Sex determination shows a great diversity of mechanisms, ranging from temperature and other environmental cues to strict chromosomal control over this process. In the case of genetic sex determination, this variability is linked to a similarly high variation of sex chromosome differentiation. In vertebrates the most widespread situation is that a pair of sex chromosomes differs in males and fem...

DHEA is the major precursor of human sex steroid synthesis and is inactivated via sulfonation to DHEAS. A previous genome-wide association study related the single nucleotide polymorphism (SNP) rs2637125, located near the coding region of DHEA sulfotransferase, SULT2A1, to serum DHEAS concentrations. However, the functional relevance of this SNP with regard to DHEA sulfonation is unknown. Using...

Apolipoprotein E (ApoE) is one of the most extensively studied genes in the context of aging, but there are few population-based studies on ApoE polymorphism in the elderly in developing countries. The objective of the present study was to assess ApoE allele and genotype distribution in a large elderly community-based sample and its association with age, sex and skin color. Participants include...

OBJECTIVES To test whether age, sex, body mass index (BMI), and the apolipoprotein E (APOE) genotype are associated with the metabolic response to an n-3 polyunsaturated fatty acid (PUFA) supplementation. METHODS 210 subjects followed a 2-week run-in period based on Canada's Food Guide and underwent a 6-week 5 g/day fish oil supplementation (1.9 g of eicosapentaenoic acid and 1.1 g of docosah...

BACKGROUND & AIMS In the Netherlands, a selective hepatitis B virus (HBV) vaccination programme started in 2002 for men having sex with men, drug users, commercial sex workers and heterosexuals with frequent partner changes. We assessed the programme's effectiveness to guide policy on HBV prevention. METHODS We analysed reports of acute HBV infection in the Netherlands between 2004 and 2010 r...

AIMS Polymorphisms in CYP2C9 and VKORC1 influence patients' phenprocoumon (PHE) and acenocoumarol (ACE) dose requirements. To provide physicians with tools to estimate the patient's individual dose, we aimed to develop algorithms for PHE and ACE. METHODS AND RESULTS In two Dutch anticoagulation clinics, data on age, sex, height, weight, co-medication, coumarin derivative doses, and internatio...

Histone macroH2A1.2 and the murine heterochromatin protein 1, HP1 beta, have both been implicated in meiotic sex chromosome inactivation (MSCI) and the formation of the XY-body in male meiosis. In order to get a closer insight into the function of histone macroH2A1.2 we have investigated the localisation of macroH2A1.2 in surface spread spermatocytes from normal male mice and in oocytes of XX a...

Specimens of Hoplias malabaricus from Lagoa Carioca, an isolated lake of the Rio Doce State Park (state of Minas Gerais, Brazil), were cytogenetically studied. The diploid number was found to be constant, i.e., 2n = 42 chromosomes, although two karyotypic forms were found: karyotype A, characterized by 22M + 20SM chromosomes, observed only in a male specimen, and karyotype B, characterized by 2...

The gametocyte sex ratio of Plasmodium mexicanum, a malaria parasite of western fence lizards, was studied in a modified garden experiment. Each of 6 naturally infected lizards was used to initiate 20 replicate-infections in naive western fence lizards. A significant donor effect was observed for the sex ratios of recipient infections at their maximal parasitemia, and this effect was associated...