Question

Biological Role of Nardonella Endosymbiont in Its Weevil Host.

(Kuriwada et al 2010). Find online to answer.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0013101

(in your own words):

1. the research question / hypothesis of the paper.

  

2. Explain the significance of the data shown in Table 1, with regard to the methodology behind the experiments

  

3. Summarize the results and significance of Figure 3.

  

4. Did the authors actually demonstrate what is suggested in the title of the paper?

  

5. With regard to the weevils, is the relationship obligate or facultative, is the transmission of bacteria between generations horizontal or vertical, and what is the level of specificity between host and bacteria?

6. Describe a future experiment that should be conducted in order to follow up on outstanding questions that pertain to the subject of the

Answer 1

1.The research question / hypothesis of the paper.

            Investigation of the biological role of the Nardonella, an endosymbiont in the weevil host Euscepes postfasciatus (West Indian sweet potato weevil)

2. Explain the significance of the data shown in Table 1, with regard to the methodology behind the experiments

            In order to investigate the symbiotic relationship between Nardonella and sweet potato weevil the larva were fed with antibiotic-containing artificial diet to eliminate Nardonella infection. Table 1 shows the effect of different doses of Rifampicin (an antibiotic)   added to the artificial diet on adult emergence of the potato weevil. The table clearly shows that as the antibiotic doses increase the adult emergence rate decreases, thus they are inversely proportional. As killing the Nardonella has an adverse effect on the emergence rate it can be noted that the Nardonella and the weevil have an symbiotic relationship and that Nardonella species promote the adult emergence rate.

3. Summarize the results and significance of Figure 3.

            Figure 3 is composed of 3 components- Fig. 3A, Fig. 3B and Fig. 3C.

Fig. 3A shows that the number of larvae reaching adulthood is not much different between the offspring of insects infected with Nardonella and non infected insects(antibiotic treated). The number of larvae reaching adulthood were slightly higher in control irrespective of the gender.

Fig. 3B shows a drastic wet weight difference between the offspring of Nardonella-free insects and the offspring of Nardonella-infected insects.

Fig. 3C shows a difference of 9 days developmental time between them. The mean developmental time of control insects(containing Nardonella) is 50 days but antibiotic treated insects take a longer time (59 days)

4. Did the authors actually demonstrate what is suggested in the title of the paper?

Yes the authors have demonstrated what was suggested in the title of the paper. They have investigated the symbiotic assiotiation between Nardonella and Euscepes postfasciatus. They have treated the weevil with antibiotics to control the growth of Nardonella in the weevil which in turn produced adverse effects in proper development of the weevil. This paper proves that the Nardonella has a positive effect on the body weight, body size and growth rate of its host.