Biodiversity of 52 chicken populations assessed by microsatellite typing of DNA pools

In a project on the biodiversity of chickens funded by the European Commission (EC), eight laboratories collaborated to assess the genetic variation within and between 52 populations from a wide range of chicken types. Twenty-two di-nucleotide microsatellite markers were used to genotype DNA pools of 50 birds from each population. The polymorphism measures for the average, the least polymorphic population (inbred C line) and the most polymorphic population (Gallus gallus spadiceus) were, respectively, as follows: number of alleles per locus, per population: 3.5, 1.3 and 5.2; average gene diversity across markers: 0.47, 0.05 and 0.64; and proportion of polymorphic markers: 0.91, 0.25 and 1.0. These were in good agreement with the breeding history of the populations. For instance, unselected populations were found to be more polymorphic than selected breeds such as layers. Thus DNA pools are effective in the preliminary assessment of genetic variation of populations and markers. Mean genetic distance indicates the extent to which a given population shares its genetic diversity with that of the whole tested gene pool and is a useful criterion for conservation of diversity. The distribution of population-specific (private) alleles and the amount of genetic variation shared among populations supports the hypothesis that the red jungle fowl is the main progenitor of the domesticated chicken

Theorising Women’s Health and health inequalities: shaping processes of the ‘gender-biology nexus’

Since the theoretical frameworks and conceptual tools we employ shape research outcomes by guiding research pathways, it is important that we subject them to ongoing critical reflection. A thoroughgoing analysis of the global production of women's health inequality calls for a comprehensive theorization of how social relations of gender and the biological body mutually interact in local contexts in a nexus with women's health. However, to date, the predominant concern of research has been to identify the biological effects of social relations of gender on the body, to the relative neglect of the co-constitutive role that these biological changes themselves may play in ongoing cycles of gendered health oppressions. Drawing on feminist and gender theoretical approaches, and with the health of women and girls as our focus, we seek to extend our understanding of this recursive process by discussing what we call the 'shaping processes' of the 'gender-biology nexus' which call attention to not only the 'gender-shaping of biology' but also the 'biologic-shaping of gender'. We consider female genital mutilation/cutting as an illustration of this process and conclude by proposing that a framework which attends to both the 'gender-shaping of biology' and the 'biologic-shaping of gender' as interweaving processes provides a fruitful approach to theorising the wider health inequalities experienced by women and girls

Trypanosoma vivax Infections: Pushing Ahead with Mouse Models for the Study of Nagana. I. Parasitological, Hematological and Pathological Parameters

African trypanosomiasis is a severe parasitic disease that affects both humans and livestock. Several different species may cause animal trypanosomosis and although Trypanosoma vivax (sub-genus Duttonella) is currently responsible for the vast majority of debilitating cases causing great economic hardship in West Africa and South America, little is known about its biology and interaction with its hosts. Relatively speaking, T. vivax has been more than neglected despite an urgent need to develop efficient control strategies. Some pioneering rodent models were developed to circumvent the difficulties of working with livestock, but disappointedly were for the most part discontinued decades ago. To gain more insight into the biology of T. vivax, its interactions with the host and consequently its pathogenesis, we have developed a number of reproducible murine models using a parasite isolate that is infectious for rodents. Firstly, we analyzed the parasitical characteristics of the infection using inbred and outbred mouse strains to compare the impact of host genetic background on the infection and on survival rates. Hematological studies showed that the infection gave rise to severe anemia, and histopathological investigations in various organs showed multifocal inflammatory infiltrates associated with extramedullary hematopoiesis in the liver, and cerebral edema. The models developed are consistent with field observations and pave the way for subsequent in-depth studies into the pathogenesis of T. vivax - trypanosomosis