Hb Jeddah [alpha68(E17)Asn-->His (alpha1)]: a newly recognized alpha chain variant, seen in combination with Hb S [beta6(A3)Glu-->Val], and found in three separate families of middle eastern origin.

We report a previously unrecognized alpha chain variant identified in three families from Saudi Arabia, Yemen and Abu Dhabi. The index patient presented for hemoglobinopathy screening and was identified to have both this novel alpha chain variant and Hb S [beta6(A3)Glu-->Val, GAG(-->)GTG]. Hb Jeddah results from a point mutation (AAC(-->)CAC) at codon 68 in exon 2 of the alpha1 gene. There were no apparent hematological abnormalities or clinical symptoms in the three individuals identified as heterozygotes for Hb Jeddah, as well as the index case with both Hb S and Hb Jeddah. As we have found this variant in three separate families, the incidence may be greater than currently recognized.

Mammalian germ-line transgenesis by transposition.

Transposons have been used in invertebrates for transgenesis and insertional mutagens in genetic screens. We tested a functional transposon called Sleeping Beauty in the one-cell mouse embryo. In this report, we describe experiments in which transposon vectors were injected into one-cell mouse embryos with mRNA expressing the SB10 transposase enzyme. Molecular evidence of transposition was obtained by cloning of insertion sites from multiple transgenic mice produced by SB10 mRNA/transposon coinjection. We also demonstrate germ-line transmission and expression from transposed elements. This technique has promise as a germ-line transgenesis method in other vertebrate species and for insertional mutagenesis in the mouse.