Induction of meiotic gynogenesis in bagrid catfish (Pseudobagrus ussuriensis) with homologous sperm and its confirmation for female homogamety

Abstract

The bagrid catfish, Pseudobagrus ussuriensis, exhibits significant sexual dimorphism in growth rate and body size with males growing faster than females. Therefore, an all‐male culture can dramatically increase the output and profitability of fishery products. According to the monosex breeding route, super‐male individuals’ acquirement by XY male sex reversal and artificial gynogenesis is the key step. An effective protocol to induce meiotic gynogenesis using homologous sperms has been developed in this study. The most effective UV irradiation for sperm genetic inactivation was found to be at a distance of 20 cm with 66 μW/cm2 light intensity for 25 min. Optimal treatment for cold shock was 5 min post‐fertilization at 0‐4°C for 30 min, which gave the best survival rate of 13.65 ± 2.87%. The sex ratio in the meiotic gynogens showed a significant female‐biased deviation (p < .05); thirty meiogynogens and their parents were further analysed using a male‐specific AFLP marker, of which only the male parent produced a male‐specific DNA band of 412 bp. These results indicated the female homogametic XX/XY sex determination system in P. ussuriensis. The optimization of a protocol for the successful induction of meiogynogenesis in the bagrid catfish lays the basis for all‐male production and is useful in ascertaining the genetic sex determination system in this promising aquaculture species.

Masculinization under combined administration of an androgen and an aromatase inhibitor in the Ussuri catfish,Pelteobagrus ussuriensis(Dybowski, 1872)

“…The experimental data for the three responses are presented in Table . According to Pan et al (), the sex determination mechanism for Ussuri catfish is represented as female homogamety and male heterogamety. The sex ratio for the untreated run (run 6, no MT and AI administered) should be male: female = 1:1.…”

“…Sex differentiation is completed at the age of 5 months in S. senegalensis , with females differentiating earlier than males (Viñas et al, ). According to Pan et al (), sex differentiation in the Ussuri catfish starts at 21 dph. In our study, MT and the AI were administered at 15 dph.…”

Meiotic gynogenesis with heterologous sperm in the mandarin fish Siniperca chuatsi and evidence for female homogamety

“…Although morphology examination has strongly suggested that all adult gynogens inherited from the maternal genome of S. chuatsi with no contribution of the paternal genome from S. scherzeri in this study, further evidence may be needed to exclusively clarify the parentage in the meiotic gynogenesis of mandarin fish. Microsatellite markers have greatly facilitated molecular identification of the gynogenetic offspring in fish, because of their PCR‐based, co‐dominant Mendelian inheritance pattern and highly polymorphic characteristics (Chistiakov, Hellemans, & Volckaert, ; Pan et al, ). Exclusive maternal inheritances have been confirmed in meiotic gynogenetic large‐scale loach (You et al, ), grass carp (Zhang et al, ) and tongue sole (Ji et al, ) by microsatellite makers.…”

“…Fertilization rates and hatching rates of the experiment groups of gynogenesis seem of no apparent difference with those of the haploid control group, indicating that spotted mandarin fish is a suitable donor of irradiated heterologous sperm. Mendelian inheritance pattern and highly polymorphic characteristics (Chistiakov, Hellemans, & Volckaert, 2006;Pan et al, 2017).…”

“…By recording sex ratios of successfully induced gynogens, sex determination types have been proposed to be XX/XY in some fish, for example, Mozambique tilapia (Oreochromis mossambicus) (Campos-Ramos, Harvey, Mcandrew, & Penman, 2003), large yellow croaker (Pseudosciaena crocea) (Xu, You, Yan, & Zhang, 2007) and bagrid catfish (Pseudobagrus ussuriensis) (Pan et al, 2017). While in large-scale loach (Paramisgurnus dabryanus) (You, Yu, Tan, & Tong, 2008), half-smooth tongue sole (Cynoglossus semilaevis) (Chen et al, 2009) and turbot (Scophthalmus maximus) (Meng et al, 2016), a mode of ZZ/ZW was believed to be their sex determination types.…”