitro production bovine embryos, replacing the BFS for BSA on the culture. To freezing the embryos by the slow curve method. Evaluate the female embryos cryotolerance by eclosion rate and the gradient eficience by PCR technique that identify the embryos sex. 133 embryos were produced by the sexed treatment and 100 by control treatment. After freezing, unfreezing and culture of the embryos, only 8 ecloded of each treatment, the result statistics analyses showed that the sex had no influence on the eclosion rate after unfreeze. However the statistics analyses of the sexed semen produced embryos and submitted to PCR showed that the PercollTM density gradient was efficient on the viable X separation sperm in 62%.

Orientador: Vera Fernanda Martins Hossepian de Lima / Banca: Wilter Ricardo Russiano Vicente / Banca: Elmo Gomes Diniz / Resumo: O presente trabalho teve como objetivos separar os espermatozóides portadores do cromossomo X viáveis, dos portadores do Y, através de gradiente descontínuo de densidade de PercollTM. Utilizar esse sêmen na produção in vitro de embriões bovinos, substituindo o SFB pela BSA no cultivo. Congelar estes embriões pelo método da congelação lenta. Avaliar a criotolerância dos embriões do sexo feminino pela taxa de eclosão e a eficiência do gradiente pela técnica da PCR, que identificou o sexo dos embriões produzidos. Foram produzidos 133 embriões do tratamento sexado (embriões produzidos a partir de sêmen submetido ao gradiente de densidade de PercollTM) e 100 do tratamento controle (embriões produzidos de acordo com o protocolo utilizado no departamento de Reprodução Animal). Após congelação, descongelação e cultivo destes embriões apenas 8 eclodiram do tratamento sexado e também 8 do tratamento controle, a análise estatística deste resultado demonstrou que o sexo não influenciou na taxa de eclosão pós descongelação. Porém a análise estatística dos embriões produzidos com sêmen sexado e submetidos a PCR demonstrou que o gradiente de densidade de PercollTM foi eficaz na separação dos espermatozóides X viáveis em 62%. / Abstract: The present study had as purposes to separe X and Y sperm by PercollTM descontinuous density gradient. Use the semen on in vitro production bovine embryos, replacing the BFS for BSA on the culture. To freezing the embryos by the slow curve method. Evaluate the female embryos cryotolerance by eclosion rate and the gradient eficience by PCR technique that identify the embryos sex. 133 embryos were produced by the sexed treatment and 100 by control treatment. After freezing, unfreezing and culture of the embryos, only 8 ecloded of each treatment, the result statistics analyses showed that the sex had no influence on the eclosion rate after unfreeze. However the statistics analyses of the sexed semen produced embryos and submitted to PCR showed that the PercollTM density gradient was efficient on the viable X separation sperm in 62%. / Mestre

The general aim of this thesis was to optimise the current methodologies of oocyte cryopreservation in order to obtain live offspring from cryopreserved rabbit oocytes. In chapter 1, meiotic spindle configuration, cortical granules (CGs) distribution and oocyte developmental competence were evaluated after cryopreservation with the current slow-freezing and vitrification procedures. The meiotic spindle organisation was dramatically impaired regardless of the method used. Nevertheless, altered CG distribution is more evident in vitrified oocytes than in slow-frozen ones and the developmental rate to blastocyst stage after parthenogenetic activation was only obtained using slow-freezing method. From this chapter it may be concluded that both methodologies equally affect oocyte structure. However, slow-freezing method seems to be the recommended option for this species as a consequence of the sensitivity to high levels of cryoprotectants in this species. The aim of the following two chapters was the optimisation of cryopreservation procedures using different strategies to modify the oocytes in order to make them more cryoresistant. In chapter 2, Taxol and Cytochalasin B were employed to stabilise the cytoskeleton system during vitrification. The effect of these two molecules on the meiotic spindle and chromosome configuration and development to blastocyst stage after parthenogenesis activation were also evaluated. There were no significant differences in the structural configuration between vitrified groups. Regarding cleavage and blastocyst developmental rate, no statistical differences were found between vitrified-non-treated and Taxol-treated oocytes, but no oocytes treated with Cytochalasin B reached this stage. Therefore, structural configuration and blastocyst development were not improved by this pre-treatment. Moreover, Cytochalasin B pre-treatment seems to cause a deleterious effect on developmental ability to blastocyst stage of these oocytes. In chapter 3, oocytes were incubated with cholesterol-loaded methyl-ß- cyclodextrin (CLC) to increase the membrane fluidity and stability and improve their developmental ability after parthenogenetic activation or intracytoplasmic sperm injection (ICSI). Cholesterol incorporation and its presence after cryopreservation were evaluated using confocal microscopy. Results showed that cholesterol was incorporated into the oocyte and remained, albeit in a lesser amount after cryopreservation procedures. However, no improvements on developmental competence were obtained after parthenogenetic activation or intracytoplasmic sperm injection. In the last three chapters of this thesis, the main objective was to develop a reliable technique which would allow us to obtain live offspring from cryopreserved oocytes. For that purpose, in vivo fertilisation using intraoviductal oocyte transfer assisted by laparoscopy was considered a good alternative to bypass the inadequacy of conventional in vitro fertilisation in rabbit. In chapter 4, two recipient models (ovariectomised or oviduct ligated immediately after transfer) were used to compare the ability of fresh oocytes to fertilise in vivo. This first work showed that embryo recovery rates in all transferred groups decreased significantly, but ligated oviduct recipients provided significantly higher results compared to ovariectomised ones. For that reason, in the second experiment the ligated oviduct recipient model was used to generate live births. Results obtained in this chapter suggested that it was possible to obtain offspring from cryopreserved oocytes using this technique, but this kind of animal models compromised the use of the reproductive tract in a high percentage of females. For that reason, chapter 5 was focused on the development of another type of animal model as an alternative. First, the ability of cyanoacrylate tissue adhesive to block the oviducts before the ovulation would take place was evaluated. Then, in vivo fertilisation ability of fresh transferred oocytes after blocking the oviduct with the adhesive was also assessed. Finally, slow frozen oocytes were transferred to generate live birth. Results showed that cyanoacrylate tissue adhesive was effective in blocking the oviduct, as no embryos were recovered in the blocked oviduct six days after artificial insemination (AI). Moreover, this method could fertilise fresh and also slowfrozen oocytes with a higher live birth rate than the previous recipient models. This study showed that successful production of live offspring using slow-frozen oocytes in combination with in vivo fertilisation was possible, which suggested that in vivo environment could help improve the results of oocyte cryopreservation. Thus, this method was employed in the last chapter of this thesis to generate live offspring from vitrified rabbit oocytes for the first time. Results obtained revealed that there were no differences in the rate of birth between vitrified and slow-frozen transferred oocytes. Nevertheless, based on the results with fresh oocytes, further experiments are still needed if the efficiency of cryopreservation procedures are to be improved. / Jiménez Trigos, ME. (2014). Generation of offspring from cryopreserved rabbit (Oryctolagus cuniculus) oocytes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37977 / TESIS

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No. of bitstreams: 2 Tese - Tiago Omar Diesel - 2018.pdf: 2037910 bytes, checksum: e5037a6e126e6597f8f92b2754602731 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-13 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Chemical delipidation has been used as an alternative to improve the cryotolerance of in vitro produced embryos (IVP). The aim of this study was evaluate the effect of L-carnitine (LC) on the development and survival of vitrified IVP bovine embryos by the Cryotop method in the first assay, and in the second trial the effect of LC and Forskolin on Cryotop cryopreserved embryos Experiment 1), or by modified slow freezing (Experiment 2), so mitochondrial activity, intracytoplasmic lipid (LI) content, cellular apoptosis (NCA) and hatching after heating were evaluated. In the first essay LC was used at the concentration of 0,6 mg/mL in maturation culture medium (IVM), embryo culture (IVC) and / or post-thawing (REC), in four treatments: without LC (Control), LC added to CIV (LCiv), LC to CIV + LC to REC (LCivR), and LC to MIV / CIV + LC to REC (LMivCR). The addition of LC increased the production of blastocysts in D7 by 28.6% (LCiv) and the amount of embryos grade I by 36.9% (LCivR), the re-expansion rate in 22,7% and hatching in 20.1% (LCiv), and mitochondrial activity was 1.9 times higher (P <0.001) (LCivR) than Control. The LI quantity was 29% lower in LCiv and LCivR and 50.2% in LMivCR compared Control (P <0.001). In the second experiment the embryos were cultured without addition of delipidators (Control), in the presence of 10μM of Forskolin added to the IVC in D5 (FORSK) or L-carnitine (0.6 mg / mL) added to the IVC and in post-thawing (LC). LC supplementation increased the production of blastocysts in D7 by 22.0% and grade I embryos by 30.1% (P <0.05), in relation to Control and FORSK. In Experiment 1, the re-expansion rate in LC increased (P <0.05) 28.9% in relation to FORSK. In Experiment 2, two Control treatments were used for slow freezing (Classic and Modified). Hatching after 48 hours was greater (P <0.05) in LC compared to FORSK and Classical and Modified Controls (77.5%, 41.9%, 40.5%, 40.8% respectively). In the LC treatment, there was a decrease (P <0.05) of 64.7% in the degenerate embryo rate in relation to the Classical Control. Treatment with delipidators reduced LI content (P <0.001) by 2.2 fold in FORSK and four times in the LC compared to Control. The addition of 0.6 mg / mL of L-carnitine to the culture medium and the post-thawing increased the rate of in vitro production of bovine embryos acting positively on mitochondrial potential, reducing the amount of intracellular lipids and cellular apoptosis and increasing cryotolerance of embryos submitted to the modified slow freezing protocol. / A delipidação química tem sido utilizada como alternativa para a melhoria da criotolerância em embriões produzidos in vitro (PIV). Este estudo foi realizado objetivando avaliar o efeito da Lcarnitina (LC) sobre o desenvolvimento e a sobrevivência de embriões bovinos PIV vitrificados pelo método Cryotop no primeiro ensaio, e no segundo ensaio o efeito comparado da LC e Forskolin em embriões criopreservados por Cryotop (Experimento 1), ou por congelamento lento modificado (Experimento 2). Para isto foram avaliadas a atividade mitocondrial, o conteúdo de lipídeos intracitoplasmático (LI), a apoptose celular e a eclosão após o aquecimento. No primeiro ensaio a LC foi utilizada na concentração de 0,6 mg/mL no meio para maturação (MIV), cultivo (CIV) e/ou recultivo embrionário (REC), em quatro tratamentos: sem LC (Controle), LC adicionado ao CIV (LCiv), LC ao CIV+LC ao REC (LCivR), e LC ao MIV/CIV+ LC ao REC (LMivCR). A adição de LC aumentou (P <0,05) a produção de blastocistos em D7 em 28,6% (LCiv), a quantidade de embriões grau I em 36,9% (LCivR), a taxa de re-expansão em 22,7%, a eclosão em 20,1% (LCiv) e a atividade mitocondrial foi 1,9 vezes maior (P <0,001) (LCivR) em relação ao Controle. A quantidade LI foi 29% menor em LCiv e LCivR e 50,2% em LMivCR comparado Controle (P <0,001). No segundo ensaio os embriões foram cultivados sem adição de delipidadores (Controle), na presença de 10µM de Forskolin adicionado ao CIV no D5 (FORSK) ou L-carnitina (0,6 mg/mL) adicionada ao CIV e ao recultivo (LC). A suplementação com LC aumentou a produção de blastocistos em D7 em 22,0% e de embriões grau I em 30,1% (P <0,05), em relação ao Controle e ao FORSK. No Experimento 1 a taxa de re-expansão no LC aumentou (P <0,05) 28,9% em relação ao FORSK. No Experimento 2 foram utilizados dois tratamentos Controle para congelamento lento (Clássico e Modificado). A eclosão após 48 horas foi maior (P < 0,05) no LC em comparação ao FORSK e aos Controles Clássico e Modificado (77,5%, 41,9%, 40,5%, 40,8% respectivamente). No tratamento LC foi observada diminuição (P < 0,05) de 64,7% na taxa de embriões degenerados em relação ao Controle Clássico. O tratamento com delipidadores reduziu o conteúdo de LI (P < 0,001) em 2,2 vezes em FORSK e quatro vezes no LC comparados ao Controle. A adição de 0,6 mg/mL de L-carnitina aos meios de cultivo e recultivo aumentou a taxa de produção in vitro de embriões bovinos atuando positivamente sobre a atividade mitocondrial, reduzindo a quantidade de lipídeos intracelulares e a apoptose e aumentando a criotolerância dos embriões submetidos ao protocolo de congelamento lento modificado.

As técnicas de cultivo de folículos e oócitos in vitro, com o objetivo de se obter oócitos maduros para procedimentos de Reprodução Assistida (RA), têm sido aplicadas em diferentes contextos. O sucesso destes procedimentos está diretamente relacionado ao sistema de cultivo utilizado. A utilização de células da granulosa (CG) humanas cultivadas in vitro como um suporte para o co-cultivo destes oócitos imaturos e folículos tem sido descrita por alguns autores. A criopreservação destas células, considerando-se o contexto de sua obtenção em procedimentos de RA, permitiria a viabilização da aplicação destas células na prática clínica diária. Sendo assim, o objetivo deste estudo foi padronizar o congelamento de células da granulosa (CG) humanas para aplicação em sistemas de co-cultivos de folículos e oócitos imaturos. Foram obtidas CG de 20 voluntárias em tratamento de reprodução assistida, células de 10 voluntárias foram cultivadas em meio ?-MEM suplementado para interrupção da luteinização e congeladas após 48 horas em container \"Cryostep\" (grupo 2C- 2 cultivos) (etapa 2) e células de 10 voluntárias foram congeladas em container \"Cryostep\" sem cultivo prévio (grupo CD- congelamento direto) (etapa 3). Após o descongelamento estas células foram (re)cultivadas por 144 horas, com troca de meio em 48, 96 e 144 horas para avaliações da produção de estradiol (E2) e progesterona (P4) (ng/mL). Verificamos redução na contagem celular e na viabilidade celular tanto no método de congelamento direto (CD) quanto no método com dois cultivos (2C) após o descongelamento (p<0,05), e isso se refletiu na produção de estradiol e progesterona que foi maior nas culturas de células frescas em relação às células criopreservadas (p<0,05). Porém, a relação de E2/célula foi mantida após o descongelamento, sugerindo que esta redução na produção se deve à redução no número de células, as que sobrevivem se mantém normofuncionantes (p=0,23).O CD foi mais eficiente pois permitiu uma maior recuperação celular e uma melhor viabilidade quando comparado ao grupo 2C. A relação estradiol/progesterona foi mantida em todos os tempos de cultivo, fresco, CD e 2C (p>0,05), indicando que a característica funcional destas células foi preservada após o descongelamento. Concluímos que a criopreservação de CG humanas obtidas durante a captação de oócitos compromete a contagem celular e a viabilidade geral da cultura, entretanto, a capacidade funcional e a característica destas células se mantêm preservadas (manutenção das relações E2/célula e E2/P4) / Follicle and oocyte in vitro culture techniques, aiming to obtain mature oocytes for Assisted Reproductive Treatments (ART), have been applied to different contexts. The success of these procedures depends on the culture system used. The use of human granulosa cells (GC) in co-culture systems for follicle and oocyte maturation have been described by some authors. The cryopreservation of these cells, considering the context in which they are obtained during ART, would enable the usage of these cells in such procedures in daily clinical practice. Thus, the objective of this study was to standardize the freezing protocol for human granulosa cells (GC) for future applications in co-culture systems for follicle and oocyte maturation. Twenty volunteers submitted to ART donated their granulosa cells after oocyte retrieval, 10 were cultivated previously in order to interrupt the luteinization process and then frozen \"Cryostep\" container (group 2C- two cultures) (step 2) and 10 were directly frozen with no previous culture in the \"Cryostep\" container (group DF- direct freeze) (step 3). After thawing these cells were (re)cultured for 144 hours, with medium exchange at 48, 96 and 144 hours to evaluate the estradiol (E2) and progesterone (P4) production (ng/mL). After thawing, there was a reduction in the cell number (p<0,05) and cell viability in both methods, the direct freezing (DF) and the two cultures (2C) (p<0,05); this had an impact in the production of estradiol and progesterone, which were higher in fresh cultures than in the frozen ones (p<0,05). However, the E2/cell ratio was maintained after thawing (p=0.23), suggesting that this impairment in steroid production was probably due to the reduction in the cell count. The cells that survive remain functionally normal. The DF was more efficient since it allowed greater cell recovery and better viability when compared to 2C. The estradiol/progesterone ratio was maintained in all culture times, in the fresh, DF or 2C groups (p>0.05), indicating that the functional characteristic of these cells was preserved post-thawing. We conclude that cryopreservation of human GC obtained during oocyte retrieval compromises the cell count and the overall viability of the culture; however, the functional capacity and the characteristic of these cells are preserved (maintenance of E2/cell and E2/P4 relations)

As técnicas de cultivo de folículos e oócitos in vitro, com o objetivo de se obter oócitos maduros para procedimentos de Reprodução Assistida (RA), têm sido aplicadas em diferentes contextos. O sucesso destes procedimentos está diretamente relacionado ao sistema de cultivo utilizado. A utilização de células da granulosa (CG) humanas cultivadas in vitro como um suporte para o co-cultivo destes oócitos imaturos e folículos tem sido descrita por alguns autores. A criopreservação destas células, considerando-se o contexto de sua obtenção em procedimentos de RA, permitiria a viabilização da aplicação destas células na prática clínica diária. Sendo assim, o objetivo deste estudo foi padronizar o congelamento de células da granulosa (CG) humanas para aplicação em sistemas de co-cultivos de folículos e oócitos imaturos. Foram obtidas CG de 20 voluntárias em tratamento de reprodução assistida, células de 10 voluntárias foram cultivadas em meio ?-MEM suplementado para interrupção da luteinização e congeladas após 48 horas em container \"Cryostep\" (grupo 2C- 2 cultivos) (etapa 2) e células de 10 voluntárias foram congeladas em container \"Cryostep\" sem cultivo prévio (grupo CD- congelamento direto) (etapa 3). Após o descongelamento estas células foram (re)cultivadas por 144 horas, com troca de meio em 48, 96 e 144 horas para avaliações da produção de estradiol (E2) e progesterona (P4) (ng/mL). Verificamos redução na contagem celular e na viabilidade celular tanto no método de congelamento direto (CD) quanto no método com dois cultivos (2C) após o descongelamento (p<0,05), e isso se refletiu na produção de estradiol e progesterona que foi maior nas culturas de células frescas em relação às células criopreservadas (p<0,05). Porém, a relação de E2/célula foi mantida após o descongelamento, sugerindo que esta redução na produção se deve à redução no número de células, as que sobrevivem se mantém normofuncionantes (p=0,23).O CD foi mais eficiente pois permitiu uma maior recuperação celular e uma melhor viabilidade quando comparado ao grupo 2C. A relação estradiol/progesterona foi mantida em todos os tempos de cultivo, fresco, CD e 2C (p>0,05), indicando que a característica funcional destas células foi preservada após o descongelamento. Concluímos que a criopreservação de CG humanas obtidas durante a captação de oócitos compromete a contagem celular e a viabilidade geral da cultura, entretanto, a capacidade funcional e a característica destas células se mantêm preservadas (manutenção das relações E2/célula e E2/P4) / Follicle and oocyte in vitro culture techniques, aiming to obtain mature oocytes for Assisted Reproductive Treatments (ART), have been applied to different contexts. The success of these procedures depends on the culture system used. The use of human granulosa cells (GC) in co-culture systems for follicle and oocyte maturation have been described by some authors. The cryopreservation of these cells, considering the context in which they are obtained during ART, would enable the usage of these cells in such procedures in daily clinical practice. Thus, the objective of this study was to standardize the freezing protocol for human granulosa cells (GC) for future applications in co-culture systems for follicle and oocyte maturation. Twenty volunteers submitted to ART donated their granulosa cells after oocyte retrieval, 10 were cultivated previously in order to interrupt the luteinization process and then frozen \"Cryostep\" container (group 2C- two cultures) (step 2) and 10 were directly frozen with no previous culture in the \"Cryostep\" container (group DF- direct freeze) (step 3). After thawing these cells were (re)cultured for 144 hours, with medium exchange at 48, 96 and 144 hours to evaluate the estradiol (E2) and progesterone (P4) production (ng/mL). After thawing, there was a reduction in the cell number (p<0,05) and cell viability in both methods, the direct freezing (DF) and the two cultures (2C) (p<0,05); this had an impact in the production of estradiol and progesterone, which were higher in fresh cultures than in the frozen ones (p<0,05). However, the E2/cell ratio was maintained after thawing (p=0.23), suggesting that this impairment in steroid production was probably due to the reduction in the cell count. The cells that survive remain functionally normal. The DF was more efficient since it allowed greater cell recovery and better viability when compared to 2C. The estradiol/progesterone ratio was maintained in all culture times, in the fresh, DF or 2C groups (p>0.05), indicating that the functional characteristic of these cells was preserved post-thawing. We conclude that cryopreservation of human GC obtained during oocyte retrieval compromises the cell count and the overall viability of the culture; however, the functional capacity and the characteristic of these cells are preserved (maintenance of E2/cell and E2/P4 relations)

De nos jours, la cryoconservation est une technique très largement utilisée dans les protocoles d’assistance à la reproduction ou comme outil pour la sauvegarde des ressources génétiques. Toutefois, la chienne est un modèle animal complexe pour l’application des biotechnologies de la reproduction du fait de ses nombreuses singularités anatomiques et physiologiques. L’objectif de notre travail était d’étudier et de développer une méthode de cryoconservation des ressources génétiques chez la chienne par le biais de deux types de ressources : les embryons et le tissu ovarien. Après avoir mis au point une méthode de collecte d’embryons, nous nous sommes appliqués à la constitution d’un stock d’embryons cryoconservés en prévision d’un transfert embryonnaire. L’étude et le développement d’un protocole de cryoconservation du tissu ovarien ont été abordés après avoir adapté et validé nos méthodes d’analyses in vitro. L’utilisation de plans d’expériences factoriels fractionnaires a permis de mettre en évidence les facteurs les plus influents sur la qualité de la réserve folliculaire (nature du cryoprotecteur pénétrant, cinétique de congélation, étapes d’équilibration) et de proposer un protocole de cryoconservation. La combinaison du DMSO incorporé en un seul bain d’équilibration avec une vitesse de congélation de 0,3°C/min est apparue comme la combinaison la plus appropriée à la cryoconservation de tissu ovarien chez la chienne et a permis d’observer, après xénogreffe de tissu ovarien cryoconservé, une reprise de la croissance folliculaire et de l’activité hormonale du tissu greffé / Nowadays, cryopreservation is widely used in animal assisted reproduction or safeguarding of genetic resources. Nevertheless, the bitch is a complex animal model concerning the use of this biotechnology, due to numerous anatomical and physiological peculiarities. The aim of our research work was to investigate and develop a method of cryopreservation of genetic resources in the bitch by exploring two kinds of resources: embryos and ovarian tissue. After the setting up of a method for embryo collection, we have built up a stock of cryopreserved embryo for subsequent embryo transfer. After a preliminary validation of our in vitro assessment methods, the investigation and development of a cryopreservation protocol has been conducted. The use of fractional experimental design allowed us to highlight the main factors affecting the follicular pool quality (CPA nature, freezing rate and equilibration steps). The combination of DMSO incorporated in a unique equilibration bath with a freezing rate of 0.3°C/min appeared to be suitable for the cryopreservation of bitch ovarian tissue. Finally, Follicular growth and hormonal activity resumption have been observed after xenotransplantation of cryopreserved bitch ovarian tissue

La conservation de la biodiversité génétique du cochon d’Inde (Cavia porcellus) est importante en tant qu’animal de consommation endémique de la région andine ainsi qu’en tant qu’animal modèle précieux pour la recherche biomédicale.L’objectif de ce travail était de mettre en place les protocoles qui permettront une conservation ex situ des ressources génétiques de cette espèce par la voie femelle. Les étapes nécessaires à la concrétisation d’un projet de cryobanque sont :- la maîtrise de la production d’embryons grâce à des traitements hormonaux de synchronisation du cycle œstral et de superovulation des femelles,- la cryoconservation dans l’azote liquide des embryons obtenus et leur transfert dans des femelles receveuses.Une méthode standardisée de synchronisation des chaleurs basée sur l’administration d’altrenogest per os pendant 15 jours a été définie. Les chaleurs des femelles donneuses et receveuses d’embryons apparaissent dans les 4 à 5 jours qui suivent l’arrêt du traitement de ce progestagène.Des traitements de superovulation basés sur 3 injections à 24 heures d’intervalle d’hMG, ou 6 injections à 12 heures d’intervalle de FSH-recombinante humaine, permettent une augmentation du taux d’ovulation de l’ordre de fois 3 à fois 4 par rapport à des femelles non-traitées. Toutefois les réponses au traitement restent variables et il faudra réitérer l’expérience sur de plus grands lots d’animaux afin d’ajuster les doses et les moments d’application.La méthode de congélation lente, utilisant l’éthylène glycol comme cryoprotecteur, a permis d’obtenir des taux de survie embryonnaire satisfaisants (70,3%). La méthode de vitrification a également donné de bons résultats, avec un taux de survie embryonnaire de 41,7%.Le premier transfert au monde d’embryons frais réalisé avec succès dans une femelle receveuse préalablement synchronisée a été obtenu lors de ce travail. Les transferts d’embryons décongelés n’ont pas encore donné lieu à des gestations. / The preservation of the guinea pig (Cavia porcellus) genetic biodiversity is important as a native source of protein for many highlanders in the Andean region and as a precious laboratory animal for biomedical research.The aim of this work was to establish the protocols that will enable an ex situ preservation of the genetic resources of this species by the female way.The necessary steps for the achievement of a cryobank project are:- the control of the embryo production thanks to hormonal treatments to synchronize the estrous cycles and to superovulate the females,- the cryopreservation in liquid nitrogen of the obtained embryos and their transfer into recipient females.A standard method for synchronization of heat periods based on the per os administration of altrenogest during 15 days has been defined. The heat periods of the females, donors and recipients of embryos, appears 4 to 5 days after the end of the progestagen treatment. Superovulation treatments, based on 3 injections at 24-hour intervals of hMG or 6 injections at 12-hour intervals of human recombinant-FSH, lead to an increase of the ovulation rate of about 3 to 4 times when compared to untreated females. However, the responses to the treatments remain variable and further studies involving a larger number of animals should be carried out in order to adjust the dose and the moment of application of the treatment.The slow-freezing method, using ethylene glycol as cryoprotectant, enables the attainment of a satisfactory in vitro embryo survival rate (70,3%). The vitrification method also gives good results, with a 41,7% in vitro embryo survival rate.The first successful transfer of fresh embryos into a synchronized recipient female has been achieved in this study. The transfers of frozen-thawed embryos did not yet lead to gestation.