Publications by authors named "Brian McGee"

Neurocognitive screeners are used to detect symptoms of HIV-Associated Neurocognitive Disorders (HAND). However, the degree to which education and socioeconomic status affect these screeners remains unclear. Neurocognitive screeners were administered to 187 socioeconomically disadvantaged HIV+ individuals upon entering treatment who had no other risk factors for HAND.

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The bdelloid rotifer Adineta ricciae is an asexual microinvertebrate that can survive desiccation by entering an ametabolic state known as anhydrobiosis. Two late embryogenesis abundant (LEA) proteins, ArLEA1A and ArLEA1B, have been hypothesized to contribute to desiccation tolerance in these organisms, since in vitro assays suggest that ArLEA1A and ArLEA1B stabilize desiccation-sensitive proteins and membranes, respectively. To examine their functions in vivo, it is important to analyse the cellular distribution of the bdelloid LEA proteins.

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Intrinsically disordered proteins (IDPs) lack well-defined structure but are widely represented in eukaryotic proteomes. Although the functions of most IDPs are not understood, some have been shown to have molecular recognition and/or regulatory roles where their disordered nature might be advantageous. Anhydrin is an uncharacterized IDP induced by dehydration in an anhydrobiotic nematode, Aphelenchus avenae.

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Humidity has a large impact on the distribution and abundance of terrestrial invertebrates, but the molecular mechanisms governing drought resistance are not fully understood. Some attention has been given to the role of the heat shock response as a component of desiccation tolerance, but recent focus has been on the chaperone-like LEA (late embryogenesis abundant) proteins in anhydrobiotic animals. This study investigates the expression of putative LEA proteins as well as the heat shock protein Hsp70 during drought stress in soil and surface dwelling species of Collembola (springtails).

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Theory suggests it should be difficult for asexual organisms to adapt to a changing environment because genetic diversity can only arise from mutations accumulating within direct antecedents and not through sexual exchange. In an asexual microinvertebrate, the bdelloid rotifer, we have observed a mechanism by which such organisms could acquire the diversity needed for adaptation. Gene copies most likely representing former alleles have diverged in function so that the proteins they encode play complementary roles in survival of dry conditions.

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Article Synopsis
  • LEA proteins help organisms survive extreme dryness, and the larvae of the African chironomid Polypedilum vanderplanki can tolerate nearly complete desiccation by entering suspended animation.
  • Researchers isolated three cDNAs (PvLEA1, PvLEA2, and PvLEA3) from these larvae, which are linked to Group 3 LEA proteins and showed increased expression under dehydration stress.
  • The findings indicate that LEA proteins are common in invertebrates and highlight a shared strategy among animals, plants, and microorganisms to handle dehydration.
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