Comparison between PMSG‐ and FSH‐induced superovulation for the generation of transgenic rats

Abstract

Superovulation protocols using single injections of pregnant mare's serum gonadotropin (PMSG) or minipumps with follicle-stimulating hormone (FSH) were compared in immature Sprague-Dawley (SD) rats. We used the following criteria: total number of ova, rate of fertilization, in vitro embryo development, sensitivity of zygotes to the microinjection of foreign DNA into the pronucleus, and their in-vivo development after transplantation into the oviduct of a recipient. Female SD rats were stimulated with 15 IU PMSG or 10 mg FSH followed by the injection of human chorionic gonadotropin (hCG) at doses of 20 and 30 IU per female. After hCG administration, they were mated with males of the same strain and sacrificed on day 1 of pregnancy. The percentage of mated animals and the fertilization rate was similar in all groups. In rats given PMSG, the number of ovulated zygotes was hCG dose-dependent. In contrast, the dose of hCG did not influence the efficiency of superovulation in rats given FSH, which was equal to PMSG-treated rats at the optimal dose of hCG. The rates of in vitro blastocyst development (31.4 and 23.3%) and the resistance to microinjection into the pronucleus did also not differ significantly between zygotes of both studied groups. The proportion of offspring developing from microinjected zygotes after oviduct transfer (26.2 and 26.8%, respectively) and the rate of transgene integration per newborns (7.3 and 4.9%, respectively) was similar in both experimental groups. The results of this study demonstrate that superovulation of immature SD rats by PMSG is equally effective as FSH treatment and, thus, preferable for transgenic rat technology due to the lower costs and easier handling.

Estrous Stage- and Animal Age-Independent Superovulation in the BrlHan:WIST@Jcl(GALAS) Rat

“…In rats, on the other hand, the effects of treatment for superovulation show major strain differences [3,12]. This could be one of the reasons for the delay in practical treatment (PMSG administration), or in which gonadotrophins are gradually stimulated by constant infusion of purified FSH with a short half-life via a subcutaneously or intraperitoneally implanted osmotic mini-pump [1,5,11]. However, the superovulatory effect is influenced by rat strain in the above-mentioned cases.…”

“…However, the superovulatory effect is influenced by rat strain in the above-mentioned cases. The other protocol involves the use of immature rats at 4 to 6 weeks of age [1,4,8,11,13,14], which are not regulated by endogenous hormones since rats begin to exhibit stable estrous cycles with a defined 4-day period at around 8 weeks of age. However, the number of collected fertilized eggs is low because immature female rats generally won't mate with adult males [2].…”

PMSG and HCG hormones effect on the development and growth of ovarian follicles

“…In experimental rats group 100 IU/kg PMSG and 48 h later 100 IU/kg HCG intraperitoneally were injected then 100 IU PBS were injected to the control group. 14 …”

“…They found that FSH increases the number of antral and periantral follicles, while LH increases the primary and secondary follicles. 13 Another study by Popova et al 14 14 The objective of this method is to stimulate folliculogenesis and increase the number of oocytes in a cycle. Following hormonal stimulation of ovulation, the levels of ovarian hormones, especially estradiol and progesterone, extend beyond physiological limits.…”

Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs

“…Specifically, eCG or FSH can induce superovulation in rats (Popova et al, 2002), pigs (Manjarin et al, 2009), sheep (Cognie, 1999), and cattle (Small et al, 2009). FSH and LH are both secreted from pituitary gland, and FSH has a short metabolic half-life (Fry et al, 1987).…”