The words of the regulatory code are arranged in a variable manner in highly conserved enhancers.

The cis-regulatory regions of many developmental regulators and transcription factors are believed to be highly conserved in the genomes of vertebrate species, suggesting specific regulatory mechanisms for these gene classes. We functionally characterized five notochord enhancers, whose sequence is highly conserved, and systematically mutated two of them. Two subregions were identified to be essential for expression in the notochord of the zebrafish embryo.

Birth after pre-implantation genetic diagnosis (PGD) of spinocerebellar ataxia 2 (Sca2).

Background: Spinocerebellar ataxia 2 (SCA2) is an autosomal-dominant neurodegenerative disease caused by an extended polyglutamine sequence in the ATXN2 protein. We describe the development of a new single-cell multiplex PCR protocol for pre-implantation genetic diagnosis (PGD) of SCA2 and its successful clinical application.

Methods: Three duplex tests have been developed, one, which combines the detection of the CAG repeats in addition to the D12S821 microsatellite, another, the amplification of the CAG repeats and the D12S1333 microsatellite and the last, the combination of both microsatellites D12S821 and D12S1333.

Conserved and acquired features of neurogenin1 regulation.

The telencephalon shows vast morphological variations among different vertebrate groups. The transcription factor neurogenin1 (ngn1) controls neurogenesis in the mouse pallium and is also expressed in the dorsal telencephalon of the evolutionary distant zebrafish. The upstream regions of the zebrafish and mammalian ngn1 loci harbour several stretches of conserved sequences.