We explored distance preferences in the arrangement of binding motifs for five transcription factors (Bicoid, Krüppel, Hunchback, Knirps and Caudal) in a large set of Drosophila cis-regulatory modules (CRMs). Analysis of non-overlapping binding motifs revealed the presence of periodic signals specific to particular combinations of binding motifs. The most striking periodic signals (10 bp for Bi...

The gap gene hunchback (hb) is a key regulator in the anteroposterior patterning of insects. Loss-of-function of hb resulted in segmentation defects in the next generation. In this paper, hb expression level was investigated at different developmental stages of the pea aphid, Acyrthosiphon pisum (Ap). Aphb mRNA was most early detected at the first instar stage and showed an incontinuous increas...

Cellular competence is an essential but poorly understood aspect of development. Is competence a general property that affects multiple signaling pathways (e.g., chromatin state), or is competence specific for each signaling pathway (e.g., availability of cofactors)? Here we find that Drosophila neuroblast 7-1 (NB7-1) has a single early window of competence to respond to four different temporal...

Management of the quality of the Nation’s water requires large quantities of information describing current conditions and related environmental factors. Such information is expensive to collect and difficult to interpret over large scales. To support the efficient use and interpretation of available water-resource information, the U.S. Geological Survey (USGS) developed a spatial water-quality...

A c.:omputational model of song learning in the song sparrow (M elospiza melodia) learns to categorize the different syllables of a song sparrow song and uses this categorization to train itself to reproduce song. The model fills a crucial gap in the computational explanation of birdsong learning by exploring the organization of perception in songbirds. It shows how competitive learning may lea...