title: Retroviruses in the common brush-tailed possum (Trichosurus vulpecula)

authors: Baillie, Gregory John

abstract: This study details the search for, and characterisation of, retroviruses in a marsupial, the common brush-tailed possum (Trichosurus vulpecula). Initial efforts were directed at detecting exogenous retroviruses in possums, but the majority of the work described in this thesis involved the isolation and characterisation of a possum endogenous retrovirus.

Endogenous retroviruses were detected in possum genomic DNA by PCR amplification using degenerate primers derived from the retroviral pol gene. Cloning, sequencing, and analysis of these PCR products revealed the presence of several families of endogenous retroviruses in the possum genome.

Reverse transcriptase activity was detected in the blood of all possums tested using the product enhanced reverse transcriptase (PERT) assay. RT-PCR was performed on RNA isolated from possum blood plasma using the pol-derived degenerate primers. Cloning and sequencing of the products indicated that a homogeneous retroviral RNA species was present in the blood of possums, and that this RNA was related to, but not identical to, the endogenous possum retroviruses already detected.

A 3'-RACE approach was used to amplify the majority of the 3' end of the possum retroviral RNA. The subsequent discovery that this RNA species was derived from an endogenous retrovirus in the possum genome allowed amplification of the remainder of the genome by a combination of PCR, single primer PCR, and RT-PCR. The sequences were assembled into a contiguous sequence, the TvERV-K1 contig. In addition, a near-full-length TvERV-K1-related fragment, was amplified from possum genomic DNA, cloned, and sequenced. It was named pTvERV-K2. The TvERV-K elements are the first full-length marsupial retrovirus sequences to be reported.

Analysis of the sequences of the TvERV-K1 contig and pTvERV-K2 revealed most of the regulatory regions required for replication of a retroviral genome, as well as uninterrupted, or minimally interrupted, open reading frames (ORFs) for the gag, pro, and pol genes. Only a short region of sequence with homology to the Env proteins of other retroviruses was detected. All of the TvERV-K proteins displayed highest homology to those of the simian type D retroviruses. Likewise, phylogenetic analysis using the deduced amino acid sequences of the Pro and Pol proteins, placed the possum endogenous retrovirus with the exogenous and endogenous type D retroviruses of Old World and New World monkeys. Thus, a cross-species transmission event - from marsupials to primates, from primates to marsupials, or from an unidentified source to both marsupials and primates - appears to have occurred.

There are 15-20 copies of the TvERV-K element in the possum genome, as determined by Southern hybridisation. However, integration sites appeared to be variable between possums, suggesting recent (or ongoing) retrotranspositional activity. Both PCR and Southern hybridisation analyses suggest that TvERV-K elements shorter than those from which the TvERV-K1 contig and pTvERV-K2 were derived are present in the possum genome. 

The implications of these findings are discussed.

text: Retroviruses in the common brush-tailed possum (Trichosurus vulpecula) This study details the search for, and characterisation of, retroviruses in a marsupial, the common brush-tailed possum (Trichosurus vulpecula). Initial efforts were directed at detecting exogenous retroviruses in possums, but the majority of the work described in this thesis involved the isolation and characterisation of a possum endogenous retrovirus.

Endogenous retroviruses were detected in possum genomic DNA by PCR amplification using degenerate primers derived from the retroviral pol gene. Cloning, sequencing, and analysis of these PCR products revealed the presence of several families of endogenous retroviruses in the possum genome.

Reverse transcriptase activity was detected in the blood of all possums tested using the product enhanced reverse transcriptase (PERT) assay. RT-PCR was performed on RNA isolated from possum blood plasma using the pol-derived degenerate primers. Cloning and sequencing of the products indicated that a homogeneous retroviral RNA species was present in the blood of possums, and that this RNA was related to, but not identical to, the endogenous possum retroviruses already detected.

A 3'-RACE approach was used to amplify the majority of the 3' end of the possum retroviral RNA. The subsequent discovery that this RNA species was derived from an endogenous retrovirus in the possum genome allowed amplification of the remainder of the genome by a combination of PCR, single primer PCR, and RT-PCR. The sequences were assembled into a contiguous sequence, the TvERV-K1 contig. In addition, a near-full-length TvERV-K1-related fragment, was amplified from possum genomic DNA, cloned, and sequenced. It was named pTvERV-K2. The TvERV-K elements are the first full-length marsupial retrovirus sequences to be reported.

Analysis of the sequences of the TvERV-K1 contig and pTvERV-K2 revealed most of the regulatory regions required for replication of a retroviral genome, as well as uninterrupted, or minimally interrupted, open reading frames (ORFs) for the gag, pro, and pol genes. Only a short region of sequence with homology to the Env proteins of other retroviruses was detected. All of the TvERV-K proteins displayed highest homology to those of the simian type D retroviruses. Likewise, phylogenetic analysis using the deduced amino acid sequences of the Pro and Pol proteins, placed the possum endogenous retrovirus with the exogenous and endogenous type D retroviruses of Old World and New World monkeys. Thus, a cross-species transmission event - from marsupials to primates, from primates to marsupials, or from an unidentified source to both marsupials and primates - appears to have occurred.

There are 15-20 copies of the TvERV-K element in the possum genome, as determined by Southern hybridisation. However, integration sites appeared to be variable between possums, suggesting recent (or ongoing) retrotranspositional activity. Both PCR and Southern hybridisation analyses suggest that TvERV-K elements shorter than those from which the TvERV-K1 contig and pTvERV-K2 were derived are present in the possum genome. 

The implications of these findings are discussed.

year: 1999

title: Untying of hands: Working migrants as social agents

authors: Medel, Coni

subjects: working migrant

abstract: This research elicited in-depth settlement experiences from long-term working migrants who migrated to Aotearoa New Zealand, interpreted through an ecological perspective on immigration. The purpose of this study was to provide a contextualised understanding of working migrants’ experiences as social agents. Immigration policies in New Zealand are primarily formulated to extract the economic benefits of migrant labour and to satisfy workforce shortages in certain industries (Terruhn & Cassim, 2023). At the same time, mainstream psychological literature usually focuses on the individual process of ‘acculturation’, describing how migrants adapt and cope in the new place of living (Berry, 2001; Ward, 2001). The community psychology approach in this research focused on addressing the societal conditions surrounding immigrants' difficulties in settling (Birman & Bray, 2017). This research explored how migrants' settlement experiences are shaped by these broader societal dimensions, examining both the resources that helped migrants to become settled and the barriers that made participation difficult.
This research took a case-based study approach. Five working migrants were interviewed about their experiences of the labour market and navigating the immigration system in their real-life contexts. In this study I explored the precarity of migrant workers, regulatory constraints on the labour market, cases of work exploitation but also constructive employment relationship experiences. This research showed that the individual stories and trajectories of migrant workers cannot be comprehended without considering their context. The findings reflected the heterogeneity and diversity of experiences for working migrants. Not all of their experiences were negative, although there were common threads linked with their precarious migrant status. Working migrants in this study experienced a loss of power, autonomy and social status as migrants, and at some point, in their migratory journey, they all sought to move out of their temporariness and precarity, so they could build their lives with more agency.
Working migrants in this study experienced a precarious migrant status due to the regulatory immigration policies that they were subjected to. The main factors of this precarious migrant status arose from their restricted movement in the labour market and a long-lasting uncertain temporal status. Participants affected by their precarious migrant status pursued more autonomy to be able to learn new skills or enhance their existing skills, which opened new opportunities for them in the labour market and also offered broader contributions to the community. This sense of agency also contributed to their personal growth. Working migrants’ experiences extended beyond their workplaces and encompassed broader social spaces. These experiences included participation in the health and housing system, together with achieving a greater work/life balance. Supportive employment relationships, stable and prosperous working conditions and social support led working migrants to develop a sense of home and a sense of meaning in their migration journeys. Permanent settlement was not a primary settlement objective for four working migrants in this study. However, all working migrants shared a need to gain more agency and autonomy. The findings of this study
tentatively suggest that granting working migrants more/full participation may have benefits that outweigh the costs that immigration policies intend to prevent. Through this thesis and by acknowledging the stories of my participants I showed that with the appropriate support, migrants can contribute fully to the receiving community and at the same time improve their well-being significantly.

text: Untying of hands: Working migrants as social agents This research elicited in-depth settlement experiences from long-term working migrants who migrated to Aotearoa New Zealand, interpreted through an ecological perspective on immigration. The purpose of this study was to provide a contextualised understanding of working migrants’ experiences as social agents. Immigration policies in New Zealand are primarily formulated to extract the economic benefits of migrant labour and to satisfy workforce shortages in certain industries (Terruhn & Cassim, 2023). At the same time, mainstream psychological literature usually focuses on the individual process of ‘acculturation’, describing how migrants adapt and cope in the new place of living (Berry, 2001; Ward, 2001). The community psychology approach in this research focused on addressing the societal conditions surrounding immigrants' difficulties in settling (Birman & Bray, 2017). This research explored how migrants' settlement experiences are shaped by these broader societal dimensions, examining both the resources that helped migrants to become settled and the barriers that made participation difficult.
This research took a case-based study approach. Five working migrants were interviewed about their experiences of the labour market and navigating the immigration system in their real-life contexts. In this study I explored the precarity of migrant workers, regulatory constraints on the labour market, cases of work exploitation but also constructive employment relationship experiences. This research showed that the individual stories and trajectories of migrant workers cannot be comprehended without considering their context. The findings reflected the heterogeneity and diversity of experiences for working migrants. Not all of their experiences were negative, although there were common threads linked with their precarious migrant status. Working migrants in this study experienced a loss of power, autonomy and social status as migrants, and at some point, in their migratory journey, they all sought to move out of their temporariness and precarity, so they could build their lives with more agency.
Working migrants in this study experienced a precarious migrant status due to the regulatory immigration policies that they were subjected to. The main factors of this precarious migrant status arose from their restricted movement in the labour market and a long-lasting uncertain temporal status. Participants affected by their precarious migrant status pursued more autonomy to be able to learn new skills or enhance their existing skills, which opened new opportunities for them in the labour market and also offered broader contributions to the community. This sense of agency also contributed to their personal growth. Working migrants’ experiences extended beyond their workplaces and encompassed broader social spaces. These experiences included participation in the health and housing system, together with achieving a greater work/life balance. Supportive employment relationships, stable and prosperous working conditions and social support led working migrants to develop a sense of home and a sense of meaning in their migration journeys. Permanent settlement was not a primary settlement objective for four working migrants in this study. However, all working migrants shared a need to gain more agency and autonomy. The findings of this study
tentatively suggest that granting working migrants more/full participation may have benefits that outweigh the costs that immigration policies intend to prevent. Through this thesis and by acknowledging the stories of my participants I showed that with the appropriate support, migrants can contribute fully to the receiving community and at the same time improve their well-being significantly.

year: 2024

title: Te Mātaiaho as curricular justice?

authors: Shafer, Derek

abstract: Te Mātaiaho produces a version of curricular justice which aims to give effect to Te Tiriti and address long-standing inequities in education in Aotearoa New Zealand. We examine Te Mātaiaho’s vision for subject English and its construction of students’ identities as fundamental to a curriculum that advances both bicultural nationhood and just outcomes for all students. We draw on Raewyn Connell’s (2010) model of curricular justice, and Nancy Fraser's (2017) notion of progressive neoliberalism to explore the opportunities and implications for subject English within Te Mātaiaho's vision. How might these frameworks for justice help to critique the development of educational policy and support the implementation of Te Mātaiaho's vision for biculturalnationhood and just outcomes for all students.

text: Te Mātaiaho as curricular justice? Te Mātaiaho produces a version of curricular justice which aims to give effect to Te Tiriti and address long-standing inequities in education in Aotearoa New Zealand. We examine Te Mātaiaho’s vision for subject English and its construction of students’ identities as fundamental to a curriculum that advances both bicultural nationhood and just outcomes for all students. We draw on Raewyn Connell’s (2010) model of curricular justice, and Nancy Fraser's (2017) notion of progressive neoliberalism to explore the opportunities and implications for subject English within Te Mātaiaho's vision. How might these frameworks for justice help to critique the development of educational policy and support the implementation of Te Mātaiaho's vision for biculturalnationhood and just outcomes for all students.

year: 2023-11-22