Effect of adiponectin on bovine granulosa cell steroidogenesis, oocyte maturation and embryo development

<p>Abstract</p> <p>Background</p> <p>Adiponectin is an adipokine, mainly produced by adipose tissue. It regulates several reproductive processes. The protein expression of the adiponectin system (adiponectin, its receptors, AdipoR1 and AdipoR2 and the APPL1 adaptor) in bovine ovary and its role on ovarian cells and embryo, remain however to be determined.</p> <p>Methods</p> <p>Here, we identified the adiponectin system in bovine ovarian cells and embryo using RT-PCR, immunoblotting and immunohistochemistry. Furthermore, we investigated in vitro the effects of recombinant human adiponectin (10 micro g/mL) on proliferation of granulosa cells (GC) measured by [3H] thymidine incorporation, progesterone and estradiol secretions measured by radioimmunoassay in the culture medium of GC, nuclear oocyte maturation and early embryo development.</p> <p>Results</p> <p>We show that the mRNAs and proteins for the adiponectin system are present in bovine ovary (small and large follicles and corpus luteum) and embryo. Adiponectin, AdipoR1 and AdipoR2 were more precisely localized in oocyte, GC and theca cells. Adiponectin increased IGF-1 10(-8) M-induced GC proliferation (P < 0.01) but not basal or insulin 10(-8) M-induced proliferation. Additionally, adiponectin decreased insulin 10(-8) M-induced, but not basal or IGF-1 10(-8) M-induced secretions of progesterone (P < 0.01) and estradiol (P < 0.05) by GC. This decrease in insulin-induced steroidogenesis was associated with a decrease in ERK1/2 MAPK phosphorylation in GC pre-treated with adiponectin. Finally, addition of adiponectin during in vitro maturation affected neither the percentage of oocyte in metaphase-II nor 48-h cleavage and blastocyst day 8 rates.</p> <p>Conclusions</p> <p>In bovine species, adiponectin decreased insulin-induced steroidogenesis and increased IGF-1-induced proliferation of cultured GC through a potential involvement of ERK1/2 MAPK pathway, whereas it did not modify oocyte maturation and embryo development in vitro.</p

Ultrabrza vitrifikacija u otvorenoj rastegnutoj slamci otvara nove mogućnosti za smrzavanje konjskih zametaka.

The aim of this research was to evaluate ultra rapid OPS vitrification on the embryo viability. The OPS vitrification technique is comprised of ultra rapid freezing of a small drop in which the embryo is placed. Before the thin straw was plunged into the liquid nitrogen, the embryos were treated with highly concentrated cryoprotectant (CPA) solutions as follows: 18% ethylene glycol (EG), 18% dimethyl-sulfoxide (DMSO) and 0.4 M sucrose. Surgical transfer into the recipient mares and morphologic examination of recollected embryos were used to measure the viability of transferred embryos. The research was performed on Welsh pony mares by collecting the embryos 6.75 days after ovulation. Twenty embryos were vitrified and transferred, four in each recipient mare. At day twelve, nine embryos were recollected after fl ushing of the recipient uterus (56%, 9/ 16). In one recipient mare, endometritis was detected when the uterus was fl ushed. Among the sixteen recollected embryos, seven (44%) had normal morphology and well developed embryonic vesicles. The vitrification procedure used proved to be encouraging.Svrha istraživanju bila je ustanoviti učinkovitost ultrabrze vitrifikacije u otvorenoj rastegnutoj slamci na vitalnost konjskih zametaka, prijenosom vitrificiranih pa otopljenih zametaka u sinkronizirane primateljice. Istraživanje je provedeno na stadu Welsh poni kobila. Davateljicama zametaka maternice su transcervikalno bile ispirane 6,75 dana nakon ovulacije, a zametci su nakon vitrifikacije bili pohranjeni u spremnik s tekućim dušikom. Nakon odmrzavanja, zametci su bili prenijeti u sinkronizirane primateljice. Maternice primateljica bile su ispirane petoga dana nakon prijenosa odmrznutih zametaka. Ukupno je bilo preneseno dvadeset zametaka, a ispiranjem maternica primateljica dobiveno je devet zametaka što iznosi 56% s obzirom da je u jedne primateljice ispiranjem ustanovljen endometritis. Od zametaka dobivenih ispiranjem primateljica, sedam (44%) je imalo morfološki normalno razvijene zametne mjehure. Na osnovi provedenih istraživanja zaključeno je da su rezultati ostvareni vitrifikacijom u otvorenoj rastegnutoj slamci ohrabrujući, ali bi ih s obzirom na mali broj prenijetih zametaka trebalo potvrditi na većem uzorku, posebice sa zametcima odabranoga promjera te brojem ždrebadi

Acidification post mortem dans le muscle de veau. Consequences sur la structure et sur les qualites organoleptiques de la viande

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 82894 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Micromanipulation des gamètes

National audienceCet article fait partie du dossier : Actualités en reproduction équin

Cryoconservation des embryons des espèces domestiques

National audienceCryopreservation of mammalian embryos was developed during the late 1970s. Since then, the cryopreservation techniques have been diversified and improved to try to cryopreserve embryos from most species, at different developmental stages, and more sensitive embryos such as in vitro produced, cloned or biopsied embryos. Slow freezing (or equilibrium freezing) and vitrification are the main cryopreservation techniques commonly used. Slow freezing attempts to maintain a delicate balance between cryoprotectants and the aqueous embryo compartment, whereas the strategy of the vitrification method is a rapid solidification of liquid without ice crystal formation. The OPS technique (Open Pulled Straw) is a faster vitrification process. All techniques offer advantages and disadvantages, but slow freezing is currently the most used on farm applications in sheep, goats and cattle with embryos produced in vivo. In pigs, only the OPS technique allows to cryopreserve embryos with good success. In the equine, none of these different techniques gives good results : only a few foals have been born after transfer of cryopreserved embryos.Le début de la cryoconservation d’embryons de mammifères remonte aux années 70. Depuis, les techniques se sont multipliées et diversifiées pour essayer de répondre aux problèmes que posaient certaines espèces, certains stades de développement embryonnaire et les embryons fragilisés comme les embryons produits in vitro, issus de clonage ou encore les embryons biopsiés. Sont principalement utilisées, la congélation lente qui est basée sur l’équilibration progressive entre les cryoprotecteurs et le compartiment aqueux de l’embryon, la vitrification qui transforme rapidement la phase liquide du cytoplasme embryonnaire en phase solide amorphe appelée « état vitreux », et l’OPS (Open Pulled Straw) qui est une vitrification très rapide. Chaque technique a ses avantages et ses inconvénients, mais la congélation lente est actuellement la technique de référence sur le terrain en ovin, caprin et bovin avec des embryons produits in vivo. Par contre, pour les porcins, seule la technique d’OPS permet une bonne cryconservation des embryons. Dans l’espèce équine, aucune technique ne donne de très bons résultats : les poulains nés après transfert d’embryons cryoconservés sont encore rares

Le point sur la cryopréservation des embryons

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Genotyping and cryopreservation of equine embryos: new developments

National audienc

Determination sex and scrapie resistance genotype of preimplantation caprine embryos

International audienc

Naissance de 4 poulains issus de transferts d'embryons génotypés et cryoconservés : une première européenne

National audienceQuatre poulains issus d’une collaboration de recherche entre l’Inra de Nouzilly et la Jumenterie du Pin sont nés ce printemps. L’originalité de ces poulains réside dans le fait que les embryons ont été au préalable génotypés et cryoconservés. Les objectifs de ces travaux de recherche sont multiples pour la filière équine