Aquaculture America 2021

August 11 - 14, 2021

San Antonio, Texas

Add To Calendar 14/08/2021 09:30:0014/08/2021 09:50:00America/ChicagoAquaculture America 2021EFFECT OF SEASONALITY FOR OPTIMIZATION OF STEM CELL EXTRACTION FROM MATURE BLUE CATFISH Ictalurus furcatus TO PRODUCE ALLOXENOGENIC CATFISHRoom 3The World Aquaculture Societyjohnc@was.orgfalseanrl65yqlzh3g1q0dme13067DD/MM/YYYY

EFFECT OF SEASONALITY FOR OPTIMIZATION OF STEM CELL EXTRACTION FROM MATURE BLUE CATFISH Ictalurus furcatus TO PRODUCE ALLOXENOGENIC CATFISH

Darshika U. Hettiarachchi*., Veronica Alston., Jeremy Gurbatow., Vahid Zadmajid., Andrew Johnson., Jinhai Wang., Michael P Coogan., De Xing., Shangjia Li., Ian A.E. Butts., Rex A. Dunham.
 
School of Fisheries, Aquaculture and Aquatic Sciences
Auburn University
Alabama, USA 36849.
E-mail address; duh0001@auburn.edu
 

Xenogenesis is an innovative tool for hybrid catfish (♀ channel catfish, Ictalurus punctatus × ♂ blue catfish, I. furcatus) seed production. The xenogeneic process can be accomplished by transplanting diploid primordial germ cells (PGCs), spermatogonial stem cells (SSCs) or oogonial stem cells (OSCs), derived from a donor diploid fish into a sterile recipient, which then enables recipient fish to produce donor-derived gametes. Usually, stem cells are collected from immature fish. However, there is a potential to collect donor-derived cells from mature fish during certain times of the year depending upon seasonal temperature fluctuations. Therefore, the current study was carried out with the objective of evaluating seasonal variations in germ cell count and sex steroid hormone profiles in mature blue catfish. Mature males and females (weight >1 kg and total length >50 cm) were sampled each month for an entire year. At each time sampling, gonadal weight (± 0.05 g), gonado-somatic index (GSI), and stem cell counts, including total number of live and dead SSCs and total number of live and dead OSCs in fish were determined. In addition, a blood (~1 mL) sample was collected from each fish to quantify the level of sex steroid hormones, testosterone (T), 11-ketotestosterone (11-KT), and 17β-estradiol using ELISA.

The highest quantity of live type A SSCs (P < 0.0001) in male blue catfish was recorded in April (7.053 × 104 cells), which then gradually decreased until November, where the lowest production was reported (0.19 ×104 cells). Mean GSI of blue catfish males ranged from 0.067% to 0.318%, which was significantly higher in November to March compared to levels reported in July to September. The highest quantity of live OSCs (P < 0.0001) in female blue catfish was observed in April (9.6 × 102 cells), which gradually decreased to zero over the months of May to July. No OSCs were observed during the months of August to February, as ovaries were full of immature oocytes. GSI levels of females remained consistent in the range of 11.3% - 6.7% from April to March, which showed no significant differences over time. Hormonal analyses are in progress and results will be presented.

In conclusion, we confirm the efficacy of using mature blue catfish males as donor species during the months of April, May, and June, which will be an added advantage during the xenogeneic process. However, it is less effective to use mature blue catfish females as donors due to their low OSC counts.