Induced Gynogenesis in Grass Carp (Ctenopharyngodon idellus) Using Irradiated Sperm of Allotetraploid Hybrids

Abstract

Grass carp (Ctenopharyngodon idellus) eggs were activated by UV-irradiated diploid sperm of allotetraploid hybrids derived from red crucian carp (♀) × common carp (♂) and then duplicated by cold shock in 4-6°C water for 10-12 min. Different cold shock initiation times resulted in two types of diploid gynogenetic grass carp: meiotic gynogenetic (meiG) and mitotic gynogenetic (mitG). Over a 5-year period, a total of 17,170 meiG and 1,080 mitG fry were produced and 6,862 meiG and 372 mitG grass carp survived. The gynogenetic fish were confirmed by morphological characteristics, chromosome examination, and microsatellite DNA analysis. The morphological traits of the gynogenetic grass carp were similar to those of wild diploid grass carp. Normal gynogenetic fish were identified as diploid with 48 chromosomes by chromosomal metaphases examination, while nonviable abnormal embryos were detected as haploid with 24 chromosomes. Microsatellite DNA analysis indicated that after one generation of gynogenesis, the genetic purity of meiG and mitG grass carp was significantly increased over that of wild grass carp. In addition, both meiG and mitG grass carp groups were 100% female, and 88% of these showed normal ovary development. Thus, the sex determination mechanism in female grass carp was homogamety. The ability to establish pure all-female groups of meiG and mitG grass carp should be a valuable contribution to both fish genetics and grass carp breeding.

Development and application of biological technologies in fish genetic breeding

“…The combination of artificial gynogenesis and sex reversal technology sets the stages for the production of all-female diploids and triploids [103,104]. It is worth noting that Zhang et al [105] have built disease-resistant gynogenetic strains of grass carp by the activation of inactivated sperm of tetraploids. These gynogenetic grass carp demonstrate that gynogenesis can be used to obtain all-female individuals that have desirable genetic traits.…”

“…Our group has developed gynogenetic strains from natural origin red crucian carp, Carassius auratus cuvieri, goldfish, common carp, orange ornamental carp (Cyprinus carpio), grass carp, Erythroculter ilishaeformis, Xenocypris davidi Bleeker, and artificially cultivated strains including tetraploid hybrids of common carp with red crucian carp and tetraploid hybrids of red crucian carp with blunt snout bream [103][104][105][106][107]. We have developed gynogenetic strains of red crucian carp, Japanese crucian carp, and goldfish following activation using heterogenous sperms (M. amblycephala).…”

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

“…Exclusive maternal inheritances have been confirmed in meiotic gynogenetic large-scale loach (You et al, 2008), grass carp (Zhang et al, 2011) and tongue sole (Ji et al, 2010) by microsatellite makers. For further confirming the gynogens of S. chuatsi in genomic level, seven microsatellite makers were amplified in this study.…”

“…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. For further confirming the gynogens of S. chuatsi in genomic level, seven microsatellite makers were amplified in this study.…”

“…In most fish, sex determination of fish is generally characterized by genetic models of either female homogamety (XX) and male heterogamety (XY) or male homogamety (ZZ) and female heterogamety (ZW) (Mei & Gui, ; Meng et al, ). If the sex ratio of the meiotic gynogens in one species was 100% or almost 100% females, it is suggested that an XX/XY sex determination type may operate in this species (Chourrout & Quillet, ; Rougeot, Ngingo, Gillet, Vanderplasschen, & Mélard, ; Zhang et al, ). Otherwise, a high proportion of males detected in diploid gynogens strongly suggests that the sex determination type of this species may be ZW/ZZ (Chen et al, ; Omoto, Maebayashi, Adachi, Arai, & Yamauchi, ; You et al, ).…”