title: A new experimental model for the investigation of sequential hermaphroditism

authors: Goikoetxea, A

subjects: Science & Technology

abstract: The stunning sexual transformation commonly triggered by age, size or social context in some fishes is one of the best examples of phenotypic plasticity thus far described. To date our understanding of this process is dominated by studies on a handful of subtropical and tropical teleosts, often in wild settings. Here we have established the protogynous New Zealand spotty wrasse, Notolabruscelidotus, as a temperate model for the experimental investigation of sex change. Captive fish were induced to change sex using aromatase inhibition or manipulation of social groups. Complete female-to-male transition occurred over 60 days in both cases and time-series sampling was used to quantify changes in hormone production, gene expression and gonadal cellular anatomy. Early-stage decreases in plasma 17β-estradiol (E2) concentrations or gonadal aromatase (cyp19a1a) expression were not detected in spotty wrasse, despite these being commonly associated with the onset of sex change in subtropical and tropical protogynous (female-to-male) hermaphrodites. In contrast, expression of the masculinising factor amh (anti-Müllerian hormone) increased during early sex change, implying a potential role as a proximate trigger for masculinisation. Collectively, these data provide a foundation for the spotty wrasse as a temperate teleost model to study sex change and cell fate in vertebrates.

text: A new experimental model for the investigation of sequential hermaphroditism The stunning sexual transformation commonly triggered by age, size or social context in some fishes is one of the best examples of phenotypic plasticity thus far described. To date our understanding of this process is dominated by studies on a handful of subtropical and tropical teleosts, often in wild settings. Here we have established the protogynous New Zealand spotty wrasse, Notolabruscelidotus, as a temperate model for the experimental investigation of sex change. Captive fish were induced to change sex using aromatase inhibition or manipulation of social groups. Complete female-to-male transition occurred over 60 days in both cases and time-series sampling was used to quantify changes in hormone production, gene expression and gonadal cellular anatomy. Early-stage decreases in plasma 17β-estradiol (E2) concentrations or gonadal aromatase (cyp19a1a) expression were not detected in spotty wrasse, despite these being commonly associated with the onset of sex change in subtropical and tropical protogynous (female-to-male) hermaphrodites. In contrast, expression of the masculinising factor amh (anti-Müllerian hormone) increased during early sex change, implying a potential role as a proximate trigger for masculinisation. Collectively, these data provide a foundation for the spotty wrasse as a temperate teleost model to study sex change and cell fate in vertebrates.

year: 2021-12-01

title: Bringing Antarctica to the lab: a polar desert environmental chamber to study the response of Antarctic microbial communities to climate change

authors: Monteiro, Maria R.

abstract: Polar deserts contain unique and sensitive communities responsive to climate-associated habitat changes. However, unlike temperate desert ecosystems, characterizing and predicting the responses of polar ecosystems to environmental change remains a significant challenge due to logistical constraints. Here we aim to demonstrate the use of a custom-designed Polar Desert Environmental Chamber (PDEC) to perform off-continent experimental ecological research. We did so by characterizing the structure and composition of arid edaphic bacterial communities collected from the McMurdo Dry Valleys during a simulated wetting event. The results were discussed in light of previous field observations. Rapid structural and compositional changes were observed during wetting and re-drying treatments. Those were driven by changes in the relative abundance of coexisting taxa, which fluctuated asynchronously over time in response to the treatments. While selection was the main ecological factor influencing communities during dry conditions or the initial wetting, with prolonged exposure to wetness, neutral processes began to drive community assembly. Ultimately, these observations reflect different adaptative responses from microbial taxa to water stress, which can be argued as beneficial to increasing resilience in polar deserts. Our findings demonstrate that experiments conducted in PDEC provide valuable contextual data on community response to environmental change and can accelerate our ability to assess biological thresholds to change within polar desert ecosystems. We advocate that, with careful consideration of key emulated environmental attributes, laboratory-based Antarctic research can complement fieldwork to achieve a nuanced and evidence-based understanding of the ecology of Antarctica’s ice-free regions.

text: Bringing Antarctica to the lab: a polar desert environmental chamber to study the response of Antarctic microbial communities to climate change Polar deserts contain unique and sensitive communities responsive to climate-associated habitat changes. However, unlike temperate desert ecosystems, characterizing and predicting the responses of polar ecosystems to environmental change remains a significant challenge due to logistical constraints. Here we aim to demonstrate the use of a custom-designed Polar Desert Environmental Chamber (PDEC) to perform off-continent experimental ecological research. We did so by characterizing the structure and composition of arid edaphic bacterial communities collected from the McMurdo Dry Valleys during a simulated wetting event. The results were discussed in light of previous field observations. Rapid structural and compositional changes were observed during wetting and re-drying treatments. Those were driven by changes in the relative abundance of coexisting taxa, which fluctuated asynchronously over time in response to the treatments. While selection was the main ecological factor influencing communities during dry conditions or the initial wetting, with prolonged exposure to wetness, neutral processes began to drive community assembly. Ultimately, these observations reflect different adaptative responses from microbial taxa to water stress, which can be argued as beneficial to increasing resilience in polar deserts. Our findings demonstrate that experiments conducted in PDEC provide valuable contextual data on community response to environmental change and can accelerate our ability to assess biological thresholds to change within polar desert ecosystems. We advocate that, with careful consideration of key emulated environmental attributes, laboratory-based Antarctic research can complement fieldwork to achieve a nuanced and evidence-based understanding of the ecology of Antarctica’s ice-free regions.

year: 2023-05-01

title: Hangarau me te Māori: Māori and technology

authors: Keegan, Te Taka Adrian Gregory

subjects: Māori

abstract: A sign of a vibrant, healthy developing nation is the adaptation and uptake of new technologies. Māori have a long, but mostly unrecognised, history of ingenious innovation and adaption of new technologies. This chapter will reveal Māori ingenuity through discussion of historic examples and modern media usages by Māori, and the future implications these have for Māori.
Technology can be defined as tools, devices and machines that have been developed by the application of scientific knowledge. Māori technology, then, is Māori tools, devices and machines that have been developed by the application of Māori scientific knowledge. This chapter discusses some examples of innovative Māori technology and their adoption in both historic and modern times. It includes sections on historic Māori technology, Māori media innovation and Māori adoption of Internet technology. Two sections are further expanded on: Māori in social networking sites and te reo Māori in technology. The chapter concludes with the authors' thoughts on how the adoption of new technologies will shape tikanga Māori and te reo Māori into the future.

text: Hangarau me te Māori: Māori and technology A sign of a vibrant, healthy developing nation is the adaptation and uptake of new technologies. Māori have a long, but mostly unrecognised, history of ingenious innovation and adaption of new technologies. This chapter will reveal Māori ingenuity through discussion of historic examples and modern media usages by Māori, and the future implications these have for Māori.
Technology can be defined as tools, devices and machines that have been developed by the application of scientific knowledge. Māori technology, then, is Māori tools, devices and machines that have been developed by the application of Māori scientific knowledge. This chapter discusses some examples of innovative Māori technology and their adoption in both historic and modern times. It includes sections on historic Māori technology, Māori media innovation and Māori adoption of Internet technology. Two sections are further expanded on: Māori in social networking sites and te reo Māori in technology. The chapter concludes with the authors' thoughts on how the adoption of new technologies will shape tikanga Māori and te reo Māori into the future.

year: 2018