title: Molecular Characterisation of Sex Differentiation Genes in Yellowtail Kingfish (Seriola lalandi)

authors: Elliott, Nicholas B.

subjects: seriola

abstract: Species diversification is crucial for the successful establishment and growth of a finfish aquaculture industry in New Zealand. The yellowtail kingfish Seriola lalandi is a promising candidate species with a fast growth rate, high market value, and is successfully farmed overseas, along with several other Seriola species. To truly domesticate any farmed species, understanding reproduction is vital. Sexual differentiation is a key part of early reproductive development and is characterised by the migration of primordial germ cells through the body to the site of the presumptive gonad, where they proliferate and differentiate into spermatogonia and oogonia. A number of key genes are expressed during sex differentiation, but currently very little molecular research has been conducted on S. lalandi. 

Using bioinformatics approaches, the available gene databases and the implementation of a transcriptomic library prepared from the gonad, ovary and pituitary tissue of S. lalandi, a number of key sex differentiation genes were identified, which included, Vasa, Amh and Cyp19a1a. Primers were designed to each gene, to enable confirmation of the gene sequences, by PCR and RACE-PCR. Using this approach, no confirmed sequence was obtained for Cyp19a1a, however sequences were obtained for part of the Vasa gene and a large part of the Amh gene, including the 3’end. 

The availability of these sex differentiation gene sequences allowed expression of Vasa, Amh and Cyp19a1a to be investigated. Primers were designed using the confirmed sequences for Vasa and Amh, as well as the unconfirmed sequence for Cyp19a1a. These were used in real-time PCR to examine the expression of each gene during development, within larvae at hatching, 3 days post hatch (dph), 12 dph and 18 dph. Expression of each gene was found to increase by 12 dph, but then decrease at 18dph, however, no meaningful significant difference in expression was seen statistically between any of the time points.

Lastly, a protocol was developed for embedding and sectioning of larvae from a range of different ages. A number of attempts were made to optimise an approach, with fish from 3 dph to 60 dph eventually being paraffin embedded, sectioned and stained with either toluidine blue or hematoxylin and eosin (H&E). A number of regions of interest were described, with one showing good similarity to early gonad formation, detailed in other studies. However, due to technical issues and time constraints, no PGCs or presumptive gonad tissues could be positively identified. Future work will use prepared sections to stain for the sex differentiation genes, to gain a better understanding of their role during development. 

This study has established a platform for further work on S. lalandi by creating a framework of molecular tools for studying sex differentiation genes and their expression in this species. It has also worked towards refining the histological techniques required to successfully analyse structural development in larvae. This will be valuable for future studies with techniques such as in-situ hybridisation, assisting in the development of tools for the improvement of S. lalandi aquaculture, for applications such as monosex culture and surrogate broodstock technology.

text: Molecular Characterisation of Sex Differentiation Genes in Yellowtail Kingfish (Seriola lalandi) Species diversification is crucial for the successful establishment and growth of a finfish aquaculture industry in New Zealand. The yellowtail kingfish Seriola lalandi is a promising candidate species with a fast growth rate, high market value, and is successfully farmed overseas, along with several other Seriola species. To truly domesticate any farmed species, understanding reproduction is vital. Sexual differentiation is a key part of early reproductive development and is characterised by the migration of primordial germ cells through the body to the site of the presumptive gonad, where they proliferate and differentiate into spermatogonia and oogonia. A number of key genes are expressed during sex differentiation, but currently very little molecular research has been conducted on S. lalandi. 

Using bioinformatics approaches, the available gene databases and the implementation of a transcriptomic library prepared from the gonad, ovary and pituitary tissue of S. lalandi, a number of key sex differentiation genes were identified, which included, Vasa, Amh and Cyp19a1a. Primers were designed to each gene, to enable confirmation of the gene sequences, by PCR and RACE-PCR. Using this approach, no confirmed sequence was obtained for Cyp19a1a, however sequences were obtained for part of the Vasa gene and a large part of the Amh gene, including the 3’end. 

The availability of these sex differentiation gene sequences allowed expression of Vasa, Amh and Cyp19a1a to be investigated. Primers were designed using the confirmed sequences for Vasa and Amh, as well as the unconfirmed sequence for Cyp19a1a. These were used in real-time PCR to examine the expression of each gene during development, within larvae at hatching, 3 days post hatch (dph), 12 dph and 18 dph. Expression of each gene was found to increase by 12 dph, but then decrease at 18dph, however, no meaningful significant difference in expression was seen statistically between any of the time points.

Lastly, a protocol was developed for embedding and sectioning of larvae from a range of different ages. A number of attempts were made to optimise an approach, with fish from 3 dph to 60 dph eventually being paraffin embedded, sectioned and stained with either toluidine blue or hematoxylin and eosin (H&E). A number of regions of interest were described, with one showing good similarity to early gonad formation, detailed in other studies. However, due to technical issues and time constraints, no PGCs or presumptive gonad tissues could be positively identified. Future work will use prepared sections to stain for the sex differentiation genes, to gain a better understanding of their role during development. 

This study has established a platform for further work on S. lalandi by creating a framework of molecular tools for studying sex differentiation genes and their expression in this species. It has also worked towards refining the histological techniques required to successfully analyse structural development in larvae. This will be valuable for future studies with techniques such as in-situ hybridisation, assisting in the development of tools for the improvement of S. lalandi aquaculture, for applications such as monosex culture and surrogate broodstock technology.

year: 2015

title: Influence of employee well-being on workplace injuries: A study of safety climate as a potential mediator

authors: Sim, Mabelene

subjects: Employee Well-Being

abstract: Being at work constitutes a considerable part of our lives and research on employee well-being and safety-related outcomes at the workplace can help to improve people’s work lives. This study examined the work-related employee well-being and individual workplace injuries relationship and how safety climate potentially mediates the association. The current research sets out to (1) examine the connection of employee well-being with workplace injuries, and the influence of safety climate on this relationship, and (2) assesses the level of employee well-being, safety climate and its association with injuries in a global city country in South East Asia, Singapore.
This study adopted a cross-sectional design utilising self-reported data from 147 participants aged 21 to 69 with work experience ranging from 6 months to 37 years across various industries within the manufacturing sector. Results of the current study illustrate that when employee well-being increases, safety climate also increases. In addition, when employee well-being and safety climate improves, individual workplace injury reduces. Among employee well-being and safety climate dimensions, having meaning and positive emotions at work and management’s attitude, behaviour and actions profoundly influence injuries in the workplace. Long working hours negatively affect safety climate and workplace injuries. Age and experience have a small to medium effect on injuries at the workplace, with employees aged between 45-49 years old and those with work experience between 16-25 years reporting more injuries. Management staff reported better employee well-being and lower injuries, while shift workers indicated weaker safety climate. Respondents also indicated that approximately 50% of workplace injuries were unreported, but when employees display appropriate behaviour in reporting workplace injuries, they experience higher employee well-being and safety climate. Mediation analysis indicated that safety climate did act as a mediator between employee well-being and workplace injuries. The mediation model including four control variables age, tenure, hierarchy and work hours, accounted for approximately 20% of the variance in individual injuries at the workplace.
Practically, utilising established employee well-being and safety climate construct, together with commonly available demographic variables, organisations can combat workplace injuries. Theoretically, this these findings from Singapore contribute to the literature of employee well-being from a positive psychology perspective and extend the safety climate literature in an Asian context. Moreover, this study suggests cross-cultural applicability for the relevant measures, having utilised a Hungarian employee well-being measure and a Norwegian safety climate instrument for an Asian sample. Overall, to tackle safety-related outcomes, employers must first take care of employee’s well-being at work and management-related factors towards safety perception.

text: Influence of employee well-being on workplace injuries: A study of safety climate as a potential mediator Being at work constitutes a considerable part of our lives and research on employee well-being and safety-related outcomes at the workplace can help to improve people’s work lives. This study examined the work-related employee well-being and individual workplace injuries relationship and how safety climate potentially mediates the association. The current research sets out to (1) examine the connection of employee well-being with workplace injuries, and the influence of safety climate on this relationship, and (2) assesses the level of employee well-being, safety climate and its association with injuries in a global city country in South East Asia, Singapore.
This study adopted a cross-sectional design utilising self-reported data from 147 participants aged 21 to 69 with work experience ranging from 6 months to 37 years across various industries within the manufacturing sector. Results of the current study illustrate that when employee well-being increases, safety climate also increases. In addition, when employee well-being and safety climate improves, individual workplace injury reduces. Among employee well-being and safety climate dimensions, having meaning and positive emotions at work and management’s attitude, behaviour and actions profoundly influence injuries in the workplace. Long working hours negatively affect safety climate and workplace injuries. Age and experience have a small to medium effect on injuries at the workplace, with employees aged between 45-49 years old and those with work experience between 16-25 years reporting more injuries. Management staff reported better employee well-being and lower injuries, while shift workers indicated weaker safety climate. Respondents also indicated that approximately 50% of workplace injuries were unreported, but when employees display appropriate behaviour in reporting workplace injuries, they experience higher employee well-being and safety climate. Mediation analysis indicated that safety climate did act as a mediator between employee well-being and workplace injuries. The mediation model including four control variables age, tenure, hierarchy and work hours, accounted for approximately 20% of the variance in individual injuries at the workplace.
Practically, utilising established employee well-being and safety climate construct, together with commonly available demographic variables, organisations can combat workplace injuries. Theoretically, this these findings from Singapore contribute to the literature of employee well-being from a positive psychology perspective and extend the safety climate literature in an Asian context. Moreover, this study suggests cross-cultural applicability for the relevant measures, having utilised a Hungarian employee well-being measure and a Norwegian safety climate instrument for an Asian sample. Overall, to tackle safety-related outcomes, employers must first take care of employee’s well-being at work and management-related factors towards safety perception.

year: 2019

title: Unorthodox assistance: Novalis, Māori, scientism, and an uncertain approach to 'Whakapapa'

authors: Mika, Carl Te Hira

abstract: The reductionism of Western science is well noted among several Maori academics, who describe in various ways its methodical tendency to dissemble an organism and isolate its parts. The reductionist nature of the method of science then informs the practice, so that the manifestations of science - its latest innovations, evidenced in biotechnology, cloning, stem cell therapy and so on - become an overriding concern for these academics. Rightly, the effects of those innovations on Maori spiritual and phYSical realms are addressed, to the extent that they may constitute extensive submissions to governmental bodies. How effective these submissions are is open to considerable speculation, particularly when it is acknowledged by many of these same writers that those ministerial and judicial bodies are incapable of understanding the dilemmas posed by the effects of reductionist scientific practice on the Maori world. The Maori world, in the main, is left to wait until it is confronted with yet another scientific advancement or technology, and the rush to counter its modus operandi begins again.

text: Unorthodox assistance: Novalis, Māori, scientism, and an uncertain approach to 'Whakapapa' The reductionism of Western science is well noted among several Maori academics, who describe in various ways its methodical tendency to dissemble an organism and isolate its parts. The reductionist nature of the method of science then informs the practice, so that the manifestations of science - its latest innovations, evidenced in biotechnology, cloning, stem cell therapy and so on - become an overriding concern for these academics. Rightly, the effects of those innovations on Maori spiritual and phYSical realms are addressed, to the extent that they may constitute extensive submissions to governmental bodies. How effective these submissions are is open to considerable speculation, particularly when it is acknowledged by many of these same writers that those ministerial and judicial bodies are incapable of understanding the dilemmas posed by the effects of reductionist scientific practice on the Maori world. The Maori world, in the main, is left to wait until it is confronted with yet another scientific advancement or technology, and the rush to counter its modus operandi begins again.

year: 2011