Isozyme and allozyme markers distinguishing two morphologically similar, medically important Mastomys species (Rodentia: Muridae)

BACKGROUND: Two common southern African mice species, Mastomys coucha and M. natalensis, are widely distributed throughout the subregion and overlap in many areas. They also share a high degree of morphological similarity, making them impossible to distinguish in the field at present. These multimammate mice are documented carriers of serious disease vectors causing Lassa fever, plague and encephalomyocarditis, which coupled to their cohabitation with humans in many areas, could pose a significant health risk. A preliminary study reported the presence of isozyme markers at three loci (GPI-2, PT-2, -3) in one population each of M. coucha and M. natalensis. Two additional populations (from the Vaal Dam and Richards Bay) were sampled to determine the reliability of these markers, and to seek additional genetic markers. RESULTS: Fifteen proteins or enzymes provided interpretable results at a total of 39 loci. Additional fixed allele differences between the species were detected at AAT-1, ADH, EST-1, PGD-1, Hb-1 and -2. Average heterozygosities for M. coucha and M. natalensis were calculated as 0.018 and 0.032 respectively, with a mean genetic distance between the species of 0.26. CONCLUSIONS: The confirmation of the isozyme and the detection of the additional allozyme markers are important contributions to the identification of these two medical and agricultural pest species

Microsatellite markers reveal low genetic differentiation among southern African Camelus dromedarius populations

We report new demographic and genetic data on southern African camel (Camelus dromedarius) populations. Results from questionnaires on demography indicated that approximately 476 camels were extant in South Africa, Namibia and Botswana in 2003. We have sampled 234 camels for genetic analysis using a microsatellite marker set consisting of 12 loci. Results indicated little differentiation between camels from southern Africa, the Sudan or an outgroup from the family Camelidae, the alpaca (Lama pacos). Analysis of molecular variance (AMOVA) showed that -0.09% of total variation reside between species, 0.26% between the two southern African camel populations and 99.83% within populations. A coefficient of population differentiation (RST) indicated low levels of differentiation between southern African camel populations, with no specific pattern observed in pair-wise comparisons of 16 populations. An assignment test conformed to known population histories and provided additional support for the hypothesis of low differentiation between populations. There was no evidence of loss of genetic diversity in any individual population. Parentage analysis confirmed the utility of the microsatellite marker set for elucidating uncertain paternity. The results are discussed with reference to the management history of camels in the southern African region and the importance of population and parentage verification in the light of the many historic translocations. Keywords: Camel; genetic differentiation; Camelus dromedaries; genetic variation; microsatellites South African Journal of Animal Sciences Vol. 35 (3) 2005: pp.152-16

Genetic evaluation of suspected osteogenesis imperfecta (OI)

Osteogenesis imperfecta (OI) is probably the most common genetic form of fracture predisposition. The term OI encompasses a broad range of clinical presentations that may be first apparent from early in pregnancies to late in life, reflecting the extent of bone deformity and fracture predisposition at different stages of development or postnatal ages. Depending on the age of presentation, OI can be difficult to distinguish from some other genetic and nongenetic causes of fractures, including nonaccidental injury (abuse). The strategies for evaluation and the testing discussed here provide guidelines for evaluation that should help to distinguish among causes for fracture and bone deformity

A review of the systematic biology of fossil and living bony-tongue fishes, Osteoglossomorpha (Actinopterygii: Teleostei)

The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these fishes, particularly with regard to the phylogenetic affinities of several fossil taxa, within Mormyridae, and the position of Pantodon. In this paper we review the state of knowledge for osteoglossomorph fishes. We first provide an overview of the diversity of Osteoglossomorpha, and then discuss studies of the phylogeny of Osteoglossomorpha from both morphological and molecular perspectives, as well as biogeographic analyses of the group. Finally, we offer our perspectives on future needs for research on the systematic biology of Osteoglossomorpha

A scoping review and thematic analysis of social and behavioural research among HIV-serodiscordant couples in high-income settings.

CAPRISA, 2015.Abstract available in pdf

Genetic varaiation within and differentiation between Pseudobarbus quathlambae (Pisces, Cyprinidae) populations from the Senqunyane, Jordane and Bokong Rivers (Central Lesotho)

Horizontal starch-gel electrophoresis was used to obtain baseline genetic information on critically endangered Pseudobarbus quathlambae populations in the Senqunyane, Jordane and Bokong Rivers in the Lesotho Highlands. Allelic frequencies were similar between the populations and generations studied. However, allele classes at a large number of polymorphic loci deviated from expected proportions, probably as a result of inbreeding, brought about by isolation in upper catchment streams. Average heterozygosity values range from 4.2—6.2% and the average genetic distance between the populations is 0.008. Gene flow between populations and between generations is good and the populations in the study area can be regarded as a single large population. Keywords: Pseudobarbus quathlambae; allozyme; polymorphism; genetic distance (Afr J Aqua Sci: 2001 26(1): 23-29

Allozyme variation in two populations of Hydrocynus vittatus(Pisces, Characidae)

No Abstract

Allozyme variation in African elephant ( Loxodonta africana) from the Kruger National Park, South Africa

No Abstract