title: Development of genetic tools to detect three New Zealand indigenous freshwater mussels in environmental DNA

authors: Hu, Xiaoxue

subjects: digital PCR

abstract: As “ecological engineers”, freshwater mussels are key components in the freshwater ecosystem. However, surveying mussels can be challenging since mussel populations may be difficult to locate. Conventional methods for identifying mussel species are also problematic and require expertise since mussels are often morphologically cryptic. The same problems apply to New Zealand indigenous freshwater mussels. New Zealand had long been considered to have two indigenous species, Echyridella menziesii and Echyridella aucklandica, until a recent revision based on molecular evidence recognised a new species, Echyridella onekaka, which was previously mis-identified as Echyridella menziesii. Results from molecular studies have placed all three freshwater mussel species under a single genus, Echyridella, specific to New Zealand. For conservation and ecosystem management, a fast and reliable method for surveying and identifying New Zealand mussels is required.
This research aims to develop molecular tools that utilise environmental DNA (eDNA) collected from freshwater environments to detect mussel species. These tools target a widely used DNA marker, cytochrome c oxidase subunit I (COI), for species identification. The COI targets in eDNA samples are detected by digital polymerase chain reaction (dPCR) using genus-specific primers and species-specific TaqMan probes. Three species-specific assays were developed, followed by assessment of specificity and sensitivity. Assay for E. aucklandica showed high specificity and tolerance to inhibition from high levels of non-target DNA. A trial of duplexing simultaneously assays detecting E. onekaka and E. aucklandica also showed promising results. With further assessment of assays using in vivo and in situ environmental samples in the future, these techniques hold great promise for being a rapid and cost-effective method for surveying and identifying New Zealand freshwater mussels.
Additionally, to increase detection rate when target concentration in eDNA is extremely low, known mitochondrial sequences for all three species were extended through PCR and de novo sequencing to allow future manufacturing of a customised commercial target DNA enrichment kit (MYbaits). This work is necessary since known mitochondrial genomic sequences for these three species are too short to generate effective MYbaits oligos. Consensus primers were designed based on available complete mitochondrial genomes of closely related mussel species. Most consensus primers successfully amplified in PCR, and about 1700bp have been sequenced so far. Once the sequencing of extended region is completed, a MYbaits kit will be manufactured for future research.

text: Development of genetic tools to detect three New Zealand indigenous freshwater mussels in environmental DNA As “ecological engineers”, freshwater mussels are key components in the freshwater ecosystem. However, surveying mussels can be challenging since mussel populations may be difficult to locate. Conventional methods for identifying mussel species are also problematic and require expertise since mussels are often morphologically cryptic. The same problems apply to New Zealand indigenous freshwater mussels. New Zealand had long been considered to have two indigenous species, Echyridella menziesii and Echyridella aucklandica, until a recent revision based on molecular evidence recognised a new species, Echyridella onekaka, which was previously mis-identified as Echyridella menziesii. Results from molecular studies have placed all three freshwater mussel species under a single genus, Echyridella, specific to New Zealand. For conservation and ecosystem management, a fast and reliable method for surveying and identifying New Zealand mussels is required.
This research aims to develop molecular tools that utilise environmental DNA (eDNA) collected from freshwater environments to detect mussel species. These tools target a widely used DNA marker, cytochrome c oxidase subunit I (COI), for species identification. The COI targets in eDNA samples are detected by digital polymerase chain reaction (dPCR) using genus-specific primers and species-specific TaqMan probes. Three species-specific assays were developed, followed by assessment of specificity and sensitivity. Assay for E. aucklandica showed high specificity and tolerance to inhibition from high levels of non-target DNA. A trial of duplexing simultaneously assays detecting E. onekaka and E. aucklandica also showed promising results. With further assessment of assays using in vivo and in situ environmental samples in the future, these techniques hold great promise for being a rapid and cost-effective method for surveying and identifying New Zealand freshwater mussels.
Additionally, to increase detection rate when target concentration in eDNA is extremely low, known mitochondrial sequences for all three species were extended through PCR and de novo sequencing to allow future manufacturing of a customised commercial target DNA enrichment kit (MYbaits). This work is necessary since known mitochondrial genomic sequences for these three species are too short to generate effective MYbaits oligos. Consensus primers were designed based on available complete mitochondrial genomes of closely related mussel species. Most consensus primers successfully amplified in PCR, and about 1700bp have been sequenced so far. Once the sequencing of extended region is completed, a MYbaits kit will be manufactured for future research.

year: 2017

title: Being a language learner—Is that all there is?

authors: Lee, Jinah

abstract: Asian migrants are inevitably categorised as language learners. At times, it is the migrant's own definition and can be used as a support. At others, it is an imposition in two senses: it can be imposed by others and by institutions; and also acts as a hindrance to resettlement in the new country. Language learning raises issues of a sense of belonging and a sense of self-value. 
A narrative inquiry study of six Asian migrant women follows their experience as language learners over a twelve-month period, focusing on the different concepts above, as the women negotiate their identities, to finally divesting the label language learner. The findings suggest that there is a close link between a sense of belonging and a sense of self-value which influences the participants’ identity trajectories―towards valuable members of the mainstream society. The discussion poses two questions to education providers, ESL educators and policy makers: What does the image of language learner migrant do to the perception that others have of newcomers? How long is a newcomer a migrant?

text: Being a language learner—Is that all there is? Asian migrants are inevitably categorised as language learners. At times, it is the migrant's own definition and can be used as a support. At others, it is an imposition in two senses: it can be imposed by others and by institutions; and also acts as a hindrance to resettlement in the new country. Language learning raises issues of a sense of belonging and a sense of self-value. 
A narrative inquiry study of six Asian migrant women follows their experience as language learners over a twelve-month period, focusing on the different concepts above, as the women negotiate their identities, to finally divesting the label language learner. The findings suggest that there is a close link between a sense of belonging and a sense of self-value which influences the participants’ identity trajectories―towards valuable members of the mainstream society. The discussion poses two questions to education providers, ESL educators and policy makers: What does the image of language learner migrant do to the perception that others have of newcomers? How long is a newcomer a migrant?

year: 2017

title: Revitalizing Te Ika-a-Maui: Māori migration and the nation

authors: Mahuika, Nepia

subjects: Māori

abstract: Maui-Tikitiki-A-Taranga is more than simply a ‘mythic’ hero. For many he is a prominent figure in a long family line. The whakapapa that binds Māori to our tupuna is significant to the present and future, and carries with it the ‘ultimate expression’ of who we are. Maui has been described as ‘the most important culture hero in Māori mythology’, whose exploits and archetype provide precedents that Māori respond to in the present. The status of Maui within my own tribal boundaries is clear: ‘In accordance with the traditions and tikanga of Ngati Porou, we as People of this Land have been here since the beginning of time, or more aptly in the context of Aotearoa, since Maui fished up Te Ika-a-Maui (North Island). Maui-Tikitiki-a-Taranga is attributed with fishing up the North Island, raising it out of the depths of the sea, for successive generations of Māori to populate and cultivate.’ Maui’s waka, as Ngāti Porou uphold, is Nukutaimemeha, believed to be ‘cradled’ upon our ancestral mountain Hikurangi. However, there are other stories that recognize the waka as the South Island, with Stewart Island its anchor. These variations aside, the history remains a well-rehearsed one throughout the Māori world and in other parts of Polynesia.

text: Revitalizing Te Ika-a-Maui: Māori migration and the nation Maui-Tikitiki-A-Taranga is more than simply a ‘mythic’ hero. For many he is a prominent figure in a long family line. The whakapapa that binds Māori to our tupuna is significant to the present and future, and carries with it the ‘ultimate expression’ of who we are. Maui has been described as ‘the most important culture hero in Māori mythology’, whose exploits and archetype provide precedents that Māori respond to in the present. The status of Maui within my own tribal boundaries is clear: ‘In accordance with the traditions and tikanga of Ngati Porou, we as People of this Land have been here since the beginning of time, or more aptly in the context of Aotearoa, since Maui fished up Te Ika-a-Maui (North Island). Maui-Tikitiki-a-Taranga is attributed with fishing up the North Island, raising it out of the depths of the sea, for successive generations of Māori to populate and cultivate.’ Maui’s waka, as Ngāti Porou uphold, is Nukutaimemeha, believed to be ‘cradled’ upon our ancestral mountain Hikurangi. However, there are other stories that recognize the waka as the South Island, with Stewart Island its anchor. These variations aside, the history remains a well-rehearsed one throughout the Māori world and in other parts of Polynesia.

year: 2009