RESUMO
The present study determined the transcriptome profile in Nelore and Holstein oocytes subjected to heat shock during IVM and the mRNA abundance of selected candidate genes in Nelore and Holstein heat-shocked oocytes and cumulus cells (CC). Holstein and Nelore cows were subjected to in vivo follicle aspiration. Cumulus-oocyte complexes were assigned to control (38.5°C, 22h) or heat shock (41°C for 12h, followed by 38.5°C for 10h) treatment during IVM. Denuded oocytes were subjected to bovine microarray analysis. Transcriptome analysis demonstrated 127, nine and six genes were differentially expressed between breed, temperature and the breed×temperature interaction respectively. Selected differentially expressed genes were evaluated by real-time polymerase chain reaction in oocytes and respective CC. The molecular motor kinesin family member 3A (KIF3A) was upregulated in Holstein oocytes, whereas the pro-apoptotic gene death-associated protein (DAP) and the membrane trafficking gene DENN/MADD domain containing 3 (DENND3) were downregulated in Holstein oocytes. Nelore CC showed increased transcript abundance for tight junction claudin 11 (CLDN11), whereas Holstein CC showed increased transcript abundance for antioxidant metallothionein 1E (MT1E) . Moreover, heat shock downregulated antioxidant MT1E mRNA expression in CC. In conclusion, oocyte transcriptome analysis indicated a strong difference between breeds involving organisation and cell death. In CC, both breed and temperature affected mRNA abundance, involving cellular organisation and oxidative stress.
Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Células do Cúmulo/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Resposta ao Choque Térmico/genética , Cinesinas/metabolismo , Oócitos/metabolismo , Transcriptoma , Animais , Proteínas Reguladoras de Apoptose/genética , Bovinos , Regulação para Baixo , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina/genética , Temperatura Alta , Cinesinas/genética , Regulação para CimaRESUMO
This review highlights the importance of energy and protein nutrition of the dam on embryo production and embryo development. Fertility is reduced by greater negative energy balance post-partum as manifest by reductions in fertility and embryo quality associated with lower body condition score (BCS) but particularly with greater postpartum loss of BCS. In addition, excessive energy intake, particularly from high carbohydrate diets can reduce fertilization and embryo quality in some but not all circumstances. High protein diet s have been found to reduce embryo quality by day 7 after breeding, possibly due to greater blood urea nitrogen, however this negative effect is not observed in all studies. Sufficient circulating concentrations of amino acids, particularly rate-limiting amino acids such as methionine and lysine are critical for optimal milk production. The rate-limiting amino acids may also impact embryonic development, perhaps through improved amino acid profiles in the uterine lumen. Methionine may also have direct epigenetic effects in the embryo by methylation of DNA. Future studies are needed to replicate previously observed positive and negative effects of energy, excess protein, and amino acid supplementation in order to provide further insight into how embryonic development can be rationally manipulated using nutritional strategies.(AU)
Assuntos
Animais , Feminino , Bovinos/crescimento & desenvolvimento , Desenvolvimento Embrionário , Aminoácidos/administração & dosagem , Metionina/administração & dosagem , Proteínas/administração & dosagem , Fenômenos Fisiológicos da Nutrição Animal , Fenômenos Fisiológicos da Nutrição Pré-NatalRESUMO
This review highlights the importance of energy and protein nutrition of the dam on embryo production and embryo development. Fertility is reduced by greater negative energy balance post-partum as manifest by reductions in fertility and embryo quality associated with lower body condition score (BCS) but particularly with greater postpartum loss of BCS. In addition, excessive energy intake, particularly from high carbohydrate diets can reduce fertilization and embryo quality in some but not all circumstances. High protein diet s have been found to reduce embryo quality by day 7 after breeding, possibly due to greater blood urea nitrogen, however this negative effect is not observed in all studies. Sufficient circulating concentrations of amino acids, particularly rate-limiting amino acids such as methionine and lysine are critical for optimal milk production. The rate-limiting amino acids may also impact embryonic development, perhaps through improved amino acid profiles in the uterine lumen. Methionine may also have direct epigenetic effects in the embryo by methylation of DNA. Future studies are needed to replicate previously observed positive and negative effects of energy, excess protein, and amino acid supplementation in order to provide further insight into how embryonic development can be rationally manipulated using nutritional strategies.
Assuntos
Feminino , Animais , Aminoácidos/administração & dosagem , Bovinos/crescimento & desenvolvimento , Desenvolvimento Embrionário , Metionina/administração & dosagem , Proteínas/administração & dosagem , Fenômenos Fisiológicos da Nutrição Animal , Fenômenos Fisiológicos da Nutrição Pré-NatalRESUMO
Diets can alter the concentrations of circulating hormones such as insulin and IGF_I. Such responsive hormones are related directly to nutritional status and moreover, directly or indirectly associated with reproductive function and fertility. Metabolic hormones are involved in follicular development, number and size of ovarian structure, circulating concetrations of steroid hormones duration of estrus, steroidogenesis, ovulation and embryonic development. Howeverm circulating metabolic hormones in excess, resulting from high dry matter/energy intake can also contribute to the reduction of oocytes and embryo quality. Although changes in dietary intake affect ovarian funciton in Bos taurus and Bos indicus cattle, it seems that overfeeding influences more profoundly oocytes/embryos from heifers and cows of Bos taurus than of Bos indicus breeds. There is also a distinct effect of nutrition on in vitro vs. in vivo embryo production, in which metabolic hormones seem to affect more the la ter stages of follicle development. Thus, this paper presents and discusses the results of some relevant studies on the role of feed intake and its association with metabolic hormones in mbovinemreproduction.(AU)
Assuntos
Animais , Insulina/química , Hormônios/biossíntese , Fertilidade/fisiologia , Esteroides , Bovinos/fisiologia , Embrião de Mamíferos/embriologiaRESUMO
Diets can alter the concentrations of circulating hormones such as insulin and IGF_I. Such responsive hormones are related directly to nutritional status and moreover, directly or indirectly associated with reproductive function and fertility. Metabolic hormones are involved in follicular development, number and size of ovarian structure, circulating concetrations of steroid hormones duration of estrus, steroidogenesis, ovulation and embryonic development. Howeverm circulating metabolic hormones in excess, resulting from high dry matter/energy intake can also contribute to the reduction of oocytes and embryo quality. Although changes in dietary intake affect ovarian funciton in Bos taurus and Bos indicus cattle, it seems that overfeeding influences more profoundly oocytes/embryos from heifers and cows of Bos taurus than of Bos indicus breeds. There is also a distinct effect of nutrition on in vitro vs. in vivo embryo production, in which metabolic hormones seem to affect more the la ter stages of follicle development. Thus, this paper presents and discusses the results of some relevant studies on the role of feed intake and its association with metabolic hormones in mbovinemreproduction.
Assuntos
Animais , Esteroides , Fertilidade/fisiologia , Hormônios/biossíntese , Insulina/química , Bovinos/fisiologia , Embrião de Mamíferos/embriologiaRESUMO
Circulating concentration of progesterone (P4) is determined by a balance between P4 production, primarily by corpus luteum (CL), and P4 metabolism, primarily by liver. The volume of large luteal cells in the CL is a primary factor regulating P4 production. Rate of P4 metabolism is generally determined by liver blood flow and can be of critical importance in determining circulating P4 concentrations, particularly in dairy cattle. During timed AI protocols, elevations in P4 are achieved by increasing number of CL by ovulation of accessory CL or by supplementation with exogenous P4. Dietary manipulations, such as fat supplementation, can also be used to alter circulating P4. Elevating P4 prior to the timed AI generally decreases double ovulation an d can increase fertility to the timed AI. This appears to be an effect of P4 during the follicular wave that produces the future ovulatory follicle, possibly by altering the oocyte and subsequent embryo. Near the time of AI, slight elevations in circulating P4 can dramatically reduce fertility. The etiology of slight elevations in P4 near AI is inadequate luteolysis to the prostaglandin F2 α (PGF) treatment prior to timed AI. After AI, circulating P4 is critical for embryo growth and establishment and maintenance of pregnancy. Many studies have attempted to improve fertility by elevating P4 after timed AI. Combining results of these studies indicated only marginal fertility benefits of <5%. In conclusion, previous research has provided substantial insight into the effects of supplemental P4 on fertility and there is increasing insight into the mechanisms regulating circulating P4 concentrations and actions. Understanding this prior research can focus future re search on P4 manipulation to improve timed AI protocols.(AU)
Assuntos
Animais , Prenhez/fisiologia , Corpo Lúteo/anatomia & histologia , Folículo Ovariano/anatomia & histologia , Ruminantes/classificação , Primatas/classificaçãoRESUMO
Circulating concentration of progesterone (P4) is determined by a balance between P4 production, primarily by corpus luteum (CL), and P4 metabolism, primarily by liver. The volume of large luteal cells in the CL is a primary factor regulating P4 production. Rate of P4 metabolism is generally determined by liver blood flow and can be of critical importance in determining circulating P4 concentrations, particularly in dairy cattle. During timed AI protocols, elevations in P4 are achieved by increasing number of CL by ovulation of accessory CL or by supplementation with exogenous P4. Dietary manipulations, such as fat supplementation, can also be used to alter circulating P4. Elevating P4 prior to the timed AI generally decreases double ovulation an d can increase fertility to the timed AI. This appears to be an effect of P4 during the follicular wave that produces the future ovulatory follicle, possibly by altering the oocyte and subsequent embryo. Near the time of AI, slight elevations in circulating P4 can dramatically reduce fertility. The etiology of slight elevations in P4 near AI is inadequate luteolysis to the prostaglandin F2 α (PGF) treatment prior to timed AI. After AI, circulating P4 is critical for embryo growth and establishment and maintenance of pregnancy. Many studies have attempted to improve fertility by elevating P4 after timed AI. Combining results of these studies indicated only marginal fertility benefits of <5%. In conclusion, previous research has provided substantial insight into the effects of supplemental P4 on fertility and there is increasing insight into the mechanisms regulating circulating P4 concentrations and actions. Understanding this prior research can focus future re search on P4 manipulation to improve timed AI protocols.