Limited Mating Ability of a Wasp Strain with Rickettsia-Induced Thelytoky

Sexual reproduction is the dominant mode of reproduction in plants and animals; however, some species from various taxonomic groups reproduce asexually. Because some of these asexual species lack DNA recombination and so have low genetic variability, these asexual species are more likely to go extinct than sexual species. Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae) is a solitary endoparasitoid in which both arrhenotokous and thelytokous strains occur in sympatry. The thelytokous strain is infected by a parthenogenesis-inducing Rickettsia bacterium. We investigated whether fertilized progeny can be produced between females and antibiotic-induced males of the thelytokous strain. The males produced by antibiotic treatment showed the same courtship behaviors as the arrhenotokous males, but at a lower rate, and did not produce fertilized progeny. The results confirm that the thelytokous strain has been maintained by a functional apomixis mechanism rather than by occasional sex, preserving a degree of heterozygosity.

Sexual Behavior and its Relationship with Semen QualityParameters in Jaffrabadi Breeding Bulls

The present study was carried out on 80 ejaculates, 20 each from four healthy Jaffrabadi breeding bulls to see the relationship betweensexual behavior and semen quality parameters. The results depicted that the overall mean values of libido score, mating ability score andsexual libido score between bulls. The overall color of semen ranged from thin white to very thick creamy. The overall values for semen volume(ml), pH, sperm concentration (million/mL), mass activity, individual sperm motility (%) and live spermatozoa (%) were 2.99 ± 0.12, 6.80 ± 0.01, 1439.68 ± 48.46, 3.94 ± 0.03, 89.51 ± 0.21 and 95.00 ± 0.19, respectively. The values for semen volume, sperm concentration,mass activity (%) and live sperm (%) differed significantly (p less than 0.05) between bulls. There were significant positive correlations (p LESS THAN 0.01)of libido with mating ability, sexual behavior score and ejaculate volume of semen (r = 0.37 to 0.87), while a negative correlation wasfound with sperm concentration (-0.30). Mating ability was significantly (p less than 0.01) correlated with sexual behavior score and ejaculatevolume (0.78, 0.67), and sexual behavior was correlated with semen volume (0.84). Sperm concentration was significantly (p less than 0.05 correlated with mass activity (0.29), while individual sperm motility was positively (p less than 0.05) correlated with live sperm percentage (0.25).Correlations of libido, reflected the importance of sexual behavior of Jaffrabadi bulls in predicting their future utility as a proficient breeder under AI program.

Acute and Subacute Toxicity of Bisphenol A on Zebrafish (Danio rerio)

In this paper, acute and subacute toxicity effects of on an environmental estrogen, Bisphenol A (BPA), on zebrafish were investigated. The median lethal concentration (LC50) and the median effect concentration (EC50) of BPA to zebrafish embryos and larvae were calculated. Additionally, effects of BPA on vitellogenin (VTG) gene expression and mating ability to adult male zebrafish were investigated for subacute toxicity analysis. Differed from previous studies on toxicity of BPA, acetone, a relative low-level toxic solution, was adopted as the carrier solvent of BPA in this study. Results showed that the values of 24h、48h and 72h LC50 of BPA on zebrafish embryos and larvae were 16.667mg/l, 9.944 mg/ l, 8.222 mg/l and 20.938 mg/l, 15.170 mg/l, 10.943 mg/l, respectively. The values of 24h and 48h EC50 of BPA on zebrafish embryos were 11.111mg/l and 8.183mg/l, while the valuSubscript textes of 24h, 48h and 72h EC50 of BPA on zebrafish larvae were 14.56mg/l, 12.133mg/l and 9.658mg/l, respectively. Subacute toxicity analysis demonstrated VTG gene was induced in male zebrafish by BPA and the increasing of its expression was both time- and dose-dependent. In addition, BPA could severely inhibit the mating ability of adult male zebrafish and a positive relevance was found between the inhibition and the concentration of BPA exposed.