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In vertebrates, sperm development and maturation are directly regulated by gonadal steroid hormone secretion. The relationships among the expression of genes encoding steroidogenic proteins and receptors for gonadotropins, and testicular steroid production have not yet been comprehensively determined in male teleosts. In this study, the changes in levels of mRNAs encoding follicle-stimulating hormone (FSH) receptor, luteinizing hormone (LH) receptor, steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage, 3 -hydroxysteroid dehydrogenase/n5-4-isomerase, cytochrome P450 17 -hydroxylase/17,20-lyase, cytochrome P450 11 -hydroxylase, 11 -hydroxysteroid dehydrogenase and 20 -hydroxysteroid dehydrogenase were determined by real-time, quantitative PCR assays and related to changes in serum steroid levels throughout the reproductive cycle in male rainbow trout. Serum 11-ketotestosterone and 17 ,20 -dihydroxy-4-pregnen-3-one levels were measured by RIA. Although the pattern of change in the mRNA levels for the enzymes was variable, the increases in steroidogenic enzyme mRNAs started prior to a significant increase of serum steroid levels. The patterns of transcript levels of FSH and LH receptors suggest that changes in StAR and steroidogenic enzyme transcripts are largely mediated by the FSH receptor during early and mid-spermatogenesis and by the LH receptor during late spermatogenesis and spermiation. Levels of StAR (10-fold) and P450 17 -hydroxylase/ 17,20-lyase (sevenfold) transcripts changed with the greatest magnitude and were closely related to the changes in serum steroids, suggesting that changes in StAR and P450 17 -hydroxylase/17,20-lyase abundance are likely to be the major influences on overall steroidogenic output during the reproductive cycle in male rainbow trout.

Online learning has become a ubiquitous part of the educational landscape and how teachers are supported in developing approaches to teaching online is a fundamental aspect of the students' learning experience. Based on the implementation of a professional development course on becoming an online teacher offered in a blended learning mode at one university in Hong Kong, this article proposes that offering this type of professional development in a blended mode is very effective in facilitating enhanced usage of the university's learning management system. In a blended mode, teachers are actively engaged with blended learning and were found to make more extensive use of features/ tools in Blackboard after they attended the professional development course. Results support that offering professional development in a blended mode provides teachers with an authentic student perspective, at the same time as they take guided steps in the teacher's role in blended learning.

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