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Barros, C.

Publications and source records attributed to Barros, C..

3 recordsLinked to original sources

Expert-led priorities for a response diversity research agenda in ecology

Response diversity aims to capture and explain the variation in ecological responses to environmental change. Response diversity is expected to drive ecological stability since a wider variety of responses to one or more environmental factors should stabilise fluctuations of ecosystem functions. However, uptake of empirical response diversity research has been slow. Here we assess current thinking around response diversity by conducting a targeted expert survey of response diversity researchers. Our survey revealed that one barrier to a unified research agenda on response diversity is the lack of agreement among respondents on the definition of response diversity, and to which dimension(s) of ecological stability response diversity might relate. When asked to select the temporal, spatial, and biological scales at which response diversity may be most relevant for ecological stability, respondents chose a wide range of scales indicating differences in how experts view response diversitys stabilising effect. Respondents considered studies incorporating both biotic interactions and abiotic environmental responses to be especially challenging, as were those thinking about responses to multiple environmental changes simultaneously. Moreover, respondents thought inconsistencies in the definitions of, and methods for measuring, response diversity were a major challenge facing the field. Despite these barriers, the survey revealed a desire for globally coordinated research efforts on response diversity in the form of syntheses, workshops, and distributed experiments, but that a standardised response diversity metric across diverse use-cases could be too restrictive. Our findings suggest we can shift response diversity from a loose collection of conceptual studies and inconsistent empirical applications towards a quantitative and coordinated research programme mechanistically linking biodiversity and ecological stability. As such, we are launching the Response Diversity Network--a research community interested in the science and application of response diversity-- whose activities we hope will benefit both individual studies of response diversity and globally coordinated research efforts.

ecology↗

DNA damage and macrophage infiltration in the ovaries of the long-lived GH deficient Ames Dwarf and the short-lived bGH transgenic mice

ObjectiveThe aim of the study was to evaluate the role of growth hormone (GH) in DNA damage, macrophage infiltration and the granulosa cells number of primordial and primary follicles. MethodsFor these experiments six groups of female mice were used. Four groups consisted of Ames dwarf (Prop-1df, df/df, n=12) and their normal littermates (N/df, n=12) mice, between sixteen and eighteen month-old, receiving GH (n=6 for df/df, and n=6 for N/df mice) or saline injections (n=6 for df/df, and n=6 for N/df mice). The other two groups consisted of ten to twelve-month-old bGH (n=6) and normal mice (N, n=6). Immunofluorescence for DNA damage (anti-{gamma}H2AX) and macrophage counting (anti-CD68) were performed. Granulosa cells of primordial and primary follicles were counted. ResultsFemale df/df mice had lower {gamma}H2AX foci intensity in in both oocytes and granulosa cells of primordial and primary follicles (p<0.05), indicating less DNA double strand breaks (DSBs). In addition, GH treatment increased DSBs in both df/df and N/df mice. Inversely, bGH mice had higher quantity of DSBs in both oocytes and granulosa cells of primordial and primary follicles (p<0.05). Df/df mice showed ovarian tissue with less macrophage infiltration than N/df mice (p<0.05) and GH treatment increased macrophage infiltration (p<0.05). On the other hand, bGH mice had ovarian tissue with more macrophage infiltration compared to normal mice (p<0.05). Df/df mice had less granulosa cells on primordial and primary follicles than N/df mice (p<0.05). GH treatment did not affect the granulosa cells number (p>0.05). However, bGH mice had an increased number of granulosa cells on primordial and primary follicles compared to normal mice (p<0.05). ConclusionThe current study points to the role of the GH/IGF-I axis in maintenance of oocyte DNA integrity and macrophage ovarian infiltration in mice.

physiology↗

A zinc-finger fusion protein refines Gal4-defined neural circuits

The analysis of behavior requires that the underlying neuronal circuits are identified and genetically isolated. In several major model species--most notably Drosophila, neurogeneticists identify and isolate neural circuits with a binary heterologous expression-control system: Gal4-UASG. One limitation of Gal4-UASG is that expression patterns are often too broad to map circuits precisely. To help refine the range of Gal4 lines, we developed an intersectional genetic AND operator. Interoperable with Gal4, the new systems key component is a fusion protein in which the DNA-binding domain of Gal4 has been replaced with a zinc finger domain with a different DNA-binding specificity. In combination with its cognate binding site (UASZ) the zinc-finger-replaced Gal4 ( Zal1) was functional as a standalone transcription factor. Zal1 transgenes also refined Gal4 expression ranges when combined with UASGZ, a hybrid upstream activation sequence. In this way, combining Gal4 and Zal1 drivers captured restricted cell sets compared with single drivers and improved genetic fidelity. This intersectional genetic AND operation presumably derives from the action of a heterodimeric transcription factor: Gal4-Zal1. Configurations of Zal1-UASZ and Zal1-Gal4-UASGZ are versatile tools for defining, refining, and manipulating targeted neural expression patterns with precision.

neuroscience↗