In-vivo Mice Pre-Implantation Embryo Development after Oral Administration Ethanolic Extract of Cogon Grass Roots (Imperata cylindrica L)

Cogon grass (Imperata cylindrica L) is known as a medicinal plant that is scattered almost worldwide. Despite its role that inhibits another plant’s growth, cogon grass possesses several benefits in health. This research has to identify the effect of short-term gavage ethanolic extract of cogon grass roots (CGG) to in-vivo mice preimplantation embryo development. A total of 60 female mice were divided into control and treatment groups, dosages at 90 and 115 mg/kg of body weight of CGG, orally gavage for 20 days. The superovulation of mice was done at the end of the CGG treatment by injecting 5 IU Pregnant Mare Serum Gonadotropin (PMSG) and after 48 hours, followed by 5 IU Human Chorionic Gonadotropin (hCG) injection and directly the mice were mated. The mating rate was checked by the appearance of the vaginal plug 12 hours after hCG injection. Mice were sacrificed, the oviducts and cornua of uteri were isolated to collect the oocytes and embryonic cells by flushing the oviducts and cornua uteri with Phosphate-buffered saline (PBS). The effects of CGG as an antifertility were evaluated by measuring the number of oocytes, fertilization, and in-vitro embryo development rates. The results showed significantly reduced about half of the mating rate in the 115 mg/kg BW group (p<0.05) compared to control. However, the 90 mg/kg BW dose reduced 20% mating rate compared to control, and not significant (p>0.05). In all treatment groups, only half oocytes fertilized. The cleavage and blastocyst rate in 115 mg/kg BW group were significantly lower compared to the control group (p<0.05). In conclusion, oral gavage of cogon grass root ethanolic extract disrupts the mating process and development of in-vivo mice preimplantation embryo development.

Improving the sexual activity and reproduction of female zebrafish with high testosterone levels

High levels of testosterone cause clinical symptoms in female reproduction and possibly, alterations in sexuality. Yet, the underlying mechanisms remain to be examined. Here, we report a study that investigates the effects of testosterone in follicle development and sexual mating using zebrafish models. We developed an acute zebrafish model with high testosterone levels by exposing young female zebrafish to testosterone dissolved in swimming water. After given a high concentration of testosterone treatment (e.g., 100 ng/ml), the fish showed hallmark pathological symptoms similar to those displayed in patients with polycystic ovary syndrome (PCOS), such as follicular growth-arrest, rare ovulation, ovary enlargement, decrease in reproduction, and down regulation of the expression of some PCOS susceptible genes, such as Tox3. These fish are referred to as the PCOS fish. By monitoring mating-like swimming behaviors, we measured the sexual activity of PCOS zebrafish. In general, the PCOS fish showed no desire to interact with males. As a consequence, their mating rate was decreased as compared to control animals. The sexuality levels of PCOS fish, however, could be improved after short periods of rearing in conditions that lack of males. After only 3 days of rearing alone, the PCOS fish showed an increase in sexuality levels and displayed characteristic swimming patterns for mating. After 30 days of separation from males, not only the sexual activity, but also the mating rate was improved in the PCOS fish. Together, the data suggests that zebrafish can serve as a new type of research model to further develop strategies for the treatment of reproductive disorders, such as those related to PCOS.

The Drosophila Suzukii Mating Rate Decrease for the Reproductive Interference of Drosophila Melanogaster

Background: Drosophila suzukii has been widely distributed all over the world since 2008, and it is a harmful pest causing great economic loss in many countries. Previous research has found that the presence of Drosophila melanogaster could reduce the emergence and egg laying of Drosophila suzukii. In order to figure out the potential mechanism of this phenomenon, we studied three potential factors including lifetime, larval interspecific competition, and reproductive interference. Results: The results show that the Drosophila suzukii offspring number was significantly decreased when reared with Drosophila melanogaster. The lifetime and larval interspecific competition have no significant effect on the Drosophila suzukii population. Surprisingly, Drosophila melanogaster can cause reproductive interference with male Drosophila suzukii, which leads to a significant decline in the successful mating rate of the latter fruit fly. Conclusions: The presence of Drosophila melanogaster causes the Drosophila suzukii population to decrease through the effect of reproductive interference, and the Drosophila suzukii successful mating rate is significantly decreased for the existence of Drosophila melanogaster.

Characteristics of the Two Asian Bumblebee Species Bombus friseanus and Bombus breviceps (Hymenoptera: Apidae)

This study compared the food plants, life cycle, colony development, and mating behaviour of the two Asian bumblebee species Bombus friseanus and B. breviceps, which are very important pollinators for many wild flowers and crops in local ecosystems. Both species were shown to be highly polylectic. Differences were observed in their life cycles and colony development patterns. The colony foundation rate of the field-collected queens was high in both species, 95.5% in B. friseanus and 86.5% in B. breviceps. The intervals from colony initiation to colony sizes of 30, 60, and 80 workers and to the first male and gyne emergence were significantly shorter in B. friseanus than in B. breviceps (p < 0.01). The development period of the first batch of workers showed no significant difference between the two species (p > 0.05). Compared with B. friseanus, B. breviceps produced remarkably higher numbers of workers (135 ± 30 workers/colony in B. friseanus and 318 ± 123 workers/colony in B. breviceps) and males (199 ± 46 males/colony in B. friseanus and 355 ± 166 males/colony in B. breviceps) (p < 0.01), with notable variation was found among the colonies in both species. With no significant difference in the mating rate between these two species, the copulation duration of B. breviceps (1.54 ± 0.63 min) was strikingly shorter than that of B. friseanus (27.44 ± 11.16 min) (p < 0.001). This study highlights the characteristics of the two Asian bumblebee species and will aid further studies on their conservation and agricultural pollination use.

Successful mating and hybridisation in two closely related flatworm species despite significant differences in reproductive morphology and behaviour

Speciation is usually a gradual process, in which reproductive barriers between two species accumulate over time. Reproductive traits, like genital morphology and mating behaviour, are some of the fastest diverging characters and can serve as reproductive barriers. The free-living flatworm Macrostomum lignano, an established model for studying sex in hermaphrodites, and its congener M. janickei are closely related, but differ substantially in their male intromittent organ (stylet) morphology. Here, we examine whether these morphological differences are accompanied by differences in behavioural traits, and whether these could represent barriers to successful mating and hybridization between the two species. Our data shows that the two species differ in many aspects of their mating behaviour, with M. janickei having a five-fold longer copulation duration, copulating less frequently, and having a longer and more delayed suck behaviour (a postcopulatory behaviour likely involved in sexual conflict). Interestingly, and despite these significant morphological and behavioural differences, the two species mate readily with each other in heterospecific pairings, often showing behaviours of intermediate duration. Although both species have similar fecundity in conspecific pairings, the heterospecific pairings revealed clear postmating barriers, as only few heterospecific pairings produced F1 hybrids. These hybrids had a stylet morphology that was intermediate between that of the parental species, and they could successfully backcross to both parental species. Finally, in a mate choice experiment we tested if the worms preferentially mated with conspecifics over heterospecifics, since such a preference could represent a premating barrier. Interestingly, the experiment showed that the nearly two-fold higher mating rate of M. lignano caused it to mate more with conspecifics, leading to assortative mating, while M. janickei ended up mating more with heterospecifics. Thus, while the two species can hybridize, the mating rate differences could possibly lead to higher fitness costs for M. janickei compared to M. lignano.

Genetic variation and outcrossing rate of Dipterocarpus dyeri in the Tan Phu tropical rain forest (Dong Nai), Vietnam

Dipterocarpus dyeri (Dipterocarpaceae) is widely distributed in lowland rainforests in southeastern Vietnam. Due to over- exploitation and habitat destruction in the 1980s and 1990s, this species is listed as threatened. Understanding the genetic variation and mating rate among D. dyeri population that occurs in forest patches is necessary to establish effectively conservation strategies for this species. To conserve the species in tropical forests, genetic diversity and mating rate were investigated using eight microsatellites (single sequence repeat, SSR) as markers. All of the eight loci were polymorphic. A total of 36 different alleles were observed across the loci screened. The SSR data indicated high genetic diversity (NA = 4.5; HO = 0.542 and HE = 0.667) and high inbreeding value, FIS= 0,182. The mating system parameters were determined using the mixed mating model and the results indicated high outcrossing rate (tm=0.81 and ts=0.675) and lowselfing rate (0.19). Difference of tm-ts value indicated that inbreeding contributed to selfing rate for this species in the Tan Phu tropical rain forest. The results reflected that D. dyeri habitat in this area has been restored and the number of individuals was high, about 500 individuals. However, seedlings were not found so far in this study. These results indicated the importance of conserving of the genetic resources of Dipterocarpus dyeri species in the Tan Phu rain forest. The conservation strategy should include an establishment of an ex-situ conservation site with new big population for this species from all genetic groups, which might improve its fitness under different environmental stresses.

Genetic diversity and outcrossing rate of Dipterocarpus dyeri in Ma Da lowland tropical forest (Dong Nai)

Human activities often lead to the disturbed and fragmented habitat and consequently threated species. Dipterocarpus dyeri (Dipterocarpaceae) is widely distributed in lowland rainforests in southeast Vietnam. Due to over- exploitation and habitat destruction in the 1980s and 1990s, the species is listed as threatened. Understanding the genetic variation and mating rate within D. dyeri population that occurs in forest patches is necessary to establish effectively conservation strategies for this species. To conserve the species in tropical forests, genetic diversity and mating rate were investigated on the basis of eight microsatellites (single sequence repeat, SSR). All of the eight loci were polymorphic. A total of 33 different alleles were observed across the screened loci. The SSR data indicated high genetic diversities (NA = 4.1; HO = 0.461 and HE = 0.543) and the inbreeding value was high (0.185). The mating system parameters were determined using the mixed mating model and indicated high outcrossing rates (tm = 0.884 and ts = 0.645). The differences of significant tm - ts value indicated that inbreeding contributed to selfing rate for this species in lowland tropical forests of Ma Da. This study also indicated the importance of conserving the genetic resources of Dipterocarpus dyeri species in Ma Da rainforests. Genetic conservation should derive from correlated outcrossing. The conservation strategy should be established an ex-situ conservation site with new big population for this species from all genetic groups, which might improve its fitness under different environmental stresses.