Isolation and characterization of the first microsatellite markers for the southern harvester termite, Microhodotermes viator.

The southern harvester termite, Microhodotermes viator, is ecologically important due to its nutrient cycling activities and trophic interactions. Additionally, M. viator appears to have very long-lived colonies, which amplifies their effect on the environment. In order to estimate the longevity of a colony it is necessary to understand colony genetic structure. However, intra- and intercolonial genetic structure and levels of relatedness have not yet been examined in this species, likely due to a lack of microsatellite markers that effectively hybridize in this species. Here we describe the identification and characterization of seven microsatellite loci for M. viator, using an enriched approach and a preliminary test of their suitability for studies of fine-scale population genetic structure. Seven polymorphic loci were identified, none of which deviated from Hardy-Weinberg equilibrium. The loci had an average of 5.8 alleles per locus (range: 2-14) and an overall mean heterozygosity of 0.51 ± 0.3. Across all loci, population level pairwise F ST values showed significant genetic differentiation. The loci described and preliminary genetic data presented here provide an invaluable tool for future studies of population structure and longevity in M. viator colonies.

Speciation and phylogeography of giant petrels Macronectes.

We examine global phylogeography of the two forms of giant petrel Macronectes spp. Although previously considered to be a single taxon, and despite debate over the status of some populations and the existence of minimal genetic data (one mitochondrial cytochrome b sequence per form), the current consensus based on morphology is that there are two species, Northern Giant Petrel M. halli and Southern Giant Petrel M. giganteus. This study examined genetic variation at cytochrome b as well as six microsatellite loci in giant petrels from 22 islands, representing most island groups at which the two species breed. Both markers support separate species status, although sequence divergence in cytochrome b was only 0.42% (corrected). Divergence was estimated to have occurred approximately 0.2mya, but with some colonies apparently separated for longer (up to 0.5 my). Three clades were found within giant petrels, which separated approximately 0.7mya, with the Southern Giant Petrel paraphyletic to a monophyletic Northern Giant Petrel. There was evidence of past fragmentation during the Pleistocene, with subsequent secondary contact within Southern Giant Petrels. The analysis also suggested a period of past population expansion that corresponded roughly to the timing of speciation and the separation of an ancestral giant petrel population from the fulmar Fulmarus clade.

Molecular insight into patterns of colony composition and paternity in the common mole-rat Cryptomys hottentotus hottentotus.

We report the discovery of intraspecific variation in both colony composition and patterns of paternity in two populations of the social common mole-rat Cryptomys hottentotus hottentotus. These two populations represent the mesic and arid habitat extremes of the species' broad ecological range in South Africa. Until recently colonies of the common mole-rat were thought to consist of familial groups whereby all colony members were the offspring of a monogamous reproductive pair. The remaining colony members were thought to forego reproduction until both social and ecological conditions favoured dispersal and opportunities for independent outbreeding. Results from genetic assignment tests using microsatellite markers indicate that while colony composition is dominated by familial groups, colonies within both populations included both adult and subadult foreign conspecifics. Analysis of parentage reveals that the social organization of C. h. hottentotus is not that of strict monogamy; paternity of offspring was not assigned consistently to the largest, most dominant male within the colony. Moreover, a number of significantly smaller males were found to sire offspring, suggesting a sneak-mating strategy by subordinate within-colony males. Extra-colony extra-pair paternity (ECP) was also found to characterize C. h. hottentotus colonies, occurring with similar frequencies in both habitats. Both dominant established breeding males and subordinate males were identified as siring young in nonsource colonies. Furthermore, established breeding males were found to sire extra-colony young in the same season as siring young within their source colonies. We discuss the significance of these results within the context of the divergent ecological regimes characterizing the two sites and observe that our results revisit the accuracy of using behavioural and morphological characters, which have structured the basis of our understanding of the behavioural ecology of this species, as indicators of breeding status in mark-recapture studies.

Development of a DNA marker by minisatellite associated sequence amplification (MASA) from the endangered Indian rhino (Rhinoceros unicornis).

Rhinoceroses are highly endangered species and their protection warrants immediate remedial measures. Development of DNA markers is envisaged to complement global efforts of the conservation of these extant animals. Minisatellite associated sequence amplification (MASA) of DNA from Indian rhinoceros (Rhinoceros unicornis) and three sub-species of South African black rhinoceros (Diceros bicornis) was carried out using a primer based on consensus sequence of the minisatellite repeat locus 33.15. Several bands in the range of 3.0 kilobases (kb) to 650 base pairs (bp) were identified that were useful for successful differentiation of R. unicornis from D. bicornis. Of these fragments, a 688 bp one, unique to R. unicornis was cloned and sequenced (Accession No. AF-296689). The band patterns uncovered by MASA and the species-specific hybridisation of pSG5 may be utilised as a tool for differentiating the R. unicornis genome from that of D. bicornis. This approach may also be adopted for the development of DNA-based genetic marker(s) useful for identification of other endangered species.

Isolation and characterization of microsatellite loci in black rhinoceros (Diceros bicornis).

The black rhinoceros (Diceros bicornis) is currently one of the most endangered African mammals as a direct result o habitat destruction and intensive poaching. A microsatellite library was constructed to address a number of population genetic questions. This paper describes the isolation of five black rhinoceros microsatellite loci. Three of these loci were found to be polymorphic. In addition, the paper demonstrates the utility for cross-hybridization of these primers in other species of rhinoceros.