Comparison of the localization of several muscle proteins in relaxed and contracted myofibrils.

The localization of several muscle proteins in relaxed and contracted myofibrils is compared. The morphology of the myofibrils and the behavior of these proteins was also investigated under extraction conditions.     

d-andl-isomers of serine and alanine equally effective as releasers of gastrin

Zusammenfassung l-undl-Isomere von Alanin und Serin sind beide wirksam, von der Antrumschleimhaut aus den Gastrinmechanismus zu aktivieren.

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This work was supported by Veterans Administration research funds and by grants from the US Public Health Service.     

Mutant deoxynucleotide carrier is associated with congenital microcephaly

The disorder Amish microcephaly (MCPHA) is characterized by severe congenital microcephaly, elevated levels of alpha-ketoglutarate in the urine and premature death. The disorder is inherited in an autosomal recessive pattern and has been observed only in Old Order Amish families whose ancestors lived in Lancaster County, Pennsylvania. Here we show, by using a genealogy database and automated pedigree software, that 23 nuclear families affected with MCPHA are connected to a single ancestral couple. Through a whole-genome scan, fine mapping and haplotype analysis, we localized the gene affected in MCPHA to a region of 3 cM, or 2 Mb, on chromosome 17q25. We constructed a map of contiguous genomic clones spanning this region. One of the genes in this region, SLC25A19, which encodes a nuclear mitochondrial deoxynucleotide carrier (DNC), contains a substitution that segregates with the disease in affected individuals and alters an amino acid that is highly conserved in similar proteins. Functional analysis shows that the mutant DNC protein lacks the normal transport activity, implying that failed deoxynucleotide transport across the inner mitochondrial membrane causes MCPHA. Our data indicate that mitochondrial deoxynucleotide transport may be essential for prenatal brain growth.