In this review, we describe the history of amniote sex determination as a classic example of Darwinian evolution. We suggest that evolutionary changes in sex determination provide a foundation for understanding important aspects of chromosome and genome organization that otherwise appear haphazard in their origins and contents. Species with genotypic sex determination often possess heteromorphi...

Introduction. Recent evidence indicates that clinical examination, for determination of fetal head position, is subjective and inaccurate. Present study was aimed to compare transabdominal ultrasound for fetal head position with vaginal examination during first stage of labor. Material and Methods. This prospective study was performed at a tertiary center during a two-year period. Before or aft...

The sex of a reptile [6] embryo partly results from the production of sex hormones [7] during development, and one such process to produce those hormones [8] depends on temperature of the embryo's environment. The production of sex hormones [7] can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination [9], also ca...

The Y chromosome from certain populations of M. m. domesticus is incapable of normal testis determination in the B6 inbred strain resulting in XY hermaphrodites or XY females (XY(DOM) sex reversal). B6 consomic strains have been developed with either transient (B6-Y(AKR)) or severe (B6-Y(TIR)) XY(DOM) sex reversal. We report that a point mutation, the dominant white spotting oncogene allele, Ki...

The sex of a reptile [6] embryo partly results from the production of sex hormones [7] during development, and one such process to produce those hormones [8] depends on temperature of the embryo's environment. The production of sex hormones [7] can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination [9], also ca...

The sex of a reptile [6] embryo partly results from the production of sex hormones [7] during development, and one such process to produce those hormones [8] depends on temperature of the embryo's environment. The production of sex hormones [7] can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination [9], also ca...

The sex of a reptile [6] embryo partly results from the production of sex hormones [7] during development, and one such process to produce those hormones [8] depends on temperature of the embryo's environment. The production of sex hormones [7] can result solely from genetics or from genetics in combination with the influence of environmental factors. In genotypic sex determination [9], also ca...

The successful identification of human skeletal remains relies on proven diagnostic techniques for sex determination. This research utilized 608 individuals from South Africa (420 men, 188 women) to conduct a blind nonmetric determination of sex from three features of the distal humerus: olecranon fossa shape, angle of the medial epicondyle, and trochlear extension. A scoring system between mal...

Males have a higher morbidity and mortality for neonatal respiratory distress syndrome (RDS) than females, and respond less well to hormone therapy designed to prevent RDS by stimulating fetal pulmonary surfactant production. We have shown that male fetuses exhibit delayed production of pulmonary surfactant. We tested the hypothesis that the sex difference in fetal pulmonary surfactant producti...

BACKGROUND Human males are more vulnerable to adverse conditions than females starting early in gestation and continuing throughout life, and previous studies show that severe food restriction can influence the sex ratios of human births. It remains unclear, however, whether subtle differences in caloric intake during gestation alter survival of fetuses in a sex-specific way. I hypothesized tha...