Defining the centromere

Centromeres are the chromosomal domains at which the kinetochore, a protein complex required for the correct separation of chromosomes during mitosis and meiosis, is assembled. The incorporation of the histone variant CenH3 into centromeric nucleosomes is a prerequisite for the proper assembly and function of the kinetochore. A new study describes the chaperone protein NASPSIM3 and how it affects the depositioning of CenH3.

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Limiting mealtimes may increase your motivation for exercise

Limiting access to food in mice increases levels of the hormone, ghrelin, which may also increase motivation to exercise, according to a new study. The study suggests that a surge in levels of appetite-promoting hormone, ghrelin, after a period of fasting prompted mice to initiate voluntary exercise.

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First report of cotton blue disease in the United States

Reported from six counties in coastal Alabama in 2017, cotton blue disease affected approximately 25% of the state's cotton crop and caused a 4% yield loss. The disease was reported again in 2018, affecting 3-100% of cotton fields in Alabama but causing only a 1% yield loss. Symptoms, which include slowed plant growth, loss of chlorophyll, and dwarfing of infected leaves, usually do not appear until last August after full bloom. To date, there are no recommended strategies for management of this disease.

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Newly identified compounds could help give fire ants their sting

Native to South America, imported fire ants have now spread to parts of North America and elsewhere around the world. These invasive pests have painful stings that, in some cases, can cause serious medical problems, such as hypersensitivity reactions, infections and even kidney failure. Now, researchers have identified pyridine alkaloids that, along with other venom components, could contribute to these conditions.

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How hunger makes food tastier: A neural circuit in the hypothalamus

Using optogenetic and chemogenetic techniques, researchers have identified brain circuits underlying hunger-induced changes in the preferences for sweet and aversive tastes in mice. These circuits involved Agouti-related peptide-expressing neurons, which projected to glutamate neurons in the lateral hypothalamus. From there, glutamate neurons projecting to the lateral septum increased sweetness preferences, and glutamate neurons projecting to the lateral habenula decreased sensitivity to aversive tastes.

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