Expression and activity of critical digestive enzymes during early larval development of the veined rapa whelk, Rapana venosa (Valenciennes, 1846)

Symbiotic microbiome and metabolism profiles reveal the effects of induction by oysters on the metamorphosis of the carnivorous gastropod Rapana venosa

“…In this study, induction by juvenile oyster increased the expression of carboxypeptidase while slightly decreasing the expression of cellulase ( Fig. 1 ), which is consistent with the change in food habit transition during the metamorphosis of R. venosa [20] , [31] , [35] . Our results suggest that the digestive system of the R. venosa larvae responded to the induction by juvenile oysters and that digestive enzyme expression changed to meet the needs of food habit transition and metamorphosis, which is consistent with a previous study in grass carp showing that feeding plants to juvenile grass carp in advance can promote the development of its digestive system and change the activity of digestive enzymes [25] .…”

“…First-strand cDNA for qRT-PCR was synthesized using the Prime Script™ RT Reagent Kit with gDNA Eraser (TaKaRa, Japan). Primers for qRT-PCR were designed based on the full-length cDNA sequences of the carboxypeptidase, cellulase, 5-HT receptor, NOS and CCK receptor genes ( Table S1 ), which are dramatically shifted during metamorphosis in R. venosa [20] , [25] , [35] . The 60S ribosomal protein L28 (RL28-F, RL28-R) was used as a housekeeping gene for signal normalization within the experiment [36] .…”

“…In our previous studies, we found that the digestive system and the neuroendocrine system were dramatically changed during metamorphosis [20] , [21] . Critical digestive enzymes, such as carboxypeptidase and cellulase , were significantly changed during metamorphosis, which reflects the food habit transition in the metamorphosis of R. venosa .…”

Changes in Symbiotic Microbiota and Immune Responses in Early Development Stages of Rapana venosa (Valenciennes, 1846) Provide Insights Into Immune System Development in Gastropods

“…(Song et al, 2017a). SYBR PrimeScript TM RT-PCR Kit II (TaKaRa, Japan) was used with an Eppendorf Mastercycler R ep Realplex (Eppendorf, Hamburg, Germany) for qRT-PCR analysis following the manufacturer's protocols (Yang et al, 2020). Standard curves were made with 10-, 10 2 -, 10 3 -, 10 4 -, and 10 5 -fold dilutions of each cDNA template, and qRT-PCR was carried out with this program: 95 • C for 5 s and 40 cycles of 95 • C for 15 s, then 60 • C (Toll-like receptor 2, defensin) or 58 • C (tumor necrosis factor) for 30 s. The 2 − Ct method was used to analyzed the relative gene expression.…”

The Characteristic of Critical Genes in Neuroendocrine System and Their Regulation on Food Habit Transition and Metamorphosis of Veined Rapa Whelk Rapana venosa (Valenciennes, 1846)

“…Planktonic larval and postlarval samples were collected from five major developmental stages: the one-spiral whorl stage (V-I), the two-spiral whorl stage (V-II), the three-spiral whorl stage (V-III), the four-spiral whorl stage (competent larva, V-IV), and the postlarval stage (J). The samples were collected based on the methods described in our previous study (Yang et al, 2020a), and each developmental stage was sampled in triplicate and sextuplicate and stored at −80 • C for qRT-PCR, respectively, and each sample contains 30 larvae. For the immunohistochemistry (IHC) assays, larvae at different developmental stages were washed in PBS, and 7.5% MgCl2 solution was slowly added to completely anesthetize the larvae.…”