Evaluating Gene Drive Approaches for Public Benefit

Gene drive approaches—those which bias inheritance of a genetic element in a population of sexually reproducing organisms—have the potential to provide important public benefits. The spread of selected genetic elements in wild populations of organisms may help address certain challenges, such as transmission of vector-borne human and animal diseases and biodiversity loss due to invasive animals. Adapting various naturally occurring gene drive mechanisms to these aims is a long-standing research area, and recent advances in genetics have made engineering gene drive systems significantly more technically feasible. Gene drive approaches would act through changes in natural environments, thus robust methods to evaluate potential research and use are important. Despite the fact that gene drive approaches build on existing paradigms, such as genetic modification of organisms and conventional biological control, there are material challenges to their evaluation. One challenge is the inherent complexity of ecosystems, which makes precise prediction of changes to the environment difficult. For gene drive approaches that are expected to spread spatially and/or persist temporally, responding to this difficulty with the typical stepwise increases in the scale of studies may not be straightforward after studies begin in the natural environment. A related challenge is that study or use of a gene drive approach may have implications for communities beyond the location of introduction, depending on the spatial spread and persistence of the approach and the population biology of the target organism. This poses a particular governance challenge when spread across national borders is plausible. Finally, community engagement is an important element of responsible research and governance, but effective community engagement for gene drive approaches requires addressing complexity and uncertainty and supporting representative participation in decision making. These challenges are not confronted in a void. Existing frameworks, processes, and institutions provide a basis for effective evaluation of gene drive approaches for public benefit. Although engineered gene drive approaches are relatively new, the necessities of making decisions despite uncertainty and governing actions with potential implications for shared environments are well established. There are methodologies to identify potential harms and assess risks when there is limited experience to draw upon, and these methodologies have been applied in similar contexts. There are also laws, policies, treaties, agreements, and institutions in place across many jurisdictions that support national and international decision making regarding genetically modified organisms and the potential applications of gene drive approaches, such as public health and biodiversity conservation. Community engagement is an established component of many decision-making processes, and related experience and conceptual frameworks can inform engagement by researchers. The existence of frameworks, processes, and institutions provides an important foundation for evaluating gene drive approaches, but it is not sufficient by itself. They must be rigorously applied, which requires resources for risk assessment, research, and community engagement and diligent implementation by governance institutions. The continued evolution of the frameworks, processes, and institutions is important to adapt to the growing understanding of gene drive approaches. With appropriate resources and diligence, it will be possible to responsibly evaluate and make decisions on gene drive approaches for public benefit

Consumo, calidad nutritiva y composición botánica de una pradera de alfalfa y gramíneas perennes con diferentes niveles de asignación de forraje.

The objective of the work was to evaluate the effect of the amount of forage allowance (FA), in grazing periods of 24 h, to crossbreed steers of European breeds, 235 kg initial body weight, in an alfalfa-perennial grasses pasture, on the availability of dry matter (DM), DM intake (DMI), relative feed value (RFV) and crude protein (CP) of the forage, as well as the pasture's changes in botanical composition, during the grazing. The experimental design used was a randomized complete-block design with a factorial arrangement of treatments: three FA per day (2, 4, and 7 % body weight (BW) of DM) and six sampling times (ST, 0, 3, 6, 9, 21, and 24 h), correlations and functional relationships between the response variables were also estimated. FA affected DM availability (r=-0.99), DMI (r=0.98), RFV (PEl objetivo del trabajo fue evaluar el efecto de la cantidad asignada de forraje (AF), en periodos de pastoreo de 24 h, a novillos cruzados de razas europeas con 235 kg de peso inicial, en una pradera de alfalfa-gramíneas perennes, sobre la disponibilidad y consumo de materia seca (CMS), valor relativo (VRF) y proteina cruda (PC) del forraje, así como los cambios en composición botánica de la pradera, durante el periodo de pastoreo. Se utilizó un diseño en bloques al azar con arreglo factorial de tratamientos: tres AF (2, 4 y 7 % del peso vivo (PV) en MS) y seis tiempos de muestreo (TM, 0, 3, 6, 9, 21, y 24 h), además se estimaron correlaciones y relaciones funcionales entre las variables de respuesta. La AF afectó la disponibilidad de MS (r=-0.99), el CMS (r=0.98), el VRF y la PC (