Sex determination proceeds through various mechanisms, which can be broadly grouped into two categories. In genetic sex determination (GSD), differentiation results from intrinsic genetic differences between males and females, whereas in environmental sex determination (ESD), differentiation results from environmental signals such as temperature, light and population density. Compared with GSD, the genetics underlying ESD areContinueContinue reading “Sex determination mechanisms linked”
Tag Archives: development
New chromosome, new species
The formation of new species is typically driven by environmental adaptation. But a recent investigation of neighboring populations of threespine stickleback fish (Gasterosteus aculeatus) has now shown, for the first time, that creation of a new sex chromosome can contribute to speciation. Lab Anim. (NY) 38, 341 (2009). view full text (login required)
Estrogen helps make mice male
Sexual dimorphism is the presence of different behaviors and characteristics in males versus females. Its development relies on an intricate interplay of genetic, chromosomal and hormonal factors, particularly during certain stages of development. In mammals, sexual dimorphism is thought to result from exposure to sex hormones during the perinatal stage of development. In male rats,ContinueContinue reading “Estrogen helps make mice male”
Showing teeth where to grow
Tooth growth in mammals is restricted to a single row, whereas non-mammalian vertebrates, such as sharks, grow multiple rows of teeth. Until recently, the mechanisms that enabled or restricted iterative tooth development were not well understood. Understanding these regulatory mechanisms may hold benefits for humans—we don’t need multiple rows of teeth, but being able toContinueContinue reading “Showing teeth where to grow”
Sugars click with zebrafish
New advances in molecular tagging may one day offer deeper insights into the development of diseases such as cancer and heart disease. Now in its infancy, the technique has been applied to tracking the development of the zebrafish embryo in vivo using noninvasive imaging of sugar molecules. Lab Anim. (NY) 37, 236 (2008). view full text (loginContinueContinue reading “Sugars click with zebrafish”
Preventing a craniofacial disorder
Treacher Collins syndrome (TCS) is a craniofacial development disorder that affects roughly 1 in 50,000 people. It is characterized by underdeveloped facial bones, which frequently results in a sunken appearance in the middle of the face, a prominent nose, a very small jaw and chin and downward-slanting eyes; some affected individuals also have cleft palateContinueContinue reading “Preventing a craniofacial disorder”
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