[Mutation by deletion-insertion in BRCA-1 gene in three unrelated French breast/ovarian cancer families: possible implication of a mobile element].

A new type of mutation by deletion-insertion in BRCA-1 gene is found in three unrelated French breast/ovarian cancer families. Surprisingly, deletion and insertion occurred at the same nucleotide position at the end of exon 11 (3958del5ins4), thus generating a truncated protein. This original mutation consists in a deletion of 5 bp (CTCAG) and in an insertion of 4 different bp (AGGC).

Systematic sequencing of the BRCA-1 coding region for germ-line mutation detection in 70 French high-risk families.

Seventy French high-risk families were screened for germ-line BRCA-1 mutations. The BRCA-1 coding region and the exon-intron boundaries were sequenced, except when pre-screening by PTT revealed a truncated protein in exon 11. Germ-line BRCA-1 mutations were detected in 24% of families.

New mechanism of BRCA-1 mutation by deletion/insertion at the same nucleotide position in three unrelated French breast/ovarian cancer families.

A novel complex mutation consisting of a small deletion/insertion (3958del5ins4) was found in the breast cancer-1 gene (BRCA-1) in three unrelated French breast and/or ovarian cancer families. These mutations occurred at the same nucleotide position of the 3' end of exon 11. The wild-type sequence, CTCAG, was deleted and replaced by AGGC in the three families.

Expression of lactate dehydrogenase, myosin heavy chain and myogenic regulatory factor genes in rabbit embryonic muscle cell cultures.

The expression of myogenic regulatory factors (MRFs), lactate dehydrogenase (LDH) and myosin heavy chains (MyHC), as markers of myogenesis, metabolism and contractility respectively, were investigated during differentiation of rabbit embryonic muscle cells in primary culture. Myf5, MyoD and myogenin mRNAs were abundantly expressed at day 1 of culture. The expression of Myf5 and MyoD mRNA transcripts decreased sharply as myoblasts fused and differentiated into myotubes, whilst myogenin mRNA was maintained throughout the duration of the culture.