Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

Variation and distribution in temporalis muscle innervation

$\bf Background$ Despite extensive discourse on the utilisation of the temporal muscle for facial reanimation, anatomical description regarding the innervation of its motor nerve branches is incomplete and varied. This systematic review aimed to consolidate the existing evidence concerning the distribution and variation in the pattern of temporalis innervation. $\bf Methods$ A PRISMA-compliant systematic literature search was conducted in November 2023 and included studies offering anatomical insights into the distribution and variation of temporalis innervation patterns. Multiple category prevalence and proportional meta-analysis were conducted. $\bf Results$ The initial search yielded 978 results, from which 13 studies were selected for inclusion. The inferior anterior temporalis muscle region was found to receive innervation from the buccal nerve's superior branch and inferior posterior region from the masseteric nerve. In the superior part, comprising anterior, middle and posterior regions, innervation is provided by the branches of the deep temporal nerve (DTN) arising from various branches of the mandibular or masseteric nerves. Analysis revealed that the most common variation of DTN was the presence of two branches (46%, 95% CI: 46%-63%, I$\^{2}$=94%), followed by three branches (26%, 95% CI: 24%-39%). Subgroup analyses of 86 patients indicated high prevalence rates of innervation by the temporal branches of the buccal nerve (85%, 95% CI: 76%-92%, I$\^{2}$=98%) and temporal branches of the masseteric nerve (72%, 95% CI: 63%-81%, I$\^{2}$=90%). $\bf Conclusion$ In conclusion, this systematic review and meta-analysis highlight the evolving understanding and complexities of temporalis innervation, revealing the variations in nerve branches and emphasising the need for further research

Expression pattern of heat shock proteins during acute thermal stress in the Antarctic sea urchin, Sterechinus neumayeri

© 2016 González et al. Background: Antarctic marine organisms have evolved a variety of physiological, life-history and molecular adaptations that allow them to cope with the extreme conditions in one of the coldest and most temperaturestable marine environments on Earth. The increase in temperature of the Southern Ocean, product of climate change, represents a great challenge for the survival of these organisms. It has been documented that some Antarctic marine invertebrates are not capable of generating a thermal stress response by means of an increase in the synthesis of heat shock proteins, which could be related with their low capacity for acclimatization. In order to understand the role of heat shock proteins as a compensatory response in Antarctic marine species to projected scenarios of increased seawater temperatures, we assessed the expression of the genes Hsp90, Grp78, Hyou1 and Hsc70 in the Antarctic sea urchin Sterechinus neumayeri under three thermal treatments (1 °C, 3 °C and 5 °C), for a period of exposure of 1, 24 and 48 h. Results: The results obtained showed that these genes were expressed themselves in all of the tissues analyzed in a constitutive form. During acute thermal stress, an overexpression of the Hsp90, Grp78 and Hyou1 genes was observed in coelomocyte samples at 3 °C after 48 h, while in esophageal samples, an increase in Hsp90 and Grp78 expression was observed after 48 h. Thermal stress at 5 °C, in general, did not produce a significant increase in the expression of the genes that were studied. The expression of Hsp70 did not show modifications in its expression as a result of thermal stress. Conclusions: S. neumayeri is capable of overe xpressing stress proteins as a result of thermal stress, however, this response is delayed and to a lesser degree compared to other Antarctic or temperate species. These results indicate that adult individuals could cope with the expected impacts caused by an increase in coastal sea temperatures in the Southern Ocean.Link_to_subscribed_fulltex