- 著者
- Akira Ishikawa Yuta Takei Ken-Ichiro Ishii Mineo Yamaguchi
- 出版者
- The Plankton Society of Japan, The Japanese Association of Benthology
- 雑誌
- Plankton and Benthos Research (ISSN:18808247)
- 巻号頁・発行日
- vol.17, no.4, pp.383-392, 2022-11-30 (Released:2022-11-30)
- 参考文献数
- 46
The temporal changes in the behavior of vegetative cells and cysts of the noxious red tide flagellates Chattonella (C. antiqua and C. marina) were investigated in Ago Bay, central Japan, mainly in 2013. In this study, in situ germination flux (cells m−2 day−1) was measured in May, June, and October 2013, using a ‘plankton emergence trap/chamber (PET chamber)’. Vegetative cells occurred in April and increased from May, forming a bloom in July with cyst production, and subsequently decreased thereafter. This change in the occurrence of the vegetative cells was considered to be controlled primarily by temperature and secondarily by nutrients and biotic factors. The PET chamber experiment showed that cyst germination in May contributed largely to forming the initial vegetative population to initiate blooming. An experiment to elucidate the effect of storage temperature on the germinability of cysts in the sediment showed that newly produced cysts (immature dormant cysts) mature (acquire germinability) under low storage temperature (10°C) within at least one month, indicating that cysts need to experience a cold season in the sediment for their maturation. The PET chamber experiment conducted in October before a cold season also confirmed that cysts scarcely germinated from the cyst population, containing many immature dormant cysts, in the in situ sediment. However, these cysts could act as seeds to form the initial population of the subsequent bloom in the next season, since the cysts will mature by then. Consequently, Chattonella cysts were concluded to play crucial roles in the population dynamics.
- 著者
- Sae Suzuki Misato Kobayashi Atsushi Murai Masaoki Tsudzuki Akira Ishikawa
- 出版者
- Japan Poultry Science Association
- 雑誌
- The Journal of Poultry Science (ISSN:13467395)
- 巻号頁・発行日
- vol.56, no.2, pp.101-111, 2019 (Released:2019-04-25)
- 参考文献数
- 31
- 被引用文献数
- 14
Excessive fat deposition adversely affects poultry production. In this study, we investigated growth, fat deposition, and hepatic mRNA expression of 13 lipid metabolism-related genes in three unique breeds of meat-type chickens with distinct breed origins and genetic relationships. One was Nagoya (NAG), a native Japanese breed, whereas the others were White Plymouth Rock (WPR) and White Cornish (WC), which have been used worldwide as the parental breeds of common broiler chickens. NAG chickens were phenotypically characterized by slow growth, lean body fat, and high gizzard and liver weights. In contrast, both WC and WPR chickens were characterized by rapid growth but high percentage of subcutaneous fat and abdominal fat weight, resulting from high feed intake. Among the three breeds, WC had the highest percentage of pectoral muscle weight, whereas WPR was the most obese. Among lipid metabolism-related genes, the expression of PPARA, PPARG, and CD36 was mostly associated with obesity. These results provide basic information for quantitative trait locus (QTL) analysis related to growth and fat traits in an F2 population of the lean NAG breed and the obese WPR breed of meat-type chickens in future.