Amazing grass: developmental genetics of maize domestication.

Crop plants were domesticated by prehistoric farmers through artificial selection to provide a means of feeding the human population. This article discusses the developmental genetics of crop domestication and improvement, including the historical framework and recent approaches in maize and other grasses. In many cases, selecting for a plant form that correlates with productivity involves controlling meristem activity. In the domestication of modern maize from its progenitor Zea mays ssp. parviglumis, QTL (quantitative trait loci) mapping, genetics and population genomics approaches have identified several genes that contain signatures of selection. Only a few genes involved in the derivation of the highly productive maize ear have been identified, including teosinte glume architecture1 and ramosa1. Future prospects hinge on forward and reverse genetics, as well as on other approaches from the developing discipline of evo-devo (evolutionary developmental biology).

The dermatoglyphics of a Toronto sample of children with XXY, XXYY, and XXX aneuploidies.

Dermatoglyphic analyses were carried out on a sample of children with known sex chromosomal aneuploidies (25 XXY, 10 XXX, 1 XXYY). Digital ridge counts and pattern types were determined for each individual. Palm prints and sole patterns were also examined. The results of our study were compared with data from previous studies of sex chromosomal aneuploidies. Out results for the XXY males agree with the findings from other studies with respect to total ridge counts and plantar dermatoglyphics, but not for digital pattern frequencies. Our one example of an XXYY male showed hypothenar patterns similar to those found for this syndrome by other researchers, but neither the digital pattern types nor the unexpectedly high total ridge count conforms to the findings from other studies. Our sample of XXX females falls within the normal XX female range of variation with respect to hypothenar patterns and total ridge count; plantar features show a higher incidence of patterns than previously reported.