C. elegans occurs in two natural sexes, the XX hermaphrodite and the XO male, which differ extensively in anatomy, physiology, and behavior. All somatic differences between the sexes result from the differential activity of a "global" sex determination regulatory pathway. This pathway also controls X chromosome dosage compensation, which is coordinated with sex determination by the action of th...

N Engl J Med 2004;350:367-78. Copyright © 2004 Massachusetts Medical Society. ex determination, which depends on the sex-chromosome complement of the embryo, is established by multiple molecular events that direct the development of germ cells, their migration to the urogenital ridge, and the formation of either a testis, in the presence of the Y chromosome (46,XY), or an ovary in the absence o...

Reptiles posses two main mechanisms of sex determination. In some species the sex of the individual is determined at conception by sex factors contained in sex chromosomes (termed genotypic sex determination or GSD). However, in other species sex is determined after conception by the environmental temperature during incubation and cannot be predicted by zygotic genotype (Bull, 1983; Valenzuela ...

Temperature-dependent sex determination (TSD) in the red-eared slider turtle, Trachemys scripta, has been the subject of a variety of past studies. Incubation temperature appears to affect sex determination in a dose-dependent fashion. This suggests that temperature could be affecting a dosage-sensitive element in the sex-determination cascade. Sex determination in T. scripta is sensitive to es...

Despite the identification of SRY as the testis-determining gene in mammals, the genetic interactions controlling the earliest steps of male sex determination remain poorly understood. In particular, the molecular lesions underlying a high proportion of human XY gonadal dysgenesis, XX maleness and XX true hermaphroditism remain undiscovered. A number of screens have identified candidate genes w...

What is sex determination? Sex determination is the mechanism by which sexual organisms direct gonad development towards distinct but reproductively compatible outcomes. Molecular signaling cascades in the developing gonad provide instructions to the tissue to develop as male or female (or in some cases hermaphrodite), and these signals can be initiated in different ways. Sex can be determined ...

Sex determination is as important for the fitness of plants as it is for animals, but its mechanisms appear to vary much more among plants than among animals, and the expression of gender in plants differs in important respects from that in most animals. In this Minireview, I provide an overview of the broad variety of ways in which plants determine sex. I suggest that several important peculia...

Sex determination is a hierarchically-regulated process with high diversity in different organisms including insects. The W chromosome-derived Fem piRNA has been identified as the primary sex determination factor in the lepidopteran insect, Bombyx mori, revealing a distinctive piRNA-mediated sex determination pathway. However, the comprehensive mechanism of silkworm sex determination is still p...

Giardia lamblia is one of the pathogenic parasites that infect gastrointestinal tract and commonly causes diarrhoea, iron deficiency anemia, other problem in men, especially among children poor sanitation areas with contaminated drinking water resources. This study aimed to detect determination rate giardiasis Duhok city. In this study, 105 Stool samples were collected from different ages both ...