Vasoactive Intestinal Peptide (VIP) Protects Nile Tilapia (Oreochromis niloticus) against Streptococcus agalatiae Infection

Round 1

Reviewer 1 Report

The manuscript submitted by Zhang et al., presents an original and very interesting study of Vasoactive intestinal peptide (VIP) and VIP precursor gene (On-VIP) in Nile tiplapia during bacterial infection. The  analysis of research material revealed significant role of On-VIP gene in immunization of fish during infection, which for me is the most interesting of the results.
The overall results are very interesting material for further research, especially on the importance of this finding for aquaculture.
Highlighting the importance of the obtained results in an appropriate way and indicating the possibility of their use in aquaculture would make the article appreciated not only by molecular scientists but also by readers dealing with aquaculture and ichthyopathology.

Some remarks that may help to improve the article are listed below.

Title: Maybe add "Vasoactive intestinal peptide (VIP) protects..."

Keywords: add "fish"

Introduction:

Expand the introduction a bit, emphasize the importance of tilapia for the world's aquaculture. Clearly indicate the purpose of the research (research hypothesis), emphasize the novelty of the obtained results.

Figure 8, figure 10, figure 12:

Adjust the scale size for individual factors or organs so that their expression profiles can be more easily compared.

Figure 12:

-enlarge the font in the charts,

-maybe enlarge the whole figure because currently the charts are unreadable,

- adjust the scale range for organs or factors to make it easier to compare the expression

Disscusion:

- Has the effect of On-VIP on the expression of the pathways of immunological processes related to infection with other pathogens been observed in other fish species?Please desciribe if possible.

- Perhaps there are reports from other vertebrates. Please desciribe if possible.

-It is worth emphasizing that this discovery may be important for ichthyopathology, e.g. in the context of other infections (possibly viral) that pose a serious threat to aquaculture.

Conclusions:

Emphasize that these results may be significant for ichthyopathology and aquaculture due to the importance of the species of Nile tilapia to interest the reader other than a molecular biologist.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The paper is focused on the investigation of the vasoactive intestinal peptide (VIP) function in Nile tilapia. The topic is of interest in the field of fish immunology but there are some aspects that should be clarified. Two VIP peptides were identified in the VIP sequence (see Fig. 1A), why only one was studied? Only one receptor has been identified, the two peptides will therefore bind both on the same receptor? As an example, two different receptors were identified in a previous paper: Viral and bacterial septicaemic infections modulate the expression of PACAP splicing variants and VIP/PACAP receptors in brown trout immune organs Gorgoglione et al., 2015 FSI 47: 923-932. To investigate the VIP and VIPR1 protein expression pattern by WB and immunofluorescence, mammalian specific antibodies have been used. Are you sure that they will recognize fish counterparts considering that you evidenced a quite low sequence homology? How have you determined the amount of the VIP peptide to be used in the in vitro (0.1 nmol) and in vivo (5 nmol) experiments? More details of the LPS and the LTA selected in the study should be provided. Which is the rationale to perform the in vitro cell stimulation with VIP for two very short times like 5 min and 30 min? 

 

 

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

After the revision the paper could be accepted for the publication.