Environmental and Genetic (vgll3) Effects on the Prevalence of Male Maturation Phenotypes in Domesticated Atlantic Salmon

Round 1

Reviewer 1 Report

This paper provides valuable insights into the environmental and genetic factors influencing the maturation of male Atlantic salmon. The authors have meticulously evaluated the combined influence of environmental conditions (temperature, photoperiod, etc.) and a specific gene (vgll3) on salmon maturation. This was accomplished by rearing salmon with different vgll3 genotypes under three distinct environmental conditions and assessing their maturation status. The results clearly indicate a significant impact of both environmental conditions and vgll3 genotypes on salmon maturation. These findings deepen our understanding of the environmental and genetic factors affecting salmon maturation and shed light on their interactions, potentially contributing to improved maturation and sex management in salmon aquaculture.

Furthermore, the authors demonstrated that rare XX females could be produced through all-male production using YY males and XX females, and that these females could mate with XY males to produce offspring with an equal sex ratio. While the details of the underlying mechanisms are not fully understood, this presents a fascinating case for furthering our understanding of sex determination mechanisms in this species.

Overall, the study is well-designed, and the authors have made commendable efforts to dissect a complex phenomenon intertwined with multiple factors by glm analysis. While it is challenging to eliminate all confounding factors, the analytical methods and resultant conclusions are generally convincing. Particularly praiseworthy is the authors' commitment to transparency by providing ample supplementary information, including R-scripts and raw data files. This will enable readers to accurately trace and verify the analytical methods, which is highly commendable.

The manuscript is well-written, and I found no significant issues. I don't see any major changes necessary from my end.

While the section about the occasional appearance of XX females in all-male production seemed somewhat divergent from the main focus of the paper, I agree with its inclusion given the intriguing nature of this phenomenon and the potential for further detailed analysis in the future.

On a minor note, I would like to request a correction in the Methods & Materials section where the subheading "2.4." appears to be repeated, causing subsequent numbers to be misaligned. Personally, I would be interested in seeing a QTL analysis using this dataset to investigate associations with genes other than vgll3, but I understand that this goes beyond the scope of the current manuscript, and I look forward to future developments.

In light of the above, I believe that this manuscript is suitable for acceptance following minor revisions.

Author Response

We appreciate the reviewers positive response. We have changed the numbering in the methods section.

Reviewer 2 Report

Dear authors,

Congratulation for your interesting and needed work.

Beyond the targeted objectives, in my opinion, your paper can, base on a short comment, open new direction of studies like: 1. how the fish farms manipulations can impact the natural populations or even ecosystems including their evolutionary perspectives?   2. how the environmental major regulators can affect this taxon population parameters in the condition of major environmental human induced changes?, etc.

May be highlighting in title and keywords the fact that your experiments deal with anthropogenic, semi-natural and may be even natural environments will focus the reader attention about the complexity of your work?

All the best and sucess

Reviewer

Author Response

We appreciate the reviewers positive response. We have now included the terms "temperature", "photoperiod" and "salinity" in the key words, as these relate to the main environmental variables assessed.