The growth,energy allocation,and body composition of the brown flounder(Paralichthys olivaceus)during the cycles of high temperature-optimal temperature operation

2011 ◽  
Vol 34 (8) ◽  
pp. 1236-1243 ◽  
Author(s):  
Jie LI ◽  
Guo-qiang HUANG ◽  
Xiu-mei ZHANG ◽  
Liu-zhi WEI ◽  
Xia TANG
Keyword(s):  
Body Composition ◽  
High Temperature ◽  
Paralichthys Olivaceus ◽  
Energy Allocation ◽  
Optimal Temperature ◽  
Growth Energy

scholarly journals High temperatures during microsporogenesis fatally shorten pollen lifespan

2021 ◽  
Author(s):  
Maurizio Iovane ◽  
Giovanna Aronne
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Heat Stress ◽  
High Temperature ◽  
Male Gametophyte ◽  
Crop Productivity ◽  
Anther Dehiscence ◽  
Optimal Temperature ◽  
Drastic Reduction ◽  
Crop Species

AbstractMany crop species are cultivated to produce seeds and/or fruits and therefore need reproductive success to occur. Previous studies proved that high temperature on mature pollen at anther dehiscence reduce viability and germinability therefore decreasing crop productivity. We hypothesized that high temperature might affect pollen functionality even if the heat treatment is exerted only during the microsporogenesis. Experimental data on Solanum lycopersicum ‘Micro-Tom’ confirmed our hypothesis. Microsporogenesis successfully occurred at both high (30 °C) and optimal (22 °C) temperature. After the anthesis, viability and germinability of the pollen developed at optimal temperature gradually decreased and the reduction was slightly higher when pollen was incubated at 30 °C. Conversely, temperature effect was eagerly enhanced in pollen developed at high temperature. In this case, a drastic reduction of viability and a drop-off to zero of germinability occurred not only when pollen was incubated at 30 °C but also at 22 °C. Further ontogenetic analyses disclosed that high temperature significantly speeded-up the microsporogenesis and the early microgametogenesis (from vacuolated stage to bi-cellular pollen); therefore, gametophytes result already senescent at flower anthesis. Our work contributes to unravel the effects of heat stress on pollen revealing that high temperature conditions during microsporogenesis prime a fatal shortening of the male gametophyte lifespan.

Roles of forkhead box protein L2 (foxl2) during gonad differentiation and maintenance in a fish, the olive flounder (Paralichthys olivaceus)

2019 ◽  
Vol 31 (11) ◽  
pp. 1742 ◽  
Author(s):  
Zhaofei Fan ◽  
Yuxia Zou ◽  
Dongdong Liang ◽  
Xungang Tan ◽  
Shuang Jiao ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cytochrome P450 ◽  
High Temperature ◽  
Paralichthys Olivaceus ◽  
Sex Reversal ◽  
Olive Flounder ◽  
Gonad Differentiation ◽  
Forkhead Box ◽  
Cytochrome P450 Family ◽  
Olive Flounder Paralichthys Olivaceus

As an important maricultured fish, the olive flounder Paralichthys olivaceus shows sex-dimorphic growth. Thus, the molecular mechanisms involved in sex control in P. olivaceus have attracted researchers’ attention. Among the sex-related genes, forkhead box protein L2 (foxl2) exhibits significant sex-dimorphic expression patterns and plays an important role in fish gonad differentiation and development. The present study first investigated the expression levels and promoter methylation dynamics of foxl2 during flounder gonad differentiation under treatments of high temperature and exogenous 17β-oestradiol (E2). During high temperature treatment, the expression of flounder foxl2 may be repressed via maintenance of DNA methylation. Then, flounder with differentiated testis at Stages I–II were treated with exogenous 5ppm E2 or 5ppm E2+150ppm trilostane (TR) to investigate whether exogenous sex hormones could induce flounder sex reversal. The differentiated testis exhibited phenotypic variations of gonadal dysgenesis with upregulation of female-related genes (foxl2 and cytochrome P450 family 19 subfamily A (cyp19a)) and downregulation of male-related genes (cytochrome P450 family 11 subfamily B member 2 (cyp11b2), doublesex- and mab-3 related transcription factor 1 (dmrt1), anti-Mullerian hormone (amh) and SRY-box transcription factor 9 (sox9)). Furthermore, a cotransfection assay of the cells of the flounder Sertoli cell line indicated that Foxl2 was able alone or with nuclear receptor subfamily 5 group A member 2 (Nr5a2) jointly to upregulate expression of cyp19a. Moreover, Foxl2 and Nr5a2 repressed the expression of dmrt1. In summary, Foxl2 may play an important role in ovarian differentiation by maintaining cyp19a expression and antagonising the expression of dmrt1. However, upregulation of foxl2 is not sufficient to induce the sex reversal of differentiated testis.

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