This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.

Cinnamon clownfish, Amphiprion melanopus, typically live as part of a mated adult pair or an adult pair and an immature individual and social ranking in the group controls the sexes of the fish. In general, the female is the larger and dominant individual. If a dominant female dies or is absent, the male partner undergoes a sex change to become a female. This special reproductive characteristic provides a good model for which to study the mechanism of sex change. Sexual development and gonadal maturation in fish are regulated by hormones of the hypothalamus-pituitary-gonad (HPG) axis including gonadotropin-releasing hormone (GnRH) and other neurohormones, gonadotropins, and gonadal steroid hormones and peptides. Specially, light is among the most important natural environmental factors that regulate reproduction in fish. Light-emitting diodes (LEDs), which is a new form of lighting technology can be designed to output specific wavelengths such as narrow bandwidth light which is important because it can be tuned to the environmental sensitivity of a target species. In the experiment, the white fluorescent bulb and different LED (red, peak at 630 nm; green, 530 nm) were used. The effects of different illuminations were assessed by measuring the mRNA and protein expressions of HPG axis genes and sex steroid hormone level. For green LED light, significantly higher levels of HPG axis genes expressions, GSI, and plasma sex steroid hormone were obtained, compared to the red LED light spectra. Histological analysis also revealed the presence of vitellogenic oocytes in fish exposed to green LED light. The results indicate that exposure to short wavelength lighting accelerates gonadal maturation and sex change, and is likely to facilitate development of more energy-efficient aquaculture procedures. Also, have investigated that light reaction in marine organism's mechanism using LED lights, and high potential of application of Bio-photonics for the aquaculture.

내분비계 장애물질은 다양한 동물의 생식과 배아의 발생에 위해한 영향을 미친다고 보고되었다. 이러한 초기 배아의 비정상 발생 중 대표적인 것이 할구파편이다. 본 연구에서는 착상 전 생쥐 초기 배아를 PCB, BPA, DDT에 체내, 체외에서 각각 노출시켰다. 내분비계 장애 물질에 노출시켰던 배아는 할구파편, 불규칙한 할구와 깨짐, 일부 파괴된 투명대 배아 등의 다양한 형태학적 비정상 양상을 보였다. 착상 전 생쥐 초기배아의 세포괴사에 관여하는 유전자를 조