The major transition to eusociality required the evolution of a switch to canalize development into either a reproductive or a helper, the nature of which is currently unknown. Following predictions from the 'theory of facilitated variation', we identify sex differentiation pathways as promising candidates because of their pre-adaptation to regulating development of complex phenotypes. We show ...

PURPOSE The precise molecular cues required for photoreceptor development are still unknown. Pax6 and Crx are essential during early retinal development and for photoreceptor differentiation, respectively. The lipid molecule docosahexaenoic acid (DHA) has also been shown to promote photoreceptor differentiation. Pax6 expression during the early steps in photoreceptor development and whether the...

Intracellular redox potential of skeletal muscle becomes progressively more oxidized with aging, negatively impacting regenerative ability. We examined the effects of oxidizing redox potential on terminal differentiation of cultured C2C12 myoblasts. Redox potentials were manipulated by changing the culture O(2) environment, by free radical scavenging, or addition of H(2)O(2.) Intracellular reac...

A unified theory of cell differentiation, aging, and cancer is discussed. All cells are hypothesized to originate from stem cells. These stem cells mature as they divide and eventually reach a fully differentiated cell, which cannot divide. Aging is caused by the loss of stem cells, either due to cell death or terminal differentiation, and by eventual death of fully differentiated cells. Both l...

Transmission represents a population bottleneck in the Plasmodium life cycle and a key intervention target of ongoing efforts to eradicate malaria. Sexual differentiation is essential for this process, as only sexual parasites, called gametocytes, are infective to the mosquito vector. Gametocyte production rates vary depending on environmental conditions, but external stimuli remain obscure. He...

T cells are central players in the regulation of adaptive immunity and immune tolerance. In the periphery, T cell differentiation for maturation and effector function is regulated by a number of factors. Various factors such as antigens, co-stimulation signals, and cytokines regulate T cell differentiation into functionally specialized effector and regulatory T cells. Other factors such as nutr...

background: in the field of cellular therapy, the impact of confluence degree on harvesting or differentiation of bmmscs and the effect of cell-to-cell contact remain controversial. therefore, the effect of confluence on properties of bmmscs was studied and efficiency of confluence-associated osteogenic differentiation was identified. materials and methods: the impact of 20, 50, 70, 80 and 100%...

the characteristics of cellular and molecular mechanisms associated with cell proliferation and differentiation is important to understand malignancy. in this report we characterise a leukemic model, d5a1, to study the action of differentiation agent, cellular events and gene expression of the selected transcription factors. cells induced with 4 mm hexamethylene bisacetamide (hmba) caused signs...

objective(s): studies have confirmed that microgravity, as a mechanical factor, influences both differentiation and function of mesenchymal stem cells. here we investigated the effects of simulated microgravity on neural differentiation of human adipose-derived stem cells (adscs). materials and methods:we have used a fast rotating clinostat (clinorotation) to simulate microgravity condition. re...

background: vhl (von hippel-lindau), runx-3 (runt-related transcription factor 3), e-cadherin (epithelial cadherin), p15 (ink4a, cyclin dependent kinase inhibitor), and p16 (ink4b) genes are essential in hematopoiesis. the aim of this study was to explore the correlation between gene expression and promoter methylation in cd34+ stem cells before and after differentiation to erythroid lineage. m...