Response of the subalpine bunchgrasses to wildfires and its effects in the relative abundance of the volcano rabbit in the Ajusco-Chichinautzin Mountain Range.

The volcano rabbit (Romerolagus diazi) is a lagomorph endemic to the central mountains of the Trans-Mexican Volcanic Belt and is classified as threatened at extinction risk. It is a habitat specialist in bunchgrass communities. The annual wildfires that occur throughout its distribution range are a vulnerability factor for the species. However, the effects of wildfires on volcano rabbit populations are not fully understood. We evaluated the occupancy and change in the volcano rabbit relative abundance index in the burned bunchgrass communities of the Ajusco-Chichinautzin Mountain Range during an annual cycle of wildfire events. Additionally, we assessed the factors that favor and limit occupation and reoccupation by the volcano rabbit using the relative abundance index in burned plots as an indicator of these processes. The explanatory factors for the response of the volcano rabbit were its presence in the nearby unburned bunchgrasses, the height of three species of bunchgrass communities, the proportion of different types of vegetation cover within a 500 m radius around the burned plots, heterogeneity of the vegetation cover, and the extent of the wildfire. Statistical analyses indicated possible reoccupation in less than a year in burned bunchgrass communities adjacent to unburned bunchgrass communities with volcano rabbits. The relative abundance index of volcano rabbits was not favored when the maximum height of the Muhlenbergia macroura bunchgrass community was less than 0.77 m. When the vegetation around the burned plots was dominated by forest (cover >30% of the buffer) and the fire was extensive, the number of latrines decreased per month but increased when the bunchgrass and shrub cover was greater around the burned plots. While the statistical results are not conclusive, our findings indicate a direction for future projects, considering extensive monitoring to obtain a greater number of samples that contribute to consolidating the models presented.

The Sonozotz project: Assembling an echolocation call library for bats in a megadiverse country.

Bat acoustic libraries are important tools that assemble echolocation calls to allow the comparison and discrimination to confirm species identifications. The Sonozotz project represents the first nation-wide library of bat echolocation calls for a megadiverse country. It was assembled following a standardized recording protocol that aimed to cover different recording habitats, recording techniques, and call variation inherent to individuals. The Sonozotz project included 69 species of echolocating bats, a high species richness that represents 50% of bat species found in the country. We include recommendations on how the database can be used and how the sampling methods can be potentially replicated in countries with similar environmental and geographic conditions. To our knowledge, this represents the most exhaustive effort to date to document and compile the diversity of bat echolocation calls for a megadiverse country. This database will be useful to address a range of ecological questions including the effects of anthropogenic activities on bat communities through the analysis of bat sound.

Nuclear localization of the dystrophin-associated protein α-dystrobrevin through importin α2/ß1 is critical for interaction with the nuclear lamina/maintenance of nuclear integrity.

Although α-dystrobrevin (DB) is assembled into the dystrophin-associated protein complex, which is central to cytoskeletal organization, it has also been found in the nucleus. Here we delineate the nuclear import pathway responsible for nuclear targeting of α-DB for the first time, together with the importance of nuclear α-DB in determining nuclear morphology. We map key residues of the nuclear localization signal of α-DB within the zinc finger domain (ZZ) using various truncated versions of the protein, and site-directed mutagenesis. Pulldown, immunoprecipitation, and AlphaScreen assays showed that the importin (IMP) α2/ß1 heterodimer interacts with high affinity with the ZZ domain of α-DB. In vitro nuclear import assays using antibodies to specific importins, as well as in vivo studies using siRNA or a dominant negative importin construct, confirmed the key role of IMPα2/ß1 in α-DB nuclear translocation. Knockdown of α-DB expression perturbed cell cycle progression in C2C12 myoblasts, with decreased accumulation of cells in S phase and, significantly, altered localization of lamins A/C, B1, and B2 with accompanying gross nuclear morphology defects. Because α-DB interacts specifically with lamin B1 in vivo and in vitro, nuclear α-DB would appear to play a key role in nuclear shape maintenance through association with the nuclear lamina.