Evidence for the conservation of biological activity of ovulation-inducing factor in seminal plasma

Abstract

An ovulation-inducing factor (OIF) in the seminal plasma of llamas and alpacas (induced ovulators) and cattle (spontaneous ovulators) suggests that OIF is a conserved constituent of seminal plasma among mammals. In this study, three experiments were designed to determine the biological effects of OIF in different species. In experiment 1, superstimulated prepubertal female CD-1 mice (nZ36 per group) were given a single 0.1 ml i.p. dose of 1) phosphate-buffered saline (PBS), 2) 5 mg gonadotropin-releasing hormone (GNRH), 3) 5 IU hCG, or 4) llama seminal plasma. The proportion of mice that ovulated was similar among groups treated with GNRH, hCG, or seminal plasma, and all were higher than the saline-treated group (P!0.001). In experiment 2, female llamas (nZ8 or 9 per group) were intramuscularly treated with 1) 2 ml PBS, 2) 1 ml diluted llama seminal plasma, 3) 3 ml equine seminal plasma, or 4) 3 ml porcine seminal plasma. Experiment 3 was the same as experiment 2 except that the dose of equine and porcine seminal plasma was increased to 8 and 10 ml respectively. All llamas that were treated with llama seminal plasma ovulated and none that were treated with saline ovulated (P!0.0001). The proportion of llamas that ovulated in response to equine and porcine seminal plasma was intermediate. We conclude that the mechanism for the biological response to OIF is present in prepubertal CD-1 mice and that OIF is present in equine and porcine seminal plasma.

Overview of New Concepts in Induce Ovulation Triggers in Dromedary Camels

“…Though, the ovulation rate was lower with bull seminal plasma than with species-specific SP, the OIF might be a preserved molecule in seminal plasma among all mammals. Many studies supported hypothesis that OIF in SP is conserved among species, including those considered to be induced ovulators as (camel and cat) as well as spontaneous ovulators (bovine, equine and porcine) ( Johnston et al, 2004;Ratto et al, 2006b;Bogle et al, 2011). OIF is based on the type of stimulus responsible for eliciting GnRH release from the hypothalamus (Bakker and Baum, 2000).In spontaneously ovulating species (human, sheep, goats, cattle, horse, pigs), the releasing of GnRH from the hypothalamus is triggered in the absence of progesterone and exceeding the systemic estradiol concentrations the certain threshold ( Jaffe and Keys, 1974;Chenault et al,1975;Kelly et al, 1988;Turzillo and Nett, 1999).…”

“…It is an effective stimulator of luteinizing hormone (LH) secretion and it effects on ovulation, forming and function of the corpus luteum and acts via a systemic rather than a local pathwayat physiologically relevant doses (Ratto et al, 2006;Fernandez-Baca et al, 1970;Chen et al, 1985). Although the discovery of OIF in seminal plasma of species and categorized as induced ovulators (camel , cat and rabbit), the recent studies support the hypothesis that the OIF in seminal plasma isolated from other species which considered as spontaneous ovulators (cattle horse) (Bogle et al, 2011;Tanco et al, 2012.…”

Efeito da dose de prostaglandina E2 na ovulação de camundongos fêmeas pré-púberes: Estudo piloto

“…No Dia 3, cerca de 15h após a aplicação dos indutores de ovulação, as fêmeas foram mortas através de deslocamento da cervical. Os ovidutos foram coletados e visualizados sob lupa estereomicroscópica para detecção dos complexos cumulus-oócito (CCO) no lúmen do oviduto, pela técnica de transiluminação, de acordo com Bogle et al (2011). Com agulha hipodérmica 22G foi realizada a ruptura do oviduto para efetuar a contagem dos CCOs.…”

The pattern of ovulation in the southern African spiny mouse (Acomys spinosissimus)

“…In induced ovulators, the positive feedback actions of steroid hormones appear to be absent and the surge of GnRH/LH and ultimately ovulation are elicited by copulation. It has long been thought that mounting and stimulation of the vagina and cervix by penile intromission are adequate stimuli for ovulation (Bibeau et al, 1991, Fernandez-Baca et al, 1970, but more recent studies show that an ovulation-inducing factor in the semen also prompts the LH surge and ovulation (Bogle et al, 2011;Silva et al, 2011). In both spontaneous and induced ovulators, progesterone is released by the corpus luteum that forms in the place of the ruptured Graafian follicle.…”

“…Besides for tactile stimulation through penile spines, the ovulation-inducing factor in the seminal fluid appears to aid ovulation. Both the factor and its receptor seem to be conserved across mammals and are found in both spontaneous and induced ovulators (Bogle et al, 2011). The factor works in a dose-dependent manner in induced ovulators, but its role in spontaneous ovulators is unknown (Bogle et al, 2011).…”