RESUMEN
The aim of this paper is to demonstrate that there are significant ethical problems with nonmedical sex selection, and that prohibitive legislation is justified. The central argument put forward is that nonmedical sex selection is a sexist practice which promotes socially restrictive conceptions of sex, gender and family. Several steps are taken to justify this position: background information on technology and legislation is provided, the neoliberal position that is supportive of nonmedical sex selection is described, and preliminary reasons for rejecting this approach are given. A detailed description of how a harm/benefit based analysis contributes to the argument against nonmedical sex selection, and how it successfully counters most criticism, is provided. The paper concludes by suggesting that virtue ethics further strengthens the moral argument against nonmedical sex selection.
Asunto(s)
Discusiones Bioéticas , Técnicas Reproductivas Asistidas/ética , Preselección del Sexo/ética , Femenino , Humanos , MasculinoRESUMEN
The transcription factor Pit-1/GHF-1 plays an important role in regulating the prolactin (Prl) and growth hormone (GH) genes in mammals. In this study, the role that Pit-1 plays in regulating the prolactin and growth hormone genes in avian species was examined by cotransfection assays and immunofluorescence staining of pituitary sections. In cotransfection assays, turkey Pit-1 activated the turkey Prl, turkey GH, and rat Prl promoters 3.8-, 3.7-, and 12.5-fold, respectively. This activation was comparable to rat Pit-1 activation of these same promoters. A point mutation in the turkey Pit-1 cDNA, which changed leu-219 to ser-219, resulted in a 2-, 2-, and 10-fold reduction in the activation of the turkey Prl, turkey GH, and rat Prl promoters, respectively. Unexpectedly, coexpression of tPit-1 (leu-219) and tPit-1(ser-219) activated turkey Prl and rat Prl promoters 9.4- and 35.9-fold, respectively, but had no effect on the turkey GH promoter. Dual-label immunofluorescence analysis of turkey pituitary sections revealed that Pit-1 was not detectable in prolactin-staining cells but was detectable in GH-staining cells. Taken together, these data indicate that in the domestic turkey, Pit-1 can activate the turkey Prl promoter in vitro, but does not appear to play a role in regulating Prl gene expression in vivo. Pit-1, however, still likely plays a role in regulating GH gene expression.
Asunto(s)
Proteínas de Unión al ADN/farmacología , Hormona del Crecimiento/genética , Hipófisis/química , Prolactina/genética , Regiones Promotoras Genéticas , Factores de Transcripción/farmacología , Pavos/genética , Región de Flanqueo 5' , Animales , Secuencia de Bases , Línea Celular , Núcleo Celular/química , Clonación Molecular , Proteínas de Unión al ADN/análisis , Proteínas de Unión al ADN/genética , Técnica del Anticuerpo Fluorescente , Regulación de la Expresión Génica/efectos de los fármacos , Vectores Genéticos , Hormona del Crecimiento/análisis , Células HeLa , Humanos , Ratones , Datos de Secuencia Molecular , Hipófisis/metabolismo , Hipófisis/ultraestructura , Prolactina/análisis , Ratas , Factor de Transcripción Pit-1 , Factores de Transcripción/análisis , Factores de Transcripción/genética , TransfecciónRESUMEN
Pregnant mares serum gonadotrophin (PMSG) was used in combination with prostaglandin F2alpha or its analogues to induce superovulation in 25 heifers. Total unconjugated oestrogen and progesterone were determined in peripheral plasma of these superovulated animals, and the levels compared with those found during the normal oestrous cycle. A very high level of oestrogen was found between day 3 and 6 after superovulation, and it seems likely that large unovulated follicles were responsible for the excess steroid. Similarly, progesterone levels were raised in the superovulated animal presumably due to production by the numerous corpora lutea. In two heifers, in which overstimulation of follicular development had occurred, there were no ovulations in one of the animals while in the other animal there were 16 ovulations but early regression of corpora lutea was indicated. It is concluded that the poor recovery of eggs on day 6 after superovulation could have been due to deleterious effects of high levels of oestrogen on either the motility of the genital tract causing the premature transport of eggs, or the properties of the zona pellucida.