Thongda Willawan, Chung J Sook, Tsutsui Naoaki, Zmora Nilli, Katenta Anna
Institute of Marine and Environmental Technology, 701 East Pratt Street, Columbus Center, Baltimore, MD 21202, USA.
Institute of Marine and Environmental Technology, 701 East Pratt Street, Columbus Center, Baltimore, MD 21202, USA.
Comp Biochem Physiol A Mol Integr Physiol. 2015 Jan;179:35-43. doi: 10.1016/j.cbpa.2014.08.019. Epub 2014 Sep 16.
In general, season affects the physiology and behavior of most animals. Warmer temperatures accelerate growth and reproduction of ectotherms, whereas these processes are slowed or halted in colder temperatures. Female blue crabs, Callinectes sapidus inhabiting the Chesapeake Bay, exhibit a seasonal migratory behavior that is closely tied with spawning and the release of larvae. To better understand reproductive activities of the migratory adult females, we examined two reproductive parameters of these crabs sampled monthly (April-December, 2006): the levels of vitellogenin (VtG) in the hemolymph and VtG expression in the hepatopancreas and ovary. The full-length cDNA of VtG (CasVtG-ova) has been isolated from the ovary. The putative CasVtG sequence found in the ovary is >99% identical to that of the hepatopancreas and is related most closely to the sequences reported in other crab species. In female C. sapidus, the hepatopancreas produces over 99% of the total VtG toward the ovarian development. Ovarian stages 2 and 3 in the sampled females are characterized by significant high levels of VtG in hemolymph and VtG expression in both the hepatopancreas and ovary. However, during the southbound migration in fall, females at ovarian stages 2 and 3 have decreased VtG levels, compared to those in spring and summer. The decreased vitellogenesis activity during the fall migration suggests seasonal adaptation to ensure successful spawning and the larval release.
一般来说，季节会影响大多数动物的生理和行为。温度升高会加速变温动物的生长和繁殖，而在较低温度下这些过程会减缓或停止。栖息在切萨皮克湾的雌性蓝蟹（Callinectes sapidus）表现出一种季节性洄游行为，这种行为与产卵和幼体释放密切相关。为了更好地了解洄游成年雌性蓝蟹的繁殖活动，我们研究了这些每月（2006年4月至12月）采样的蓝蟹的两个繁殖参数：血淋巴中的卵黄蛋白原（VtG）水平以及肝胰腺和卵巢中的VtG表达。VtG的全长cDNA（CasVtG-ova）已从卵巢中分离出来。在卵巢中发现的推定CasVtG序列与肝胰腺中的序列相似度超过99%，并且与其他蟹类物种报道的序列关系最为密切。在雌性蓝蟹中，肝胰腺产生的VtG占卵巢发育所需总量的99%以上。采样雌性蓝蟹的卵巢2期和3期的特征是血淋巴中VtG水平显著升高，肝胰腺和卵巢中VtG表达也显著升高。然而，在秋季向南洄游期间，卵巢2期和3期的雌性蓝蟹的VtG水平与春季和夏季相比有所下降。秋季洄游期间卵黄生成活动的下降表明存在季节性适应，以确保成功产卵和幼体释放。
