Data/hora: 18/05/2024 02:27:32

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 30/10/2002
Data da última atualização: | 30/10/2002
Autoria: | McEVORY, T. G.; COULL, G. D.; BROADBENT, P. J.; HUTCHINSON, J. S. M.; SPEAKE, B. K.
Título: | Fatty acid composition of lipids in immature cattle, pig and sheep oocytes with intact zona pellucida.
Ano de publicação: | 2000
Fonte/Imprenta: | Journal of Reproduction and Fertility, v. 118, n. 1, p. 163-170, 2000.
Idioma: | Inglês
Conteúdo: | Cattle, pig and sheep oocytes isolated from healthy cumulus-oocyte complexes were pooled, within species, to provide samples of immature denuded oocytes with intact zona pellucida (n = 1000 per sample) for determination of fatty acid mass and composition in total lipid, constituent phospholipid and triglyceride. Acyl-containing' lipid extracts, transmethylated in the presence of a reference penta-decaenoic acid (15:0), yielded fatty acid methyl esters which were analysed by gas chromatography. Mean (:t SEM) fatty acid content in samples of pig oocytes (161 +- 18 ug per 1000 oocytes) was greater than that in cattle (63 +- 6 ug; P < 0.01) and sheep oocytes (89 +- t 7 ug; P < 0.05). Of 24 fatty acids detected, palmitic (16:0; 25-35%, w/w), stearic (18:0; 14-16%) and oleic (18:1n-9; 22-26%) acids were most prominent in alI three species. Saturated fatty acids (mean = 45-55%, w/w) were more abundant than mono- (27-34%) or polyunsaturates (11-21%). Fatty acids of the n-6 series, notably linoleic (18:2n-6; 5-8%, w/w) and arachidonic acid (20:4n-6; 1-3%), were the most abundant polyunsaturates. Phospholipid consistently accounted for a quarter of alI fatty acids in the three species, but ruminant oocytes had a lower complement of polyunsaturates (14-19%, w/w) in this fraction than pig oocytes (34%, w/w) which, for example, had a three- to fourfold greater linoleic acid content. An estimated 74 ng of fatty acid was sequestered in the triglyceride fraction of individual pig oocytes compared with 23-25 ng in ruminant ) oocytes (P < 0.01). It is concluded that the greater fatty acid content of pig oocytes is primarily due to more abundant triglyceride reserves. Furthermore, this species- specific difference, and that in respect of polyunsaturated fatty acid reserves, mar underlie the contrasting chilling, culture and cryopreservation sensitivities of embryos derived from pig and ruminant (cattle, sheep) oocytes.
Palavras-Chave: | Lipídios; Oócitos; Ovocito.
Thesagro: | Bovino; Ovino; Reprodução Animal; Suíno.
Categoria do assunto: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
Exemplares: | CNPC - (15051-1) - ADC - AP - -- -  -  - v. 118,n.1 - DIS