Embryonic and genetic manipulation in fish

Abstract

Fishes, the biggest and most diverse community in vertebrates are good experimental models for studies of cell and developmental biology by many favorable characteristics. Nuclear transplantation in fish has been thoroughly studied in China since 1960s. Fish nuclei of embryonic cells from different genera were transplanted into enucleated eggs generating nucleo-cytoplasmic hybrids of adults. Most importantly, nuclei of cultured goldfish kidney cells had been reprogrammed in enucleated eggs to support embryogenesis and ontogenesis of a fertile fish. This was the first case of cloned fish with somatic cells. Based on the technique of microinjection, recombinant MThGH gene has been transferred into fish eggs and the first batch of transgenic fish were produced in 1984. The behavior of foreign gene was characterized and the onset of the foreign gene replication occurred between the blastula to gastrula stages and random integration mainly occurred at later stages of embryogenesis. This eventually led to the transgenic mosaicism. The MThGHtransferred common carp enhanced growth rate by 2-4 times in the founder juveniles and doubled the body weight in the adults. The transgenic common carp were more efficient in utilizing dietary protein than the controls. An all-fish gene construct CAgcGH has been made by splicing the common carp -actin gene (CA) promoter onto the grass carp growth hormone gene (gcGH)

Characterization of transgene integration pattern in F4 hGH-transgenic common carp (Cyprinus carpio L.)

“…The integration, expression and germline transmission of transgenes is the prerequisite of animal transgenesis [3]. In fish embryos, since the novel gene is commonly injected into the egg cytoplasm and the early embryonic cell cleavage is fairly rapid, the integration of foreign gene occurs during embryogenesis, resulting in transgenic mosaics [4,5]. The germline transmission of transgenes in fish has been described by different authors [6][7][8][9].…”

Identification of differential transcript profiles between mutual crossbred embryos of zebrafish (Danio rerio) and Chinese rare minnow (Gobiocypris rarus) by cDNA-AFLP

“…In the past few decades, substantial efforts have been undertaken to understand the interaction between nucleus and cytoplasm in fish, with the majority of studies performed using NT embryos [6,[18][19][20][21]. In the present study, a relatively innovative system anchored on crossbred embryos of zebrafish and Chinese rare minnow was utilized to address this question, since RZ embryos could be safely considered as the cross-species NT embryos derived from ZR nuclei and Chinese rare minnow egg cytoplasm.…”

Identification of a novel gene K23 over-expressed in fish cross-subfamily cloned embryos

“…Cross-species NT in fish has been successfully manipulated for over 40 years [10]. Recently, cross-genus cloned fish derived from common carp nuclei and goldfish enucleated eggs was given birth [11].…”