Viability, growth and external morphology of meiotic- and mitotic-gynogenetic diploids in red sea bream, Pagrus major

Abstract

Two types of gynogenetic diploids were arti®cially induced in the red sea bream (Pagrus major Temminck et Schlegel), either by suppressing the ®rst cell cleavage (mitotic-G2N) or by retaining the second polar body (meiotic-G2N). The eggs of red sea bream were inseminated with UV-irradiated (3000 erg mm )2 ) sperm of Japanese parrot ®sh (Oplegnathus fasciatus Temminck et Schlegel), and hydrostatic pressure shock of 700 kg cm )2 for 5.5 min at 46 min after insemination (mitotic-G2N) and cold shock of 1°C for 30 min at 3 min after insemination (meiotic-G2N) were applied to the eggs, sequentially. The total hatching rate and hatching rate of normal larvae of the normal diploid, meiotic-G2N and mitotic-G2N were 86.5 and 94.9%, 38.1 and 45.8%, and 12.8 and 35.0%, respectively. The induction of mitotic-G2N was con®rmed by isozyme marker analysis. The standard deviations, variances and coecients of variation of the body weight, standard length and body depth in 91-day-old juveniles were always large in mitotic-G2N, small in normal-2N and intermediate in meiotic-G2N. The variances in the number of pectoral ®n rays and caudal ®n rays of mitotic-G2N were signi®cantly higher than those of normal-2N. The incidences of deformities were highest in the mitotic-G2N group. The survival rates and growth performance of the meiotic-and mitotic-G2N were signi®cantly lower than those of normal-2N. Both G2N survived for 3 years to the adult stage. Determination of the optimum UV dose to genetically inactivate spermThe 1 ml of sperm of Japanese parrot ®sh was diluted 50-fold in BSS (NaCl, 8.00 g; KCl, 0.45 g; CaCl 2 , 0.20 g; NaHCO 3 , 0.02 g L )1 ), and exposed to ultraviolet (UV) radiation at 65 erg mm )2 s )1 according to the method of Onozato and Yamaha (1983). UV dose was tested between the range of 0±16 000 erg mm )2 (0±263 s). The sperm (2 ml) were used to inseminate about 1300 red sea bream eggs in sea water. Approximately 150 of the eggs were put into two 1-L beakers and incubated at 18°C. The hatching rate of each dose was recorded. Production of meiotic-and mitotic-G2NThe eggs from one female red sea bream were divided into three groups; two groups were inseminated with UV irradiated

Effects of feeding rate on the growth performance of gynogenetic albino sterlet,Acipenser ruthenus(Linnaeus, 1758) larvae

“…Similar results for red sea bream were described by Kato et al. (). A lower survival rate was observed in gynogenetic red sea bream juveniles (1–90 dph) fed Branchinous sp.…”

“…Thus far, similar feeding experiments of chromosome manipulated fish were described for only few teleost such as red sea bream Pagrus major , sea bass Dicentrarchus labrax L., and honmoroko Gnathopogan caerulescens . It has been observed that gynogenetic diploids of red sea bream (Kato, Murata, Yamamoto, Miyashita, & Kumai, ), plaice Pleuronectes platess L. (Purdom, ), and loach (Suzuki, Oshiro, & Nakanishi, ) are characterized by lower growth rates than normal fish. Colombo et al.…”

“…Higher survival rates during early stages of ontogenesis are highly desirable for most fishes. Normally‐fertilized fish larvae possess higher survival rates than do the gynogentic larvae (Chourrout & Quillet, ; Fujioka, ; Kato et al., ; Nagy, Rajki, Horvath, & Csany, ; Peruzzi et al., ; Purdom, ). Semen irradiation and thermal shock to induce the gynogenesis process are main factors in causing a negative impact on the gynogentic larvae survival rate (Fopp‐Bayat & Ocalewicz, ).…”

Induction of diploid gynogenesis in turbot Scophthalmus maximus with left-eyed flounder Paralichthys olivaceus sperm

“…This is likely because of the increased frequencies of some deleteriously homologous recessive genes and lack of paternal DNA in gynogens, which might be essential for larvae to get through the critical stages of early development (Arai 2001;Felip et al 2001). Furthermore, the negative effects of cold stress associated with gynogenesis induction might also lead to the poor survival of diploid gynogens (Kato et al 2001).…”

Construction of an expression vector containing a ?-actin promoter region for gene transfer by microinjection in red sea bream Pagrus major

“…[9][10][11] Red sea bream Pagrus major is one of the most important fish cultured in Japan. To improve the traits of this species, breeding experiments, including mass selection, 12 chromosome manipulation 13,14 and sex control 15 have been conducted. To develop transgenic technology in a new species, transgenic expression vectors with transcriptional activity in the species of choice have to be constructed.…”