Cross‐hybridization of the grey seal myoglobin gene to human DNA detected a single human myoglobin gene plus an extensive family of sequences apparently related to the central exon of this gene. The functional human gene is 10.4 kb long and has a haemoglobin‐like three exon/two intron structure with long non‐coding regions similar to its seal homologue. At least 300 bp of 5′‐flanking region are closely homologous between the two genes, with the exception of a divergent purine‐rich region 68‐114 bp upstream of the cap site. A diverged tandem repetitive sequence based on (GGAT)165 is located 1100‐1750 bp upstream from the gene; internal homology units within this sequence suggest sequence homogenization by gene microconversions. A second 33‐bp tandem repeat element in the first intron is flanked by a 9‐bp direct repeat, shares homology with other tandem repetitive elements in the human genome and may represent a novel form of transposable element.

The tetrameric haemoglobins of vertebrates are encoded by alpha- and beta-globin gene families which arose during evolution by a succession of gene duplications, commencing with an alpha beta globin gene duplication which occurred about 500 Myr ago, early in the evolution of the vertebrates. All functional alpha- and beta- globin genes analysed so far share common features, including coding sequence homologies and the presence of two introns within the coding sequence at locations which correlate with interdomain boundaries within globin polypeptides. Here we describe the isolation and characterization of an additional diverged member of the globin gene family, the seal myoglobin gene. We show that monomeric myoglobin, which diverged from haemoglobin about 600-800 Myr ago before the appearance of tetrameric haemoglobins, is also specified by a gene containing two introns at positions precisely homologous to haemoglobin introns. Unlike vertebrate haemoglobin genes, however, the noncoding regions of the seal myoglobin gene are remarkably long.

A recombinant plasmid, pHMd.24, was constructed which contains an array of a 24 bp sequence from the genome of the Musca domestica. This sequence hybridizes to sites occurring at various genomic locations in different housefly strains. The pHMd.24 insert has a structural organisation similar to satellite DNA sequences and hybridizes to homologous repeated sequences representing a small fraction of the M. domestica genome. Interestingly, this clone reveals polymorphic fragments from DNA isolated from single houseflies, thus generating an insect DNA fingerprint. In addition, the segregation of the fragments detected by hybridisation in a M. domestica pedigree indicates a transmission that follows mendelian inheritance.

The most conventional approach for evaluating genetic variability in an insect population involves assessing the degree of enzyme polymorphism. Hymenoptera display a relatively low level of genetic variability compared with most insect species. DNA probes consisting of tandemly repeated sequences are powerful tools for detecting polymorphisms when employed to develop DNA fingerprinting (DNAfp) profiles in a wide range of organisms. This report describes genetic variability in the solitary bee species Megachile rotundata as assessed by DNAfp using the M13 sequence and a synthetic oligonucleotide sequence homologous to a hypervariable region of the alpha-globin gene. DNAfp comparisons among offspring were used to analyze genealogical structure in M. rotundata nests. The results indicate that polyandry, by a large number of males, is not a common phenomenon in M. rotundata bee species. In the present analysis, it is likely that the broods raised in single nests are mostly the offspring of one singly mated female. However, the data does not preclude that for certain nests two males could have been involved in the mating process.

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