title: Pituitary mRNA expression of FSH and LH in yellowbelly flounder (Rhombosolea leporina)

authors: Curtis, Robert

subjects: yellowbelly flounder

abstract: Recent interest has been expressed in cultivating the native, yellowbelly flounder (Rhombosolea leporina). This is largely due to its high market and cultural value. Currently, there is little research on this species, both in an aquaculture setting and from an ecological perspective. This study focused on assessing pituitary mRNA expression of two gonadotropin-beta subunit genes, follicle-stimulating hormone (fshβ) and luteinising hormone (lhβ), in wild-caught yellowbelly flounder, to better understand captive reproduction for aquaculture.

The first study characterised the expression of both pituitary fshβ and lhβ in wild-caught yellowbelly flounder in different stages of ovarian development: 1) previtellogenic (PVO), 2) early vitellogenic (EVit), 3) vitellogenic (VIT), and 4) final oocyte maturation (FOM). Both genes showed significant increases in expression between stages 1 and 4. The expression patterns of both pituitary fshβ and lhβ were similar, with a trend of increasing levels across all ovarian stages to peak at stage 4. However, peak expression levels were much greater in fshβ. This is unexpected compared to typical fish models, where pituitary lhβ expression is often many-fold greater than fshβ during oocyte maturation. The reason for this apparent anomaly in peak expression levels is unknown. However, the general profile of increasing levels of co-expressed pituitary fshβ and lhβ throughout oogenesis likely reflects the multiple-batch group synchronous ovarian development found in yellowbelly flounder.

The second study focused on quantifying fshβ and lhβ expression over a five-day period following the injection of gonadotropin-releasing hormone analogue (GnRHa). Each female yellowbelly flounder was assigned to one of four treatment groups: 25 μg/kg, 50 μg/kg, 100 μg/kg, or a control group (0 μg/kg). Although there were no statistically significant increases in fshβ or lhβ expression from day 1 to day 5, an upward trend in both lhβ and fshβ expression was observed in fish treated with 25 μg/kg of GnRHa. Similarly, an increasing trend in lhβ expression was observed in fish treated with 50 μg/kg of GnRHa. GnRHa-treated fish accounted for the highest number of individuals entering FOM, comprising 87% of all fish that reached this stage. Additionally, 85% of all fish treated with GnRHa progressed to early maturation (EM) or further. Interestingly, the 100 μg/kg GnRHa treatment resulted in a downward trend of both fshβ and lhβ expression on both days 1 and 5 post-treatment. Despite this, the 100 μg/kg GnRHa treatment exhibited the joint-highest proportion of oocytes reaching maturity (33.3%) and had 90% of individuals reaching the early migratory (EM) stage or beyond. However, none of the fish were observed to ovulate over the 5-day experimental period.

text: Pituitary mRNA expression of FSH and LH in yellowbelly flounder (Rhombosolea leporina) Recent interest has been expressed in cultivating the native, yellowbelly flounder (Rhombosolea leporina). This is largely due to its high market and cultural value. Currently, there is little research on this species, both in an aquaculture setting and from an ecological perspective. This study focused on assessing pituitary mRNA expression of two gonadotropin-beta subunit genes, follicle-stimulating hormone (fshβ) and luteinising hormone (lhβ), in wild-caught yellowbelly flounder, to better understand captive reproduction for aquaculture.

The first study characterised the expression of both pituitary fshβ and lhβ in wild-caught yellowbelly flounder in different stages of ovarian development: 1) previtellogenic (PVO), 2) early vitellogenic (EVit), 3) vitellogenic (VIT), and 4) final oocyte maturation (FOM). Both genes showed significant increases in expression between stages 1 and 4. The expression patterns of both pituitary fshβ and lhβ were similar, with a trend of increasing levels across all ovarian stages to peak at stage 4. However, peak expression levels were much greater in fshβ. This is unexpected compared to typical fish models, where pituitary lhβ expression is often many-fold greater than fshβ during oocyte maturation. The reason for this apparent anomaly in peak expression levels is unknown. However, the general profile of increasing levels of co-expressed pituitary fshβ and lhβ throughout oogenesis likely reflects the multiple-batch group synchronous ovarian development found in yellowbelly flounder.

The second study focused on quantifying fshβ and lhβ expression over a five-day period following the injection of gonadotropin-releasing hormone analogue (GnRHa). Each female yellowbelly flounder was assigned to one of four treatment groups: 25 μg/kg, 50 μg/kg, 100 μg/kg, or a control group (0 μg/kg). Although there were no statistically significant increases in fshβ or lhβ expression from day 1 to day 5, an upward trend in both lhβ and fshβ expression was observed in fish treated with 25 μg/kg of GnRHa. Similarly, an increasing trend in lhβ expression was observed in fish treated with 50 μg/kg of GnRHa. GnRHa-treated fish accounted for the highest number of individuals entering FOM, comprising 87% of all fish that reached this stage. Additionally, 85% of all fish treated with GnRHa progressed to early maturation (EM) or further. Interestingly, the 100 μg/kg GnRHa treatment resulted in a downward trend of both fshβ and lhβ expression on both days 1 and 5 post-treatment. Despite this, the 100 μg/kg GnRHa treatment exhibited the joint-highest proportion of oocytes reaching maturity (33.3%) and had 90% of individuals reaching the early migratory (EM) stage or beyond. However, none of the fish were observed to ovulate over the 5-day experimental period.

year: 2025

title: Economical genotyping of little blue penguin (Eudyptula minor) clades from feather-based DNA

authors: Clark, Alan J.

subjects: Clades

abstract: Determination of clade membership is a crucial requirement for many research questions addressing phylogeography, population structure, mating patterns, speciation, and hybridisation. The little blue penguin (Eudyptula minor) can be separated into two deeply divergent clades. However, assigning clade membership in little blue penguins requires molecular methods. Genetic sequencing can be used to identify clade membership but is expensive. Here, we present an economical alternative to the use of sequencing to determine little blue penguin clade membership. We extracted DNA from feathers using a method that produced reasonable quantities of DNA. We then amplified the D-loop section of the mitochondrial control region from total genomic DNA extracts, using the primers 'C L-tRNAglu' and 'D H-Dbox' followed by digestion with the restriction enzyme AluI. When visualised on a gel, distinctive banding patterns clearly indicated clade membership. We sequenced a subset of our samples and verified the accuracy of this method. The methods we present should facilitate little blue penguin research through a cost-effective approach to clade analysis as well as a successful technique to extract DNA from feathers when blood or tissue samples are not available.

text: Economical genotyping of little blue penguin (Eudyptula minor) clades from feather-based DNA Determination of clade membership is a crucial requirement for many research questions addressing phylogeography, population structure, mating patterns, speciation, and hybridisation. The little blue penguin (Eudyptula minor) can be separated into two deeply divergent clades. However, assigning clade membership in little blue penguins requires molecular methods. Genetic sequencing can be used to identify clade membership but is expensive. Here, we present an economical alternative to the use of sequencing to determine little blue penguin clade membership. We extracted DNA from feathers using a method that produced reasonable quantities of DNA. We then amplified the D-loop section of the mitochondrial control region from total genomic DNA extracts, using the primers 'C L-tRNAglu' and 'D H-Dbox' followed by digestion with the restriction enzyme AluI. When visualised on a gel, distinctive banding patterns clearly indicated clade membership. We sequenced a subset of our samples and verified the accuracy of this method. The methods we present should facilitate little blue penguin research through a cost-effective approach to clade analysis as well as a successful technique to extract DNA from feathers when blood or tissue samples are not available.

year: 2013

title: An evaluation of Te Rau Puawai workforce 100: Evaluation overview

authors: Nikora, Linda Waimarie

subjects: Maori students

abstract: In July 2001, the Maori & Psychology Research Unit of the University of Waikato was asked to conduct an evaluation of the Te Rau Puawai programme, a joint venture between the former Health Funding Authority and Massey University. The overall goal of the programme is to contribute at least 100 Maori graduates to the Maori mental health workforce within a five year period. The overall aim of the evaluation was to provide the Ministry of Health with a clearer understanding of the programme including: the perceived critical success factors, the barriers if any regarding Te Rau Puawai, the impact of the programme, the extent to which the programme may be transferable, gaps in the programme, and suggested improvements. Through archival search, questionnaire surveys and interviews, evaluative data was collected from major stakeholders in the Te Rau Puawai programme.

text: An evaluation of Te Rau Puawai workforce 100: Evaluation overview In July 2001, the Maori & Psychology Research Unit of the University of Waikato was asked to conduct an evaluation of the Te Rau Puawai programme, a joint venture between the former Health Funding Authority and Massey University. The overall goal of the programme is to contribute at least 100 Maori graduates to the Maori mental health workforce within a five year period. The overall aim of the evaluation was to provide the Ministry of Health with a clearer understanding of the programme including: the perceived critical success factors, the barriers if any regarding Te Rau Puawai, the impact of the programme, the extent to which the programme may be transferable, gaps in the programme, and suggested improvements. Through archival search, questionnaire surveys and interviews, evaluative data was collected from major stakeholders in the Te Rau Puawai programme.

year: 2002-05-01